• Journal of Welding and Joining
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• v.30 no.1
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• pp.72-77
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• 2012

Recently, according to the increase of income and development of quality of life, the leisure industry has been developed. In particular, the interest of design and manufacture technology of leisure yacht has significantly increased. However, domestic market of leisure ships is currently in its initiating stage. So research and development for structural strength of leisure yacht need to be investigated. In this study, lug of yacht's mast which is known for a critical damage region is explicitly considered. This paper deals with the estimation of stress concentration factors (SCFs) for lug of yacht's mast depending on dimensions of lug using hot spot stress. Also, SCF formulae is suggested using parametric study.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.121-123
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• 2008

The PV modules are affected by heat. The hotter the PV module, the lower the power output, then the life time will be short. If the cell temperature rises above a certain limit the encapsulating materials can be damaged, and this will degrade the performance of the PV module. This is called the ‘hot spot’ formation. This paper presents that the PV module temperature can be estimated by using a thermal analysis program, and demonstrates the thermal characteristics of the PV module.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.1-14
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• 2011

In order to determine temporal changes of the urban landscape, interdependence and interaction among geo-spatial objects can be analyzed using GIS analytic methods. In this study, to investigate changes in the landscape structure of the Namyangju area, the size and shape of landscape patches, and the distance between the patches were analyzed with the Spatial Autocorrelation Method. In addition, both global and local spatial autocorrelation analyses were conducted. The results of global Moran's I revealed that both patch size and shape index transformed to a more dispersed pattern over time. Next, the local Moran's I of patch size in all time series determined that almost all patches were of a high-low pattern. Meanwhile, the local Moran's I of the shape index was found to have changed from a high-high pattern to a high-low pattern in time series. Finally, as time passes, the number of hot spot patches about size and shape index had been decreased according to the results of hot spot analysis. These changes appeared around the development projects in the study area. From the results of this study, degradation of landscape patches in Namyangju were ascertained and their specific areas were delineated. Such results can be used as useful data in selecting areas for conservation and for preparing plans and strategies in environmental restoration.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.113-120
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• 2010

The use of Concrete filled circular hollow steel section (CFCHS) members in bridge design is a relatively new concept. The most important part of the design and durability of such structures is the design and the construction of the joints. In the design of recently constructed steel-concrete composite bridges using CFCHS truss girders for the main load carrying structure, the fatigue verification of the tubular spatial truss joints was a main issue. Welded CFCHS joints are very sensitive to fatigue because the geometric discontinuities of the welds lead to a high stress concentration. New research done on the fatigue behaviour of such joints has focused on CFCHS N-joints, directly welded, with finite element analysis method. A commercial software, ABAQUS, is adopted to perform the finite element analysis on the N-joints. This paper is main focused on these topics, including hot spot stress.

• Korean Journal of Psychosomatic Medicine
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• v.32 no.2
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• pp.70-76
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• 2024

Objectives : Among the various risk factors for suicide, geographic factors have different effects on males and females. This study aimed to identify differences between genders in spatiotemporal dependence and spatiotemporal patterns of suicide mortality over the preceding decade. Methods : This research analyzed the age-adjusted suicide mortality rate per 100,000 population, spanning from 2012 to 2021, for intentional suicides across each administrative district (229 Si, Gun, Gu) in Korea. Data were sourced from the National Statistical Office of the Korean Statistical Information Service. The Moran's I index for spatial autocorrelation of the suicide mortality rates was computed. An emerging hot spot analysis was conducted to examine the community-level spatiotemporal distribution patterns, thus providing insight into the regional clustering characteristics that reflect the temporal-spatial clusters of suicide mortality rates. Results : TIn males, the Moran's I indices were almost above 0 (p-value<0.05) for most years, indicating significant spatial autocorrelation. Conversely, no significant regional clustering was observed among females during the same period. The emerging hot spot analysis, focusing on the temporal trends in the spatial distribution of male suicide mortality rates from 2012 to 2021, identified two distinct time series patterns and a total of 12 hot spot areas: seven new spots and five sporadic spots. Conclusions : This study is the first to intuitively demonstrate the disparities in spatiotemporal dependencies and patterns of suicide mortality rates in Korea between genders. The findings highlight the necessity for tailored suicide prevention strategies that are sensitive to gender differences.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.397-408
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• 2013

The purpose of this study is to analyze water cycle area ratio and spatial evaluation of water cycle in urban area of Changwon-si, Gyeongsangnam-do. Water cycle area ratio are analyzed by using spatial data of land-cover and land-use, and Hot spot analysis of GIS program was used for spatial evaluation of water cycle. The results are as below. Firstly, the high water cycle area ratio areas were forests, parks, and rivers, but urban areas covered asphalt and concrete were low under 40%. Public institutions and co-residential of urban areas were higher than others because of high area ratio of pervious land-cover. Spatial evaluation of water cycle was analyzed to vulnerable areas there are dense residential and commercial area. These areas are really occurring frequently flooding and immersion, therefore, is required water management facilities and improvement of land-cover from impervious to pervious. In the future, it will require additionally analysis of water cycle area ratio supplemented data of water management facility and ground water.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.39-53
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• 2014

The Korean population is aging rapidly and a disproportionate share of older people(aged 65 and older) lives in rural areas. The rural population is aging more rapidly than the population in urban area. However, the majority of studies on aging population focuses on an urban area rather than a rural area. Rural areas have been alienated from the priority of the national policy. For these reasons, this study is to show the level of population aging and to analyze the spatial spillover patterns of aging population in rural areas for the establishment of localized policy on population aging. The main findings of this study can be summarized as follows. First, the level of population aging varies in different localities such as socio-economic and locational characteristics. Secondly, there are distinct differences between hot spot region(clustering of high aging index) and cold spot region(clustering of low aging index) in spatio-temporal spillover patterns. This study intends to suggest an useful information to establish the area-specific policy on aging population through the results of analysis.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.100-109
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• 2022

Large-scale urban concentration of population and vehicles due to economic growth in Korea has been causing serious urban transport problems. Although the collection of congestion pricing has been evaluated as the most effective transportation policy to alleviate traffic demand, its effectiveness is very limited as it was just executed around congested points or along main arterial roads. This study derived dynamic congestion zones with the average travel speed of 206 traffic analysis zones in Busan Metropolitan City to propose a dynamic congestion pricing collection system by employing Space-Time Cube Analysis and Emerging Hot Spot Analysis. As a result, dynamic hot spots were formed from 7h to 24h and particularly, traffic congestion was severely deteriorated from 18h to 20h around Seomyeon and Gwangbok-dong. Therefore, it is expected that the effect of dynamic congestion pricing will be maximized in managing traffic demand in the city center.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.573-580
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• 2007

This paper presents the numerical estimation of the fatigue life for the frame box's welded parts of the marine vessel engine S60MC-C. The time-variations of the effective stresses at the critical points during a piston cycle are computed through the finite element analysis, by applying the dynamic loadings that were analytically derived in the previous paper. The fatigue lives of the welded parts are estimated by making use of the hot-spot stress extrapolation and the Palmgren-miner cumulative damage rule.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.256-260
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• 2015

In this paper, achieved rise temperature distribution about degradation phenomenon of 24 MVA distribution cast resin transformer using CFD(Computational Fluid Dynamics). Usually, life of transformer is depended on temperature distribution of specification region than thermal special quality of transformer interior. Specially, life of transformer by decline of dielectric strength decreases rapidly in case rise by strangeness transformer interior hot spot temperature value permits. Because calculating high-voltage(HV) winding and low-voltage(LV) winding of cast resin transformer and Joule's loss of core for improvement these life, forecasted heat source, and HV winding and LV winding of cast transformer rise temperature distribution of core for supply of electric power and temperature distribution of highest point on the basis of the results. Also, calculated temperature rise limit of cast resin transformer and permission maximum temperature using analysis by electromagnetic heat source. Calculated and forecasted rise temperature distribution by heat source of thermal analysis with calculated result.