• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.35-38
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• 2005

The computational fluid dynamic analysis has been conducted for the thermo-chemical flow field in an arcjet thruster with mono-propellant hydrazine ($N_{2}H_4$) as a working fluid. Coupled Reynolds Averaged Navier-Stokes (RANS) equations and Maxwell equations were used to account for the Ohm heating and Lorentz forces. Hydrazine chemistry and thermal radiation were also incorporated to the fluid dynamic equations by assuming infinitely-fast reactions and optically thick media. In addition to the thermo-physical understandings of the flow field inside the arcjet thruster, results shows that performance indices are improved by amount of $20\%$ in thrust and $200\%$ in specific impulse with the 0.6kW are heating.

• Korean Journal of Head & Neck Oncology
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• v.16 no.1
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• pp.37-41
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• 2000

Background and Objectives: The most commonly used incision for parotidectomy is modified Blair incision, but it has unsatisfactory cosmetic result due to long exposed scar in the neck. Therefore, we introduce an alternative approach with more acceptable scar named modified facelift incision. We report it's techniques, indications and disadvantages with our experiences. Materials and Methods: During the 1999, 15 patients were underwent parotidectomies using modified facelift incision. We studied the postoperative complications and the cosmetic results respectively. Results: There were 11 benign tumors, 3 malignant tumors, and 1 chronic inflammation. Total parotidectomy was performed in 2 malignant tumors and chronic parotitis patients. The others has superficial parotidectomy. In terms of operation field, there was no difference between classical incision and facelift incision. Partial facial nerve palsy was noted in 2 cases, who required sacrifice of branches of facial nerve because of malignant tumor invasion. There were no specific complications associated with this type of approach. Postoperative cosmetic results were satisfactory in all cases. Conclusion: Modified facelift incision provides better cosmetic result than conventional incision without narrowing of operation field. We believe that it is a safe alternative approach to all parotidectomy cases especially to women and patient with keloid skin. The only limitation of this incision is poor adaptability for combining neck dissection.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.187-191
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• 2003

The motion and time-mean drift force of a 2-D floating BBDB in waves are studied with and without taking account of fluctuating air pressure in the air chamber. It has been found numerically that the drift for a of the BBDB is in the reverse direction of propagation of the incident waves over specific frequency ranges as found by McCormick through his experiment work. The drift force is calculated by Pinkster's near-field method. Since Maruo's formula method for the drift force is always positive, Maruo's formula is only approximate and should be replaced by the correct near-field method.

• Journal of the Korean housing association
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• v.21 no.6
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• pp.119-129
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• 2010

The purpose of this study was to identify perception on housing welfare of social welfare practitioners. Specific research interest was focused on the area of housing welfare services and necessity, problems when execute housing welfare services, and activating strategy of housing welfare. For the research purpose, questionnaires were distributed to 537 people who work in the field of social welfare including social welfare officials in local government authorities and social workers at community welfare centers nationwide by mail and e-mail and 405 questionnaires were analyzed using SPSS 15.0 program. Respondents thought that the supply of public rental housing was the most important service to promote housing welfare. They also indicated the most serious problem was the lack of budget and housing welfare services and programs. As main reasons of local government's passive attitude toward housing welfare services and programs, respondents mentioned low interest level of housing welfare and lack of housing welfare education. Most of the respondents agreed the necessity of introducing the curricula related to housing welfare and expected to spread interest toward housing welfare in the field of social welfare.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.143-151
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• 2012

The facility safety management in Korea does not secure efficiency as a safety management that is not constructed a maintenance manual. As such, disaster dangerous facilities are at a great danger for disaster occurrence. Accordingly, this study introduced revised requirement and revised level of requirement to field attendants to explore domestic facility safety management system, and set up and suggested a revised plan through brainstorming and attendants of central management institutions. This study is of importance that it reflects field attendants and attendants of central management institutions, suggests specific alternatives for realization to improve national level of institutional improvement.

• Journal of Environmental Impact Assessment
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• v.15 no.5
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• pp.289-297
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• 2006

The study investigates the problems of silt protector used for mitigation measure of suspended sediments (SS) during coastal construction and provides their improvements based on the field investigation and analysis of the environmental impact assessment reports for the coastal development projects of Korea. The field investigation along west, east and south coasts of Korea reveals a variety of problems in the installation and management of silt protector solely used for the SS mitigation in Korea. Major problems include installation itself, low cost and quality of silt protector, and maintenance. These problems superimpose the effectiveness of silt protector in mitigating coastal environment impact. The present study provides the specific guideline on the project type needed for the installation of silt protector, installation standard and planning, maintenance and management. The study also suggests new mitigation options such as environmental window to limit the construction period and environmental dredger to compensate for the deficits of silt protector.

• Journal of Sensor Science and Technology
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• v.29 no.2
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• pp.105-111
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• 2020

Interest and demand for hydrogen sensors are increasing in the field of H₂ leakage detection during storage/transport/use and detection of H₂ dissolved in transformer oil for safety issues as well as in the field of breath analysis for non-invasively diagnosing a number of disease states for a healthy life. In this study, various ZnO-based sensors were synthesized by controlling the reduction in crystallite size, decoration of Pt nanoparticles, doping of electron donating atoms, and doping of various atoms with different ionic radii. The sensing response of the various prepared ZnO-based nanoparticles and quantum dots (QDs) for 10 ppm H₂ was investigated. Among the samples, the smallest-sized (3.5 nm) In³⁺-doped ZnO QDs showed the best sensing response, which is superior to those in previously reported hydrogen sensors based on semiconducting metal oxides. The higher sensing response of In-doped ZnO QDs is attributed to the synergic effects of the increased number of oxygen vacancies, higher optical band gap, and larger specific surface area.

• Journal of Agricultural Extension & Community Development
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• v.9 no.2
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• pp.147-160
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• 2002

Although the philosophy of sustainable community development does not give the cure-all solutions for the major problems faced in the communities, it is theoretically and practically recognized as a newly emerging paradigm toward community development theoretically and practically. However, more specific tasks and issues of sustainable community development remain unchallenged and descriptive statements. The main objective of this study was to find out the extensive community development practices through the review of current works in the area of sustainable community development indicator, local agenda 21 and the relative issues. The recommendations of this study were the following; 1) The sustainable community development indicators available in the community level should be selected. Also, how to integrate the objective condition and subjective perception in community development practices, and how to weigh the indicator item should be solved in order to compare and measure the implementation of community development works. 2) In relation to local agenda 21, how to secure the implementation mechanism is more important than the developing the local agenda 21. 3) The policies aimed to raise the resident's awareness, formation of community field, create community social capitals, and define strategies to the selective community development programs should be considered to make the philosophy of sustainable community development active in the field level.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.127-132
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• 2001

The purpose of this research is to compare and analyze scientific names and Korean names of interior plants, considering that consumes' purchasing systems consist of internet and communication media in the era of informationalization, to help the consumers purchasing plants, and to propose some directions for the unification of Korean name in practical circulation. This survey was performed during 4 months from May to September in 2000. The survey places for research were wholesale flower market of YangJje Dong and Nam Seoul. The used plants for research were 37 family, 76 genus and 120 species. The main methods of data collection were interview and reference f plants picture books. The main reference for identifying plant name was accomplished by Yoon Ypung-Sub's HORTUS KOREANA. The research results are as follows; 1) Fifty one plants were identified as using generic or specific name. 2) Thirteen plants were identified as using varietal name. 3) Twenty four plants were identified as using common name recoded in a plant dictionary. 4)Thirteen plants were identified as using incorrect name. Consequently, it was identified that the research for the unification of Korean name of interior landscape plants should be performed thorough continuous cooperation between academic field and business field for solving various problems which is occurred in plants circulation process.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.152-155
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• 2007

The object of this research is to evaluate the priority of R&B project alternatives which were already screened by both feasibility and suitability of technological performance. This research is a selection model for R&D project alternatives after setting phase. And it is designed by CHP model which include individual and mutual weights. This model have 5 steps. (1) Setting Technology-Modules derived on the setting phase (2) Presenting the evaluation standards divided with 'M-Field' and 'T-Field' (3) Assessing the evaluation standard and technology modules (4) Obtaining and integrating the individually and mutually effective weights (5) Selecting the technology modules based on the priority of order by CHP. Through these steps, this model can suggest the evaluation way from specific technology levels to project level. And it can be guaranteed to perform the selected module set.