• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.73-75
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• 1989

Chaotic states of a low-frequency modulating C.W .Co2 laser beam is observed. The output behaviors appear quasi-periodicity and chaotic states when the laser beam is modulated from 100Hz to 1000Hz by using an intracavity chopper. And the output characteristics of the laser beam show a route to chaos as increasing input power when the modulation speed is 500Hz.

• 설비공학논문집
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• 제14권12호
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• pp.1004-1013
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• 2002

Turbulent carbon dioxide flows and cooling heat transfers under supercritical state in a straight duct with a square cross-section are numerically analyzed employing low Reynolds number $\kappa-\varepsilon$ model and algebraic stress model. The flow is assumed to be (quasi-incompressible. Predicted Nusselt number and friction factor are compared with the experimental data, Blasius correlation for friction factor and Dittus-Boelter correlation for Nusselt number. Computational results for the Fanning's friction factor agree well with the all Rohsenow and Choi's correlation, Liou and Hwang's experimental data and Blasius correlation. The results obtained by algebraic stress model agree more with the Liou and Hwang's experimental data, while the results obtained by low Reynolds number $\kappa-\varepsilon$ model agree more with Blasius correlation. In the computation of Nusselt number, Dittus-Boelter correlation can not exactly fit the computational results. Therefore we propose the new correlation$Nu=0.053Re^{0.73}Pr^{0.4}$for the turbulent cooling heat transfer of carbon dioxide under supercritical state.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1997년도 추계 학술논문발표회 논문집
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• pp.117-122
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• 1997

This paper presents a study on the fuzzy based approach for the safety assessment of human body under ELF electric and magnetic(EM) field considering power system states. The analysis of ELF EM field based on quasi-static method is introduced. UP to the present, the analysis of ELF EM field has been conducted with the consideration of one transmission line, or a power line model only In this paper, however, the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes and the states are classified into two types, normal state resulting from normal operation and emergency state from outages. In order to analyze the uncertainty in the normal state, the Monte Carlo Simulation, a statistic approach was introduced and line current and bus voltage distribution are calculated by a contingency analysis method, in the emergency state. To access the safety of human body, the approach based on fuzzy linguistic variable is adopted to overcome the shortcomings of the assessment by a crisp set concept. In order to validate the usefulness of the approach suggested herein, the case study using a sample system with 765(kV) was done. The results are presented and discussed.

• 종양간호연구
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• 제12권2호
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• pp.125-131
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• 2012

Purpose: This study was designed to examine the effects of horticultural therapy program on state-anxiety, fatigue and quality of life (QoL) of among women cancer survivors. Methods: Quasi-experimental study was used with a nonequivalent control group pretest-posttest design. Data were collected from February to June, 2009. Participants consisted of 40 women cancer survivors in community. The experimental group participated in horticultural therapy program once a week for 18 weeks. Data were analyzed with SPSS/WIN 18.0 program using ${\chi}^2$-test and t-test. Results: There were significant differences between the two groups in state-anxiety and QoL. Conclusion: The results of this study support that horticultural therapy program was effective in decreasing state-anxiety and improving QoL among women cancer survivors.

• 성인간호학회지
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• 제16권3호
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• pp.452-459
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• 2004

Purpose: To investigate the effect of oral care either with normal saline or with tantum solution on the oral state of the patients in intensive care unit as well as the frequency of bacteria occurrence inside their oral cavities. Method: The study was performed from March thru May of 2003 on the nonequivalent control group non-synchronized quasi-experimental design. Forty subjects were selected for each group. The data were analyzed using the SPSS 10.0 Win. The pre-experimental homogeneity and post-experimental differences between the two groups were analyzed with t-test. Result: There was a significant difference in the oral cavity state between the experimental group that had used normal saline and the control group that had used tantum solution. Conclusion: Based on the results described above, it is considered that normal saline is more effective than the tantum solution for the oral care of the patients in intensive care unit.

• 한국정보처리학회논문지
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• 제5권8호
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• pp.2091-2101
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• 1998

상호운용성은 정보기술 및 통신분야에서 가장 중요한 요소의 하나이다. 본 논문에서는 상호운용성에 관한 시험방법 및 시험 스위트의 생산에 대하여 논의하고 있다. 적합성시험을 비롯하여 정형적인 검즈에서 가장 먼저 고려되는 치명적인 문제점은 상태공간의 폭발에 관한 사항이며 이는 상호운용성의 시험방법 및 시험 스위트의 개발에 있어서도 가장 먼저 해결되어야 할 문제이다. 본 논문에서는 페트리네트를 이용한 상운용성 시험을 지원하기 위해 새로운 상태 공간 축약 방법을 제시하며 이를 이용한 상호운용성의 시험방법 및 시험 스위트 생성 방안을 IOSM, Quasi stable state 등을 이용하여 HOSS에 기반한 상태축약 결과를 보임으로써 상호운용성시험을 효율적으로 지원하는 방안을 제시한다.

• 기본간호학회지
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• 제18권1호
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• pp.54-62
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• 2011

Purpose: The purpose of this study was to test the effects of aroma inhalation on subjective quality of sleep, state anxiety, and depression of mothers who underwent a Cesarean section delivery. Methods: This study was designed as a nonequivalent control group quasi-experimental study based upon data acquired through a pre-post test. The experimental group (n=33) was given general obstetric nursing care plus dry inhalation method using lavender essential oil, in which each mother put one drop on a tissue and breathe near it for 5 minutes before going to bed. Then they put 1~2 drops on their pillow for 6 nights. The control group (n=34) was only given general obstetric nursing care. Data were collected using a questionnaire for measures of subjective quality of sleep, state anxiety, and depression by self-report. ${\chi}^2$-test, Fisher's exact test, t-test, and ANCOVA with SPSS/Win12.0 were used to analyze the data. Results: There were significant differences in subjective quality of sleep (p<.001), state anxiety (p=.049) and depression (p=.029). Conclusion: The results suggest that aroma inhalation method can be an effective nursing intervention to improve quality of sleep and decrease anxiety and depression in postpartum mothers suffering from stress related to a Cesarean section delivery.

• Advances in aircraft and spacecraft science
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• 제4권3호
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• pp.297-316
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• 2017

With rapid growth in the complexity of large scale engineering systems, the application of multidisciplinary analysis and design optimization (MDO) in the engineering design process has garnered much attention. MDO addresses the challenge of integrating several different disciplines into the design process. Primary challenges of MDO include computational expense and poor scalability. The introduction of a distributed, collaborative computational environment results in better utilization of available computational resources, reducing the time to solution, and enhancing scalability. SORCER, a Java-based network-centric computing platform, enables analyses and design studies in a distributed collaborative computing environment. Two different optimization algorithms widely used in multidisciplinary engineering design-VTDIRECT95 and QNSTOP-are implemented on a SORCER grid. VTDIRECT95, a Fortran 95 implementation of D. R. Jones' algorithm DIRECT, is a highly parallelizable derivative-free deterministic global optimization algorithm. QNSTOP is a parallel quasi-Newton algorithm for stochastic optimization problems. The purpose of integrating VTDIRECT95 and QNSTOP into the SORCER framework is to provide load balancing among computational resources, resulting in a dynamically scalable process. Further, the federated computing paradigm implemented by SORCER manages distributed services in real time, thereby significantly speeding up the design process. Part 1 covers SORCER and the algorithms, Part 2 presents results for aircraft panel design with curvilinear stiffeners.

• Advances in aircraft and spacecraft science
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• 제4권3호
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• pp.317-334
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• 2017

With rapid growth in the complexity of large scale engineering systems, the application of multidisciplinary analysis and design optimization (MDO) in the engineering design process has garnered much attention. MDO addresses the challenge of integrating several different disciplines into the design process. Primary challenges of MDO include computational expense and poor scalability. The introduction of a distributed, collaborative computational environment results in better utilization of available computational resources, reducing the time to solution, and enhancing scalability. SORCER, a Java-based network-centric computing platform, enables analyses and design studies in a distributed collaborative computing environment. Two different optimization algorithms widely used in multidisciplinary engineering design-VTDIRECT95 and QNSTOP-are implemented on a SORCER grid. VTDIRECT95, a Fortran 95 implementation of D. R. Jones' algorithm DIRECT, is a highly parallelizable derivative-free deterministic global optimization algorithm. QNSTOP is a parallel quasi-Newton algorithm for stochastic optimization problems. The purpose of integrating VTDIRECT95 and QNSTOP into the SORCER framework is to provide load balancing among computational resources, resulting in a dynamically scalable process. Further, the federated computing paradigm implemented by SORCER manages distributed services in real time, thereby significantly speeding up the design process. Part 1 covers SORCER and the algorithms, Part 2 presents results for aircraft panel design with curvilinear stiffeners.

• 근관절건강학회지
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• 제29권2호
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• pp.133-140
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• 2022

Purpose: This study was to examine the effects of auricular acupressure on competitive state anxiety and the accuracy of breaking in taekwondo players. Methods: This study was a quasi-experimental study with a time-series design. Twenty-two taekwondo breaking players were assigned to the control group for the first two weeks and then assigned to the experimental group for the next two weeks. Anxiety was measured by the revised Competitive State Anxiety Inventory-2 and the accuracy of breaking was measured as a percentage of breaking the wooden board. Results: Auricular acupressure for two weeks significantly increased the accuracy of breaking from 80.83±7.99% to 90.92±7.57% (t=7.74, p<.001). Auricular acupressure for two weeks significantly increased anxiety from 35.66±10.36 to 50.64±7.45 (t=4.38, p<.001). Among three subtypes of competitive state anxiety, somatic anxiety was increased from 12.48±4.97 to 22.95±4.54 (t=2.09, p=.011). Cognitive anxiety was significantly increased from 10.11±3.96 to 14.68±3.89 (t=5.37, p<.001) but self-confidence was not changed. Conclusion: The results of this study showed that auricular acupressure was effective in increasing the accuracy of breaking in taekwondo players.