• Title/Summary/Keyword: 대지

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Analysis of Electric Shock Hazards due to Touch Current According to Soil Resistivity Ratio in Two-layer Earth Model (2층 대지모델에서 대지저항률의 비율에 따른 접촉전류에 의한 감전의 위험성 분석)

  • Lee, Bok-Hee;Kim, Tae-Ki;Cho, Yong-Seung;Choi, Jong-Hyuk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.6
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    • pp.68-74
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    • 2011
  • The touch or step voltages which exist in the vicinity of a grounding electrode are closely related to the earth structure and resistivity and the ground current. The grounding design approach is required to determine the grounding electrode location where the hazardous voltages are minimized. In this paper, in order to propose a method of mitigating the electric shock hazards caused by the ground surface potential rise in the vicinity of a counterpoise, the hazards relevant to touch voltage were evaluated as a function of the soil resistivity ratio $\rho_2/\rho_1$ for several practical values of two-layer earth structures. The touch voltage and current on the ground surface just above the test electrode are calculated with CDEGS program. As a consequence, it was found that burying a grounding electrode in the soil with low resistivity is effective to reduce the electric shock hazards. In the case that the bottom layer soil where a counterpoise is buried has lower resistivity than the upper layer soil, when the upper layer soil resistivity is increased, the surface potential is slightly raised, but the current through the human body is reduced with increasing the upper layer soil resistivity because of the greater contact resistance between the earth surface and the feet. The electric shock hazard in the vicinity of grounding electrodes is closely related to soil structure and resistivity and are reduced with increasing the ration of the upper layer resistivity to the bottom layer resistivity in two-layer soil.

Characteristics of Transient Grounding Impedances of Counterpoises Relevant to the Injected Point of Impulse Currents (임펄스전류의 인가위치에 따른 매설지선의 과도접지임피던스 특성)

  • Li, Feng;Jung, Dong-Chul;Kim, Jong-Ho;Yoo, Jae-Duk;Kim, Dong-Kyu;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.5
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    • pp.62-69
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    • 2010
  • This paper presents the dependances of transient grounding impedances of counterpoises on the soil structures and the injected point of impulse currents. The transient and conventional grounding impedances of the 25 and 50[m] counterpoises buried in the soil with different resistivity were measured and analyzed as a function of the rise time of impulse currents. As a result, the transient grounding impedances give an inductive behavior, and the trend of the conventional grounding impedances is similar to that of the transient grounding impedances. The ground resistance of counterpoises is irrespective to the injected of impulse current, but the transient and conventional grounding impedances in a short time range especially depend on the soil resistivity and position of the injected point of impulse currents.

Analysis and signal stability measurement for DGPS radio wave propagation (DGPS 전파 신호의 안정도 측정 및 분석)

  • Kim, Young-wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.2
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    • pp.231-236
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    • 2016
  • The stability of DGPS signal in the DGPS service area was measured and the service availability according to the receiving signal strength was analyzed in this paper. Based on the effects of radio wave propagation in the seasons of winter and summer, daytime and night, the method to provide the DGPS service coverage was presented in this paper. The signal's strength of DGPS radio wave were measured at a constant distance from the DGPS reference station during a constant period. The propagation of DGPS radio wave is affected by status of ground conductivity, so the DGPS service area is dependant on the ground conductivity. To provide the stable service coverage, it is necessary to apply the adaptive power control for receiving signal's variations and the antenna design for alleviation of high elevation's radiation.

Analysis and measurement of service area of ocean-based DGPS reference station in Korea (국내 해상 DGPS 기준국의 서비스 영역 측정 및 분석)

  • Kim, Young-Wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1255-1261
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    • 2014
  • Based on the radio wave measurement of korean ocean-based DGPS by season, in this paper, the service coverages of ocean-based DGPS reference stations were analyzed according to the climate and season. The signal strengths and signal-to-noise ratios in the land service areas that are provided by ocean-based DGPS reference stations were measured. The ocean-based DGPS reference station except reference stations on the mountainous terrain and the low ground conductivity provide more than 68% service area in comparison with the designed land service coverage providing by the ocean-based DGPS reference stations. To provide the designed service area that is unrelated to a season, it is necessary to install and operate the DGPS reference station with good ground conductivity and high efficiency antenna. Also, the poor service regions which is generated by obstacles of electric wave on pathway can be resolved by the double service area providing by land-based DGPS reference stations.

An Analysis of Complex for a Parking Lot Expansion (주차장 확대를 위한 공동주택 단지특성 분석)

  • Ha, Na;Song, Nak-Hyun;Yoon, Ho-Bin;Lee, Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.1039-1042
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    • 2007
  • The number of vehicle has been increased due to growth of economy. Consequently, the needs for parking area has been increasing. there is a serious problem in aged-apartments. It result from observing a parking lot law at that times. That is the reason why residents demand parking lot expansion. Parking lot addition is being studied on a lots different standpoint to solve the present parking lot condition. Parking lot expansion is limited by housing complex characteristics. This study analyzed the housing complex characteristics of aged-apartment. It is analyzed that the number of house holders, distance between buildings, and level of site for finding housing complex characteristics. The result are as follows. the complex lower than 300 households is about 35% in the Number of households. The buildings which has a moving distance from 41m to 50 is nearly 23%. Them the 멕스둣 house located on the flat is 82%. This study will become a reference data for the parking lot expansion.

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Frank Lloyd Wright's Houses in relation to the Earth and the Sky (라이트의 주택에 나타난 대지와 하늘의 인식에 관한 연구)

  • Kim, Tai Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.18 no.3
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    • pp.1-8
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    • 2016
  • Frank Lloyd Wright(1867-1959) had the confident concept that architecture should be at home in nature. His architecture was meant to bear an intimate relation to the earth and the sky, and should look as though it began there at the ground and contrasted with the sky. In handling all the details of house design elements, his efforts for being married to the ground was to conceive the void of the sky. This study is to research his thinking process and its development to the earth and the sky, and to analyze how such thought could reflect his houses. The mass of house are divided into three parts such as the foundation or base, body, and roof. These parts are respectively related to the earth and the sky. This study goes on regarding them as an analytical framework. The subjects of study are the Prairie houses in the early 20th century and the Usonian houses after 1930's. As results of this study, the earlier foundation as a platform appeared as a base and water table, and a strong baseline pressed the structures into the soil in the Prairie houses. The direct contact of wood and brick to ground were dominant details after Wiley house(1934). The base was almost invisible to the eye in the Usonian houses. Secondly, the pierlike shapes and delicate friezes of walls were anchored to the ground, and horizontal bands as trims or copings also got close to the earth. These characters had disappeared after the Allen house(1917), all components including exterior walls had been unified with the grid patterns in the Usonian houses. Thirdly, the overhanging cantilever roof had got to the earthbound by the reflection of shadow as well as their evident horizontal. He lowered the roof, lengthened and brought it closer to the ground. In this way, Frank Lloyd Wright intended his houses to be at home in nature. And also he tried to bind the houses to the earth and contrasted them with the sky. The houses would perform their highest function in relation to the earth and sky.

A Study on the Place Name of Migration in Three Northeast Provinces of China I : Case of the Yanbian Korean Autonomous Prefecture (중국 동북 3성의 이식지명에 관한 연구 I - 연변 조선족 자치주를 사례로 -)

  • Kim, Nam-Sin;Jin, Shizhu
    • Journal of the Korean association of regional geographers
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    • v.20 no.2
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    • pp.153-162
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    • 2014
  • This Research is to study types and distribution for place name of migration derived from Korea Peninsula by analyzing villages name of the Yanbian Korean Autonomous Prefecture. Village names of Yanbian Korean were identified as 945 out of 2,015. Place name migrated from Korea Peninsula was turned out 51 villages. Up to the present time in the Transition of China, 34 place names were disappeared, maintained place names were 16, and rehabilitated place name after loss was 1. The place name by naming method were classified as small area directed migration, large area directed migration, and merged migration. In case of small area directed migration, origin and destination is same such as Jeongeup and Muju, Cheonbuk, large area directed migration is named case by region migrants like a Gangwonchon named by people moved from GanwonDo, and merged case combine initials with each village names in case of GilseongChon by colligated Gilju and Seokseongmyeon. The results will be expected to support research information for identity and ethnical migration process.

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Stratigraphic Analysis on Paleofluvial Outcrop underJeongok Basalt Layer in the Chugaryeong Rift Valley, Central Korea (추가령 열곡 내 전곡 현무암층 하부 고하성층 노두 층서 분석)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.3
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    • pp.55-63
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    • 2013
  • The study deals with the geochemical analyses on the stratigraphy and sedimentation of the paleofluvial outcrop under Jeongok basalt layer in Chugaryeong Rift Valley. The results of field survey and analysis show that the paleofluvial sand and gravel layers had been constructed before the arrival of basaltic lava in Jeongok area of Hantan River valley in central Korea. XRF, for the main elements analysis, results present that JG2-3, a test sample from basalt weathering layer, has different characteristics from 5 other samples in the aspects of chemical weathering levels. ICP-MS, for analysis of the rare earth elements analysis, estimates that gravel layer, in the lowest part of the outcrop, had been originated from pre-lava bedrocks near the upper reach of the Hantan River, so the layer is almost not related to basalt layers. Finally, the OSL dating results in paleofluvial sedimentation had been in process until nearly 40,000 BP, before formation of lava plateau in the Jeongok area.

Discrimination of Volcanic Ash and Asian Dust (Hwangsa) in Core Sediments from the South Korea Plateau (East Sea) Using Characteristics of Grain-size Distributions (입도 분포 특성을 이용한 동해 남한국대지 시추 퇴적물 중 화산재와 황사의 구분)

  • LEE, HONG-WON;JANG, JUN-HO;BAHK, JANG-JUN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.2
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    • pp.135-144
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    • 2021
  • End-member (EM) analysis of grain-size distribution data for detrital fractions of IODP Site U1430 core sediments from the South Korea Plateau (East Sea) identified 4 EMs grain-size populations (EM) which represent either Asian dusts (Hwangsa) or volcanic ashes. The two EMs representing volcanic ashes consist of fine and coarse glass shards with various morphologies and constitute 0-82% of the total grain-size distributions. The 33% mixing percentage of volcanic ash EMs seems appropriate for a cut-off value for discrimination of grain-size data influenced by volcanic ash input from those dominated by Hwangsa.

Urban Tissue, Zoning and Achieved Floor Area Ratio (A-FAR) - Focused on Developed Floor Area Ratio (D-FAR) Compared to the Legal Floor Area Ratio (L-FAR) in Residential Area and Commercial Area in Seoul - (용적실현비(A-FAR)에 영향을 미치는 용도지역별 대지특성에 대한 분석 - 서울시 주거지역 및 상업지역에서 법정용적률(L-FAR) 대비 실현된 용적률(D-FAR)을 중심으로 -)

  • Kim, Soo Hyun;Choi, Chang Gyu
    • Journal of Korea Planning Association
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    • v.54 no.2
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    • pp.33-45
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    • 2019
  • The Legal Floor Area Ratio (L-FAR) has been used as a major urban planning tool for efficient management of land use, landscape, and density. The Developed Floor Area Ratio (D-FAR) in each parcel is realized by such physical and institutional factors as urban tissue, local characteristics, and zoning with the L-FAR. The Achieved Floor Area Ratio (A-FAR), the ratio of the D-FAR to the L-FAR, is the relationship between realized density and the intended/desired outcomes of the regulations. The A-FAR informs the efficiency of L-FAR and its effect on parcels, and is an indicator of the demands of real estate developments under the zoning regulation. This study used detailed data of each parcel's characteristics, including parcel size, road width, and the number of roads bordered by a parcel, to identify the influencing factors on A-FAR. This analysis confirmed that the parcel size has a non-linear negative effect in the residential zone but a linear positive effect on A-FAR in the commercial zone. The width of the parcel's frontage in the commercial zone has a positive effect on the value, while in the residential zone the narrower width has higher A-FAR. In Seoul, the residential zone has higher A-FAR than the commercial zone, which means that the former has a relatively higher development pressure but a lower designated L-FAR. This result reflects that Seoul's residential zone absorbs the demand of commercial uses because of the significant permitting of mixed land use and has high-density residential buildings.