Littérature scientifique sur le sujet « Profil de variance »
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Articles de revues sur le sujet "Profil de variance"
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Apriliyani, Nur Indah, Muhammad Anwar Djaelani et Silvana Tana. « Profil Histologi Duodenum Berbagai Itik Lokal Di Kabupaten Semarang ». Bioma : Berkala Ilmiah Biologi 18, no 2 (21 avril 2018) : 144. http://dx.doi.org/10.14710/bioma.18.2.144-150.
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Local duck had been widely cultivated not only as a producer of eggs processed as salted egg but also there are cultivated as broiler ducks. The efforts to improve the productivity of ducks can be seen from the effectiveness of the process of absorption of nutrients in the duodenum, so the use of energy in the metabolic process can be optimized for adding mass and volume of the cell. This study aims to determine the duodenum profile of the histological structure covered the lumen diameter, villous height and number of goblet cells of Magelang ducks, Tegal ducks and Pengging ducks .This study used a completely randomized design (CRD) with three treatments (Magelang ducks, Tegal ducks and Pengging ducks) and 6 replications. The measured variable was the long intestine tenue, lumen diameter, villous height and number of goblet cells. Data were analyzed using analysis of variance (ANOVA) with a differentiation factor was the type of duck. The realdifferences data were analyzed using advanced test of Duncan at the level of 95%. The results showed long intestine tenue, lumen diameter and height of the villi were not significantly different at each Magelang ducks, Tegal ducks, Pengging ducks. The number of goblet cells in Magelang ducks and Tegal ducks showed significantly different, but not on Pengging Ducks. The conclusion of the study was the length of the intestine tenue, lumen diameter and height of villous had no real effect on three types of ducks. Keywords: Local ducks, duodenum, histological
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Adawyah, Rabiatul, Ulil Amri, Widya Ramadhini, El Redha El Redha et Findya Puspitasari. « PENGARUH LAMA WAKTU PENGGARAMAN YANG BERBEDA TERHADAP KADAR PROTEIN DAN ASAM AMINO CUMI-CUMI (LOLIGO SP.) ». Fish Scientiae 11, no 2 (13 février 2022) : 159–66. http://dx.doi.org/10.20527/fishscientiae.v11i2.178.
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Cumi-cumi (Loligo sp.) merupakan binatang lunak dengan tubuh berbentuk silindris. Sirip-siripnya berbentuk triangular atau radar yang menjadi satu pada ujungnya. Pada kepalanya disekitar lubang mulutnya terdapat 10 tentakel yang dilengkapi dengan alat penghisap (sucker) dan merupakan sumber protein hewani yang mana komponen utama penyusun proteinnya adalah asam amino. Penelitian ini bertujuan untuk mengetahui pengaruh lama waktu penggaraman yang berbeda pada proses pengolahan cumi-cumi terhadap kadar protein dan profil asam amino. Hasil penelitian menunjukkan bahwa perlakuan lama waktu penggaraman yang berbeda memberikan pengaruh yang tidak berbeda nyata terhadap kadar protein berdasarkan hasil Analysis of Variance (ANOVA) α 5%. Kesimpulan dari penelitian ini adalah pengaruh lama waktu penggaraman cumi yang berbeda tidak berpengaruh terhadap kadar protein, Hasil analisa kadar protein tertinggi ada pada perlakuan C yaitu penggaraman selama 5 hari sebesar 15,09% sedangkan untuk profil asam amino lisin sebesar 1,38% dari perlakuan 0 yaitu cumi-cumi segar merupakan jenis asam amino esensial tertinggi dari profil asam amino penyusun protein cumi, sedangkan jenis asam amino non esensial tertinggi adalah asam glutamat sebesar 2,79% dari perlakuan 0 yaitu cumi-cumi segar.
The squid (Loligo sp.) Is a soft animal with a cylindrical body. The fins are triangular or radar-shaped which are joined at the ends. On the head around the mouth opening there are 10 tentacles which are equipped with a sucker (sucker) and are a source of animal protein where the main component of protein is amino acids. This study aims to determine the effect of different salting times in the processing of squid on protein content and amino acid profile. The results showed that the different salting time treatments had no significant effect on protein content based on the results of the Analysis of Variance (ANOVA) α 5%. The conclusion of this study is that the effect of different salting time of squid has no effect on protein content.The results of the analysis of the highest protein content were in treatment C, namely salting for 5 days at 15.09%, while for the lysine amino acid profile of 1.38% of the treatment. 0, namely fresh squid is the highest type of essential amino acid from the amino acid profile of squid protein, while the highest type of non-essential amino acid is glutamic acid at 2.79% from treatment 0, namely fresh squid.
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Putra, Mardan Syah, Yusya' Abubakar et Heru Prono Widayat. « Profil Sensori Kopi Blend dari Beberapa Kultivar Arabika Gayo ». Jurnal Teknologi dan Industri Pertanian Indonesia 16, no 1 (5 avril 2024) : 54–61. http://dx.doi.org/10.17969/jtipi.v16i1.25260.
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Coffee diversity contributes significantly to the richness and uniqueness of taste, because each coffee type or cultivar carries out its intrinsic quality as a reflection of its genetic characteristic. The aims of this study is to examine the effect of blending of several Gayo Arabica coffee cultivars on the coffee brew sensory profile. This study uses quantitative descriptive analysis (ADK). Experimental design used is one factor ANOVA with 7 combination ratio. Combination of 3 and 2 cultivars were also to be analyzed with different mixing of 3 and 2 cultivars. The samples were then tested for taste including Aroma, Flavor, Aftertaste, Acidity, Body, Balance, and Overall by expert panelists. The data were analyzed using the Mann-Whitney test because the data did not have a normal/nonparametric distribution. The results of the analysis of variance showed that there was no significant difference between the blending treatment and the control treatment on the taste quality scores tested (P0.05). Based on the descriptive, there is a difference in the taste quality score between the blending treatment and the control treatment on the total score of Gayo Arabica coffee taste quality.
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Restiana, Nena. « EVALUASI PROFIL TPACK UNTUK GURU MATEMATIKA SEKOLAH MENENGAH PERTAMA DI BANTEN ». Jurnal Penelitian Pendidikan 35, no 2 (1 octobre 2018) : 167–78. http://dx.doi.org/10.15294/jpp.v35i2.14438.
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Information and Communication Technology (ICT) has an influence overall areas, as well as on learning. Learning is required to adjust the development of ICT to make learning more effective and dynamic. Constraints faced in the implementation of ICT. It is the underlying to do research related to the teacher's understanding of technology. This study will analyze the profile of technological understanding of juniorhigh school mathematics teachers using TPACK framework. Furthermore, age factor, length of teaching, and gender are analyzed its effect on TPACK using analysis of variance (ANOVA). The results of this study are six validated TPACK components, obtained five components namely TK, CK, PCK, TPTCK, TPCK. Based on the TPACK framework of junior high school mathematics teachers in Banten obtained the highest average score on the CK component. Age factor, duration of teaching and gender have no significant effect or only small effect on the five components of TPACK
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Basri, Hasan, et Rosalina Edy Swandayani. « PEMBERIAN FORMULA PAKAN HERBAL TERHADAP PROFIL LIPID PADA AYAM PEDAGING ». MEDIA BINA ILMIAH 13, no 12 (23 juillet 2019) : 1847. http://dx.doi.org/10.33758/mbi.v13i12.269.
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This study aims to determine the effect of herbal feeds with different formulas to increase the HSL levels and optimize cholesterol, triglyceride, LDL levels. This study is an experimental study with Completely Randomized Design (CRD). Test animal used in this study were 20 broilers and divided into 4 experimental groups, i.e. P0: control given commercial feed, P1: treatment group given a feed formula, P2: the treatment group given the feed formula, P3: the treatment group given the feed formula. Each group consists of 5 replications. The test animal for each treatment was placed randomly. Data obtained was cholesterol, triglycerides, HDL and LDL levels. The data obtained were analyzed using analysis of variance (ANOVA) and followed by Duncan test with 95% of significance level if there were significant differences. The data were analyzed with SPSS 25 software for Windows. The results showed that the level of cholesterol, triglycerides, HDL and LDL were not significantly different (P> 0.05). The conclusion of this study is that the provision of herbal feed formulas is not significant in reducing cholesterol, triglycerides, LDL, levels and increasing HDL levels, but is able to maintain normal physiological conditions.
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Bels, Vincent L., Charles Brillet et Véronique Delheusy. « Etude cinématique de la prise de nourriture chez Eublepharis macularius (Reptilia, Gekkonidae) et comparaison au sein des geckos ». Amphibia-Reptilia 16, no 2 (1995) : 185–201. http://dx.doi.org/10.1163/156853895x00361.
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AbstractL'étude cinématique des diverses phases de la prise de nourriture (capture, réduction, transport et léchage) a été réalisée chez le lézard Gekkonidae Eublepharis macularius grâce à des films tournés à 64 images par seconde. Les profils cinématiques des différentes phases et la comparaison des variables cinématiques décrivant les déplacements maxima des machoires et de la proie, et les durées de ces déplacements au cours des phases successives de la prise de nourriture sont présentés. Une premiere analyse de variance a été utilisée afin de tester 1'effet des facteurs individus et phases ainsi que leur interaction sur les variables cinématiques. Une seconde a permis de tester le facteur espèce sur les variables cinématiques des mouvements des mâchoires entre deux Gekkonidae occupant des niches écologiques différentes: E. macularius (terrestre) et Phetsuma madagascariensis (arboricole). Les effets de la radiation adaptative sur les propriétés cinématiques des mouvements de la tête, des machoires et de la langue au sein des Gekkonidae et des Scleroglossa sont discutés à partir de ces résultats. En conclusion, (1) le profil des différentes phases de la prise de nourriture est semblable pour les Scleroglossa étudiés, mais 1égèrement différent de celui des Iguania (presence d'un plateau appelé SOII dans le profil d'ouverture-fermeture de la gueule au cours des cycles de transport chez les Scleroglossa, p. ex.), (2) les caractéristiques morphométriques des pièces buccales permettent d'expliquer des différences entre les valeurs des variables cinéma- tiques pour chaque espèce.
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Fanani, Anhar Faisal, Nurul Fajrih et Wa Laili Salido. « Penggunaan Minyak Ikan dalam Ransum Ayam Kampung terhadap Profil Lemak Darah ». Jurnal Ilmu dan Teknologi Peternakan Tropis 6, no 1 (7 février 2019) : 14. http://dx.doi.org/10.33772/jitro.v6i1.5572.
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ABSTRAKTujuan penelitian adalah mengevaluasi level penambahan minyak ikan lemuru dalam ransum ayam kampung terhadap profil lemak darah.Materi penelitian yang digunakan adalahayam kampung betina umur 24 minggu. Bahan pakan yang digunakan adalah minyak ikan lemuru, bekatul, jagung giling, bungkil kedelai, minyak sawit, tepung ikan, dan premix multi mineral dan vitamin. Metode penelitian menggunakan rancangan acak lengkap (RAL). Perlakuan yang diberikan adalah T0 = Penggunaan minyak ikan lemuru sebanyak 0%, T1 = Penggunaan minyak ikan lemuru sebanyak 2%, T2 = Penggunaan minyak ikan lemuru sebanyak 4%, T3 = Penggunaan minyak ikan lemuru sebanyak 6%. Parameter yang diamati adalah kolesterol total, kadar High Density Lipoprotein (HDL) dan Low Density Lipoprotein (LDL) darah ayam kampung. Data dianalisis menggunakan analisis variansi yang dilanjutkan uji duncan.Hasil penelitian menunjukkan bahwa perlakuan dengan minyak ikan lemuru pada level tertinggi berpengaruhnyata (P<0,05) terhadap kolesterol total, kadar HDL dan LDL darah.Kesimpulan penelitian adalah pemberian minyak ikan lemuru sampai 6% dapat digunakan dalam campuran pakan ayam kampung.Kata kunci: Profil lemak darah, ayam lokal, minyak ikan lemuruABSTRACTThe aimed of the study was to evaluate the level of addition lemuru fish oil in the ration of local chicken on the blood fat profile. The research materials used was female local chickens aged 24 weeks. The feed materials used are lemuru fish oil, rice bran, milled corn, soybean meal, palm oil, fish meal as well as multimineral and vitamin premix. The research method using a complete by randomized design. The treatments are given wereT0= lemuru fish oil as much as 0%, T1 = lemuru fish oil as much as 2%, T2 = lemuru fish oil as much as 4%, T3 = lemuru fish oil as much as 6%. The observed variables were total cholesterol, levels of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) of local chicken blood. The data were analyzed using analysis of variance and was continued with Duncan test. The results showed that the treatment with lemuru fish oil at the highest level had a significant effect (P<0.05) on total cholesterol, HDL levels, and LDL blood. The conclusion of the study is that the provision of lemuru fish oil up to 6% can be used in native chicken feed mix.Keywords: The blood fat profile, local chicken, lemuru fish oil
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Yuliani, Yuliani, Muhammad Fahri, Marwati Marwati et Krishna Purnawan Candra. « Profil Organoleptik Dan Kandungan Gizi Naget Ikan Gabus Yang Difortifikasi Kecambah Kacang Hijau ». Jambura Fish Processing Journal 3, no 2 (3 août 2021) : 60–68. http://dx.doi.org/10.37905/jfpj.v3i2.11051.
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Tujuan penelitian ini adalah untuk menganalisis profil organoleptik, kandungan gizi, dan total kalori Naget Ikan Gabus (NIG) dengan fortifikasi Kecambah Kacang Hijau (KKH). Penelitian ini merupakan penelitian faktor tunggal dalam rancangan acak lengkap, dengan enam perlakuan dan setiap perlakuan diulang sebanyak 3 kali. KKH yang ditambahkan adalah 0, 5, 10, 15, 20, dan 25% dari jumlah daging ikan gabus. Data kandungan gizi dan total kalori dianalisis menggunakan Analysis of Variance dilanjutkan dengan uji beda nyata terkecil pada taraf α 5%, sedangkan data organoleptik dianalisis secara deskriptif berdasarkan frekuensi terbanyak (modus). Hasil penelitian menunjukkan bahwa fortifikasi KKH sampai dengan 25% memberikan pengaruh nyata terhadap karakteristik organoleptik dan gizi NIG (p0,05). NIG dengan penambahan KKH sampai dengan 10% mendapat respons disukai untuk atribut aroma, rasa, dan tekstur, sedangkan warna disukai hingga penambahan kecambah kacang hijau sebanyak 25%. NIG yang dihasilkan berwarna kuning keemasan hingga kuning kecokelatan. Semakin tinggi penambahan konsentrasi KKH menyebabkan respons sensoris mutu hedonik untuk aroma dan rasa ikan gabus menurun, sebaliknya respons sensoris mutu hedonik untuk aroma dan rasa KKH menjadi meningkat. Semakin besar penambahan KKH juga meningkatkan kelembutan tekstur NIG, serta meningkatkan kadar Abu; Air, Lemak; dan Protein, tetapi menurunkan kadar Karbohidrat dan total kalori NIG.
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Pasaribu, Arnen, Lollie Agustina P.Putri et Dwi Suryanto. « Identication of Variance Moleculer Genotype Commercial Oil Palm (Elaeis guineensis Jacq.) based on Random Amplified Polymorpism DNA (RAPD) Markers ». INSIST 2, no 1 (1 avril 2017) : 63. http://dx.doi.org/10.23960/ins.v2i1.37.
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Abstract —Commercial oil palm is one of plant genotype have a inbreeding so that it will be genetic depression. Genetic depression can cause difficulties to identification of genetic trait in palm oil, so that identification of moleculer variance is necessary to know the genetic potential of commercial palm oil to obtain initial information about genetic diversity. The objectives of this study was to find genetic diversity in commercial oil palm (E. guineensis Jacq.) by using five RAPD primers (OPC-12, OPH-12, OPC-7, OPI-20 and OPD-16). The results of this study showed that Polymorpism Information Content (PIC) was 0.338. PCoA analysis showed that the moleculer varian was 43,72% and according to profil radial neighbour joining tree (NJtree) showed that three main groups. Keywords—Genetic Variation,Oil Palm , RAPD
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Putri, Fitria Tridyana, Edhy Sudjarwo et Osfar Sjofjan. « The Effect of Dietary Candlenut Powder on Blood Profile and Meat Cholesterol Content of Broilers ». Jurnal Agripet 18, no 1 (1 avril 2018) : 63–66. http://dx.doi.org/10.17969/agripet.v18i1.11188.
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ABSTRACT. The purpose of this research was to investigate the use of candlenut powder (Aleurites mollucana (L.) Willd.) as feed additive on blood profile and meat cholesterol content of broilers. Materials used in this research were 200 day-old broiler chicks. Research method was in vivo on Completely Randomized Design with 5 treatments (P0 = basal diets only, P1 = basal diets + 0.25% candlenut powder, P2 = basal diets + 0.5% candlenut powder, P3 = basal diets + 0.75% candlenut powder, P4 = basal diets + 1% candlenut powder), each treatment was replicated 5 times. Variables measured were blood profile (erythrocyte, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin) and meat cholesterol content. Data were analyzed by using Analysis of Variance. Data with significant different effects were further analyzed by using Duncan’s Multiple Range Test. The results showed that candlenut powder usage as feed additive had a highly significant effect on (P0.01) erythrocyte and hemoglobin levels. Candlenut powder also significantly affect (P0.05) mean corpuscular hemoglobin (MCH), but did not significantly affect (P0.05) mean corpuscular volume (MCV) levels. Broilers fed candlenut powder had lower (P0.01) meat cholesterol content compared to those fed basal diets only. It might be concluded that the use of candlenut powder as feed additive at the level of 1% is safely recommended to give better blood profile and reduce meat cholesterol content of broilers.Pengaruh penambahan tepung biji kemiri terhadap profil darah ayam pedaging dan kandungan kolesterol dagingABSTRAK. Tujuan penelitian ini untuk mengevaluasi pemanfaatan tepung biji kemiri (Aleurites mollucana (L.) Willd.) sebagai aditif pakan terhadap profil darah dan kandungan kolesterol daging ayam pedaging. Materi yang digunakan adalah 200 ekor day old chicks (DOC) ayam pedaging. Metode penelitian menggunakan percobaan in vivo pada Rancangan Acak Lengkap (RAL) dengan 5 perlakuan (P0 = pakan basal, P1 = pakan basal + 0.25% tepung biji kemiri, P2 = pakan basal + 0.5% tepung biji kemiri, P3 = pakan basal + 0.75% tepung biji kemiri, P4 = pakan basal + 1% tepung biji kemiri), setiap perlakuan diulang sebanyak 5 kali. Data dianalisis menggunakan analisis variansi (ANOVA) perbedaan yang signifikan dilanjutkan dengan Uji Jarak Berganda Duncan’s. Hasil penelitian menunjukkan bahwa pemanfaatan tepung biji kemiri sebagai aditif pakan memberikan perbedaan yang sangat nyata (P0,01) terhadap jumlah eritrosit dan hemoglobin. Tepung biji kemiri juga memberikan pengaruh yang nyata (P0,05) terhadap mean corpuscular hemoglobin (MCH), tetapi tidak memberikan pengaruh yang nyata terhadap mean corpuscular volume (MCV) darah ayam. Ayam pedaging yang diberi pakan dengan penambahan tepung biji kemiri memiliki kandungan kolesterol daging yang lebih rendah (P0,01) dibandingkan dengan yang hanya diberi pakan basal. Kesimpulan dari penelitian ini adalah bahwa penambahan tepung biji kemiri sebanyak 1% dapat memberikan profil darah yang lebih baik dan efektif untuk menurunkan kandungan kolesterol daging ayam pedaging.ABSTRACT. The purpose of this research was to investigate the use of candlenut powder (Aleurites mollucana (L.) Willd.) as feed additive on blood profile and meat cholesterol content of broilers. Materials used in this research were 200 day-old broiler chicks. Research method was in vivo on Completely Randomized Design with 5 treatments (P0 = basal diets only, P1 = basal diets + 0.25% candlenut powder, P2 = basal diets + 0.5% candlenut powder, P3 = basal diets + 0.75% candlenut powder, P4 = basal diets + 1% candlenut powder), each treatment was replicated 5 times. Variables measured were blood profile (erythrocyte, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin) and meat cholesterol content. Data were analyzed by using Analysis of Variance. Data with significant different effects were further analyzed by using Duncan’s Multiple Range Test. The results showed that candlenut powder usage as feed additive had a highly significant effect on (P0.01) erythrocyte and hemoglobin levels. Candlenut powder also significantly affect (P0.05) mean corpuscular hemoglobin (MCH), but did not significantly affect (P0.05) mean corpuscular volume (MCV) levels. Broilers fed candlenut powder had lower (P0.01) meat cholesterol content compared to those fed basal diets only. It might be concluded that the use of candlenut powder as feed additive at the level of 1% is safely recommended to give better blood profile and reduce meat cholesterol content of broilers.
Thèses sur le sujet "Profil de variance"
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Vaníček, Jakub. « Měření relativní variance optické intenzity ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219091.
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The intention of this master‘s thesis is the measurment of relative variance of optical intensity. In the first place, I have been studied Kolmogorov cascade theory of turbulence and relative variance of optical intensity . In addition, I have been deal with turbulent cells, Gaussian beam, Top Hat beam and influence of the atmospheric turbulences on the intensity profile of the laser beam. Lastly I have been measured determine influence of the atmospheric turbulences on the intensity profile of the laser beam and I have been calculated relative variance of optical intensity. I have suggested the optimum beam profile in the turbulent atmosphere from acquired data.
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Tergny, Guillaume. « Allocation dynamique de portefeuille avec profil de gain asymétrique : risk management, incitations financières et benchmarking ». Phd thesis, Conservatoire national des arts et metiers - CNAM, 2011. http://tel.archives-ouvertes.fr/tel-00629049.
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Les gérants de portefeuille pour compte de tiers sont souvent jugés par leur performance relative à celle d'un portefeuille benchmark. A ce titre, ils sont amenés très fréquemment à utiliser des modèles internes de "risk management" pour contrôler le risque de sous-performer le benchmark. Par ailleurs, ils sont de plus en plus nombreux à adopter une politique de rémunération incitative, en percevant une commission de sur-performance par rapport au benchmark. En effet, cette composante variable de leur rémunération leur permet d'augmenter leur revenu en cas de sur-performance sans contrepartie en cas de sous-performance. Or de telles pratiques ont fait récemment l'objet de nombreuses polémiques : la période récente de crise financière mondiale a fait apparaître certaines carences de plusieurs acteurs financiers en terme de contrôle de risque ainsi que des niveaux de prise de risque et de rémunération jugés excessifs. Cependant, l'étude des implications de ces pratiques reste un thème encore relativement peu exploré dans le cadre de la théorie classique des choix dynamiques de portefeuille en temps continu. Cette thèse analyse, dans ce cadre théorique, les implications de ces pratiques de "benchmarking" sur le comportement d'investissement de l'asset manager. La première partie étudie les propriétés de la stratégie dynamique optimale pour l'asset manager concerné par l'écart entre la rentabilité de son portefeuille et celle d'un benchmark fixe ou stochastique (sur ou sous-performance). Nous considérons plusieurs types d'asset managers, caractérisés par différentes fonctions d'utilité et qui sont soumis à différentes contraintes de risque de sous-performance. Nous montrons en particulier quel est le lien entre les problèmes d'investissement avec prise en compte de l'aversion à la sous-performance et avec contrainte explicite de "risk management". Dans la seconde partie, on s'intéresse à l'asset manager bénéficiant d'une rémunération incitative (frais de gestion variables, bonus de sur-performance ou commission sur encours additionnelle). On étudie, selon la forme de ses incitations financières et son degré d'aversion à la sous-performance, comment sa stratégie d'investissement s'écarte de celle de l'investisseur (ou celle de l'asset manager sans rémunération incitative). Nous montrons que le changement de comportement de l'asset manager peut se traduire soit par une réduction du risque pris par rapport à la stratégie sans incitation financière soit au contraire par une augmentation de celui-ci. Finalement, nous montrons en quoi la présence de contraintes de risque de sous-performance, imposées au gérant ou traduisant son aversion à la sous-performance, peut être bénéfique à l'investisseur donnant mandat de gestion financière.
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Bavay, Cécile. « Adaptation des méthodologies d’évaluation sensorielle aux produits agroalimentaires à forte variabilité ». Angers, 2013. https://theses.hal.science/tel-00846841.
Texte intégralRésumé :
Les caractéristiques sensorielles peuvent être mesurées par des méthodes descriptives d'évaluation sensorielle, parmi lesquelles le profil conventionnel. Les résultats sensoriels de profil présentent une forte variabilité, due, d'une part aux différences entre les sujets du panel, et d'autre part à la variabilité intra-lot, et notamment aux différences existant entre les individus d'un échantillon. À ce jour, la variabilité des sujets est prise en compte et les méthodologies de collecte et d'analyse des données ont été adaptées dans ce but. Néanmoins, la variabilité intra-lot n'a pas été abordée, malgré le challenge qu'elle représente. Avec pour produit modèle la pomme, ce travail de thèse aborde la problématique de la variabilité intra-lot sous deux angles : la mesure de la variabilité et la réduction de la variabilité, dans le but d'obtenir une mesure sensorielle plus fiable. Premièrement, la capacité de discrimination du panel a été observée entre les variétés étudiées et entre les fruits de chaque variété, identifiés comme différents selon une mesure instrumentale. Deuxièmement, afin de prendre en compte la variabilité intra-lot, le modèle d'analyse de la variance classiquement utilisé en évaluation sensorielle a été adapté avec l'ajout d'un facteur fruit hiérarchisé au facteur variété. Cette adaptation implique le partage de chaque fruit par plusieurs sujets. L'application de ce modèle a démontré l'importance de la variabilité intra-lot et l'importance du choix du modèle pour obtenir des résultats plus pertinents. De plus, le modèle d'analyse de la variance déterminé a été adapté afin de distinguer désaccord pur entre les sujets et différences de dispersion. Enfin, une réduction de la variabilité effective est obtenue par le partage des fruits ou par une homogénéisation instrumentale, cette dernière étant dépendante de la variété et de la mesure choisie. Les résultats de ce travail apportent des clés méthodologiques pour l'obtention de résultats fiables dans la cadre de l'évaluation sensorielle de produits variablesThe sensory characteristics are evaluated by descriptive methods of sensory evaluation, such as the conventional profile. The sensory results from profiling present a large variability, due to differences between assessors on the one hand, and within-batch variability, that is differences between units of a sample, on the other hand. To date, differences between assessors are taken into account and sensory methodologies have been adapted for that. Nevertheless, within-batch variability has not been tackled, despite the challenge it represents. With the apple as a model, this PhD work addresses the issue of within-batch variability from two points of view: the measuring of variability and the reduction of variability, with the aim of improving the reliability of the sensory measure. First, the capacity of the panel to discriminate between apples from different cultivars and between apples, identified as different by an instrumental measure, within each cultivar has been observed. Second, in order to take within-batch variability into account, the standard models for analysis of variance used in sensory evaluation has been adapted by adding a fruit factor nested within the cultivar factor. This adaptation requires the sharing of each piece of fruit by several assessors. The application of this model has demonstrated the importance of within-batch variability and the consequence of model choice to obtain more relevant results. In addition, the determined model for analysis of variance has been adapted to distinguish between assessors' disagreement and scaling differences. Finally, a reduction of variability has been obtained through the sharing of fruits and after the homogenization by instrumental measurement, the latter depending on the cultivar and on the chosen measure. The results of the present work provide methodological keys to obtain reliable sensory results in the frame of the evaluation of products subject to biological variation
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Abrhám, Ondřej. « Odhad měsíčních odchylek závodových nákladů dle nákladových skupin - analýza postupu a návrh zlepšení ». Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-5252.
Texte intégralRésumé :
Theory: - Controlling - its function and structure - Costs Analytical part: - Cost variance tracking and evaluation of its monthly prediction - Proposal of best practices for cost variance prediction done on monthly basis
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Bavay, Cécile. « Adaptation des méthodologies d'évaluation sensorielle aux produits agroalimentaires à forte variabilité ». Phd thesis, Université d'Angers, 2013. http://tel.archives-ouvertes.fr/tel-00846841.
Texte intégralRésumé :
Les caractéristiques sensorielles peuvent être mesurées par des méthodes descriptives d'évaluation sensorielle, parmi lesquelles le profil conventionnel. Les résultats sensoriels de profil présentent une forte variabilité, due, d'une part aux différences entre les sujets du panel, et d'autre part à la variabilité intra-lot, et notamment aux différences existant entre les individus d'un échantillon. À ce jour, la variabilité des sujets est prise en compte et les méthodologies de collecte et d'analyse des données ont été adaptées dans ce but. Néanmoins, la variabilité intra-lot n'a pas été abordée, malgré le challenge qu'elle représente. Avec pour produit modèle la pomme, ce travail de thèse aborde la problématique de la variabilité intra-lot sous deux angles : la mesure de la variabilité et la réduction de la variabilité, dans le but d'obtenir une mesure sensorielle plus fiable. Premièrement, la capacité de discrimination du panel a été observée entre les variétés étudiées et entre les fruits de chaque variété, identifiés comme différents selon une mesure instrumentale. Deuxièmement, afin de prendre en compte la variabilité intra-lot, le modèle d'analyse de la variance classiquement utilisé en évaluation sensorielle a été adapté avec l'ajout d'un facteur fruit hiérarchisé au facteur variété. Cette adaptation implique le partage de chaque fruit par plusieurs sujets. L'application de ce modèle a démontré l'importance de la variabilité intra-lot et l'importance du choix du modèle pour obtenir des résultats plus pertinents. De plus, le modèle d'analyse de la variance déterminé a été adapté afin de distinguer désaccord pur entre les sujets et différences de dispersion. Enfin, une réduction de la variabilité effective est obtenue par le partage des fruits ou par une homogénéisation instrumentale, cette dernière étant dépendante de la variété et de la mesure choisie. Les résultats de ce travail apportent des clés méthodologiques pour l'obtention de résultats fiables dans la cadre de l'évaluation sensorielle de produits variables.
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Fabien, Bernard. « IDADIGE : Procédé de traitement des images de gels d'électrophorèse bidimensionnelle différentielle dans le contexte de la recherche de marqueurs protéiques ». Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00799838.
Texte intégralRésumé :
Le sujet de cette thèse s'inscrit dans le cadre du projet NODDICCAP initié par l'entreprise bioMérieux et visant le développement de Nouveaux Outils pour le Dépistage, le DIagnostic, l'évaluation du pronostic et le suivi du Cancer Colorectal par une Approche Protéomique. Le développement de ces nouveaux outils passe nécessairement par l'identification de marqueurs tumoraux discriminants et spécifiques du cancer colorectal. L'objectif de la thèse a été d'optimiser l'analyse des images et des données issues de la technologie DIGE (Differential In-Gel Electrophoresis), afin de permettre la découverte de marqueurs potentiels du cancer colorectal. Après avoir identifié les maillons faibles de la chaîne de traitement classique des images de gel d'électrophorèse 2D, nous avons été amenés à reconsidérer les approches utilisées et à rechercher des méthodes de traitement d'image et de données innovantes, ou bien existantes mais issues de domaines voisins. Le choix des méthodes a été guidé par l'évaluation de leur efficacité en comparaison aux méthodes classiquement employées, et également par les contraintes liées au contexte biologique et technologique. Les principales avancées issues de ce travail sont la définition du schéma expérimental, l'approche stratégique de l'analyse d'images ainsi que l'analyse statistique des données. En ce qui concerne le schéma expérimental, le choix d'une lignée cellulaire comme standard commun a permis un meilleur recoupement des données entre différentes expériences. L'analyse stratégique de l'analyse d'image a été améliorée grâce à l'utilisation d'un patron de détection unique. Ce patron unique a été réalisé à l'aide d'une méthode de fusion d'images originale permettant une juste représentativité de chacune des tâches protéiques de l'ensemble des images considérées. Enfin, les méthodes pour l'analyse statistique des données ont tenu compte de l'intensité des tâches protéiques grâce à une régulation de la variance lors de la comparaison des ratios. Par ailleurs, la spécification par le biologiste d'un profil de risque a permis, par exemple, de porter une plus grande attention aux protéines fortement exprimées. L'ensemble des méthodes mises en place depuis l'acquisition des images jusqu'à la découverte et la visualisation des marqueurs protéiques potentiels constitue le workflow IDADIGE (Image and Data Analysis for Differential In Gel Electrophoresis). Ce workflow exploite différents logiciels ainsi que plusieurs fonctions implémentées sous Matlab et regroupées sous le nom ProDIGE. L'exploitation par le laboratoire de protéomique de bioMérieux du workflow IDADIGE a été utilisée en routine et a permis la découverte de marqueurs protéiques du cancer colorectal qui doivent maintenant être validés biologiquement.
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Bernard, Fabien. « IDADIGE : Procédé de traitement des images de gels d'électrophorèse bidimensionnelle différentielle dans le contexte de la recherche de marqueurs protéiques ». Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00509768.
Texte intégralRésumé :
Le sujet de cette thèse s'inscrit dans le cadre du projet NODDICCAP initié par l'entreprise bio-Mérieux et visant le développement de Nouveaux Outils pour le Dépistage, le DIagnostic, l'évaluation du pronostic et le suivi du Cancer Colorectal par une Approche Protéomique. Le développement de ces nouveaux outils passe nécessairement par l'identification de marqueurs tumoraux discriminants et spécifiques du cancer colorectal. L'objectif de la thèse a été d'optimiser l'analyse des images et des données issues de la technologie DIGE (Differential In-Gel Electrophoresis), afin de permettre la découverte de marqueurs potentiels du cancer colorectal. Après avoir identifié les maillons faibles de la chaîne de traitement classique des images de gel d'électrophorèse 2D, nous avons été amenés à reconsidérer les approches utilisées et à rechercher des méthodes de traitement d'image et de données innovantes, ou bien existantes mais issues de domaines voisins. Le choix des méthodes a été guidé par l'évaluation de leur efficacité en comparaison aux méthodes classiquement employées, et également par les contraintes liées au contexte biologique et technologique. Les principales avancées issues de ce travail sont la définition du schéma expérimental, l'approche stratégique de l'analyse d'images ainsi que l'analyse statistique des données. En ce qui concerne le schéma expérimental, le choix d'une lignée cellulaire comme standard commun a permis un meilleur recoupement des données entre différentes expériences. L'analyse stratégique de l'analyse d'image a été améliorée grâce à l'utilisation d'un patron de détection unique. Ce patron unique a été réalisé à l'aide d'une méthode de fusion d'images originale permettant une juste représentativité de chacune des tâches protéiques de l'ensemble des images considérées. Enfin, les méthodes pour l'analyse statistique des données ont tenu compte de l'intensité des tâches protéiques grâce à une régulation de la variance lors de la comparaison des ratios. Par ailleurs, la spécification par le biologiste d'un profil de risque a permis, par exemple, de porter une plus grande attention aux protéines fortement exprimées. L'ensemble des méthodes mises en place depuis l'acquisition des images jusqu'à la découverte et la visualisation des marqueurs protéiques potentiels constitue le workflow IDADIGE (Image and Data Analysis for Differential In Gel Electrophoresis). Ce workflow exploite différents logiciels ainsi que plusieurs fonctions implémentées sous Matlab et regroupées sous le nom ProDIGE. L'exploitation par le laboratoire de protéomique de bioMérieux du workflow IDADIGE a été utilisée en routine et a permis la découverte de marqueurs protéiques du cancer colorectal qui doivent maintenant être validés biologiquement.
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Dabo, Issa-Mbenard. « Applications de la théorie des matrices aléatoires en grandes dimensions et des probabilités libres en apprentissage statistique par réseaux de neurones ». Electronic Thesis or Diss., Bordeaux, 2025. http://www.theses.fr/2025BORD0021.
Texte intégralRésumé :
Le fonctionnement des algorithmes d’apprentissage automatique repose grandement sur la structure des données qu’ils doivent utiliser. La majorité des travaux de recherche en apprentissage automatique se concentre sur l’étude de données homogènes, souvent modélisées par des variables aléatoires indépendantes et identiquement distribuées. Pourtant, les données apparaissant en pratique sont souvent hétérogènes. Nous proposons dans cette thèse de considérer des données hétérogènes en les dotant d’un profil de variance. Cette notion, issue de la théorie des matrices aléatoires, nous permet notamment d’étudier des données issues de modèles de mélanges. Nous nous intéressons plus particulièrement à la problématique de la régression ridge à travers deux modèles : la régression ridge linéaire (linear ridge model) et la régression ridge à caractéristiques aléatoires (random feature ridge model). Nous étudions dans cette thèse la performance de ces deux modèles dans le cadre de la grande dimension, c’est-à-dire lorsque la taille de l’échantillon d’entraînement et la dimension des données tendent vers l’infini avec des vitesses comparables. Dans cet objectif, nous proposons des équivalents asymptotiques de l’erreur d’entraînement et de l’erreur de test relatives aux modèles d’intérêt. L’obtention de ces équivalents repose grandement sur l’étude spectrale issue de la théorie des matrices aléatoires, des probabilités libres et de la théorie des trafics. En effet, la mesure de la performance de nombreux modèles d’apprentissage dépend de la distribution des valeurs propres de matrices aléatoires. De plus, ces résultats nous ont permis d’observer des phénomènes spécifiques à la grande dimension, comme le phénomène de la double descente. Notre étude théorique s’accompagne d’expériences numériques illustrant la précision des équivalents asymptotiques que nous fournissonsThe functioning of machine learning algorithms relies heavily on the structure of the data they are given to study. Most research work in machine learning focuses on the study of homogeneous data, often modeled by independent and identically distributed random variables. However, data encountered in practice are often heterogeneous. In this thesis, we propose to consider heterogeneous data by endowing them with a variance profile. This notion, derived from random matrix theory, allows us in particular to study data arising from mixture models. We are particularly interested in the problem of ridge regression through two models: the linear ridge model and the random feature ridge model. In this thesis, we study the performance of these two models in the high-dimensional regime, i.e., when the size of the training sample and the dimension of the data tend to infinity at comparable rates. To this end, we propose asymptotic equivalents for the training error and the test error associated with the models of interest. The derivation of these equivalents relies heavily on spectral analysis from random matrix theory, free probability theory, and traffic theory. Indeed, the performance measurement of many learning models depends on the distribution of the eigenvalues of random matrices. Moreover, these results enabled us to observe phenomena specific to the high-dimensional regime, such as the double descent phenomenon. Our theoretical study is accompanied by numerical experiments illustrating the accuracy of the asymptotic equivalents we provide
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Wells, Patrick Julian. « The rate of profit as a random variable ». Thesis, Open University, 2007. http://oro.open.ac.uk/22347/.
Texte intégralRésumé :
This thesis is a systematic attempt to investigate two conjectures about the distribution of company rates of profit: that it should be log-normal (Gibrat 1931), and that it should be gamma distributed (Farjoun and Machover 1983). A large set of company accounts data is analysed, and partial support found for Gibrat and for a generalised version of Farjoun and Machover. The analysis includes a demonstration of different empirical distributions for different profit rate measures, a demonstration of power law tails in all measures of the profit rate, and a demonstration of size effects (differences in tail weights) in financial ratios. Annual variation in the overall skewness and kurtosis of profit rate distributions is shown to be dominated by variation in the power law tails. L-moments, a recent innovation in robust methods to deal with extreme values, are used in conjunction with a size-weighted sampling scheme to identify possible models for distributions of the profit rate at the capital level. Farjoun and Machover derive their hypothesis from a particular conception of the process of capitalist competition. A rival conception, that of Glick (1985), is tested using company accounts data and shown to be vulnerable to criticism concerning the scope of its data set, the test statistic employed, and its choice of profit rate measure. More fundamentally, it is also dependent on doubtful premises about the within-industry distribution of profit rates, as L-moment analysis demonstrates.
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HAUDOT, STEPHANE. « Contribution a l'etude des caracteristiques aerodynamiques d'un profil a polaire variable ». Aix-Marseille 2, 1995. http://www.theses.fr/1995AIX22067.
Texte intégralRésumé :
Dans le cadre d'une approche numerique, cette etude presente les caracteristiques aerodynamiques et geometriques d'un profil d'aile susceptible de se deformer en fonction du champ de vitesse infinie amont ; l'objectif final etant d'induire des variations significatives de portance et de trainee. La configuration retenue est constituee d'un profil naca traverse par un canal horizontal (deux elements). L'etude est realisee a partir du code de calcul en mecanique des fluides phoenics (methode des volumes finis et schema hybrid) et dans le cadre d'un ecoulement turbulent (modele k-e). Plusieurs types de deplacements sont consideres: une reduction ou une augmentation de la section du canal et une rotation de l'un des elements. Les resultats obtenus revelent que seul un mouvement de rotation conduit a des variations significatives de portance et de trainee: dans l'intervalle considere, une reduction de dix pourcents est obtenue pour le cx et le cz. Une etude experimentale devant etre realisee ulterieurement, une simulation numerique de l'ensemble veine d'essais profil complet a egalement ete realisee ; l'objectif etait d'optimiser la geometrie de l'ensemble veine d'essais profil complet afin de conserver qualitativement les performances aerodynamiques du profil en milieu non-confine
Livres sur le sujet "Profil de variance"
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Fraser, D. A. S. Adjustments to profile likelihood. Toronto : University of Toronto, Dept. of Statistics, 1988.
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Engle, R. F. Valuation of variance forecasts with simulated option markets. Cambridge, MA : National Bureau of Economic Research, 1990.
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Williamson, Gordon K. All about annuities : Safe investment havens for high-profit returns. New York : J. Wiley, 1993.
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(Firm), Elsevier Advanced Technology, dir. Profile of the European motors and drives industry : Market forecasts to 1999. Oxford : Elsevier Advanced Technology, 1994.
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Board, Financial Accounting Standards. Accounting for transfers of assets in which a not-for-profit organizationis granted variance power : An interpretation of FASB Statement no.116. Norwalk, Conn : FASB, 1996.
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Raskalinos, Valeriya. Pedagogical skills. ru : INFRA-M Academic Publishing LLC., 2024. http://dx.doi.org/10.12737/1865677.
Texte intégralRésumé :
The educational manual presents educational materials on the general professional discipline “Pedagogical Excellence” (a variable part of the training program for mid-level specialists). Aimed at developing students' professional individuality through the integration of experience, theoretical knowledge and practical skills. Meets the requirements of the latest generation of federal state educational standards for secondary education. For students of secondary specialized educational institutions with a pedagogical profile, as well as teachers of pedagogical colleges working with students studying in the specialty “Preschool Education”.
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Shishkin, Andrey. Introduction to the axiomatic theory of elementary functions. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1209581.
Texte intégralRésumé :
Contains an exposition of the basic concepts and theorems of the axiomatic theory of the basic elementary functions of real and complex variables. The textbook is written on the basis of lectures given by the author for a number of years at the Armavir State Pedagogical University, at the Slavyansk-on-Kuban State Pedagogical Institute and at the branch of the Kuban State University in Slavyansk-on-Kuban. It is intended for students of natural-mathematical profiles of preparation of the direction "Pedagogical education". It can be used in the study of mathematical analysis, the theory of functions of a real variable, the theory of functions of a complex variable, etc.
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Kuz'mina, Tat'yana. Self-awareness and personal adaptive potential in normal and impaired development. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1086621.
Texte intégralRésumé :
The monograph presents the generalized results of the author's scientific activity related to the diagnosis and phenomenological description of the state of self-consciousness and the Self-concept of persons with developmental disorders, in particular with mild mental retardation. The variants of self-awareness diagnostics and a comprehensive assessment of the personal adaptive potential of subjects of different ages with intellectual disabilities are presented and methodologically justified. The presented methods allow us to form an individual adaptive profile based on a quantitative assessment of qualitative indicators of adaptability/maladaptivity. The content aspects of the formation of the antisocial potential of a person with mild mental retardation, in particular, the problems of suggestibility, indoctrination and the participation of persons with intellectual disabilities in criminal communities, are separately identified.
It will be useful for students, postgraduates, researchers and practitioners in the field of pedagogy, psychology, law.
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Sosa-Rubi, Sandra G. Heterogeneous impact of the "seguro popular" program on the utilization of obstetrical services in mexico, 2001-2006 : A multinomial probit model with a discrete endogenous variable. Cambridge, MA : National Bureau of Economic Research, 2007.
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Lemeshko, Boris, et Irina Veretel'nikova. Criteria for testing hypotheses about randomness and the absence of a trend. Application Guide. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1587437.
Texte intégralRésumé :
The monograph discusses the application of statistical criteria aimed at testing hypotheses about the absence of a trend in the analyzed samples. The rejection of such a hypothesis gives grounds to consider the analyzed data as samples of independent equally distributed random variables. We consider a set of special criteria aimed at testing such hypotheses, as well as a set of criteria for the uniformity of laws, the uniformity of averages and the uniformity of variances, which can also be used for these purposes. The disadvantages and advantages of various criteria are emphasized, the application of criteria in conditions of violation of standard assumptions is considered. Estimates of the power of the criteria are given, which allows you to navigate when choosing the most preferred criteria. Following the recommendations will ensure the correctness and increase the validity of statistical conclusions when analyzing data.
It is intended for specialists who are interested in the application of statistical methods for the analysis of various aspects and trends of the surrounding reality and who are in contact with the processing of experimental results, the need for data analysis in their activities. It will be useful for engineers, researchers, specialists of various profiles (doctors, biologists, sociologists, economists, etc.) who face the need for statistical analysis of experimental results in their activities. It will also be useful for university teachers, graduate students and students.
Chapitres de livres sur le sujet "Profil de variance"
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Osaki, Yoji. « Nonradial Modes in Line-Profile Variable Stars ». Dans Seismology of the Sun and the Distant Stars, 453–63. Dordrecht : Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4608-8_47.
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van Ruitenbeek, Floris, Boi Okken et Wesley Roozing. « Variable Stiffness Mechanism Using a Cam Profile ». Dans Springer Proceedings in Advanced Robotics, 76–80. Cham : Springer Nature Switzerland, 2024. https://doi.org/10.1007/978-3-031-76424-0_14.
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Zerbi, Filippo M. « Simultaneous Light Curve, Color Curve and Line Profile Fitting for Pulsating Stars ». Dans Variable Stars as Essential Astrophysical Tools, 293–312. Dordrecht : Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-011-4299-1_11.
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Silva-Corvalán, Carmen. « The social profile of a syntactico-semantic variable ». Dans Diversity and Diachrony, 279. Amsterdam : John Benjamins Publishing Company, 1986. http://dx.doi.org/10.1075/cilt.53.24sil.
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Mathai, Arak M., Serge B. Provost et Hans J. Haubold. « Profile Analysis and Growth Curves ». Dans Multivariate Statistical Analysis in the Real and Complex Domains, 813–44. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-95864-0_14.
Texte intégralRésumé :
AbstractWe will utilize the same notations as in the previous chapters. Lower-case letters x, y, … will denote real scalar variables, whether mathematical or random. Capital letters X, Y, … will be used to denote real matrix-variate mathematical or random variables, whether square or rectangular matrices are involved. A tilde will be placed on top of letters such as $$\tilde {x},\tilde {y},\tilde {X},\tilde {Y}$$ x ~ , y ~ , X ~ , Y ~ to denote variables in the complex domain. Constant matrices will for instance be denoted by A, B, C. A tilde will not be used on constant matrices unless the point is to be stressed that the matrix is in the complex domain.
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Brusov, Peter, Tatiana Filatova et Natali Orekhova. « BFO Theory with Variable Profit in Case of Advance Payments of Tax on Profit ». Dans The Brusov–Filatova–Orekhova Theory of Capital Structure, 291–316. Cham : Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27929-4_15.
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Tribedi, Apurba. « Variable Modulus of Subgrade Reaction - Settlement Profile Convergence Method ». Dans Advanced Research on Shallow Foundations, 162–84. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01923-5_13.
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Wu, Hanji, Yongsheng Xu et Zhen Zhong. « Single-Profile Choice Functions and Variable Societies : Characterizing Approval Voting ». Dans Studies in Choice and Welfare, 143–48. Berlin, Heidelberg : Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-46439-7_9.
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Sutrisno. « Financing Scheme and Determinant Factors ». Dans Proceedings of the 19th International Symposium on Management (INSYMA 2022), 18–27. Dordrecht : Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-008-4_4.
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AbstractThis study aims to examine the factors that influence the financing scheme of Islamic Rural Banks (IRBs) in Indonesia. The financing scheme consists of profit margin financing (PMF) and profit-sharing financing (PSF). Factors thought to influence the financing scheme are non-performing financing (NPF), financing to deposit ratio (FDR), capital adequacy ratio (CAR), return on assets (ROA), operating to income ratio (OEIR), and company size (Size). The population in this study was 163 IRBs in Indonesia with a sample of 100 IRBs. The observation period was 4 years, with quarterly data. Hypothesis testing applied multiple regression. The results show that the factors influencing the financing scheme between PMF and PSF are the same, namely, NPF and Size have a significant negative effect, while FDR, CAR, ROA and OEIR have no effect. One variable is OEIR; if the significance level is 10%, then OEIR has a significant and negative effect on the profit-sharing financing scheme, but the profit-margin financing scheme has no effect.
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Richter, Michael, et Ariel Rubinstein. « 2. The Permissible and the Forbidden ». Dans No Prices No Games !, 37–64. 2e éd. Cambridge, UK : Open Book Publishers, 2024. http://dx.doi.org/10.11647/obp.0438.02.
Texte intégralRésumé :
Following Richter and Rubinstein (2020), we analyze an equilibrium concept based upon social norms: the Y-equilibrium. A Y-equilibrium is a set of permissible alternatives and a profile of choices, one for each agent, such that: (i) each agent's choice is optimal from among the permissible alternatives; (ii) the profile of choices is feasible; and (iii) the set of permissible alternatives is maximal in the sense that there is no superset of permissible alternatives from which a profile satisfying (i) and (ii) can be found. By this definition, two forces make a permissible set unstable: The first modifies the permissible set in the case that the profile of (intended) choices is not feasible, while the second loosens restrictions on the permissible set as long as a new profile of optimal choices is feasible. We also consider a variant of this concept where we require that the permissible set is convex. We study the Y-equilibria of a variety of examples and prove existence theorems, “welfare” theorems and a structure theorem when the set of alternatives is Euclidean.
Actes de conférences sur le sujet "Profil de variance"
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Mohseni, Arman, Erik Goldhahn, Rene´ A. Van den Braembussche et Joerg R. Seume. « Novel IGV Designs for Centrifugal Compressors and Their Interaction With the Impeller ». Dans ASME Turbo Expo 2010 : Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23048.
Texte intégralRésumé :
In centrifugal compressors, variable inlet guide vanes (IGVs) are used to control the mass flow rate with negligible change in pressure ratio and shaft speed. The efficient operation of IGVs is limited to the range of aerodynamic stability of their vane profiles. Thin symmetric profiles, which are usually used, tend to exhibit flow separation already at low setting angles, resulting in a rapid decrease of the global efficiency. Three different guide vane profiles including a symmetric reference, a two-piece tandem profile with variable angle, and an s-cambered, together with two auxiliary profiles were considered. These variants were numerically and experimentally investigated at different setting angles, covering negative and positive inlet swirl and at different operating points. The results show that tandem and s-cambered vanes have superior aerodynamic performance in comparison with the symmetric reference profile and extend the operating range of the compressor over which the efficiency remains high. The tandem profile shows better aerodynamic performance than the s-cambered profile at negative inlet swirl, while the asymmetric s-cambered profile offers an extended range of high efficiency at positive preswirl. Considering manufacturing requirements and cost, the s-cambered profile is preferred for applications with positive preswirl.
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Rejivas, V. A., A. Praveen et T. Ajitha. « Determination of Collinearity Developed in the CMB Model with the Concepts of Multi Linear Regression Analysis ». Dans 2nd International Conference on Modern Trends in Engineering Technology and Management. AIJR Publisher, 2023. http://dx.doi.org/10.21467/proceedings.160.12.
Texte intégralRésumé :
The Chemical Mass Balance model (CMB) gives an accurate source apportionment for the contribution of the sources with the input data of the source profile and receptor data collected. The source profiles for different sources should have a unique and specific species characterization for getting accurate source apportionment results. But due to the mixing of sources, the species characterization source profile may not have unique and specific species characterization due to the non-availability of the exact representation of particular sources and culminates collinearity of species during the CMB analysis. It leads to negative source apportionment results in the CMB analysis. Multi Linear Regression analysis that addresses in the study can effectively be used to identify the collinearity contributing sources. The Multi Linear Regression parameters such as tolerance, variance inflation factor (VIF), condition index, and variance decomposition proportions developed with the source profile variables (source profiles for soil, paved road dust, biomass, and traffic) are used for identifying the collinear sources. The tolerance value for the soil and paved road dust sources are obtained as 0.001 each and the variance inflation factor (VIF) for both are obtained as 204.2 and 208.8 respectively. It indicates the collinearity between soil and paved road dust. Collinearity diagnostics of the regression equations showed that the condition index and the variance decomposition proportion obtained for the soil and paved road dust were greater than 30 (104.09) and 90% (100%) respectively. Therefore, the presence of strong collinearity between soil and paved road dust can be understood.
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Rasheed, Haroon, Jinhu Li, Yu Liu et Caisheng Hou. « CONSTRUCTION AND PERFORMANCE RESEARCH OF VARIABLE CROSS-SECTION SCROLL PROFILE USING THE BASE CIRCLE INVOLUTE ». Dans Topics In Chemical & Material Engineering (TCME). Volkson Press, 2023. http://dx.doi.org/10.26480/smmp.01.2023.59.65.
Texte intégralRésumé :
The use of variable cross-section scroll profile is one of the effective ways to improve the performance of the scroll compressor. However, the existing variable cross-section scroll profiles have many disadvantages, such as difficult processing and unstable performance. For this reason, this paper adopted the base circle involute with stable performance and easy processing characteristics to construct a new type of variable cross-section scroll profile, and established the basic geometric theory of the profile. At the same time, two important indexes of volumetric performance, namely compression ratio and radial leakage line length, and a key index of mechanical performance, that is axial gas force, were introduced to evaluate its performance quantitatively. The results show that under the same basic parameters, compared with the equal cross-section profile formed by a single base circle involute as well as the traditional variable cross-section profile formed by the base circle involute, higher-order curve and base circle involute or circular arc, the volumetric performance and mechanical performance of the newly constructed variable cross-section profile are more advantageous, the compression ratio increased by 28.62%, 16.51% and 7.58% respectively; The length of radial leakage line is shortened by 26.56%, 16.37% and 14.23% respectively; The axial gas force is also significantly reduced, especially for the profile without the introduction of higher-order curve, the change range of the axial gas force is obviously smaller. The research broadens the design concept of the scroll profile, enriches the types of existing variable cross-section scroll profiles, and provides a certain theoretical basis for improving the performances of the scroll compressor.
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Tang, S. C. « An isolated low-profile low-power converter ». Dans 8th International Conference on Power Electronics and Variable Speed Drives. IEE, 2000. http://dx.doi.org/10.1049/cp:20000270.
Texte intégral
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Jeans, Gus, Liam Harrington-Missin, Andrew Watson et Jon Upton. « The Use of Empirical Orthogonal Functions for Deriving Response Based Extreme Current Profiles ». Dans ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83052.
Texte intégralRésumé :
Coherent extreme current profiles are derived to reduce the over-conservatism associated with the traditional assumption that extreme currents occur at all depths through the water column simultaneously. Empirical Orthogonal Function (EOF) analysis has proven effective for derivation of coherent extreme current profiles in regions where it effectively captures the dominant characteristics of the flow regime. This is despite the questionable suitability of EOF for Current Profile Characterisation, which reduces a large current profile data set into a much smaller set of profiles for riser fatigue studies. EOF Mode 1 and 2 are used to represent six years of in-situ current profiles accounting for 97.75% of the original variance. With the assumption that depth integrated speed squared is proportional to drag on a simple riser, three sets of extreme current profiles were derived. A) Profiles associated with extreme near surface current speeds, B) Profiles associated with extreme mid-depth current speeds and C) Profiles associated with extreme drag on a riser.
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Dierks, Ludwig, et Sven Seuken. « The Competitive Effects of Variance-based Pricing ». Dans Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}. California : International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/ijcai.2020/51.
Texte intégralRésumé :
In many markets, like electricity or cloud computing markets, providers incur large costs for keeping sufficient capacity in reserve to accommodate demand fluctuations of a mostly fixed user base. These costs are significantly affected by the unpredictability of the users' demand. Nevertheless, standard mechanisms charge fixed per-unit prices that do not depend on the variability of the users' demand. In this paper, we study a variance-based pricing rule in a two-provider market setting and perform a game-theoretic analysis of the resulting competitive effects. We show that an innovative provider who employs variance-based pricing can choose a pricing strategy that guarantees himself a higher profit than using fixed per-unit prices for any individually rational response of a provider playing a fixed pricing strategy. We then characterize all equilibria for the setting where both providers use variance-based pricing strategies. We show that, in equilibrium, the providers' profits may increase or decrease, depending on their cost functions. However, social welfare always weakly increases.
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Buschkoetter, Kyle, et Ashok Midha. « Design of a Compliant Mechanism to Generate an Arbitrary Nonlinear Force-Deflection Profile ». Dans ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86360.
Texte intégralRésumé :
This paper presents a compliant mechanism that can generate a wide range of force-deflection profiles. This partially compliant mechanism is comprised of a wedge cam with a compliant follower. The designer specifies the material and geometric properties of the compliant segment, as well as a desired force-deflection profile. A cam surface is then synthesized that helps generate this profile. The synthesis method is validated experimentally with the help of two case studies. Some possible areas of application include robotics, variable stiffness actuators, electrical connectors, design for automotive crashworthiness, and variable resistance exercise equipment.
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Emiliani, Gabriele, et Angela Piegari. « Optical coatings with radially controlled reflection intensity and phase shift ». Dans OSA Annual Meeting. Washington, D.C. : Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.thnn1.
Texte intégralRésumé :
An interesting application of optical coatings in the laser field requires cavity mirrors with a particular reflectance profile (i.e., a Gaussian profile) along the coating radius. However, these devices generally introduce a phase distortion in the wave front of the laser beam. Real improvement in laser performance depends on controlling both the reflection intensity and phase profile. Traditional design procedures and thin-film deposition techniques are aimed at producing coatings with defined reflectance values at different wavelengths but uniform reflectance on the coating surface. In this work, the reflection and transmission intensity and phase at a single wavelength are examined, and a suitable design method for obtaining desired radial profiles is proposed. The phase front is generally required to be flat along the radius while, at the same time, the reflection intensity either decreases continuously from the coating center to the outside or has a jump at a particular radius value. Such performances are obtained with thin-film multilayer coatings in which one of the layers has a profiled thickness. This radially variable thickness is achieved by the aid of a properly shaped mask in a sputtering deposition apparatus. Coatings for Nd:YAG and CO2 lasers are examined.
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Dordova, Lucie, et Otakar Wilfert. « Distribution of optical intensity relative variance in laser beam profile ». Dans 2010 15th Conference on Microwave Techniques (COMITE 2010). IEEE, 2010. http://dx.doi.org/10.1109/comite.2010.5481540.
Texte intégral
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Kavaya, Michael J., et Edward C. Russell. « Monte Carlo Simulations of Coherent DIAL Water Vapor Measurement Performance ». Dans Coherent Laser Radar. Washington, D.C. : Optica Publishing Group, 1987. http://dx.doi.org/10.1364/clr.1987.tha1.
Texte intégralRésumé :
Previous DIAL performance simulations have employed "expected value" analytic expressions which relate the normalized variance of the measured quantity (e.g, water vapor density) to several variances, covariances, and values of other measurement parameters, such as received power and number of shot-pairs [1-4]. The calculated variance (error) vs height actually represents the expected value or ensemble average error that would be obtained through numerous DIAL measurements of N shot—pairs each, on a microscopically frozen atmosphere, However, atmospheric parameters vary both temporally and spatially in complex ways. A Monte Carlo DIAL computer simulation was developed to allow observation of relative magnitudes and interrelationships of various instrument and atmospheric effects. These include speckle; refractive turbulence; field curvature mismatch; transmitter and receiver diameters; wind velocity and/or lidar motion; pulse repetition frequency (PRE); time delay between pulses of one pulse—pair; total measurement time; pulse—pair averaging; pulse temporal profile; fluctuations in atmospheric backscatter and absorption; fluctuations in the densities of atmospheric constituents; and range smoothing.
Rapports d'organisations sur le sujet "Profil de variance"
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Phelan, Thomas M. On the Optimality of Differential Asset Taxation. Federal Reserve Bank of Cleveland, février 2025. https://doi.org/10.26509/frbc-wp-201917r2.
Texte intégralRésumé :
In this paper I study the optimality of differential asset taxation in an environment with entrepreneurs and workers in which output is stochastic and entrepreneurs can misreport profits and abscond with capital. I show that a stationary efficient allocation may be implemented as an equilibrium with endogenous collateral constraints, transfers to newborns, and linear taxes on profits, investment, and interest. Further, these taxes differ from one another and serve distinct purposes. The profits tax shares risk and depends solely on the severity of the misreporting friction, while the remaining instruments determine the efficient mean and variance of entrepreneurs' consumption growth.
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Tran, Thi Hong Van, Bartłomiej Woś, Tomasz Wanic, Marcin Pietrzykowski et Agnieszka Józefowska. Impact of charcoal and tree species on forest soil recovery after fire disturbance Dataset. Publishing House of the University of Agriculture in Krakow, 2025. https://doi.org/10.15576/repourk/2025.1.1.
Texte intégralRésumé :
This dataset examines the impact of charcoal and tree species on forest soil recovery post-fire, encompassing soil profile characteristics, particle size distribution (granulometry), and chemical properties. It includes measurements from eight variants, considering four tree species and two land preparation methods for regeneration: with and without charcoal removal. The methodology and study location are described in the publication.
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Ultrasound Measurement of Shear Wave Speed for Estimation Liver Fibrosis, Clinically Feasible Profile. Chair David Fetzer, Stephen McAleavey et Stephen Rosenzweig. Radiological Society of North America (RSNA) / Quantitative Imaging Biomarkers Alliance (QIBA), janvier 2024. http://dx.doi.org/10.1148/qiba/20240115.
Texte intégralRésumé :
The goal of a QIBA Profile is to help achieve a useful level of performance for a given biomarker. Profile development is an evolutionary, phased process; this Profile is in the “Clinically Feasible” (formerly “Technically Confirmed") stage. The performance claims represent expert consensus and will be empirically demonstrated at a subsequent stage. Several sites have performed the profile, found it to be practical, and expect it to achieve the claimed performance. Users of this Profile are encouraged to refer to the following site to understand the document’s context: http://qibawiki.rsna.org/index.php/QIBA_Profile_Stages. The Claim (Section 2) describes the biomarker performance. The Activities (Section 3) contribute to generating the biomarker. Requirements are placed on the Actors that participate in those activities as necessary to achieve the Claim. Assessment Procedures (Section 4) for evaluating specific requirements are defined as needed. Conformance (Section 5) regroups Section 3 requirements by Actor to conveniently check Conformance. This QIBA Profile (Ultrasound Measurement of Shear Wave Speed for Estimation of Liver Fibrosis) addresses estimation of liver fibrosis, which is often used to determine when and how to treat patients with diffuse liver disease, and also monitor progression or response to treatment. It places requirements on ultrasound scanners (acquisition devices), Scanner Manufacturer/Vendor, Technologists/Sonographers, QA (Quality Assurance) Manager, Radiologists, and Image Analysis Tools involved in pre-delivery steps, scanner installation, periodic QA procedures, subject selection and handling, SWS image acquisition, image QA, and image analysis. The requirements are focused on achieving sufficient accuracy and avoiding unnecessary variability of the estimation of liver fibrosis. Estimates of liver fibrosis are based on a measurement of shear wave speed (SWS) in the tissue using ultrasound, which in turn is based on the stiffness of the liver tissue. The clinical performance target is to achieve SWS measurements with a bias of the mean value of ≤ 5% and an overall coefficient of variation (SD/mean) of ≤ 5%. The standard against which to measure bias has not yet been fully defined, so currently there is no bias claim. At the present time, bias is determined by comparison to the measured SWS and stiffness using a Verasonics ultrasound system in a calibrated QIBA SWS phantom. Currently bias and precision depend on the magnitude of measured SWS (as determined in phantom studies) so bias and variance claims are given for three ranges of measured SWS values. Also, bias and precision depend on the conditions under which the measurements are made. Bias and precision claims are therefore also given for various measurement conditions. This document is intended to help clinicians basing decisions on this biomarker, imaging staff generating this biomarker, vendor staff developing related products, purchasers of such products, and investigators designing trials with imaging endpoints. Note that this document only states requirements to achieve the claim, not “requirements on standard of care.” Conformance to this Profile is secondary to properly caring for the patient. QIBA Profiles addressing other imaging biomarkers using CT, MRI, PET and Ultrasound can be found at https://qibawiki.rsna.org/index.php/Main_Page
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Azar, Pablo, Adrian Casillas et Maryam Farboodi. Information and Market Power in DeFi Intermediation. Federal Reserve Bank of New York, mai 2024. http://dx.doi.org/10.59576/sr.1102.
Texte intégralRésumé :
The decentralized nature of blockchain markets has given rise to a complex and highly heterogeneous market structure, gaining increasing importance as traditional and decentralized (DeFi) finance become more interconnected. This paper introduces the DeFi intermediation chain and provides theoretical and empirical evidence for private information as a key determinant of intermediation rents. We propose a repeated bargaining model that predicts that profit share of Ethereum market participants is positively correlated with their private information, and employ a novel instrumental variable approach to show that a 1 percent increase in the value of intermediaries’ private information leads to a 1.4 percent increase in their profit share.
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Ziegler, Nancy, Nicholas Webb, Adrian Chappell et Sandra LeGrand. Scale invariance of albedo-based wind friction velocity. Engineer Research and Development Center (U.S.), mai 2021. http://dx.doi.org/10.21079/11681/40499.
Texte intégralRésumé :
Obtaining reliable estimates of aerodynamic roughness is necessary to interpret and accurately predict aeolian sediment transport dynamics. However, inherent uncertainties in field measurements and models of surface aerodynamic properties continue to undermine aeolian research, monitoring, and dust modeling. A new relation between aerodynamic shelter and land surface shadow has been established at the wind tunnel scale, enabling the potential for estimates of wind erosion and dust emission to be obtained across scales from albedo data. Here, we compare estimates of wind friction velocity (u*) derived from traditional methods (wind speed profiles) with those derived from the albedo model at two separate scales using bare soil patch (via net radiometers) and landscape (via MODIS 500 m) datasets. Results show that profile-derived estimates of u* are highly variable in anisotropic surface roughness due to changes in wind direction and fetch. Wind speed profiles poorly estimate soil surface (bed) wind friction velocities necessary for aeolian sediment transport research and modeling. Albedo-based estimates of u* at both scales have small variability because the estimate is integrated over a defined, fixed area and resolves the partition of wind momentum be-tween roughness elements and the soil surface. We demonstrate that the wind tunnel-based calibration of albedo for predicting wind friction velocities at the soil surface (us*) is applicable across scales. The albedo-based approach enables consistent and reliable drag partition correction across scales for model and field estimates of us* necessary for wind erosion and dust emission modeling.
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MR (Diffusion-Weighted Imaging (DWI) of the Apparent Diffusion Coefficient (ADC), Clinically Feasible Profile. Chair Michael Boss, Dariya Malyarenko et Daniel Margolis. Radiological Society of North America (RSNA) / Quantitative Imaging Biomarkers Alliance (QIBA), décembre 2022. http://dx.doi.org/10.1148/qiba/20221215.
Texte intégralRésumé :
The goal of a QIBA Profile is to help achieve a useful level of performance for a given biomarker. The Claim (Section 2) describes the biomarker performance and is derived from the body of scientific literature meeting specific requirements, in particular test-retest studies. The Activities (Section 3) contribute to generating the biomarker. Requirements are placed on the Actors that participate in those activities as necessary to achieve the Claim. Assessment Procedures (Section 4) for evaluating specific requirements are defined as needed to ensure acceptable performance. Diffusion-Weighted Imaging (DWI) and the Apparent Diffusion Coefficient (ADC) are being used clinically as qualitative (DWI) and quantitative (ADC) indicators of disease presence, progression or response to treatment. Use of ADC as a robust quantitative biomarker with finite confidence intervals places additional requirements on Sites, Acquisition Devices and Protocols, Field Engineers, Scanner Operators (MR Technologists, Radiologists, Physicists and other Scientists), Image Analysts, Reconstruction Software and Image Analysis Tools. Additionally, due to the intrinsic dependence of measured ADC values on biophysical tissue properties, both the Profile Claims and the associated scan protocols (Section 3.6.2) are organ-specific. All of these are considered Actors involved in Activities of Acquisition Device Pre-delivery and Installation, Subject Handling, Image Data Acquisition, Reconstruction, Registration, ADC map generation, Quality Assurance (QA), Distribution, Analysis, and Interpretation. The requirements addressed in this Profile are focused on achieving ADC values with minimal systematic bias and measurement variability. DISCLAIMER: Technical performance of the MRI system can be assessed using a phantom having known diffusion properties, such as the QIBA DWI phantom. The clinical performance target is to achieve a 95% confidence interval for measurement of ADC with a variable precision depending on the organ being imaged and assuming adequate technical performance requirements are met. While in vivo DWI/ADC measurements have been performed throughout the human body, this Profile focused on four organ systems, namely brain, liver, prostate, and breast as having high clinical utilization of ADC with a sufficient level of statistical evidence to support the Profile Claims derived from the current peer-reviewed literature. In due time, new DWI technologies with proven greater performance levels, as well as more organ systems will be incorporated in future Profiles. This document is intended to help a variety of users: clinicians using this biomarker to aid patient management; imaging staff generating this biomarker; MRI system architects developing related products; purchasers of such products; and investigators designing clinical trials utilizing quantitative diffusion-based imaging endpoints. Note that this document only states requirements specific to DWI to achieve the claim, not requirements that pertain to clinical standard of care. Conforming to this Profile is secondary to proper patient care.
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SPECT Dopamine Transporters, Consensus QIBA Profile. Chair John Dickson et John Seibyl. Radiological Society of North America (RSNA)/Quantitative Imaging Biomarkers Alliance (QIBA), octobre 2019. https://doi.org/10.1148/qiba/20191015.
Texte intégralRésumé :
Parkinsonism is a major health problem. Distinguishing neurodegenerative causes of parkinsonism from non-degenerative movement disorders that can mimic Parkinson’s disease (PD) has important implications for prognosis and clinical management. The goal of this QIBA Profile is to optimize the performance of Iodine-123 (123I) ioflupane single photon emission computed tomography (SPECT) for quantifying the concentration of regional cerebral dopamine transporters (DaT) in patients with movement disorders. The Claim (Section 2): This profile claims that conformance with its specifications will provide test-retest technical variance of less than 15% COV. In clinical use this might permit the ability to distinguish true biological change from measurement noise in clinical trials of participants who will be studied cross— sectionally, to aid accurate cohort recruitment and longitudinally with 123I-ioflupane. The claim is founded on observations that neurodegenerative disorders, such as idiopathic PD and Diffuse Lewy Body Dementia (DLBD), are associated with dopaminergic neuronal degeneration, which can be particularly pronounced in the substantia nigra. The degeneration of the axonal projections from the substania nigra to the basal ganglia is manifested as a loss of DaT activity. In most clinical imaging contexts where the question is about a neurodegenerative disorder, the loss is first observed in the most posterior aspect of the putamen, and then seems to march anteriorly, with left and right sides showing asymmetric changes. As a result, quantifying DaT can distinguish normal and abnormal states. The Activities (Section 3) describe what needs to be done to make measurements that reliably distinguish patients from controls with confidence. Requirements are placed on the Actors who participate in those activities as necessary to achieve the Claim. The Assessment Procedures (Section 4) for evaluating specific requirements are defined as needed. This QIBA Profile, “Quantifying Dopamine Transporters with 123Iodine Labeled Ioflupane in Neurodegenerative Disease”, addresses quantitative SPECT imaging, which is often used as a diagnostic, as well as a longitudinal biomarker of disease progression or response to treatment. It places requirements on Acquisition Devices, Technologists, Radiologists, Reconstruction Software and Image Analysis Tools involved in Subject Handling, Image Data Acquisition, Image Data Reconstruction, Image QA and Image Analysis. The requirements are focused on achieving sufficient accuracy and avoiding technical variability of the DaT measurements to distinguish neurodegenerative causes of parkinsonism from non-degenerative causes. The clinical performance target is to achieve a 95% confidence interval for the striatal binding ratio with both a reproducibility and a repeatability of +/- 15%. This document is intended to help clinicians basing decisions on this biomarker, imaging staff generating this biomarker, vendor staff developing related products, purchasers of such products, and investigators designing trials with imaging endpoints. Note that this document only states requirements to achieve the claim, not “requirements on standard of care”. Conformance to this Profile is secondary to properly caring for the patient. This QIBA Profile, and others like it addressing CT, MRI, PET and ultrasound can be found at www.qibawiki.rsna.org.
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99mTc SPECT-CT, Consensus QIBA Profile. Chair Yuni Dewaraja et Robert Miyaoka. Radiological Society of North America (RSNA)/Quantitative Imaging Biomarkers Alliance (QIBA), octobre 2019. https://doi.org/10.1148/qiba/20191021.
Texte intégralRésumé :
The quantification of 99mTc labeled biomarkers can add unique value in many different settings, ranging from clinical trials of investigation new drugs to the treatment of individual patients with marketed therapeutics. For example, goals of precision medicine include using companion radiopharmaceutical diagnostics as just-in-time, predictive biomarkers for selecting patients to receive targeted treatments, customizing doses of internally administered radiotherapeutics, and assessing responses to treatment. This Profile describes quantitative outcome measures that represent proxies of target concentration or target mass in topographically specific volumes of interest (VOIs). These outcome measures are usually expressed as the percent injected dose (i.e., radioactivity) per mL of tissue (%ID/mL), a standard uptake value ratio (SUVr), or a target-to-background ratio (TBR). In this profile, targeting is not limited to any single mechanism of action. Targeting can be based on interaction with a cell surface protein, an intracellular complex after diffusion, protein-mediated transport, endocytosis, or mechanical trapping in a capillary bed, as in the case of transarterial administration of embolic microspheres. Regardless, the profile focuses on quantification in well-defined volumes of interest. Technetium-99m based dopamine transporter imaging agents, such as TRODAT, are nearly direct links with some aspects of the predecessor profile on 123I-ioflupane for neurodegenerative disorders. (See www.qibawiki.rsna.org ) Cancer is often a base case of convenience for new material in this profile, but the intent is to create methods that can be useful in other therapeutic areas where the diseases are characterized by spatially-limited anatomical volumes, such as lung segments, or multifocal aggregations of targets, such as white blood cell surface receptors on pulmonary nodules in patients with sarcoidosis. Neoplastic masses that can be measured with x-ray computed tomography (CT) or magnetic resonance imaging (MRI) are the starting point. However, the intent is to create a profile that can be extrapolated to diseases in other therapeutic areas that are also associated with focal, or multi-focal pathology, such as pulmonary granulomatous diseases of autoimmune or infectious etiology, non-oncological diseases of organs such as polycystic kidney disease, and the like. The criteria for measurability are based on the current resolution of most SPECT-CT systems in clinical practice, and are independent of criteria for measurability in other contexts. For this SPECT profile, conformance requires that a “small” VOI must be greater than 30 mL to be measurable. It is understood that much smaller VOIs can sometimes exhibit high conspicuity on SPECT, but these use cases are beyond the scope of this profile and will not be tested for conformance in this version. It is left to individual stakeholders to show the extent to which they can achieve conformance when measuring VOIs less than 30 mL. The detection of smaller changes during clinical trials of large groups can be achieved by referring to the QIBA companion guidance on powering trials. The Claims (Section 2) asserts that compliance with the specifications described in this Profile will produce cross sectional estimates of the concentration of radioactivity [kBq/mL] in a volume of interest (VOI) or a target-to-background ratio (TBR) within a defined confidence interval (CI), and distinguish true biological change from system variance (i.e., measurement error) in individual patients or clinical trials of many patients who will be studied longitudinally with 99mTc SPECT agents. Both claims are founded on observations that target density varies between patients with the same disease as well as within patients with multi-focal disease. The Activities (Section 3) describes the requirements that are placed on the Actors who need to achieve the Claim. Section 3 specifies what the actors must do in order to estimate the amount of radioactivity in a volume of interest, expressed in kBq/mL (ideal) or as a TBR (acceptable) within a 95% CI surrounding the true value. Measurands such as %ID/mL are targets for nonclinical studies in animal models that use terminal sacrifice to establish ground truth for imaging studies. TBRs can be precarious, as the assumptions that depend on the physiology of the background regions matching the volume of interest can be hard to accept sometimes. It is up to each individual stakeholder to qualify the background regions used in their own use case. This profile qualifies only a few in some very limited contexts as examples. The Assessment Procedures (Section 4) for evaluating specific requirements are defined as needed. The requirements are focused on achieving sufficient accuracy and avoiding unnecessary variability of the measurements. The clinical performance target is to achieve a 95% confidence interval for concentration in units of kBq/mL (kilobequerels per milliliter) or %ID/mL (percent injected dose per milliliter) or TBR with both a reproducibility and a repeatability of +/- 8% within a single individual under zero-biological-change conditions. This document is intended to help clinicians basing decisions on these biomarkers, imaging staffs generating measurements of these biomarkers, vendors who are developing related products, purchasers of such products, and investigators designing trials. Note that this document only states requirements to achieve the claims, not “requirements on standard of care” nor compliance with any particular protocol for treating participants in clinical trial settings. Conformance to this Profile is secondary to properly caring for patients or adhering to the requirements of a protocol. QIBA Profiles addressing other imaging biomarkers using CT, MRI, PET and Ultrasound can be found at www.qibawiki.rsna.org.
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Jamilov, Rustam, Hélène Rey et Ahmed Tahoun. The Anatomy of Cyber Risk. Institute for New Economic Thinking Working Paper Series, mai 2023. http://dx.doi.org/10.36687/inetwp206.
Texte intégralRésumé :
This paper employs computational linguistics to introduce a novel text-based measure of firm-level cyber risk exposure based on quarterly earnings conference calls of listed firms. Our quarterly measures are available for more than 13,000 firms from 85 countries over 2002-2021. We document that cyber risk exposure predicts cyber attacks, affects stock returns and profits, and is priced in the equity option market. The cost of option protection against price, variance, and tail risks is greater for more cyber-exposed firms. Cyber risks spill over across firms and persist at the sectoral level. The geography of cyber risk exposure is well approximated by a gravity model extended with cross-border portfolio flows. Back-of-the-envelope calculations suggest that the global cost of cyber risk is over $200 billion per year.
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Pineda-Mendez, Raul, Qiming Guo, Noshin Ahmad, Mario A. Romero et Andrew P. Tarko. Incorporating Time-Dependent Data for Proactive Safety Management. Purdue University, 2024. http://dx.doi.org/10.5703/1288284317700.
Texte intégralRésumé :
This study proposed a risk-based safety management framework to supplement the current crash-based safety management system. The proposed tool considers time-dependent factors (e.g., hourly traffic, speed features, weather conditions, signal controls) to help justify operational measures for safety improvements (e.g., variable message signs, variable speed limits, warnings). These selected temporal factors subsequently were included in the developed sequential logit models; and those models, applied hour by hour, were then used to estimate the crash probability and severity level. Two typical roadway elements, rural freeway segments and signalized intersections, were also included in the analysis. The obtained crash risk profiles can be used to predict the expected number of crashes in periods when the operational safety countermeasures are expected to be active based on certain triggering conditions (e.g., traffic, weather, nighttime). These results, together with crash modification factors, may be used in the benefit and cost analysis process to justify the application of specific countermeasures.