• 제목/요약/키워드: Low area

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ICS 극소출력 중계기를 이용한 난시청 개선 (Improvement of Fringe Area using ICS Extremely Low Power Repeater)

  • 최수철;조기량
    • 방송공학회논문지
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    • 제21권1호
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    • pp.97-104
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    • 2016
  • 본 논문에서는 지상파 Digital TV(Television) 방송의 난시청 지역 해소를 위하여 동일 채널 DTV ICS(Interference Cancellation System) 극소출력 중계기를 이용한 필드 테스트 분석을 통한 효과를 입증하였다. 전국적으로 산재한 난시청 지역(자연적) 및 건물(인위적)중에서 7개소를 필드 테스트 지역으로 선정하고, 각 방송국(KBS1, KBS2, EBS, MBC, SBS)에 대하여 ICS 극소출력 중계기의 설치 전, 후의 수신 전계 강도와 SNR(Signal to Noise Ratios)을 측정하고, 또한 수신율 개선 현황을 통하여 ICS 극소출력 중계기의 효과를 검증하고, 향후 ICS 타입 극소출력 중계기의 확산을 위한 연구 기반을 제공하였다.

TCSC의 $H_{\infty}$ 제어에 의한 대규모 전력계통의 지역간 저주파진동 억제 Part II: $H_{\infty}$제어기 설계 (Damping Inter-area Low Frequency Oscillations in Large Power Systems with $H_{\infty}$ Control of TCSC PARTII: Design of $H_{\infty}$ Controller)

  • 김용구;전영환;송성근;심관식;남해곤
    • 대한전기학회논문지:전력기술부문A
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    • 제49권5호
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    • pp.233-241
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    • 2000
  • This paper presents a systematic design procedure of $H_{\infty}$ controller of TCSC for damping low frequency inter-area oscillations in large power systems. Sensitivities of the inter-area mode for changes in line susceptance are computed using the eigen-sensitivity theory of augmented system matrix and TCSC locations are selected using the line sensitivities. The reduced model required for designing a manageable-size $H_{\infty}$ controller is obtained using the reduced frequency domain system identification method and the various weighting functions are tuned systematically to provide a robust performance. The proposed $H_{\infty}$ controller proved to be very effective for damping the inter-area mode of the large KEPCO power system.

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농촌의 혼인 관련 인구학적 현황과 농촌미혼남성의 혼인과 국제결혼 관련 태도분석 (An Analysis of the Demographic Characteristics & the Attitude about International Marriage of Unmarried Farmers in the Rural Area of Korea)

  • 정현숙;양순미
    • 가정과삶의질연구
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    • 제27권1호
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    • pp.17-29
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    • 2009
  • The aim of this paper is to examine the demographic characteristics and the attitude about marriage and the policy of the unmarried male farmers. The contents of research are two folds: 1) Analyze the marriage related demographic statistics of rural area using the data from Korea Statistical Information System and marriage statistics in 2007, 2) survey analyses of the attitude toward marriage, perception and needs of international marriage, and related policies from data of 170 unmarried male farmers. The results are as follows: first, the marriage rates among over 15 years old of the rural area is 78.2% for men while 1.8% for 20${\sim}$24 age group and 9.3% for 25${\sim}$29 age group. The marriage rates in this area are varied by region especially low in Kyunggido & Jejudo. Second, the portion of international marriages of Korean male farmers with foreign partner are 11% among all international marriages of Korean males. There are high rates of male farmers' international marriage in Junranamdo and Kyungsangbukdo which are characterized by low level of urbanization, low inter-city mobility, low rates of age group of under 15 years and high portion of over age 65. Finally, the survey results showed that 83% of the sample lived with their parents; event though 80% of farmers think marriage is necessary, 60% had no plan of marriage because of difficulties to meet marriage partners and of lacking economic resources; they showed a negative perception toward the handicapped, foreigners, Afro-Americans, Westerners and divorcees as a marriage partner; they also showed negative recognition to international marriage because of observed problems of neighboring international marriage couples and concerns of cultural differences; they pointed out that the government's concern about improving quality of the environment of the rural area and reforming the international marriage aid law was the most necessary. The discussion and the future research directions were added.

농어촌 지역병원 의료이용률 제고방안 (A Methodology for The Improvement of Rural Hospital's Utilization)

  • 안인환;문영전
    • 한국병원경영학회지
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    • 제12권4호
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    • pp.119-142
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    • 2007
  • Although Korea joined OECD in 1996, there has still seen much unbalance in medical care and welfare standard between urban and rural area. The unbalance of medical demand between urban and rural area deepened low utilization of rural hospitals. So it caused many hospital's failure and conversion in rural area. Many rural hospitals are in difficulty managing business because of low medical demand along with the shortage of medical manpower, medical equipment and facilities. The objectives of this study were to reveal the cause of low utilization of hospitals in rural area, and to increase utilization of those hospitals. In this study the improvement methods of rural hospital's utilization were presented by examining were placed in difficult management condition, in respect of hospital's management conditions, manpower input, patient medical treatment record, financial record, and actual output. The causes of rural hospital's low utilization were as follows; 1) changes in number and structure of population 2) rural people's preference for large hospitals and hospitals which located in urban area 3) rural hospitals lacking in hospital management skill. Consequently rural hospital's operation condition got more and more deteriorated. To raise rural hospital's utilization, method for social policy, method for health policy, and intrinsic method of hospitals were presented in turn. For rural residents to utilize medical service conveniently, it is necessary for rural hospitals operated normally. So government must insist that rural hospitals solve the problems which come out from their internal management problems. And also these rural hospitals should be supported and nurtured by the government until their management is operated normally.

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백삼산지에서 작황과 수량과의 관계 (Relation between Crop Stand and Yield in White Ginseng Cultivation Area.)

  • 박훈;이명구;변정수;이종율
    • 한국작물학회지
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    • 제32권3호
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    • pp.369-374
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    • 1987
  • 풍기와 금산지방의 백삼포장을 대상으로 인삼의수량, 재식본수, 결주율, 근중엽면적 수확근수간의 상호관계를 조사하였다. 1. 금산지방은 풍기지역보다 재식본수가 거의 2배나 되며 박엽을 및 결주율이 높고 수량은 낮았다 2. 수량이 밀식재배에서는 근수에 의존하고 소식재배에서는 근중에 의존하였다. 결주율이 수량에 주는 영향은 밀식재배에서 더욱 현저하였으며 재식본수는 유의성은 없으나 수량과 부상관이였다. 결주율과 재식본수와는 무관하였다. 3. 채굴본수는 재식본수에 의존하고 특히 결주율에 의해 제한되었다. 4. 수량은 수확기 엽면적지수(LAI) 특히 생육 최성기 LAI 에 의존하였으며 LAI는 밀식재배에서는 채를 본수에만 소식재배에서는 주엽면적에만 의존하였고 LAI 는 밀식과 소식재배간 차이가 없었으며 MR에 의하여 제한되었다. 5. 주엽면적은 근중에 고도로 의존하였으며 밀식에 의하여 LAI 가 증대하지 않는 원인이고 모든 포장은 최적 LAI 이하였다.

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국내 미계측유역의 갈수량 산정 개선 (Improving Low Flow Estimation for Ungauged Basins in Korea)

  • 조탁근;이길성;김영오
    • 한국수자원학회논문집
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    • 제40권2호
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    • pp.113-124
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    • 2007
  • 갈수량(low flow)은 과거 자연상태 하천에서 갈수기에 흘렀던 유량으로서 자연과 사람이 공유할 수 있는 최소한의 유량이며, 이수측면에서 하천수의 공급능력을 평가하여 취수량을 설정하는 기준 유량이다. 일본과 우리나라에서는 평균갈수량과 기준갈수량을, 미국과 영국 등에서는 10년빈도 7일 갈수량($7Q_{10}$)을 갈수량 지표로 사용하고 있다. 본 연구에서는 위의 세 지표를 관측자료와 모의 생성자료를 이용하여 비교하고 고찰하여 보았다. 갈수량 산정을 위해서는 과거의 관측 유량자료가 필요하나 국내에는 수위관측시설이 한정되어 있을 뿐 아니라 홍수기에 비해 갈수기 자료가 턱없이 부족하여 갈수량 산정에 많은 어려움을 겪고 있다. 국내에서는 대부분 비유량법(drainage-area ratio method)으로 미계측유역의 갈수량을 산정하고 있다 본 연구에서는 미계측유역(ungauged basin)의 갈수량을 산정하기 위한 방법으로 비유량법과 지역회귀기법(regional regression method), 기저유량상관법(baseflow correlation method)을 국내에 적용하여 보고, 각 방법의 적용시 지침과 국내에 적합한 갈수량 산정방법을 제시하였다.

금산의 서로 다른 3 토양내에 생육되는 인삼의 전이원소 함량 특성 (Characteristics of the transitional element contents for the ginsengs from the 3 different soils of Keumsan)

  • 송석환;민일식;박관수;유선균
    • Journal of Ginseng Research
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    • 제29권4호
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    • pp.192-205
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    • 2005
  • This study is for geochemical relationships between ginsengs and soils from three representative soil types from Keumsan, shale, phyllite and granite areas. For this study, ginsengs (2, 3 and 4 years), with the soils and their host rock, are collected and are analysed for the transitional elements. In the weathered soils, the shale area is high in the most of elements, but low in the granite area. High correlation relationships are shown in the shale area. In the field soils, the shale area is mainly high, but low in the granite area. Comparing with ages, most of elements are high in the 2 year soils, but low in the 4 year soils. Regardless of the localities, positive and negative correlations are dominant in the shale area. In the host rocks, high element contents are shown in the phyllite and shale areas. Positive and negative correlations are found in the shale and phyllite areas for large numbers of the element pairs. In the ginsengs, differences of the element contents with ages are not clear, but show high element contents in the 2 year ginsengs of the shale and phyllite areas, and low contents in the 4 year ginsengs of the granite area. Positive correlations are shown in the Cu-Zn pair in the shale and phyllite areas, and Co-Cu pair in the granite area. In the relative ratios(weathered soil/field soil), most of elements from the shale area are high, above I, suggesting high element contents in the weathered soils of the shale area relative to the granite and phyllite areas. In the relative ratios(weathered soil/host rock), most of elements are above 1, suggesting the high element contents in the weathered soils relative to the host rocks. Relative ratios (soil/ginseng) of the element contents are several to ten times. Regardless of the areas, big differences of the relative ratios are found in the Co and small differences are in the Cu and Zn, which suggest that differences between soils and ginsengs are big in the Co contents and small in the Cu and Zn contents. Regardless of the ages, differences among relative ratios are small in granite area relative to the shale area, which suggest more similar contents between ginsengs and soils in the granite areas.

저소득층 아동의 주거환경 (Home and Neighborhood Environment of Children: Based on Socio-economic Status and Settlement Character)

  • 곽은순;정미라
    • 한국지역사회생활과학회지
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    • 제18권3호
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    • pp.493-505
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    • 2007
  • The purpose of this study is to examine the regional differences of 0-12 aged children's environment based on their parents' socioeconomic class and on the character of the settlement. One thousand and two hundred households were investigated and the results are as follows. It is revealed that families in low socio-economic class are more likely to be exposed to noise and home crowdedness. Families living in spontaneous settlement are deprived of natural light and the roads to their homes are steep and narrow. Low income families face a housing affordability crisis. Most of them pay housing rent on monthly basis. The basic infrastructure of low income neighborhood is lacking convenient facilities like shopping centers, public transportation systems, banks, public parks, and libraries. This lack of facilities is more severe in spontaneous settlement. Instead, bars and taverns are located in their neighborhood. Accessibility to parks and resource centers is an important factor that makes both middle and low income families consider their neighborhood to be positive and this condition is counted better in social housing area than in spontaneous settlement. On the contrary, social networks like friends and relatives are strong in spontaneous settlement and families in poverty value these relationships. Such networks are weak in social housing area and this difference is not related to their residential period. Low income families living in social housing area are more pessimistic about their future and this view might result from their counterpart middle class neighbors and the weak social networks.

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유치거리 분석을 통한 도시공원의 적정배치에 관한 연구 (Proper Arrangement of City Park though Analysis of Disposition Distance)

  • 류연수;나정화;도후조
    • Current Research on Agriculture and Life Sciences
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    • 제20권
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    • pp.33-38
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    • 2002
  • The purpose of this study is to analysis of disposition distance of city park for the plan of suitable arrangement of city park based on the date examining Daegu Metropolitan City. The results of this study are as follows. 1) The result of analysis of population density as the case of districts, it appeared highly in city center area which Seo-Gu district and Nam-Gu district besides Jung-Gu district. However, it apperared in a low Buk-Gu district, Dong-Gu district and Salseong-Gun. 2) The result of analysis of population density as the case of regions, it appeared very highly Joukjun-Dong of Dalseo-Gu district($31,554per/km^2$), Naedang-Dong of Seo-Gu district($29,922per/km^2$). However it appeared in a low Yeuga-Maen($85per/km^2$) and Gachang-Maen($94per/km^2$) of Dalseong-Gun. The regions where the population density is high have very low green space and live a lot of low income layer. 3) The result of analysis of disposition distance, in the case of children park, it appeared an intensive distribution in Dongcheon-Dong and Guam-Dong of Buk-Gu district, Whanggm-Dong and Dusan-Dong of Suseong-Gu district, Sangin-Dong and Yeongsan-Dong and Walsung-Dong of Dalseo-Gu district. however, it appeared in a low in Jung-Gu district. The case of urban park of the neighboring area, it appeared the most in Dalseo-Gu district except 2 parks in Jung-Gu district, the case of urban park of the walking area, it appeared in equality in city. 4) In conclusion, the area have high population density and lots of low income layer, is in out of disposition distance should be considered in first for city park plan.

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부산지역 오존농도의 주말 효과 특성 (Characteristics of Ozone Concentration Weekend Effect in Busan Area)

  • 전병일
    • 한국환경과학회지
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    • 제23권5호
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    • pp.861-871
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    • 2014
  • This study analyzes the characteristics of ozone weekend effect(OWE) in Busan. $O_3$ concentration on Sunday was over 10% higher than that on weekdays in all areas except for Kwangbokdong, Taejongdae, and Joadong. Such a difference was higher in the industrial area than in the residential area. $O_3$ generation was facilitated by the decrease in $NO_X$ emission on Sunday in VOC-limited regime where the VOC/$NO_X$ ratio is low. Low NO concentration in the Sunday morning decreased inhibition of $O_3$. NO-$O_3$ crossover time on Sunday was shorter than that on weekdays which in turn extended the accumulated duration of $O_3$. Future studies can include whether the entire Busan is VOCS-limited or the coastal area is VOCS-limited while the inland area is $NO_X$-limited.