• Journal of Biosystems Engineering
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• 제28권4호
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• pp.285-294
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• 2003

This study was carried out to propose a new-concept internal combustion engine which has great potential advantages to the conventional engines. Proposed new-concept engine is a kind of rotary engine. A rotor is rotating concentrically in a cylinder which is divided into two partitioning valves, and it makes four compartments in the cylinder. The volumes of each of four compartments are changing continuously with the rotor movement and performs the functions of intake, compression. expansion and exhaust simultaneously. Expected thermal efficiency for the real cycle is 26 percent at conditions of 1,000 rpm and compression ratio of 8.0, which is 3 to 4 percent higher than that of the conventional engines such as the piston engine, gas turbine and Wankel rotary engine. A simulation procedure proved that the new concept engine is functional, and has many potential advantages compared to the existing conventional engines.

• 한국과학교육학회지
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• 제16권1호
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• pp.77-86
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• 1996

The purpose of this study was to review the studies related to concept learning forcusing on the meanings, kinds, and characteristics of concepts. Then the characteristics of the concepts were analyzed in the three positions: metaphysics, epistemology, and psychology. It was identified that the word 'concept' were confused with the other words such as conception, construct, idea, notion, identity. It was also found that researchers defined the concepts by the use of various meanings. The instructional strategies for scientific concepts were also analyzed in this study. The study found that the instructional strategies for concept learning were developed according to the views about the nature of concepts. Described on the paper are three types of instructional models for science concepts suggested by constructivists as follows: concept formation, concept differentiation, and exchange. They developed the models based on the current research on the misconceptions of major scientific concepts.

• 대한가정학회지
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• 제31권1호
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• pp.85-95
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• 1993

The purpose of this study was to investigate the relationship between adolescent's attachment on parent and self-concept. The subjects were 271 students in the second grade of the junior high school in Busan. The Inventory of Parent and Peer Attachment scale(IPPA) and the Self-Concept test were used for collecting data. For the statistical analysis of data, t-test, F-test, Scheffe test, Pearson correlation and Regression were used. The results were as follows : 1. There were significant differences in attachment according to socio-demographic variables(sex, parent's age, parent's education, parent's job, income). 2. There were significant differences in self-concept according to socio-demographic variables(sex, parent's age, parent's education, parent's job, income). 3. Adolescent's attachment on parent was significantly correlated with adolescent's self-concept.

• 대한화학회지
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• 제67권5호
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• pp.319-332
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• 2023

Guide to the Expression of Uncertainty in Measurement (GUM)가 발간된 1993년부터 측정불확도는 측정학의 핵심 개념으로 여겨져 왔으며 적절한 불확도 평가의 중요성은 꾸준히 높아지고 있다. 하지만 측정불확도의 개념과 GUM에 대해 충분히 정확하고 상세하게 설명하는 국문 자료는 거의 없는 실정이다. 본 총설은 측정불확도 개념과 GUM의 수학적, 역사적, 철학적 배경을 상세하게 설명하며 화학 분야 불확도 평가의 특수성을 논한다.

• 대한간호학회지
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• 제20권3호
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• pp.324-340
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• 1990

Support has always been considered an important nursing concept. However, there is no agreement among nurse researchers as to a conceptual definition of supportive nursing or meaningful supportive behaviors. Clarification of the concept, support in nursing, is necessary to promote communication among nurses on nursing behaviors that are effective in providing support and on understanding the relevant properties and charcteristics of the concept, supportive nursing care. The objectives of the study were : 1. to analyse the concept, support in nursing, in order to provide a definition of supportive nursing care, and 2. to operationalize the definition of supportive nursing care and use it as an experimental nursing intervention for patients with low back pain. The first part of the study used the concept analysis approach developed by Walker and Avant(1983) to define the concept of supportive nursing care. The properties of supportive nursing care, defined by this analysis, included perception of supportive need, reciprocal interaction(Transaction), listening, providing empathy and information related to health, and confirmation of the patient's verbal and non - verbal response. The second part, the experimental part of the study, was done using King's(1970) Interpersonal Theory for Nursing. The concept, supportive nursing care, as defined in the concept analysis was operationalized and used as the experimental intervention. The experiment tested the effectiveness of the independent variable, supportive nursing care on the dependent variables, depression, mood and patient satisfaction, in the patients with low back pain in army hospitals. The instruments used to measure the dependent variables were Zung's(1965) Self- Rating Depression Scale, Ryman and Colleagues'(1974) Mood Questionnaire and LaMonica and Colleagues'(1986) Patient Satisfaction Scale. The experimental design used for this study was a Solomon 4 group experimental design. This design has the strength of allowing for observation of the main effects of supportive nursing care and pretesting, and for observation of the interaction effects of pretesting and supportive nursing care. The design includes one experimental group and three control groups. The Subjects of this study were 150 young male patients with low back pain on Neuro - Surgical Wards in three general army hospitals. There were 35 in the experimental group, 39 in the pre - posttest control group, 36 in the treatment - posttest control group and 40 in the posttest only control group. Supportive nursing care, as operationalized by the researcher according to the concept analysis, was given to the patients in the experimental group and the treatment -posttest control group, individually for 30 minute sessions, every other day for 5 days. Data collection was done using a questionnaire. The data were collected in a pretest one week before the supportive nursing care sessions, a posttest immediately after the sessions and follow- up test one week later. Hypotheses testing was done using 2×2 factorial analysis of variance and Meta analysis(Stouffer's Z method). The results of this study are summarized as follows : 1. Hypothesis Ⅰ, “There will be a difference on depression level between the patients with low back pain who receive supportive nursing care and those who do not receive supportive nursing care”, was supported (F＝8.49, p＜.05). 2. Hypothesis Ⅱ, “There will be a difference on mood level between the patients with low back pain who receive supportive nursing care and those who to not receive supportive nursing care”, was supported (Z meta＝2.17, p＜.05). 3. Hypothesis Ⅲ, “There will be a difference on satisfaction level between the patients with low back pain who receive supportive nursing care and those who do not receive supportive nursing care”, was supported (F＝13.67, p＜.05). 4. ANOVA, done to examine the interaction effect of history and maturation, showed no significant difference on the dependent variables between the observations of the pretest scores of the experimental group, the pretest scores of the pre- posttest control group and the posttest score of the posttest only control group. 5. To test for continuing effect of supportive nursing care, paired t-test was done to compare the scores for the dependent variables at the posttest and at the one week later follow-up test. No significant difference on the scores for the dependent variables was found between the posttest scores and the follow-up test scores for the two groups that received supportive nursing care, the experimental group and the treatment-posttest control group. In conclusion, it was found that in the case of young soldiers with low back pain in army hospitals, their depression level was decreased, their mood state was changed positively and their satisfaction level was increased by receiving supportive nursing care. Further, the effectiveness of the supportive nursing care lasted for at least one week in this study. The significance of this study to nursing is in the analysis of the concept of supportive nursing care and the demonstration of the effectiveness of supportive nursing care as an intervention within the limits of the study.

• 간호행정학회지
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• 제11권2호
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• pp.185-194
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• 2005

Purpose: Although ethical dilemma is important concept in nursing and many research is accomplished, some difference in defining ethical dilemma among researchers. Therefore the purpose of this analysis was to correct understanding and using about ethical dilemma by clarify the attributes of ethical dilemma. Method: The concept analysis model suggested by Walker and Avant(1988) is used to clarify what is meant by the term 'ethical dilemma'. Results: The defining attributes of ethical dilemma identified in this study were as follows. First, It is simultaneously occurrence that above two conflictive ethical alternatives. Second, It is ought to choose one of the above two conflictive ethical alternatives. Third, It is difficult to compare with two alternatives. Fourth, It is cannot delay the choices. Fifth, It is cannot do satisfactory resolution. Six, It is broken out fix, loss or feeling of powerlessness to an individual. Conclusion: In this study, a concept analysis of ethical dilemma was performed to more clearly understand ethical dilemma. It is hoped that this analysis will stimulate further study for developing strategies for prevention of nurses' ethical dilemma.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.425-431
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• 2001

In order to take account of the statistical properties of probability variables used in the structural analysis, the conventional approach using the safety factor based on past experience usually estimated the safety of a structure. The real structures could only be analyzed with the error in estimation of loads, material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis. Structural safety could not precisely be appraised by the traditional structural design concept. Recently, new approach based on the probability concept has been applied to the assessment of structural safety using the reliability concept. In this study, safety of structures will estimated by the reliability analysis with commercial structural software that has the tools of nonlinear elastic-plastic 3-D analysis. Experimental test result is compared to results from this research and Coan/sup 1)/ In this paper, AFOSM(Advanced First-Order Second Moment method) is applied with von Mises, Tresca and Mohr-Coulomb failure criterions. The reliability index β and probability of failure P/sub f/ can be obtained by following this practical procedure as judgement a safety of structures and necessity of reinforcing.

• 대한조선학회논문집
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• 제56권3호
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• pp.251-262
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• 2019

This paper is about design concept and simplified analysis method against dropped object events. The ships and offshore structures are exposed to various types of dropped object accidents such as laydown area struck by drill collar and topside deck hit by food container during their lifetime. Mitigation can be accomplished by proper facility layout and designing structures to safely absorb energy from accidental loads. It shall be designed to avoid loss of life, environmental pollution and loss of assets. Impact loads can lead to structural global collapse of the main structure or punching of a local barrier type structure with potential to escalate directly or indirectly to a global collapse of the structure. This study provides the background information on the issue of dropped object of the shipyard and also focuses on structural assessment of the local individual component such as deck plate, stiffener and web/girder by using simplified analysis method. The results of the simplified analysis method were compared with numerical results using non-linear finite element simulation.

• 한국응용과학기술학회지
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• 제37권4호
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• pp.944-957
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• 2020

본 연구는 2009년부터 2018년 최근 10년간 대한간호학회지와 분과학회지에 게재된 개념분석 연구의 통합적 문헌고찰 연구이다. 총 30편의 논문을 간호의 메타패러다임, 개념의 종류, 개념분석 방법, 활용정도 등 분석하였다. 결과로 간호의 메타패러다임은 인간 23편, 간호 5편, 건강 1편, 환경 1편으로 인간이 가장 많았으며, 개념의 종류는 모두 추상적인 개념으로 확인되었다. 개념 분석 방법으로는 워커 & 아벤트가 13편, 하이브리드 방법이 10편, 진화론적 방법이 7편으로 워커 & 아벤트 방법이 가장 많았으나 2018년도 이후에는 모두 하이브리드 방법이었다. 도구개발로의 진행은 확인되지 않았다. 연구 결과를 토대로 간호패러다임의 다양성과 이를 바탕으로 한 도구 개발도 필요하다.

• 한국강구조학회 논문집
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• 제11권1호통권38호
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• pp.23-31
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• 1999

결합부위의 해석을 위하여, 계산 효율과 정확성이 모두 뛰어난 단순모델의 사용이 필요한 경우가 많다. 이 단순모델은 결합부위의 특성을 잘 묘사하는 파라미터들로 구성된다. 이들 파라미터의 값은 실험을 통하여 얻어지게 된다. 따라서 단순모델은 실험에서 사용된 하중하에서는 결합부위의 거동을 잘 묘사하지만, 그외 다른 하중하에서는 결합부위의 거동을 어느 정도 구현할지 알 수 없다. 따라서 단순모델의 정확성을 객관적으로 얻을 수 있는 방법이 필요하게 된다. 본 연구에서는 역최적화 (antioptimization) 개념으로 최악의 하중조건을 정의하여, 이 하중하에서 단순모델의 정확성을 평가하는 방법을 제시하였다. 최악의 하중조건 하에서, 용접으로 체결된 3차원 결합부위의 단순모델과 2차원 구조물에서의 결합부위 단순모델의 정확성을 평가하였다.