• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.43-49
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• 2016

Reliability characteristics of thin package-on-packages were evaluated using T/H (temperature/humidity) test at $85^{\circ}C/85%$ for 500 hours, TC (temperature cycling) test at $-40{\sim}100^{\circ}C$ for 1,000 cycles, and HTS (high temperature storage) test at $155^{\circ}C$ for 1,000 hours. The average resistance of the solder-bump circuitry between the top and bottom packages of 24 package-on-package (PoP) samples, which were processed using polyimide thermal tape, was $0.56{\pm}0.05{\Omega}$ and quite similar for all 24 samples. Open failure of solder joints did not occur after T/H test for 500 hours, TC test for 1,000 cycles, and HTS test for 1,000 hours, respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.259-266
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• 2022

This study aims to introduce missile live-fire during the ship operational test and evaluation(T&E) as a means of verifying the integrated combat capability(ICC) of various systems installed on naval ships. The research method identified domestic and foreign T&E systems and cases, and reports related to ICC, which were written during the ship's design stage. As a result of research, Republic of Korea is not conducting the missile live-fire at the ship T&E stage due to the lack of relevant systems, while the U.S. is conducting it based on the mission-based T&E and the end-to-end test system. As a way to improve within the current domestic ship acquisition systems, the reaction time analysis, a quantitative analysis result of ICC calculated at the ship basic design stage, was proposed to be verified by missile live-fire during ship operational T&E.

• Journal of Korean Academy of Nursing
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• v.28 no.1
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• pp.132-142
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• 1998

This study was conducted to investigate whether exercise therapy applied in an efficacy expectation promoting program based on the self-efficacy theory of Bandura(1977) would increase self-efficacy and metabolism in NIDDM patients. The study design was a nonequivalent control group pre-test post-test quasi-experimental desist The exercise therapy applied in the efficacy expectation promoting program was composed of a staged exercise program, a small booklet relating personal experience with diabetes mellitus and a telephone coaching program on performance accomplishment. vicarious experience and verbal persuasion, which are all induction modes of efficacy expectation. The subjects of the study were twenty eight NIDDM patients who received follow-up care regularly through the out-patient department of endocrine medicine in one general hospital which had a diabetic clinic. Fourteen were assigned to the experimental group and fourteen to the control group. The experimental group participated in the exercise therapy applied in the efficacy expectation promoting program from three to five times per week for four weeks and the control group did not have the program. The collected data were analyzed using the X²-test, t-test, paired t-test, and Cronbach's Alpha using SPSS /PC/sup +/. The results are summarized as follows 1. Experimental group had higher efficacy score than control group(t=5.98, p=.00). And. There was a significant different in the efficacy score before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(t=-6.42, p=.00). 2. Experimental group did not have lower level of glucose metabolism than control group(FBS : t=.32, p=.75, HbAlC : t=.60, p=.55, pc 2hrs. glucose : t=-.29, p=.78). But, There was a significant different in the aunt of glucose metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(FBS : t=3.63, p=.003, HbAlC t=4.20, p=.00, pc 2hrs. glucose : t=1.93, p=.001). 3. Levels of lipid metabolism were partly a significant different between Experimental group and control group(triglyceride t=-1.87, p=.07, HDL cholesterol : t=-.29, p=.77. body weight : t=1.78, p=.09, Total cholesterol : t=-2.17, p=.04). And, There was partly a significant different in the amount of lipid metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(triglyceride : t=2.50, p=.03, HDL cholesterol : t=-.43, p=.67, body weight : t=5.34. p=.00, Total cholesterol : t=2.26, p=.04). In conclusion, it was found that exercise therapy applied in an efficacy expectation promoting program was an effective nursing intervention for increasing self-efficacy and metabolism.

• Communications for Statistical Applications and Methods
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• v.2 no.2
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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.

• New & Renewable Energy
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• v.16 no.4
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• pp.49-64
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• 2020

Photovoltaic and Thermal collector (PV/T) systems are renewable energy devices that can produce electricity and heat energy simultaneously using solar panels and heat exchangers. Since PV/T systems are exposed to the outdoors, their reliability is affected by various environmental factors. This paper presents a reliability test for a PV/T system and evaluates the test results. The reliability assessment entails performance, environment, safety, and life tests. The factor that had the greatest influence on the life of the system was the hydraulic pressure applied to the heat exchanger. A test was conducted by repeatedly applying pressure to the PV/T system, and a reliability analysis was conducted based on the test results. As a result, the shape parameter (β) value of 5.6658 and the B10life 308,577 cycles at the lower 95% confidence interval were obtained.

• Journal of Korean Biological Nursing Science
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• v.25 no.2
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• pp.113-122
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• 2023

Purpose: The purpose of this study was to examine the effects of a mobile application on quality of life, wellness, and preventive behaviors against dementia among older adults who use senior citizen centers. Methods: Seventy-two older adults who used senior citizen centers were allocated to an intervention group (n = 36) and a control group (n = 36). The experimental treatment involved a cognitive enhancement program for preventing dementia using a mobile application for 12 sessions over 6 weeks. Data were analyzed using the t-test, chi-square test, Fisher's exact test, paired t-test, and independent t-test. Results: The cognitive enhancement program based on a mobile application was effective for wellness (t = -3.87, p < .001) and preventive behaviors against dementia (t = -3.98, p < .001) for older adults who used a senior center. Conclusion: The mobile application-based cognitive enhancement program developed in this study is recommended as an effective intervention for dementia prevention in older adults.

• Communications for Statistical Applications and Methods
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• v.4 no.2
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• pp.581-588
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• 1997

Univariate F test is based on the multisample sphericity assumption. Robustness for tests of a main effect of the within-subjects factor was investigated when the assumptions of the onmibus F tests are violated in a split-plot design with one between-subjects factor using untrimmed data and trimmed data. The results indicate that when sample sizes are unbalanced and dispersion matrices are heterogeneous, the CIGA and the $CIGA_T$ tests better control Type I error rates than do the $F_T$test and the$\widetilde{\xi_T}$test.

• Korean Journal of Cleft Lip And Palate
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• v.7 no.2
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• pp.77-91
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• 2004

본 연구의 목적은 반안면왜소증 환자의 하악골 신장술시 초기 치아골격 특성들 중에서 치료결과의 차이에 기여하는 인자를 찾는 것이다. 치료전의 치아골격 특성, 골신장술의 효과와 그 유지상태를 관찰하기 위하여 골신장술 직전(T0), 직후(T1), 추적 2년후(T2)에 측모와 정모 두부방사선 계측사진을 촬영하여 전후방, 수직치아, 비대칭 항목들을 계측하였다. T2 시기의 계측 결과에 따라서 환자들을 1군(양호군, 10명)과 2군(불량군, 9명)으로 분류하였다. 두 군에서 각 시기와 T0-T1, T1-T2 동안의 변화량의 차이를 Mann-Whitney U test, Wilcoxon signed independent t-test, rank test, ANOVA test를 사용하여 분석하였다. pruzansky type이 골신 장술의 성공과 실패 여부와 관계가 깊게 나타났다. T0 시기에 2군은 1군에 비하여 하악골이 후방위치되었고, 하악지 고경(ramus height)이 짧았고, 하악각(gonial angle)이 컸으며, 이환측 하악지가 내측경사되었고, 이환측으로의 이부변위(chin point deviation)가 크게 나타났다. 1군에서 골신장술의 주요한 효과는 하악지 고경의 증가, 하악골의 전방위치, 하악각의 증가, articular angle의 감소에 따른 하약골의 반시계방향 회전, 이환측의 하악지 경사의 증가, 교합면경사와 이부변위의 개선으로 나타났다. 그러나 2군에서는 골신장술을 시행했을 때 1군에 비하여 하악골이 시계방향으로 회전되었고 하악지 고경의 증가량이 작게 나타났다. T2 시기에 2군에서는 하악골의 반시계방향 회전이 나타났고, 하악지 성장이 일어나지 않았으나, 1군은 반대의 경향을 보였다. 이러한 인자들이 골신장술 결과의 차이에 기여하는 것으로 생각된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.66-74
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• 2016

This study examined the effects of nursing information provision using a booklet on the patients' anxiety and uncertainty with an endoscopic submucosal dissection before the procedure, which is a non-equivalent controlled pre-post test designed study. Twenty three patients in a control group received the existing intervention, which is the general education prior to the procedure without standardized format as well as an oral explanation, and 23 patients in the experimental group received nursing information with a booklet developed by the investigator of this study. The collected data were analyzed using a ${\chi}^2$ test and Fisher's exact t-test on SPSS 21.0. The experimental group reported significantly lower anxiety (t=3.319, p=.002) and anxiety behavioral responses (t=3.508, p=.001) than those in the control group. There were no significant differences in uncertainty between the groups (t=.745, p=.460). Nursing information using the booklet is a useful nursing intervention to reduce the anxiety of patients with endoscopic submucosal dissection before the procedure.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.491-498
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• 2021

This study is presented as evidence for developing a health education program to prevent lower extermity circulatory system problems among nurses's health problem by identifying the effects of taping therapy on lower extermites discomfort and fatigue for nurses who stand for long periods of time. The study method is a similar experimental study using a nonequivalent control group pretest-posttest design in which taping therapy was applied to female nurses who work day shifts for 5 consecutive days in an orthopedic surgery ward. Data collection was from November 2 to December 18, 2020, and a total of 60 nurses, 30 in the experimental group and 30 in the control group, were recruited from two orthopedic surgery hospitals located in B city. The data were analyzed by chi-square test, t-test and paired t-test using the SPSS WIN 22.0 program. As a result of the study, the experimental group had lower extermities discomfort(t=-1.27, p=<.001) and fatigue score(t=-0.60, p=<.001) than the control group, and it was confirmed that there was a statistically significant effect. It has been proven that taping therapy is a very effective nursing intervention.