• 제목/요약/키워드: case-study method

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저장탄약의 품목별 신뢰도평가 사례 연구 (A Case Study on the Reliability Assessment of Stockpile Ammunition)

  • 윤근식;이종찬
    • 품질경영학회지
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    • 제40권3호
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    • pp.259-269
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    • 2012
  • Purpose: The purpose of this study was to find out that the statistical method of stockpile reliability of ammunition by items can be applied to the reliability assessment of stockpile ammunition. Methods: We reviewed the statistical method of stockpile reliability of ammunition by items and verified the possibility of its application by case study. Results: We found that the statistical method of stockpile reliability of ammunition by items is very useful and effective to present the reliability of ammunition based on each item and to predict the change of the reliability in the future. The reliability of proximity fuse was about 94.5% and was influenced by manufacture's year and the difference between lot and lot more than storage period. Conclusion: The statistical method of stockpile reliability of ammunition by items can be applied to the reliability assessment of various stockpile ammunitions such as ammunition for mortar and canon.

흑연로 원자흡수분광법에 의한 혈액중 카드뮴 정량분석 (A Comparative Analysis of Whole Blood Cadmium by Atomic Absorption Spectrophotometry with a Graphite Furnace)

  • 박종안;오혜정;이종화
    • 한국산업보건학회지
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    • 제6권2호
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    • pp.301-312
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    • 1996
  • This study was performed to search a optimal analyzing method of cadmium in whole-blood. Cadmium was determined by graphite furnace atomic absorption spectrometry(GFAAS). We investigated the effect of ashing temperature on the absorbance of cadmium in a simple dilution(ten-fold) method with triton X-100 and matrix modifier methods treated with $NH_4H_2PO_4$(1 and 3%) and $Pd(NO_3)_2$(0.00l and 0.005%) as matrix modifier. We also compared the reported reference values of standard blood with values resulted from optimal analyzing conditions of this study. In case of a simple dilution method, when ashing temperature was set at $450^{\circ}C$, the absorbance of sample and background were $0.334{\pm}0.012$ and $1.382{\pm}0.245$, respectively. Background level was higher than the value(0.8) that can be corrected by $D_2$ background correction method. As ashing temperature was rised to $500^{\circ}C$, the absorbance of sample and background were $0.178{\pm}0.008$ and $0.711{\pm}0.223$ respectively. The higher ashing temperature($450^{\circ}C-650^{\circ}C$) was, the lower the absorbance of sample was. In case of a matrix modifier method with $NH_4H_2PO_4$(1 and 3%), when ashing temperature was rised from $500^{\circ}C$ to $650^{\circ}C$, the absorbance of sample slightly changed. The absorbances of sample at $600^{\circ}C$ were $0.230{\pm}0.017$ and $0.137{\pm}0.012$, respectively. These values were larger than that of simple dilution method. But the absorbance of background was higher than the level that can be corrected by $D_2$ method. In case of a matrix modifier method with $Pd(NO_3)_2$(0.001 and 0.005%), the absorbance of sample and background were higher than those of other methods and were stable and reproducible. When ashing temperature was over $550^{\circ}C$, the absorbance of sample was significantly decreased. In case of 0.005% $Pd(NO_3)_2$ carbon residue remained in graphite tube affected the absorbance of sample and background. From these results, We propose that in case of a simple dilution(ten-fold) method with triton X-100 ashing temperature must be maintained below $400^{\circ}C$. In order to diminish the absorbance of background, the alternative method is attenuation of injection volume or multiplication of dilution ratio. We recommend $Pd(NO_3)_2$ than $NH_4H_2PO_4$ as a matrix modifier. In case of a matrix modifier method with $Pd(NO_3)_2$ ashing temperature might be maintained below $550^{\circ}C$.

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A Sustainable System for Improving Energy Performances Applicable to the Existing Collective Housing

  • Jo, Mu-Jin;Han, Seung-Hoon
    • KIEAE Journal
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    • 제17권5호
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    • pp.25-31
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    • 2017
  • Purpose: Currently, there are many success stories coming out various energy-saving / production or eco-friendly buildings. However, these case and method didn't consider of application with existing housing and high-rise housings. In the case of Europe, the North America is gradually grew and settle through the voluntary, small, private development. But this method and system are not fit for the majority of developing countries including South Korea. Method: In this situation, this paper analyse, first arranged previous research and case study, second divided factors and re-organized factors, third analysed plan and elevation of apartment and selected main plan type and elevation type of apartment, finally analysed method of application with existing buildings and high-rise buildings by test and simulation. Result: In sum, this research finally analyzed the change of electricity and fuel consumption according to the change of insulation standard. This study has been expected to serve as a bridge of the energy housing system development and suggest new method applied to the existing housing and building.

연소관 조립체의 접착 체결부에 대한 비파괴 시험 방법 연구 (A Study on the Nondestructive Test Method for Adhesively Bonded Joint in Motor Case Assembly)

  • 황태경;이상호;김동륜;문순일
    • 비파괴검사학회지
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    • 제26권5호
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    • pp.343-352
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    • 2006
  • 본 논문에서는 금속 연소관, 단열 고무 그리고 내열 복합재로 구성된 연소관 조립체의 접착 체결 상태를 확인하기 위해 변형률, 음향방출 신호 그리고 초음파 시험자료를 이용한 비파괴 시험 방법이 제시되었다. 또한 내압 상태에서 연소관 조립체의 각 계면 접착 상태를 정량적으로 평가하기 위해 유한요소 해석이 수행되었다. 공압 시험 중 계측한 변형률 값과 음향방출 신호 상관관계 연구를 통해 연소관 조립체의 접착 건전성 평가가 가능했다. 그리고 연소관 조립체의 여러 접착 계면 중 첫 번째 계면인 연소관과 고무간의 접착은 초음파 방법으로 분류하였다. 이러한 연구를 통해 연소관 조립체의 모든 접착 계면은 1) 초기 완전 미접착, 2) 공압 시험 중 완전 접착 분리, 3) 공압 시험 중 부분 접착 분리, 4) 완전 접착 등 4가지 형태로 분류 및 검출되었다.

세장비가 큰 사각케이스 성형을 위한 초기 블랭크의 설계 및 개선에 관한 연구 (A Study on Initial Blank Design and Modification for Rectangular Case Forming with Extreme Aspect Ratio)

  • 구태완;박철성;강범수
    • 소성∙가공
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    • 제13권4호
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    • pp.307-318
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    • 2004
  • Rectangular drawn case with extreme aspect ratio is widely used for electrical parts such as a lithium-ion battery container, semi-conductor case and so on. Additionally, from the recent trend towards miniaturization of the multi-functional mobile device, demands for rectangular case with the narrow width are increased. In this study, numerical and experimental approaches for the multi-stage deep drawing process have been carried out. Based on the research results of the width of 5.95mm model, finite element analysis for storage case of rectangular cup type was verified to the width of 4.95mm. Also, a series of manufacturing experiments for rectangular case is conducted and the deformed configuration of the rectangular drawn case are investigated by comparing with the results of the numerical analysis. And the modification of the initial blank is performed to minimize the trimmed material amount. By the application of the modified blank, the sound shape of the deformed parts is improved.

사교에 작용하는 지진하중의 영향 평가 (Evaluation of Seismic Force Effects on Skew Bridges)

  • 박형기
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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    • pp.113-119
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    • 1998
  • This study is focused on evaluation of the structural behavior of skewed bridge during earthquake. The variation of natural frequencies and the lateral forces at pier shoes by the skewness and the rotational effect about vertical axis of skewed bridge due to seismic activity are analytically evaluated and identified through case studies. For this purpose, the composite steel girder highway bridges are selected as case study models. The seismic analyses by response spectrum method and time history method are performed for the selected models. It has been recognized that the frequency of longitudinal model increased as the skew angle decreased, while the lateral mode frequency showed the opposite trends. When the skew angle decreased, longitudina seismic forces of the bridge at the pier were increased but decreased in transverse direction. And it also has been found that the skewed bridges of the case study models showed the rotational behavior about vertical axis due to motion of San Fernando earthquake at Pacoima Dam.

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벽체변위에 따른 초유벽의 정적 주동 토압 (Static Lateral Active Earth Pressures with Various Wall Movements)

  • 채영수;김영진
    • 한국지반공학회지:지반
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    • 제4권2호
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    • pp.25-32
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    • 1988
  • 본 논문에서는 뒤채움이 사질토이고 수평면인 연직벽이 수평이동변위(ATRA)를 일으킬 때 토류벽에 작용하는 정적 주동토복을 Dubrova방법과 Dubrova방법에 Chang의 개념을 도입시킨 방법 각각으로 구하였다. 이 결과를 최근에 Fang and Ishibashi가 발표한 모형실험결과와 비교분석하였다. 또한 이미 발표한 바 있는 제(1985)의 벽체 정점과 저면을 중심으로 단전하는 정적 주동토압(AT, AB)의 경우도 상기모형실험결과와 비교분석하였다. 그 결과 다음과 같은 결론을 얻었다.

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사면의 안정해석에 관한 연구 (Stability Analysis of the Slopes)

  • 강우욱;조성섭;지인택
    • 한국농공학회지
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    • 제31권1호
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    • pp.58-70
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    • 1989
  • The paper compared the Bishop methed to the Fellenius method in the analysis of slope stability. Laboratory model test was carried out in the case of seepage flow considered. The results obtained from this study were summarized as follows; 1. The slice pieces of 10 were enough to analysis the slope stability. 2. The safety factor. by the Fellenius method was lower than the Bishop method by the 96 to 97% in the case of no seepage flow and by the 95 to 96% in the case of seepage flow considered. 3. Besides the parameter of soil and slope, the safety factor of slope was influenced by the height of slope. This phenomena was distinct in the height of height less than 10 meters. 4. In the case of clay, there was no difference in the safety factor of slope between Fellenius and Bishop rnethod. The safety factors of slope with the seepage flow considered were lower than those with no see-page flow. 5. The influence of cohesion on the safety factor was more significant in the Bishop method than in the Fellenius method. 6. The slope failure of model test of A and B soil samples with high permeability coefficient was taken place slightly in vicinity of toe by the concentration of stress and gradually increased 7. Under condition of same slope height, the shapper the slope, the shorter the radius and the center of critical circle appered downward and finally failure of slope occured inside the slope.

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부부간의 지위부조화와 갈등해결방법에 관한 연구 (A Study on Status Incompatibility and Marital Conflict Resolution Method.)

  • 이영숙
    • 가정과삶의질연구
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    • 제8권1호
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    • pp.49-67
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    • 1990
  • The purpose of this study is to investigate the relations between marital status incompatibility and the ways of dealing with marital conflict. Research was conducted by interview using questionnaire on 177 employed wives. Statistics used for data analysis were frequency distribution, percentage, t-test, chi-square test. 1) In resolving marital conflict four types of method are appeared, namely constructive method, passive method, evasion and physical violence. 2) Only physical violence of husband-to-wife of the four methods is related to status in-compatibility. That is the incidence rate of physical violence of husband-to-wife in incompatible couples is higher than that of compatible couples in conflict situations. 3) In case the wife's occupational status is high relative to her husband the incidence rate of physical violence of husband-to-wife is extremely high, but is significantly low in couples which are compatible in this status. 4) In case wife's status advance ent is controlled, there is significant relationship between status incompatibility and the method of conflict resolution by husband whose wife is status striver.

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한방안이비인후피부과학회지에 게재된 여드름과 관련된 논문에 관한 고찰 (The Review on the Acne Related Articles Published in the Journal of Korean Medicine Ophthalmology, Otolaryngology & Dermatology)

  • 김지수;박수연;최정화;김종한;이두희
    • 한방안이비인후피부과학회지
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    • 제27권3호
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    • pp.26-39
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    • 2014
  • Objective : This study was carried out to analyze the trends of Acne related articles that have been published in the Journal of Korean Medicine Ophthalmology, Otolaryngology & Dermatology(JKOOD). Method : We studied 29 research papers relevant to Acne that published in JKOOD from 1998 to 2013. All the paper were classified into three categories; original article, review article and case report. We sub-classified the original articles into three categories; descriptive study, analytic study and experimental study. We analyzed the case report according to various types of treatment. Results : 1. The number of searched journals is 29 papers; 17 original ordicles, 4 review articles, 8 case reports. 2. Classification of 17 original articles into three categories; 10 experimental studies, 7 descriptive studies, 0 analytic study. 3. Method of Evaluation; Korean Acne Grading System(KAGS) is used frequently in descriptive studies and experimental studies. 4. Treatment in Case reports; 7 Case reports used External medical treatments. Conclusions : It is needed to develop the methods of grading system in acne related to Oriental medicine to obtain objectivity of studies. The number of analytic study, clinical trial and experimental study is need to increase.