J.K. HAMPSHIRE, B.H.V. TOPPING and H.C. CHAN
This investigation assesses the bending performance of triangular plate elements with only three translational degrees of freedom per node in which the out‐of‐plane degree of…
Abstract
This investigation assesses the bending performance of triangular plate elements with only three translational degrees of freedom per node in which the out‐of‐plane degree of freedom is the only displacement considered. A review is presented of three element formulations followed by the results of a series of case studies which illustrate the element behaviour. Results obtained from elastic theory and finite element analysis using more complex element formulations are given for comparative purposes.
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A.S.L. Chan, T.A. Shankoff and D. Culver
Electrical leakage beyond control levels did not occur in high temperature and humidity stressing of surface insulation resistance patterns when the relatively high contamination…
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Electrical leakage beyond control levels did not occur in high temperature and humidity stressing of surface insulation resistance patterns when the relatively high contamination levels of 5 and 10 µg LiBr/cm were laminated into a simple test multilayer board structure. When sputtered layers of LiF, LiBr and NaCl were covered by a thin 0·002 in. lamination layer, generally similar results were obtained at 35°C/90% relative humidity and even at 85°C/85% relative humidity. Biasing of some samples at 85°C/85% relative humidity out to 400 hours did cause leakages which vary from one to three decades above the controls, but drifting with time beyond 96 hours towards a shorting condition, or to the level of unlaminated samples, on a leakage per square basis was not observed. Because the surface insulation resistance per square concept did not hold in these experiments, the surface leakage mechanism is apparently overridden by bulk leakages which occur in parallel in the laminations.
This paper describes the parent–child relationships of upper-middle-class Chinese parents and their adolescent children who were “parachuted” to the United States for private high…
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This paper describes the parent–child relationships of upper-middle-class Chinese parents and their adolescent children who were “parachuted” to the United States for private high schools. With parents remaining in China and children in the United States, thousands of miles away, such a transnational educational arrangement complicates the already volatile parent–child relationships during the adolescent years. Through ethnographic interviews of 41 students and 33 parents, I demonstrate different forms of child–parent relationships in a transnational education setting: those who found that the further physical and temporal distance has brought the parent–child relationship closer through frequent communications, children who experienced “accelerated growth” yet questioned the necessity, and delicate parent–child relationships due to increasing transnational cross-cultural or intergenerational differences. These types of parent–child relationships are not comprehensive of all the lived experiences of the “parachute generation,” yet they shed new light on transnational education and the unintended emotional dimensions of educational migration. In a transnational context for an economically well-off group, parental absence or separation of children and parents is no longer a clear-cut concept and has different layers of meanings, taking into account the frequency of communication, duration of spring and winter breaks and the existence of third-party agents such as for-profit intermediaries (or educational consultants) and host families. The diverse patterns of parent–child relations reveal the heterogeneity and complexities of “doing family” across geographic spaces and global educational hierarchies, as well as the roles of communication technologies, the tempo of mobilities and educational intermediaries.
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THE structural design of a long range ballistic missile or a space rocket vehicle is an intriguing problem. It is hardly necessary to stress the importance of achieving as light a…
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THE structural design of a long range ballistic missile or a space rocket vehicle is an intriguing problem. It is hardly necessary to stress the importance of achieving as light a structure as possible, since any unnecessary increase of structural weight can severely affect its performance or result in a profound increase of its total weight. There is a dearth of published information on this subject, presumably because of security restrictions. Among the papers available, only Sechler dwells on the structural design consideration in any detail. We have therefore very few specific facts to guide us, and can only relate the problem to our aircraft design experience with commonsense.
Ruchi Sinha, Louise Kyriaki, Zachariah R. Cross, Imogen E. Weigall and Alex Chatburn
This chapter introduces electroencephalography (EEG), a measure of neurophysiological activity, as a critical method for investigating individual and team decision-making and…
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This chapter introduces electroencephalography (EEG), a measure of neurophysiological activity, as a critical method for investigating individual and team decision-making and cognition. EEG is a useful tool for expanding the theoretical and research horizons in organizational cognitive neuroscience, with a lower financial cost and higher portability than other neuroimaging methods (e.g., functional magnetic resonance imaging). This chapter briefly reviews past work that has applied cognitive neuroscience methods to investigate cognitive processes and outcomes. The focus is on describing contemporary EEG measures that reflect individual cognition and compare them to complementary measures in the field of psychology and management. The authors discuss how neurobiological measures of cognition relate to and may predict both individual cognitive performance and team cognitive performance (decision-making). This chapter aims to assist scholars in the field of managerial and organizational cognition in understanding the complementarity between psychological and neurophysiological methods, and how they may be combined to develop new hypotheses in the intersection of these research fields.
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The in‐flight design problems of ballistic missile fuel tank structures are examined and simplified analyses are presented.
Xia Wang, Hong Ren, Weiguang Cai, Yan Liu and Lizi Luo
Green building (GB) has been actively promoted in many countries, but it has not become the mainstream in Chinese construction industry due to various reasons. This paper aims to…
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Green building (GB) has been actively promoted in many countries, but it has not become the mainstream in Chinese construction industry due to various reasons. This paper aims to investigate the major driving factors for the development of GB with reference of the Chinese construction market. Twenty-one factors influencing the development of GB were identified through a literature review, questionnaire survey, and face-to-face interview with professionals in the construction industry. Structural equation model was established to identify the critical driving path and three critical factors hierarchies. The result of model analysis also verifies the theoretical hypotheses that government body is the biggest motivation for the development of GB, and the path coefficient is high. The results demonstrate the necessity for the formulation of incentive policies and power of GB propaganda. We identify distinct government and market effects and then induce a government-led GB development path. These findings provide a valuable reference for government body aiming at promoting GB in the construction industry to put forward relevant policies and incentives and for the market body to understand the major driving factors and path when making decisions.
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Bellcore has two generic physical design criteria for telecommunications product cleanliness. Residual insoluble contamination levels are monitored by surface insulation testing…
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Bellcore has two generic physical design criteria for telecommunications product cleanliness. Residual insoluble contamination levels are monitored by surface insulation testing, and soluble ionic species by solvent extract conductivity testing. The previously undefined relationship between the two has been elucidated and is reported in this paper. Contamination of insulation resistance test pattern surfaces with LiBr at the criterion limit of 1 μg NaCl equivalent per cm2 results in surface insulation resistance levels in the 109 to 1010 ohm range, which is the criterion level. A discussion correlates the Bellcore cleanliness criteria with satisfactory performance of today's leakage sensitive ICs. Contamination levels at or above 5 μg NaCl equivalent per cm2 result in significant circuit corrosion and migration at 85°C/85% relative humidity stress, clearly indicating unsatisfactory field performance for a product with such contamination levels.
This study investigated the building energy, glare and daylight performance of overhang using building simulation software Energyplus in order to identify an optimal depth in hot…
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This study investigated the building energy, glare and daylight performance of overhang using building simulation software Energyplus in order to identify an optimal depth in hot summer and cold winter zone. A typical building with different window-to-wall ratios (WWR) was modeled and different overhang depths were considered. Results showed that the optimal overhang depths are 0.9m (WWR=0.15), 1.16m (WWR=0.3) and 1.62m (WWR=0.57), respectively. The total energy savings from overhang design can be ranging from about 3% to 24% depending on WWR and overhang depth. Moreover, the regression relationship between optimal overhang depth and WWR is given to help identify the best overhang dimension at the design stage. The potential energy saving performance for different WWRs then can be roughly inferred according to a total energy saving chart without building energy simulation. In conclusion, to be applicable in buildings, an overhang depth of 0.6-0.8m is suitable in this region since it has a balance in energy performance and aesthetic appearance.
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For reliable telecommunication systems, Bellcore recommends that Surface Insulation Resistance (SIR) be monitored at key points in printed wiring board and circuit pack…
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For reliable telecommunication systems, Bellcore recommends that Surface Insulation Resistance (SIR) be monitored at key points in printed wiring board and circuit pack manufacturing. The Bellcore SIR criteria are based on the old ‘Bell System’ test pattern having 0·025 inch conductor line widths, and 0·050 inch conductor spacings. Since divestiture, many equipment suppliers have suggested using different test patterns, or even conductors on actual product for SIR testing. Also, with the trend to high density packaging and smaller conductor spacings, the Bellcore pattern now represents old technology. This work confirms and advances prior work suggesting pattern translation based on the SIR per square concept. Essentially exact SIR per square correlation has been found over an order of magnitude of pattern conductor space widths. Critical experimental techniques to modify the FR‐4 epoxy surface appropriately and an important theoretical hypothesis involving shadowing (proven experimentally) are developed in this work.