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        검색결과 280

        81.
        2016.03 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 문턱치 기반의 영상처리 알고리즘을 이용한 인셀(in-shell)헤이즐럿과 셀드(shelled)헤이즐럿의 분류 방법을 제안한다. 헤이즐럿은 외피가 있는 인셀 형태, 내피만 있는 셀드 형태, 내피도 제거된 블랜치드 (blanched)형태, 그리고 모든 껍질을 제거한 후 알맹이를 볶아 판매하는 로스티드(roasted)형태로 제품화 된다. 그러나 생산, 이송과 가공 과정에서 외피가 쉽게 박피되기 때문에 각 단계별로 제품을 판매하기 위해서는 일차적으로 인셀 헤이즐럿과 셀드 헤이즐럿을 구별하여 제품화하는 것이 필요하다. 따라서 본 논문에서는 각 단계의 헤이즐럿 표면에 대한 영상처리 기반 분석을 바탕으로 18개의 문턱치 기반의 선별인자를 얻고 이를 바탕으로 실시간 선별이 가능한, 인셀 및 셀드 헤이즐럿의 분류 알고리즘을 제안한다. 제안한 방법을 선별에 적용한 결과 인셀 헤이즐럿의 선별 정확 도는 98%이며 나머지 셀드 헤이즐럿의 선별 정확도는 94%를 보였다.
        4,300원
        82.
        2016.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Pt@Cu/C core-shell catalysts were successfully prepared by impregnation of a carbon support with copper precursor, followed by transmetallation between platinum and copper. The Pt@Cu/C core-shell catalysts retained a core of copper with a platinum surface. The prepared catalysts were used for hydrogen production through catalytic dehydrogenation of decalin for eventual application to an onboard hydrogen supply system. Pt@Cu/C core-shell catalysts were more efficient at producing hydrogen via decalin dehydrogenation than Pt/C catalysts containing the same amount of platinum. Supported coreshell catalysts utilized platinum highly efficiently, and accordingly, are lower-cost than existing platinum catalysts. The combination of impregnation and transmetallation is a promising approach for preparation of Pt@Cu/C core-shell catalysts.
        4,000원
        89.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, effect of core-shell structure on compaction behavior of harmonic powder is investigated. Harmonic powders are made by electroless plating method on Fe powders. Softer Cu shell encloses harder Fe core, and the average size of Fe core and thickness of Cu shell are 34.3 μm and 3.2 μm, respectively. The powder compaction procedure is processed with pressure of 600 MPa in a cylindrical die. Due to the low strength of Cu shell regions, the harmonic powders show better densification behavior compared with pure Fe powders. Finite element method (FEM) is performed to understand the roll of core-shell structure. Based on stress and strain distributions of FEM results, it is concluded that the early stage of powder compaction of harmonic powders mainly occurs at the shell region. FEM results also well predict porosity of compacted materials.
        4,000원
        90.
        2015.03 구독 인증기관 무료, 개인회원 유료
        The heating & cooling performance of vapor compression heat pump using seawater heat source has been investigated experimentally for fish farm heat supply system. The principal parts of the heat pump systems are compressor, condenser, expansion devices and evaporator. The evaporator and condenser are both heat transfer devices. We used double pipe H/E(CASE-1) and shell&coil H/E(CASE-2) as evaporator, condenser of heat pumps. The experimental results were higher Uvalue 25% of double pipe heat exchanger compared to shell & coil H/E. The COPc is 4.74 and the COPH is 6.18 of the heat pump with shell & coil H/E.
        4,000원
        91.
        2014.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We study the physical and chemical properties of the molecular clump hosting a young stellar cluster, IRAS 20160+3636, which is believed to have formed via the “collect and collapse” process. Physical parameters of the UC Hii region associated with the embedded cluster are measured from the radio continuum observations. This source is found to be a typical Galactic UC Hii region, with a B0.5 type exciting star, if it is ionized by a single star. We derive a CN/HCN abundance ratio larger than 1 over this region, which may suggest that this clump is being affected by the UV radiation from the Hii region.
        4,000원
        92.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        SnO2-CoO/carbon-coated CoO core/shell nanowire composites were synthesized by using electrospinning and hydrothermal methods. In order to obtain SnO2-CoO/carbon-coated CoO core/shell nanowire composites, SnO2-Co3O4 nanowire composites and SnO2-Co3O4/polygonal Co3O4 core/shell nanowire composites are also synthesized. To demonstrate their structural, chemical bonding, and morphological properties, field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were carried out. These results indicated that the morphologies and structures of the samples were changed from SnO2-Co3O4 nanowires having cylindrical structures to SnO2-Co3O4/Co3O4 core/shell nanowires having polygonal structures after a hydrothermal process. At last, SnO2-CoO/carbon-coated CoO core/shell nanowire composites having irregular and high surface area are formed after carbon coating using a polypyrrole (PPy). Also, there occur phases transformation of cobalt phases from Co3O4 to CoO during carbon coating using a PPy under a argon atmosphere.
        4,000원
        94.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 날치 난소막에서 추출한 날치 난소막 추출물(Flying fish Roe Shell Extract, 이하 FRSE라 명함)의 물리화학적인 특성을 조사하기 위하여 수행되었다. 해양성 원료인 날치 난소막에서 FRSE를 제조하여 물리화학적인 특성을 분석하였다. 영양성분 조성을 분석한 결과 FRSE는 81.00%의 단백질과 9.12%의 회분, 그리고 4.48%의 수분으로 구성되어있는 것으로 나타났다. 아미노산 조성분석 결과 FRSE는 콜라겐 펩타이드의 특징인 OH-proline과 glycine이 검출되었으며, 포도당과 지방 대사에 관여하는 glutamic acid 와 aspartic acid 함량이 높게 검출되었다. 또한 열량분석 결과에서는 100g의 FRSE가 347 kcal의 열량을 지니고 있는 것으로 나타났다. FRSE의 분자량 분석 결과에서는 약 1,300 Da정도의 평균분자량 분포를 나타낸다는 것을 알 수 있었다.
        4,000원
        95.
        2014.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We synthesized Fe-doped TiO2/α-Fe2O3 core-shell nanowires(NWs) by means of a co-electrospinning method anddemonstrated their magnetic properties. To investigate the structural, morphological, chemical, and magnetic properties of thesamples, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectronspectroscopy were used, as was a vibrating sample magnetometer. The morphology of the nanostructures obtained aftercalcination at 500oC exhibited core/shell NWs consisting of TiO2 in the core region and α-Fe2O3 in the shell region. In addition,the XPS results confirmed the formation of Fe-doped TiO2 by the doping effect of Fe3+ ions into the TiO2 lattice, which canaffect the ferromagnetic properties in the core region. For comparison, pure α-Fe2O3 NWs were also fabricated using anelectrospinning method. With regard to the magnetic properties, the Fe-doped TiO2/α-Fe2O3 core-shell NWs exhibited improvedsaturation magnetization(Ms) of approximately ~2.96emu/g, which is approximately 6.1 times larger than that of pure α-Fe2O3NWs. The performance enhancement can be explained by three main mechanisms: the doping effect of Fe ions into the TiO2lattice, the size effect of the Fe2O3 nanoparticles, and the structural effect of the core-shell nanostructures.
        4,000원
        97.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new shell divider was manufactured according to the principle of the lever in order to improve working efficiency in collecting the gonad of Sea Urchin, Anthocidaris crassispina, around the coast of jeju. It was composed of three parts of a pair of handles for grasping power, a fulcrum and a pair of knives for action with 21cm in length and 13cm in width. The operating efficiency of the shell divider was tested out in three place of Jeju coast. Statistical significances of differences of working time between test groups were calculated according to the t-test with the level of significance . In dividing the shell of sea urchin, the average of about 3 seconds of working time by the shell divider was less than that by a knife. At the result of t-test, the statistical significance in the working time existed between the divider group and the knife group. On the other hand, the working time among the divider operators showed no significant differences. It is concluded that the shell divider is more efficient than a knife in traditional operating.
        4,000원
        98.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An accident from machine work is often fatal to the worker. This accident is mostly preventable through perfect process jig. In case of this machine work, however, the disaster frequently occurred because of the design which is not considered the beginning of product design, post-process and mass process of production. As for sand casting method, this has the merits of the production; the product is easily produced by manual labor. On the other hand, this method has the demerits of a bigger dimensional error contrary to other mass process of production. When the sand casting product is in machine work, there are various problems such as unsafe fix and excessive cutting, product desorption and rapid life depreciation of equipment and tools. Considering the characteristics of sand casting method, it is accepted as difficulty to improve the problems. In this study, it suggests shell mold method for mold instead of the machine work after the sand casting of the circle shape container product. And the surface accomplishes the following average of surface roughness Ra9.94 ㎛ of machine work with the casting of flask mold by shell mold method. In accordance with the simplification of processing process and reducing the average thickness variation by mass production of product with detailed appearance, it has a good influence on safety accident prevention caused by production and damaged product. It is confirmed that making higher degree of size precision of all machine work product is possible to increase the safety and productivity, reduce the processing process and improve environment.
        4,000원
        99.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study carried out finite element deflection analysis of cylindrical shell structures made of composite materials, which is based on the micro-mechanical approach for different fiber-volume fractions. The finite element (FE) models for composite structures using multi-scale approaches described in this paper is attractive not only because it shows excellent accuracy in analysis but also it shows the effect of the material combination. New results reported in this paper are focused on the significant effects of the fiber-volume fraction for various parameters, such as fiber angles, layup sequences, and length-thickness ratios. It may be concluded from this study that the combination effect of fiber and matrix, largely governing the dynamic characteristics of composite shell structures, should not be neglected and thus the optimal combination could be used to design such civil structures for better dynamic performance.
        4,000원
        100.
        2013.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated purplish Washington clam, Saxidomus purpuratus on its gonadal development, reproductive cycle and shell length (age) at 50% female group maturity from January to December 2011 in Jinhae Bay, Korea. This species is dioecious. The gonad index (GI) began to increase in January, reached the maximum value in May and to decrease in June, reached the minimum value in September then to increase slowly in October again. The reproductive cycle of the clams can be divided into five successive stages: the early active stage (Ea, from February to March), the late active stage (La, from January to March and October to December), the ripe stage (R, from January to May), the spawning stage (S, from June to December) and the degenerative and inactive stage (Ia, from January to February and November to December). The spawning periods were from June to December and the main spawning periods were from July to October. The shell length at 50% female group maturity (SL50) was estimated to be 63.6 mm, which can be converted as sexual maturity age of 2.2 year.
        4,000원
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