• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.1
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• pp.51-56
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• 2007

Flow characteristics in a liquid fuel ramjet combustor were investigated using the PIV method. The combustor has two rectangular inlets that form a $90^{\circ}$ angle each other. Three cases of test combustors are made in which those inlet angles are $30^{\circ},\;45^{\circ}\;and\;60^{\circ}$. The experiments were performed in a water tunnel test with the same Reynolds number as Mach 0.3 at the inlet. PIV software was developed to measure the characteristics of the flow field in the combustor. A large and complex recirculating flow was measured in the dome area with 4 different dome size. Experimental results shows that 1/3 dome size of combustor diameter is suitable and smaller inlet angle provide large recirculation flow at the dome of combustor as a frame holder in this experimental ranges but need to consider secondary recirculation flow in a junction region to optimize the configuration of ramjet combustor.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.1052-1056
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• 2011

이 연구는 동위원소실에 근무하는 임상병리사들의 방사선 방어에 대한 지식, 태도 및 행위수준을 조사하여 상관관계를 파악하고 방사선 안전관리에 대한 행위에 영향을 미치는 요인을 분석하기 위해 시행하였다. 설문지는 2010년 10월부터 11월까지 대전 충청권 및 서울 경기권 동위원소실 임상병리사를 연구 대상자로 하여 연구자자 임의로 선정 직접설문, 또는 우편방식으로 조사하였고, 수집된 자료는 SPSS12.0 프로그램을 이용하여 빈도와 백분율, T-검정, ANOVA, 다중회귀분석법을 이용하여 분석하였다. 방사선 안전관리에 대한 지식 점수는 평균은 11.5점이었으며 표준편차는 ${\pm}$1.9 분포를 보였다. 방사선 안전관리에 대한 태도 점수는 평균 69.0점, 표준편차는 ${\pm}$5.4이었다. 방사선 방어에 대한 행위점수는 평균은 57.1점, 표준편차 ${\pm}$3.5이었다. 방사선 안전관리 행위에 있어 이론적으로 알고 있는 내용에 비해 수행이 현저히 떨어진 결과가 나왔으며, 방사선 안전관리에 대한 지식, 태도, 행위와의 상관성은 통계적으로 유의한 상관관계를 보였다(p<0.01). 행위점수에 영향을 미치는 요인으로는 종사자법정교육, RI 면허취득, 지식, 태도로 나타났다. 결론적으로 동위원소실에 근무하는 임상병리사의 방사성동위원소 안전관리 행위는 태도에 비하여 수행이 현저히 떨어진 결과가 나왔고, 안전관리 행위에 영향을 주는 인자로 종사자법정교육, RI 면허취득, 지식점수, 태도점수를 알 수 있었다. 업무 진행에 있어 잘못된 지식의 습득 및 태도를 취할 수 있는 가능성이 충분히 있으며 이를 바로 잡을 수 있도록 안전관리에 대한 지속적인 교육을 실시함과 더불어 RI면허 취득, 방사선 종사자에게 교육의 효과를 더욱 높이기 위한 적절한 교육 자료의 개발이 필요하다고 할 수 있다.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.25-28
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• 2008

Currently, the prefabricated bridge having the effects to reduce the term of works and the cost of construction is often studied and countries such as America have already developed members, the parts of it, and the technique of construction. In addition, they have supplied them to the fields. The study of prefabricated method of steel composite bridge, which has the precast deck - plate and main girder fixed by high tension bolt and can resist horizontal sheer, is being progressed. However, it is difficult to understand the characteristics of the prefabricated bridge's behavior when the superstructure of the prefabricated method is analyzed by applying to the analysis model of existing bridges. Therefore, this study has the purpose of understanding real structural behavior of prefabricated bridge through comparison and analysis between the structural analysis model reflecting the characteristics of the real prefabricated bridge's superstructure and real size experiment.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.333-340
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• 1994

Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16 MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with two complete blood count analyzers (Sysmex WE-8000 and Coulter STKS) for unidirectional data transmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.2
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• pp.122-129
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• 2019

Predicting heat transfer from the inner wall of the combustion chamber of the liquid rocket is a very difficult task. Several complex processes, such as convection, radiation and conduction must be taken into consideration. Usually commercial programs are used for the analysis of this processes. However, commercial programs are not a perfect solution, because of the long calculation times and a burdening data-input work. In this study, we developed and implemented one - dimensional thermal analysis. This technique can be easily used on the initial stage. The design of the combustion chamber's cooling channel of the steam generator designed using developed technique. In order to compare experimental and theoretical data, the combustion test was performed. Obtained experimental data for the coolant temperature differ from the theoretical prediction by only 8.5%.

• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1311-1317
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• 2018

The ultimate goal of satellite development is to use information obtained from satellites. Therefore, national-levelsatellite development program should include not only hardware development, but also infrastructure establishment and application technology development for information utilization. Until now, Korea has developed various satellites and has been very useful in weather and maritime surveillance as well as various disasters. In particular, KOMPSAT (Korea Multi-purpose Satellite) images have been used extensively in agriculture, forestry and marine fields based on high spatial resolution, and has been widely used in research related to precision mapping and change detection. This special issue aims to introduce a variety of recent studies conducted using KOMPSAT optical and SAR (Synthetic Aperture Radar) images and to disseminate related satellite image application technologies to the public sector.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.1
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• pp.31-36
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• 2019

As the number of elderly population increases, the proportion of edentulous patients is increasing, and the demand for traditional dentures will also increase. Arranging the artificial teeth according to the relationship and shape of the upper and lower alveolar ridge is an important factor increasing the stability of the denture. This case is a 79 year old female patient who wishes to make denture covered by national health insurance for psychological and economical reasons. With the alveolar bone severely atrophic, the dental CAD software was used for accurate diagnosis and the posterior teeth were arranged in a cross bite according to the interalveolar crest line angle by the program. After completion, the denture showed adequate stability and maintenance in periodic examinations and treatment, and the patient also expressed high satisfaction.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.516-526
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• 2016

This paper introduces a hovering-type autonomous underwater vehicle (AUV) developed for research and its fundamental motion performance results obtained by simulation and field test. The AUV can control its motion in four degrees of freedom (DOF) by means of its horizontal and vertical thrusters, and it is designed to provide a test-bed that facilitates ease of operation and experimentation. Prior to the field tests, six DOF equations of motion are developed, and a simulation program is constructed using MATLAB and Simulink to verify the essential motion performance of the designed vehicle. Furthermore, a proportional-integral-derivative (PID) controller and fuzzy PID controller are designed, and their performances are verified through a simulation. Field tests are performed to verify the motion performance of the AUV; way-point tracking is executed by the PID and fuzzy PID controllers. The results confirmed appropriate control performance under current disturbances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.465-473
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• 2018

A cabinet-door integrated finite element model for a built-in side-by-side refrigerator with an ice dispenser and home bar was constructed, and its deformation was analyzed by ANSYS. As loads, the food load in the shelf and baskets, and thermal load occurring during the normal operation condition were considered. From results of the analyses, the door height difference (DHD) and door flatness difference (DFD) between the two doors, and the increase in the gap of the door gasket, which affects the sealing of cool air in the cabinet, were derived. As results of an evaluation of the differences, the DHD and DFD under the assembled condition satisfied the acceptance criteria of the manufacturer. The food and thermal loads increased the DHD and DFD due to thermal deformation, and the DFD increased significantly. In addition, the increase in the gap of door gasket located between the cabinet and doors was derived from the results of displacements under the food and thermal loads. The evaluation showed that the maximum increase in gap appeared at the left edge of the freezing compartment gasket, which satisfied the acceptance criteria of the manufacturer.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.537-547
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• 2017

This study attempted to determine differences between the perceived empowerment level and job satisfaction depending on hairdressers' demographic characteristics and analyze the effects of their empowerment on job satisfaction. For this, a total of 310 hairdressers in Gwangju-Jeonnam and Seoul-Gyeonggi-do were chosen through convenience sampling, and then a questionnaire survey was conducted. The valid 277 copies were used for final analysis. For data analysis, descriptive statistics, factor analysis, reliability analysis, t-test, ANOVA, Duncan's test, and multiple regression analysis were conducted using SPSS 15.0. The study results found the following: First, in terms of the subordinate factors of empowerment, the following four factors were found: meaningfulness, self-determination, competence, and impact. Second, depending on demographic characteristics (e.g., age, career, type of beauty salon, job title, punch-in time, monthly pay), a statistically significant difference was found between empowerment and job satisfaction (p<.01). Third, hairdressers' perceived empowerment level had a positive impact on job satisfaction (p<.01). In terms of the empowerment on job satisfaction by sub-factor, 'self-determination' was largest, followed by 'meaningfulness' and 'competence.' Therefore, beauty salon owners need to manage their business more efficiently by converging cosmetology and business management by expanding empowerment among hairdressers properly after recognizing the importance of hairdresser empowerment.