• Journal of Chest Surgery
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• 제18권4호
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• pp.872-880
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• 1985

Myasthenia gravis is a neuromuscular transmission disorder characterized by fatigue and weakness of voluntary muscles. Although the pathogenesis is known as reduction of available acetylcholine receptors at neuromuscular junctions by autoimmune attack, the thymic role in myasthenia gravis is still unclear and under investigation. But thymectomy in the management of myasthenia gravis has become increasingly important since the first successful operation with remission of symptoms in 1939 by Blalock. From January 1983 to June 1985, authors performed 17 thymectomies for patients with myasthenia gravis. Among them, 12 patients were free from thymoma [Croup A] and 5 were coupled with thymoma [Group B]. The results were as follows: 1] Sex distribution was 11 females and 6 males. Mean age of the patients was 32.2 year old. Sex and age distribution by the Group A and B are shown Table 1. 2] Clinical manifestations of ocular symptoms were seen in 5 patients [88.2%], extremity weakness in 13 patients, bulbar weakness in 12 patients and dyspnea in 6 patients. According to the Osserman`s classification, 5 patients were in group IIA, 6 in IIB and 6 in IIC. 3] Pre-operatively, all patients were positive response to the anti-cholinesterase test and 12 patients [92.3%] revealed positive findings in electromyography [EMC] which was done in 13 patients. 4] The postoperative complications were respiratory distress in 3 patients, myasthenic crisis in 2 patients and wound disruption in one patients. 5] Pathologic examination of the thymus showed hyperplasia in 10 patients [90%] and thymoma in 5 patients, of which 4 were mixed type with invasion to the adjacent tissues and one lymphocytic type without invasion. Normal thymus was noticed in only 2 patients. 6] In postoperative evaluations, among the 12 patients c free from thymoma [Group A], complete remission of symptoms was noticed in 3 patients and improvement in 7 patients. But among the 5 patients coupled with thymoma [Group B], only one patients showed improvement [Table 8]. Therefore, remission and clinical improvement were noticed in 11 patients [64.7%] of the all and complete remission was noticed in 3 patients [17.6%].

• Steel and Composite Structures
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• 제28권3호
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• pp.319-329
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• 2018

The field around additional cutout of the floor beam web in orthotropic bridge deck was subjected to high stress concentration, especially the weld toe between floor beam and U shaped rib and the free edge of the additional cutout. Based on different considerations, different geometrical parameters of additional cutout were proposed in European, American and Japanese specifications, and there remained remarkable differences among them. In this study, considering influence of out-of-plane deformation of floor beam web and U shaped rib, parameter analysis for additional cutout under typical load cases was performed by fine finite element method. The influence of additional cutout shape and height to the stress distribution around the additional cutout were investigated and analyzed. Meanwhile, the static and fatigue test on this structure details was carried out. The stress distribution was consistent with the finite element analysis results. The fatigue property for additional cutout height of 95mm was slightly better than that of 61.5 mm.

• 재활간호학회지
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• 제8권1호
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• pp.13-19
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• 2005

Purpose: This study was aimed to identify the effects of group exercise on physiological functions in Elderly. Method: The design of research was one group pretest-posttest design. The subjects were sixty two elderly women persons over sixty years old to live in C-GUN, The exercise period was 12-weeks and frequency was three times per week. the exercise duration was sixty minites. In order to evaluate the effect of exercise, we measured %body fat, fat mass(FM), fat free mass(FFM), body mass index(BMI), body metabolic rate(BMR), Total Cholesterol(TC), Triglyceride(TG), high density lipoprotein-c(HDL-C), low density lipoprotein-c(LDL-C) before and after the 12 week's group exercise program. The data analyzed by the paired t-test using SPSS package. Result: There was significant difference in FFM(p=.000), BMR(p=.000), HDL-C(p=.010). There was no significant difference in weight(p=.122), %body fat(p=.062),, FM(p=.704), BMI(p=.136), TC(p=.125), TG(p=.064), LDL-C(p=.575) Conclusion: This group exercise for elderly women can be recommended as an effective nursing intervention for elderly women in a community.

• 유통과학연구
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• 제11권7호
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• pp.47-56
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• 2013

Purpose - In the academic literature, the researches on a comparative study on purchase behaviors of the consumers from emerging and mature markets remain limited. Therefore, this empirical study is attempted to examine the effects of country of origin (COO), brand image and corporate image on the purchase behavior of Chinese consumers (as from emerging market) and Korean consumers (as from mature market). Research Design, data, methodology - In total, 615 valid questionnaires were collected from the main cities of China and Korea respectively, and a multiple group analysis was conducted to test the hypotheses with SPSS 16.0 and AMOS18.0. Results - Chinese consumers are not influenced by country-of-origin effect, whereas Korean consumers are sensitive to it. Both Chinese and Korean consumers are sensitive to brand image, whereas corporate image does appear to influence Chinese consumers but not Korean consumers. The effects of country-of-origin are not more influential in less developed market (China) than more developed market (Korea). Conclusions - According to the results of this empirical study, the country-of-origin effect does impact Korean consumers but not Chinese consumers' purchase behavior. Therefore, multinational companies are relatively free to make the decision, if Chinese consumers are the marketing targets, when choosing manufacturing sites.

• 기술사
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• 제20권3호
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• pp.15-25
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• 1987

Statistical control charts are useful tools to monitor and control the manufacturing processes and are widely used in most Korean industries. Many Korean companies, however, do not always obtain desired results from the traditional control charts by Shewhart such as the X-chart, X-chart, X-chart, etc. This is partly because the quality charterstics of the process are not distributed normally but are skewed due to the intermittent production, small lot size, etc. In Shewhart X-chart, which is the most widely used one in Korea, such skewed distributions make the plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such shortcomings in nonnormally distributed processes, a distribution-free type of confidence interval can be used, which should be based on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for nonnormal distributions may be easily analyzed. Control limits and central lines are given for tile more famous nonnormal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, Truncated-normal distributions. Robustness of the proposed median control chart is compared with that of the X-chart, the former tends to be superior to the latter as the probability distribution of the process becomes more skewed. The average run length to detect the assignable cause is also compared when the process has a Normal or a Gamma distribution for which the properties of X are easy to verify, the proposed chart is slightly worse than the X-chart for the normally distributed product but much better for Gamma-distributed products. Average Run Lengths of the other distributions are also computed. To use the proposed control chart, the probability distribution of the process should be known or estimated. If it is not possible, the results of comparison of the robustness force us to use the proposed median control chart based on a normal distribution. To estimate the distribution of the process, Sturge's formula is used to graph the histogram and the method of probability plotting, $X^2$-goodness of fit test and Kolmogorov-Smirnov test, are discussed with real case examples. A comparison of the propose4 median chart and the X chart was also performed with these examples and the median chart turned out to be superior to the X-chart.

• 산업경영시스템학회지
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• 제10권16호
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• pp.101-106
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• 1987

Statistical control charts are useful tools to monitor and control the manufacturing processes and are widely used in most Korean industries. Many Korean companies, however, do not always obtain desired results from the traditional control charts by Shewhart such as the $\bar{X}$-chart, $\bar{X}$-chart, $\bar{X}$-chart, etc. This is partly because the quality charterstics of the process are not distributed normally but are skewed due to the intermittent production, small lot size, etc. In Shewhart $\bar{X}$-chart. which is the most widely used one in Kora, such skewed distributions make the plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such shortcomings in nonnormally distributed processes, a distribution-free type of confidence interval can be used, which should be based on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for nonnormal distributions may be easily analyzed. Control limits and central lines are given for the more famous nonnormal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, Truncated-normal distributions. Robustness of the proposed median control chart is compared with that of the $\bar{X}$-chart; the former tends to be superior to the latter as the probability distribution of the process becomes more skewed. The average run length to detect the assignable cause is also compared when the process has a Normal or a Gamma distribution for which the properties of X are easy to verify, the proposed chart is slightly worse than the $\bar{X}$-chart for the normally distributed product but much better for Gamma-distributed products. Average Run Lengths of the other distributions are also computed. To use the proposed control chart, the probability distribution of the process should be known or estimated. If it is not possible, the results of comparison of the robustness force us to use the proposed median control chart based oh a normal distribution. To estimate the distribution of the process, Sturge's formula is used to graph the histogram and the method of probability plotting, $\chi$$^2$-goodness of fit test and Kolmogorov-Smirnov test, are discussed with real case examples. A comparison of the proposed median chart and the $\bar{X}$ chart was also performed with these examples and the median chart turned out to be superior to the $\bar{X}$-chart.

• 한국전자거래학회지
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• 제14권3호
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• pp.131-151
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• 2009

u-공장이나 u-물류와 같은 유비쿼터스 지능공간에서의 서비스 선택 및 제공을 위해서는 자연스러운 인터페이스가 중요하다. 자연스러운 인터페이스의 실현을 위한 유력한 방법으로 증강현실 기술이 주목받고 있다. 증강현실은 가상현실과 다르게 실제 환경 위에 가상객체를 증강시켜 제공해주는 기술이다. 증강현실을 이용하면 사용자에게 정보를 직관적이고 협력적으로 제공해 줄 수 있는 이점이 있다. 하지만 현재 유비쿼터스 지능공간에서 구동될 전자상거래 도메인에서 활용되는 증강현실 기술은 거의 존재하지 않으며, 있더라도 등록된 마커에 해당하는 사전 정의된 정보와 서비스를 정적으로 제공하는 한계점을 가지고 있다. 따라서 본 연구의 목적은 사용자의 동적 상황을 고려한 증강현실형 전자상거래 방법론을 제안하는 것이다. 이를 실현하기 위해 인지심리학 모형인 Rescorla-Wagner Model과 Galton 자유연상 실험을 기반으로 한 연상 알고리즘을 개발하였으며 개인의 상황에 따라 연상된 서비스와 이미지가 증강현실을 통해 동적으로 제공되도록 하였다.

• 대한기계학회논문집A
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• 제34권11호
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• pp.1733-1740
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• 2010

대형 드럼세탁기의 낙하 충격에 대한 포장재의 동적 거동 분석을 수행하였다. 해석에는 충격 해석에 널리 쓰이고 있는 LS-DYNA를 사용하였으며, 자유 낙하 시의 충격 가속도와 유효 응력, 그리고 고속 카메라를 통한 포장재 압축 변형 비교를 통해 해석 결과의 신뢰성을 검증하였다. 완충 특성 및 포장재 구조 에 대한 파라미터 분석을 통해 기존 포장 구조에 대한 설계 개선안을 도출하였으며, 유통 시험을 통해 유효성을 검증하였다. 본 연구에서 사용한 해석 기법 및 분석 방법 등을 통해, 향후 드럼 세탁기의 완충 성능 및 재료비 개선에 효과적으로 기여할 수 있을 것으로 기대된다.

• 한국전산유체공학회지
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• 제8권2호
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• pp.1-7
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• 2003

The V2F turbulence model, which has shown very good performance in several test cases at low speeds, has been applied to supersonic ramp flow with 20. corner angle at the free stream Mach number of 2.79. The flow is known to manifest strong shock wave/turbulent boundary layer interactions. As a comparative study, low-Reynolds k-ε models are also considered. While the V2F model predicts wall-pressure distribution well, it relatively predicts larger separation bubble and higher skin-friction after the reattachment than the experimental data. Although the ellpticity of f equation is the characteristics of incompressible flows, the converged solutions are acquired in the compressible flow with shock waves. The effect of the realizability constraints used in the model is also examined. In contrast to the result of impinging jet flows, the realizability bounds proposed by Durbin deterioate the overall solutions of the supersonic ramp flow.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.623-626
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• 2002

The object of present study is to find the flow characteristics of centrifugal turbomachinery according to the volute shape change. The experiments were carried out for two model; volute-A designed by free vortex conditions and volute-B designed for use in high mass flow rate conditions using the volute-A test results, Flow measurements were taken in shrouded impeller with 12 backward type blades by using a five-hole pilot-tube and carried out in 4 flow rate, $Q/Q_d\;=0,43,\;1.0,\;1.27,\;1,47$, respectively, For volute-B, we found that pressure distribution was more uniform at high flow rate and from $Q/Q_d\;:\;0,43\;to\;Q/Q_d\;:\;1,20$, losses decreased and efficiency increased compare with volute-A.