• Title/Summary/Keyword: 단분산

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A STUDY ON THE RACIAL CLASSIFICATION OF ASIAN CHUM, ONCORHYNCHUS KETA(WALBAUM) BASED ON SCALE CHARACTERISTICS (인상(鱗相)에 의한 아시아계 백연어, Oncorhynchus keta(Walbaum)의 계통판정에 관한 연구)

  • KANG Yong Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.2
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    • pp.91-97
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    • 1974
  • Two scale characters, the width ana circuli counts of the first-year band, were used in a discriminant function analysis to see how effectively the two scale characters would separate geographical chum stocks from the western North Pacific. A total of 476 scale samples were taken from spawning adults which ascended to rivers of Hokkaido, Japan, in 1956, and Kamchatka, the U.S.S.R., in 1957. The scale characters were examined for conformity to the statistical requirements of a discriminant function. As a result of the examinations the two characters were verified to be able to be used in a discriminant function analysis that would classify chum taken on the high seas to most Probable origin. A discriminant function computed using the two characters correctly classified 78.5 percent of the Hokkaido and Kamchatka chum fish. Of the two characters the number of the circuli could alone classify fish to its origin with nearly the same probability of correct classification as the discriminant function based on the two characters can.

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Graphene Quantum Dot Interfacial Layer for Organic/Inorganic Hybrid Photovoltaics Prepared by a Facile Solution Process (용액 공정을 통한 그래핀 양자점 삽입형 유/무기 하이브리드 태양전지 제작)

  • Kim, Youngjun;Park, Byoungnam
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.646-651
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    • 2018
  • This paper reports that the electronic properties at a $P3HT/TiO_2$ interface associated with exciton dissociation and transport can be tailored by the insertion of a graphene quantum dot (GQD) layer. For donor/acceptor interface modification in an $ITO/TiO_2/P3HT/Al$ photovoltaic (PV) device, a continuous GQD film was prepared by a sonication treatment in solution that simplifies the conventional processes, including laser fragmentation and hydrothermal treatment, which limits a variety of component layers and involves low cost processing. The high conductivity and favorable energy alignment for exciton dissociation of the GQD layer increased the fill factor and short circuit current. The origin of the improved parameters is discussed in terms of the broad light absorption and enhanced interfacial carrier transport.

Logic of the Cooperative Management for the Private Forest (사유림(私有林) 협업경영(協業經營)의 논리(論理))

  • Kim, Jong Kwan
    • Journal of Korean Society of Forest Science
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    • v.77 no.2
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    • pp.242-251
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    • 1988
  • Private forestland in Korea occupies about 48 percent of the total land area. But, the ownership size is too small to expect self-supporting management of forestowners. In order to improve individual management of the small-sized forest through the to the state of self-support, a cooperative forest management has been demanded, enlargement of the size of the management units by combining the different individual management units. The cooperative management of the private forest is to combine forestry production factors such as forestland, labor-power, and capitals according to the agreement. For the cooperative forest management, a proper plan should be established and well-trained working-crew should be produced. In addition, forestry facilities should be provided and operated jointly. Though the cooperative forest management by owners is considered to be favorable theoretically, it is difficult for forestowners including many nonresidents to organize the forest management cooperatives without outside help. Therefore, intensive pulblication and extension programmes are required and a financial support by the government should be followed.

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Influence of Service Quality of Aged Sports on Service Satisfaction for Non-profit Organization (비영리조직의 노인체육 서비스품질이 서비스만족에 미치는 영향)

  • Lee, Tae-Yong;Cho, Song-Hyeon;Song, Kang-Young
    • The Journal of the Korea Contents Association
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    • v.8 no.11
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    • pp.375-385
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    • 2008
  • This research was conducted with the aim of providing basic data to a non profit organization's strategies by determining the influence of the service quality cognition of the aged people's excercise program on service satisfaction. The subject of this study was sixteen districts in city B, and aged people who participates in the district's exercise programs. 320 subjects were selected based on a purposeful sampling, and the survey sheets of 308 subjects, excluding 12 of those who lacked sincerity were used for th analysis. To prove the hypothesis of the study based on the sampled data, t-test, One-way ANOVA and regression analysis were conducted using the SPSS Ver. 12.0 statistics program, and the results are as follows: First, perceived service quality differed, but service satisfaction did not differed on the gender. Second, perceived service quality partially differed, but service satisfaction did not differed on the age. Third, perceived service quality partially differed, but service satisfaction did not differed on the frequency. Fourth, perceived service quality and service satisfaction partially differed depending on the period. Fifth, performance, out of the perceived service quality factor, was found to had positive influence on service satisfaction.

Nano-emulsion Containing Parthenocissus tricuspidata Stem Extracts for Enhanced Skin Permeation and the Antibacterial Activity of the Extracts (피부 흡수 증진을 위한 담쟁이덩굴 줄기 추출물 함유 나노에멀젼 및 이의 항균활성 연구)

  • Jo, Na Rae;Park, Min A;Jeon, So Ha;Park, Soo Nam
    • Microbiology and Biotechnology Letters
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    • v.41 no.3
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    • pp.320-326
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    • 2013
  • In a previous study, we investigated the antioxidative and cellular protective effects of Parthenocissus tricuspidata stem extracts. In this study, we prepared nano-emulsion containing P. tricuspidata stem extract to improve skin permeation. The particle size of the nano-emulsion using the microfluidizer was 302 nm. Its loading efficiency was over 86%. The size distribution of the nano-emulsion took a monodispersed form and the nano-emulsion was more stable than typical emulsion without using microfluidizer during a 2 week period. In vitro skin permeation study of nano-emulsion containing P. tricuspidata stem extracts was carried out using Franz diffusion cell. The 1,3-butylene glycol used as a control group had 32.59% skin permeation efficiency. The skin permeation efficiency of the nano-emulsion was 42.47%. Also, we observed the antibacterial activity of the ethyl acetate fraction on skin flora for prospective applications as a natural antimicrobial. The ethyl acetate fraction had antibacterial activities higher than methyl paraben on Staphylococcus aureus, and Bacillus subtilis. These results indicate that nano-emulsion containing P. tricuspidata stem extracts could possess valued applications in cosmetic formulations for improving skin permeation. Also, based on the antibacterial activities on skin flora, antioxidative and cellular protective effects shown in our previous study, we suggest that P. tricuspidata stem extracts could be used as functional cosmetic materials.

Petrology of the Cretaceous Igneous Rocks in the Mt. Baegyang Area, Busan (부산 백양산 지역의 백악기 화산-심성암류에 대한 암석학적 연구)

  • 김향수;고정선;윤성효
    • The Journal of the Petrological Society of Korea
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    • v.12 no.1
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    • pp.32-52
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    • 2003
  • The Mt. Baegyang in Busan, composed of sedimentary basement rocks (Icheonri Formation), andesite (lava), andesitic pyroclastic rocks, fallout tuff and tuffaceous sedimentary rocks, rhyolitic pyroclastic rocks, intrusive rocks (granite-porphyry, felsite, and biotite-granite) of Cretaceous age in ascending order. The volcanic rocks show a section of composite volcano which comprised alternation of andesitic lava and pyroclasitc rocks, rhyolitic pyrocalstic rocks (tuff breccia, lapilli tuff, fine tuff) from the lower to the upper strata. From the major element chemical analysis, the volcanic and intrusive rocks belong to calc-alkaline rock series. The trace element composition and REE patterns of volcanic and plutonic rocks, which are characterized by a high LILE/HFSE ratio and enrichments in LREE, suggest that they are typical of continental margin arc calc-alkaline rocks produced in the subduction environment. Primary basaltic magma might have been derived from partial melting of mantle wedge in the upper mantle under destructive plate margin. Crystallization differentiation of the basaltic magma would have produced the calc-alkaline andesitic magma. And the felsic rhyolitic magma seems to have been evolved from andesitic magma with crystallization differentiation of plagioclase, pyroxene, and hornblende.

Evaluation on the Mechanical Performance of Concrete Using Entanglement Polyamide Fiber (다발형 폴리아미드섬유 보강 콘크리트의 역학적 성능평가)

  • Jeon, Joong Kyu;Kim, Gyu Yong;Jeon, Chan Ki;Lee, Soo Choul
    • Journal of the Society of Disaster Information
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    • v.8 no.3
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    • pp.223-233
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    • 2012
  • Steel fiber is high stiffness and large weight. So, Pumping hose to rupture of the safety management is difficult. Steel fiber caused by corrosion of the deterioration of durability and high-rebound losses are needed for the improvements. Thus, the revised regulations in 2009 by a steel fiber to reinforce other materials is possible. Variety of fiber reinforcement material for concrete review of applicability is needed. Steel fiber strength than the other fibers is large and by the geometry of the fibers are attached to improve performance. However, compared to steel fiber organic fibers and low modulus of elasticity and tensile strength of fiber and agglomeration occurs in the concrete to be used as reinforcement material is difficult. In this regard, the present study as a single object in the micro-fiber bouquet sharp entanglement through make muck attach surface area, distributed fibers from surfactant of the surface enhanced polyamide fibers, steel fiber and PP fiber reinforced concrete by comparing the scene to provide a basis for the use.

Ultrastructure of the Androgenic Gland of the Freshwater Prawn, Macrobrachium nipponense (징거미새우, Macrobrachium nipponense의 Androgenic Gland 미세구조)

  • 김대현;강정하;김대중;한창희
    • Development and Reproduction
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    • v.3 no.1
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    • pp.53-58
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    • 1999
  • The androgenic gland secretes a hormone, androgenic gland hormone, which is believed to act on the differentiation of the primary, secondary, and behavioral sex characteristics in most malacostracan crustaceans. This report presents the ultrastructural morphology of the androgenic gland in the freshwater prawn Macrobrachium nipponense. This gland, located in the coxopodite of the last pair of walking legs, was attached to the subterminal region of the sperm duct. The gland was composed of simple cellular strands, encased by a fibrous sheath. Microvilli were situated in the fibrous sheath, especially at the edge of each cellular strand. The androgenic gland cells had the large and round nucleus and rough endoplasmic reticulum arranged either in spirals or in concentric circles throughout the cytoplasm of the cell. They also had the well-developed Golgi complex and long mitochondria with flat and transverse cristae. The Golgi complex was similar to microvesicular cluster, but usually in the shape of typical dictyosomes, These features of androgenic gland cells coincides well with the protein/peptide secretion in their function. However, despite the apparent ultastructual equipment for protein/peptide secretion, no accumulation of materials secreted were noticed in the cytoplasm. Therefore it is strongly suggested that the transient transportation of the materials into the hemocoel has occurred just after synthesis.

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The Predilution Effect of Al-based Liquid Coagulants for the Optimal Efficacy (최적 응집 효율을 위한 Al계 액상 응집제의 희석 효과)

  • Heo, Jae-Yong;Lee, Sang-Wha
    • Applied Chemistry for Engineering
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    • v.17 no.1
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    • pp.37-43
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    • 2006
  • The coagulation efficacy of Al-based coagulants (such as Alum, PACS, and PACC) was investigated to ascertain removal efficiencies of turbidity and phosphate with variation of solution pH, coagulant dosages, and pre-dilution ratios. The efficacy of Al-based coagulants was maximized in the pH range of 6~9. Under the initial condition of pH 8, $10mg/L\;{PO_4}^{3-}$, and 20 NTU, Al-based coagulants exhibited a similar efficacy in the removal of turbidity, whereas the removal efficiency of phosphate was clearly dependent on the basicity of coagulants: Alum (0%) > PACS (45~50%) > PACC (70%). At high initial turbidity of 100 NTU, polymeric coagulants, such as PACS and PACC, exhibited a higher removal efficiency of turbidity compared to Alum. In comparison to direct injection of coagulants at low initial turbidity (20 NTU), 500~2000 times pre-diluted Alum, exhibited reduced coagulation efficacy; however, removal efficiencies of turbidity and phosphate increased with the increase of retention time. Pres-diluted PACC exhibited the enhanced coagulation efficacy followed by silght decrease of the removal efficiencies with increase of the retention time. At high initial turbidity of 100 NTU, pre-diluted Alum and PACC exhibited higher removal efficiencies of turbidity and phosphate.

Finite Element Stress Analysis of Bone Tissue According to the Implant Connection Type (2종의 임플란트 내부결합구조체에 따른 치조골상 유한요소응력 분석)

  • Byun, Ook;Jung, Da-Un;Han, In-Hae;Kim, Seong-Ryang;Lee, Chang-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.29 no.3
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    • pp.259-271
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    • 2013
  • The purpose of this study was to make the stress distribution produced by simulated different load under two types of internal connection implant system (stepped and tapered type) by means of 3D finite element analysis, The finite element model was designed with the parallel placement of the one fixtures ($4.0mm{\times}11.5mm$) with reverse buttress thread on the mandibular 1st molar. Two models were loaded with 200 N magnitude in the vertical direction on the central position of the crown, the 1.5 mm and 3 mm buccal offset point from the central position of the fixture. The oblique load was applied at the angle of $30^{\circ}$ on the crown surface. Von Mises stress value was recorded and compared in the fixture-bone interface in the bucco-lingual dimension. The results were as follows; 1. The loading conditions of two internal connection implant systems (stepped and tapered type) were the main factor affecting the equivalent bone strain, followed by the type of internal connections. 2. The stepped model had more mechanical stability with the reduced max. stress compared to $11^{\circ}$ tapered models under the distributed oblique loading. 3. The more the contact of implant-abutment interface to the inner wall of implant fixture, the less stress concentration was reduced.