Дисертації з теми "SEAQT"
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1
Baniasadi, Fazel. "Structure Characterization and Electronic Properties Investigation of Two-Dimensional Materials." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/103904.
Анотація:
This dissertation will have three chapters. In chapter one, a comprehensive review on defects in two dimensional materials will be presented. The aim of this review is to elaborate on different types of defects in two dimensional (2D) materials like graphene and transition metal dichalcogenides (TMDs). First, different types of point and line defects, e.g. vacancies, anti-sites, guest elements, adatoms, vacancy clusters, grain boundaries, and edges, in these materials are categorized in terms of structure. Second, interactions among defects are discussed in terms of their rearrangement for low-energy configurations. Before studying the electronic and magnetic properties of defective 2D materials, some of the structures are considered in order to see how defect structure evolves to a stable defect configuration. Next, the influence of defects on electronic and magnetic properties of 2D materials is discussed. Finally, the dynamic behavior of defects and 2D structures under conditions such as electron beam irradiation, heat treatment, and ambient conditions, is discussed. Later as a case study, defects in a two dimensional transition metal dichalcogenide will be presented. Among two-dimensional (2D) transition metal dichalcogenides (TMDs), platinum diselenide (PtSe2) stands at a unique place in the sense that it undergoes a phase transition from type-II Dirac semimetal to indirect-gap semiconductor as thickness decreases. Defects in 2D TMDs are ubiquitous and play crucial roles in understanding and tuning electronic, optical, and magnetic properties. Here intrinsic point defects in ultrathin 1T-PtSe2 layers grown on mica were investigated through the chemical vapor transport (CVT) method, using scanning tunneling microscopy and spectroscopy (STM/STS) and first-principles calculations. Five types of distinct defects were observed from STM topography images and the local density of states of the defects were obtained. By combining the STM results with first-principles calculations, the types and characteristics of these defects were identified, which are Pt vacancies at the topmost and next monolayers, Se vacancies in the topmost monolayer, and Se antisites at Pt sites within the topmost monolayer. Our study shows that the Se antisite defects are the most abundant with the lowest formation energy in a Se-rich growth condition, in contrast to cases of 2D molybdenum disulfide (MoS2) family. Our findings would provide critical insight into tuning of carrier mobility, charge carrier relaxation, and electron-hole recombination rates by defect engineering or varying growth condition in few-layer 1T-PtSe2 and other related 2D materials. Also, in order to investigate the layer dependency of vibrational and electronic properties of two dimensional materials, 2M-WS2 material was selected. Raman spectroscopy and DFT calculation proved that all Raman active modes have a downshift when material is thinned to few layers (less than 5 layers). It was proven that there is a strong interaction between layers such that by decreasing the number of layers, the downshift in Raman active modes is mostly for the ones which belong to out-of-plane atomic movements and the most downshift is for the Ag2 Raman active mode. Also, I investigated the effect of number of layers on the band structure and electronic properties of this material. As the number of layers decreases, band gap does not change until the materials is thinned down to only a single monolayer. For a single monolayer of 2M-WS2, there is an indirect band gap of 0.05eV; however, with applying in-plane strain to this monolayer, the material takes a metallic behavior as the strain goes beyond ±1%.Doctor of Philosophy
Graphite (consisting of graphene as building blocks) and TMDS in bulk form are layered and with exfoliation one can reach to few layers which is called two-dimension. Two dimensional materials like graphene have been used in researches vastly due to their unique properties, e.g. high carrier mobility, and tunable electronic properties. Transition metal dichalcogenides (TMDs) with a general formula of MX2, where M represents transition metal elements (groups 4-10) and X represents chalcogen elements (S, Se or Te), are another family of two-dimensional materials which have been extensively studied in the past few years. Besides exfoliation, there are also synthesis methods to produce two dimensional materials, e.g. chemical vapor deposition and chemical vapor transport. Normally, after synthesizing these materials, researchers investigate structure and electronic properties of these materials. There might be some atoms which no longer exist in the structure; hence, those are replaced by either vacancies or other elements which all of them are called defects. In chapter 1, defects in graphene and transition metal dichacolgenides were investigated, carefully. Later, dynamic behavior of defects in these materials were investigated and finally, the effect of defects on the electronic properties of the two dimensional materials were investigated. Chapter two talks about a case study which is two dimensional 1T-PtSe2. In this chapter, 5 different kinds of defects were studied using scanning tunneling microscopy and spectroscopy investigations and density functional theory was used to prove our assumptions of the origin of defects. Also, another thing which is investigated by researcher is that how atoms in two dimensional materials vibrate and how the number of layers in the two dimensional material influences vibrations of atoms. Other than this, electronic properties of these materials is dependent upon the number of layers. When these materials are synthesized, there is a stress applied to the material due the mismatch between the material and its substrate, so it is worth investigating the effect of stress (strain) on the structure, and electronic properties of the material of interest. For this purpose, 2M-WS2 was exfoliated on Si/SiO2 substrate and the layer dependency of its vibrational modes was investigated using Raman spectroscopy and density functional theory calculation. Also, in order to investigate the influence of stress (strain) on the electronic properties of two dimensional 2M-WS2, a single monolayer of this materials underwent a series of strains in density functional theory calculations and the effect of strain on the electronic properties of this material was investigated.
2
Simsekoglu, Ozlem. "Correlates Of Seat Belt Use Among Turkish Front Seat Occupants." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606193/index.pdf.
Анотація:
CORRELATES OF SEAT BELT USE AMONG TURKISH FRONT SEAT OCCUPANTS
SimSekoglu, Özlem M.S., Department of Psychology Supervisor: Assoc. Prof. Dr. Timo Lajunen June, 2005, 79 pages This thesis included three separate studies, which were observational, interview and survey studies, on seat belt use among Turkish front seat occupants. The observation study investigated occupant characteristics and environmental factors affecting seat belt use. Seat belts were used significantly more among females and older occupants than among males and younger occupants
and on intercity roads, at weekends and in the afternoons than on city roads, at weekdays and in the evenings. The interview study investigated the common reasons for using and not using a seat belt in different trip types, qualitatively. Safety, situational conditions, habit and avoiding punishment were the commonly reported reasons for using a seat belt, while situational conditions, not believing the effectiveness of seat belt use, discomfort and no habit of using a seat belt were the commonly reported reasons for not using a seat belt, for most of the trip types. In the third study, seat belt use both on urban and rural roads were explained with the basic and extended Theory of Planned Behavior (TPB) models and Health Belief Model (HBM), using Structural Equation Modeling. Basic TPB model showed a good fit to the data, while extended TPB model and HBM showed a low fit to the data. Within TPB constructs, attitudes and the subjective norm had a positive and significant relation to intentions to use a seat belt. Results were discussed for their implications to traffic safety in Turkey, along with limitations of the study and suggestions for further studies.
3
Van, der Westhuizen Anriette. "The verification of seat effective amplitude transmissibility (SEAT) value as a reliable metric to evaluate dynamic seat comfort." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16453.
Анотація:
Thesis (MScIng)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: A rough road vibration stimulus was reconstructed on a shaker platform to assess the dynamic comfort of seven seats by six human subjects. The virtual seat method was combined with a paired comparison procedure to assess subjective dynamic seat comfort. The psychometric method of constants, 1-up-1-down Levitt procedure and a 2-up-1-down Levitt procedure were compared experimentally to find the most accurate and efficient paired comparison scheme. A two-track interleaved, 2-up-1-down Levitt procedure was used for the subjective dynamic seat comfort assessment. SEAT value is an objective metric and has been widely used to determine seat vibration isolation efficiency. There was an excellent correlation (R2 = 0.97) between the subjective ratings and estimated SEAT values on the seat top when the values are averaged over the six subjects. This study suggests that the SEAT values, estimated from averaged seat top transmissibility of six carefully selected subjects, could be used to select the best seat for a specific road vibration input.
AFRIKAANSE OPSOMMING: Ses persone het deelgeneem aan ‘n eksperiment, om die dinamiese ritgemak van sewe stoele te karakteriseer. ‘n Rowwe padvibrasie is vir die doel op ‘n skudplatform geherkonstrueer. Subjektiewe ritgemak is bepaal deur die virtuelestoel metode met ‘n gepaarde, vergelykingstoets te kombineer. Die psigometriese metode van konstantes, die 1-op-1-af Levitt procedure en die 2-op- 1-af Levitt procedure is vergelyk om die mees effektiewe en akkurate vergelykingstoets te vind. ‘n Tweebaan, vervlegde , 2-op-1-af Levitt prosedure het die beste resultate gelewer en is gekies vir die subjektiewe evaluasie van dinamiese ritgemak. SEAT-waarde is ‘n objektiewe maatstaf, wat gebruik word om te bepaal hoe effektief ‘n stoel die insittende van voertuigvibrasie isoleer. Daar was ‘n uitstekende korrelasie (R2 = 0.97) tussen subjektiewe dinamiese ritgemakevaluesies en SEAT-waardes in die vertikale rigting op die stoelkussing as die gemiddelde oor die ses persone bereken word. Uit die resultate van hierdie studie blyk dit dat SEAT-waardes, wat bereken is vanaf die gemiddelde sitplektransmissie van die ses persone, wat verteenwoordigend van die teikenbevolking is, gebruik kan word om die beste stoel vir ‘n spesifieke vibrasieinset te kies.
4
Klooster, Samuel John. "Vibration Suppression and Safety Seat Motion Design of a Hyper-Active Seat." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5241.
Анотація:
Whole-body vibration is an important problem facing operators of off-road vehicles. Research has shown that operators exposed to low-frequency whole-body vibration can experience temporary and even permanent injuries. One solution to this problem is to develop an active seat capable of canceling the vibrations felt by the operator. Several passive, semi-active, active, and fully active seats have been designed and built to address this problem. Furthermore, controllers have been developed to optimize the seat performance. Vibration cancellation seating systems seem to be a promising and practical way to reduce the effects of whole-body vibration.
To extend developments in this area, a Hyper-Active seat has been designed and built at the Georgia Institute of Technology. The seat utilizes a 3 Revolute-Prismatic-Revolute (RPR) parallel manipulator design which allows for the independent control of the vertical, horizontal and pitch angle directions. The seat is powered using three hydraulic actuators which are controlled using MATLAB's Simulink, xPC Target, and Real-Time Workshop. Controllers were developed to control the position of the seat, as well as cancel unwanted vibration. To test the performance of the Hyper-Active seat, the system identification of the seat was undertaken using open-loop forcing functions. The seat was evaluated in each degree of freedom to understand the potential of the seat to cancel harmful vibration.
In addition to reducing harmful vibrations, the seat can double as a safety seat to reduce injuries during a frontal collision. If the front edge of the seat bottom can be raised very quickly, then the forward motion of the passenger can be reduced during a crash. An optimal method for performing this motion is developed.
5
Niklasson, Johan. "Conceptual Design of Seat Belt Installation for Rear-facing Child Car Seat." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73129.
Анотація:
Children are more vulnerable in vehicles compared to adults in collisions. Two main reasons are the different body structure between these two and vehicles are more designed to fit adults. Children’s head is larger relative to their body mass and their neck muscle ligaments are still not fully developed. Children are therefore in need of a restraint system that match their anatomy to make them protected during transportation in vehicles. Crash tests have shown that if children up to the age of five use rear-facing child car seats are the chances reduced of injuries by five times compared to front-facing. This report describes the development project of a concept which enables to fasten a rear-facing child car seat with the car seat belt. The objective was to design the fastening components for a rear-facing child car seat that suits children up to five years and considering the regulations, ECE R44, and the Swedish Plus test. This is a Master thesis that has been in collaboration with Company Xand Havd Group in Gothenburg. The project aimed to deliver a digital concept of the fastening components with information about the material, manufacturing methods, product costs, and design form. Also, was the aim to gather information through the project on what it takes to develop a rear-facing child car seat. The project consisted of five phases: planning, pre-study, ideation, detailed design and at last presentation of the result. The first phase was to plan and coordinate the project. A pre-study was then made investigating the products on the market, interviews with both users and experts regarding safety for children in vehicles, relevant literature for developing a child car seat was also collected and regulations were studied. The ideation phase developed ideas and three concepts were taken forward for development. One concept was chosen after decision making and the concept was more detailed designed in CAD.The result is presented through a CAD model which illustrates the design form and chosen material. The result is a concept that fastens the car seat belt with two hooks which can be connected to the child car seat base. In the base is two buckles designed to connect with the hooks, which uses the same fastening way used in the vehicles to fasten passengers. This is supposed to increase the usability of the installation. Material, manufacturing methods and product costs have been considered and are presented with the result.
6
Seigler, Thomas Michael. "A Comparative Analysis of Air-inflated and Foam Seat Cushions for Truck Seats." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/9702.
Анотація:
A comprehensive comparison between an air-inflated seat cushion designed for truck seats and a commonly used foam cushion is provided, using a single-axis test rig designed for dynamic seat testing. Different types of tests are conducted in order to evaluate various aspects of each type of cushion; in terms of their response to narrow-band (single frequency) dynamics, broadband input of the type that is commonly used in the trucking industry for testing seats (ISO2), and a step input for assessing the damping characteristics of each cushion. The tests were conducted over a twelve-hour period -- in four-hour intervals -- measuring the changes that occur at the seat cushion over time and assessing how these changes can affect the metrics that are used for evaluating the cushions. The tests indicated a greater stiffening of the foam cushion over time, as compared with the air-inflated cushion that showed almost no change in stiffness when exposed to a static weight for twelve hours. Furthermore, pressure measurements at the seat showed higher-pressure concentrations for the foam cushion at the bony prominence of the seat profile -- namely, the ischial tuberosities -- as compared to the air-inflated cushion. A series of tests aimed at evaluating the damping properties of each cushion showed both cushions to have nearly identical damping properties. Other methods used for evaluating the dynamic properties of the two seat cushions included those recommended by studies in the past, as well as new techniques that were developed specifically for this study. The new techniques, named Seat Pressure Distribution (SPD%) and Area Pcrms (aPcrms) for the purpose of this study, are formulated such that they can best highlight the dynamic differences between different types of seat cushions, and their effect on driver comfort. The results show that the air-inflated seat cushion can provide significant improvements in pressure distribution between the seat cushion and the driver, therefore providing a more comfortable ride and causing less fatigue.Master of Science
7
Jannesson, Johan. "Seat heating smart algorithm." Thesis, University West, Department of Technology, Mathematics and Computer Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-338.
Анотація:
The goal of this project was to build a model and a controller for the seat heater and steering wheel heater on the SAAB cars. SAAB manufactures two different car models 9-3 and 9-5. The goal is to control the seat heater in both car models without any temperature sensor in the seat, this due to cost reduction. Several tests have been carried out booth in climate chambers and during road tests. These tests have in the end lead to a mathematical model for the temperature dependence and this model has been used to design an open loop controller for the seat heater.
8
Schoenmakers, Sean A. "Handicapped car lifting seat." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/62991.
Анотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Cataloged from PDF version of thesis.
Includes bibliographical references.
Currently there is a lack of assistance in automobile usage for the older people of our society. In an attempt to combat this problem, this thesis designs and builds a working conceptual model of a handicapped car lifting seat. An initial cost analysis is performed, an apparatus is designed, all necessary materials are gathered, an apparatus is constructed, and the device is tested. The result was the successful completion of a device that successfully assists in the lifting of up to a 300 lb. person out of their car. With some further development, this handicapped car lifting seat could hopefully be used in real life.
by Sean A. Schoenmakers.
S.B.
9
Eriksson, Andreas, Johanna Lund, and Fredrik Lundh. "TaS - Take a Seat." Thesis, Malmö högskola, Institutionen för konst, kultur och kommunikation (K3), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-21741.
Анотація:
Humans have always been fascinated by the thought of bringing non living objects to life. Wewanted to explore the possibilities of trying to create an artefact that the audience wouldconsider possess emotional states and have a life of its own.TaS is a interactive chair that functions as a social entity. The idea is to try and enhance thebond between human and artefact, based upon the emotional connection. We try and produce,enhance and maintain this bond through curiosity based interaction.Bachelor thesis in Interaction Design by Andreas Eriksson, Johanna Lund and Fredrik Lundh,spring term 2008, Malmö University, K3 School of Arts & Communication.
10
Huertas, Dominguez Ana, and Bueno Maria del Pilar Perez. "ENTRY/EXIT IMPROVED SEAT FOR A PASSENGER’S CAR : Sliding Seat for Volvo S80." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-6516.
Анотація:
This thesis work is focused on the design of a mechanism for the passenger’s seat of a Volvo S80. This mechanism will facilitate the problems arised when somebody with limited mobility, either permanent or temporal, is entering or exiting the vehicle. The main aim is to obtain an affordable device that enhances the life of those with reduced mobility, but paying special attention to those who do not receive any kind of economical help from the government. The idea is to be able to move the seat to the outside of the car so that one can seat with no special effort. Then, the mechanism, manually, performs the movements to bring it back to the inside. The concept of being manual is to avoid electronic devices that will surely increase the cost. In this project, a possible design solution has been developed. A model was created with Autodesk Inventor 2012. The three basic positions of the mechanism were studied to determine the structural behavior of the product. For these studies, a load compensating the weight of a human was applied and the stresses and the deformation were analyzed by Finite Element Methods and the study was concluded when the safety factor was over 2.
11
Wei, Lin. "Predicting seat transmissibility from seat impedance and the apparent mass of the human body." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312865.
12
Li, Yiran. "Height adjustable wheelchair seat design." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44767.
Анотація:
Full time wheelchair users are at a height disadvantage during many function activities, such as transferring or reaching. Retrieving objects from the ground or a higher shelf while seated in the wheelchair can be both difficult and unsafe. Lateral transfers between surfaces at different heights can be difficult and unsafe. Sit-to-stand transfers are made simpler with a higher seat. This research project seeks to assist reach and transfers by designing a system to raise and lower a wheelchair seat over a 4'' range.
The project included several needs assessment: 1) by conducting interviews and surveys, identify design needs from different stakeholder groups; 2) analysis of stakeholder groups' feedback and synthesis into design criteria; and 3) creation of design concepts for the adjustable height wheelchair seat; 4) evaluation of the design by setting up heuristic evaluation criteria and perform user testing; 5) design revision design based on user's performance and feedback. The design process included fabricating and testing of various concepts, validating design through user testing, and addresses technology transfer of the device.
13
Dedic, Haris. "Humidity sensor for car seat." Thesis, University West, Department of Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-785.
14
Doroftei, Teodor, and Omar Osorio. "Operator seat undercarriage re-design." Thesis, KTH, Maskinkonstruktion (Inst.), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141666.
Анотація:
Väldigt få av dagens skogsmaskiner har dämpning vid hjulen. Detta resulterar i att den enda dämpning operatören har tillgång till för att dämpa vibrationer och stötar från marken, är den som sitter under sätet, det dämpande underredet. Tyvärr håller dagens undereden icke måttet, då de är främst designade att användas i en helt annan miljö, oftast i lastbilar och bussar. Förutom problemet med kort livslängd, så finns problemet med att man ej kan få optimal dämpning vid lägsta och högsta positionen, på grund av hur konstruktionen är utformad. I detta examensarbete så görs ett försök att hitta en annan typ av dämpnings- och höjdläges-funktion som gör att höjd och dämpning ej är beroende av varandra, vilket skall resultera i optimal dämning oavsett höjd. Förutom detta så skall designen också hålla längre samt dämpa vibrationer och rörelser åt fler håll än bara vertikalt.Den resulterande konstruktionen analyserades sedan digitalt, för att ta fram de optimala dämpnings- och fjäder- konstanterna, samt egenfrekvenserna. Slutligen ges rekommendationer för design, analyser och övrigt fortsatt arbete som behövs för att kunna tillverka en prototyp.Very few of today’s forest machines have damping at the wheels. The only damping that the operator has to shield him from the vibrations and shakes is the seats undercarriage. Unfortunately, today’s undercarriage do not measure up to the task, as they are often designed for trucks and busses, not to be used in a harsh environment as a forest. Except the short lifespan problem, there is also the issue of optimal damping. Today’s design does not allow for optimal damping at the maximum and minimum height positions.This Master´s Thesis project aim at creating a new and improved design that would separate height adjustment and damping, with the purpose to provide optimal damping within the entire height adjustment range. All this and at the same time making the design sturdier, with a greater lifespan, and to be able to damp vibrations and motions in more than one direction. The resulting design was then digitally analyzed to find out the optimal damping and spring coefficients, as well as the natural frequencies. Finally recommendations are given for design, analyses and further work that are needed to manufacture a prototype.
15
Brown, Sylvester H. "Army Reserve training seat allocation." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FBrown.pdf.
16
McConeghy, David Walker. "Shifting the Seat of Awakening." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1154557985.
17
Bradley, Andrea Danielle Goggin Kathy J. "Seat belt use among African Americans." Diss., UMK access, 2005.
Анотація:
Thesis (M.A.)--Dept. of Psychology. University of Missouri--Kansas City, 2005."A thesis in psychology." Typescript. Advisor: Kathy Goggin. Vita. Title from "catalog record" of the print edition Description based on contents viewed March 12, 2007. Includes bibliographical references (leaves 42-46). Online version of the print edition.
18
Patlu, Srikanth. "Occupant restraint modeling seat belt design." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1174316672.
19
Alfadhli, Abdulaziz. "Active seat suspensions for automotive applications." Thesis, University of Bath, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760992.
Анотація:
Vehicle drivers are exposed daily to harmful low-frequency vertical vibration over the frequency range of 1-20 Hz. This reduces ride comfort and safety as well as possibly causing long-term harmful effects on human health in the form of lower back pain and driver fatigue. Accordingly, intensive work has been undertaken in this field on active seat suspension systems that have superior performance over a wide frequency range compared with passive and semi-active systems. One of the main features of these systems is the control strategy that is used to generate the demand control force and whilst many control strategies have been investigated in this area; their practical implementation is challenging as they require unavailable or expensive system states. Hence, in this thesis, a novel and cost-effective strategy has been developed that uses measurable and inexpensive displacement and velocity preview information from the vehicle suspension. In addition to these practical advantages, employing a prior knowledge of the disturbance in the control strategy increases the ability of the active seat to react rapidly to disturbances and hence provides a supplementary improvement to the vibration attenuation performance. The potential application of this strategy for an active seat suspension is investigated through both simulation and experimental tests. Firstly, for simplicity, the control force is defined from this suspension preview information based upon a linear control approach, with optimum gains using an integrated simulation model of a linear quarter vehicle model (QvM) and one degree of freedom of seat suspension. These gains are obtained off-line by optimising ride comfort in terms of the vertical Seat Effective Amplitude Transmissibility (SEAT) factor using a genetic algorithm (GA) and considering the physical constraints on both the limited seat suspension travel and actuator force capacity. The experimental tests are performed using a prototype active seat suspension installed on a multi-axis simulation table (MAST), which has been developed to mimic the dynamic motion of the sprung mass of the (QvM) through the principle of hardware-in-loop (HIL) simulation. Moreover, the experimental test rig is used to estimate the characteristics of a passive seat suspension as well as the driver’s body model. The ‘preview’ control strategy is examined according to the ISO 2631-1 standard, in both the frequency and time domains, under a range of operating conditions, including different road profiles and vehicle speeds. Both simulation and experimental results reveal that, in comparison with a passive seat suspension, employing this strategy for the active seat system significantly improves ride comfort, especially over the HBSF range (4-8 Hz). Also, experimental tests demonstrate that combining both the preview information with the vehicle body and seat acceleration feedback states provides further improvement in the vibration attenuation level, achieving up to a 19.5 dB reduction over the HBSF range. The linear control approach cannot always satisfy the physical constraints over a range of operating conditions and thus, to overcome this fault, a fuzzy logic controller (FLC) is selected. Accordingly, two novel and cost-effective FLCs are designed and optimised using the Particle Swarming Optimisation (PSO) algorithm. The feedforward fuzzy logic controller (FF-FLC) uses similar preview information as in the linear control approach, while the feedforward/feedback controller (FFFB-FLC) utilises a combination of both the preview information with seat suspension deflection and velocity feedback states. Once again, the simulation and experimental results confirm the effectiveness of these strategies for attenuating the vertical vibration, especially over the HBSF range, in which the FFFB-FLC provides the best performance as well as the highest robustness level at a variety of different driver weights and vehicle speeds. The application of the preview enhanced controller for an active seat suspension in a full vehicle model has been investigated in the simulation. Accordingly, three FLCs strategies, namely, front-left suspension (FLS-FLC), front-axle (FA-FLC) and four wheels (4W-FLC), have been developed based upon which vehicle suspension or/ suspensions are used to acquire the preview information. The former involves utilising suspension displacement and velocity preview information from the vehicle suspension nearest to the driver’s seat. The FA-FLC uses similar preview information, but from the front-left and front-right suspensions, whilst the 4W-FLC controller employs similar preview information from all the vehicle suspensions. Numerical results show that the proposed controllers are very useful in attenuating the vertical acceleration at the driver’s seat compared with a passive alternative. The 4W-FLC provides the best vibration attenuation performance, independent of the vehicle speed. Finally, to reduce the implementation cost of this controller, a practical alternative has been developed that requires less measured preview information. In conclusion, using the preview information enhanced controller for an active seat suspension provides a practical and cost-effective system that improves ride comfort and reduces driver fatigue.
20
Despotovski, Natali, and Sonja Vuletic. "A Product Development of Safety Car Seats for Children." Thesis, Högskolan i Halmstad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-37041.
Анотація:
Car accidents happens daily, and it is very important to protect all involved in a carno matter the age. Persons that are old enough and can take care of themselves, usescar seat belts to be protected in traffic. A child, however, must be placed andfastened in a safety seat by a parent or another caregiver, to be fully protected. Children that are correctly secured in safety seats have a 2.7 times bigger chance tosurvive a car crash without serious injuries compared to unstrained children (Berget al., 2000; WHO,2004). Regardless tests and safety seats that are available ontoday’s market, there are still issues that needs to be eliminated. Daily users of thisproduct are a good starting point since these people want a safe seat for their childthat can be easy to install and affordable; and they can best tell what issues theyencounter. Based on several scientific articles in a combination with interviews andobservations, issues with the safety seats could be confirmed. The primary issue isthe seat belt that is attached to the safety seat. Children can develop a habit ofwriggling out of the belt in safety seats. There are belt collectors available on themarket which holds the shoulder belts in place. In this way, it is harder for thechildren to slide out of the belt and helps to keep the belt properly positioned(BeSafe, 2018). Instead of having this as an accessory, it has been considered in thebelt that have been developed. Another issue is that the belt is complicated tofastened since two straps has to be simultaneously clicked in the belt buckle. If thisis done incorrectly, the belt cannot be fastened, and it takes time to try it again. Tomake this easier, two straps and the strap between the child's leg will be fastenedseparately in a seat buckle each. In this way, parents and other caregivers will beable to fasten the belt easy and properly. They will also be sure that the child issafely fastened and will minimize injury during an accident or another situation.
21
Koh, Chong Hin 1975. "Advanced aircraft seat design : solving the problem of rearward space intrusion with a sliding-out seat back." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9484.
Анотація:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1999.Includes bibliographical references (p. 73-77).
An aircraft economy-class seat that reclines via a sliding-out backrest was designed, fabricated and tested for comparison with a baseline aircraft seat. The goal was to design a seat that was at least as comfortable as the baseline seat so as to demonstrate the viability of replacing the usual backwards recline feature with a sliding-out mechanism. This would solve the problems of space intrusion associated with seat recline. Three additional features were included on the seat: an adjustable lumbar support, a height-adjustable winged headrest and a height-adjustable tray. The seat was evaluated via human subject responses and pressure distribution maps. Results obtained from the experiment showed that the seat was as comfortable as a baseline seat, if not better, and there was no statistical indication that subjects found the seat more uncomfortable. Pressure distribution maps corresponded well to the subject responses. Based on the test results, the concept is deemed viable and its implementation is recommended on daytime flights that are over three hours long.
by Chong Hin Koh.
M.Eng.
22
Alharbi, Fawaz Ali. "Evaluation of Relationship of Seat Belt Use Between Front Seat Passengers and Their Drivers in Dayton, Ohio." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1404829225.
23
Erol, Tugra. "The Visual Perception Of Automobile Seat Comfort." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607768/index.pdf.
Анотація:
The visual domain design constitutes the general designers communication basis for communicating messages of product attributes. In the design of an automobile seat where mainly the accommodating functions remain constant, an automobile seat&rsquos &ldquo
style&rdquo
affords the ability to provide certain meanings with affective connotations. Treating style aesthetics as a source of information, the communication of &ldquo
comfort&rdquo
can be provided via forms and other attributes. The literature provides strong evidence that comfort is related with aesthetics of any object in use, especially creating expectations towards the product. The &ldquo
Aesthetics of comfort&rdquo
can be explained as a variable intensity &ldquo
feeling&rdquo
or &ldquo
attitude&rdquo
regarding an entity of factors or characteristics of a multidimensional construct. Implemented by different layouts and cues, the consumer should be assisted in understanding the qualities of an automobile seat, such as comfort. As a result of the field study conducted, significant difference was found to exist in between the perception of visual comfort three production seat designs. A positive attitude about comfort towards an automobile seat was found to be influential in positively effecting the perception of seated comfort.
24
Erol, Tugra. "Vibration Exposure Of Front Seat Car Passengers." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605740/index.pdf.
Анотація:
Vibration in the vehicle environment has long been investigated considering the driver's exposure. However not only drivers but also the front seat car passengers are exposed to considerable amount of vibration. In order to investigate the phenomenon, this research consisted of three stages. In the first stage of the study, model analysis has been carried out. Based on the results it has been suggested that increased damping in the lumbar area in contact with the backrest can decrease the vibration transmission. The second stage comprised of the laboratory studies. Based on the results attained from the model, waist belts filled with different fluids having different coefficients of viscosity were prepared and tested. The inclination of the backrest angle was chosen as the second parameter. The cushions having ready-made gel mediums were seen to be effective in reducing low frequency vibrations where the angle of inclination affected the response of the cushions. In the third part of the thesis, field measurements were carried out in order to confirm the results attained in the laboratory. It was observed that the inclination of backrest angle played a major role in the exposure of the passenger in fore and aft direction. The cushions proved to be effective at certain frequencies in the field, differing due to the design and the medium.
25
Öhman, Tanja. "Flexible touch screen for Rear Seat Entertainment." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-5328.
Анотація:
Rapporten beskriver förslag på framtidens ”Rear Seat Entertainment” som baseras på användning av pekskärm, istället för de DVD-baserade TV-skärmar som finns i t ex Volvo S80 i dagsläget. Projektet utfördes som ett examensarbete inom integrerad produktutveckling vid Högskolan i Skövde. Syftet med arbetet var att hitta lösningar som möjliggör användning av ”touchteknik” som kräver armavstånd till displayen. Arbetet delades upp i tre delar där val av pekskärmsenhet (inbyggd eller mobil), positionering av pekskärmen i bilen enligt ergonomiska rekommendationer, samt anpassning för olika stora personer inkluderade barn och utformning av infästningselement har utvecklats. Arbete inleddes med litteraturstudier om interaktion av pekbaserade interface, målgruppsundersökningar, sammanställning av marknadsundersökningar, trendanalyser samt ergonomiska förutsättningar och miljöutvärderingar. För idégenereringen användes kreativa och systematiserade metoder. Urval av idéer skedde i samråd med Volvo och med hjälp av en konceptvalsmatris. Det slutliga konceptet baseras på användningen av mobila pekskärmsenheter. Dessa motsvarar bäst de i dagsläget ställda kriterierna på användning, ekonomi, miljö och flexibilitet. Dessutom erhålls en enklare mjuk- och hårdvaruuppdatering. Positionering av pekskärmar i bilens baksäte gjordes med hjälp av ergonomiska rekommendationer samt databaserade beräkningar och simuleringar. Utformning av infästningselementen anpassades till kravspecifikationen och resulterade i ett fäste som håller fast enheten med hjälp av permanentmagneter som byggs in i ett infästningselement på stolens baksida och ett i fodralet för surfplattan. Arbetet har lett till skärmar som enkelt kan fästas med magnetkrafter.
26
CALVIN, LINARES PABLO. "CONCEPT FOR A PORTABLE ASSISTIVE LIFTING SEAT." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industridesign, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-43678.
Анотація:
This project consists of the design of a concept for a portable assistive seat in collaboration with IKEA. The aim of the project is to create a solution that fits within the Omtänksam family of products and shares the company’s values of what is so-called Democratic Design: Form - Quality - Low Price - Function – Sustainability The Omtänksam Family is focused on products that can help the elderly to have a more comfortable life while blending with the home environment. A portable assistive Lifting Seat is a real need for many people that require some extra help when standing up or sitting down. The main goal of this project is to design a cheap, safe, simple and light product that can assist people for reducing the effort that is required from them. The product must be comfortable, easy to transport and friendly to interact with. Considering a mass manufacturing perspective is very important to meet the previously formulated requirements. The force that the assistive seat releases must keep performing efficiently during the product service life. A locking system must be provided for avoiding the lifting force to act when the user is sitting, assisting only when it is demanded. This Thesis describes the process of designing a concept for a Portable AssistiveLifting Seat involving different areas such as ergonomics, semantics, manufacturing, mechanical engineering and materials science. The design approach in this case is driven by the Democratic Design Principles combining the human-centered design with a market perspective. The result takes advantage of form and material for avoiding the need for any extra lifting mechanism. This solution is way simpler than any other one existing in the market and it integrates the solution for many different problems in one single piece. This simplification of the problem allows reducing the production cost and helps to meet the intended requirements creating an innovative product for the market.
27
Davis, James Raymond. "Back seat driver : voice assisted automobile navigation." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14225.
28
Fonte, William Giacomo. "An automotive lower back seat system design." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/32140.
29
Stuart, Dahlgren Tolla. "Experiment as method : [one seat per week]." Thesis, KTH, Arkitektur, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229700.
Анотація:
A sitting device – an object that holds a human body above ground. The project is an experiment of method and material in the human scale. A series of tests of building methods and materials have been carried out in the project. Preconceived ideas of seating as well as how different materials perform, have been examined. Design development and process have been based on full scale sketching and intuitivity. Questions at issue:What is a chair? How do different materials perform? What does a design process based on full scale sketching and intuivity look like? When does design happen?
30
Ereq, Khaled. "Active Suspension Seat for High Speed Craft." Thesis, KTH, Marina system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234825.
Анотація:
Master of Science thesis in Naval Architecture presents a study and the performance of an active seat suspension with the purpose to suppress shocks, caused by slamming in High Speed Crafts (HSCs). The system is modelled and simulated with the aid of the Mathworks software Simulink, with the main objective to evaluate if the active suspension seat has the potential to mitigate slamming impact loads to a larger extent compared to a passive suspension seat. The active suspension model is developed by adding a PD-controlled actuator in parallel with the spring and damper of a passive seat’s suspension. This paper presents the performance study of an active suspension seat where the seat is given a single impact load as input. The results are then compared to a comparable passive seat. The most promising results show that the active system can reduce the passenger seat’s acceleration response by roughly 30 %. This is achieved on the expense of an increased stroke length, from 30 mm for a comparable passive system, to 34 mm for the active system. To achieve this the actuator need to provide up to 900 N of force with a rise-time of 15 ms. During the assessment of the suspension seat performance four key performance indicators(KPI) were found to be of significance. Those are the seat response acceleration, seat displacement relative to the seat base, settling time and the zero crossing time. The seat acceleration is directly proportional to the load that the passenger is being subjected to. Hence, the acceleration is the property that needs to be reduced in order to decrease risk of injuries. The stroke length of the seat in relation to the seat base should be kept to a minimum for several reasons. One being the risk of bottoming out the suspension if the stroke length is too high, risking damage on equipment as well as injuries on passenger. Since the conditions on sea entail series of impact loads on the hull, the settling time need to be as short as possible to avoid accumulating the displacement. This is caused when the seat has not yet returned to its neutral position before next impact occurs. To define the response time of the system, the zero-crossing performance indicator was defined. Zero-crossing time is defined as the time from when the displacement of the seat starts (the suspension being compressed) until it returns and crosses the neutral position, regardless if the suspension stops at the neutral position or continue extending. A correlation was found between the zero-crossing time and the settling time. Both KPIs are dependent on the 𝑃𝐺𝑎𝑖𝑛 (the proportional part of the PD-control)and what is found is that a short zero-crossing time entail an increased overshoot, that in turn results in a longer settling time due to the seat’s oscillation about the neutral position. The active suspension seat model in this paper can be further developed and evaluated with respect to the performance indicators stated by (European Union, 2002) like VDV, RMS acceleration values etc.Den här rapporten, som är en del av ett examensarbete inom marina system på masternivå, beskriver studien av prestandan för en stol med aktiv stötdämpningsmekanism, avsedd att användas i höghastighetsfartyg med syftet att reducera de vibrationer och stötar som passagerare utsätts för. Krafterna som stolen utsätts för är en följd av de kraftiga stötar somuppstår när båten färdas i höga hastigheter och studsar på vattenytan. Det huvudsakliga syftet med studien är att utreda om en stol med aktiv dämpning kan reducera vibrationer och stötar i högre utsträckning jämfört med en motsvarande stol med passiv dämpning. Den aktiva stolens rörelse kontrolleras med hjälp av ett ställdon som i sin tur styrs av en så kallad PD-kontroller. För modellering samt simulering av stolens beteende används Mathworks mjukvaruprogram Simulink. Rapporten beskriver hur den aktiva dämpningen presterar och beter sig när systemet utsättsför en kraftig stöt. Detta jämförs sedan med den passiva dämpningens prestanda. Resultatenvisar att accelerationen för det aktiva systemet är cirka 30 % lägre jämfört med det passivasystemet. Denna prestation är på bekostnad av en längre slaglängd för stolen, som för det aktiva systemet är ca 34 mm jämfört med 30 mm för det passiva systemet. För detta krävs att ställdonet kan leverera en kraft på cirka 900 N och har en responstid på cirka 15 ms. Studien visar att fyra parametrar är av intresse för att bedöma systemets prestation när det utsätts för en stöt. Dessa är stolens acceleration, stolsitsens maximala slaglängd i förhållandetill stolens bas, tiden det tar för stolen att återgå till dess jämviktsläge samt tiden det tar förstolen att återgå eller passera jämviktsläget efter att det har utsatts för en stöt. Stolensacceleration är direkt proportionerlig mot kraften som passageraren utsätts för. Därför är det accelerationen som behöver reduceras för att minska risken för skador. Slaglängden behövervara så liten som möjligt för att undvika att dämpningsmekanismen bottnar, vilket skulle medföra risk för skada på både utrustningen och passagerare. Förhållandena där höghastighetsfartyg opererar medför ofta att skrovet utsätts för serier av stötar, vilket medför att stolens förflyttning (slaglängd) från neutralläget riskerar att ackumuleras över tid om tiden det tar för stolen att returnera till neutralläget är för lång. Tiden det tar för stolen att återgå eller passera jämviktsläget, efter att ha börjat flytta sig från jämviktsläget, definierades som en nyckelparameter för att bestämma hur snabbt systemet reagerar. Det visar sig finnas enkorrelation mellan responstiden och tiden som det tar för stolen att helt återgå tilljämviktsläget. Båda egenskaperna är beroende av den proportionella parametern 𝑃𝐺𝑎𝑖𝑛, som är den proportionella delen av PD-kontrollern. Denna parametern kan ökas för att minskaresponstiden och det har till följd att stolens överslag ökar, vilket medför att stolen oscillerar kring jämviktsläget efter en stöt. Modellen av det aktiva systemet i den här rapporten kan användas för vidare utvärdering, med avseende på de prestandaindikatorer som beslutats av (European Union, 2002), såsom VDV-värden och RMS-accelerationer etc.
31
Teo, Cheng Hang 1976. "Advanced aircraft seat design : the webbing concept." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/50543.
Анотація:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1999.Includes bibliographical references (leaf 95).
Air travel is so common in this day and age that any significant improvement in seat comfort on board a commercial passenger jet is likely to affect almost everybody. A proposed design concept in this project is the use of webbing as the substitute for current foam cushioning in the seat back. The result is a webbing-foam hybrid cushioning design that utilizes the benefits of both cushioning types to maximum effect. Experimental tests suggest that this design would also provide better overall comfort for the passenger. As a result, both consumer and industry would profit immensely from the implementation of such a design.
by Cheng Hang Teo.
M.Eng.
32
Ofori-Boateng, Akua Boabema. "A Study of the Effect of Varying Air-Inflated Seat Cushion Parameters on Seating Comfort." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/33926.
Анотація:
For many years seat cushions have been investigated for their ability to reduce seating discomfort. The objective of this thesis is to examine air-inflated seat cushions to determine how seating comfort (determined by pressure change rate) is affected by changing various parameters of the cushion. To this end, a mathematical model was built using MatLab and SimuLINK to accurately represent the cushion and its response. Different aspects of the cushion, such as seating area, outlet size, cell height, and material elasticity are varied to determine how they each affect seating comfort. For each parameter three different weights are tested to see how the trends observed per parameter are affected by a person's weight.
The results of this study indicate that by changing the base radius, the cell height, the outlet diameter, and the material elasticity of each cell, it is possible to improve seating comfort, as determined by pressure change rate. The study confirms that comfort levels increase with increasing seated area. The study also shows that although increasing the weight of a person decreases the comfort performance of the cushion, not all the trends observed when the cushion parameters are varied remain the same as the person's weight is changed. The trends observed when the cell height and outlet diameter are varied are not affected by the subject weight but all the other trends changed as the subject weight was changed.
Master of Science
33
Posner, George. "Do Seat Belt Laws Drive Up Insurance Premiums?" Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/cmc_theses/423.
Анотація:
If you have to wear a seat belt when you drive, are you safer? Intuitively, it may seem that the answer is yes. After all, if you are wearing a seat belt and get in an accident, you are half as likely to die, and 62% of fatal accident victims were not wearing seat belts at the time of accident. The Centers for Disease Control and Prevention, the National Highway and Transportation Safety Administration, the Governors' Highway Safety Administration, and many other organizations highly recommend wearing seat belts. The NHTSA claims that in 2010 alone, approximately 12,500 deaths were prevented by seat belt use alone. Seat belt laws clearly reduce the chance of death to vehicle occupants in a given auto accident.
In response to these findings, the federal government has made the release of highway funds to states contingent on the passage of state laws mandating seat belt adoption. Laws mandating seat belt use, along with extensive campaigns to raise public awareness, have caused seat belt use to rise from 69% in 1998 to 88% in 2009. As of this writing, laws mandating the use of seat belts when driving have been passed in every state save New Hampshire. Intuitively, this should make roads safer because seat belts make an accident more survivable.
Does wearing a seat belt, however, make that accident more likely to occur in the first place? If a driver wears a seat belt now and I didn't before, does he feel safe enough to take more risk? In this paper, I examine this question using insurance premiums as a proxy for the likelihood of an accident. The rest of the paper is organized as follows. Section 2 offers background information, including a framework with which to interpret a driver’s actions and a review of the relevant literature. Section 3 contains details on the data analyzed. Section 4 covers the results of my preliminary data analysis, model specifications, and robustness checks. Section 5 concludes.
34
Al, Hayani Musab. "Offline Programming of Robots in Car Seat Production." Thesis, Högskolan Väst, Avd för automation och datateknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-5415.
Анотація:
Company Purtech in Dals-Ed manufactures molded polyurethane (PUR). Examples of products that include polyurethane are car seats. Robots are used to fill the molds with PUR and to apply the release agent (wax) in the empty molds. Turning from online programming into a graphical offline programming of release agent spraying robots is going to simplify the process by: Applying less of release agent to avoid polluting environment, to produce an easier removal of moulds, for the sake of homogeneous moulds and for economical saving in the cost of release agent Adaption of spraying paths to variation in production speed. Programming of complex spraying trajectories to deal with sharp geometrical subsurface Decreasing onsite programming time (when program a new workpiece or modify an old one); so that robots would be free for production. While turning into offline programming brought the challenges of: Impact of variation in the production speed Lack of 3D models of workcell’s equipments Robot joint configuration when paths and robtargets are in move. Physical Joint limits, Singularities & Reach limits Collisions within the cell space. At the end, the following objectives are successfully met: Adaption of spraying programs to variation in production speed by developing and embedding a method in those programs. Graphical offline generation of spraying trajectories and optimization of those trajectories to the Purtech condition of spraying allowed time for each carrier. Simulation of release agent spraying process; and producing of a well structured RAPID program that reflect the simulated process.
35
Kolich, Mike. "Ergonomic modeling and evaluation of automobile seat comfort." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0030/NQ62325.pdf.
36
Kimmel, Tom. "A study of the judgment seat of Christ." Theological Research Exchange Network (TREN), 1988. http://www.tren.com.
37
Johnson, Kerry Michael. "The nature of the judgment seat of Christ." Theological Research Exchange Network (TREN), 1990. http://www.tren.com.
38
Gambel, Ray, David Lundy, William Murphy, and Southmost Consulting. "Analysis of Transportation Alternatives for Ejection Seat Training." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/7068.
Анотація:
EMBA Project ReportEXECUTIVE SUMMARY Student Military Aviators who complete primary flight training at Training Wing FOUR and select jets for their advanced training track will require Naval Aviation Survival Training Program (NASTP) Class 1 training until the T-6B replaces the T-34C as the primary flight training aircraft. This Class 1 training instructs students in ejection seat equipment and procedures for emergency egress of their new aircraft. Of the eight available Aviation Survival Training Centers (ASTC) Training Wing FOUR sends its students exclusively to NAS Pensacola. Training Wing FOUR utilizes a TC-12B training aircraft for the logistical transport of students to and from Class 1 training approximately twice weekly, called the DJET. CDR Christian Schomaker, Training Wing FOUR Operations Officer, commissioned this study to provide an analysis of alternatives to the current method of transporting students. RECOMMENDED OPTIONS A. Provide all flight students Class 1 training at ASTC Pensacola, Florida while in Pensacola as part of the Aviation Preflight Indoctrination (API) curriculum prior to permanent change of station to Corpus Christ, Texas. B. Adjust the DJET flight schedule to a Sunday departure rather than a Friday departure, resulting in a $209.00 savings per student of per diem cost which amounts to approximately $21,000.00 per fiscal year. C. Readdress current local restrictions and classification of student naval aviators as aircrew to enable multi-engine student flight training on DJET flights. D. Consider utilizing other ASTC facilities; specifically, aligning the Class 1 ejection seat training with the required Centrifuge-based Flight Environment Training (CFET) at ASTC Lemoore.
39
Sun, Xuan. "Analysis and vibration improvements of a forwarder seat." Thesis, KTH, Maskinkonstruktion (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143638.
Анотація:
I skogsbruket är både förare och fordon utsatta för höga vibrationsnivåer. Stolen i dagens skotare är en av de viktigaste delarna för att kunna isolera föraren från helkroppsvibrationer (WBV). Idag är de flesta stolarna tillverkade utifrån lastbilskrav. Generellt är dessa stolar inte avsedda för den hårda skogsmiljön, särskilt de stora lateral- och rollrörelserna, och på grund av stora lateralkrafter går de ofta sönder efter en kort tids användning.För att bestämma det dynamiska beteendet och förbättra dagens stolar har en befintlig skotarstol, Be-Ge 3100 med Ponsses reglage och armstöd, analyserats. Vibrationstester genomfördes med hjälp en sex frihetsgraders vibrationsplattform. Samma stol utvärderades också med hjälp av simuleringar baserade på finita element metoden (FEM). Resultat från simuleringsmodellen har jämförts mot uppmätta resultat från vibrationsplattformen.Under vibrationstesterna på vibrationsplattformen, observerades det att den fritt rörliga delen i i upphängningsmekanismen vred sig längs de övre och nedre ramen med den följden att saxmekanismen böjde sig, vid rörelseexcitation i lateral riktning. Detta berodde på avsaknaden av lateral dämpning i stolen och det är förmodligen förklaringen till varför stolens saxmekanism går sönder efter en alltför kort tid. Generellt var stolens dynamiska rörelser från vibrationsplattformen och FEM-simuleringarna lika, men storleken på accelerationerna var lägre på grund av begränsningar i vibrationsplattformen.Baserat på FEM-modellen utvärderades förslag på ett nytt dämpsystem av fjädrar och dämpare. Analysen visar på att vibrationerna i sidled kan minskas och detta förslag bör vidareutvecklas i ett framtida arbete.In the forest, both operators and vehicles are suffering from high-level vibrations. A forwarder seat is one of the most significant units to isolate the vehicle operator from potentially hazardous whole-body vibrations (WBV). Nowadays, most of the forwarder seats are purchased from truck seats manufacturers. In general, those seats are not designed for the harsh forest environment, especially the large lateral and roll motions, and they frequently break after a short period of operation.In order to find the dynamic behavior and improve the seats to have longer life, an existing forwarder seat was analyzed. It was the Be-Ge 3100 seat with PONSSE machine manufacturer add-on parts. Physical vibration tests were performed with a six Degrees-of-Freedom (DOF) motion test platform. The same seat was also tested virtually, for the same condition, with Finite Element Analysis (FEA) simulations. This FEM (Finite Element Method) simulation model was verified with the physical test data.During the physical tests with excitation in the lateral direction, it was noticed that, the free moving rod ends in the suspension unit twisted along the upper and lower frame with bending motion on the scissors frame as well. This was due to the lack of lateral damping in the seat, and it is probably the explanation to why the base mechanism seat breaks after a too short period of operation. Generally, the seat dynamic motions got from physical tests and the FEM simulations were conceptually similar but the magnitudes differed due to the limitations in the Motion test platform.Relying on the verified FEM model, some concepts, with added lateral springs and dampers in the suspension unit, were proposed and analyzed. After FEA of the new concepts, the vibrations in the lateral direction were reduced and this concept can be detail designed in a future work.
40
Belobaba, Peter. "Air travel demand and airline seat inventory management." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14800.
41
Chavez, Miguel Angel 1979. "Design of a four-point seat-belt presenter." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/36104.
Анотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references.
The ambition of this thesis was to design and prototype a seat-belt presenter of a four-point seat-belt system for the Lear Corporation. The seat-belt presenter designed is to be implemented in automobile seats in order to facilitate putting a four-point seat belt. The worked perform is the culmination of both Petr Petri and myself in our efforts to find a method to properly present a four-point seat-belt system. The design utilizes a magnet at the end of an aluminum arm that is pivoted below a person's knee on the seat. A sensor detects when a person sits down and begins a series of actions to present the seat belt. The device uses a set of four mechanical sensors to locate the position of the arm, the seat belt, and on the seat to detect when a person sits down. A control system, which utilizes logic components, then decides what direction to turn the arm in and when to stop it. The prototype that was built to simulate the seat-belt presenter appears to work well but has little details that need to worked up before a product like this enters the market. Among the most important issues to be resolved is the prototyping of the second arm on the presenter, the mounting of the motor and sensors onto the mount, use of the appropriate sensors, and to address the problem of the electrical components overheating.
by Miguel Angel Chavez.
S.B.
42
Murphy, Moore Margot. "Happiness in the catbird seat : conversations with CEOs." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39512.
Анотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 2007.Includes bibliographical references (leaves 83-87).
Accomplished individuals should, by all modern definitions, be happy. They have achieved the power, authority, influence, and wealth that many in the American capitalist society aspire towards. But what defines happiness once you are there? When you are sitting in Thurber's proverbial "catbird seat," what is happiness? In conversations with 18 senior leaders of Fortune 1000 companies, guided by scripted questions posed by the author, the leaders responded to inquiries about their understanding of happiness, the influencers of happiness, the role of personal happiness in success, and their personal definition of happiness. The conversations, complemented by two standardized questionnaires, developed three thematic components of happiness. Social relationships, personal focus, and a sense of thresholds were revealed as the most consistent dimensions of personal happiness. These themes synthesize much of the existing literature on happiness where happiness is often divided into two definitions: eudonic: happiness derived from virtuosity, and hedonic: happiness derived from pleasure and the avoidance of pain. The conversations combined these theories and integrated life lessons from leadership to produce a theorem of sorts: Happiness exists in the enjoyment of virtuosity. Virtuous pain exists in vain.
by Margot Murphy Moore.
S.M.
43
Chen, Cenan, and Rong Fan. "Vehicle Seat Structure Play Analysis and Method Development." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-17251.
Анотація:
With the development of the vehicle industry and the innovation of technology, driving experience is improving in all aspects. Volvo is more and more focusing on improving the comfort of driving. Part of this is to minimize squeaks and rattle (S&R) from vehicle seats. A physical measurement method was studied from component level in this thesis. The communication with the supplier has helped to better understand the definition and measurement method of play. Based on the previous work from Volvo and the supplier, a new improved algorithm has been developed to suit current production demands in this thesis work. A Graphical User Interface (GUI) has been finished for general engineers. The Study and exploration of a FEM simulation method make it possible to measure play in an economical way in the future.
44
Reichert, Brian Anthony Jr. "Application of Magnetorheological Dampers for Vehicle Seat Suspensions." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/35884.
Анотація:
This study evaluates and provides solutions to the problem of poor subjective feel of seat suspensions that employ magnetorheological (MR) dampers and skyhook control. An Isringhausen seat suspension that had been modified to replace the stock passive damper with a controllable MR damper was used to evaluate the problems and potential solutions. A seat suspension tester was built using materials from 80/20 Incorporated and a hydraulic actuation system from MTS. An HP Dynamic Signal Analyzer was used as the main piece of data acquisition equipment, along with a Pentium PC and National Instruments Data Acquisition card. All of the hardware is installed in a controlled laboratory facility at Virginia Tech's Advanced Vehicle Dynamics Lab. The first task was to analyze the source of the unexpected peak in the acceleration spectrum of the suspended seat. This analysis was accomplished using a combination of pure tone inputs and a Fourier analysis of a simple model of the system. This analysis indicated that the peak is actually three times the resonant frequency of the seat suspension. The analysis also indicates that the frequency components continue at odd multiples of the resonant frequency, however, the third peak is the most noticeable. The third multiple is in the resonant frequency range (4-8 Hz) of the human body, so it was initially blamed for the poor subjective feel of the seat. However, solutions to remove this harmonic were tested without success.
The work progressed to a time domain analysis, which eventually led to determining the source of the poor subjective feel. The seat suspension was excited with a variety of inputs. The seat acceleration and damper control current were examined in the time domain to show that the cause of the poor subjective feel is the control signal discontinuities. The control policy was modified to remove the control signal discontinuities and was found to improve the subjective feel of the seat.
Finally, several two-degree-of-freedom control policies were implemented and tested. Although the results from this testing are inconclusive, they generated several recommendations for future research.
Master of Science
45
Seidel, Jared Colin. "Rear Seat Safety for Children in Frontal Impacts." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511970046224046.
46
Abdollahifakhr, Hamon, and Ceyhun Sengul. "AUTOMATIC DESIGN OF WIRING PATTERN FOR CAR SEAT HEATERS." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Maskinteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-13968.
Анотація:
This projects aims to develop design automation in product development. Design automation causes increase in producibility and decrease in product cost and manufacturing lead time. The study at hand is proposed to provide a new method and to introduce procedure to the design of wiring pattern for a car seat heater for Kongsberg Automotive, KA. KA is a Norwegian company and a global provider of engineering, design, and manufacture for seat comfort, driver and motion control systems, fluid assemblies, and industrial driver interface products. The method that currently is used in the company to create a wiring pattern is neither sufficient enough nor automated. In order to design the wiring pattern, at first procedure is handled by the designer. Secondly, car seat heater 2D layout is imported and then, the dimensions of the elements are defined as constraints. Then VBA codes are opened and the program is run. The result will be a wiring pattern in different 2D layouts. To make the design process easier, we have modeled five different layouts; wiring pattern of one element, two elements, three elements, five elements (with two back sides) and one element trapezoidal 2D layout. The algorithm written in VBA (Visual basic for application) creates the pattern according to the dimensions of the elements which are used as inputs to define constrained parameters. The created macros are simple to use and easy to modify, independent from the programming knowledge. The user is only responsible with parameter input and running the program. The solution gives wiring pattern for a car seat heater.
47
Rasmussen, David N. Ruegger Keith L. "A functional analysis of DoD implementation of seat management /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA371340.
Анотація:
Thesis (M.S. in Information Technology Management) Naval Postgraduate School, September 1999."September 1999". Thesis advisor(s): William James Haga, Matthew S. Feely. Includes bibliographical references (p. 87-89). Also Available online.
48
Hanaki-Martin, Saori. "THE EFFECTS OF SEAT POST ANGLE IN CYCLING PERFORMANCE." UKnowledge, 2012. http://uknowledge.uky.edu/khp_etds/1.
Анотація:
Triathlon involves three different modes of endurance events, swim, bike and run, consecutively. Transitions between events are critical to be successful in the sport; however, many triathletes report impaired running performance due to adverse residual effects from cycling. One of the strategies that triathletes use to manage the adverse effects is to use a bicycle with a more vertical seat post angle. There is limited evidence that support the effectiveness of such bicycle geometry, but many of these studies lacks ecological validity.
Twelve triathletes and cyclists completed a 20-km simulated course with instrumentations for 3D motion, kinetic, and electromyographic analyses under two different seat post angle settings: shallow (ROAD) and steep (TRI). Series of paired-t tests were used for statistical analysis.
Results indicated cycling mechanics between two seat post angle conditions were similar; however, the steep condition resulted in time-delay in muscle activation and pedal force application. There was no significant difference in cycling performance. The athletes were able to retain relatively consistent pedaling techniques with modification of seat post angle.
49
Rasmussen, David N., and Keith L. Ruegger. "A functional analysis of DoD implementation of seat management." Thesis, Monterey, California. Naval Postgraduate School, 1999. http://hdl.handle.net/10945/26566.
Анотація:
Approved for public release; distribution is unlimitedThis study explores the use of seat management as a method of overcoming the difficulty of procuring, managing and maintaining information technology. Seat management, also known as desktop outsourcing, involves the acquisition and management of all hardware and software, desktop and network management, operations management, support services and technology refreshment into one concise contract managed by a vendor who specializes in IT. The findings of this functional analysis, focusing on seat management, total cost of ownership and asset management, are reported. These findings show that seat management is not a panacea. But, when used in conjunction with sound management practices it can provide benefits to an organization
50
Gunston, Thomas Peter. "The sensitivity analysis of a suspension seat dynamic model." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274069.