• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.184-187
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• 2005

SUS 304 발열선(직경 2.3mil)과 $Zr-KClO_4$ 기폭화약을 사용한 전기식 착화기에 대한 열특성을 시험하고 Fitted Wire Model로 분석한 결과, 약 $300^{\circ}C$ 부근에서 기폭화약과 관련된 열특성 파라미터가 급격하게 변화되었다. 이 현상은 기폭화약에 사용된 $KClO_4$의 상변화로 인한 흡열과 발열선과 기폭화약 계면의 물리적 변화로 발생된 것으로 판단되며, 결과로 열특성 시험으로 구한 파라미터가 유용한 온도 범위를 제시하였다.

• Communications for Statistical Applications and Methods
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• 제2권2호
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• pp.1-12
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• 1995

Let F be a life distribution with finite mean $\mu$ Then F is said to be in new better then worse than used in expectation (NBWUE(p)) class if $\varphi(u) {\geq} u$ for $0 {\leq}u{\leq}t_0$ and ${\varphi}(u) {\leq} u$ for $t_0< u {\leq} 1$ where ${\varphi}(u)$ is the scaled total-time-on-test transform and $p=F(t_0)$. We propose a testing procedure for $H_0$ : F is exponential against $H_1$ : NBWUE(p), and is not expontial, (or $H_1\;'$ : F is NWBUE (p), and is not exponential) using randomly censored data. Our procedure assumes kmowledge of the proportion p of the population that fail at or before the change-point $\t_0$. Know ledge of $\t_0$ itself is not assumed. The asymptotic normality of the test statistic is established and a Monte Carlo experiment is performed to investigate the speed of convergence of the test statistic to normality. The power of our test is also studied.

• 한국통신학회논문지
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• 제30권6C호
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• pp.532-540
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• 2005

이 논문에서는 새로운 약신호 검파 기법을 얻어, 그 기법과 국소 최적 검파 기법을 바탕으로 순차 검파 방식을 이끌어낸다. 먼저, 1부에서는 새로운 약신호 검파 기법을 제안하고, 흥미로운 문턱값 성질을 몇가지 밝히며, 여러 가지 잡음 분포에서 문턱값 보기를 다룬다. 한편, 2부에서는 제안한 순차 검파 방식의 성능을 고정 표본 검파 방식, 순차 확률비 검파 방식, 끝을 자른 순차 확률비 검파 방식의 성능과 견주어 본다.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.870-875
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• 2023

In this paper, we analyzed the revised guidance on electromagnetic (EM) interference qualification of Regulatory Guide 1.180 (Revision 2), which is published by the U.S. Nuclear Regulatory Commission for electromagnetic compatibility qualification for nuclear safety, by comparing it with that of the previous version. We confirmed that the test methods and the acceptance criteria of both CE101 and CE102 tests for conductive emission and RE102 test for radiating emission are changed in the recently revised Regulatory Guide 1.180 (Revision 2). Furthermore, we found that the revised Regulatory Guide 1.180 provides flexibility in the use of alternative methods for EM interference (EMI) qualification, in that a mix of the various base-standards is technically allowed. In addition, the primary revision of the updated Regulatory. Guide 1.180 is that MIL-STD-461G is to be adopted as the latest base-standard, instead of MIL-STD-461E. To evaluate the influence on EMI qualification for nuclear safety due to the endorsement of MIL-STD-461G, we thoroughly analyzed the modifications in the acceptance criteria and test methods for EMI qualification, and then validated the analyzed effect on the EMI qualification, which is caused by the revision of MIL-STD-461, by performing electromagnetic simulation for equipment under RE102 test.

• 가정과삶의질연구
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• 제26권2호
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• pp.13-24
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• 2008

The aim of the present study was to develop a cognitive-behavioral group therapy program for social anxiety in Korean adolescents and to examine its efficacy through pre-, post- and 2-year follow-up tests. The program included cognitive restructuring, exposure training and social skills training. KSAS-A and SASC-R were administered to 588 1st grade middle-school female students to assess their social anxiety levels. On the basis of double criteria procedure(top 10% scores on both scales), 59 students were selected initially. Individuals currently receiving clinical treatment were excluded. Finally, 40 students were selected and randomly assigned to either a treatment group or a wait-list control group. The program consisted of 12 weekly sessions, approximately 1.5-2 hours in duration. Whereas pre- and post-tests were administered to both groups, follow-up tests were administered to the treatment group only. The collected data were statistically analyzed through independent t-test and paired t-test. The results of the study were as follows: 1) At post-test students in the treatment group showed a very significant reduction in social anxiety and fear of negative evaluation by others in comparison with those in the wait-list group. 2) At post-test students in the treatment group showed a significant reduction in negative automatic thoughts in comparison with those in the wait-list group. 3) At post-test students in the treatment group showed a significant improvement in overall social skills in comparison with those in the wait-list group. 4) At post-test students in the wait-list group showed a significant increase in both social anxiety and negative automatic thoughts in comparison with those in the treatment group. 5) At 3-month, 1-year and 2-year follow-ups, the program's effectiveness was maintained.

• 한국표면공학회지
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• 제24권1호
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• pp.34-34
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• 1991

Corrosion behavior of TiN coated steel was studied in terms of thickness of interlayer Ti and TiN coating TiN was are ion plated to a thickness of 1$\mu\textrm{m}$ and 2$\mu\textrm{m}$ respectively with interlayer coating of Ti of 1$\mu\textrm{m}$, 2$\mu\textrm{m}$ and 3$\mu\textrm{m}$. Corrosion resistance of TiN coated steel was evaluated by anodic palarization test in 1N H2SO4 as well as salt spray test. Porosity of each coating was also tested by using SO2 test method. Corrosion current density decreased with increasing TiN coating thickness and Ti interlayer coating markedly enhanced the corrosion resistance. Ti interlayer coating of 2$\mu\textrm{m}$ and 3$\mu\textrm{m}$ prior to 2$\mu\textrm{m}$ TiN coating decreased the corrosion current density of active range by an order of 4 and that of passive range by an order of 2. This improvement was associated with the retardation of corrosive agent penetration with increasing coating thickness and inherent corrosion resistance of Ti interlayer. Ti interlayer coating was also very effective in improvement of corrosion resistance under salt atmosphere.

• 한국표면공학회지
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• 제25권1호
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• pp.34-39
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• 1992

Corrosion behavior of TiN coated steel was studied in terms of thickness of interlayer Ti and TiN coating. TiN was arc ion plated to a thickness of 1$\mu\textrm{m}$ and 2$\mu\textrm{m}$ respectively with interlayer coating of Ti of 1$\mu\textrm{m}$, $2\mu\textrm{m}$ and $3\mu\textrm{m}$. Corrosion resistance of TiN coated steel was evaluated by anodic palarization test in 1N $H_2$SO$_4$ as well as salt spray test. Porosity of each coating was also tested by using $SO_2$ test method. Corrosion current density decreased with increasing TiN coating thickness and Ti interlayer coating markedly enhanced the corrosion resistance. Ti interlayer coating of $2\mu\textrm{m}$ and $3\mu\textrm{m}$ prior to $2\mu\textrm{m}$ TiN coating decreased the corrosion current density of active range by an order of 4 and that of passive range by an order of 2. This improvement was associated with the retardation of corrosive agent penetration with increasing coating thickness and inherent corrosion resistance of Ti interlayer. Ti interlayer coating was also very effective in improvement of corrosion resistance under salt atmosphere.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.351-354
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• 2000

AC impedance of LiM $n_2$ $O_4$ and LiM $g_{0.1}$M $n_{1.9}$ $O_4$ samples have been studied at various temperature with charge-discharge test. AC impedance of LiM $n_2$ $O_4$ measured at -2$0^{\circ}C$, room temperature and 5$0^{\circ}C$ revealed that initial impedance before charge-discharge test was gradually decreased and become small by becoming law temperature. It indicates that the Li ion diffusion and the transfer resistance of the cathode are related to the temperature of cycling. Impedance at high temperature was suddenly increased because Mn dissolution and decomposition of electrolyte had been increased during cycling, compared to impedance at low temperature. Therefore, charge-discharge capacity was suddenly decreased at high but was slowly at low. In LiM $g_{0.1}$M $n_{1.9}$ $O_4$, impedance and capacity were stability at room temperature than there at 5$0^{\circ}C$, too. Initial impedance at 5$0^{\circ}C$ before charge-discharge test was small and impedance was suddenly increased during cycling than that at room temperature.ure.ure.

• 한국건축시공학회지
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• 제4권2호
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• pp.81-88
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• 2004

The purpose of this study is to investigate the chemical shrinkage and autogenous shrinkage of high strength cement paste and silica fume and fly ash and sand to cement ratio by the method of volumetric tests, and also investigate the autogenous shrinkage of high measurement method, and compare the results of volumetric test and linear length measurement test. A series of cement paste which have W/C ratio of 25%, 35%, 45% respectively were planed to study the effect of the W/C ratio to the shrinkages, and a series of cement paste which were replaced the cement by the silica fume and fly ash with 5%, 10%, 15% as the mass of cement respectively were planed to investigate the effects of poazolana to the shrinkages. A series of mortar which have a C/S ratio of 1:1, 1:1.5, 1:2 respectively were planed to investigate the shrinkage resistant effect of aggregate.

• 기본간호학회지
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• 제9권1호
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• pp.7-15
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• 2002

Purpose: To analyze the learning objectives and test items for Fundamentals in Nursing which were established between 1999 and 2000 and to develop these items toward a nationwide faculty workshop for national board examination for Korean nurses Results: 1. According to Bloom's taxonomy, learning objectives established in 1999 mainly consisted of two domains, comprehension (56 1%) and knowledge (27.7%). The learning objectives established in 2000, mainly consisted of comprehension (45.2%) and application (25.4%). 2. According to McGuire's taxonomy, domain of test items established in 1999 consisted of recall (66.7%). interpretation (28.0%) and problem solving (4.9%). Domain of test items established in 2000, consisted of recall (65.1%), interpretation (22.0%) and problem solving (12.9%). 3. The proportion of learning objectives in the knowledge and comprehension domains established in 200, decreased from 27.7% to 13.5%, and from 56.1% to 45.2% respectively over that of 1999. But the domain of application Increased from 5.3% to 25.4% over that of 1999. 4. With regard to McGuire's taxonomy, the proportion for the recall and interpretation domains established in 2000 decreased from 66 7% to 65.1%, and from 28.0% to 22.0% respectively. But the proportion for the problem solving domain increased from 4.9% to 12.9% over that of 1999. For type of test items, the proportion of A type established in 2000 decreased from 47.2% to 37 6%, and K type increased from 52.1% to 60.8% over that of 1999. Conclusion: The learning objectives and test items established in 2000 showed remarkable improvement compared to those established in 1999. For better learning objectives and test items in Fundamentals of Nursing, further research is recommended on essential content and standardization of job analysis for national board examination for nurses in Korea.