• Journal of the Korean Geotechnical Society
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• v.38 no.5
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• pp.35-46
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• 2022

The in-situ resource utilization (ISRU) for sustainable lunar surface and deep space explorations has recently gained attention. Also, research on the development of construction material preparation technology using lunar regolith is in progress. Microwave sintering technology for construction material preparation does not require a binder and is energy efficient. This study applies microwave sintering technology to KLS-1, a Korean lunar simulant. It is crucial to secure the homogeneity to produce a sintered specimen for construction material. Therefore, understanding the interactions between microwaves, cavities, and raw materials is required. Using a numerical model in terms of efficient assessment of several cases and establishment of equipment operating conditions is a very efficient approach. Therefore, this study also proposes and verifies a coupled electric-thermal numerical model through cross-validation and comparison with experimental results. The numerical model proposed in this study will be used to present an efficient method for producing construction material using microwave sintering technology.

• Analytical Science and Technology
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• v.22 no.1
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• pp.101-108
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• 2009

The bioequivalence of two pioglitazone tablets, Actos$^{(R)}$ tablet (Takeda Chemical Industries, reference drug) and Pioglitazone tablet (Boryung Company, test drug) was evaluated according to the guidelines of Korea Food and Drug Administration. Twenty-eight healthy male Korean volunteers received each medicine (pioglitazone dose of 30 mg) in a $2{\times}2$ crossover study with one week washout interval. After drug administration, blood samples were collected at specific time intervals from 0-36 hours. The plasma concentrations of pioglitazone were determined by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total chromatographic run time was 5 min and calibration curves were linear over the concentration range of 5-2000 ng/mL for pioglitazone. The method was validated for selectivity, sensitivity, linearity, accuracy and precision. The pharmacokinetic parameters were determined from the plasma concentration-time profiles of both formulations. The primary calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two preparations. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Pioglitazone tablet and Actos$^{(R)}$ tablet were log0.9422~log1.1040 and log0.9200~log1.1556, respectively. Based on the statistical considerations, we can conclude that the test drug, Pioglitazone tablet was bioequivalent to the reference drug, Actos$^{(R)}$ tablet.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.317-324
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• 2020

In order to create the national food nutrient database, a total of 41 animal foods (ham, seafood, edible insects and eggs) were analyzed for their vitamin B₁₂ content and the applied immunoaffinity-HPLC was verified. Ham vitamin B₁₂ contents were 0.30-0.65 ㎍/100 g. Seafood showed relatively high vitamin B₁₂ level, where the values of fermented clam were the highest (26.80 ㎍/100 g) followed by fermented pollack roe. Vitamin B₁₂ was not detected in silkworm pupae and beetles, while relatively high levels were found in the two-spotted cricket imago (6.70 ㎍/100 g). Chicken and quail egg yolk had roughly 100- and 30-times higher vitamin B₁₂ levels as compared to their egg white. Vitamin B₁₂ contents in quail and chicken eggs were significantly enhanced by boiling (p<0.05). Results based on accuracy (97-102% recovery) and precision (<5% RSD) indicate that this study provides reliable vitamin B₁₂ information on animal foods consumed in Korea.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.1-9
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• 2015

As the use of software is more wider in the safety-critical nuclear fields, so study to improve safety and quality of the software has been actively carried out for more than the past decade. In the nuclear power plant, nuclear man-machine interface systems (MMIS) performs the function of the brain and neural networks of human and consists of fully digitalized equipments. Therefore, errors in the software for nuclear MMIS may occur an abnormal operation of nuclear power plant, can result in economic loss due to the consequential trip of the nuclear power plant. Verification and validation (V&V) is a software-engineering discipline that helps to build quality into software, and the nuclear industry has been defined by laws and regulations to implement and adhere to a through verification and validation activities along the software lifecycle. V&V is a collection of analysis and testing activities across the full lifecycle and complements the efforts of other quality-engineering functions. This study propose a methodology based on V&V activities and related tool-chain to improve quality for software in the nuclear power plant. The optimized methodology consists of a document evaluation, requirement traceability, source code review, and software testing. The proposed methodology has been applied and approved to the real MMIS project for Shin-Hanul units 1&2.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.697-708
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• 2016

As the needs for fast wireless communication technology in various fields, including companies, individuals, etc., grows, many research projects related to the coverage of propagation are being carried out for plaining optimized communication services. On the other hand, there are some limitations in surveying and analyzing propagation in highland areas. To provide a better communication service of a new service, a range of radio environment conditions based on a wide radio bandwidth (selection of propagation model, correction of value in accordance with radio bandwidth, etc.) should be considered. In particular, radio environment conditions are becoming increasingly sophisticated. By the early detection of real-time changes in the radio spectrum, which is based on an examination and research of regional occupied band width condition, proper measures should be established. To make a proper solution of above, the basic real-time analysis of spectrum distribution status by regional groups is necessary. In addition, the establishment of prompt measures should be enable by stored or analyzed radio data. In an attempt to predict reliable propagation coverage, this thesis examines the limited propagation data with HTZ Warfare, which were collected from domestic high land sites faced with limited access. Furthermore, a comparative result value evaluation for an optimized propagation model was performed through testing simulations, and frequency-dependent and propagation model-dependent analysis.

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.127-150
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• 2004

목포해양대학교 현행 4개 학부의 교육과정은 1997년도에 전면 개편되어 학부 단위로 무난히 실시되고 있지만, 해사계열의 특수성과 해양공학계열의 학부별 전공 구성의 차이점 등으로 인하여 일률적 학부운영방침을 대학 전체에 동일하게 적용하는 것은 다소무리가 있었다. 해양계 특성화라는 대학의 목표를 향하여 각 학부의 교육목표와 전공특성을 살리면서 사회와 관련산업계의 시대적인 요구를 만족시키기 위하여 학부운영을 효율화$\cdot$극대화할 수 있는 체제 정립 방안을 연구하고 있다. 1차 년도의 연구결과에 의하면, 해상운송시스템학부는 효율적인 학부운영체제의 개선 및 운영시스템 개발을 위하여 학부 특성 및 전공 구성에 대한 분석을 통하여 문제점을 발견하고 해결방안을 모색함과 동시에 학생들의 전공 선택권을 최대한 보장할 수 있는 효율적인 학부 운영 체제를 구축하는 방안을 제시한다. 기관시스템공학부는 현행 의무복수전공제도의 문제점 분석과 해결 방안 강구를 위하여 전공들간의 인계성을 강화하며 활성화할 수 있는 방안을 모색하고 해양경찰학 전공의 운영 및 지도 방안을 연구한다. 또한 해기품질관리 관련 규정 등의 분석을 통해 교육 및 훈련에 대한 질적 향상을 꾀하고 해기품질 향상을 위한 교육평가시스템을 개발하고 구축하고자 한다. 해양전자$\cdot$통신공학부는 전공간의 연계성 구축과 효율적 운영방안을 모색하기 위하여 학부제 및 복수전공제와 관련하여 설문조사 문항을 개발$\cdot$분석하고, 해양전자공학 전공 교과목 정비 및 교재 개발을 시도하고 있다. 해양시스템공학부는 전공구성의 특성을 고려한 탐색과목의 설치 및 산업체 실습과 연계한 학점인정과목의 검토를 위하여 현행의 전공소개 프로그램을 분석하고, 졸업생의 취업을 분석하며 산업체의 요구사항을 조사하고 있다.산 알고리즘의 정당성을 보였다. 맞이하고 있음을 볼 수 있다. 국내광업이 21C 급변하는 산업환경에 적응하여 생존하기 위해서는 각종 첨단산업에서 요구하는 소량 다품종의 원료광물을 적기에 공급 할 수 있는 전문화된 기술력을 하루속히 확보해야 하며, 이를 위해 고품위의 원료광물 확보를 위한 탐사 및 개발을 적극 추진하고 가공기술의 선진화를 위해 선진국과의 기술제휴 등 자원산업 글로벌화 정책이 절실히 요구되고 있음을 알 수 있다. 또한 삶의 질을 향상시키려는 현대인의 가치관에 부합하기 위해서는 각종 소비제품의 원료를 제공하는 광업의 본래 목적 이외에도 자연환경 훼손을 최소화하며 개발 할 수밖에 없는 구조적인 어려움에 직면할 수밖에 없다. 이처럼 국내광업이 안고 있는 여러 가지 난제들을 극복하기 위해서는 업계와 정부가 합심하여 국내광업 육성의 중요성을 재인식하고 새로운 마음가짐으로 관련 정책을 수립 일관성 있게 추진해 나가야 할 것으로 보인다.의 연구 결과를 요약하면 다음과 같다. 첫째, 브랜드 이미지와 서비스 품질과의 관계에서 브랜드이미지는 서비스 품질의 선행변수가 될 수 있음을 증명하였으며 4개 요인의 이미지 중 사풍이미지를 제외한 영업 이미지, 제품 이미지, 마케팅 이미지가 서비스 품질에 영향을 미치고 있음을 알 수 있다. 둘째, 지각된 서비스 품질과 가격 수용성과의 관계에서, 서비스 품질은 최소 가격에 신뢰서비스 요인에서 정의 영향을 미치고 있으나 부가서비스, 환경서비스에서는 역의 영향을 미침을 알수 있고, 최대 가격에 있어서는 욕구서비스 요인은 정의 영향을 미치지만 부가서비스의 경우에는 역의 영향을 미치고 있음을 알 수 있다. 셋째, 서비스품질과 재 방문 의도와의 관계에 있어서 서비스품질은 재 방문 의도에 영향을 미침을 알 수 있다. 따라서 브랜드 이미지는 서비스품질의 선행변수가 될 수 있으며, 서비스품

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1497-1502
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• 2013

When using hydrogen gas as an ecofriendly energy sources, it is necessary to conduct a safety assessment and ensure thereliability of the hydrogen pressure vessel against hydrogen embrittlement expected in the steel materials. In this study, by applying the in-situ SP test method, the gas hydrogen embrittlement behaviors in SA372 steel, which is commonly used as a pressurized hydrogen gas storage container, were evaluated. To investigate the hydrogen embrittlement behavior, SP tests at different punch velocities were conducted for specimens with differently fabricated surfaces at atmospheric pressure and under high-pressure hydrogen gas conditions. As a result, the SA372 steel showed significant hydrogen embrittlement under pressurized hydrogen gas conditions. The effect of punch velocity on the hydrogen embrittlement appeared clearly; the lower punch velocity case indicated significant hydrogen embrittlement resulting in lower SP energy. The fractographic morphologies observed after SP test also revealed the hydrogen embrittlement behavior corresponding to the punch velocity adopted. Under this pressurized gas hydrogen test condition, the influence of specimen surface condition on the extent of hydrogen embrittlement could not be determined clearly.

• The Journal of Korean Association of Computer Education
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• v.23 no.4
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• pp.23-33
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• 2020

Online judge provides compilation, execution, and immediate feedback on the source submitted by the learner, and ensures the accuracy and reliability of the evaluation, but it's difficult to select the language according to the level of the learner because most of them provide only textual language. In this study, a block language for online judge was developed and applied to high school classes, and the difference in self-efficacy between the block language and the textual language group was confirmed. It was found that Block language group have more ability expectation to overcome disgust experience than textual language group and Textual language group have significant decrease in ability expectation to start activity and to continue activity. It implies that Block language has an effect on self-efficacy for afterward programming activities, and methods of teaching, learning and evaluation should be devised in the case of textual language so that student's self-efficacy does not deteriorate at the initial and ongoing stage of activity. The results of this study are meaningful in that it provide various implications of methods for enhancing self-efficacy in high school class of programming.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.3
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• pp.37-42
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• 2022

Recently, the semiconductor package structures are becoming thinner and more complex. As the thickness decrease, interfacial delamination due to material mismatch can be further maximized, so the reliability of interface is a critical issue in industry field. Especially, the polymers, which are widely used in semiconductor packaging, are significantly affected by the temperature and moisture. Therefore, in this study, the delamination prediction at the interface of package structure was performed through finite element analysis considering the moisture absorption and desorption under the various temperature conditions. The material properties such as diffusivity and saturated moisture content were obtained from moisture absorption test. The hygro-swelling coefficients of each material were analyzed through TMA and TGA after the moisture absorption. The micro-shear test was conducted to evaluate the adhesion strength of each interface at various temperatures considering the moisture effect. The finite element analysis of interfacial delamination was performed that considers both deformation due to temperature and moisture absorption. Consequently, the interfacial delamination was successfully predicted in consideration of the in-situ moisture desorption and temperature behavior during the reflow process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.102-113
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• 2013

The purpose of this study was to examine parental perceptions on the importance, performance level, and satisfaction with foodservice quality at daycare centers in the Compensation and Welfare Service institute. The questionnaire was developed to measure thirty-two attributes of foodservice operations are administered to 598 parents and 23 foodservice supervisors from June 22, 2009 to July 10, 2009. The parents placed a high importance on the need for foodservices, earning 4.70 points out of 5 points. Their perceptions of foodservice quality menu, foodservice ingredients and effects, facilities, sanitation, and service scored even higher than performance. The overall satisfaction level for foodservice compared to performance was 4.33 and 4.03 points out of 5 points, respectively. Multiple regression analysis indicated that 98.6% of the variance in parents' overall satisfaction scores was explained by six dimensions.