• 한국지구과학회지
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• 제24권1호
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• pp.1-6
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• 2003

In this work, the present concentration levels of total gaseous mercury (TGM) are compared among three East Asian countries, Korea, China, and Japan. Comparison of Hg distribution patterns was made by selecting representative figures for each type of land use among those three countries. The results of the analysis indicate that Hg concentrations within a country can fall into a wide range due probably to the diversity of source processes. It is seen that the urban areas of China and Japan generally exhibit large spatial variability with notably high Hg levels (above 10 ng m$^{-3}$), compared to their Korean counterparts. Although the presence of high Hg levels in Chinese locations can be accounted for by the major man-made source processes (e.g., the use of coal), the causes of unexpectedly high Hg data in Japanese sites appear to be rather complicated. The Hg concentration levels in relatively remote locations however show much reduced values, above 3 ng m$^{-3}$, which is still higher than the typical background concentrations of 1 to 2 ng m$^{-3}$ in Europe or America. Considering that the presence of unusually high Hg levels in urban areas of Asia is the consequence of man-made activities, the prevalence of excessively high Hg values in certain regions of the Asian continent needs further research to accurately assess the fundamental picture of Hg geochemistry in the East Asia.

• 한국컴퓨터산업학회논문지
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• 제2권11호
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• pp.1373-1382
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• 2001

이동통신 텔레트래픽 모델은 Network Traffic 모델과 Traffic Source 모델이라는 두 개의 하부모델로 구성된다. 본 논문에서는 기지국이 설치되어 있는 지역 특성을 고려한 traffic source 모델을 제시하고, 이동통신 트래픽 시뮬레이터인 MobCall을 구현하였다. MobCall은 사용자 이동성을 각 지역별 차량 평균 속도와 수송분담율을 적용하고 있다. 구현된 MobCall을 이용하여 서울 도심 주거지역과 상업지역에서의 누적 발생 호 수, 교통량에 따른 핸드오프 율, 고속도로에서의 핸드오프 율, 그리고 호 점유 시간 변화에 따른 핸드오프 율을 결과로 제시하였다. MobCall은 기지국에서 사용자 호 패턴에 따른 동적 핸드오프 버퍼링과 같은 기능적 요소를 설계 단계에서 고려할 수 있다.

• Structural Engineering and Mechanics
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• 제21권4호
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• pp.407-422
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• 2005

Plate elements in fully profiled sandwich panels are generally subjected to local buckling failure modes and this behaviour is treated in design by using the conventional effective width method for plates with a width to thickness (b/t) ratio less than 100. If the plate elements are very slender (b/t > 1000), the panel failure is governed by wrinkling instead of local buckling and the strength is determined by the flexural wrinkling formula. The plate elements in fully profiled sandwich panels do not fail by wrinkling as their b/t ratio is generally in the range of 100 to 600. For this plate slenderness region, it was found that the current effective width formula overestimates the strength of the fully profiled sandwich panels whereas the wrinkling formula underestimates it. Hence a new effective width design equation has been developed for practical plate slenderness values. However, no guidelines exist to identify the plate slenderness (b/t) limits defining the local buckling, wrinkling and the intermediate regions so that appropriate design rules can be used based on plate slenderness ratios. A research study was therefore conducted using experimental and numerical studies to investigate the effect of plate slenderness ratio on the ultimate strength behaviour of foam supported steel plate elements. This paper presents the details of the study and the results.

• 농촌계획
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• 제23권1호
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• pp.113-133
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• 2017

The modern agriculture has been damaged through the rapid changes due to the policy of the plundering of food during the Japanese colonial era, the Korean War, the industrialization, etc. The purpose of this research is to define the scope and the concepts of the modern agricultural heritages and to establish utilization standards of the modern agricultural heritages. With such a purpose, this research proceeds with three phases. First, the definitions the systems of the organizations the modern age and the modern agricultural heritages. Second, the analyses of the patterns and the special characteristics through the general investigation. Third, the regeneration through the comparative examinations of the case examples of the conflicts between the modern agricultural heritages. And the new attempts through the drawing of the new discussion points and the advanced tendencies are proposed. It is judged that this research will provide the point of the aim when looking at the modern agricultural heritages as the historical and cultural assets, and that it will provide the several principles when formulating the plans for the invigoration of the farm villages and the plans for the developments of the agricultural regions and provide the bases for the practical formulations.

• 한국농촌건축학회논문집
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• 제12권2호
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• pp.13-22
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• 2010

This study is to analyze women's power in family to be related to Anbang, kitchen, dining room, and utility room planning in a unit plan of condominium apartment housing in rural area Data were collected 194 unit plans from 9 eastern regions of Kungi-Do. The results are as followed: 1) Anbang reflects the women's power on changing its space character into mater bedroom, the highest hierarchy in private zone, and planning a dress room in it. 2) Dining room and kitchen is openly centered on the unit plan, but kitchen is still only women's working space for family and agriculture depended on literature review. Dining space is not activated family interaction, so it is not different from urban apartment housing. However, its location and character are changed, and its hierarchy is relatively higher with women. Dining room and kitchen tend to plan visually separated after 2001, so its trend seems to establish women's territory at home. 3) Whole family can't be easy to access utility and back balcony close to kitchen, and these spaces are functionally separated for women's house work. This design trend seems to establish for women's area. 4) Finally, women's power seems to be effective in house working area including kitchen space depended on results. Also, these results from rural condominium apartment are similar to urban ones in previous study.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1217-1226
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• 2000

Traditionally, Mobile Teletraffic model consists of two sub-models, i.e. the network traffic model and the traffic source model. In this paper, we present the traffic source model by developing MobCall (Mobile Call Simulator) which analyses various mobile wireless environments based on regional characteristics that the base stations are located. User mobility is presented by regional average vehicle speeds and the transportation share rate. Moreover, the user mobility on subway, which is increasing in urban area, is considered in MobCall. And also, user's movements on highway are considered in MobCall. The object-oriented simulation platform, C++SIM, is used to implement MobCall. Using MobCall, the accumulated number of calls in residential and commercial regions, the handoff rate with respect to traffic sources of Seoul, the handoff rate on highway, and the handoff rate according to the call duration are presented. MobCall enables the simulation of dynamic handoff buffering and functional entity control of one base station according to the changes in user's calling pattern at the design phase. Also, when a new town is under construction by a detailed plan, MobCall is used to design the mobile network with regional characteristics and user mobility considered.

• 농촌계획
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• 제19권4호
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• pp.203-212
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• 2013

The aging of farm households has caused serious problems such as productivity slowdown and aggravated income polarization in South Korea. Urban-to-rural migration has been recently suggested as a measure to attenuate the aging of rural population and other related problems. The inflow of migrants for farming can have a substantial effect on agriculture and rural communities while the natural adjustment of rural population caused by birth and death is slow. This paper forecasts population distribution of different provinces using the Origin-Destination (OD) analysis, taking into account both the size and directions of migration. In the analysis, nodes where the migration takes place are divided by the industrial sectors (agriculture and non-agriculture), regions, and ages. The results of a ten-year forecast shows that the aging of total population in most provinces will be intensified, but the portion of people over sixty will decrease in the agricultural sector. This finding implies that migration into rural areas, when occurring by a large extent, can mitigate the aging process and attendant problems.

• 한국지반신소재학회논문집
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• 제2권1호
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• pp.57-68
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• 2003

Strain-softening model is developed to characterize the interface behavior of geomembrane with geotextile and geosynthetic clay liner(GCL). The model proposed in this research is calibrated by using data from direct shear tests conducted on smooth and textured geomembrane. The research is divided into two regions, pre-peak and post-peak, to take into account of strain-softening effect. Although slight difference between measured and back calculated data is observed under high normal stress, good agreements, in general, are found from back calculations. Especially, good consistency is observed in the case of low normal stress. Based on the results, it can be concluded that the proposed model can be a reasonable constitutive law to figure out the behavior of strain-softening between interfaces of geomembrane. In addition, DSC(Disturbed State Concept) model is also presented for further application in geosynthetic interfaces.

• 수산경영론집
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• 제39권2호
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• pp.41-60
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• 2008

This study is basically to investigate the possibility of revitalizing the fishing village economy by targeting on trip type, propensity, and awareness of visitors who visited Gogunsan in JeonBuk by applying Blue Amenity. As the result of survey, it showed that visitors in Gosunsan islands generally were satisfied with trip, and they had considerably higher intention of revisit. However, it showed that the improvement and publicity of various travel services including resources and facilities were demanded. In particular, it should pay attention to requirements depending on age and selection of main visitors with reference to revisit, and as the result, the factors having the most important influence on are traffic, and natural scenery, so it is considered that these factors must be maintained to increase the rate of revisit with full of concentration. Besides, it is confirmed that Visitors are unfamiliar with Blue Amenity applying fishing village's own historical cultural resources with reference to preferring islands trip, and they were much concerned about the establishment of tentatively named "regional(urban - fishing village) center" to revitalize the fishing village economy. Moreover it could grasp the tourist industry operated jointly by fishing villages, the pride of town to characterize, advantage in promoting the tourist industry as compared with other regions, and difficulties or recommendations in promoting the tourist industry. And comprehensive investigation of Blue Amenity resources in this region and the measures of improving life environment must be performed in future.

• 한국철도학회논문집
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• 제7권4호
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• pp.412-417
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• 2004

In urban rail transit systems, ground faults in the DC traction power supply system are currently detected by the potential relay, 64P. Though it detects the fault it cannot identify the faulted region and therefore the faulted region could not be isolated properly. Therefore it could cause a power loss of the trains running on the healthy regions and the safety of the passengers in the trains could be affected adversely. Two new ground fault protective relay schemes that can identify the faulted region are presented in this paper. A current limiting device, called Device X, is newly introduced in both system, which enables large amount of ground fault current flow upon the positive line to ground fault. One type of the relaying schemes is called directional and differential ground fault protective relay which uses the current differential scheme in detecting the fault and uses the permissive signal from neighboring substation to identify the faulted region correctly. The other is called ground over current protective relay. It is similar to the ordinary over current relay but it measures the ground current at the device X not at the power feeding line, and it compares the current variation value to the ground current in Device X to identify the correct faulted line. Though both type of the relays have pros and cons and can identify the faulted region correctly, the ground over current protective relaying scheme has more advantages than the other.