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Journal articles on the topic 'Staircases'
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1
Wen, Ming, Hongxiang Tian, Weiwei Wang, Baokui Chen, and Huayao Fu. "Research on Seismic Performance of Frame Structure with Beam Staircases." Buildings 12, no. 8 (July 27, 2022): 1106. http://dx.doi.org/10.3390/buildings12081106.
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Beam staircases are widely used in frame structures. In structural design, stair flights are often ignored in the model establishment, and their loads are only added to the stair beams. However, under a seismic load, the flight of stairs will increase the staircase’s stiffness and affect the seismic response characteristics of the stairs and even of the structure. According to the engineering example, the finite element numerical models of the pure frame structure without staircases, the frame structure with fixed connection beam staircases, and the frame structure with sliding connection beam staircases were established. Modal analysis, response spectrum analysis, and elastic time-history analysis were carried out. By comparing the maximum story displacement, story displacement angle, natural period, story shear force, and the internal force of components of each model, the influences of beam staircases and their bearing connection mode on the seismic performance of the building were analyzed. In addition, by examining the frame model with sliding connection beam stairs, the influences of different staircase positions on the seismic performance of the building were studied. Finally, the advantages and disadvantages of different design schemes were compared, and the effects of the modeling method, support type, and layout position of the beam staircases on the seismic performance of the frame structure were summarized. The conclusions are that the story drift angle of the sliding connection structure is larger than that of the fixed connection structure, and the internal force of the frame columns of the former is smaller than that of the latter. Moreover, the positions of the staircase will affect the horizontal displacement of the structure.
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Shulman, Gordon L. "Attentional Modulation of a Figural Aftereffect." Perception 21, no. 1 (February 1992): 7–19. http://dx.doi.org/10.1068/p210007.
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Evidence is reported that indicates that adaptation of the Schroder staircase is affected by attention. In previous work it has been shown that if subjects adapt to an unambiguous staircase, responses to an ambiguous test figure are biased towards the opposing perspective. In the current work, subjects adapted to superimposed upright and inverted Schroder staircases. Both staircases were centered on a common fixation point and were of different sizes and colors. Attention to each staircase was controlled by asking subjects to detect color changes in the line segments that defined one or the other staircase. Responses to an ambiguous test figure depended on which of the adapting staircases was attended.
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Ramalingam, Balakrishnan, Rajesh Elara Mohan, Selvasundari Balakrishnan, Karthikeyan Elangovan, Braulio Félix Gómez, Thejus Pathmakumar, Manojkumar Devarassu, Madan Mohan Rayaguru, and Chanthini Baskar. "sTetro-Deep Learning Powered Staircase Cleaning and Maintenance Reconfigurable Robot." Sensors 21, no. 18 (September 18, 2021): 6279. http://dx.doi.org/10.3390/s21186279.
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Staircase cleaning is a crucial and time-consuming task for maintenance of multistory apartments and commercial buildings. There are many commercially available autonomous cleaning robots in the market for building maintenance, but few of them are designed for staircase cleaning. A key challenge for automating staircase cleaning robots involves the design of Environmental Perception Systems (EPS), which assist the robot in determining and navigating staircases. This system also recognizes obstacles and debris for safe navigation and efficient cleaning while climbing the staircase. This work proposes an operational framework leveraging the vision based EPS for the modular re-configurable maintenance robot, called sTetro. The proposed system uses an SSD MobileNet real-time object detection model to recognize staircases, obstacles and debris. Furthermore, the model filters out false detection of staircases by fusion of depth information through the use of a MobileNet and SVM. The system uses a contour detection algorithm to localize the first step of the staircase and depth clustering scheme for obstacle and debris localization. The framework has been deployed on the sTetro robot using the Jetson Nano hardware from NVIDIA and tested with multistory staircases. The experimental results show that the entire framework takes an average of 310 ms to run and achieves an accuracy of 94.32% for staircase recognition tasks and 93.81% accuracy for obstacle and debris detection tasks during real operation of the robot.
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Cho, HyeYoung, Amanda J. Arnold, Chuyi Cui, Zihan Yang, Tim Becker, Ashwini Kulkarni, Anvesh Naik, and Shirley Rietdyk. "Risky behavior during stair descent for young adults: Differences in men versus women." PLOS ONE 18, no. 7 (July 26, 2023): e0288438. http://dx.doi.org/10.1371/journal.pone.0288438.
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Injuries commonly occur on stairs, with high injury rates in young adults, especially young women. High injury rates could result from physiological and/or behavioral differences; this study focuses on behaviors. The purposes of this observational study were (1) to quantify young adult behaviors during stair descent and (2) to identify differences in stair descent behavior for young adult men versus women. Young adult pedestrians (N = 2,400, 1,470 men and 930 women) were videotaped during descent of two indoor campus staircases, a short staircase (2 steps) and a long staircase (17 steps). Behaviors during stair descent were coded by experimenters. Risky behaviors observed on the short staircase included: No one used the handrail, 16.1% used an electronic device, and 16.4% had in-person conversations. On the long staircase: 64.8% of pedestrians did not use the handrail, 11.9% used an electronic device, and 14.5% had in-person conversations. Risky behaviors observed more in women included: less likely to use the handrail (long staircase), more likely to carry an item in their hands (both staircases), more likely to engage in conversation (both staircases), and more likely to wear sandals or heels (both staircases) (p≤0.05). Protective behaviors observed more in women included: less likely to skip steps (both staircases), and more likely to look at treads during transition steps (long staircase) (p≤0.05). The number of co-occurring risky behaviors was higher in women: 1.9 vs 2.3, for men vs women, respectively (p<0.001). Five pedestrians lost balance but did not fall; four of these pedestrians lost balance on the top step and all five had their gaze diverted from the steps at the time balance was lost. The observed behaviors may be related to the high injury rate of stair-related falls in young adults, and young women specifically.
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Bebieva, Yana, and Mary-Louise Timmermans. "The Relationship between Double-Diffusive Intrusions and Staircases in the Arctic Ocean." Journal of Physical Oceanography 47, no. 4 (April 2017): 867–78. http://dx.doi.org/10.1175/jpo-d-16-0265.1.
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AbstractThe origin of double-diffusive staircases in the Arctic Ocean is investigated for the particular background setting in which both temperature and salinity increase with depth. Motivated by observations that show the coexistence of thermohaline intrusions and double-diffusive staircases, a linear stability analysis is performed on the governing equations to determine the conditions under which staircases form. It is shown that a double-diffusive staircase can result from interleaving motions if the observed bulk vertical density ratio is below a critical vertical density ratio estimated for particular lateral and vertical background temperature and salinity gradients. Vertical background temperature and salinity gradients dominate over horizontal gradients in determining whether staircases form, with the linear theory indicating that perturbations to stronger vertical temperature gradients are more likely to give rise to a staircase. Examination of Arctic Ocean temperature and salinity measurements indicates that observations are consistent with the theory for reasonable estimates of eddy diffusivity and viscosity.
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Ilyas, Muhammad, Anirudh Krishna Lakshmanan, Anh Vu Le, and Mohan Rajesh Elara. "Staircase Recognition and Localization Using Convolutional Neural Network (CNN) for Cleaning Robot Application." Mathematics 11, no. 18 (September 18, 2023): 3964. http://dx.doi.org/10.3390/math11183964.
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Floor-cleaning robots are primarily designed to clean on a single floor, while multi-floor environments are usually not considered target applications. However, it is more efficient to have an autonomous floor-cleaning robot that can climb stairs and reach the next floors in a multi-floor building. To operate in such environments, the ability of a mobile robot to autonomously traverse staircases is very important. For this operation, staircase detection and localization are essential components for planning the traversal route on staircases. This article describes a deep learning approach using a convolutional neural network (CNN)-based robot operation system (ROS) framework for staircase detection, localization, and maneuvering of the robot to the detected stair. We present a real-time object detection framework to detect staircases in incoming images. We also localize these staircases using a contour detection algorithm to detect the target point: a point close to the center of the first step, and an angle of approach to the target point with respect to the current location of the robot. Experiments are performed with data from images captured on different types of staircases at different viewpoints/angles. The experimental results show that the presented approach can achieve an accuracy of 95% and a recall of 86.81%. A total runtime of 155 ms is taken to identify the presence of a staircase and the detection of the first step in the working environment, as well as being able to locate the target point with an accuracy of ±2 cm, ±1 degree.
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Losada, M. Piacquadio, and S. Grynberg. "Cantor Staircases in Physics and Diophantine Approximations." International Journal of Bifurcation and Chaos 08, no. 06 (June 1998): 1095–106. http://dx.doi.org/10.1142/s0218127498000887.
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For a wide class of dynamical systems the variables involved relate to one another through a Cantor staircase function. When they are time variables, the staircases have well-known universal properties that suggest a connection with certain classical problems in Number Theory. In this paper we extend some of those universal properties to certain Cantor staircases that appear in Quantum Mechanics, where the variables involved are not time variables. We also develop some connections between the geometry of these Cantor staircases and the problem of approximating irrational numbers of rational ones, classical in Number Theory.
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Yang, Yang, Xiaodong Cai, Gang Yao, Meng Wang, Canwei Zhou, Ting Lei, and Yating Zhang. "Research on Intelligent Prefabricated Reinforced Concrete Staircase Lifting Point Setting Method Considering Multidimensional Spatial Constraint Characteristics." Sustainability 16, no. 14 (July 9, 2024): 5843. http://dx.doi.org/10.3390/su16145843.
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Prefabricated reinforced concrete staircases (PC staircases) are prefabricated components that are widely used in prefabricated buildings and are used in large quantities. During the production and construction of a PC staircase, the lifting point setting directly affects the construction safety, construction efficiency, and construction quality. In this paper, we analyze the quality problems and safety risks in the design, production, and construction of PC staircases under the constraints of multidimensional spatial characteristics, clarify the key technical difficulties of prefabricated staircase lifting under the multidimensional spatial and temporal constraints, and analyze the factors that should be considered in the setting of lifting points. In this paper, a prefabricated staircase lifting point setting database is established and a thin-plate spline interpolation algorithm is introduced to expand it. Based on the support vector machine algorithm, the process of optimization is carried out for the kernel function scale parameter and penalty factor, and it is concluded that for every increase of two in the number of cross-validation folds, the percentage reduction in minimum RMSE is 9.4%, 17.8%, and 4.2%, respectively, the percentage increase in the optimization time is 39.7%, 61.8%, and 27.3%, respectively, and a PC staircase lifting point setup method based on the small-sample database is proposed. The number of lifting points and lifting point locations of the PC staircase satisfying the multidimensional spatial feature constraints can be obtained by inputting the five design parameters of the PC staircase, namely, the number of treads, the height of the treads, the width of the treads, the width of the staircase, and the weight of the staircase, into the lifting point setup method proposed in this paper. The reliability of the precast reinforced concrete staircase lifting point setting method proposed in this paper when considering the multidimensional spatial constraint characteristics is verified by the precast staircases in deep shafts for assembly construction at the Chongqing metro station.
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Rollo, Callum, Karen J. Heywood, and Rob A. Hall. "Glider observations of thermohaline staircases in the tropical North Atlantic using an automated classifier." Geoscientific Instrumentation, Methods and Data Systems 11, no. 2 (October 25, 2022): 359–73. http://dx.doi.org/10.5194/gi-11-359-2022.
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Abstract. Thermohaline staircases are stepped structures of alternating thick mixed layers and thin high-gradient interfaces. These structures can be up to several tens of metres thick and are associated with double-diffusive mixing. Thermohaline staircases occur across broad swathes of the Arctic and tropical and subtropical oceans and can increase rates of diapycnal mixing by up to 5 times the background rate, driving substantial nutrient fluxes to the upper ocean. In this study, we present an improved classification algorithm to detect thermohaline staircases in ocean glider profiles. We use a dataset of 1162 glider profiles from the tropical North Atlantic collected in early 2020 at the edge of a known thermohaline staircase region. The algorithm identifies thermohaline staircases in 97.7 % of profiles that extend deeper than 300 m. We validate our algorithm against previous results obtained from algorithmic classification of Argo float profiles. Using fine-resolution temperature data from a fast-response thermistor on one of the gliders, we explore the effect of varying vertical bin sizes on detected thermohaline staircases. Our algorithm builds on previous work by adding improved flexibility and the ability to classify staircases from profiles with noisy salinity data. Using our results, we propose that the incidence of thermohaline staircases is limited by strong background vertical gradients in conservative temperature and absolute salinity.
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Radko, T., A. Bulters, J. D. Flanagan, and J. M. Campin. "Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases." Journal of Physical Oceanography 44, no. 5 (April 24, 2014): 1269–84. http://dx.doi.org/10.1175/jpo-d-13-0155.1.
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Abstract Three-dimensional dynamics of thermohaline staircases are investigated using a series of basin-scale staircase-resolving numerical simulations. The computational domain and forcing fields are chosen to reflect the size and structure of the North Atlantic subtropical thermocline. Salt-finger transport is parameterized using the flux-gradient formulation based on a suite of recent direct numerical simulations. Analysis of the spontaneous generation of thermohaline staircases suggests that thermohaline layering is a product of the gamma instability, associated with the variation of the flux ratio with the density ratio . After their formation, numerical staircases undergo a series of merging events, which systematically increase the size of layers. Ultimately, the system evolves into a steady equilibrium state with pronounced layers 20–50 m thick. The size of the region occupied by thermohaline staircases is controlled by the competition between turbulent mixing and double diffusion. Assuming, in accordance with observations, that staircases form when the density ratio is less than the critical value of , the authors arrive at an indirect estimate of the characteristic turbulent diffusivity in the subtropical thermocline.
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Meulemans, Lien, Evelien Van Roie, Jan Seghers, and Christophe Delecluse. "Older adults’ lower-limb muscle power production throughout a full flight of stairs: Reliability and comparison between different stair models." PLOS ONE 19, no. 2 (February 15, 2024): e0296074. http://dx.doi.org/10.1371/journal.pone.0296074.
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Lower-limb muscle power should be closely monitored to prevent age-related functional ability declines. Stair-climbing (SC) power is a functionally relevant measurement of lower-limb muscle power. Body-fixed sensors can measure power production throughout the different steps of a flight of stairs to assess different aspects of performance. This study investigated: 1) power production throughout a full flight of stairs; 2) if staircases with less or more steps can provide similar information; and 3) test-retest reliability of SC power. 116 community-dwelling older adults (57 women) ascended three staircases as fast as possible: 12, 6 and 3 steps. Mean vertical power production per step was collected and analyzed using a commercial body-fixed sensor and software. Three phases were found in SC power production: 1) an acceleration phase, i.e., the power produced in step 1 (P1); 2) a phase where the highest performance (Pmax) is reached and; 3) a fatiguing phase with power loss (Ploss; only measurable on 12-step staircase). Mean power (Pmean) over the different steps was also evaluated. P1 did not differ between staircases (all p>0.05), whereas Pmax and Pmean were higher with increasing number of steps (p = 0.073 –p<0.001). P1, Pmax and Pmean were strongly correlated between staircases (r = 0.71–0.95, p<0.05). and showed good to excellent reliability (ICC = 0.66–0.95, p<0.05). Ploss showed poor reliability. To conclude, measurements of SC power production (P1, Pmax and Pmean) with a single sensor on the lower back are reliable across different staircases. A small, transportable, 3-step staircase can be used for measuring power production in clinical practices with no access to regular staircases. However, absolute values are dependent on the number of steps, indicating that measurements to track performance changes over time should always be done using an identical stair model.
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WANG, XU-MING, SHI-XIAN QU, and DA-REN HE. "DISSONANCE OF MULTIPLE DEVIL'S STAIRCASES." International Journal of Bifurcation and Chaos 15, no. 05 (May 2005): 1677–87. http://dx.doi.org/10.1142/s021812740501282x.
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The multiple Devil's staircase reported by Qu, Wu and He in 1997 was composed of many tower-like structures. Each of which include two branches of the conventional complete Devil's staircases that connect the "single-exit" top and bottom steps. Their analytic conclusion show that all the conventional Devil's staircases are confined by two smooth curves with similar function forms W ∝ 1/ln ∊. These may be addressed as a kind of consonance. Our recent study found that it happens only in a few cases. Actually, in their system, 16 different kinds of tower branches exist in most parts of the parameter space. A lot of the steps lose the consonant property which are the so-called dissonant structures. The number of types of the corresponding dissonant branches is employed to describe the dissonance of the staircase. When the number of the discontinuous regions n, in the system develops, the dissonance of the staircase increases with 2n3- n rule. The numerical result shows that the conclusion is valid for a general discontinuous circle map.
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Dyment, SK. "Spiral Staircase Slides." Public 33, no. 66 (September 1, 2022): 103–15. http://dx.doi.org/10.1386/public_00124_7.
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The Spiral Staircase Slides image portrays a series of multi-storey residential homes with exterior staircases and balcony landings. In place of the iconic spiral staircases we see particularly in the architecture of Quebec and the Eastern Provinces, we see spiral slides of the sort found in children’s schoolyards. The image was a commentary on how some buildings are so ludicrously inaccessible they are comical, designed as if only able-bodied children need apply.
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Yang, Yantao, Wenyuan Chen, Roberto Verzicco, and Detlef Lohse. "Multiple states and transport properties of double-diffusive convection turbulence." Proceedings of the National Academy of Sciences 117, no. 26 (June 17, 2020): 14676–81. http://dx.doi.org/10.1073/pnas.2005669117.
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When fluid stratification is induced by the vertical gradients of two scalars with different diffusivities, double-diffusive convection (DDC) may occur and play a crucial role in mixing. Such a process exists in many natural and engineering environments. Especially in the ocean, DDC is omnipresent since the seawater density is affected by temperature and salinity. The most intriguing phenomenon caused by DDC is the thermohaline staircase, i.e., a stack of alternating well-mixed convection layers and sharp interfaces with very large gradients in both temperature and salinity. Here we investigate DDC and thermohaline staircases in the salt finger regime, which happens when warm saltier water lies above cold fresher water and is commonly observed in the (sub)tropic regions. By conducting direct numerical simulations over a large range of parameters, we reveal that multiple equilibrium states exist in fingering DDC and staircases even for the same control parameters. Different states can be established from different initial scalar distributions or different evolution histories of the flow parameters. Hysteresis appears during the transition from a staircase to a single salt finger interface. For the same local density ratio, salt finger interfaces in the single-layer state generate very different fluxes compared to those within staircases. However, the salinity flux for all salt finger interfaces follows the same dependence on the salinity Rayleigh number of the layer and can be described by an effective power law scaling. Our findings have direct applications to oceanic thermohaline staircases.
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Bogusławska, Arleta, and Dorota Brzezińska. "The Impact of Outdoor Temperatures on the Efficacy of Natural Ventilation and Smoke Exhaust Systems." Energies 15, no. 3 (January 27, 2022): 933. http://dx.doi.org/10.3390/en15030933.
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Natural smoke control systems in staircases are one of the available systems used for the protection of escape routes from smoke and are one of the most utilised for medium to high rise buildings. However, their effectiveness (as well as other ventilation systems) is strongly dependent on the weather conditions, especially the outdoor temperature. This paper describes the results of real-scale experiments of the airflow in a staircase’s natural smoke exhaust system. The experimental staircase was localised in a medium-high building, “LabFactor” at the Lodz University of Technology in Poland. The experiments were performed over a period of six months, from February to July 2019, and included measurements of external and internal air temperature as well as the airflow through the staircase. The results obtained enabled an evaluation of the effectiveness of the ventilation and natural smoke exhaust system in the staircase, in relation to external temperatures. It was found that natural smoke exhaust systems could operate below an acceptable level of effectiveness for nearly 25% of the year. The experimental results were confirmed with CFD simulations.
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Breen, Marilyn. "A Krasnosel’skii-type theorem for certain orthogonal polytopes starshaped via k-staircase paths." Advances in Geometry 20, no. 2 (April 28, 2020): 169–77. http://dx.doi.org/10.1515/advgeom-2019-0018.
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AbstractLet 𝒞 be a finite family of distinct axis-parallel boxes in ℝd whose intersection graph is a tree, and let S = ⋃{C : C in 𝒞}. If every two points of S see a common point of S via k-staircase paths, then S is starshaped via k-staircase paths. Moreover, the k-staircase kernel of S will be convex via k-staircases.
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Benkouda, Hassina, Samira Louafi, and Ammar Mebarki. "Enhancing visual comfort in staircases: A comprehensive analysis and design recommendations." Architecture Papers of the Faculty of Architecture and Design STU 29, no. 2 (June 1, 2024): 30–44. http://dx.doi.org/10.2478/alfa-2024-0010.
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Abstract People should be walking towards the inside of the dwelling through an appropriate visual environment in transitional space; this environment is the staircase in the collective housing. The proper understanding of visual adaptation parameters in the staircase helps architects provide a suitable environment for inhabitants. This paper aims to specify design elements of the staircase in collective housing, to achieve a visual comfort in this transitional space. The work involved two approaches: field measurements and a visual comfort survey using a questionnaire; 144 questionnaires are collected, in four residential buildings with different staircases treatment in the city of Arris, Algeria, to examine the illuminance levels in different staircase positions along the path from outside the building to inside, in summer and winter where illuminance ratios were calculated and compared with CIBSE Code. The discomfort sensations ranged from "subtle” to "dramatic”. The results show that a staircase with the percentage of opening of 88% indicated "strong" and "dramatic" visual shock in many points and as this staircase is open, it is exposed to light conditions and so it does not ensure the necessary transition. This leads to advising against the open staircase. In the case of a staircase treated with transoms of clear glass with the percentage of opening of 11%, these transoms direct the light to specific areas creating "strong" visual shock in many points of the stair landings and hence it leads to advise against that. The staircases treated with vertical bays throughout the façade presenting a percentage of opening between 19% and 22%, these treatments allow the penetration of daylight in a diffused way which ensures a balanced distribution of daylight inside the staircases. The existence of a solid overhang at the entrance; the façade treated with vertical bays, where the percentage of opening of the façade is about 19% and 22%, provided adequate transition leading to reasonable visual comfort.
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LOSADA, M. PIACQUADIO. "THE GEOMETRY OF FAREY STAIRCASES." International Journal of Bifurcation and Chaos 14, no. 12 (December 2004): 4075–96. http://dx.doi.org/10.1142/s0218127404011855.
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We study Cantor staircases arising from different problems in Physics. Each staircase is endowed with the Farey structure in the vertical axis, the underlying cantordust set Ω having a fractal dimension strictly between 0 and 1. We find that length and distribution of stairsteps follow hyperbolic laws related to the Poincaré measure in the hyperbolic half-plane. The geometry of the underlying Ω is studied with the same tools.
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van der Boog, Carine G., J. Otto Koetsier, Henk A. Dijkstra, Julie D. Pietrzak, and Caroline A. Katsman. "Global dataset of thermohaline staircases obtained from Argo floats and Ice-Tethered Profilers." Earth System Science Data 13, no. 1 (January 13, 2021): 43–61. http://dx.doi.org/10.5194/essd-13-43-2021.
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Abstract. Thermohaline staircases are associated with double-diffusive mixing. They are characterized by stepped structures consisting of mixed layers of typically tens of metres thick that are separated by much thinner interfaces. Through these interfaces enhanced diapycnal salt and heat transport take place. In this study, we present a global dataset of thermohaline staircases derived from observations of Argo profiling floats and Ice-Tethered Profilers using a novel detection algorithm. To establish the presence of thermohaline staircases, the algorithm detects subsurface mixed layers and analyses the interfaces in between. Of each detected staircase, the conservative temperature, absolute salinity, depth, and height, as well as some other properties of the mixed layers and interfaces, are computed. The algorithm is applied to 487 493 quality-controlled temperature and salinity profiles to obtain a global dataset. The performance of the algorithm is verified through an analysis of independent regional observations. The algorithm and global dataset are available at https://doi.org/10.5281/zenodo.4286170.
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Good, Robert. "Double staircases and the vertical distribution of housing in Venice 1450–1600." Architectural Research Quarterly 13, no. 1 (March 2009): 73–86. http://dx.doi.org/10.1017/s135913550999011x.
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This paper presents changes in the vertical circulation and organisation of merchant palaces, and their influence on multi-family architecture in Venice from 1450 to 1600. Just prior to this period buildings underwent a substantial change in the vertical distribution of floors; this marked the transfer of the commercial-residence casa fondaco prototype into a more complex multi-level building with two semi-autonomous piani nobili palatial apartments. The resulting vertical expansion led to a departure away from the external courtyard staircase as the primary means of vertical circulation. Many Late Gothic palatial buildings incorporated double courtyard staircases that provided individual access to each palatial apartment. However, this scheme consumed a great deal of developable land resulting in the widespread utilisation of interior monumental dog-leg staircases by the Early Renaissance. This simplified internal staircase fitted cleanly into the existing structural logic of both new and remodelled palace buildings.
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Hu, Min, and Wei Cai. "Simulation and Optimization for the Staircase Evacuation of a Cruise Ship Based on a Multigrid Model." Mathematical Problems in Engineering 2021 (May 15, 2021): 1–18. http://dx.doi.org/10.1155/2021/9961536.
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A cruise ship is a large public place, and it is very important to ensure the safety of passengers during the evacuation process in case of an emergency. This paper proposes a method to improve evacuation efficiency on cruise ships by controlling passengers’ density. According to the construction of the staircase, the space of the staircase is divided into the step and landing areas. On the basis of considering the influence of passengers’ view field and moving characteristics of passengers, the moving rules of passengers in two areas are established. Taking staircases of the cruise ship as the evacuation scenario, the evacuation process is simulated by using the established model. From simulation results, it is found that numbers of evacuated passengers between staircases are very unbalanced and too many passengers gather in one staircase, which lead to serious congestion. By controlling passengers’ density in stairs areas, the minimum evacuation time is the optimization objective and the optimization model is established by using the quantum-inspired evolutionary algorithm and genetic algorithm. The optimization results show that the evacuation time is significantly shortened when the passenger’s density on the staircase is kept within an appropriate range, which proves that the evacuation efficiency can be effectively improved by controlling the passengers’ density.
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Vorochaeva, Lyudmila, Sergey Savin, and Andrey Mal'chikov. "INVESTIGATION OF STAIR FLIGHT OVERCOMING BY JUMPING ROBOT." Bulletin of Bryansk state technical university 2020, no. 2 (February 6, 2020): 53–61. http://dx.doi.org/10.30987/1999-8775-2020-2020-2-53-61.
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In the paper there is considered a stair flight overcoming by a wheel jumping robot during lifting upon it. The robot consists of a casing, an accelerating module ensuring device separation from a surface and a wheel platform at the expense of which a robot moves on even surfaces and it is positioned in front of a stair flight. The latter is characterized with the footstep number, a length and a height of each footstep that defines the number of robot jumps (from one up to footstep number), and also a height and a length of each jump.
In the work there are introduced and described basic parameters of a stair flight, jump characteristics and also the limitations imposed upon a rate of robot separation from a surface and an angle of a slope of its vector and specified by staircase parameters. As qualitative criteria of the stair flight overcoming are energy and time spent at that. As a result of the computational modeling it is determined that at stair flight jumping over in a single bound the required rate of separation of the jumping robot from a surface and also energy and time spent for a jump increase with the growth of the staircase number in the stair flight at that a rate and time – according to curvilinear laws, and energy – proportionally to the number of staircases in the stair flight. Besides, there are investigated six versions for jumping robot to overcome stair flights with the different number of staircases, at that the number of staircases to jump over in a single bound at each version of jump series fulfillment is equal. At that there is no clear regularity between energy and the number of jumps carried out (and staircases to jump over) and time spent increases with the increase of the jump number. The optimization of jumping robot motion on a stair flight from the point of view of the minimization of time and energy consumption is carried out as a result of which the necessity to overcome a staircase in one bound irrespective of the number of footsteps is carried out.
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Cohen, Joseph, and H. Harvey Cohen. "Hold On! An Observational Study of Staircase Handrail Use." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 45, no. 20 (October 2001): 1502–6. http://dx.doi.org/10.1177/154193120104502013.
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Handrails are the primary safety devices installed on staircases, yet it has not been empirically determined to what extent they are actually used. This study selected two staircases, one long and wide and another short and narrow, serving a newly remodeled shopping mall. Variables observed were: handrail use, ascent/descent, number of hands free, within arm's reach, gait, gender, and age. Less than a third of all staircase users utilized a handrail, with the likelihood of use increasing with age. Overall, 59% were observed to place themselves within arm's reach of a handrail. Staircase users were more likely to be within arm's reach during descent. Women were more likely to have just one hand free, while men more frequently had both hands free. Handrail use was observed to be 10% greater during descent than ascent. The study shows that even with handrails having high usability characteristics, actual handrail use is minimal. This finding has implications for behavioral compliance in situations where a safety device is provided, but its need is not perceived to be immediate.
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Mohammad, Ilyas, Aamir Hayat Abdullah, Veerazhagadheswar Prabhakaran, and Rajesh Elara Mohan. "3D Absolute pose estimation of a staircase cleaning robot utilizing staircase geometry and minimal low-cost sensors." Herald of the Kazakh-British technical university 20, no. 4 (December 12, 2023): 27–39. http://dx.doi.org/10.55452/1998-6688-2023-20-4-27-39.
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Thanks to its shape-shifting abilities, the sTetris robot can climb stairs while performing the cleaning task. The sTetris robot’s overall system operation depends on localization and positioning data, which are essential for its goal of autonomously navigating multi-floor environments. The mobile robots designed to work indoors generally rely on external systems for localization information. Regretfully, this frequently requires additional hardware fixing or changes to the indoor working environment in order to achieve accurate three-dimensional (3D) position and orientation (pose) for successful operation of the mobile platform. Nonetheless, the robot can be localized on the staircase by utilizing the information of the staircase’s geometry measurements, which are known ahead of time. This article demonstrates how the known geometry of staircases and measurements from minimal number of sensors can be used to accomplish 3D pose of the robot. Experiments carried out on a real robot in an authentic indoors setting successfully demonstrate the effectiveness of the suggested approach.
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Price, Sam. "Cantilevered staircases." Architectural Research Quarterly 1, no. 3 (1996): 76–87. http://dx.doi.org/10.1017/s1359135500002931.
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This paper describes the structural principles of cantilevered staircases. A brief history is given of stone staircases built in England, and a number of particularly interesting examples are discussed in detail. Four new staircases, built during the last decade, are described, demonstrating the relevance of these long established principles to contemporary construction.
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Hoover, Eric C. "Accurately targeting an arbitrary probability of response in staircase procedures." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A223. http://dx.doi.org/10.1121/10.0011127.
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Staircase procedures are commonly used to identify the stimulus level corresponding to a specific probability of response. The primary benefit of staircase procedures is that they require only that the probability of response changes monotonically with the stimulus level. The probability of response targeted by the procedure is typically estimated from the mean of reversals. However, the mean of reversals can be asymptotically biased away from the targeted probability. Existing methods to address the bias add assumptions about task performance, thereby limiting their use to well understood tasks and listener groups. We evaluated the hypothesis that the bias could be mitigated without adding assumptions by accounting for the effect of invariant procedural parameters on the estimate of the target probability. The approach was successful for staircases with different ascending and descending steps, for which the bias was found to depend on step size only. For other staircases, predicting bias required adding assumptions comparable to existing solutions. Results suggest that the bias is caused by the factthat reversals are influenced by parameters that do not affect the target point. A method is proposed to accurately estimate an arbitrary probability of response without adding assumptions about the task or listeners. [R01DC015051.]
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Radko, T., J. D. Flanagan, S. Stellmach, and M. L. Timmermans. "Double-Diffusive Recipes. Part II: Layer-Merging Events." Journal of Physical Oceanography 44, no. 5 (April 24, 2014): 1285–305. http://dx.doi.org/10.1175/jpo-d-13-0156.1.
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Abstract This study explores the dynamics of thermohaline staircases: well-defined stepped structures in temperature and salinity profiles, commonly observed in regions of active double diffusion. The evolution of staircases in time is frequently characterized by spontaneous layer-merging events. These phenomena, the authors argue, are essential in regulating the equilibrium layer thickness in fully developed staircases. The pattern and mechanics of merging events are explained using a combination of analytical considerations, direct numerical simulations, and data analysis. The theoretical merger model is based on the stability analysis for a series of identical steps and pertains to both forms of double diffusion: diffusive convection and salt fingering. The conceptual significance of the proposed model lies in its ability to describe merging events without assuming from the outset specific power laws for the vertical transport of heat and salt—the approach adopted by earlier merging models. The analysis of direct numerical simulations indicates that merging models based on the four-thirds flux laws offer adequate qualitative description of the evolutionary patterns but are less accurate than models that do not rely on such laws. Specific examples considered in this paper include the evolution of layers in the diffusive staircase in the Beaufort Gyre of the Arctic Ocean.
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Menga, Giuseppe. "A Novel Paradigm for Controlling Navigation and Walking in Biped Robotics." Electronics 13, no. 11 (June 6, 2024): 2224. http://dx.doi.org/10.3390/electronics13112224.
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This paper extends the three-dimensional inverted pendulum (spherical inverted pendulum or SIP) in a polar coordinate system to simulate human walking in free fall and the energy recovery when the foot collides with the ground. The purpose is to propose a general model to account for all characteristics of the biped and of the gait, while adding minimal dynamical complexity with respect to the SIP. This model allows for both walking omnidirectionally on a flat surface and going up and down staircases. The technique does not use torque control. However, for the gait, the only action is the change in angular velocity at the start of a new step with respect to those given after the collision (emulating the torque action in the brief double stance period) to recover from the losses, as well as the preparation of the position in the frontal and sagittal planes of the swing foot for the next collision for balance and maneuvering. Moreover, in climbing or descending staircases, during the step, the length of the supporting leg is modified for the height of the step of the staircase. Simulation examples are offered for a rectilinear walk, ascending and descending rectilinear or spiral staircases, showing stability of the walk, and the expenditure of energy.
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Webb, Oliver J., and Frank F. Eves. "Effects of Environmental Changes in a Stair Climbing Intervention: Generalization to Stair Descent." American Journal of Health Promotion 22, no. 1 (September 2007): 38–44. http://dx.doi.org/10.4278/0890-1171-22.1.38.
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Purpose. Visual improvements have been shown to encourage stair use in worksites independently of written prompts. This study examined whether visual modifications alone can influence behavior in a shopping mall. Climbing one flight of stairs, however, will not confer health benefits. Therefore, this study also assessed whether exposure to the intervention encouraged subsequent stair use. Design. Interrupted time-series design. Settings. Escalators flanked by a staircase on either side. Subjects. Ascending and descending pedestrians (N = 81,948). Interventions. Following baseline monitoring, a colorful design was introduced on the stair risers of one staircase (the target staircase). A health promotion message was superimposed later on top. The intervention was visible only to ascending pedestrians. Thus, any rise in descending stair use would indicate increased intention to use stairs, which endured after initial exposure to the intervention. Measures. Observers inconspicuously coded pedestrians' means of ascent/descent and demographic characteristics. Results. The design alone had no meaningful impact. Addition of the message, however, increased stair climbing at the target and nontarget staircases by 190% and 52%, respectively. The message also produced a modest increase in stair descent at the target (25%) and nontarget (9%) staircases. Conclusions. In public venues, a message component is critical to the success of interventions. In addition, it appears that exposure to an intervention can encourage pedestrians to use stairs on a subsequent occasion.
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Jiang, Huan Jun, Hai Yan Gao, and Bin Wang. "Seismic Damage Analyses of Staircases in RC Frame Structures." Advanced Materials Research 446-449 (January 2012): 2326–30. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.2326.
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Staircases in Reinforced Concrete (RC) frame structures suffered severe damages in recent earthquakes although they are regarded as critically important passages during emergencies. Staircases act as the first line of defense in earthquakes, and therefore they first yield and fail. Then they lose the action of safe passages so that the anticipated seismic performance objectives cannot be satisfied. To make sure that staircases work as safe passages in strong earthquakes, the current Chinese code for seismic design of buildings claims special requirements on the design of staircases. At first, the influence of staircases on the structural behavior of a typical RC frame structure is studied by the comparison of internal force in the structural members considering and neglecting the effect of staircases under frequent earthquakes. Besides, the effect of staircases on the yielding and failing mechanism of the frame structure is investigated through static elasto-plastic analyses. From this study the reason of the damages suffered by cast-in-site staircases in RC frame structures under earthquakes can be understood.
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Chen, Yan. "Process of Baluster for Stone Spiral Staircase." Advanced Materials Research 823 (October 2013): 636–39. http://dx.doi.org/10.4028/www.scientific.net/amr.823.636.
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In modern cities, with the rapid development of economy, various stone spiral staircases were decorated by more and more hotels or guest houses. It was very popular and showed beautiful decoration design style of modern hotel. In this paper, we studied the design process of baluster from stone spiral staircase. A new technical process for baluster of spiral staircase was investigated. We found much flaws of spiral surface in process of stone staircase and calculated a series of formulas by digital control of bead or wire saw. And one-time-molding techniques will be used in pieces processing. By sample analysis, this new method is more convenient than before. We believe that this stone spiral staircase will be used by more construction in the future.
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Umlauf, Lars, Peter L. Holtermann, Christiane A. Gillner, Ralf D. Prien, Lucas Merckelbach, and Jeffrey R. Carpenter. "Diffusive Convection under Rapidly Varying Conditions." Journal of Physical Oceanography 48, no. 8 (August 2018): 1731–47. http://dx.doi.org/10.1175/jpo-d-18-0018.1.
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AbstractIn most observations of diffusive convection in the ocean and in lakes, the characteristic diffusive staircases evolve over long time scales under quasi-stationary background conditions. In the Baltic Sea, however, diffusive staircases develop inside the flanks of intermittent intrusions that induce strong inverse temperature gradients over a vertical range of a few meters, varying on time scales of hours to days. Here, results are discussed from an extensive field campaign conducted in summer 2016 in the southern Baltic Sea, including temperature microstructure data from ocean gliders and an autonomous profiling platform. We find conditions favorable for diffusive instability in the vicinity of warm and cold intrusions with density ratios as small as Rρ = 1.3. The staircases evolving under these conditions are characterized by a small number of steps (typically 1–4) with order 0.1–1-m thickness, temperature differences exceeding 1 K across individual diffusive interfaces, and exceptionally large diffusive heat fluxes of order 10 W m−2. The standard heat flux parameterization of Kelley agrees within a factor of 2 with the directly observed interfacial heat fluxes, except for large fluxes at low Rρ, which are strongly overestimated. The glider surveys reveal a surprisingly small lateral coherency of order 100 m of the staircase patterns, and a spreading of the diffusively unstable intrusions across isopycnals.
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Seo, Janghoon, Hogun Jhang, and Jae-Min Kwon. "Effects of light impurities on zonal flow activities and turbulent thermal transport." Physics of Plasmas 29, no. 5 (May 2022): 052502. http://dx.doi.org/10.1063/5.0086587.
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Nonlinear effects of light impurities on the zonal flow activities and electrostatic ITG (ion temperature gradient) mode are investigated with gyrokinetic simulations. For the investigation, a new multiple-ion-species gyrokinetic Poisson solver is implemented numerically. Benchmark tests for the new solver show good agreements with theoretical and previous simulation results. Nonlinear ITG simulations with and without light impurities are compared. To isolate nonlinear effects of impurities on ITG, simulation parameters are set to exhibit approximately identical spectra of linear growth rates for the admixed and pure deuterium cases (i.e., the cases with and without the impurities). With an intermediate safety factor (∼1.4), the admixed case shows smaller heat transport and more robust E × B staircase structures than the pure deuterium case. The locations of the transport suppression and staircases are strongly correlated, which indicate that light impurities have stabilizing effects on ITG by enhancing the staircase-like E × B shearing. Especially, the radial correlation length of the fluctuations is significantly reduced for the admixed case. On the other hand, the stabilizing effect of impurities is weakened with a high safety factor (∼5). In those cases, strong geodesic acoustic mode activity is observed, and the electric field is dominated by oscillating components instead of stationary staircases.
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Rajcic, Aleksandar, Ana Radivojevic, and Martin Elezovic. "Correlation between the morphology of unheated staircase and energy performance of residential buildings." Thermal Science 19, no. 3 (2015): 845–56. http://dx.doi.org/10.2298/tsci130703011r.
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As a side effect of the need for greater energy efficiency of buildings, there is a problem of decrease of the available interior space affected by the reduction in U-value of parts of thermal building envelope, i.e. an increase in thickness of insulating layer, which is especially present in unheated staircase. Having in mind that present methods of calculation of transmission heat losses through elements of thermal envelope include the adjustment factor which regulates designed temperature conditions if the temperature at the colder side of the element of the thermal envelope differs from that of the external environment, this paper strives to demonstrate that in the case of unheated staircases, this fixed value should be reconsidered and treated as a variable depending on the morphology, i.e. form, size and position of the staircase within the building. This problem has been analyzed on the example of Serbian housing stock and relevant national thermal regulations. Three morphological types of unheated staircases have been distinguished within which three models have been defined and examined with respect to variations in number of floors and percentage of glazing. Average temperatures of staircase volume and temperature correction factors were calculated in following temperature modes: stationary that excluded solar gains and ventilation heat losses and gains, and dynamic with variations in air exchange rates and insolation conditions, expressing in all of the cases variations in calculated values of temperature correction factors in comparison to the prescribed fixed value.
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Quin Jr., Franklin, Tamara Franca, Jason Street, Hyungsuk Lim, and Rubin Shmulsky. "Structural performance of connectors in a hardwood stairway handrail guard system." BioResources 19, no. 1 (January 10, 2024): 1410–32. http://dx.doi.org/10.15376/biores.19.1.1410-1432.
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Wood is a preferred material for constructing staircases due to its appealing aesthetic features. The use of wood, especially hardwoods such as red oak (Quercus rubra), white oak (Quercus alba), yellow poplar (Liriodendron tulipifera), and hard maple (Acer saccharum), has been the main construction material for staircases over the years. Staircase designs have evolved because of the flexibility of wood and working with specialized manufacturing machinery. A stair guard system connection must be designed to resist rotational and translational movements whenever a force is applied to the handrail. The demand for structural design values in wooden stair guards has been steadily increasing, driven by the needs of engineers, designers, builders, and end-users alike. This paper presents experimental data for four stair guard connections (post-to-rail, infill-to-footing, infill-to-rail, and rail-to-rail) encountered in a hardwood stairway handrail guard system. The data generated from this research could be useful for modeling the structural behavior of the connections.
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Morell, Julio M., Jorge E. Corredor, and William J. Merryfield. "Thermohaline staircases in a Caribbean eddy and mechanisms for staircase formation." Deep Sea Research Part II: Topical Studies in Oceanography 53, no. 1-2 (January 2006): 128–39. http://dx.doi.org/10.1016/j.dsr2.2005.09.013.
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PIVKA, LADISLAV, ALEXANDER L. ZHELEZNYAK, and LEON O. CHUA. "ARNOL’D TONGUES, DEVIL’S STAIRCASE, AND SELF-SIMILARITY IN THE DRIVEN CHUA’S CIRCUIT." International Journal of Bifurcation and Chaos 04, no. 06 (December 1994): 1743–53. http://dx.doi.org/10.1142/s0218127494001350.
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Empirical recurrent relations, governing the structure of the devil’s staircase in the driven Chua’s circuit are given, which reflect the self-similar structure in an algebraic form. In particular, it turns out that the same formulas hold for both winding and period numbers, but with different “initial conditions”. Some of the finer details such as period-doubling along with numerous coexistence phenomena within staircases of mode-locked states have been revealed by computing high-resolution bifurcation diagrams.
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Lin, Zhiyu, Shengbin Hu, and Hang Lin. "Flow Pattern and Escape Hazards of People from Flood Intrusion into the Staircase of Underground Spaces with Multiple Rest Platforms." Buildings 14, no. 4 (March 29, 2024): 941. http://dx.doi.org/10.3390/buildings14040941.
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While urban underground space is being built and developed at a high speed, urban flooding is also occurring gradually and frequently. Urban water, in many disasters, has intruded into underground spaces, such as subway stations, often leading to serious casualties, in which it is crucial for people to be able to escape from the staircases. In order to enable and guide the escape of people in underground floods, a staircase model with multiple rest platforms, applicable to common entrance and exit staircase forms, was constructed. The realizable k-ε turbulence model, coupled with a volume of fluid (VOF) method, was used to simulate and analyze the flow patterns when floods of various heights intrude into the structure. The effects of rest platform settings on the ejection phenomena and flow velocity changes in flood flows were summarized. The change rule of flood flow velocity on the stairs under different flood heights and stair heights was summarized, and a linear relationship between the peak flood flow velocity and the location of the peak flow velocity point on each flight of stairs was derived. Combined with the formula of the critical conditions for people to escape upwards in the flood, the proposed escape conditions for staircases with multiple rest platforms were proposed, which provide a basis for guiding the evacuation of people in times of disaster.
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Nespěšný, Ondřej, David Bečkovský, Jan Vystrčil, Vojtěch Vaněk, Miloslav Novotný, and Jan Pěnčík. "Experimental Loading of Staircase Made from Cement Fiber Boards with Cellulose Fibers Using Full-Scale Model." Buildings 13, no. 3 (March 7, 2023): 704. http://dx.doi.org/10.3390/buildings13030704.
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The study presents a possible innovative use of cement fiber boards (CFBs) reinforced with cellulose fibers for construction of an interior prefabricated staircase. Regarding the unusual use of traditional material that was used in all bearing elements of the staircase, a numerical simulation with the use of a material model SBETA was carried out and, subsequently, multiple experimental static loading was applied. In order to carry out experimental testing of static load capacity, a full-scale experiment method was chosen and performed on a real staircase structure for family houses. The full-scale experiment is considered the most precise method to test structures or material behavior. The obtained results show that the designed and tested staircase structure of CFBs is able to meet the requirements of technical standards related to static loading of staircases. The load test confirmed the potential use of cement fiber boards produced by the Hatschek process for real bearing structures under static loading.
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Purnama, Indra, M. Shane Waafi, Rikho Ardiyan Dwicahyo, and Ari Zaqi Al-Faritsy. "Peramalan Penjualan Produk Teralis Besi Menggunakan Metode ARIMA: Studi Kasus Bengkel Las Bale Karya." ARZUSIN 4, no. 3 (May 14, 2024): 464–71. http://dx.doi.org/10.58578/arzusin.v4i3.2965.
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Bengkel Las Bale Karya is one of the small and medium-sized enterprises (SMEs) that produces various types of iron crafts such as seesaws, swings, staircase railings, balcony railings, spiral staircases, iron doors, grilles, fence doors, and others. This research focuses on the production of iron grille products. The research method employed in this study is the ARIMA method for forecasting over the next 12 periods. The results of this study aim to optimize iron grille production to prevent product stockpiling, ensure material availability, and enhance workplace safety.
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Hadi, Sz, and A. S. Kis. "Structural Analysis of Historical Cantilevered Stone Staircases." Journal of Applied Engineering Sciences 13, no. 2 (December 1, 2023): 197–206. http://dx.doi.org/10.2478/jaes-2023-0025.
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Abstract This paper studies the behaviour of historical cantilevered stone staircases. In Transylvania these types of stairs are found mainly in buildings classified as historical monuments built until the 1920s. Understanding the behaviour of historical staircases is essential when proposing consolidation or restoration interventions in buildings. In this work, structural analyses on simple models of staircases made of stone elements are proposed in order to investigate the stiffness of the assembly, the stresses that appear in the elements, deformations, the influence of the railings in the overall behaviour and the simulation of the breaking of a single individual step. The types of staircases investigated in this paper are existing historical structures that currently are no longer built from scratch, so the purpose of the calculation is not to dimension but to verify the existing structure.
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STELLMACH, S., A. TRAXLER, P. GARAUD, N. BRUMMELL, and T. RADKO. "Dynamics of fingering convection. Part 2 The formation of thermohaline staircases." Journal of Fluid Mechanics 677 (May 4, 2011): 554–71. http://dx.doi.org/10.1017/jfm.2011.99.
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Regions of the ocean's thermocline unstable to salt fingering are often observed to host thermohaline staircases, stacks of deep well-mixed convective layers separated by thin stably stratified interfaces. Decades after their discovery, however, their origin remains controversial. In this paper we use three-dimensional direct numerical simulations to shed light on the problem. We study the evolution of an analogous double-diffusive system, starting from an initial statistically homogeneous fingering state, and find that it spontaneously transforms into a layered state. By analysing our results in the light of the mean-field theory developed in Part 1 (Traxler et al., J. Fluid Mech. doi:10.1017/jfm.2011.98, 2011), a clear picture of the sequence of events resulting in the staircase formation emerges. A collective instability of homogeneous fingering convection first excites a field of gravity waves, with a well-defined vertical wavelength. However, the waves saturate early through regular but localized breaking events and are not directly responsible for the formation of the staircase. Meanwhile, slower-growing, horizontally invariant but vertically quasi-periodic γ-modes are also excited and grow according to the γ-instability mechanism. Our results suggest that the nonlinear interaction between these various mean-field modes of instability leads to the selection of one particular γ-mode as the staircase progenitor. Upon reaching a critical amplitude, this progenitor overturns into a fully formed staircase. We conclude by extending the results of our simulations to real oceanic parameter values and find that the progenitor γ-mode is expected to grow on a time scale of a few hours and leads to the formation of a thermohaline staircase in about one day with an initial spacing in the order of 1–2 m.
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Troubetzkoy, Serge. "Recurrence in generic staircases." Discrete & Continuous Dynamical Systems - A 32, no. 3 (2012): 1047–53. http://dx.doi.org/10.3934/dcds.2012.32.1047.
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Bougard, A. "Human loading on staircases." Proceedings of the Institution of Civil Engineers - Structures and Buildings 152, no. 4 (November 2002): 371–80. http://dx.doi.org/10.1680/stbu.2002.152.4.371.
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Kara, Melike, Cheryl L. Eames, Amanda L. Miller, and Annie Chieu. "Staircases, Towers, and Castles." Mathematics Teacher 108, no. 9 (May 2015): 663–70. http://dx.doi.org/10.5951/mathteacher.108.9.0663.
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Merryfield, William J. "Origin of Thermohaline Staircases." Journal of Physical Oceanography 30, no. 5 (May 2000): 1046–68. http://dx.doi.org/10.1175/1520-0485(2000)030<1046:oots>2.0.co;2.
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Begg, Paul. "Historic Timber Cantilever Staircases." Journal of Architectural Conservation 13, no. 1 (January 2007): 57–67. http://dx.doi.org/10.1080/13556207.2007.10784988.
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Simons, Stephen. "Minimax theorems with staircases." Archiv der Mathematik 57, no. 2 (August 1991): 169–79. http://dx.doi.org/10.1007/bf01190004.
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Zhang, Tianwei, Stéphane Caron, and Yoshihiko Nakamura. "Supervoxel Plane Segmentation and Multi-Contact Motion Generation for Humanoid Stair Climbing." International Journal of Humanoid Robotics 14, no. 01 (March 2017): 1650022. http://dx.doi.org/10.1142/s0219843616500225.
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Stair climbing is still a challenging task for humanoid robots, especially in unknown environments. In this paper, we address this problem from perception to execution. Our first contribution is a real-time plane-segment estimation method using Lidar data without prior models of the staircase. We then integrate this solution with humanoid motion planning. Our second contribution is a stair-climbing motion generator where estimated plane segments are used to compute footholds and stability polygons. We evaluate our method on various staircases. We also demonstrate the feasibility of the generated trajectories in a real-life experiment with the humanoid robot HRP-4.
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Ghaderi Garakani, Majid, Saeed Mahjoubi, and Shervin Maleki. "Effects of Modeling Staircases on Seismic Responses of Concrete Frames." Advanced Engineering Forum 23 (July 2017): 72–87. http://dx.doi.org/10.4028/www.scientific.net/aef.23.72.
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Staircases in reinforced concrete (RC) frame structures have suffered severe damages in past earthquakes, despite being regarded as the main means of egress during emergencies. To make sure that staircases perform as safe passages in strong earthquakes, the performance of RC stair structures should be scrutinized under major earthquakes. In this research at first, staircases were simulated as shell elements in RC frames and analyzed under gravity loads in order to find the maximum forces and moments. In the second step, the influence of staircases on the structural behavior of RC frame structures under seismic loads was studied. The results showed that stairs act as a K-type bracing system. Furthermore, a parametric study was carried out and relations for calculating force and moment in stairs slabs that had been determined under gravity loads, were modified. In addition, affected areas of structure interacting with the stairs in an earthquake were distinguished.