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        검색결과 157

        101.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to estimate optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the offshore Stow Net and the offshore Gill Net fisheries using the current value Hamiltonian method and the surplus production model. As analyzing processes, firstly, this study uses the Gavaris general linear model to estimate standardized fishing efforts of yellow croaker caught by the above multiple fisheries. Secondly, this study applies the Clarke·Yoshimoto·Pooley(CY&P) model among the various exponential growth models to estimate intrinsic growth rate(r), environmental carrying capacity(K), and catchability coefficient(q) of yellow croaker which inhabits in offshore area of Korea. Thirdly, the study determines optimal harvesting production, fishing efforts, and stock levels of yellow croaker using the current value Hamiltonian method which is including average landing price of yellow croaker, average unit cost of fishing efforts, and social discount rate based on standard of the Korean Development Institute. Finally, this study tries sensitivity analysis to understand changes in optimal harvesting production, fishing efforts, and stock levels of yellow croaker caused by changes in economic and biological parameters. As results drawn by the current value Hamiltonian model, the optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the multiple fisheries were estimated as 19,173 ton, 101,644 horse power, and 146,144 ton respectively. In addition, as results of sensitivity analysis, firstly, if the social discount rate and the average landing price of yellow croaker continuously increase, the optimal harvesting production of yellow croaker increases at decreasing rate and then finally slightly decreases due to decreases in stock levels of yellow croaker. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts of the multiple fisheries decreases, but the optimal stock level of yellow croaker increases. The optimal harvest starts climbing and then continuously decreases due to increases in the average unit cost. Thirdly, when the intrinsic growth rate of yellow croaker increases, the optimal harvest, fishing efforts, and stock level all continuously increase. In conclusion, this study suggests that the optimal harvesting production and fishing efforts were much less than actual harvesting production(35,279 ton) and estimated standardized fishing efforts(175,512 horse power) in 2013. This result implies that yellow croaker has been overfished due to excessive fishing efforts. Efficient management and conservative policy on stock of yellow croaker need to be urgently implemented.
        4,900원
        102.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to measure the concentration of odorous compounds and dilution ratio values at each part of the anaerobic digester process with composting facilities using swine manure and food waste. Complex odors, ammonia, volatile fatty acids and sulfur compounds were measured at each part of the process. Complex odors measured during swine manure storage, food waste storage and in the digested liquid tank, were 35,312 Odor Unit(OU), 39,086 OU and 17,733 OU, respectively. The odor contribution index was calculated by the concentration of odorous compounds during each process divided by the threshold limit. As a result, the major odorous compound that appeared during swine manure storage, food waste storage and in the digested liquid tank was hydrogen sulfide. On the other hand, the major odorous compound in the other processes was ammonia. The overall average concentrations of ammonia were highest in the digested liquid tank(337 ppm) and the separated liquid tank(131 ppm). Wastewater treatment process(10.9 ppm) and deodorization process(11.6 ppm) revealed the lowest concentration of ammonia. The overall average concentration of total volatile fatty acids(TVFAs) was 102.8 ppb during food waste storage and among the TVFAs, the main element was propionic acid(66.1 ppb). Sulfur compounds were only detected during swine manure storage, food waste storage and in the digested liquid tank. The dominant sulfur compound was hydrogen sulfide during swine manure storage(96.3 ppm) and methyl mercaptan during food waste storage(17.7 ppm) and dimethyl sulfide during food waste storage(34.5 ppm).
        4,000원
        103.
        2014.09 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 저가의 MEMS 관성 센서와 지자기 센서를 이용하여 자세 정보를 제공받는 자세측정장치(ARHS)를 구현하였다. 저가형 IMU센서와 MCU를 이용하여 운동 자세각을 계산하는 DCM 알고리즘을 설계하고, 3축짐벌에 장착하여 연산결과의 정확도를 측정하였다. DCM 알고리즘을 이용 연산된 자세각의 정확도는 roll 및 pitch에 대하여 약 1.1%로 나타났으며, yaw각의 경우는 3.7%로 나타났다. Yaw 각의 경우에는 스텝핑 모터를 구동하는 실험환경에 따른 교란의 영향으로 그 오차가 상대적으로 크게 나타난 것으로 평가되었다. 짐벌 실험장치를 이용한 센서의 검증에서 더욱 정밀한 실험을 위해서는 주변 환경 요인에 대한 제어가 요구될 것으로 보이며, 실험장치의 스테핑 모터 구동 시 발생하는 진동 및 자기장의 영향과 실험 장치의 금속성 구조물의 영향으로 생각되는 센서 데이터의 오차 및 불안정 상태를 차단할 수 있는 장치의 보완이 필요할 것으로 보인다. 그리고 지자기 센서의 경우 좁은 범위의 측정에 추가하여 넓은 범위의 측정도 보완되어야 할 것으로 생각된다.
        4,000원
        104.
        2014.06 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 저가, 저전력 및 소형의 IMU를 구성하기 위한 MEMS 관성 센서를 이용하여 자세 정보를 제공받는 ARHES에 위의 센서를 사용하기 위해 자이로 센서 및 가속도센서의 데이터 출력 특성을 검증하여 오차 및 정확도를 분석하였다. 센서 실험을 위하여 진자 실험 장치를 제작하였고, 진자 운동에 대한 센서 데이터를 수집하였다. 이론적인 수식을 유추하여 센서 데이터의 정확성 분석을 위한 기준 값으로 설정하였다. 센서값과 이론값을 비교하면 각속도에서 4.32~5.72%, 가속도에서 x-, z-축 방향에 대하여 각각 3.53~6.74% 및 3.91~4.16%의 오차율을 나타냈다. 진자실험 장치를 이용한 센서 검증에서 무인헬리콥터에 사용될 센서로서 적합한 것으로 평가되었으며 이는 짐벌장치 등을 이용한 자세추정 알고리즘을 구성하는데 기초가 되었다. 또한, 더욱 정밀한 실험을 위해서는 온도 등 주변 환경 요인에 대한 보정이 요구된다.
        4,000원
        105.
        2013.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To understand how reactivity between reinforcing nanoparticles and aqueous solution affects electrodeposited Cu thin films, two types of commercialized cerium oxide (ceria, CeO2) nanoparticles were used with copper sulfate electrolyte to form in-situ nanocomposite films. During this process, we observed variation in colors and pH of the electrolyte depending on the manufacturer. Ceria aqueous solution and nickel sulfate (NiSO4) aqueous solutions were also used for comparison. We checked several parameters which could be key factors contributing to the changes, such as the oxidation number of Cu, chemical impurities of ceria nanoparticles, and so on. Oxidation number was checked by salt formation by chemical reaction between CuSO4 solution and sodium hydroxide (NaOH) solution. We observed that the color changed when H2SO4 was added to the CuSO4 solution. The same effect was obtained when H2SO4 was mixed with ceria solution; the color of ceria solution changed from white to yellow. However, the color of NiSO4 solution did not show any significant changes. We did observe slight changes in the pH of the solutions in this study. We did not obtain firm evidence to explain the changes observed in this study, but changes in the color of the electrolyte might be caused by interaction of Cu ion and the by-product of ceria. The mechanical properties of the films were examined by nanoindentation, and reaction between ceria and electrolyte presumably affect the mechanical properties of electrodeposited copper films. We also examined their crystal structures and optical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy.
        4,000원
        106.
        2013.09 구독 인증기관 무료, 개인회원 유료
        As the balcony expansion of residential building was legalized, the expansion generation is tend to increased continuously of existing residential building or condominium complex. But balcony is the service area. So, it is worried about defect occurrence of extension construction because thermal insulation effect is insufficient to balcony installed an aluminum sash. Therefore, it is desired the method to minimize the damage of performance improvement of the windows which has an influence directly on the performance defect. See-through a-si is effective to reduce the cooling loads and sunlight, to produce the electricity by installing a-si at the wall and windows of residential building. This paper has predicted producing electricity and have analyzed heating/cooling load based on balcony expansion and building-integrated PV installation in residential building.
        4,000원
        107.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 해저케이블 부두 하역용 장비인 코일링 암(coiling arm)에 대한 국산화 자체개발 내용 중 구조설계 및 해석 결과 내용을 제시하였다. 상세 구조설계를 위해 3차원 CAD 프로그램을 이용하여 고 정밀도의 모델링을 수행하였고, 유한요소 기법을 이용하여 전산구조해석을 수행하였다. 코일링 암의 활용 목적에 맞추어 하역대상 케이블을 선박에서 케이블 탱크로 하역시 효과적으로 가이드 할 수 있도록 베어링 및 롤러 부품을 설계하여 메인 암이 회전하고 케이블 가이드가 이동할 수 있도록 하였고, 기존의 외국 모델에서 사용하던 와이어 및 모터 시스템을 이용한 케이블 가이드 작동방식을 유압 시스템을 이용한 작동방식으로 변경하여 원가절감을 달성하면서 사용자가 직관적으로 작동할 수 있도록 설계하였다. 장비 자체의 자중 및 하역 케이블 하중조건에 대한 응력 해석을 수행하였고, 유압시스템의 과작동에 따른 파손 가능성을 고려하였다. 케이블 가이드의 운동 및 설치 지면의 경사도에 따른 전복 안전성 해석을 수행하였으며, 설치장소의 풍하중 효과도 추가로 고려하였다. 본 연구를 통해 기존 수입품 코일링 암의 작동방식 개선과 독자적인 구조설계 및 해석 방법을 확립하였으며, 실제 국내 최초로 자체 개발된 제품의 현장설치 완료 및 하역작업의 효율적이고 정상적인 운영을 완료 및 검증하였다.
        4,000원
        108.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, extensive research has been performed in the field of orthopedic medicine to develop cell-based therapies for the restoration of injured bone tissue. But there has been rarely reported about rehabilitaton of oral and maxillofacial bone defect using self-derived osteoblasts. Normal human osteoblast cell(NHost) was previously established into marrow-derived human mesenchymal stem cells for their capacity to proliferate and differentiate into osteoblasts under various culture conditions. The purpose of this study was to examine proliferation and differentiation of NHosts effected by growth factors with ALP activity and RT-PCR. After NHosts were cultured under basal and osteogenic medium at 37℃ and 5% CO2, they were analyzed by ALP activity and RT-PCR. BMP-2 under osteogenic medium decreased growth rate of NHosts compared to under osteogenic medium. BMP-2 under osteogenic medium induced osteoblastic differentiation in NHosts by increased ALP activity. The differentiating capacity of NHosts under osteogenic medium showed that NHosts expressed higher mRNA expression levels of OSX and OCN, while that of RUNX2 decreased after BMP-2 treatment. It suggested that NHosts having characteristics of osteoprecursor cells might be more advanced in their osteogenesis development by BMP-2, making NHosts an interesting biological tool for treatment of skeletal defects and diseases of oral and maxillofacial bone.
        4,000원
        109.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 해상용 부이(bouy)의 전원공급용 풍력 발전기 개발하였으며, 이는 특허 기술 및 SVAWT 모델 개발의 다양한 경험을 바탕으로 실시되었다. 구조 및 진동 안전성의 확인을 위한 방법으로 자체 개발한 디자인 프로그램과 첨단 공학 기술, 전산 유체 역학, 유한 요소법 및 전산 구조 역학이 사용되었다. 특별 로딩 및 해양 부이의 동적 움직임을 유도해서 파도에 의한 진동 조건으로도 간주되었다. 이 디자인은 특별 설계되었고, 특허 에어포일 형상은 테스트를 거쳐 바다 부이의 제한된 설치 공간에 따라 최대 출력을 얻는데 적용되었다. 여러 SVAWT 모델이 구축 되었으며 실제로 부이에 장착되어 바다에서 테스트 중이다.
        4,000원
        110.
        2012.03 구독 인증기관 무료, 개인회원 유료
        With the development of artificial lighting technology, human can breakout the limitation of the natural light and make it possible to create a brilliant civilization. However, the wide used outdoor artificial lighting caused severe environmental problem called "Light Pollution" due to human's less cognition of using light and excessive light. Obtrusive light at nighttime can do harm to the human health and observation activity. In this paper, the upward light control process of general lighting fixtures was suggested for reducing the adverse effects such as sky glow in the central city and light trespass in the residential areas.
        4,000원
        111.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Environmental lighting zone-setting has suggested regulatory standards according to the influence of artificial illumination on natural environment and human life. Then, it is necessary to check out the viability of environmental lighting zone division as it is limited to use-zone division. This study aims to suggest some problems, which occur when environmental lighting zone is set by use-zone only, by comparing and analyzing the artificial illumination luminance. In addition, this study aims to suggest basis for the environmental lighting zone-setting and eventually, more effective environmental lighting zone division.
        4,000원
        112.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to look at how pepper was used in traditional medicine. In other words, this study aims to take a look at the process by which the medicinal nature & efficacy of pepper in traditional society was perceived and arranged through the aspects of the use of pepper as an exotic crop for treating diseases. This study investigated cases of using pepper for medical treatments by referring to books on traditional medicine in Korea. The old records about pepper are mainly in empirical medical books from the late Chosun dynasty. Nevertheless, the records about pepper tend to decrease in medical text as time goes by. Such a phenomenon can be attributable to the fact that people began to use pepper for daily food life rather than for medicinal purposes. Pepper was used mostly for digestive trouble such as vomiting, diarrhea, and stomachaches, and it was also applied to mental and aching diseases caused by the sound of body fluids remaining in the stomach. In addition, there were many cases where pepper was used externally for surgical disorders. Such symptoms for treatment are linked to, or in a complementary relationship with, research results in modern times. Boiled pepper was generally taken in the traditional herbal decoction method, and in the case of surgical diseases, it was applied externally. The cases of using old pepper, using pepper with seeds or without seeds, and using pepper mixed with sesame oil belong to a sort of herbal medicine processing, which usually aimed at changing the medicinal nature of pepper. In addition, in relation to the eating habits at that time, pepper was used as seasoning and to make red pepper paste with or without vinegar. There are two words used for pepper in the medical textbooks, 苦椒 (gocho) and 烈棗 (yeoljo). These words are translated into Korean as gochu, so we can identify this word as a nickname for pepper.
        4,000원
        113.
        2011.09 구독 인증기관 무료, 개인회원 유료
        This study fouces on the electricity generation of B1PV system in the super-tall buildings. To improve the efficiency of the B1PV system, solar irradiance and air temperature should be taken into consideration. This study does research on, one of two main parameters, the solar irracliance in the super high-rise buildings. According to the measurement of solar irracliance, it increased with altitude. It is, particularly, more obviously in the super-tall buildings than others. Subsequently, to make an accurate B1PV elecrticity generation prediction,it is necessary to anaiyze the solar irracliance distribution on the super-taII building's facade which is a prerequisite for optimal B1PV system design.
        4,000원
        114.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Environmental lighting zone-setting has suggested regulatory standards according to the influence of artificial illumination on natural environment and human life. Then, it is necessary to check out the viability of environmental lighting zone division as it is limited to use-zone division. This study aims to suggest some problems, which occur when environmental lighting zone is set by use-zone only, by comparing and analyzing the artificial illumination luminance. In addition, this study aims to suggest basis for the environmental lighting zone-setting and eventually, more effective environmental lighting zone division.
        4,000원
        115.
        2011.03 구독 인증기관 무료, 개인회원 유료
        The paper mainly discusses on the method how to save energy so as to follow the "Low Carbon and Green Growth" by the govemment and the Building Energy Efficiency Rating System. For the purpose of interior comfort as well as effective operation and management of buildings, this paper does basic research on development of elementary technology for saving the energy used in building. In this paper, the interior lighting control zone is selected to make a lighting control algorithm which takes the reduction of building energy into consideration for saving building energy when the building envelopes are replaced by the BIPV system.
        4,000원
        116.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적: 본 연구는 고함수 하이드로젤 렌즈를 제조하기 위해 일반적으로 사용되는 콘택트렌즈의 재료와 MPTS(methacryloxypropyl tris(trimethylsiloxy)silane) 및 DMA(N,N-dimethylacrylamide)를 각각 첨가하여 중합한 후 이 재료들의 첨가 비율을 증가시켜 물리적 특성을 평가하였다. 방 법: MPTS와 DMA를 교차결합제인 EGDMA와 HEMA, NVP, MMA 그리고 개시제인 AIBN을 사용하여 캐스트 몰드법으로 공중합 하였다. 결 과: 실험결과, DMA를 첨가하여 제조한 콘택트렌즈의 함수율은 43.32~64.65%, 산소전달률(Dk)은 13.55~33.55×10(-11)(cm2/sec)(mlO2/ml×mmHg)이었다. MPTS를 첨가하여 제조한 콘택트렌즈의 경우, 함수 율은 41.02~47.62%, 산소전달률(Dk)은 13.88~20.38×10-11(cm2/sec)(mlO2/ml×mmHg)이었다. DMA가 첨가된 조합에서는 함수율이 증할수록 산소전달률(Dk)이 증가하는 경향을 보였지만 MPTS가 첨가된 조합에서는 함수율이 증가하여도 산소전달률(Dk)은 일정하게 유지되는 경향을 보였다. 결 론: 본 실험결과로 볼 때 생성된 공중합체는 고함수율을 가진 안의료용 재료로 사용될 수 있을 것으로 판단된다.
        4,000원
        117.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 Water Gas Shift (WGS) 반응이 일어나는 분리막 반응기 (MR) 대상공정에 대해서 동적모사 (dynamic simulation)를 실시하고 시간과 위치에 따른 온도 및 수소 농도 변화 등을 살펴보았다. 모사 결과에 의하면 도입부에서 반경방향으로의 수소 농도, 수소 분압 및 온도차가 가장 컸으며 출구에서 가장 작았다. 또한, 수소분압의 차이가 가장 큰 도입부에서 수소의 flux가 가장 크게 나타나며 출구에서 일산화탄소의 전환률은 0.65였다.
        4,000원
        118.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Light pollution is a side effect of industrial civilization. It obscures the stars in the night sky for city dwellers, interferes with astronomical observatories, and, like any other form of pollution, disrupts ecosystems and has adverse health effects. It is most severe in highly industrialized, densely populated areas of North Arnerica, Europe, and Japan. Nowadays, light pollution has become a global problem and the public concerns on disputes of light pollution have been on the rise. Unfortunately, we haven't had any comprehensive and systematic regulation of lighting pollution yet. Therefore, we need to make our own regulation of lighting pollution to deal with it. The purpose of this study is making a research on the standards and countermeasures of light pollution at home and abroad before establishing our own regulation based on which we can resolve and reduce the light pollution.
        4,000원
        119.
        2009.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전라북도 전주시의 전주천에서 2000년 4월부터 2002년 12월까지 상류인 한벽교부터 삼천 합류지점까지 도심을 관통하는 7.2km의 구간에서 "자연형하천 조성사업" 이루어졌으며, 이에 대한 전주천의 자연형 하천 조성 사업 전과 후의 어류상 및 군집을 조사하였다. 조사 결과 조성사업 이전인 1975년부터 1999년까지 전주천에서는 12종~8종의 어류가 출현하였으나, 공사 이후인 2003년~2008년 사이에는 총 34종이 확인되어 어류의 다양성이 크게 향상되었다. 특히 도심지인 중류지점 (다가교-서신교사이)에서는 공사이전에는 5종의 적은 종이 출현하였으나 공사 이후에는 22종으로 급증하는 특징을 보였다. 이러한 어류상의 변화는 자연형 하천 공사로 인해 생활하수의 유입 차단으로 인한 전주천의 수질개선 및 직강화 되고, 평탄화 되어 있던 하천에서 여울과 소가 반복적으로 나타났으며, 또한 하상구조도 돌과 자갈, 모래, 진흙 등으로 다양화되어 어류의 서식공간이 다양화되었기 때문으로 생각된다.
        4,200원
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