• 전력전자학회논문지
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• 제8권3호
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• pp.230-238
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• 2003

본 연구에서는 3상 SRP-PWM기법을 2상에 적용한 고정 스위칭 주파수의 공간벡터 SRP-PWM(Separately Randomized Pulse Position PWM)기법을 제안하고 이를 산업현장에 적용 가능한가를 검증하기 위하여, 속도 피드백 실험을 행하였다. 제안된 2상 SRP-PWM은 랜덤하게 배치된 a상의 펄스 범위 내에서 나머지 상의 펄스 위치를 완전히 랜덤하게 배치 할 수 있는 변조기법이다. 제안된 방법이 적용된 속도 피드백 시스템은 부하와 연결된 3상 유도모터의 v/f 일정 제어를 기반으로 하였다. 실험 결과, 제안된 방법이 적용된 기존의 2상 중앙정렬 SVM의 경우와 비교하여 모터의 v/f 일정 제어의 성능은 동일함을 확인할 수 있었으며, 모터의 전압 및 소음 스펙트럼의 광대역화 효과는 제안된 방법이 훨씬 우수함을 입증할 수 있었다.

• 대한약침학회지
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• 제21권1호
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• pp.7-13
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• 2018

Objective: Hwa-byung is one of the cultural concept of distress in Korea resulted from chronic accumulated anger. It is characterized by various symptoms like stuffy in the chest, hot or heat sensation, something pushing up in the chest, feeling of mortification, and a flush of anger. This protocol aims to explore the efficacy and safety of Huanglian-jie-du decoction on various somatic symptoms and insomnia in patients with Hwa-byung. Methods: This is study protocol for a randomized, double-blind, placebo-controlled trial. A total of 44 patients will be randomly assigned to the experimental group or the placebo group in a 1:1 ratio. All medications will be taken orally 3 times per day for 7 consecutive days. The primary outcomes are the mean changes in Patient Health Questionnaire of physical symptoms (PHQ-15) and Insomnia Severity Index (ISI) after the 7 days of administration. The secondary outcomes include the scales to assess stress response, symptoms of Hwa-byung, and state anger. Conclusion: The results of this study will provide high quality and explorative evidence to investigate the effect of Huanglian-jie-du decoction on Hwa-byung.

• 인간식물환경학회지
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• 제23권2호
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• pp.125-138
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• 2020

The aim of this study was to review previous literature to determine the effects of nature-based program for workers. This systematic review was conducted in accordance with National Evidence-based Healthcare Collaborating Agency's guidance for undertaking systematic reviews for intervention. Literature search was performed using National Assembly Digital Library, Korean Studies Information Service System, and Korea Education & Research Information Service for literature published until March 2019. The participants were full-time workers, and intervention of nature-based programs was conducted in the outdoor, indoor, and indirect nature contact exposures, with comparators in the control group who did not receive the treatment. The results showed that the programs were effective in physical, psychological, and social health. The methodological quality of randomized controlled trials (RCT) was assessed using the Cochrane Risk of Bias(RoB) tool, while non-randomized controlled trials (N-RCT) were assessed using the Cochrane Risk of bias assessment tool for non-randomized studuies (RoBANS). A total of 16 studies were selected for assessment: two RCTs, 10 N-RCTs, and four one-group pretest-posttest designs. Most interventions were provided at the workplace and in the community. There were many kinds of nature-based interventions, and forest therapy and horticultural therapy programs were most common. Various interventions for workers effectively improved job stress, depression, serum cortisol and stress-response. However, the included studies lacked methodological rigor. Future research is needed to evaluate the long-term effectiveness of nature-based programs for workers using rigorous research designs.

• Journal of the Korean Statistical Society
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• 제25권1호
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• pp.39-48
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• 1996

A new method that uses information obtained not only from randomization device but also from direct question is introduced. The new maximum likelihood estimator is compared with those of Warner(1965) and Mangat(l994). For a choice of randomized device, we propose a choice depending on the sample size n and show that our estimator is more efficient than that of Mangat under the randomization device. The proposed procedure is extended to more general one which can be easily applied to some specific cases. Under the specified conditions, it is shown that the variance of this generalized estimator is smaller than that of Warner.

• 한국임상수의학회지
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• 제31권4호
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• pp.288-292
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• 2014

A critical assumption of the standard sample size calculation is that the response (outcome) for an individual patient is completely independent to that for any other patient. However, this assumption no longer holds when there is a lack of statistical independence across subjects seen in cluster randomized designs. In this setting, patients within a cluster are more likely to respond in a similar manner; patient outcomes may correlate strongly within clusters. Thus, direct use of standard sample size formulae for cluster design, ignoring the clustering effect, may result in sample size that are too small, resulting in a study that is under-powered for detecting the desired level of difference between groups. This paper revisit worked examples for sample size calculation provided in a previous paper using nomogram to easy to access. Then we present the concept of cluster design illustrated with worked examples, and introduce design effect that is a factor to inflate the standard sample size estimates.

• 응용통계연구
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• 제6권2호
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• pp.311-318
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• 1993

본 논문에서는 Warner의 확률응답모형 대신에 강요질문모형을 반복 사용하여 응답자들이 진실되게 응답했는가에 대한 가설점검을 하고 Warner모형을 사용한 경우와 검정력을 비교하였다. 또한 강요질문모형을 사용하여 민감한 특성을 갖는 모집단비율의 추정량을 구하고 Warner모형을 사용하여 얻은 추정량들보다 효율적이 되는 조건을 찾았다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2095-2100
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• 2014

Objective: Most patients with advanced breast cancer experience resistance to endocrine treatment and eventual disease progression. This meta-analysis was designed to compare the efficacy and tolerability of fulvestrant 250mg with anastrozole 1mg in postmenopausal women with advanced breast cancer. Methods: Electronic literature databases (Cochrane Library, Medline, and Embase) were searched for randomized controlled trials (RCTs) published prior to August 2013. Only RCTs that compared fulvestrant 250mg to anastrozole 1mg in postmenopausal women with advanced breast cancer were selected. The main outcomes were time to treatment failure (TTF), time to progression (TTP), duration of response (DOR), clinical benefit rate, and tolerability. Results: Four RCTs covering 1,226 patients (fulvestrant, n=621; anastrozole, n=605) were included in the meta-analysis. Fulvestrant increased the DOR compared to anastrozole (HR =1.31, 95% confidence interval [CI] 1.13-1.51). There was no statistically significant difference between fulvestrant and anastrozole in terms of TTF (HR=1.02, 95%CI 0.89-1.17), complete response (RR=1.79, 95%CI, 0.93-3.43), and partial response (RR=0.91, 95%CI 0.69-1.21). As for safety, there was no statistical significance between the two groups for common adverse events. Conclusion: Fulvestrant 250mg is as effective and well-tolerated as anastrozole 1mg treatment for advanced breast cancer in postmenopausal women whose disease progressed after prior endocrine treatment. Thus, fulvestrant may serve as a reasonable alternative to anastrozole when resistance is experienced in breast cancer cases.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.309-317
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• 2020

Objective: One of the treatment strategies for controlling chronic pain and preventing disability is patient education. Pain neuroscience education (PNE) has been proven to be effective in explaining the biological and physiological processes associated with pain experiences to patients. The purpose of this review is to investigate the effectiveness of PNE for kinesiophobia such as avoidance response in patients with chronic pain. Design: A systematic review and meta-analysis. Methods: MEDLINE, EMBASE, CINAHL, PEDro, and the Cochrane Central Register of controlled trials databases were searched through November 2020 and included a randomized controlled trials evaluating kinesiophobia in musculoskeletal patients with chronic pain. In 8 randomized controlled trial studies, 'Cochrane's risk of bias (RoB) tool was used for qualitative analysis, and results of post-intervention were analyzed through RevMan 5.4 for quantitative analysis. Results: For this review, 8 randomized controlled trials of 369 patients with chronic pain were selected for PNE. A systematic review and meta-analysis also included 8 randomized controlled trials. The effect on kinesiophobia was more effective than the control group (-0.86; 95% confidence interval [CI], -1.22 to -0.51; heterogeneity [χ²=21.18, df=7, I²=67%]; overall effect [Z=4.80]). In addition, the effect on pain was more effective than the control group (-0.53; 95% CI, -1.05 to -0.01; heterogeneity [χ²=47.42, df=7, I²=85%]; overall effect [Z=2.01]). Conclusions: The results of this review suggest that PNE and combined PNE have a positive effect on the improvement of pain and kinesiophobia in patients with chronic pain.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1023-1028
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• 2004

A micro-pressure wave is generated by the high-speed train which enters a tunnel, and it causes explosive noise and vibration at the exit. It is known that train speed, train-tunnel area ratio, nose slenderness and nose shape mainly influence on generating micro-pressure wave. So it is required to minimize it by searching optimal values of such train shape factors and tunnel condition. In this study, response surface model, one of approximation models, is used to perform optimization effectively and analyze sensitivity of design variables. Owen's randomized orthogonal array and D-optimal Design are used to construct response surface model. In order to increase accuracy of model, stepwise regression is selected. Finally SQP(Sequential Quadratic Programming) optimization algorithm is used to minimize the maximum micro-pressure wave by using built approximation model.

• Nutrition Research and Practice
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• 제12권5호
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• pp.371-377
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• 2018

BACKGROUND/OBJECTIVES: Elevation of postprandial lipemia characterized by a rise in triglyceride (TG)-rich lipoproteins can increase the risk of atherogenesis. The objective of this study was to investigate postprandial lipemia response to a single dietary fat/sugar load test and monitor beneficial changes induced by the consumption of Platycodi radix (AP) beverage in healthy subjects. SUBJECTS/METHODS: A total of 52 subjects were randomly assigned to either placebo or AP beverage group with a high-fat shake in a randomized controlled crossover trial. Postprandial blood was collected at 0, 1, 2, 4, and 6 h and analyzed for TG and lipoprotein lipase mass. Inhibition of pancreatic lipase was determined in vitro. RESULTS: AP inhibited pancreatic lipase activity in vitro ($IC_{50}=5mg/mL$). Compared to placebo beverage, AP beverage consumption with a high-fat shake induced significant increase of plasma lipoprotein lipase mass (P = 0.0111, ${\beta}$ estimate = 4.2948) with significant reduction in very low-density lipoprotein (VLDL) TG concentration (P = 0.038, ${\beta}$ estimate = -52.69) at 6 h. Based on significant correlation between high-fat dietary scores MEDFICTS and postprandial TG responses in VLDL (P = 0.0395, r = 0.2127), subgroup analysis revealed that 6 h-postprandial VLDL TG response was significantly decreased by AP consumption in subjects with MEDFICTS ${\geq}40$ (P = 0.0291, ${\beta}$ estimate = -7214). CONCLUSIONS: AP beverage might have potential to alleviate postprandial lipemia through inhibiting pancreatic lipase activity and elevating lipoprotein lipase mass. Subgroup analysis revealed that subjects with high-fat dietary pattern could be classified as responders to AP beverage among all subjects.