• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.19-33
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• 2010

The surface film, which is formed on graphite negative electrodes during the initial charging, is a key component in lithium secondary batteries. The battery reactions are strongly affected by the nature of the surface film. It is thus very important to understand the physicochemical properties of the surface film. On the other hand, the surface film formation is a very complicated interfacial phenomenon occurring at the graphite/electrolyte interface. In studies on electrode surfaces in lithium secondary batteries, in-situ experimental techniques are very important because the surface film is highly reactive and unstable in the air. In this respect electrochemical atomic force microscopy (ECAFM) is a useful tool for direct visualizing electrode/solution interfaces at which various electrochemical reactions occur under potential control. In the present review, mechanism of surface film formation and its correlation with electrolyte are summarized on the basis of in-situ ECAFM studies for understanding of the nature of the surface film on graphite negative electrodes.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.192-200
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• 2003

The object of this research is to develop a computerized algorithm of cost estimation method to forecast the total construction cost in the bidding stage by the historical and elemental work cost data. Traditional cost models to prepare Bill of Quantities in the korea construction industry since 1970 are not helpful to forecast the project total cost in the bidding stage because the BOQ is always constant data according to the design factors of a particular project. On the contrary, statistical models can provide cost quicker and more reliable than traditional ones if the collected cost data are sufficient enough to analyze the trends of the variables. The estimation system considers non-deterministic methods which referred to as the 'Monte Carlo simulation. The method interprets cost data to generate a probabilistic distribution for total costs from the deficient elemental experience cost distribution.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.58-66
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• 2009

Recently, the BIM paradigm in domestic and foreign countries has been recognized as a momentum that can enhance productivity, efficiency, and collaboration of work in the construction industry. In this aspect, some countries have driven the development of BIM guideline to introduce and apply the Open BIM which is IFC-based BIM. Whereas, introduction and application of the BIM in Korea has been tried partly by several government agencies, public companies, design and construction companies. To promote the proliferation in the BIM use, therefore, the guideline needs to be developed first of all than anything else. In this context, this study addresses the trends of the BIM guidelines of foreign countries and strategic directions necessary for developing the Open BIM guideline.

• Applied Microscopy
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• v.20 no.1
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• pp.17-35
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• 1990

Effect of 5-hydroxytryptamine(5-HT, serotonin) and its precursor tryptophan on the cell proliferation of brain and somite parts of 4 day chick embryo in Dulbeco's modified essential medium was examined morphologically at cellular level. It was realized that the externally added 5-HT and/or tryptophan disturbed cell proliferation and severve necrosis occured. Electron micrograph showed that the development of cell organelles were greatly impaired. The activities of both acetylcholine esterase and $Mg^{2+}$ -dependent ATPase of the brain tissues of 5 day chick embryo, which received 1mg of tryptophan and/or 0.1mg of 5-HT at primitive streak stage after 24 hrs incubation of the fertilized egg, were much lower(about 20-25%) than those of control group. These results were supported by the electron micrographs of chemically treated cells. Control cells showed clear densed bands of acetylcholine esterase activity around nucleus and rough endoplasmic reticulum but tryptophan or 5-HT treated groups showed discontinued activity bands. In the case of $Mg^{2+}$-ATPase, the control groups showed clear continuous activity bands but tryptophan and/or 5-HT treated groups were discontinuous. From the previous and present studies, it seems that the intracelluar 5-HT level is very important for the cell proliferation and normal morphogenesis.

• Archives of design research
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• v.17 no.2
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• pp.261-268
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• 2004

The Colonial House is one of the most popular styles in America. The purpose of this study is to closely examine this style based on interior features classified by patterns and elements during America's colonial period. Results of this study show that the interior style of the Colonial House was, at first, similar to Europe style. It was then integrated into the Georgian style of England and affected by Palladio as time passed. The interior style of the American Colonial House was based on rationality and practicality in concern with American weather and regions rather than imitation. The side of the roof was clapboard and the windows arranged with symmetry and rules around the entrance hall. It was generally Palladian style and was decorated with classical details. Timber frame of the interior was based on log cabins that appeared early in the American immigration. Furniture styles such as Jacobian, Queen Ann and Chippendale were matched with unique wood-oriented details and folkways like Chest, Rush Chair and Windsor Chair The house was also decorated with pictures, mirrors and ornaments, etc.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.2
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• pp.103-123
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• 2006

Assuming that the knowledge creation and retrieval functions could be the most important factors for a successful knowledge management(KM) especially during the promotion stage of KM, this study suggests an e-learning application as one of best methods for producing knowledge and also the integrated knowledge repository model in which learning, knowledge. and information objects can be semantically associated through topic map-based knowledge map. The traditional KM system provides a simple directory-based knowledge map. which can not provide the semantic links between topics or objects. The proposed model can be utilized as a solution to solve the above-mentioned disadvantages of the traditional models. In order to collect the basic data for the proposed model, first, case studies utilizing interviews and surveys were conducted targeting at three Korean insurance companies' knowledge managers(or e-learning managers) and librarians. Second, the related studies and other topic map-based pilot systems were investigated.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.243-251
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• 2009

Changes in pH and acidity were investigated in kimchi containing different amounts of added onion and/or pear during fermentation at $10^{\circ}C$. As the fermentation period increase, the pH and sugar contents of the onion and/or pear kimchi were higher compared to the control kimchi. However, the acidity of the kimchi containing onion and/or pear was lower than that of the control. To enhance the acceptance of kimchi, the optimal conditions for the addition of onion and pear were evaluated with the central composite design, ANOVA, and response surface methodology. According to variations in the mixing ratio of onion and pear, smell, taste and overall acceptability differed significantly, but the appearance and texture were not different. The optimal levels of onion and pear, predicted on the basis of each corresponding sensory parameters for kimchi, were $4.55{\sim}5.00%$ and $0{\sim}0.30%$ for smell, 2.61% and 2.38% for taste and 2.78% and 2.57% for overall acceptability, respectively.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.183-192
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• 1993

A transmission electron microscopic study was performed to observe the ultrastructures of the male germinal cells and spermatozoa of Fibricola seoulensis. Spermatogonia were found in the periphery of the testis and characterized by large nuclei and comparatively little cytoplasms. Spermatocytes contained an oval to spherical nucleus. Their nuclear volume was little larger in comparative to that of cytoplasm, and the chromatin was comparatively little. The early spermatids were characterized by a great amount of cytoplasm, and numerous mitochondria encircled the nucleus. In a more advanced spermatids the electron-dense strands of chromatin appeared in the nucleus, and a pair of rootlet of the axoneme and a microtubule-organizing center (MTOC) were observed near the nucleus. The sectioned spermatozoa were found in the testis and the seminal vesicle. Their cross sectional views were divided into 6 types when they were distinguished on the basis of the morphology and components. The spermatozoa of F. seoulensis showed two flagella of 9+1 type axoneme.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.161-170
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• 2007

The purpose of this study is to find the solution that overcomes the existing assumption of symmetric cost functions in multi-class assignment. In the assignment problem, the assumption of a symmetric cost function means that the link cost is determined by each unique mode and is not affected by any other modes. In this study, the authors have applied a diagonalized algorithm and a heuristic model based on column generation to a multi-class assignment model and analyzed the result. Through the study, the authors found that the diagonalized algorithm produces equilibrium solutions by the initial convergence condition. In contrast to the diagonalized algorithm, the column generation algorithm has improved the solution model to overcome the problem of equilibrium solutions in the diagonalized algorithm.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1234-1238
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• 2005

우리나라의 수질오염에 대한 규제는 주로 호소 및 하천의 수질을 향상시키기 위하여 하수 및 공장폐수 등 점오염원을 중심으로 관리되어 왔으나 강우와 함께 대량 유출된 비점오염원은 수용하천의 자정능력을 감소시키고 있고 이로 인해 하천과 호소의 수질은 향상되지 못하고 있다. 또한, 농촌지역에서 배출되는 비점오염원은 정확한 기작의 분석이 안 되고 있으며, 비료$\cdot$농약의 사용 증가에 따라 영양염 및 유해물질에 의한 수질오염의 영향이 증가되고 있는 실정이다. 본 연구는 농촌지역의 강우-유출로 인한 비점오염물질의 유출특성 및 배출부하량을 조사하기 위하여 영산강권역의 외남천을 대상으로 조사하였다. 대상 유역의 토지용도 구분은 (1)논지역, (2)밭지역, (3)산지지역, (4)농촌주거지역, (5)복합지역(논, 산지)으로 구분하였다. 시료의 채취는 강우시 5회에 걸쳐 조사하였으며, 2L 용량의 무균채수병에 채취한 후, 아이스박스에 $4^{\circ}C$이하로 보관하여 24시간 이내로 실험실에 운반하여 실험하였으며, 매회 시료 채취 주기는 강우유출이 발생하기 전부터 강우 종료 후 유출량 변화가 없을 때까지 $9\~12$단계로 세분하여 유출량과 pH, DO, BOD, COD, SS, T-N, T-P의 농도를 측정하였다. 본 연구에서 조사한 결과 토지이용별 비점오염원의 SMC를 살펴보면 BOD의 SMC는 $4.38\~11.02mg/{\ell}$, COD의 SMC는 $7.07\~23.99mg/{\ell}$, T-N은 $1.57\~5.20mg/{\ell}$, T-P는 $0.11\~0.274mg/{\ell}$의 범위를 갖는 것으로 나타났으며, 전반적으로 논 지역에서 비교적 높게 나타났는데 이는 농작물의 경작에 따른 시비법의 영향으로 판단된다. 또한, 비점오염원의 유출특성을 보면 전반적으로 초기 오염물질 유출특성 갖는 것으로 나타났다.