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Building Systems (building + system)
Selected AbstractsEffects of granularity of search results on the relevance judgment behavior of engineers: Building systems for retrieval and understanding of contextJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 3 2010Panos Balatsoukas Granularity is a novel concept for presenting information in search result interfaces of hierarchical query-driven information retrieval systems in a manner that can support understanding and exploration of the context of the retrieved information (e.g., by highlighting its position in the granular hierarchy and exposing its relationship with relatives in the hierarchy). Little research, however, has been conducted on the effects of granularity of search results on the relevance judgment behavior of engineers. Engineers are highly motivated information users who are particularly interested in understanding the context of the retrieved information. Therefore, it is hypothesized that the design of systems with careful regard for granularity would improve engineers' relevance judgment behavior. To test this hypothesis, a prototype system was developed and evaluated in terms of the time needed for users to find relevant information, the accuracy of their relevance judgment, and their subjective satisfaction. To evaluate the prototype, a user study was conducted where participants were asked to complete tasks, complete a satisfaction questionnaire, and be interviewed. The findings showed that participants performed better and were more satisfied when the prototype system presented only relevant information in context. Although this study presents some novel findings about the effects of granularity and context on user relevance judgment behavior, the results should be interpreted with caution. For example, participants in this research were recruited by convenience and performed a set of simulated tasks as opposed to real ones. However, suggestions for further research are presented. [source] Investigation of the sliding behavior between steel and mortar for seismic applications in structuresEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 12 2009Jason McCormick Abstract The friction developed between a steel base plate and a mortar base contributes shear resistance to the building system during a seismic event. In order to investigate the possible sliding behavior between the base plate and the mortar, a shake table study is undertaken using a large rigid mass supported by steel contact elements which rest on mortar surfaces connected to the shake table. Horizontal input accelerations are considered at various magnitudes and frequencies. The results provide a constant friction coefficient during sliding with an average value of approximately 0.78. A theoretical formulation of the friction behavior is also undertaken. The theoretical equations show that the sliding behavior is dependent on the ratio of the friction force to the input force. The addition of vertical accelerations to the system further complicates the sliding behavior as a result of the varying normal force. This results in a variable friction resistance which is a function of the amplitude, phase, and frequency of the horizontal and vertical input motions. In general, this study showed a consistent and reliable sliding behavior between steel and mortar. Copyright © 2009 John Wiley & Sons, Ltd. [source] Hybrid platform for high-tech equipment protection against earthquake and microvibrationEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2006Y. L. Xu Abstract To ensure the high quality of ultra-precision products such as semiconductors and optical microscopes, high-tech equipment used to make these products requires a normal working environment with extremely limited vibration. Some of high-tech industry centres are also located in seismic zones: the safety of high-tech equipment during an earthquake event becomes a critical issue. It is thus imperative to find an effective way to ensure the functionality of high-tech equipment against microvibration and to protect high-tech equipment from damage when earthquake events occur. This paper explores the possibility of using a hybrid platform to mitigate two types of vibration. The hybrid platform, on which high-tech equipment is installed, is designed to work as a passive isolation platform to abate mainly acceleration response of high-tech equipment during an earthquake and to function as an actively controlled platform to reduce mainly velocity response of high-tech equipment under normal working condition. To examine the performance of the hybrid platform, the analytical model of a coupled hybrid platform and building system incorporating with magnetostrictive actuators is established. The simulation results obtained by applying the analytical model to a high-tech facility indicate that the proposed hybrid platform is feasible and effective. Copyright © 2006 John Wiley & Sons, Ltd. [source] Simplified seismic analysis of asymmetric building systemsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2007Jui-Liang Lin Abstract The paper reviews the uncoupled modal response history analysis (UMRHA) and modal pushover analysis (MPA) procedure in the analysis of asymmetric structures. From the pushover curves in ADRS format, showing the relationships of base shear versus roof translation and base torque versus roof rotation, a bifurcating characteristic of the pushover curves of an asymmetric structure is observed. A two-degree-of-freedom (2DOF) modal stick is constructed using lump mass eccentrically placed at the end of beam which is connected with the column by a rotational spring. By converting the equation of motion of a whole structure into 2DOF modal equations, all of the elastic properties in the 2DOF modal sticks can be determined accurately. A mathematical proof is carried out to demonstrate that the 2DOF modal stick is consistent with the single-degree-of-freedom (SDOF) modal stick at elastic state. The bifurcating characteristic of modal pushover curves and the interaction of modal translation and rotation can be considered rationally by this 2DOF modal stick. In order to verify the effectiveness of this proposed 2DOF modal stick, a two-storey asymmetric building structure was analysed by the UMRHA procedure incorporating this novel 2DOF modal sticks (2DMPA) and conventional SDOF modal sticks (SDMPA), respectively. The analytical results are compared with those obtained by nonlinear response history analysis (RHA). It is illustrated that the accuracy of the rotational response histories obtained by 2DMPA is much better than those obtained by SDMPA. Consequently, the estimations of translational response histories on flexible side (FS) and stiff side (SS) of the building structure are also improved. Copyright © 2006 John Wiley & Sons, Ltd. [source] Tuned mass dampers for response control of torsional buildingsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2002Mahendra P. Singh Abstract This paper presents an approach for optimum design of tuned mass dampers for response control of torsional building systems subjected to bi-directional seismic inputs. Four dampers with fourteen distinct design parameters, installed in pairs along two orthogonal directions, are optimally designed. A genetic algorithm is used to search for the optimum parameter values for the four dampers. This approach is quite versatile as it can be used with different design criteria and definitions of seismic inputs. It usually provides a globally optimum solution. Several optimal design criteria, expressed in terms of performance functions that depend on the structural response, are used. Several sets of numerical results for a torsional system excited by random and response spectrum models of seismic inputs are presented to show the effectiveness of the optimum designs in reducing the system response. Copyright © 2002 John Wiley & Sons, Ltd. [source] Asthma Hospitalization Rates Among Children, and School Building Conditions, by New York State School Districts, 1991-2001JOURNAL OF SCHOOL HEALTH, Issue 8 2006Erin Belanger This study examined patterns of asthma hospitalization and possible factors contributing to asthma hospitalizations, including sociodemographics and school environmental factors, among school-age children (5-18 years) in New York State (NYS) over an 11-year period (1991-2001). Asthma hospitalization data from the Statewide Planning and Research Cooperative System and the 1990 and 2000 census population files were geocoded into NYS school districts statewide, and school district asthma hospitalization rates were then calculated. Building Condition Survey for each school was then utilized to create summary measures of school building conditions for each school district. Hospitalization rates were linked to district school building conditions by using logistic regression analysis that controlled for poverty. Calculation of time trends revealed overall declines in asthma rates among school-age children for NYS from 1991 to 2001. This general decline was found in each sociodemographic group. The mean rate for NYS from 1991 to 2001 was 27/10,000. Poorly rated building systems that were significantly associated with increased school district asthma hospitalization rates were roofing (odds ratio [OR] = 1.76; 95% confidence interval [CI95] = 1.13-2.74), windows (OR = 1.66; CI95= 1.08-2.54), exterior walls (OR = 2.24; CI95= 1.31-3.83), floor finishes (OR = 1.75; CI95= 1.14-2.69), and boiler/furnace (OR = 1.71; CI95= 1.99-2.94). This does not indicate a definite link between these systems and asthma hospitalizations since the available building system information is very general and crude. (J Sch Health. 2006;76(8):408-413) [source] Thermoaktive Bauteilsysteme mit integrierten Phasenwechselmaterialien , eine SimulationsstudieBAUPHYSIK, Issue 1 2007Doreen Kalz Dipl.-Ing. Gegenstand der vorliegenden Arbeit ist die Analyse und Evaluierung von thermoaktiven Bauteilsystemen (TABS) und einem Nachtlüftungskonzept hinsichtlich des thermischen Raumkomforts auf Grundlage einer modellbasierten Simulationsstudie. Das Gebäude- und Anlagenmodell wurde in der Simulationsumgebung ESP-r mit Meßdaten aus Experimenten in einem Niedrigenergie-Bürogebäude validiert. Die Untersuchung umfaßt: Betonkerntemperierung (BKT), Kapillarrohrmatten ohne und mit 20% mikroverkapselten latenten Wärmespeichermaterialien (PCM) im Deckenputz. Zentrale Ergebnisse sind: Die Konditionierung mit Kapillarrohrmatten ermöglicht ein zufrieden stellendes Raumklima vergleichbar mit BKT, die Verwendung von PCM trägt entscheidend zur Reduzierung der Raumtemperaturen bei und der optimale Schmelzbereich des PCM-Speichers liegt in dieser Untersuchung bei 19 bis 22 °C. Thermo-active building systems using phase-change materials , a simulation study. The objective of this study aims at analyzing and evaluating thermo-active building systems as well as a night ventilation concept with respect to thermal interior comfort by means of a simulation study. Preliminary experiments in a low-energy office building facilitate the calibration of the simulation model in ESP-r. In particular, the analysis was carried out for (i) concrete core conditioning, (ii) grid conditioning without and (iii) with 20% of micro-encapsulated latent heat storage materials (PCM) applied to the ceiling. The central conclusions of this study are: (1) Grid conditioning provides a satisfactory room condition comparable with concrete core conditioning, (2) the application of PCM contributes to a reduced operative room temperature, and (3) in this study PCM with a melting range of 19 to 22 °C is most favorable. [source] | ||||||||||