• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.346-352
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• 2009

The eventual goal of this paper is to help the generating companies and load-serving entities to choose appropriate relative levels of interconnected system versus bilateral trades while considering risk, and economic performance. In competitive power markets, electricity prices are determined by balance between demand and supply in electric power exchanges or bilateral contracts. The problem formulation is bilateral contract incorporated into Multi-area unit commitment with import/export and tie-line constraints. This proposed method considers maximizing own profit or minimize the operating cost among the generating companies in multi-area system. The feasibility of the proposed algorithm has been demonstrated using IEEE system with four areas and experimental results shows that proposed method is reliable, fast and computationally efficient

• 한국주거학회논문집
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• 제21권1호
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• pp.53-65
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• 2010

Apartment buildings represent the most typical patterns of housing in Korea. The present plans are very different from the previous ones when they appeared for the first time. Although apartment unit plans has changed drastically, they can be classified into several categories. Apartment unit plans reflects the demands of living activities and space dimensions of unit plans have the characteristics of diachronic continuity and carry the values of living culture. Thus this study aims to provide the statistical dimensional data of each room that can be actually used for the design of unit plans by sub-grouping typical unit plans. The statistical data of this study showed that apartment unit plans are shifting from 2bay/3room type to 3bay/3room type in 1990s. It is very peculiar that the typical unit plan of $60\;m^2$ area becomes to resemble that of $85\;m^2$ area. The space arrangement of typical unit plans of both $60\;m^2$ and $85\;m^2$ area is almost identical while only their space dimensions differ slightly. As the mean/mode/median values of space dimensions in a typical unit plan are converging into a range of narrow margin, space dimensions of typical unit plan are contended to be strictly regular. The statistical numeric data of various space dimensions provided in this paper can be applied practically to the design of apartment unit plans for low income class people who are disprivileged in the society.

• 한국농공학회지
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• 제29권4호
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• pp.59-72
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• 1987

Although long-term runoff analysis is important as much as flood analysis in the design of water works, the technological level of the former is relatively lower than that of the latter. In this respect, the precise estimation model for the volume of successive runoff should he developed as soon as possible. Up to now, in Korea, Gajiyama's formula has been widely used in long-term runoff analysis, which has many problems in applying in real situation. On the other hand, in flood analysis, unit hydrograph method has been exclusively used. Therefore, this study aims at trying to apply unit hydrograph method in long-term runoff analysis for the betterment of its estimation. Four test catchment areas were selected ; Maesan area in Namlum river as a representative area of Han river system, Cheongju area in Musim river as one of Geum river system, Hwasun area in Hwasun river as one of Yongsan river system, and Supyung area in Geum river as one of Nakdong river system. In the analysis of unit hydrograph, seperation of effective rainfall was carried out firstly. Considering that effective rainfall and moisture condition of catchrnent area are inside and outside of a phenomenon respectively and the latter is not considered in the analysis, Initial base flow(qb)was selected as an index of moisture condition. At the same time, basic equation(Eq.7) was established, in which qb can take a role as a parameter in relating between cumulative rainfall(P) and cumulative loss of rainfall(Ld). Based on the above equation, computer program for estimation model of qbwas seperately developed according to the range of qb, Developed model was applied to measured hydrographs and hyetographs for total 10 years in 4 test areas and effective rainfall was estimated. Estimation precision of model was checked as shown in Tab- 6 and Fig.8. In the next stage, based on the estimated effective rainfall(R) and runoff(Qd), a runoff distribution ratio was calculated for each teat area using by computerised least square method and used in making unit hydrographs in each test area. Significance of induced hydrographs was tested by checking the relative errors between estimated and measured runoff volume(Tab-9, 10). According to the results, runoff estimation error by unit hydrograph itself was merely 2 or 3 %, but other 2 or 3 % of error proved to be transferred error in the seperation of effective rainfall. In this study, special attentioning point is that, in spite of different river systems and forest conditions of test areas, standardized unit hydrographs for them have very similar curve shape, which can be explained by having similar catchinent characteristics such as stream length, catchinent area, slope, and vegetation intensity. That fact should be treated as important factor ingeneralization of unit hydrograph method.

• 한국초등수학교육학회지
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• 제13권1호
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• pp.115-140
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• 2009

Freudenthal은 수학화를 핵심 개념으로 하는 현실주의 수학 교육론을 주창하였다. 수학화란 현실 안에 있는 여러 현상들을 수학적인 수단을 사용하여 조직함으로써 현실에 질서를 부여하는 활동을 말한다. 본 연구에서는 Freudenthal의 수학화 이론을 바탕으로 제 7차 초등 수학 교과서 5-가 단계의 넓이 단원을 재구성하여 실험적인 지도만을 작성한 다음, 이를 통하여 교수 실험을 실시함으로써, 수학화를 통한 넓이의 지도 방안의 효과와 더불어 학생들의 넓이 개념과 공식에 대한 이해 실태를 분석하였다. 그 결과, 넓이의 개념 이해 측면에서는 실험반 학생들이 우수하였으나, 넓이의 계산 측면에서는 유의미한 차이가 없는 것으로 나타났다.

• 한국주거학회논문집
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• 제23권4호
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• pp.41-48
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• 2012

The purpose of the study, approaching from the aspect of the construction technologies, is to determine the architectural techniques of traditional wood architects in existence, through which the systems and techniques that create the inherent characteristics of Korean Architecture are clarified. With understanding traditional construction system and focusing on the fact that built environment results from the consistent standards and technologies of architects, this study inquires into the systematic standard and its formation that present in the process of planning for the overall scale and shape of a building from the following (four) perspectives. The study determines the characteristics of '間(Kan)' (unit; fundamental unit that measures Korean traditional houses) and the methods of columns disposition of which the '間 (Kan)' is made up. Once the necessary spaces are decided according to the size of a building, then floor plans are drawn with the standard unit, '間(Kan)'. The '間(Kan)', as a modular unit, is not only composing the floor plans, but also functioning as an Area unit, Space unit and Structural unit. Composition of '間(Kan)' varies with disposition of columns, and therefore multiform of floor and spaces are created. In this study, the '間(Kan)', as a standard unit, is used in the form of specific size and area, and it is demonstrated how the floor plans are developed by organizing the columns in accordance with the spaces requested.

• 농업과학연구
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• 제43권4호
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• pp.603-611
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• 2016

The aim of this study was to analyze the contribution factors (backfat thickness, eye muscle area, carcass weight, marbling score, and feeding period) affecting meat unit price (South-Korean Won / Kg of meat). The best slaughtering age to maximize unit price was also assumed. All data used in this study were acquired from the Korea Institute for Animal Products Quality Evaluation from 2010 to 2014. Contributions to the estimated unit price of cows by the following factors, backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score were 2.65%, 0.04%, 1.58%, 1.58%, and 95.72%, respectively. Contribution to estimated unit price of steers by the same factors (backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score) were 7.88%, 1.24%, 0.07%, 90.81%, and 95.72%, respectively. Slaughtering ages ranged from 26 to 36 months and the data were separated into each month for an 11 month period. The unit price of meat from Hanwoo slaughtered at 30 months was highest among groups. The lowest unit price was observed in the group belonging to the Hanwoo slaughtered at 36 months. In conclusion, of all contributing factors, marbling score affected unit price the most. Based on our results, it is recommended that the optimal slaughtering age be set at 30 months to maximize unit price. Moreover, the feeding of beef cattle past 30 months of age is not recommended because of the increase in feeding costs.

• 안보군사학연구
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• 통권13호
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• pp.137-658
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• 2016

1. Movement of the leaders of the Silla army The leaders of the Silla army traveled from Gyeongju(경주) to Icheon (이천), Deokjeokdo(덕적도) Island, and Hwangsanwon(황산원) during the period of the Against Baekje(백제) War that began in 660. Movement route between Gyeongju and Icheon : Gyeongju(경주)-Daegu(대구)-Gumi(구미)-Gimcheon(김천)-Chupungryeong(추풍령)-Geumdol Fortress(금돌성)-Boeun(보은)-Jincheon(진천)-Juksan(죽산)-Bubal-eup(부발읍) Movement route between Bubal-eup and Deokjeokdo Island : Bubal-eup(부발읍)-Ipo(이포) Ferry-Haengju(행주) Ferry-Palmido (팔미도) Island-Seonjaedo(선재도) Island-Yeongheungdo(영흥도) Island-Pido(피도) Island-Soyado(소야도) Island-Deokjeokdo(덕적도) Island Movement route between Deokjeokdo Island and Hwangsan: Deokjeokdo(덕적도) Island-Danghangpo(당항포)-Jincheon(진천)-Boeun (보은)-Okcheon(옥천)-Geumsan(금산)-Tanhyeon(탄현)-Hwangsan (황산)-Ganggyeong(강경)-Buyeo(부여) 2. Movement of the combat units of the Silla army Jincheon area : 4,325 persons of the Geupdang unit(急幢) and 611 persons of the Kaegeumdang unit(罽衿幢) were deployed. These units moved from Jincheon to Cheongju, Yeongi, and Gongju, and contained Ungjin Fortress(熊津城) (6,650 Baekje troops). Boeun area : 4,763 persons of the Daedang(大唐) unit, 3,548 persons of the Hajujeong unit(下州停), 3,017 persons of the Namcheonjeong unit(南川停), and 4,500 persons of the Saseoldang unit(四設幢) were deployed. These units moved from Boeun(보은) to Okcheon(옥천), Geumsan(금산), Tanhyeon,(탄현) and Hwangsan(황산). Geumdol Fortress area : 3,753 persons of the Sangjujeong unit(上州停), 5,762 persons of the Seodang unit(誓幢), 3,753 persons of the Guidang unit(貴幢), and 5,562 persons of the Nangdang uni(郎幢)t were deployed. These units moved from Geumdol Fortress to Hwanggan(황간), Yeongdong(영동), Geumsan(금산), Tanhyeon(탄현), and Hwangsan(황산). Jirye area: 3,017 persons of the Eumrihwajeong unit(音里火停) and 3,017 persons of the Ehwahyejeong unit(伊火兮停) were deployed. These units moved from Jirye(지례) to Juchiryeong(走峙嶺), Mupung (무풍), Muju-eup(무주읍), and Bunam-myeon(부남면) in Muju-gun. Goryeong area: 3,017 persons of the Samryanghwajeong unit(三良火停) and 3,017 persons of the Sosamjeong unit(召參停) were deployed. These units moved from Goryeong(고령) to Geochang(거창), Hamyang(함양), Namwon(남원), Sunchang(순창), and Jeongeup(정읍). 3. Movement of the Tang army Dangjin area(당진 방면) : 1,000 persons were deployed. These units moved from Dangjin(당진) to Myeoncheon(면천), Yesan(예산), and Imjon Fortress(임존성). Garijeo area(가리저 방면) : 1,000 persons were deployed in the Garijeo(加里渚) area. These units moved from Garijeo(가리저) to Myeoncheon(면천), Yesan(예산), and Imjon Fortress(임존성). Geumganggu area(금강구 방면) : 000 persons were deployed. These units moved from Geumganggu(금강구) to Ganggyeong(강경) and Sabi Fortress(사비성). 4. Baekje military deployment Total troops of the Baekje army : There were 60 thousand Baekje troops according to the Old Book of Tang(舊唐書). Troop deployment by the Baekje army: 62,230 persons were deployed in 15 regions: 1,000 in Dangjin(당진), 1,000 in Garijeo(가리저), 6,120 in Imjon Fortress(임존성), 1,120 in Namjam Fortress(남잠성), 1,350 in Dooryangyun Fortress(두량윤성), 870 in Wangheungsajam Fortress(왕흥사잠성), 6,650 in Ungjin Fortress(웅진성), 1,120 in Jinhyeon Fortress(진현성), 1,000 in Dooshiwonak(두시원악), 1,000 in Irye Fortress(이례성), 5,000 in Gosaburi Fortress(고사부리성), 5,000 in Gujiha Fortress(구지하성), 3,000 plus 3,000 in Gibeolpo and Yangan(기벌포 양안), 5,000 in Deukan Fortress(득안성), and 20,000 in Sabi Fortress(사비성).

• 한국물환경학회지
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• 제30권2호
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• pp.128-137
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• 2014

The land use of the unit watersheds should be maintained appropriately in order to keep the load allotment stable for the management of Total Maximum Daily Loads (TMDLs). This study classified the land area in four types and analyzed the use of each land type and its changing pattern by calculating the occupation and conversion ratios for the unit watersheds in three river basins. The forest land showed the greatest occupation ratio with 63.0%, followed by the farm land with 23%, the other area with 8.0% and the site area with 6.0% in 2003. The occupation ratio of the site and the other area increased by 0.4% and 0.2% respectively, and that of the farm and the forest land decreased by 0.4% and 0.2% respectively in 2007. The conversion ratio for the site area ranged from 1.65% to 1.97%, for the farm land from -0.47% to -0.33%, for the forest land from -0.10% to -0.04% and for the other area from 0.17% to 1.97%. It can be inferred that the decrease in the farm and the forest land contributed to the increase in the site area and that the increase in the other area was mainly made by the decrease in the forest land. It could be more effective to take into account the changes in the site area and in the forest land in the process of developing the TMDL plans.

• 한국환경복원기술학회지
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• 제16권5호
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• pp.71-81
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• 2013

This study is aimed to provide basic data for the estimation of carbon effects in development project areas such as Happy Housing Project which includes redevelopment and reconstruction projects by inducing the basic unit of carbon effects and strategic planning and management to enhance carbon effects. According to the analysis, in urban parks, carbon uptake and carbon storage by the unit area of living area parks were $7.614kg/m^2$ and $18.5203kg/m^2$ respectively while carbon uptake and carbon storage by the unit area of theme parks were $1.2261kg/m^2$ and $2.831kg/m^2$ each. In facility greens, carbon uptake and carbon storage were $0.5683kg/m^2$ and $0.6636kg/m^2$ respectively while they were $10.77kg/m^2$ and $13.69kg/m^2$ individually in other urban planning facilities. In other greens, on the contrary, carbon uptake and carbon storage were $0.45kg/m^2$ and $1.02kg/m^2$ respectively. In site landscape, carbon uptake and carbon storage by the unit area of apartment landscape were $3.7394kg/m^2$ and $9.2292kg/m^2$ each.

• KIEAE Journal
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• 제10권5호
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• pp.43-55
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• 2010

This research investigated 162 residential unit plans which were located in Seoul and Gyonggi Province ranging from 58 to $118m^2$ unit net area recently. Through the investigation of unit plans, a matrix was developed based on the 5 criteria for space composition types. 5 criteria are building stock types, W/D ratio of units, unit net area, number of bay to the main orientation, and openness types. After review the matrix, 10 typical unit types were selected. At the same time, quantitative evaluation indicators were developed based on the 4 criteria such as efficiency, openness, flexibility, environmental sustainability. On each criterion, 3 indicators were developed, and measured on 162 residential unit plans. Firstly, correlation analysis were pursued on 5 criteria for space composition types and 12 quantitative evaluation indicators, and reviewed on each other. Finally, quantitative evaluation indicators of 10 typical unit types were displayed on radar charts in order to show the integrated evaluation on 4 criteria such as efficiency, openness, flexibility, environmental sustainability. From the reviews and radar chart analyses, advantages, disadvantages, and improvements on each typical unit type were presented as research results.