• 한국해양공학회지
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• 제21권5호
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• pp.33-38
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• 2007

The welding methods have been applied in the most structural products from multi-field of automobile, ship construction and construction, and so on. The structure steel must have enough strength of structure. In this study, SS400 steel and STS304 steel were used to estimate the corrosion characteristics of the weld thermal cycle simulated HAZ. To evaluate the corrosion characteristics, also, the materials with two conditions were used in 3.5% NaCl. The one is to the drawing with diameter of ${\Phi}10$ and the other is to the residual stress removal treatment. The electrochemical polarization test and immersion test were carried out. From test results, corrosion potential, corrosion current density, weight loss ratio and corrosion rate were measured. In the kinds of SS400 steels, corrosion potential of weld thermal cycle simulated specimens after the heat treatment showed somewhat the direction of noble potential. And in the base metal to be drawing weight loss ratio and corrosion rate occurred higher than the other kinds. In the kinds of STS304 steels, the result of base metal to be drawing was similar to results of SS400 steels, too. Two kinds of $750^{\circ}C$ and $1300^{\circ}C$ of weld thermal cycle simulation after the heat treatment were rather higher than the other kinds in weight loss ratio and corrosion rate.

• 한국공간구조학회논문집
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• 제6권1호
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• pp.55-63
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• 2006

본 논문은 콘크리트 충전 원형 및 각형 합성 강관을 기둥부재로서의 적합성 및 적용성을 위한 연구로 두개의 강관을 합성한 콘크리트 충전 강관 기둥의 축압축 좌굴내력 및 변형형상에 대한 실험적 연구이다. 강관 기둥에 대한 연구는 콘크리트 충전 원형 강관 기둥, 콘크리트 충전 각형 강관 기둥, 콘크리트 충전 합성 강관 기둥으로 분류하여 실험을 수행하였다.

• 한국응급구조학회지
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• 제9권1호
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• pp.43-53
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• 2005

The purpose of this study was to survey a perception of frequency & importance level of job performance, from 249 paramedics who were working at fire station. The job related activities of 4 duties, 18 tasks and 145 task elements were checked by 4 rating scale. The data were analyzed using a SPSS program for descriptive statistics. The results of the study were as follows ; 1. Some of the most frequent tasks were medical tx, managing people & organization, trauma care, pt assessment, general coping skill 2. Some of the most frequent task elements were preparation of written reports, operation of pt lifting supplies, transportation of patients on stretchers, administration of cervical collar and utilization of scoop stretcher. 3. Some of the highest level of importance in task were resuscitation of circulation, surgical tx, safety & infection control, environmental emergency care, trauma care. 4. Some of the highest level of importance in task elements were administration of cervical collar, adult CPR, infant CPR, child CPR, and AED. 5. The highest level of task elements in perception of frequency & importance were administration of cervical collar, infection control after pt care, utilization of long back board, disinfection of ambulance after ride a long, care of chest pain pt, care of unconscious pt, tx of asthma. 6. A difference between frequent & importance score were due to lack of supplies(41%), structural problems(30%) and medical control system(16%), lack of skills(10%), Suggestion; 1. This paper would be more reliable and confirm through wilder range of survey. 2. It would be necessary of more depth survey through dacom study from paramedic. 3. Development of field oriented protocol & curriculum that based on task elements which have high score of both frequency & importance level is required.

• 공업화학
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• 제31권3호
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• pp.328-333
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• 2020

본 연구에서는 PFO와 Coal-tar의 구조와 열 중합 거동 분석을 통해 PFO와 Coal-tar으로 구성된 혼합 원료의 피치 합성 간 제조 특성을 확인하였다. 원소분석과 FT-IR 분석을 통해, PFO와 Coal-tar 각각 0.355, 0.818로 방향족화도 수치를 확인하였다. 또한, PFO와 Coal-tar의 열중량 분석을 통해 질량 감소곡선의 차이를 확인하였으며, 이러한 현상은 방향족 화도와 관능기 함량에 따른 구조적 안정성에 기인한 것으로 판단된다. 피치 제조 특성은 PFO를 원료로 사용한 피치가 혼합원료로부터 제조된 피치보다 평균적으로 낮은 수율과 높은 연화점을 보임을 확인하였다. 특히 유사한 연화점을 가지는 P360 (138.5 ℃)과 B420 (141.4 ℃)을 비교하였을 때, 두 피치의 탄화수율은 각각 29.89, 49.03 wt%로 Coal-tar가 혼합된 경우 약 20 wt% 향상됨을 확인하였다. 이러한 결과는 다량의 알킬기를 포함하여 높은 피치 중합 반응성을 가지는 PFO와 높은 열적 안정성을 가지는 Coal-tar의 혼합에 기인한 것으로 판단된다.

• 통상정보연구
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• 제10권2호
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• pp.325-348
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• 2008

The purpose of this study is to find out the relationship between job fitness, organizational justice(distributive, procedural, interactional), job satisfaction, organizational trust, organizational commitment, and voluntary turnover intention in private organization such as in small fire in Korea. To identify the these relationships, the secondary data or past studies that were related with job fitness, organizational justice, job satisfaction, organizational trust, organizational commitment, voluntary turnover intention was collected and theoretically arranged. I made the theoretical proposed model to explain these relationships between the constructs, identify the operational definitions and 18 hypotheses was established, there was executed the survey of 262 in employees. Using the collected data, previous performances to confirm the construct validity and internal consistency by EFA(Exploratory Factor Analysis); i.e. factor analysis by SPSS, reliability by cronbach's a, and by the CFA(Confirmative Factor Analysis) and structural equations modelling the proposed model was tested by LISREL v. 8.52. The research came to the conclusions as follows: First, three perceived justice had the positive effect to the job satisfaction empirically. Second, procedural justice in three perceived justice only had the positive effect to the organizational trust empirically. Third, distributive justice in three perceived justice only had the positive effect to the organizational commitment empirically. Forth, job fitness had the positive effect to the organizational commitment, organizational trust, job satisfaction empirically in perspective. Fifth, I found the relationship between job satisfaction and organizational commitment, between job satisfaction and organizational trust was positive, between organizational commitment and trust. Finally, job satisfaction, organizational trust had not the positive effect directly, but indirect effect via organizational commitment was identified in voluntary turnover intention by empirical test.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.71-74
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• 2007

With the changes of times the building materials tend to extend the demand for application under the special environment. Since high-ductile mortar is developed, the building materials show excellent performance like toughness, compression, tensile, and bending, etc. in the general concrete from the existing brittle point. And, recently they are widely used as repairing and reinforcing materials both at home and abroad because they are recognized as excellence like durability and fire-resistance. However, it is in a situation of creating problems in durability because it frequently happened deterioration of buildings that have already repaired and reinforced at a time when it requires reconstruction of recently deteriorated construction structure recently. Therefore, in this study improved with a more repair Material development and reinforcement of the second high-ductile mortar products for a variety of basic materials were presented want, research plans used include traditional repair materials and the newly developed PCM (polymer cement mortar) structural reinforcement type indicated that comparison. PCM analysis in order to present a rate depending on the types fiber 0, 1.2 and 2.0(%) at three levels and mixture water according to ratios of weight to Plain in the 2.0 and 1.85(kg) at two levels is set, the results were as follows. 1) This study has shown that PCM had excellent strain hardening behavior at the same time that the bending stress increased according to the fiber contents. 2) This study has shown that it had the durability performance due to the high substance transmission according to the fiber contents.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.425-428
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• 2006

In order to estimate the reduction of laodbearing capacity, followed by the attributive change of heat while high strength concrete structure is revealed on fire it is necessary to evaluate, it is necessary to evaluate the property of material under high temperature such as thermal conductivity, specific heat, compressive strength, modulus of rigidity and diminution figure. Therefore, this study is for the purpose of presenting evaluation data for the analysis of thermal behavior about the high strength concrete material under high temperature, through the experiment by manufacturing concrete(40, 50, 60, 80, 100 MPa) commonly used in the construction field. As a result of the study, in the case of physical attribute, it demonstrates a greater fluctuation of change than the one of 30 MPa concrete. In case of specific heat, the high strength concrete, shown the serious diminution between $500{\sim}600^{\circ}C$, presents the thermal change area corresponding to the change of high strength concrete. In compressive strength, regardless of intensity of concrete, all of them show the first intensity loss between normal temperature and $100^{\circ}C$, the dramatic loss beyond $400^{\circ}C$. The concrete weighing above 50 MPa shows a twice lower dramatic intensity loss than the one weighing $30{\sim}40MPa$. The concrete ranging from $60{\sim}80MPa$, shows the biggest diminution of modulus of elasticity under $400^{\circ}C$, which implies the structural unstability of temperature.

• Applied Microscopy
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• 제29권2호
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• pp.201-209
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• 1999

무당개구리 상처치유 과정 중 재생되는 피부 상피세포의 형태학적 특성을 관찰하기 위하여 투과전자현미경을 이용하였다. 상처유도 추 재형성과정 중의 표피는 재생되는 상피세포에 의해 $3\sim4$층을 형성하였으며, 세포들의 크기는 상충에서 하층으로 갈수록 크게 신장되어 있음이 관찰되었다. 세포 간격 또한 세포층의 기저부를 향할수록 넓어졌다. 기저층에 위치한 세포는 세포질 돌기들을 내어 데스모소옴이 형성되어 있었고, 원주형이었다. 기저막이 형성된 세포들 사이에는 원기세포들이 위치하고 있었으며, 이 세포들은 불규칙한 난형 또는 타원형으로 세포의 크기는 다른 세포들에 비해 작게 관찰되었다. 따라서, 상피조직은 재생될 때 원기세포들의 분열과 이동이 동반되어야 하므로, 무당개구리 상피는 시간이 경과함에 따라 정상조직과 동일하게 재생될 수 있을 것으로 생각된다. 본 연구에서 상처가 치유된 시점으로 확인된 31일 경의 상피조직의 관찰 결과 역시 추측했던 점과 일치되어 정상과 동일한 조직학적 구성을 이루고 있었다. 또한 재형성 과정 중 상피는 피부가 정상조직으로 형성되기 전까지 수분유실을 막는 방어벽으로서의 기능과 허물을 벗는데 관여하는 것으로 확인되었다.

• 한국항공우주학회지
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• 제33권3호
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• pp.107-113
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• 2005

고성능 로켓엔진 연소기의 벽면 열유속 측정을 위하여 추력 2톤급 칼로리미터를 개발하였으며 고온에서 전열특성과 강도특성이 뛰어난 크롬동합금을 연소실 내벽 소재로 적용하였다. 전체적인 냉각성능은 경험식을 기반으로 하는 1차원 해석으로 확인하였으며 국부적인 냉각성능은 3차원 CFD 해석으로 검증하였다. 연소압 53 bar 조건에서 노즐목에서의 열유속은 43 $MW/m^{2}$ 으로 예측되었다. 연소실의 구조적인 안전성은 150 bar에서 2차원 해석과 시편에 대한 변형실험으로 확인하였다. 최종적으로 상온 150 bar에 대한 가압실험으로 안전성을 검증하였고 개발된 칼로리미터와 동일한 냉각성능을 갖는 시험용 노즐을 사용하여 예비시험을 수행하였다. 노즐목에서 측정된 열유속이 설계값에 비하여 10% 높았음에도 연소실 내벽에 열손상은 발생하지 않았다.

• 한국건축시공학회지
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• 제21권5호
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• pp.507-518
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• 2021

외단열시스템에서 준불연 성능을 확보한 부착식 탄산칼슘계 복합단열판은 효과적인 단열성능과 화재안전성을 강화한 것으로, 본 연구에서는 준불연 복합단열판을 대상으로 부착식 준불연 외단열시스템의 구조설계 기초데이터를 확보하기 위하여 복합단열판 및 구성재의 역학적 시험을 수행하였다. 국내외 시험규격을 참조하여 시험체를 제작하였으며, 인장강도, 압축강도, 굴곡강도, 전단강도를 시험 평가하였다. 시험결과로부터 준불연 복합단열판의 강도특성치를 도출하였고, 현행 KS M ISO 4898에서 제시하는 최소 요구물성을 확보하고 있는 것을 검증하였다. 또한, 본 연구에서 사용한 준불연 외단열시스템은 지속적 중량 하중을 받지 않는 벽체의 외단열시스템으로 사용이 가능한 것을 확인하였다.