• Archives of Reconstructive Microsurgery
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• v.14 no.2
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• pp.95-104
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• 2005

The aim of this study was to investigate the major vascular system to supply flap, flap survival rate and complications after flap elevation in order to evaluate possibility of the vascularized face/scalp allotransplantation. Forty New Zealand white rabbits were divided into two groups: control group and experimental group. Individuals of control group had a face/scalp composite unit which was composed of skin, subcutaneous tissue and platysma muscle, supplying by bilateral facial artery, temporal artery and auricular artery and draining by external jugular vein. After a flap was elevated, bilateral facial artery, temporal artery and auricular artery were ligated. On the other hand, those of experimental group had the same composite unit as control group with bilateral facial artery, temporal artery and auricular artery being not ligated. We had measured survival area of flaps of the sixteen individuals survived for four weeks in the control group and fourteen in the experimental group by Grid method. The mean survival durations of the flap were 3.7days in the control group, 20.0days in the experimental group. The significant differences in the mean survival durations and survival rate at the 28days were found between the control and experimental group (p<0.05). Mean values about the survival area's fractions of all were $1.3{\pm}4.%$ in the control group and $63.1{\pm}4.8%$ in the experimental group. Those of experimental group was significantly higher than control group statistically (p<0.05). The composite face/scalp flap which we have elevated, supplied by bilateral facial artery, temporal artery, auricular artery and drained by external jugular vein has flap viability enough to be transplanted after its elevation.

• Journal of the Korean Society for Library and Information Science
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• v.16
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• pp.71-110
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• 1989

The purpose of this study is to investigate the influential factors creating the modern library thought in the latter part of Yi Dynasty. After Korea was forced to make a treaty opening up the country in 1876, Western civilization was introduced and reforms were carried out eventually. Various influential factors could be taken into consideration as follows. (1) The envoys to Japan after 1876 (2) Tourists party to Japan organized by Gentlemen in 1982 (3) The persons who studied abroad (4) Establishment of modern schools and development of publications: on the new learning. (5) News media and others Above all, the persons who studied abroad, such as Yu Gil Jun, Yun Chi Ho, etc., in early stage has contributed most to the extension of public recognition for modern library in Korea. Therefore it can be said that the formation of modern library thought in Korea was based on the theory of the Western library as was the Japan in the period of Meiji Restoration. Patriotic intelectualls in these days believed that reform of the educational system and the diffusion of knowledge was very much meeded in order to preserve an independent Korea and to build up national strength, and then nation-wide campaign for enlightenment was earried on. For that reason the movement of the national library establishment in 1906 also should be regarded from the same point of view, that is, as a part of the enlightenment campaign. Therefore it should not go unheeded that strong patriotism was always streamed under the ground of the library campaign as well as the new learning and new education campaign. Unfortunately every plan of Korean library movement had broken down and missed the chance for having experience of self-development because of the Japanese invasion.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.225-234
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• 2005

The purpose of this study was to examine the causes of bakery employees quitting their jobs at hotels in order to make more efficient use of human resources by increasing personnel management efficiency and reducing the turnover rate, The subjects in this study were employees working for bakeries at top-ranked hotels, and the responses from 266 respondents were selected for analysis. The survey was conducted from July 1 through 20, 2003. Frequency analysis, factor analysis, reliability analysis, t-test, ANOVA and regression analysis were performed for data handling. The major findings of this study were as follows: First, concerning salaries, their turnover intention was influenced by whether they were properly paid or gained a sufficient living. Second, as for environmental factors, their turnover intention was affected by performance appraisal and interpersonal trust with colleagues. Third, regarding job-related factors, their turnover intention was impacted by the clarity of their job definition, their degree of job satisfaction and the suitability of their posts. Fourth, the change of job was influenced by the desire for a job in another region, in another company and of another kind. To successfully manage employee turnover at hotel bakeries, employees should be properly paid, and different performance appraisal standards, including a multilateral evaluation system, should be applied according to the nature of the department. furthermore, there should be a clear distinction between sales and other works, and they should be carefully treated to increase job satisfaction.

• Journal of Life Science
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• v.7 no.4
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• pp.253-261
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• 1997

In order to enhance glutathione production, various recombinant plasmids containing gshI and/or gshII genes isolated from E. coli K-12 were constructed and introduced into E. coli. Some plasmids contained one to three copies of gshI genes in pBR325 and others contained both gshI and genes for glutathione biosynthesis. $\gamma$-Glutamylcysteine synthetase activities of E, coli strains amplified tandem repeated gshI genes were dependent on the number of inserted gshI genes. The glutathione productivity of E. coli strains harboring various plasmids was investigated using an E. coli acetate kinase reaction as an ATP regenerating system. The glutathione productivity of E. coli strains harboring tandem repeated gshI genes was increased in proportion to the number of inserted gshI genes. By the introduction of gshII gene, the glutathione productivity of the E. coli was increased by two-fold compared with E. coli strain amplified gshI gene only. The enzymatic production of glytathione in E. coli was mainly affected by the increase of $\gamma$-glutamylcysteine synthetase activity. The highest glutathione productivity was obtained in E. coli strains harboring pGH-501 plasmid containing two copies of gshI and copy of gshII genes in pUC8 vector.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3327-3335
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• 2014

In this study, comparison works have been performed for single-stage and multi-stage refrigeration cycle using propane as a refrigerant in order to cool down the natural gas stream. A comparative analysis has been performed for a single, two, three and four stage refrigeration cycle using propane as a refrigerant for cooling the natural gas stream. For the simulation, natural gas feedstock properties supplied by KOGAS were utilized and Peng-Robinson equation of state model was used. As the number of compression stages increase, the condenser heat duty is decreased. The refrigeration heat duty for a four-stage refrigeration cycle is decreased by 20.36% compared to that for a single-stage refrigeration cycle. Moreover, the total refrigerant circulation rate for a four-stage refrigeration system is was reduced by 14.53% compared to the single stage refrigeration cycle. The total compression power for a four-stage compression was reduced by 41.61% compared to the single stage compression.

• Journal of the Korea Computer Industry Society
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• v.6 no.3
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• pp.495-508
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• 2005

Moving objects are spatiotemporal data that change their location or shape continuously over time. Their location coordinates are periodically measured and stored i3l the application systems. The linear function is mainly used to estimate the location information that is not in the system at the query time point. However, a new method is needed to improve uncertainties of the location representation, because the location estimation by linear function induces the estimation error. This paper proposes an application method of the cubic spline interpolation in order to reduce deviation of the location estimation by linear function. First, we define location information of the moving object on the two-dimensional space. Next, we apply the cubic spline interpolation to location estimation of the proposed data model and describe algorithm of the estimation operation. Finally, the precision of this estimation operation model is experimented. The experimentation comes out more accurate results than the method by linear function.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.444-455
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• 2009

The selective central curriculum, which has been applied to the grades eleven and twelve in the 7th curriculum, has not operated well due to lack of teacher supply. This study analyzes the needs for the contents which are necessary to operate the minority optional curriculum through cyber education. Based on the developed contents, pilot program was performed. As a result of the program, the learning progress ratio of students was high but their satisfaction was very low. It is suggested that the quantity of the content should be reduced and the degree of difficulty lowered in order to address the problems. Another suggestion is to provide students with on-line teachers such as learning planners, tutors, and consultations to systematically manage students' learning. In addition, various elective-courses should be developed to allow students to take the courses of their choice, which in turn requires the establishment of the national operation system for the minority optional curriculum.

• Journal of the Korean Institute of Gas
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• v.2 no.1
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• pp.14-22
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• 1998

In this work, in order to quantitatively predict the radiation flux and propose an idea about how to reduce the radiation damage, the radiation flux caused by pool fire of an LNG storage tank has been calculated using the RISC (Risk and Industrial Safety Consultant) proposed model under various conditions. Model predictions showed that the most important parameter affecting the radiation flux by the LNG pool fire is the wind speed. The extent of radiation damage to a target from fire flame was more significant with variation of wind speed at a low wind speed than with that at a high wind speed. It was found that the radiation damage by the former is substantially reduced with planting windbreak system around the plant. Since the windbreak is most economical than any other method, it is strongly suggested to plant a tree belt in the factory surroundings, especially near by the area of gas storage facilities, linking with water cooling and fire protection systems.

• Steel and Composite Structures
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• v.25 no.6
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• pp.663-670
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• 2017

The problem of layup optimization of the composite laminates involves a very complex multidimensional solution space which is usually non-exhaustively explored using different heuristic computational methods such as genetic algorithms (GA). To ensure the convergence to the global optimum of the applied heuristic during the optimization process it is necessary to evaluate a lot of layup configurations. As a consequence the analysis of an individual layup configuration should be fast enough to maintain the convergence time range to an acceptable level. On the other hand the mechanical behavior analysis of composite laminates for any geometry and boundary condition is very convoluted and is performed by computational expensive numerical tools such as finite element analysis (FEA). In this respect some studies propose very fast FEA models used in layup optimization. However, the lower bound of the execution time of FEA models is determined by the global linear system solving which in some complex applications can be unacceptable. Moreover, in some situation it may be highly preferred to decrease the optimization time with the cost of a small reduction in the analysis accuracy. In this paper we explore some machine learning techniques in order to estimate the failure of a layup configuration. The estimated response can be qualitative (the configuration fails or not) or quantitative (the value of the failure factor). The procedure consists of generating a population of random observations (configurations) spread across solution space and evaluating using a FEA model. The machine learning method is then trained using this population and the trained model is then used to estimate failure in the optimization process. The results obtained are very promising as illustrated with an example where the misclassification rate of the qualitative response is smaller than 2%.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.137-143
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• 2011

Epoxy resins are widely used as high performance thermosets in many industrial applications, such as coatings, adhesives and composites. Recently, a lot of research has been carried out in order to improve their mechanical properties and thermal stability in various fields. Carbon nanotubes possess high physical and mechanical properties that are considered to be ideal reinforcing materials in composites. CNT-reinforced epoxy system hold the promise of delivering superior composite materials with their high strength, light weight and multi functional features. Therefore, this study used multi-walled carbon nanotubes (MWNT) and gamma rays to improve the mechanical and thermal properties of epoxy. The diglycidyl ether of bisphenol A (DGEBA) as epoxy resins were cured by gamma ray irradiation with well-dispersed MWNTs as a reinforcing agent and triarylsulfonium hexafluoroantimonate (TASHFA) as an initiator. The flexural modulus was measured by UTM (universal testing machine). At this point, the flexural modulus factor exhibits an upper limit at 0.1 wt% MWNT. The thermal properties had improved by increasing the content of MWNT in the result of TGA (thermogravimetric analysis). However, they were decreased with increasing the radiation dose. The change of glass transition temperature by the radiation dose was characterized by DMA (dynamic mechanical analysis).