The gated community: residents' crime experience and perception of safety behind gates and fences in the urban area

The primary purpose of the study is to explore the connections between residents' perception of safety and their crime experience, and the existence of gates and fences in multi-family housing communities in urban areas. For cultivating discussions regarding the connections between gated community territory, safety, and crime experience, this study classifies apartment communities according to the conditions of their gating and fencing: gated communities, perceived gated communities, and non-gated communities. It investigates residents' perceptions of safety and their opinions and managers' opinions on gated territory and safety. The major findings from the surveys are: Residents felt safer in gated communities than in non-gated communities. Residents' perceptions of safety in perceived gated communities were similar to those in gated communities. These results reflected the territoriality issue for improving residents' perceived safety in apartment communities. Residents' perceptions of safety in architectural spaces showed that residents' fear of crime in public and semi-public spaces must first be addressed in order to ease residents' fear of crime in an apartment territory. The reality of crime in apartment communities differed from residents' perceptions of safety. Gated community residents reported a higher crime rate than nongated community residents. In addition to gates and fences that define apartment territory, such elements as patrol services, bright lighting, direct emergency buttons, and visual access to the local police were indicated as the important factors for improving residents' perceived safety. Some architectural factors and demographic factors exhibited statistical correlations with residents' perceptions of safety. Those were types of communities, dwelling floor level, educational attainment, family size, and annual income. For predicting residents' perceptions of safety in their apartment territory, multiple regression models were obtained and residents' neighborhood attachment was also considered in the multiple regression models. The apartment community managers emphasized direct maintenance issues and residents' social contact with neighbors for improving residents' perceived safety. In conclusion, design and managerial suggestions for safer communities were proposed. For creating safer multi-family housing communities, territoriality and related architectural conditions and managerial considerations and residents' participations are emphasized. The concept of community programming for safer multi-family housing communities is suggested

Magnon topology and thermal Hall effect in trimerized triangular lattice antiferromagnet

The non-trivial magnon band topology and its consequent responses have been extensively studied in two-dimensional magnetisms. However, the triangular lattice antiferromagnet (TLAF), the best-known frustrated two-dimensional magnet, has received less attention than the closely related Kagome system, because of the spin-chirality cancellation in the umbrella ground state of the undistorted TLAF. In this work, we study the band topology and the thermal Hall effect (THE) of the TLAF with (anti-)trimerization distortion under the external perpendicular magnetic field using the linearized spin wave theory. We show that the spin-chirality cancellation is removed in such case, giving rise to the non-trivial magnon band topology and the finite THE. Moreover, the magnon bands exhibit band topology transitions tuned by the magnetic field. We demonstrate that such transitions are accompanied by the logarithmic divergence of the first derivative of the thermal Hall conductivity. Finally, we examine the above consequences by calculating the THE in the hexagonal manganite YMnO$_3$, well known to have anti-trimerization.Comment: 6 + 7 pages, 3 + 5 figures, 0 + 1 table; Journal reference adde

On Hyperelastic Crease

We present analyses of crease-formation and stability criteria for incompressible hyperelastic solids. A generic singular perturbation over a laterally compressed half-space creates a far-field eigenmode of three energy-release angular sectors separated by two energy-elevating sectors of incremental deformation. The far-field eigenmode braces the energy-release field of the surface flaw against the transition to a self-similar crease field, and the braced-incremental-deformation (bid) field has a unique shape factor that determines the creasing stability. The shape factor, which is identified by two conservation integrals that represent a subsurface dislocation in the tangential manifold, is a monotonically increasing function of compressive strain. For Neo-Hookean material, when the shape factor is below unity, the bid field is configurationally stable. When the compressive strain is 0.356, the shape factor becomes unity, and the bid field undergoes a higher-order transition to a crease field. At the crease-limit point, we have two asymptotic solutions of the crease-tip folding field and the leading-order far field with two scaling parameters, the ratio of which is determined by matched asymptotes. Our analyses show that the surface is stable against singular perturbation up to the crease limit point and becomes unstable beyond the limit. However, the flat state is metastable against a regular perturbation between the crease limit point and wrinkle critical point, which is a first-order instability point. We introduced a novel finite element method for simulating the bid field with a finite domain size. For Gent model, the strain-stiffening alters the shape factor dependence on the compressive strain, raising crease resistance. The new findings in crease mechanisms will help study ruga mechanics of self-organization and design soft-material structures for high crease resistance.Comment: 42 pages, 6 figure

Effect of spatial and temporal factors on occupants' blind use behaviors in multifamily residential buildings

Existing studies show that occupants’ behavior contributes to fluctuations in energy consumption of residential units within the same building configuration. Window blinds are one of the interior design elements that the occupants use to control indoor environmental conditions. The way that occupants adjust their blinds could affect the energy performance of buildings. Thus, the purpose of this research was to identify spatial and temporal explanatory variables that correlate with occupants’ use of the blinds and determine whether those variables relate to building design and surrounding sites. Data were collected by observing how occupants in apartment buildings located in a multifamily residential complex adjust their blinds. Descriptive statistics were used to define the effect of floor level, window orientation, day of observation, hour of observation, and weather conditions on the blind status. In addition, a generalized linear mixed model was used to predict the effect of floor level and window orientation on the occupants’ adjustment of blinds. The results revealed that occupants’ use of the blinds correlated significantly with spatial factors, such as the apartment buildings’ floor level and windows’ orientation. Interesting blind use patterns were related to temporal factors, such as the day and hour of observation.Peer reviewedDesign, Housing and Merchandisin

A Study on the Factors That Influence the Acoustic Performance of a Steel Stud Wall Assembly

With the recent introduction of light gauge steel framing systems in the concrete-dominated Korean construction industry, more buildings are built with drywall that is mainly composed of steel studs and gypsum boards. While load-bearing steel studs are extensively applied in residential construction, nonload-bearing steel studs are applied in various building fields such as commercial, educational, as well as residential. As building projects involving steel stud walls are becoming to increase, higher demands in performance are requested from architects and builders, especially in the field of sound performance. A series of acoustic test were performed in the nationally certified sound-testing laboratory at Korean Institute of Construction Technology (KICT) in order to evaluate and analyze factors that influence acoustic performance of steel stud wall assemblies. Factors affecting the acoustic performance of steel stud walls that are analyzed in this paper include among others, the composition and structure of steel studs, stud spacing, stud thickness, stud size, use of resilient channel, screw spacing, etc. Factors relating to gypsum boards that were tested as part of the evaluation of acoustic performance are not included in this paper. Results of this study, which is co-funded by 3 major gypsum board companies in Korea, are being used to develop stud wall assemblies that meet the required acoustic performance for unit-to-unit separating walls, as well as present architects and builders with a better understanding on the sound behavior of steel stud drywall

Local Hall effect in hybrid ferromagnetic/semiconductor devices

We have investigated the magnetoresistance of ferromagnet-semiconductor devices in an InAs two-dimensional electron gas system in which the magnetic field has a sinusoidal profile. The magnetoresistance of our device is large. The longitudinal resistance has an additional contribution which is odd in applied magnetic field. It becomes even negative at low temperature where the transport is ballistic. Based on the numerical analysis, we confirmed that our data can be explained in terms of the local Hall effect due to the profile of negative and positive field regions. This device may be useful for future spintronic applications.Comment: 4 pages with 4 fugures. Accepted for publication in Applied Physics Letter