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Understanding environmental perception is crucial for the autonomous navigation and motion planning of humanoid robots, especially in complex environments. Staircases pose a significant challenge as obstacles on them can disrupt planar features, leading to inaccurate parameter acquisition and potential missteps or falls. This study employs a methodology that integrates region growing and plane construction techniques. Initially, a depth camera captures the point clouds. Improved voxel filtering and straight pass filtering are applied to effectively eliminate noise, reduce data volume, and improve algorithm processing speed. The KD-Tree algorithm is then used to establish point cloud topology. By minimizing the sum of projections of neighboring points, the algorithm estimates normal vectors and accurately extracts staircase levels based on plane normal vector constraints. The region-growing clustering algorithm with adaptive parameters recognizes stair obstacles by defining cluster boundaries using statistical properties and principles. Individually clustered obstacles are then eliminated by assessing the region’s minimum points, whereas non-individually clustered obstacles are identified based on the maximum number of points in the region. Subsequently, the plane is constructed, and obstacles are eliminated by analyzing point mutations within the plane. In this study, obstacle elimination experiments were conducted using data from various obstacle-impaired staircases of inaccessible types. The data and experimental results were recorded and analyzed. Additionally, experiments were conducted to estimate staircase parameters with and without obstacle rejection. The elimination experiments demonstrate that the average correct rate for removing individually clustered obstacle point clouds is 92.13%, whereas non-individually clustered obstacles are removed with a 92.72% accuracy, leading to an overall elimination accuracy of 92.43%. These findings indicate the effectiveness of the proposed method in precisely identifying and eliminating various obstacles in staircase environments. In stair parameter estimation experiments, obstacles significantly hinder the humanoid robot’s ability to accurately measure step height and depth. The experimental results demonstrate that the maximum height error in stair parameter estimation when obstacles were present reached 30.55%, with the overall average relative error being 16%. However, once obstacles were removed, the errors in three-dimensional height measurements decreased to 8.53%, and the overall perception error dropped to approximately 7%. The average relative error in height is reduced to approximately 25% of that when obstacles are present, whereas the overall perception error decreases to about 50% of the error observed with obstacles. These findings highlight the profound impact obstacles have on stair perception and demonstrate that removing them substantially enhances the accuracy of stair parameter estimation.

Staircases, a part of architectural circulation and structure, can become a unique design value with the application technique that directs design and functionality. However, here, attention is drawn to the directive nature of the technique rather than its perception as a deterministic attitude in design. Bo Bardi’s architectonic approach has placed her in a distinguished position among modern architects. The effect of the architect’s staircase design and application technique on building tectonics is worth examining. Thus, this study aims to examine the staircases of Lina Bo Bardi, where design and technique are dissolved in integrity. Bo Bardi’s staircases were examined in terms of meaning, form, function, and technique, with classification for material use. In this context, unique situations were observed in the design and technical applications of reinforced concrete, wood, and metal materials used in stairs. The fact that the place, technique, and the architect’s thought guided the design turned the staircase into a symbolic value and has made the staircase the founding element of the space. This approach, which does not consider design and technique independently, creates a strong reference for today that structural elements such as stairs can be produced as symbols in space.

Copyright of Architecture & Life Journal / Kocaeli Üniversitesi Mimarlık ve Yaşam Dergisi is the property of Architecture & Life Journal / Kocaeli Universitesi Mimarllik ve Yasam Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Purpose: To be able to walk safely up or down a staircase, we must be able to judge the configuration and slope of the staircase and our viewing position. Adding markings to the stairs might help form correct perceptions of the staircase geometry. In this study, we examined how visual judgements about staircase configuration are affected by different marking patterns. Methods: Fifteen normally sighted young participants viewed computer‐generated images of staircases as seen from the top landing of the stairs. Marking patterns included contrasting baseboard, transverse edge‐stripes, longitudinal side‐stripes, longitudinal stripes, diamond patterns, longitudinal stripes extended to landing and diamond patterns extended to landing. For comparison, we included the no‐marking condition as a control. We tested several contrast levels of marking patterns (3.2%–50%), pitch lines of the staircases (shallow/medium/steep) and viewing positions (left/centre/right). The effect of the overall shape cue of the staircase on participants' performance was also evaluated. We measured participants' accuracies in judging whether the staircase was shallow, medium or steep, and whether the viewing position was located to the left, centre or right. Results: Transverse edge‐stripes markings yielded fewer underestimations of slope (9% [transverse] vs. 18% [others]) when compared with other markers. The presence of an overall shape cue helped both slope (67% [presence] vs. 51% [absence]) and viewing position judgements (79% [presence] vs. 62% [absence]). When the overall shape cue was present, only the transverse edge‐stripes markings yielded a significant improvement in performance (compared with no‐marking condition). When the cue was absent, performance was significantly better with markings with high and moderate contrasts. Conclusions: Adding marking patterns such as high‐contrast transverse stripes to stairs may help enhance the visibility of the stairs and judgements of staircase geometry. This might be particularly useful for people with visual impairment or normally sighted individuals under compromised environmental conditions. [ABSTRACT FROM AUTHOR]

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.

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. [ABSTRACT FROM AUTHOR]

Modern gas turbines have evolved by increasing the turbine inlet temperature (TIT) to improve performance. This development has led to a demand for cooling techniques. Among these, the film cooling, which involves injecting compressed air through holes on the turbine surface, is a prominent cooling technique used to protect the turbine surface. In this study, a comparative analysis is conducted between the conventional fan-shaped film cooling hole, primarily used in film cooling techniques, and modified shapes achieved by altering the geometry of the film cooling hole based on a fan-shaped hole to assess and compare the cooling performance on a flat plate surface. The adiabatic film cooling effectiveness was measured for three film cooling holes, the Baseline of a 7-7-7 fan-shaped film cooling hole, namely, Staircase, which had a double-step at the hole exit, and Compound Expansion, which had an additional expanded flow path at the hole leading edge. The used measurement technique was the pressure-sensitive paint (PSP) technique, using nitrogen gas as the foreign gas, and experiments were conducted at a density ratio of 1.0 and blowing ratios ranging from 0.5 to 2.0. The results reveal that the modified holes featured wider lateral expansion at the hole exits, resulting in a broader distribution of the cooling effectiveness in the lateral direction compared to the Baseline. The Staircase shows a better performance, although an overall cooling effectiveness trend similar to that of the Baseline. Furthermore, the Compound Expansion demonstrates an enhancement in the cooling performance with an increased blowing ratio, notably achieving nearly double the cooling effectiveness compared to that of the Baseline at a blowing ratio of 2.0. [ABSTRACT FROM AUTHOR]

Several studies have previously been conducted to improve the cooling performance of film cooling. However, most of the research has conducted experiments with film cooling holes on flat plates, and thus, the results of these studies do not encompass the influence of the complex mainstream behavior within the turbine passage on film cooling. In this study, three different film cooling hole configurations were installed on the endwall of a turbine linear cascade to measure adiabatic film cooling effectiveness and evaluate cooling performance. The film cooling holes compared in the experiment for film cooling effectiveness were a 7-7-7 fan-shaped hole (Baseline), a Baseline with a double-step structure at the hole exit (Staircase), and a Baseline with an additional expanded passage at the hole leading edge (Compound Expansion). A total of nine holes were manufactured on the turbine endwall to assess film cooling performance, as various factors, such as mainstream acceleration, secondary flow within the turbine passage, and so on, can influence film cooling. Adiabatic film cooling effectiveness was measured using the pressure-sensitive paint (PSP) technique. Mass flow ratios ranging from 0.25% to 1.25% of the mass flow rate of a single turbine passage were supplied to the plenum chamber within the test rig. As a result, all experimental results confirmed the impact of secondary flow within the turbine passage on film cooling. In the case of the Staircase, it exhibits an overall cooling trend similar to the Baseline. It shows small cooling performance degradation compared with Baseline due to lift-off, and its double-step structure laterally expanding results in better cooling performance at high mass flow ratio (MFR) conditions. For the Compound Expansion, at low MFR, the momentum of the coolant is lower compared with other configurations, leading to lower cooling performance due to the influence of secondary flow. However, at high MFR, the Compound Expansion provides wider protection compared with other hole geometries and shows high cooling performance. [ABSTRACT FROM AUTHOR]

One of the most precise methods to establish psychometric functions and estimate threshold and slope parameters is the constant stimuli procedure. The large distribution of predetermined stimulus values presented to observers enables the psychometric functions to be fully developed, but makes this procedure time-consuming. Adaptive procedures enable reliable threshold estimation while reducing the number of trials by concentrating stimulus presentations around observers' supposed threshold. Here, the stimulus value for the next trial depends on observer's responses to the previous trials. One recent improvement of these procedures is to also estimate the slope (related to discrimination sensitivity). The Bayesian QUEST+ procedure (Watson Journal of Vision, 17(3), 10, 2017), a generalization and extension of the QUEST procedure, includes this refinement. Surprisingly, this procedure is barely used. Our goal was to empirically assess its precision to evaluate size, orientation, or temporal perception, in three yes/no discrimination tasks that increase in demands. In 72 adult participants in total, we compared points of subjective equivalence (PSEs) or simultaneity (PSSs) as well as discrimination sensitivity obtained with the QUEST+, constant stimuli, and simple up-down staircase procedures. While PSEs did not differ between procedures, sensitivity estimates obtained with the 64-trials QUEST+ procedure were overestimated (i.e., just-noticeable differences, or JNDs, were underestimated). Overall, agreement between procedures was good, and was at its best for the easiest tasks. This study empirically confirmed that the QUEST+ procedure can be considered as a method of choice to accelerate PSE estimation, while keeping in mind that sensitivity estimation should be handled with caution. [ABSTRACT FROM AUTHOR]

This study aims to reduce the time and effort required to design an economical spiral staircase according to the latest ACI code. Geometrically, the spiral staircase is a complex 3D structure subjected to three forces and three moments. The values of the six internal stresses generated in each section vary along the staircase and are calculated through a series of long and complex equations. By creating six simplified diagrams of all the variable forces and moments, two locally familiar cases were designed: one with a total angle of 240° and other with an angle of 180°. The created diagrams represent the easiest way to find the locations of the maximum forces and moments. Thus, the structural analysis results will be ready for the design according to approved specifications. After creating algorithms based on ACI-19 requirements, the authors designed both cases and drew the details of the reinforcing bars. In comparison, it is considered more appropriate to construct stairs of 180° in residential and commercial buildings because they meet the architectural requirements and are more economical than those of 240°. [ABSTRACT FROM AUTHOR]

The staircase method has been widely used in measuring perceptual learning. Recently, Zhao, Lesmes, and Lu (2017, 2019) developed the quick Change Detection (qCD) method and applied it to measure the trial-by-trial time course of dark adaptation. In the current study, we conducted two simulations to evaluate the performance of the 3-down/1-up staircase and qCD methods in measuring perceptual learning in a two-alternative forced-choice task. In Study 1, three observers with different time constants (40, 80, and 160 trials) of an exponential learning curve were simulated. Each simulated observer completed staircases with six step sizes (1%, 5%, 10%, 20%, 30%, and 60%) and a qCD procedure, each starting at five levels (+50%, +25%, 0, -25%, and -50% different from the true threshold in the first trial). We found the following results: Staircases with 1% and 5% step sizes failed to generate more than five reversals half of the time; and the bias and standard deviations of thresholds estimated from the post hoc segment-by-segment qCD analysis were much smaller than those from the staircase method with the other four step sizes. In Study 2, we simulated thresholds in the transfer phases with the same time constants and 50% transfer for each observer in Study 1. We found that the estimated transfer indexes from qCD showed smaller biases and standard deviations than those from the staircase method. In addition, rescoring the simulated data from the staircase method using the Bayesian estimation component of the qCD method resulted in much-improved estimates. We conclude that the qCD method characterizes the time course of perceptual learning and transfer more accurately, precisely, and efficiently than the staircase method, even with the optimal 10% step size.

The learning curve in perceptual learning is typically sampled in blocks of trials, which could result in imprecise and possibly biased estimates, especially when learning is rapid. Recently, Zhao, Lesmes, and Lu (2017, 2019) developed a Bayesian adaptive quick Change Detection (qCD) method to accurately, precisely, and efficiently assess the time course of perceptual sensitivity change. In this study, we implemented and tested the qCD method in assessing the learning curve in a four-alternative forced-choice global motion direction identification task in both simulations and a psychophysical experiment. The stimulus intensity in each trial was determined by the qCD, staircase or random stimulus selection (RSS) methods. Simulations showed that the accuracy (bias) and precision (standard deviation or confidence bounds) of the estimated learning curves from the qCD were much better than those obtained by the staircase and RSS method; this is true for both trial-by-trial and post hoc segment-by-segment qCD analyses. In the psychophysical experiment, the average half widths of the 68.2% credible interval of the estimated thresholds from the trial-by-trial and post hoc segment-by-segment qCD analyses were both quite small. Additionally, the overall estimates from the qCD and staircase methods matched extremely well in this task where the behavioral rate of learning is relatively slow. Our results suggest that the qCD method can precisely and accurately assess the trial-by-trial time course of perceptual learning.

Staircase adalah jenis saklar yang memiliki fitur waktu tunda dan dipakai pada praktikum Perancangan Listrik 1 dan Instalasi Listrik 2. Jumlah saklar Staircase yang dimiliki sedikit dan frekuensi pemakaiannya yang tinggi menyebabkan saklar tersebut cepat rusak serta harga saklar Staircase tergolong cukup mahal menjadi penyebab saklar ini belum memadai dilihat dari segi jumlah dan penggunaanya. Staircase dan Relay Timer adalah objek utama pada penelitian ini, dimana riset diawali dengan identifikasi masalah pada saklar Staircase, selanjutnya menganalisa jenis komponen yang dibutuhkan sebagai pengganti saklar Staircase tanpa mengurangi fitur dan kemampuan sebelumnya kemudian mendesain rangkaian Relay Timer yang dapat dioperasikan pada sistem 3 dan 4 kawat. Pengujian terhadap modul Relay Timer dilakukan untuk mengetahui kemampuan dan keandalannya dan juga untuk memastikan prinsip kerja modul Relay Timer telah sesuai dengan Staircase, selain itu pengujian dilakukan untuk mengetahui fitur dan kelebihan dari modul Relay Timer sebelum digunakan pada praktikum kuliah. Berdasarkan pengujian, pengaturan waktu pada modul Relay Timer sesuai dengan hasil pengukuran waktu menggunakan stop watch, baik sistem 3 kawat dan 4 kawat artinya pengaturan waktu pada modul Relay Timer telah sesuai seperti yang diharapkan bahkan lebih akurat dibandingkan dengan Staircase. Terdapat fitur tampilan/ display digital pada modul Relay Timer yang tidak dimiliki Staircase.

In many ways, the reliability of vertical cylindrical tanks is determined by the resistance to buckling of the wall. In the current work, a variant of a detailed design scheme is considered, taking into account the presence of a spiral technological staircase for servicing the tank roof. The possibility of using the specified structural element as an external reinforcement to increase stability is analyzed. Finite element models of tanks with volumes of 10..30 thousand m3 were developed. The models took into account the actual distribution of the wind flow for tanks with a circular staircase. Using a multifactorial experiment, an analysis of the stability and stress state of the tank wall was carried out. The variable parameters were: the design solution of the stairs, the dimensions of the tanks and the load. Corresponding graphs and diagrams were constructed. As a result, the design solution and the recommended angle of inclination of the spiral staircase in the range of 30–40° were substantiated. The application of the obtained solutions improved the stability in the annular direction by up to 13 % compared to standard solutions. Wall displacements from wind load are reduced by 14 %, in turn, local stresses in the ladder attachment areas increased by no more than 5 %. In general, the inclusion of spiral staircases significantly increases the stability of the tank wall and can be considered as a good alternative to standard reinforcement methods.

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. [ABSTRACT FROM AUTHOR]

A rubber isolation bearing installed in a staircase (RBS) was proposed to mitigate seismic damages to the component of staircases and improve their seismic performance. A series of quasi-static tests performed with respect to the horizontal and vertical mechanical properties of RBS as well as the numerical modelling were verified with experimental results. Next, the finite element models of typical types of reinforced concrete frames (without stairs, with cast-in-place reinforced concrete stairs, and with RBS stairs) were established. The modal dynamic and non-linear elasto-plastic analyses of system-level building models were herein conducted, respectively. The effect of the RBS on the dynamic response of the whole structure and the mechanical performance of stair components was revealed. The analysis results indicated that the RBS provided the desired floor-to-floor relative drift and effectively isolate the seismic action from the stair flight. Therefore, the presence of RBS can effectively mitigate the influence of a staircase on the entire building's structure, weaken the diagonal strut effect of flights, and reduce the inner forces of staircase components. [ABSTRACT FROM AUTHOR]

Staircase testing is a standard method for evaluating the fatigue strength of components. However, staircase testing assumes a normal distribution, while components can display bimodal behavior due to flaws in material, or issues during the manufacturing process. Three unique step loading data sets on different production crankshafts provide evidence that step loading reliably identifies material or manufacturing issues, which lower a component's fatigue strength. Staircase testing has an 87% or greater chance of overestimating the component's fatigue strength, which in turn overestimates the component's expected reliability. For example, a component with a 99.9% reliability based on staircase testing would only have a 74% reliability based on step loading. If a component contains an undetectable manufacturing defect, staircase testing has a 99% chance of overestimating the component's fatigue strength. Step loading reliably improves the estimation of a component's fatigue strength distribution while providing insights into a component's defect tolerance. Highlights: Staircase testing overestimates a component's fatigue strength.Step loading reliably identifies issues that lower a component's fatigue strength.Step loading improves estimation of a component's fatigue strength distribution. [ABSTRACT FROM AUTHOR]

Among the most characteristic elements of the Béjar Ducal Palace courtyard is the magnificent staircase made up of a large linteled arch that rests on Ionic columns with skewed capitals following the slope of the lintel. One of the capitals shows a different shape as it is bent. It consists of two halves, one of them in the common shape and the other one in a skewed shape. We deduce that there was a first project of the staircase that had to be modified. Master stonemason Pedro de Marquina's (author of the first conditions of the Project) knowledge of stone stereotomy suggests he was; the project architect, the execution director and the architect that modified the project during the work. [ABSTRACT FROM AUTHOR]

The aim was to investigate the vertical root fracture (VRF) resistance and crack formation of root canal-treated teeth restored with different post-luting systems. Human maxillary lateral incisors of similar size were decoronated, assigned to five groups (n = 18, power = 0.9) and embedded in acrylic blocks with artificial periodontal ligament. After root canal filling, post spaces were prepared to place coated fiber-reinforced composite (FRC) or sandblasted titanium (Ti) posts of the same shape and size. Half of the posts were zinc phosphate cemented (C), while the other half was adhesively luted (A). Untreated teeth served as control. After thermal cycling and staircase loading in a chewing simulator, the crack formation on the root dentin surface was microscopically examined and classified as no defect, craze line, vertical crack, and horizontal crack. Subsequently, the samples were loaded until root fracture. Data were analyzed by one-way ANOVA, Tukey's test, and Fisher's exact test. All samples survived the chewing simulation without VRF, but crack formation was significantly different between the groups (P = 0.009). The control showed significantly fewer defects than FRC/C, Ti/C, and Ti/A (P = 0.001, P = 0.008, P = 0.008, respectively). FRC/C showed the highest incidence of vertical cracks. FRC/A had the lowest incidence of defects. There was no significant difference in VRF resistance between the groups (P = 0.265). Adhesively luted FRC posts did not increase VRF resistance but reduced the risk of defects. Most defects were craze lines and vertical root cracks. [ABSTRACT FROM AUTHOR]

In engineering applications, fatigue phenomenon is a key issue and needs to be analyzed in the beginning of design phase in case of any component exposed to alternating loading on operation otherwise catastrophic fatigue failure may cause. Component can be designed with safe-life, fail-safe, and damage tolerant approach based on whether redundant load path and damage sensitive. Before starting analyzing the structure, material allowable data needs to be presented in a reliable way to predict fatigue life of components. SN curves with presented confidence levels are the robust approach to make a prediction on safe life of a structure in terms of fatigue. In this point, there are so many approaches to determine fatigue limit of materials and issue shall be handled by statistical manner. In literature, different staircase and curve fitting methods were presented to estimate endurance limit of materials and some reliability manuscript published. In this paper, fatigue limit of AISI 4340 steel will be investigated through most convinced staircase and curve fitting approaches and their reliability will be queried

Electric bicycle (E-bike) fires have attracted more concerns recently in the field of fire safety science since several fatal fires occurred especially in residential buildings. This paper conducts a full-scale experiment of E-bike fire in a typical high-rise residential building of China. Fire and smoke characteristics as well as their influences on the residents’ safety and evacuation are studied. It was found that E-bike fire grows quite rapidly once ignited. Less smoke could spread into these residential rooms with closed door. Sealing the entrance door gap could effectively help to prevent the smoke. At the very first stage of the fire (around 4.5min from igniting), the residents could choose to evacuate downstairs. However, it is a better option to stay at home waiting for help during most of the fire period. Smoke from this fire did not exceed the height of the 10th floor in the staircase. Thus, for the residents on the 10th floor and above, to escape through the staircase upward to the building roof is another safe option. Fire Dynamics Simulator (FDS) was used to numerically reconstruct this fire. The numerical results show good agreement with the experiments. Based on accurate parameters and boundary conditions, FDS is verified to be feasible to conduct numerical reconstruction of E-bike fires for the purpose of assisting fire investigation.

In this work, we conducted downward evacuation experiments in four types of staircases under various smoke visibility conditions of the naked eye, wearing sunglass and wearing eyeshades. Ten male and ten female college students were recruited to conduct the evacuation as a single male, single female, two males supporting one another, two females supporting one another and one male carrying another on his back. The evacuation time on each floor was recorded. The corresponding evacuation models were established by Pathfinder and verified against the test data. The effects of evacuation crowd density and response time considering gender factors on the evacuation time were simulated using the models. The results show that under the experimental condition of low visibility, the curve of evacuation time presents a stable state, whose change with the increase in the floors is not obvious. The increase in the evacuation time under different visibility indicates that males have better adaptability to the environment than females. The curves of SSP (straight running stairs with platform) and DSS (double split parallel stairs) are smoother than those of DPS (double running parallel stairs) and CS (corner stairs), indicating less pressure and less congestion during evacuation. During the emergency evacuation, the crowd pressure on the platform of the staircases is small. The front section of the flight and the corner part of the staircases are prone to congestion during evacuation. Under the influence of gender factors, since the response time of males is longer than that of females, the smaller the proportion of males, the smaller the time growth rate considering the reaction time. With the increase in crowd density, the effect of response time on total evacuation time becomes smaller. [ABSTRACT FROM AUTHOR]

In this communication, a low-profile circularly polarized (CP) staircase curl antenna array with 2:1 impedance bandwidth and 50% axial ratio (AR) bandwidth is proposed for fifth-generation (5G) millimeter-wave (mmW) communications. It overcomes a vital drawback of complex multilayer structure of the wideband CP antenna array. By fully taking advantage of 3-D staircase layout, the curl element achieves 2:1 impedance bandwidth, 57.9% AR bandwidth, and a maximum gain of 7.4 dBic. Accordingly, benefiting from the tapered matching transformer, a single-layer full-corporate microstrip feeding network with 111.4% impedance bandwidth is constructed. For demonstration, an $8\times8$ staircase curl antenna array is designed on three-layer PCB laminates. The proposed antenna array is measured with an impedance bandwidth of 76.9% (20.0–45.0 GHz) and an AR bandwidth of 53.6% (23.1–40.0 GHz), demonstrating a promising candidate to be used in 5G mmW communications. [ABSTRACT FROM AUTHOR]

One of the components of the Haadi Plan is the development of rural passage networks. The network of passages is considered as the main mmaters of the village because all human, livestock and commodity transport is possible in these communication networks. The network paths do not follow a specific pattern and are a function of the terrain variables (roughness, height, and slope). The purpose of this study was to assess the compliance of the standards of road adjustment with the needs of the villagers in the mountainous areas of Paveh using descriptive-analytical and field research. Nine mountainous villages were randomly selected in Paveh and 83 pedestrian networks were examined for slope percentage, path forms, and elevation levels. Local people's views were sought on physical dimensions of the passages using 16 questions. Mean and chi-square analysis were used for data analysis. The findings related to elevation indicated that the villages were 1250 to 1750 m above sea level. In terms of slope, 24 passageways had slopes above 40%; 32 passageways had slopes between 20-39% and 19 passageways were less than 20% in slope and were open and roofed in texture. The results showed that 66% of the respondents identified the road network renovation to be in accordance with the needs of the village. Therefore, the findings point to the need to improve the rural passage network. Al rural passages should be covered by the executive. Second, the use of quality materials ensures the viability of the passage network. Third, the height factor should be taken into account in making it easier to climb the stairs.

Using the example of the great staircase, one of the most important ceremonial rooms in palatial buildings in the early modern period, this article aims to investigate clients’ attitudes in relation to France and Italy in the Holy Roman Empire during the first half of the 18th century. This was partly a political phenomenon but it was also linked to travel and the theoretical treatises that may have contributed to the formation of Germanic architectural culture through the prism of these two countries. Some significant cases are analysed from manuscript and printed sources, and in particular the key role of the texts of Leonhard Christoph Sturm. Between 1700 and 1750, reference to France and Italy declined in the Empire.

The external wind can change smoke movement patterns inside the staircase and affect smoke exhaust efficiency. This paper analyzes the smoke back-layering phenomenon in the staircase with open stair doors below the fire floor. The effect of the open stair door location and the heat release rate of fires and external wind velocities on smoke movement patterns are investigated numerically. The external wind ranges from 0–5.5 m/s. At 0 m/s, the smoke back-layering phenomenon driven by pressure difference can be found in the staircase with all stair doors closed. With the increasing wind velocity, four smoke behaviors are identified: upward moving smoke, first downward then upward moving smoke, downward moving smoke, and no smoke. Results show that the back-layering distance is mainly influenced by the external wind and heat release rate of fires. Correlations are modified and used to predict the longest back-layering distance with the first downward then upward moving smoke. This helps with arranging the smoke detectors inside a staircase and the fire safety design of high-rise buildings. [ABSTRACT FROM AUTHOR]

Laboratory-based fatigue test methods are often used to estimate the life of components in service conditions. Two common laboratory-based methods used for fatigue durability are the Staircase and the Over-Stress Probe (OSP) methods. Both methods are widely used in academia and industry; both have benefits and limitations in adequately providing for a lifespan estimation. A study was conducted to examine the results from staircase and OSP fatigue tests on 176 specimens taken from AlSiCuMg engine block castings. The OSP method was found to allow a more complete fractographic assessment of porosity compared to the staircase method. It is concluded that the OSP method yields information to better drive decisions regarding process changes that influence desired specific outcomes in terms of product performance and durability. [ABSTRACT FROM AUTHOR]

This article analyses the 'stair culture' of Hong Kong Island, a place that is constrained by its topography, economic, and social-historical conditions. Staircases are interwoven into an infrastructure of vertical and horizontal pathways. Instead of just being a means of access, staircases play a key role in shaping the urban island. Through a critical examination of these structures and relevant literary and filmic texts (Leung Ping-Kwan's poems, Wong Kar-wai's films, and Tsai Ming-liang's Walker series [2012]), the article provides a way of understanding the extent to which the perception of Hong Kong Island is re-imagined by way of an urbanscape punctuated by staircases. Staircases have the ability to mix up people in different classes in such places as the Central to Mid-Levels area and Sai Ying Pun Centre Street. Both districts are initially connected by staircases and later escalators. By examining the impact of escalators (such as high-speed gentrification, closing down of local stores, and the loss of real public spaces) and the effects of staircases on cultural activities in different areas, this article argues that staircases expose the nature of a classed society in Hong Kong Island - and, by extension, Hong Kong as a whole - and represent a nostalgia that is potentially productive. [ABSTRACT FROM AUTHOR]

Fire is one of the most common risks to the environment and human health. Fire, depending on the conditions of combustion and the type of fuel, can emit many toxic products. The paper presents numerical analyzes of the conditions that can occur in a building during a fire. The conditions were analyzed in terms of the safety of the occupants and possible emissions of pollutants into the atmosphere. The temperature, propagation of smoke, and emission of pollutants were analyzed. A numerical model was created using Fire Dynamics Simulator (FDS) software. The model represents a staircase and a corridor in a real building located at the Silesian University of Technology in Poland. The results show that safe conditions are only ensured for a limited time, and emissions can also be harmful to occupants and the environment. [ABSTRACT FROM AUTHOR]

To quantitatively assess the risks of pedestrian evacuation through staircases with different slopes when a flood intrudes into the underground space, a numerical model was designed to simulate flood flow patterns on staircase and escalator under different slope conditions (26.6°, 28.2°, 29.1°, 30°, and 35°). A safety index (F (v2, y)) was employed to assess the risks of pedestrian evacuation through the staircase under different slopes. When the water depth at the staircase entrance (under slopes ranging from 26.6° to 28.2°) was 0.3 m and the unit width discharge was 0.28 m2/s, pedestrians safely evacuated the underground space. However, when the staircase slope was beyond 28.2°, the safety index value was higher than the critical value and the flood caused serious threats to them. Therefore, it is suggested that when the underground space becomes flooded, pedestrians should avoid steep slopes and choose a gentle staircase as a safer escape route. The obtained results provide a theoretical guideline for pedestrian evacuation from a flooded staircase. [ABSTRACT FROM AUTHOR]

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.

A rubber isolation bearing installed in a staircase (RBS) was proposed to mitigate seismic damages to the component of staircases and improve their seismic performance. A series of quasi-static tests performed with respect to the horizontal and vertical mechanical properties of RBS as well as the numerical modelling were verified with experimental results. Next, the finite element models of typical types of reinforced concrete frames (without stairs, with cast-in-place reinforced concrete stairs, and with RBS stairs) were established. The modal dynamic and non-linear elasto-plastic analyses of system-level building models were herein conducted, respectively. The effect of the RBS on the dynamic response of the whole structure and the mechanical performance of stair components was revealed. The analysis results indicated that the RBS provided the desired floor-to-floor relative drift and effectively isolate the seismic action from the stair flight. Therefore, the presence of RBS can effectively mitigate the influence of a staircase on the entire building’s structure, weaken the diagonal strut effect of flights, and reduce the inner forces of staircase components.

Slabless reinforced concrete (RC) staircases attract architects with their aesthetically pleasing appearance and are therefore especially preferred for the interior design of prestigious buildings. The design and detailing of such staircases are based on analytical approaches and engineering judgment. However, these analytical methods are not supported by extensive experimental research. Besides, engineers have to deal with lots of uncertainties due to a lack of experimental data. Therefore, experimental research was conducted to investigate the flexural behavior of slabless staircases. A total of 12 two-thirds-scaled specimens with four different reinforcement arrangements and three different tread/riser thicknesses were prepared for testing under six-point monotonic loading. The results show that tread thickness, rather than riser thickness, significantly affects the behavior of slabless staircases. In addition, it has been found that the planar reinforcement can greatly improve the behavior and prevent possible bonding problems. The results are also consistent with the adopted analytical approaches. [ABSTRACT FROM AUTHOR]

In engineering applications, fatigue phenomenon is a key issue and needs to be analyzed in the beginning of design phase in case of any component exposed to alternating loading on operation otherwise catastrophic fatigue failure may cause. Component can be designed with safelife, fail-safe, and damage tolerant approach based on whether redundant load path and damage sensitive. Before starting analyzing the structure, material allowable data needs to be presented in a reliable way to predict fatigue life of components. SN curves with presented confidence levels are the robust approach to make a prediction on safe life of a structure in terms of fatigue. In this point, there are so many approaches to determine fatigue limit of materials and issue shall be handled by statistical manner. In literature, different staircase and curve fitting methods were presented to estimate endurance limit of materials and some reliability manuscript published. In this paper, fatigue limit of AISI 4340 steel will be investigated through most convinced staircase and curve fitting approaches and their reliability will be queried. [ABSTRACT FROM AUTHOR]

Many countries have implemented regulations or guidance concerning the use of elevators solely for people with mobility limitations for evacuation during fires. However, there is uncertainty regarding whether people without disabilities may want to use the elevators during an emergency, which could lead to inoperability of the elevators or crowd accidents. This research conceptualized a nudge solution that can reduce the undesirable motivation of people without disabilities to try to use elevators solely for people with mobility limitations. The solution is based on an ordinary phased-evacuation strategy and was assessed experimentally. Twenty-five participants who were fire safety professionals were gathered in a 47th-floor meeting room of a 50-story building. They were instructed to evacuate to the nearest staircase/elevator lobby where a wheelchair user was waiting for rescue by elevator. The participants were immersed in four virtual cases that replicated the evacuation behavior of other people without disabilities in the actual lobby. The results showed that reducing the queuing and wait time in the lobby by phased evacuation can reduce the motivation of people without disabilities to use the elevator. An ordinary phased-evacuation for crowd management can also contribute to safe elevator use by people with mobility limitations. • Crowd management for safe elevator use by wheelchair users is presented. • Evacuees are nudged; if they can enter a staircase smoothly, they choose to do so. • This approach will not need an objective definition of who should use the elevator. • Phased evacuation can also contribute to safe evacuation of wheelchair users. • The virtual experiment takes place within an actual high-rise building. [ABSTRACT FROM AUTHOR]

3D NAND is a great architectural innovation in the field of flash memory. The staircase for control gate is a unique and important process in the manufacturing of 3D NAND. The staircase is employed to form the electrical connection between the control gate and contact. The current method used to measure the dimension of staircase patterns is, however, not precise enough for the development of state-of-the-art 3D NAND. In this circumstance, an accurate measurement of dimension for as-formed staircase patterns is of great importance and technical interest. In this paper, an improved measurement method is proposed to meet the requirement for higher precision. By taking the overlay into account, a calculation formula for measuring the dimensional error of as-formed staircase is derived for the first time. Two kinds of anchor design (convex SS0 and concave SS0) are put forward to perform dedicated experiments. Achieved results show that the measurement error of as-formed staircase using this improved method is improved from 31.6 nm for normal measurement method to 14.1 nm. The dimensional uniformity of as-formed staircase is therefore improved significantly which in turn leads to well controlled word line leakage. Furthermore, in advanced staircase structure of stair divided scheme (SDS), the convex SS0 shows an advantage in cost compared to the concave SS0.

Summary: A method to collect the times and travel routes in predefined sections of stairs is presented, in order to obtain walking velocities of children. Twenty‐seven possible travel paths on landings and nine possible travel paths on flights are proposed and the equations developed to calculate them are presented. Experiments were carried out where data were not collected from fire drills, as usually are, but from the movement of unimpeded individuals descending stairs using this method. The technique used to collect data was the observation of video recordings via a closed‐circuit television system. Seven hundred and eighty‐three students ranging from 6 to 10 years of age and from three different schools participated in the experiments. Particularly, movements on stair flights and landings were analyzed separately for a group of 54 students of the first grade (6 years‐old), for a comparative analysis of the distances and velocities obtained with methods used by other researchers and significant differences were found. In addition, by the present method, the dispersion of velocity values in a population was studied; thus, the shape of its frequency distribution could be verified. An uncertainty estimative of the method is presented together with the discussion of its usage difficulties. [ABSTRACT FROM AUTHOR]

This paper aims to analyze the façade and staircase of the historic building of the University of Salamanca as an expression of the relationship between philosophy, theology and art in the Spanish Siglo de Oro, and will try to provide a new perspective on the sculptural elements present in both spaces of the university. There are few interpretations on this subject, but they all converge on understanding sculptures as an expression of the myth of the Spanish monarchy. This essay, instead, will show how those same elements can be read in relation to the moral and anthropological needs of 16th century humanity and, thus, that the relationship between university spaces and the people who frequent them is even closer. To enter a space, according to such an interpretation, does not simply mean to use it, but to frequent it and understand in it and from it reflections for everyday life.

In this work, we conducted downward evacuation experiments in four types of staircases under various smoke visibility conditions of the naked eye, wearing sunglass and wearing eyeshades. Ten male and ten female college students were recruited to conduct the evacuation as a single male, single female, two males supporting one another, two females supporting one another and one male carrying another on his back. The evacuation time on each floor was recorded. The corresponding evacuation models were established by Pathfinder and verified against the test data. The effects of evacuation crowd density and response time considering gender factors on the evacuation time were simulated using the models. The results show that under the experimental condition of low visibility, the curve of evacuation time presents a stable state, whose change with the increase in the floors is not obvious. The increase in the evacuation time under different visibility indicates that males have better adaptability to the environment than females. The curves of SSP (straight running stairs with platform) and DSS (double split parallel stairs) are smoother than those of DPS (double running parallel stairs) and CS (corner stairs), indicating less pressure and less congestion during evacuation. During the emergency evacuation, the crowd pressure on the platform of the staircases is small. The front section of the flight and the corner part of the staircases are prone to congestion during evacuation. Under the influence of gender factors, since the response time of males is longer than that of females, the smaller the proportion of males, the smaller the time growth rate considering the reaction time. With the increase in crowd density, the effect of response time on total evacuation time becomes smaller.