bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complex engineered, organizational and natural systems
Authors: Rouse William B. 
Published: June 2007

AbstractThis paper describes an effort to determine the rationale and content for a research agenda in complex systems. This effort included a workshop conducted with 50 thought leaders in complex engineered, organizational, and natural systems. The results of this workshop were subsequently presented to seven groups in academia and industry across the United States. In this way, additional comments, suggestions, and insights were gained from roughly 200 participants in these presentations. The objectives of these eight events were to understand the underlying issues that cause us to perceive a system to be complex, and formulate a set of fundamental research questions whose pursuit would advance abilities to address these issues. © 2007 Wiley Periodicals, Inc. Syst Eng: 260–271, 2007
Ductility factors of symmetrical structures with restricted inelasticity
Authors: Georgoussis George K. 
Published: June 2007

AbstractA simple elasto‐plastic analysis of symmetrical buildings composed of different types of bents is presented. Plasticity in bents is assumed to be restricted to the beams, where significant curvature ductility factors may be attained without loss of strength, and the behaviour of inelastic structures may be traced from elastic to ultimate deflections on the grounds that the external load is monotonically increasing with an invariant shape throughout the loading history. The outlined procedure is based on the concept of the continuous medium and a comprehensive consideration of the structural post‐elastic behaviour of common mixed‐bent‐type buildings is possible by means of parameter variations. Therefore it is suitable for a simple pushover elasto‐plastic analysis in a parametric form. The proposed method of analysis is based on the technique of decomposing a cantilever structural system into two components: a flexural and a shear–flexure subsystem. With this decomposition, not only the axial deformations in the column members of all bents are taken into account in the calculation of deflections, but also different types of bents may be combined in symmetrical buildings. Design charts relating the overall ductility factor with the maximum rotation ductility factor at the ends of the beams are presented for the case of a triangularly distributed external load, together with the formulation that defines the post‐elastic load–deflection curve. These data may be found useful for practising engineers at the stage of a preliminary structural application. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic analysis of inelastic moment‐resisting frames Part I: Modified force analogy method for end offsets
Authors: Wong Kevin K. F. , Wang Zhe 
Published: June 2007

AbstractAn analytical method of performing inelastic structural dynamic analysis based on the force analogy method to study real moment‐resisting frames with plastic hinge offsets from member ends and rigid panel zones is proposed. New stiffness matrices used in the force analogy method for members with two ends being rigid are theoretically derived using the unit displacement method. Through static condensation, each term in the stiffness matrices is found to be modified simply through multiplying by a scale factor. This is an enhancement to the original force analogy method or other conventional methods, where the condensed form reduces the size of the structural problem by eliminating the unnecessary additional degrees of freedom that must be placed at the plastic hinges. But more importantly, this is a significant improvement on other conventional methods where the present inelastic analysis procedure is more of a theoretical nature rather than numerical. Numerical simulation for seismic analysis is performed on a single degree of freedom system, and the results show that plastic hinge end offsets have significant effects on the seismic response and therefore they should be carefully considered in dynamic analysis. The companion paper further discusses the influence of panel zone deformation on the dynamic response based on the method proposed in this part of the research. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic analysis of inelastic moment‐resisting frames Part II: Energy dissipation in deformable panel zones
Authors: Wong Kevin K. F. , Wang Zhe 
Published: June 2007

AbstractThe simple analytical method developed in the companion paper is applied to study the dynamic behavior and energy dissipation of inelastic structures with panel zone deformation using rotational springs. Both shear deformation and inelastic behaviors of the panel zone are modeled using rotational springs to capture the actual vibration characteristics of the overall structural responses. The modified force analogy method with static condensation proposed in the companion paper is employed to study the effects of panel zone deformation on the dynamic behavior of inelastic structures, while rigid end offsets are also included to give a more accurate structural model. Based on this proposed analytical method, numerical simulation is first performed to study the responses of a one‐story one‐bay moment‐resisting frame. Results show that rigidity of panel zones plays a major role in the overall structural responses during earthquake excitations. Numerical simulations are then performed on a multi‐degree of freedom structure to demonstrate the use of the proposed method. Comparison of results between modeling structures with various panel zone rigidities and yield moments in the rotational springs shows that significant differences in both structural responses and energy dissipations exist between the models, and therefore the effects of panel zone deformation should be considered in dynamic analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental and analytical studies on tall buildings with a high‐level transfer story
Authors: Wu Meiliang , Qian Jiaru , Fang Xiaodan , Yan Weiming 
Published: June 2007

AbstractShaking‐table tests of three scaled Plexiglas models of tall buildings with a transfer story at story five, seven or nine, respectively, were carried out. The experimental results show that with increasing transfer story level the natural frequencies of the structures show little change and the change of mode shapes is not significant. The maximum elastic responses of acceleration, interstory drift ratio and base shear force might increase or decrease. Elastic and elasto‐plastic time history analyses of tall buildings with different levels of transfer story were performed to study the seismic behavior of tall buildings with a high‐level transfer story. The analytical results show that for tall buildings with a high‐level transfer story the maximum elastic interstory drift ratios become small at the transfer story. With increasing transfer story level, the maximum ratio of base shear force to total weight, and the maximum elastic and elasto‐plastic interstory drift ratios, might increase or decrease. Reducing the stiffness below the transfer story will increase the interstory drift ratio. Deformations of the floor slab increase the elastic internal forces of support columns near the transfer story. Copyright © 2007 John Wiley & Sons, Ltd.
Dynamic control of structures subjected to constraints
Authors: Lee Eun‐Taik , Chung Heon‐Soo , Eun Hee‐Chang 
Published: June 2007

AbstractThis study presents a dynamic equation of constrained motion and illustrates its validity through a dynamic analysis on the structural control by a constraint. Minimizing a function of the variation in kinetic energy at constrained and unconstrained states with respect to the velocity variation, the dynamic equation is derived and it is shown that the result compares with the generalized inverse method proposed by Udwadia and Kalaba. It is investigated that the responses of a 10‐story building are controlled by a constraint due to the installation of a two‐bar structure. The structural responses are affected by various factors like the length of each bar, damping, stiffness of the bar structure, and the boundary positions between two structures. Under an assumption that the bars have the same mass density, this study determines the optimal boundary positions to minimize the total responses of the structure, and compares the responses and control forces by optimal feedback control with the results. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic isolation columns for earthquake‐resistant structures
Authors: Briman V. , Ribakov Y. 
Published: June 2007

AbstractSeismic isolation is a well‐known trend in earthquake design of structures. It enables a reduction in structural response to earthquakes and minimizes possible damage to buildings. This paper deals with a new constructive solution for seismic isolation, adapted to a structural scheme traditionally used in the Mediterranean region; it is usually presented as an open ground floor with a system of reinforced‐concrete columns, supported on single bases. The best‐known base isolation systems, implemented in existing structures, are elastomeric bearings and friction pendulums. The proposed solution is based on the idea of pendulum suspension brackets installed in seismic isolation columns. The main differences between existing solutions and the proposed one are that the latter requires no additional space for its installation, its lifetime corresponds to that of the structure, and no service is required during the entire period. The proposed solution provides additional damping and, like other base isolation systems, shifts the vibration period of the structure, reducing its spectral response. Since its size is compact, the ground‐floor columns of existing structures with low seismic capacity may easily be replaced by the proposed ones. It yields significant improvement in structural seismic response. Numerical simulation shows that buildings where the proposed system is installed are likely to sustain minimal damage, or none at all, whereas traditionally designed ones may suffer major damage or even collapse due to the same earthquake. Copyright © 2007 John Wiley & Sons, Ltd.
Practical design issues of tuned mass dampers for torsionally coupled buildings under earthquake loadings
Authors: Ueng Jin‐Min , Lin Chi‐Chang , Wang Jer‐Fu 
Published: June 2007

AbstractIn this study, a new design procedure was developed for reducing the dynamic responses of torsionally coupled buildings, particularly existing buildings, under bilateral earthquake excitations, by incorporating the vibration control effectiveness of passive tuned mass dampers (PTMDs) . Some practical design issues such as the optimal location for installation, movement direction and numbers of PTMD are considered in this study. The optimal parameters of the PTMD system are determined by minimizing the mean square displacement response ratio of the controlled degree of freedom between the building with and without PTMDs. In addition, parametric studies of the PTMD planar position and the detuning effect are undertaken to determine their influence on the response control efficacy. The numerical results from two typical multistory torsionally coupled buildings under bidirectional ground accelerations, recorded at the 1979 El Centro earthquake, verify that the proposed optimal PTMDs are more effective and more robust in reducing the building responses. Copyright © 2007 John Wiley & Sons, Ltd.
Robustness of base‐isolated high‐rise buildings under code‐specified ground motions
Authors: Takewaki I. 
Published: June 2007

AbstractThe robustness of base‐isolated high‐rise buildings is investigated under code‐specified ground motions. Friction‐type bearings are often used in base‐isolated high‐rise buildings to make the natural period of those buildings much longer. While additional damping can be incorporated into every story in passive controlled structures with inter‐story type passive members, that can be incorporated into the base‐isolation story only in the base‐isolated building. This fact leads to the property that, as the number of stories of the building becomes larger, the damping ratio reduces. This characteristic may cause some issues in the evaluation of robustness of base‐isolated high‐rise buildings. The purpose of this paper is to reveal the robustness of base‐isolated high‐rise buildings. A kind of inverse problem for the target drift in the base‐isolation story is formulated in order to determine the required quantity of additional viscous damping. It is demonstrated numerically that, as the base‐isolated building becomes taller, the damping ratio becomes smaller and the ratio of the friction‐type bearings in the total damping becomes larger. This may lead to the conclusion that base‐isolated high‐rise buildings have smaller robustness than base‐isolated low‐rise buildings. Copyright © 2007 John Wiley & Sons, Ltd.
The “business intelligence” challenge in the context of regional risk
Authors: Kinsinger Paul C. 
Published: June 2007

AbstractThe world of intelligence is about understanding external factors we cannot control in order to reduce the risk and increase the reward. Indeed, business intelligence (BI) flourishes today in the United States because market economics and, even more important, the way business is done here, pump out information 24‐7‐365 the way a heart on steroids pumps out blood. In this article, I offer an overview of BI within the context of four countries that are the subject of in‐depth study in this issue of Thunderbird International Business Review: Iraq, the United Arab Emirates, Croatia, and Bosnia and Herzegovina. All four nations offer interesting and varied examples for the international manager doing business in countries where risk is often a key factor that must be considered when making business decisions. © 2007 Wiley Periodicals, Inc.
Optimal shape of an elastic rod in flexural – torsional buckling
Authors: Atanackovic T.M. 
Published: June 2007

AbstractOptimal shape of an elastic rod subjected to flexural‐torsional buckling is studied. The rod with constant‐cross section is the strongest rod for the case when a rod is subjected to equal end moments only. For the case when the rod is loaded with compressive force and the moment, optimal shape is determined by numerical integration for several values of parameters. In deriving the optimality conditions, the Pontriyagin's principle was used.
Analytical solution for three‐dimensional stresses in a short length FGM hollow cylinder
Authors: Jabbari M. , Mohazzab A.H. , Bahtui A. , Eslami M.R. 
Published: June 2007

AbstractThis paper presents the general theoretical analysis of three‐dimensional mechanical and thermal stresses for a short hollow cylinder made of functionally graded material. The steady‐state temperature, displacements, and stresses distributions are derived due to the general mechanical and thermal boundary conditions, as functions of radial, circumferential and longitudinal directions. The material properties vary continuously along the thickness direction according to power functions of radial direction. The temperature and Navier equations are solved analytically, using the generalized Bessel function and Fourier series. A direct method of solution of Navier equations is presented.
Effect of Ginkgo biloba Extract (EGb 761) on the Healing of Left Colonic Anastomoses in Rat
Authors: Kisli Erol , Özdemir Hülya , Kösem Mustafa , Sürer Hatice , Ciftçi Ali , Kanter Mehmet 
Published: June 2007

AbstractBackgroundThe aim of this study was to assess the effect of Ginkgo biloba extract (EGb 761) on healing of experimental colonic anastomoses in a rat model.MethodsRats were divided into four groups: postoperative day (POD) 3 untreated control group, POD 3 EGb 761 group, POD 7 untreated control group, and POD 7 EGb 761 group. In the oral EGb 761 groups, the agent was given at 9.6 mg daily per orogastric route using a 4‐F fine feeding catheter. We measured bursting pressures and hydroxyproline content and histologically examined the resected anastomoses on POD 3 and POD 7.ResultsThe bursting pressures increased more in the EGb 761 group than in the untreated control group on POD 3, but this difference was not statistically significant. Hydroxyproline content was higher in the EGb 761 group than in the untreated control group on POD 3, and this difference was statistically significant. Anastomosis bursting pressure values and hydroxyproline contents were significantly higher in the EGb 761 group than in the untreated control group on POD 7. Histological examination showed greater fibroblastic activity in the EGb 761 group than in the untreated control group on POD 3. There was no significant difference in anastomotic polimorphonuclear leukocyte, mononuclear cells and blood vessel neodevelopment between the POD 3 groups, but there was significant difference in fibroblastic activity and blood vessel neodevelopment between the POD 7 groups.ConclusionsThese results showed us that EGb 761 administration resulted in enhanced stability of colonic anastomoses during the first postoperative week.
Asymmetry in reproductive isolation and its effect on directional mitochondrial introgression in the parapatric ground beetles Carabus yamato and C. albrechti
Authors: Takami Yasuoki , Nagata Nobuaki , Sasabe Masataka , Sota Teiji 
Published: June 2007

AbstractSpeciation studies seek to clarify the origin of reproductive isolation, the various mechanisms working from mate recognition through postzygotic stages. Asymmetric effects of isolating barriers can result in asymmetrical gene introgression during interspecific hybridization. The flightless ground beetles Carabus yamato and C. albrechti are distributed parapatrically in Japan, showing repeated asymmetrical introgression of mitochondria from C. albrechti to C. yamato. This pattern suggests that reproductive isolation between these species is strong, but incomplete and asymmetric (i.e., weaker for the cross between a C. albrechti female and a C. yamato male). To test this hypothesis, we conducted interspecific mating experiments in the laboratory. The estimates of total reproductive isolation, which occurred mainly at the premating and postmating/prezygotic stages, were high (isolation index = 0.964 for C. yamato female × C. albrechti male and 0.886 for the reciprocal cross), supporting the hypothesis of strong, but incomplete isolation. However, the observed difference between the reciprocal crosses was not sufficiently large to conclude that it caused directional introgression of mitochondria. Instead, we found asymmetry in individual isolating barriers in the postmating/prezygotic stages that coincided with the prediction, perhaps resulting from morphological mismatch of heterospecific genitalia. Although this asymmetry was compensated for by an inverse asymmetry of isolation in the postzygotic stage, the contribution of these individual barriers to total isolation may change for our expectation when considering females mating with multiple heterospecific males.
A Psychosocial Resource Impairment Model Explaining Partner Violence and Distress: Moderating Role of Income
Authors: Williams Stacey L. , Mickelson Kristin D. 
Published: June 2007

AbstractThis study examines the role of income in a psychosocial resource impairment model that explains partner violence and distress. Using data from a nationally representative sample, we test whether psychosocial resources of social support and self‐esteem operate differently in four income groups (poor, “working”‐poor, middle and upper‐income). Structural equation modeling shows that among women considered working‐poor, low self‐esteem is relevant for the process through which violence becomes linked to distress. Women of upper‐income appear distinct with negative interactions serving as sole mediator of violence and distress. Other findings indicate impaired support may mediate the violence and distress relation for women, regardless of income. Overall, income partially moderates the impact of partner violence on distress, suggesting social contexts should be considered when examining the effects of violence.
Measuring Neighborhood: A Conundrum for Human Services Researchers and Practitioners
Authors: Nicotera Nicole 
Published: June 2007

AbstractThis article contributes to the knowledge base of neighborhood intervention and research by reviewing the myriad ways the constructneighborhoodis operationalized. The interdisciplinary review presents a critical examination of each measurement genre from quantitative to qualitative. The discussion of neighborhood measures includes (a) census and other administrative data, (b) windshield surveys, (c) rating scales, (d) structured/unstructured interviews (including ethnographies), (e) residents' written descriptions, (f) photographs, (g) drawings, and (h) mixed method constructions. When pertinent, the role of children's voices in these measures is discussed. In addition, the conceptual nature ofneighborhoodis examined from the perspective of environment and place. This environment–place duality is presented as a framework for choosing the type of measure one plans to use for research or practice. Conclusions suggest that research and practice are enhanced by building bridges between measures representing environment and measures representing place. Such bridges offer opportunities to develop interventions that are viable for creating lasting change.
In‐line measurement of tempered cocoa butter and chocolate by means of near‐infrared spectroscopy
Authors: Bolliger Stefan , Zeng Yuantong , Windhab Erich J. 
Published: June 2007

AbstractIn the present work cocoa butter and chocolate were precrystallized by means of a newly developed shear crystallizer. The shear crystallizer was integrated into a circular loop. The handling of precrystallized cocoa butter showed a high dependency on the timing of applied analysis. Differential scanning calorimetry, calorimetry, rheometry, and in‐line near‐infrared (NIR) were all directly influenced by the fat crystal structure. Nevertheless, for cocoa butter it was shown that mechanical energy input (rpm) had a significant influence on viscosity, melting enthalpy, and slope at the second point of inflection of a temper curve. Experiments with cocoa butter at constant exit temperature showed a linear increase of viscosity between 0.1 and 0.8 Pa·s in the range of 300 to 1300 rpm. Melting enthalpy increased in the same rpm interval from 0.02 to 2.5 J/g. Solidification time (from 4.5 to 0.5 min) and slope (from 0.82 to 0.15, second point of inflection of temper curve) consequently decreased (both with exponential approximation). For cocoa butter, slope and solidification time correlated linearly whereas solidification time and viscosity followed a power law fit. This proved that defined relationships exist between rheological data and data from temper curve measurements. Viscosity was linearly dependent on crystal content. By means of NIR spectroscopy good correlation models for cocoa butter viscosity, enthalpy (crystal content), and slope values were found. For precrystallized chocolate, analytical values such as viscosity and slope values were detected off‐line and used for calibration of NIR spectroscopy.