• 대한의용생체공학회:의공학회지
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• 제7권1호
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• pp.75-79
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• 1986

In this paper, a multigate pulsed doppler system with parallel signal processing which enables the transcutaneous assesment of the blood-flow velocities of five adjacent sample volumes is developed. The outputs of the system are audio signals, velocity curves and velocity profiles of 5 adjacent sample volumes. We have applied to the major superficial arteries and obtained the detailed information about the time dependent blood-flow behavior.

• Communications for Statistical Applications and Methods
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• 제27권2호
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• pp.163-175
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• 2020

We consider a wide class of general weakly-dependent processes, called ψ-weak dependence, which unify almost all weak dependence structures of interest found in statistics under natural conditions on process parameters, such as mixing, association, Bernoulli shifts, and Markovian sequences. For detecting the tail behavior of the weakly dependent processes, change point tests are developed by means of cumulative sum (CUSUM) statistics with the empirical distribution functions of sample extremes. The null limiting distribution is established as a Brownian bridge. Its proof is based on the ψ-weak dependence structure and the existence of the phantom distribution function of stationary weakly-dependent processes. A Monte-Carlo study is conducted to see the performance of sizes and powers of the CUSUM tests in GARCH(1, 1) models; in addition, real data applications are given with log-returns of financial data such as the Korean stock price index.

• 한국산업융합학회 논문집
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• 제26권1호
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• pp.183-191
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• 2023

This study was conducted experimentally to investigate the surface temperature of the heat sink, the air temperature in the flow channel and the sample temperature by changing the channel number of channel type heat sink and the air flow rate when heating and cooling the bio sample. The target temperature of the sample was 15℃ or less as the minimum value and 82℃ or more as the maximum value. In this study, the channel number of the heat sink(N = 1, 2, 4, 5, 10) and the air flow rate(Q=25, 42, 54m³/min) were varied. The bio sample was replaced with water, and the volume of water is 4mL. The size of the heat sink is 80x73x150mm and the material is aluminum. When cooling the sample, the surface temperature, the air temperature and the sample temperature were highly dependent on the number of channels and the flow rate. However, when the sample is heated, the surface temperature, air temperature and sample temperature do not depend on the number of channels and the flow rate. It was found that the conditions for satisfying the minimum temperature of 15℃ or less when cooling the sample were the number of channels N≥5 and the flow rate Q≥42m³/min. When heating the sample, the conditions to satisfy the maximum temperature of 82℃ or more are the number of channels N≤5 and the air flow rate Q≤42m³/min.

• 한국식품영양과학회지
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• 제33권1호
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• pp.28-33
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• 2004

여러 가지 생약재와 녹용이 첨가되어 보혈 강장제, 활력강화 및 성장촉진 효과가 있는 전통 한약탕제인 녹용대보탕에 대하여 in vitro에 의한 전자 공여작용과 지질과산화 억제효과 등의 항산화 활성과 아질산염 소거효과, tyrosinase 억제효과 그리고 혈소판 응집 억제활성 등을 분석하였다. 본 실험에서 사용한 한약탕제의 총 페놀함량은 151.3$\pm$2.6 mg%로 확인되었으며, 80.9%의 전자 공여효과를 나타냈다. 리놀레산을 이용한 지질과산화 억제효과는 88.1%로 나타났으며, pH에 따른 아질산염 소거효과를 비교 검토한 결과 시료의 아질산염 소거 효과는 산성 pH에서 70%정도의 활성을 나타냈으며 pH 1.2에서 가장 높고, pH 6.0에서 가장 낮은 소거효과를 나타내 pH가 높아질수록 그 활성이 낮았다. Tyrosinase 억제효과는 80%이상으로 나타났으며, SD rat의 혈소판을 ADP로 자극하였을 때 일어나는 혈소판 응집 에 대한 저해활성을 측정한 결과 약30%의 혈소판 응집 억제효과를 보였다. 또한 이들 억제효과는 농도 의존적으로 일어남을 알 수 있었다.

• 대한약침학회지
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• 제2권1호
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• pp.51-62
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• 1999

This study was designed to investigate the effects of Guizibokryungwhan Herbal-acupuncture on the intravascular coagulation. At first 36 mice were divided normal group(n=6) and experimental group(n=30). Normal group had no treatment and experimental group was induced intravascular coagulation by injected endotoxin 0.5mg/kg into the caudal vein. The experimental group was divided Sample-A(n=12), Sarnple- B(n=12) and control group(n=6). Control group was administrated normal saline. Sample-A was injected Guizibokryungwhan Herbal-acupuncture manufactured by extraction method and Sample-B was injected Guizibokryungwhan Herbal-acupuncture manufactured by water-alcohol method. Then Sample-A and Sample-B was injected high and low concentration. All treatments were done to Kwanwon acupuncture point once a day for 5 days s.c.. The results were following. 1. Compared with the control group, the platelet count was significantly increased in high-concentrated Sample-A and Sample-B group. 2. Compared with the control group, the concentration of fibrinogen was significantly increased in all experimental groups. 3. The prothrombin time was sjgnificantly shortened in high-concentrated Sample-A and Sample-B group as compared with the control group. 4. The activated partial thromboplastin time was significantly shortened in high-concentrated Sample-A group as compared with the control group. 5. The Guizibokryungwhan Herbal-acupuncture has a concentration-dependent effects on the intravascular coagulation.

• 한국농촌생활과학회지
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• 제6권2호
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• pp.137-149
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• 1995

The first objective of this study is to examine the finanacial management practices of rural housewives. The second objective is to determine the effects of sociodemographic characteristics on financial management practices. The Deacon & Firebaugh's model of family resource management framework and previous studies were used to determine the effects, regarding a9e, income, number of family, education level, and farming/nonfarming as independent/input variables, and monthly saving and managerial behavior index as dependent/throughput variables. A sample of 179 rural housewives aged less than 60 was selected from Shihung-Si Gyonggi-Do Province. Results showed that rural housewives more frequently did keeping bills, making purchase-list and verifying purchase need than recording where money spent making financial plan, and evaluating spending. With regard to household debt use, 60% of the sample had debt the most borrower used debt for farming, 73% of borrowers paid for their debt behind the schedule, and the main source of borrowing was NACF (NongHyup). Using installment credit, the rural housewives mainly bought cosmetics. 25% of the sample had credit cards. Average debt was 6, 070, 000 won, and 81% of annual income. In terms of saving, 85% of the sample saved, and 23% of the sample lived with the money after save. The main reasons of saving were for education and marriage of children and emergency. The main saving institutions were NACF and NLCF (ChukHyup). The regression showed that income was negatively associated with monthly saving, and age was identified as the positive determinants of managerial behavior index.

• 대한수의학회지
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• 제48권3호
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• pp.357-361
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• 2008

Although power analysis is of important tool of research, investigators in veterinary medicine are unaware of the concepts of the statistical power. Two types of error occur in classical hypothesis testing and, those errors should be avoided, if possible. Since power is highly dependent on the sample size, whenever declaring non-statistically significant result they should consider the potential for committing a Type II error in their studies, which refers to the probability of falsely stating that two treatments are equivalent despite true difference between them. Also, sample size determination is one of the most important tasks facing the researcher when planning a diagnostic study, and provides valuable information on the characteristics of a test performance. This type of analysis forms the basis for proper interpretation of test results. The aim of this article was to re-evaluate some selected studies on diagnostic test reported in the domestic veterinary publications to determine the power and necessary sample size for inequality testing to ensure the desired power. Power calculations were illustrated using real-life examples of comparison of a new test and a reference test for detecting antibodies of various animal diseases. Factors affecting to the power were also discussed.

• 한국재료학회지
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• 제21권8호
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• pp.456-460
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• 2011

Microelectromechanical systems (MEMS)-fabricated suspended devices were used to measure the in-plane electrical conductivity, Seebeck coefficient, and thermal conductivity of 304 nm and 516 nm thick InGaAlAs films with 0.3% ErAs nanoparticle inclusions by volume. The suspended device allows comprehensive thermoelectric property measurements from a single thin film or nanowire sample. Both thin film samples have identical material compositions and the sole difference is in the sample thickness. The measured Seebeck coefficient, electrical conductivity, and thermal conductivity were all larger in magnitude for the thicker sample. While the relative change in values was dependent on the temperature, the thermal conductivity demonstrated the largest decrease for the thinner sample in the measurement temperature range of 325 K to 425 K. This could be a result of the increased phonon scattering due to the surface defects and included ErAs nanoparticles. Similar to the results from other material systems, the combination of the measured data resulted in higher values of the thermoelectric figure of merit (ZT) for the thinner sample; this result supports the theory that the reduced dimensionality, such as in twodimensional thin films or one-dimensional nanowires, can enhance the thermoelectric figure of merit compared with bulk threedimensional materials. The results strengthen and provide a possible direction in locating and optimizing thermoelectric materials for energy applications.

• Communications for Statistical Applications and Methods
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• 제24권1호
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• pp.1-13
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• 2017

This manuscript summarized advances in bootstrap methods for long-range dependent time series data. The stationary linear long-memory process is briefly described, which is a target process for bootstrap methodologies on time-domain and frequency-domain in this review. We illustrate time-domain bootstrap under long-range dependence, moving or non-overlapping block bootstraps, and the autoregressive-sieve bootstrap. In particular, block bootstrap methodologies need an adjustment factor for the distribution estimation of the sample mean in contrast to applications to weak dependent time processes. However, the autoregressive-sieve bootstrap does not need any other modification for application to long-memory. The frequency domain bootstrap for Whittle estimation is provided using parametric spectral density estimates because there is no current nonparametric spectral density estimation method using a kernel function for the linear long-range dependent time process.

• 한국시뮬레이션학회논문지
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• 제9권2호
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• pp.75-87
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• 2000

In this paper, nonstationary multiple sampling plans are discussed which are difficult to solve by analytical method when there exists dependency between the sample data. The initial solution is found by the sequential sampling plan using the sequential probability ration test. The number of acceptance and rejection in each step of the multiple sampling plan are found by grouping the sequential sampling plan's solution initially. The optimal multiple sampling plans are found by simulation. Four search methods are developed U and the optimum sampling plans satisfying the Type I and Type ll error probabilities. The performance of the sampling plans is measured and their algorithms are also shown. To consider the nonstationary property of the dependent sampling plan, simulation method is used for finding the lot rejection and acceptance probability function. As a numerical example Markov chain model is inspected. Effects of the dependency factor and search methods are compared to analyze the sampling results by changing their parameters.