• Asian Journal of Innovation and Policy
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• v.10 no.2
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• pp.249-273
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• 2021

While many criminal studies have focused on the motivation of offenders and avoidance of victimization in the micro perspective, there have been a number of theoretical developments emphasizing space as a direct factor that influences the incidence of crime. The main purpose of this study is to analyze the effects of regional characteristics and violent crime incidence in Korea. Applying diverse spatial econometrics models that have less been utilized in the crime literature, this study finds an important association between spatial accessibility and crime incidence. The results suggest that the type of predominant business and the level of road accessibility affect the vulnerability of areas with respect to the incidence of violent crime. This study concludes with some important implications for urban planners and policymakers with respect to crime control and prevention.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.159-166
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• 2004

The capacity concept presented in the Highway Capacity Manual is for steady-state traffic flow assuming that there is no restriction in downstream flowing, which is traditionally used for planning, design, and operational analyses. In the congested traffic condition, the control objective should be to keep the congested regime from growing and to recover the normal traffic condition as soon as possible. In this control case, it is important to predict the spatial-temporal pattern of congestion evolution or dissipation and to estimate the throughput reduction according to the spatial-temporal pattern. In this context, the new concept of dynamic capacity for managing congested traffic is developed in terms of spatial-temporal evolution of downstream traffic congestion and in view of the 'input' concept assuming that flow is restricted by downstream condition rather than the 'output' concept assuming that there is no restriction in downstream flowing (e.g. the mean queue discharge flow rate). This new capacity is defined as the Maximum Sustainable Throughput that is determined based on the spatial-temporal evolution pattern of downstream congestion. And the spatial-temporal evolution pattern is estimated using the Newell's simplified q-k model.

• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.80-87
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• 2022

Objectives: Dengue remains hyperendemic in Malaysia despite extensive vector control activities. With dynamic changes in land use, urbanisation and population movement, periodic updates on dengue transmission patterns are crucial to ensure the implementation of effective control strategies. We sought to assess shifts in the trends and spatial patterns of dengue in Kelantan, a north-eastern state of Malaysia (5°15'N 102°0'E). Methods: This study incorporated data from the national dengue monitoring system (eDengue system). Confirmed dengue cases registered in Kelantan with disease onset between January 1, 2016 and December 31, 2018 were included in the study. Yearly changes in dengue incidence were mapped by using ArcGIS. Hotspot analysis was performed using Getis-Ord Gi to track changes in the trends of dengue spatial clustering. Results: A total of 10 645 dengue cases were recorded in Kelantan between 2016 and 2018, with an average of 10 dengue cases reported daily (standard deviation, 11.02). Areas with persistently high dengue incidence were seen mainly in the coastal region for the 3-year period. However, the hotspots shifted over time with a gradual dispersion of hotspots to their adjacent districts. Conclusions: A notable shift in the spatial patterns of dengue was observed. We were able to glimpse the shift of dengue from an urban to peri-urban disease with the possible effect of a state-wide population movement that affects dengue transmission.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.259-268
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• 2004

For supporting Interoperability among heterogeneous data sources in different geographic information systems, it is required to use open API like OGIS OLE DB Proposed in OGC. The OLE/COM Implementation Specification of OGIS only provides interfaces to discover and access spatial data, but does not support interfaces for updating distributed spatial data. To solve this problem, we propose and add interfaces for updating spatial objects distributed over heterogeneous data sources and examining the consistency of spatial relationships between updated objects. We also devise a 2-phase commit protocol based on spatial relationships in order to guarantee the consistency of updated objects. To justify the update scheme using the proposed Interfaces and 2-phase commit prototype we design and implement a prototype system for updating distributed spatial objects.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.1010-1017
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• 2013

Two-axial electrodynamic forces generated on a conductive plate by a partially shielded magnet wheel are strongly coupled through the rotational speed of the wheel. To control the spatial position of the plate using magnet wheels, the forces should be handled independently. Thus, three methods are proposed in this paper. First, considering that a relative ratio between two forces is independent of the length of the air-gap from the top of the wheel, it is possible to indirectly control the in-plane position of the plate using only the normal forces. In doing so, the control inputs for in-plane motion are converted into the target positions for out-of-plane motion. Second, the tangential direction of the open area of the shield plate and the rotational speed of the wheel become the new control variables. Third, the absolute magnitude of the open area is varied, instead of rotating the open area. The forces are determined simply by using a linear controller, and the relative ratio between the forces creates a unique wheel speed. The above methods were verified experimentally.

• Journal of Korean Association for Spatial Structures
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• v.15 no.3
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• pp.51-60
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• 2015

Recently, the concept of damped outrigger system has been proposed for tall buildings. But, structural characteristics and design method of this system were not sufficiently investigated to date. In this study, the dynamic response control performance of outrigger damper has been analyzed. To this end, a simplified analysis model with outrigger damper system has been developed. An artificial wind of 1000 seconds with 0.1 second time steps was generated by using a Kaimal spectrum. Analysis results show that outrigger damper system is more effective up to 20-23% in the control of dynamic response compared to conventional outrigger system. The increase of outrigger damper capacity usually results in the improved control performance. However, it is necessary to select that proper stiffness and damping values of the outrigger damper system because, the outrigger damper having large capacity is result in heavy financial burden.

• Journal of Korean Association for Spatial Structures
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• v.16 no.1
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• pp.95-104
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• 2016

Recently, the concept of damped outrigger system has been proposed for tall buildings. But, structural characteristics and design method of this system were not sufficiently investigated to date. In this study, the dynamic response control performance of outrigger damper has been analyzed. To this end, a simplified analysis model with outrigger damper system has been developed. Use the El Centro seismic(1940, NS) analysis was performed. Analysis results, on the top floor displacement response to the earthquake response, did not have a big effect. However, acceleration response control effect was found to be excellent. The increase of outrigger damper capacity usually results in the improved control performance. However, it is necessary to select that proper stiffness and damping values of the outrigger damper system because, the outrigger damper having large capacity is result in heavy financial burden.

• Journal of Korean Association for Spatial Structures
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• v.14 no.3
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• pp.75-84
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• 2014

When adjacent tall buildings experience earthquake excitation, structural pounding may happen. In order to mitigate seismic pounding damage to adjacent structures, many studies have been done to date. Tuned mass dampers (TMD) are widely used for reduction of dynamic responses of building structures subjected to earthquake excitations. If a TMD is shared between adjacent buildings and it shows good control performance, it will be effective and economic means to reduce seismic responses of adjacent structures. In this study, control performance of a shared tuned mass damper (STMD) for seismic response reduction of adjacent buildings has been evaluated. For this purpose, two 8-story example buildings were used and multi-objective genetic algorithms has been employed for optimal design of the stiffness and damping parameters of the STMD. Based on numerical analyses, it has been shown that a STMD can effectively control dynamic responses and reduce the effect of pounding between adjacent buildings subjected to earthquake excitations in comparison with a traditional TMD.

• Journal of Korean Association for Spatial Structures
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• v.18 no.4
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• pp.41-48
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• 2018

Recently, the concept of an outrigger damper system with a damper added to the existing outrigger system has been developed and applied for dynamic response control of high-rise buildings. However, the study on the structural characteristics and design method of Outrigger damper system is in the early stages. In this study, a 50 story high - rise building was designed and an outrigger damper system with viscoelastic damper was applied for wind response control. The time history analysis was performed by using the kaimal spectrum to create an artificial wind load for a total of 1,000 seconds at 0.1 second intervals. Analysis of the top horizontal maximum displacement response and acceleration response shows that outrigger damper systems are up to 28.33% and 49.26% more effective than conventional outrigger systems, respectively. Also, it is confirmed that the increase of damping ratio of dampers is effective for dynamic response control. However, since increasing the damping capacity increases the economic burden, it is necessary to select the appropriate stiffness and damping value of the outrigger damper system.

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.43-50
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• 2021

A tilted tall building is actively constructed as landmark structures around world to date. Because lateral displacement responses of a tilted tall building occurs even by its self-weight, reduction of seismic responses is very important to ensure structural safety. In this study, a smart tuned mass damper (STMD) was applied to the example tilted tall building and its seismic response control performance was investigated. The STMD was composed of magnetorheological (MR) damper and it was installed on the top floor of the example building. Control performance of the STMD mainly depends on the control algorithn. Fuzzy logic controller (FLC) was selected as a control algorithm for the STMD. Because composing fuzzy rules and tuning membership functions of FLC are difficult task, evolutionary optimization algorithm (EOA) was used to develop the FLC. After numerical simulations, it has been seen that the STMD controlled by the EOA-optimized FLC can effectively reduce seismic responses fo the tilted tall building.