• Journal of Energy Engineering
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• v.19 no.1
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• pp.8-15
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• 2010

As environmental friendly energy system, distributed micro gasturbine is focused on new energy source for overcoming brand new construction area of power generation. This distributed micro gasturbine system has the powerful characteristics as belows; 1) environmental friendly features NOx < 9 ppm, noise < 65 db 2) various fuel flexbility which is used such as natural gas, diesel, low calory new & renewable fuel, kerosene. 3) high specific output power based on small area and is avilable for very easy and compact installation. There are many new installation sites in USA and Japan from 1998. On the other hand the exhisting large power system was constructued by the sea side, this compact power system is now installed by enduser in downtown area and supplying combined heat & power, has the various apllication on-site power generation. In recently, there is the very important issue for new & reliablbe energy development and spreading out. This paper represent as belows for important system characteristics; 1) grid connection modeling 2) system operation characteristics 3) on-site operation result and evaluation output of power quality analysis.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.166-166
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• 2017

금속 재료 중 철강은 기계적 특성이 우수하고 대량생산이 가능하여 선박, 건축, 자동차 등 다양한 분야에 기초재료로써 널리 사용되고 있다. 그러나 스테인리스강 등과 같은 일부 특수한 용도의 강을 제외하고는 부식환경에 취약한 특성을 가지기 때문에 내식성을 향상을 위한 표면처리에 관한 연구가 활발히 진행되고 있다. 가장 일반적으로 습식법(wet process)을 통해 표면상에 아연(Zn)을 도금해 사용하며, 아연이 자체적으로 포함한 희생양극(sacrificial anode) 및 차폐(barrier) 효과가 철강의 부식을 방지하게 된다. 하지만 산업의 고도화에 따라 더욱 가혹해진 노출환경으로 인해 고내식 강재에 대한 수요가 점차 증가하고 있으며, 아연코팅 층의 두께를 증가하여 내식성을 확보하는 방안은 미래 환경 및 자원적인 측면에서 근본적인 해결책으로 제시하기 어려움이 있다. 한편, 건식 프로세스(wet process)로 대별되는 PVD(physical vacuum deposition)에 의해 내식성을 향상시키고자 하는 연구들이 다양하게 진행되고 있다. 이것은 표면에 고순도 양질의 금속 막을 형성시킴으로써 외부환경과의 반응을 효과적으로 제어가 가능하며, 형성된 막은 그 물질의 고유 특성뿐만 아니라 제작 조건에 따른 표면의 기하학적 혹은 결정학적 구조에 의해 크게 영향을 받게 된다. 본 연구에서는 실용금속 중 이온화 경향이 가장 크고 산소와 반응하여 투과성이 작은 산화 피막 형성이 유리한 마그네슘(Mg)을 활용해 표면의 전기화학적 특성을 향상시켰다. 또한 금속 증착 중 진공도조절을 위해 도입되는 불활성 가스로 아르곤(Ar) 및 질소($N_2$)를 사용하여 표면에 형성한 막의 모폴로지 및 결정배향성이 내식성에 미치는 상관관계를 해석하고자 하였다. 실험방법으로 PVD법 중 비교적 간편하고 기초적인 지침을 제시하기 적합할 것으로 고려된 진공증착(vacuum evaporation)법을 이용해 아르곤 및 질소 분위기에서 진공도를 조절하며 용융아연도금상 Mg막을 형성하였다. 제작조건별 막의 기초 특성을 분석하기위해 SEM, EDS, XRD를 이용하였고, 결정배향성(crystal orientation) 분석을 위해 면간격(d-value)과 상대강도(relative intensity)를 확인하였다. 또한 내식성 평가로 염수분무(salt sprat test) 및 양극분극(anode polarization)을 각각 실시하였다. 실험결과에 따르면, Ar 및 $N_2$ 모두에서 가스압이 증가할수록 코팅층의 증착량은 적어지고 입상정(granular structure)의 모폴로지 형성 및 면간격과 상대강도가 증가하는 것이 확인되었다. 또한 쳄버 내 동일 진공도에서, $N_2$ 도입 시 Mg막은 더욱 치밀하고 미세한 입상정의 모폴로지로 형성되며 면간격과 상대강도는 더욱 증가한 것으로 나타났다. 내식성 평가에서 저진공 $N_2$ 조건에서 형성시킨 막이 가장 우수한 내식성이 나타났는데, 이는 상대적으로 불안정하고 반응하기 유리한 입계면적을 많이 포함한 입상정 모폴로지 및 표면에너지가 높은면의 면점유율 증가로 인해 외부환경과의 신속한 반응은 물론 안정적인 피막형성이 용이하였기 때문일 것으로 사료된다. 이상으로 Ar 및 $N_2$ 가스압 조건에 따른 고내식 Mg 막의 유효성을 확인하였고 향후 내식성을 향상시키는 방법으로 응용 가능할 것으로 생각된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.307-311
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• 2014

This study was conducted to evaluate effect of plants number per hill (PNH) on growth and yield of sorghum in drained paddy field for 2 years. Crop growth and development and yield in the field was examined to know the efficiency of proposed cropping system. At seeding after 40 days, leaf number and stem diameter were highest at 1 PNH plot, on the other hands, plant height was at 5 PNH plot the $1^{st}$ and $2^{nd}$, respectively. The harvest stage, 5 PNH plot was highest culm length of 183, 188 cm the $1^{st}$ and $2^{nd}$, however, culm diameter was lowest. Culm length of sorghum was highest by 183, 188 cm at 5 PNH plot also, culm diameter was thickest by 19.18, 20.13 mm at 1 PNH, respectively. Yield components of ear length, seed number per ear and 1000-seed weight were highest at 1 PNH the $1^{st}$ and $2^{nd}$, respectively. As yield of sorghum was highest at 2 PNH plot $344kg{\cdot}10a^{-1}$, $382kg{\cdot}10a^{-1}$ yearly, respectively that it were in order of 1 PNH plot > 3 PNH plot > 4 PNH plot > 5 PNH plot.

• Archives of design research
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• v.19 no.4 s.66
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• pp.155-162
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• 2006

Today, according to population decrease and aging of the old due to the decline of birthrate in our society in $21^{st}$ century, there is a stiff increase of the aged group. Complying with the request of epic needs, as there was a full scale amendment of law of the aged welfare in 1997, the centers appeared differently based on the regional dimension, the difference of the number of persons to be accommodated, and the social and economic characteristics. Coping with these problems occurring, along with the necessity of welfare facilities for the leisure of the aged, the government prepared and carried out a number of plans for the service of the aged and securing of facilities. This practice of the government, however, centered on the crease of service in quantity other than the quality, resulting in a situation of lacking the welfare facilities for the aged meeting the requirement of the aged in their aspect of consumer. On the contrary, building the welfare centers in Japan started in 1960 with a rapid increase of the number of centers in 1970s, and there were 2,214 welfare centers in operation in Japan in 1995, keeping a high level of service in quality and quantity. Thus, this study aims to present basic materials necessary for the criteria of space designing plans for the aged welfare centers in Korea through case analysis of the facility criterion, area constitution and space constitution by the floor that play an important role in regional welfare facilities for the aged in Japan.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.15-24
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• 2010

Until now, the location and the size of gate are designed by only experience and intuitive use judgement. However there are no studies that investigated how many people will be using each subway gate depending on the location of gates. Therefore, the purpose of this study is to develop a gate choice model of subway station. The most critical element of a gate choice in subway station is the location of pedestrian's destinations. In this study, the development of the regression model is constructed from data of land use characteristic of station vicinity and the number of bus route and the space structure of station vicinity(Depth concept by Space Syntax analysis and total road length of station vicinity) by using the real data of 30 subway station in Seoul. This study found that subway pedestrian flow are mainly determined by three factors; the total floor space of commercial buildings, Total Depth(space structure index of station vicinity), and the number of bus route. The verification of a proposed model is done by using the real gate pedestrian data of two subway station in Seoul; Gang-nam and Yang-jae. The additional study of how to define the gate impact area is analysed. Therefore, this study will provide the theoretical bases in decision of gate location and size when a new subway station is opened in future.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.236-240
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• 2007

최근 집중호우에 의한 피해가 증가함에 따라 도시화에 따른 불투수 면적이 유출량 증가의 주요한 원인으로 지목되고 있으며 도시의 인구집중으로 인한 지하수의 난개발로 지하수 오염 및 고갈이 빠르게 진행되고 있다. 이에 도시의 지속적이고 건전한 물 관리를 위하여 우수유출저감시설이 고려되고 있으며, 정량적인 저감효과의 분석방법이 요구되고 있다. 따라서, 본 연구에서는 호주에서 물관리 및 우수유출저감을 고려한 도시유역계획을 위해 이용되고 있는 모형에 대한 민감도 분석을 실시하였으며, 이러한 결과를 바탕으로 MUSIC 향후 국내 우수유출저감시설에 관한 수문 해석시 MUSIC의 적용이 가능할 것으로 판단된다. MUSIC의 매개변수 중 불투수율과 토양특성이 매우 중요한 매개변수로 고려되고 있으므로, 본 연구에서는 투수지역의 최대저류깊이, Soil storage(mm), 강우초기 최대저류깊이의 포화정도 Initial storage(%), 지하수위에 도달할 수 있는 Field capacity(mm), 최대 침투율에 영향을 미치는 건조토양상태의 침투율을 정의하는 계수 a와 함수비 증가에 따른 최대 침투율 감소를 정의하는 지수 b 등의 매개변수에 대해 초기값을 중심으로 일정비율로 각 매개변수를 10단계로 구분하여 민감도 분석을 실시하였다. 주요 매개변수의 민감도 분석 결과로부터 MUSIC의 모의를 위해서는 불투수율의 민감도 변화 범위가 가장 넓고 첨두유출량과 총유출량 변화가 함께 일어나므로, 이를 가장 우선적으로 조정하고 이와 함께 토양특성을 반영하는 Soil storage와 Initial storage를 고려한다면 MUSIC을 이용하여 개발에 의한 유출변화와 다양한 우수침투시설 설치에 따른 저감효과를 합리적으로 예측할 수 있을 것으로 판단된다. 물 관리를 요구하게 되었다. 우리나라는 현실적으로 매년 홍수 피해가 발생하고 있지만, 다른 한편 인구밀도가 높고 1인당 가용 수자원이 상대적으로 적기 때문에 국지적 물 부족 문제를 경험하고 있다. 최근 국제적으로도 농업용수의 물 낭비 최소화와 절약 노력 및 타 분야 물 수요 증대에 대한 대응 능력 제고가 매우 중요한 과제로 부각되고 있다. 2006년 3월 멕시코에서 개최된 제4차 세계 물 포럼에서 국제 강 네트워크는 "세계 물 위기의 주범은 농경지", "농민들은 모든 물 위기 논의에서 핵심"이라고 주장하고, 전 프랑스 총리 미셀 로카르는 "...관개시설에 큰 문제점이 있고 덜 조방적 농업을 하도록 농민들을 설득해야 한다. 이는 전체 농경법을 바꾸는 문제..."(segye.com, 2006. 3. 19)라고 주장하는 등 세계 물 문제 해결을 위해서는 농업용수의 효율적 이용 관리가 중요함을 강조하였다. 본 연구는 이러한 국내외 여건 및 정책 환경 변화에 적극적으로 대처하고 물 분쟁에 따른 갈등해소 전략 수립과 효율적인 물 배분 및 이용을 위한 기초연구로서 농업용수 수리권과 관련된 법 및 제도를 분석하였다.. 삼요소의 시용 시험결과 그 적량은 10a당 질소 10kg, 인산 5kg, 및 가리 6kg 정도였으며 질소는 8kg 이상의 경우에는 분시할수록 비효가 높았으며 특히 벼의 후기 중점시비에 의하여 1수영화수와 결실율의 증대가 크게 이루어졌다. 3. 파종기와 파종량에 관한 시험결과는 공시품종선단의 파종적기는 4월 25일부터 5월 10일경까지 인데 이 기간중 일찍 파종하는 경우에 파종적량은 10a당 약 8${\ell}$이고 늦은 경우에는 12${\ell}$ 정도였다. 여기서 늦게 파종한 경우 감수의 가장

• Journal of Cadastre & Land InformatiX
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• v.49 no.2
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• pp.39-56
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• 2019

In this study, we analyzed the effect of the Eungam Loop Line of Seoul Subway Line 6 on the sale price of adjacent row and multi-family houses on the accessibility and structural characteristics of subway stations. This study empirically analyzed a total of 17,938 cases from 2006 to 2017 based on data on the sale price of row and multi-family houses. In summary, the results of this study using the Hedonic Price Model are as follows. First, this study confirms that the Eungam Loop Line characteristics have a positive effect on the sale price as it is adjacent to the subway station. It is noteworthy that the sale price of 100-200m segment has a positive effect, and the sale price of Bulgwang station, which has excellent mobility and connectivity with CBD, YBD and GBD, has a positive effect. Second, this study shows the locational characteristics such as distance to bus stop, distance to mart, and distance to school have influence on the sale price. Third, this study finds the land characteristics such as land area, land shape, land facing, and road width, have significant effects on the sale price. Fourth, this study discovers the sale price is also is also affected by building and floor characteristics such as the type of housing, building area, the number of households, building age, elevator, and floor level.

• Economic and Environmental Geology
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• v.48 no.5
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• pp.391-400
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• 2015

Korea is a global steel producer and a major consumer while iron ore producing is very low compared to the demand. On the other hand, North Korea holds tremendous amount of iron reserves and, however, its producing rate is limited. Moreover, the data regarding mineral resources of North Korea is very limited and uncertain because of political isolation. This study estimated the amount of iron ore resource and production amount for the Musan Iron mine, the world-known open-pit mine of North Korea, using satellite imagery(Landsat MSS, ASTER) and digital maps between 1976 to 2007. As a result, the mining area of Musan mine was increased by $6.1km^2$ during the 30 years and the mining sector was estimated as $4.9km^2$. We estimated the iron resources and production amount of 0.7 and 0.2 billion metric tons, respectively based on 3D modeling and average iron ore density of Anshan formation in China. This amount indicates 8.1 million tons of annual average production and it coincides well with previous reports. We expect this study would be utilized significantly on inter-Korean exchange programs by providing trustable preliminary data.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.702-709
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• 2014

Luffa cylindrica Roem (sponge gourd) belongs to the Cucurbitaceae family and has been cultivated as an ornamental plant in Korea. Recently, its cultivation area has been increased with an increase in demand for it as an ingredient in cosmetics, herbal medicines, and health supplements. We analyzed inorganic components of sap collected from land race sponge gourds. We also measured antioxidant enzyme activities and antimicrobial activities of the plant, seed, and sap to examine functional properties of sponge gourd. The sap of the sponge gourd contained high levels of K, Ca, P, and Mg, with the most abundant mineral in the sap being K ($470mg{\cdot}L^{-1}$). The amounts of Ca and Mg were 2 and 1.7 times more than those found in cucumber (Cucumis sativus), respectively. Ascorbate peroxidase was more active than catalase and superoxide dismutase in various plant parts of sponge gourd. Antioxidant activities were much lower in stems than in other plant parts such as leaves, roots, flowers, fruits, seeds, and sap. In addition, sap showed a very low level of antimicrobial activity against two food-borne pathogens, Vibrio parahaemdyticus and Propionibacterium acne, and none against the other eight tested food-borne pathogens. Antimicrobial activities against Candida albicans and Malassezia furfur, which causes dermatitis, appeared to be higher in sap than in other parts of sponge gourd plants. Overall, the antimicrobial activity against Malassezia furfur appeared to be higher than against Candida albicans.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.368-377
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• 2000

This study was conducted to examine the recent developments in timber certification schemes at global level such as FSC certification and ISO 14001 system and to analyze their potential impacts on the Korean forest products trade. Data and information on standards and procedure of timber certification and certified forest lands were collected from relevant papers, statistics and reports published by regional and international organizations. In order to analyze the impacts on the Korean forest products trade, questionnaire survey to the affected parties was conducted on acknowledge of key words relating to environment and trade and on the additional amount of willingness to pay for a labeled timber from environmentally sound and sustainably managed forests. Quantities of certified timbers supplied would continue to increase due to lots of timber certification schemes developed and implemented at national, regional and global levels and growing interests in certification from many countries. Demand for certified timbers, however, is far from clear at this stage. The deciding factor would be consumer reaction to the certified products. In the short run, the timber certification would have a little impacts on forest products imports into Korean markets since domestic purchasers do not have much interests in environment related trade measures and their willingness to pay price premiums for certified timbers is not high. However, it could be expected that timber certification has negative impacts on exports of forest products, such as flooring and plywood, to developed European markets where timber certification is used as a trade barrier.