• 대한기계학회논문집B
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• 제39권1호
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• pp.29-36
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• 2015

나노유체 개발 초기단계에서 기본유체 대비 제조한 나노유체의 열전도율이 얼마나 상승했는지 그 값을 정확히 비교하는 것이 중요하다. 지금까지는 기본유체와 나노유체의 열전도율을 비정상열선법으로 별도 측정한 후 수치적으로 나누어 비교하는 단순한 방법을 사용하였다. 이 때 두 유체의 열전도율 측정이 동시에 이루어지지 않고 절대측정방법의 특성상 측정시스템의 관련 수치들이 정확히 사용되지 않으면 개별 열전도율에 나타나는 오차를 피할 수 없다. 본 연구에서는 비교대상인 두 유체를 동시에 사용하여 열전도율 비를 상대적으로 측정하는 새로운 방법을 제시하였다. 기존 비정상열선법 회로를 변형한 측정회로와 데이터 처리과정을 자세히 설명하였고 엔진오일과 글리세린을 이용한 검증실험을 통하여 제시된 방법의 타당성을 검토하였다.

• 대한기계학회논문집B
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• 제36권10호
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• pp.989-999
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• 2012

이젝터는 고압의 유체를 구동관로에서 분출시켜, 그 주변의 저압기체와 운동량 교환을 통하여 저압의 유체를 보다 높은 압력까지 상승시켜 흡인되는 유체를 이송하는 장치이다. 증기-증기 이젝터는 흡입, 혼합 및 탈수에 널리 사용되고 있다. 그리고 이젝터는 기계적인 작동이 없으므로, 고장이 거의 없다. 또한 이젝터는 유체 관련 시스템의 크기에 관계없이 유체와 관련된 다양한 장소에 용이하게 설치할 수 있어, 정비의 필요성이 거의 없고 비용도 합리적이다. 따라서 본 연구는 단순 압축 또는 진공 설비를 위한 펌프 혹은 기계장치 대안으로 사용되는 이젝터 전체에 적용할 수 있는 기초 자료 제공을 목표로 하였다. 이 목표를 위해 실험만으로 획득할 수 없는 자료를 전산유체역학을 적용하여 분석함으로써 이젝터의 유체역학적 특성에 있어 최적의 설계조건을 제시하였다.

• Clinics in Shoulder and Elbow
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• 제2권1호
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• pp.1-7
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• 1999

Purpose : There has been considerable controversy as to the method of the treatment of acute acromioclavicular joint dislocation classified to type III injury. The purpose of this study is to compare the conservative and operative treatment of the type III acute acromioclavicular joint dislocation in terms of clinical and radiological results. Materials and Methods: We treated 31 cases of acute, type III acromioclavicular joint dislocation, 17 cases were treated by operative methods and 14 patients by conservative treatment, and 1 year minimum follow-up was done from January 1990 to January 1996. We used UCLA Shoulder Rating Scale for clinical results. And for the radiological results coracoclaviclar distance were measured. We used Fisher's exact test for statistical analysis of results between the two treatment methods. Results: Fifteen(88.2%) of seventeen patients in operative treatment and eleven(78.6%) of fourteen patients in nonoperative treatment were rated excellent or good on the UCLA rating scale. In radiographic evaluation, the average coracoclavicular distances of preoperative state, immediate postoperation(or postreduction) and last follow-up were as follows. In operative cases, it was 1.75±0.21mm, 1.14±0.24mm and 1.33± 0.22mm respectively. In nonoperative cases, it was 1.65±0.14mm, 1.26±0.26mm, and 1.42±0.27mm respectively. Conclusion : This study demonstrated that there was no significant difference in clinical and radiological results between the operative and nonoperative treatment groups. So, nonoperative treatment is recommended for acute type III acromioclavicular dislocation as general rule.

• 대한한방내과학회지
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• 제30권3호
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• pp.594-603
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• 2009

Objectives : ICH breaks down blood vessels within the brain parenchyma, which finally leads to neuronal loss, drugs to treat ICH have not yet been established. In this experiment, we measured the effect of Woowhangchongshim-won (WWCSW) on intracerebral hemorrhage (ICH) in rat using microarray technology. Methods : We measured the effect of WWCSW on ICH in rat using microarray technology. ICH was induced by injection of collagenase type IV, and total RNA was isolated. Image files of microarray were measured using a ScanArray scanner, and the criteria of the threshold for up- and down-regulation was 2 fold. Hierarchical clustering was implemented using CLUSTER and TREEVIEW program, and for Ontology analysis. GOSTAT program was applied in which p-value was calculated by Chi square or Fisher's exact test based on the total array element. Results : WWCSW-treatment restored the gene expression altered by ICH-induction in brain to the levels of 76.0% and 70.1% for up- and down-regulated genes, respectively. Conclusion : Co-regulated genes by ICH model of rat could be used as molecular targets for therapeutic effects of drug including WWCSW. That is, the presence of co-regulated genes may represent the importance of these genes in ICH in the brain and the change of expression level of these co-regulated genes would also indicate the functional change of brain tissue.

• 동의생리병리학회지
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• 제34권1호
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• pp.53-59
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• 2020

Dietary habits are known to be closely related not only to chronic diseases such as cardiovascular disease and diabetes, but also to self-rated health (SRH). Consequently, there is a highly important lifestyle component in maintaining a healthy life. The aim of the present study was to determine the correlation between diverse dietary habits based on the Sasang constitutions (SC) and SRH. The data were collected from 2,984 participants who met the constitution pharmacology criteria and whose SC were clinically confirmed by SC professionals. Dietary habits were observed by assessing the regularity of diet, meal volume, and meal speed; single-answer questions were used for SRH. Fisher's exact/chi-square test and logistic regression were used to analyze the correlation between dietary habits depending on constitutional type and SRH. In association with constitutional SRH, the Taeum type is related to the amount of meal, the Soeum and Soyang types are related to the regularity of meal and meal volume. In the Taeum type, there was a significantly higher risk of lower SRH when meal volumes were irregular less than previous amounts. Irregular diet, as well as increased or decreased meal volume, negatively correlated with SRH in the Soeum type; in the Soyang type, irregular diet and decreased or irregular meal volume negatively affected SRH. This showed the presence of the different effects of dietary habits on health depending on constitution and also confirmed the association of the regularity of diet and meal volume based on constitution and the frequency of bad dietary habits with SRH. We suggest that personalized healthcare with adequate dietary improvement considering constitution is needed for health management or improvement.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.207-243
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• 2016

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and communication impairments, as well as repetitive and restrictive behaviors. The phenotypic heterogeneity of ASD has made it overwhelmingly difficult to determine the exact etiology and pathophysiology underlying the core symptoms, which are often accompanied by comorbidities such as hyperactivity, seizures, and sensorimotor abnormalities. To our benefit, the advent of animal models has allowed us to assess and test diverse risk factors of ASD, both genetic and environmental, and measure their contribution to the manifestation of autistic symptoms. At a broader scale, rodent models have helped consolidate molecular pathways and unify the neurophysiological mechanisms underlying each one of the various etiologies. This approach will potentially enable the stratification of ASD into clinical, molecular, and neurophenotypic subgroups, further proving their translational utility. It is henceforth paramount to establish a common ground of mechanistic theories from complementing results in preclinical research. In this review, we cluster the ASD animal models into lesion and genetic models and further classify them based on the corresponding environmental, epigenetic and genetic factors. Finally, we summarize the symptoms and neuropathological highlights for each model and make critical comparisons that elucidate their clinical and neurobiological relevance.

• Journal of Chest Surgery
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• 제24권11호
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• pp.1081-1089
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• 1991

Atrial fibrillation is characterized by beat to beat irregularity of shape, size, conduction time and polarity. The mechanism of atrial fibrillation can be explained by so called "Multiple wavelet theory". The adverse effect of atrial fibrillation is the decrease of cardiac output by absence of atrial kick[10 ~ 15%] and the possibility of thrombosis in the left atrium which is dangerous to develop the thromboembolism is increased. The present study was designed to assess the effect of overdrive pacing on the suppression of recurring of atrial fibrillation after open heart surgery and the results were summarized as follows: 1. There were no significant differences of factors between converting patients and non-converting patients to normal sinus rhythm by electric cardioversion after open heart surgery. 2. Among converting patients to normal sinus rhythm, there were no significant differences of factors between study group and control group. 3. Cardiothoracic Ratio on the preoperative chest film was significantly larger in the patients of recurring atrial fibrillation within 72hrs than in the patients of maintaining normal sinus rhythm. [61.7$\pm$ 1.4% vs 67.7$\pm$2.4%, p=0.03] 4. There was a significant difference of suppressive effects between overdrive pacing group and control group among recurred cases until 24, 48, and 72hours [Fisher`s exact test ; p=0.037, p=0.076, p=0.53, respectively] 5. There was a difference of the delay of recurring of atrial fibrillation between study group and control group among recurred cases within 72 hours.[53.4$\pm$6.9hr vs. 19.3$\pm$3.8 hr, p<0.01] We think that the overdrive pacing may suppress the natural pacemaker and the converted normal sinus rhythm is maintained longer than control group during critical immediate postoperative period.ve period.

• 한국수자원학회논문집
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• 제42권4호
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• pp.271-279
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• 2009

본 연구는 단순한 직사각형 하도에서 발생한 댐 붕괴 및 홍수전파 등에서 만족스러운 결과를 보였던 Riemann 근사해법을 이용한 1차원 유한체적기법을 불규칙한 하도형상의 자연하도에 적용하기 위하여 새로운 기법을 개발하는 것이 목적이다. 이를 위하여 자연하천 단면을 등가의 직사각형 단면으로 변환하는 개념을 도입하였으며, 그 결과, 운동량방정식이 수정되었다. 새롭게 개발된 기법을 정확해가 존재하는 삼각형 단면하도의 댐 붕괴 흐름에 적용하고 그 결과를 비교함으로써, 기법의 정확성 및 적용성이 검증되었다. 단면의 형상 및 단면간 거리가 균일하지 않는 자연하도에 적용한 결과는 실측수위와 비교하여 홍수파의 전파 양상, 도수의 발생 위치 및 크기, 그리고 전 구간에서의 최대 수위가 잘 일치함을 나타낸다. 본 연구결과로부터 기존의 균일한 단면을 사용하여 개발된 기법들을 복잡한 수치처리과정 없이 자연하천 단면에 직접 적용할 수 있을 것으로 판단된다.

• 한방비만학회지
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• 제8권2호
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• pp.37-47
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• 2008

Objectives The aim of the study was to investigate the difference between pattern identification of premenopausal(n=39) and climacteric(n=40) korean obese and overweight women using Syndrome Differentiation Questionaire. Methods 39 premenopausal obese women(BMI${\geq}25kg/m^2$) and 40 climacteric overweight and obese women(BMI${\geq}23kg/m^2$) were recruited from October 2007 to March 2008 in Seoul, Korea. Subjects who had other disease were rejected. Basic anthropometry and body composition were measured. Every subjects were given and filled out the Syndrome Differentiation Questionaire, and we analyzed that using Fisher's exact test. Results 1. Premenopausal women showed high frequency of food accumulation pattern(43.6%), but in climacteric women, liver qi depression pattern was frequent(57.5%, p=0.021). 2. In weighted Syndrome Differentiation Questionaire score, Premenopausal women showed high frequency of food accumulation pattern(43.6%), but in climacteric women, liver qi depression pattern was frequent(47.5%, p=0.004). 3. There were no correlation between anthropometry and scores of the each patterns. Conclusions In this study, we can find out that the dietary factors play major roles in obesity of premenopausal women and emotional factors in obese climacteric women in the view of oriental pattern identification diagnosis. But it seemed that there lacked of consideration that reflected the degree of obesity in this Syndrome Differentiation Questionaire.

• Journal of Korean Neurosurgical Society
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• 제48권2호
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• pp.125-128
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• 2010

Objective : The purpose of this study was to determine the optimal volume of injected cement and its distribution when used to treat vertebral compression fractures, and to identify factors related to subsequent vertebral fractures. Methods : A retrospective analysis of newly developing vertebral fractures after percutaneous vertebroplasty was done. The inclusion criteria were that the fracture was a single first onset fracture with exclusion of pathologic fractures. Forty-three patients were included in the study with a minimum follow up period of six months. Patients were dichotomized for the analysis by volume of cement, initial vertebral height loss, bone marrow density, and endplate-to-endplate cement augmentation. Results : None of the four study variables was found to be significantly associated with the occurrence of a subsequent vertebral compression fracture. In particular, and injected cement volume of more or less that 3.5 cc was not associated with occurrence (p = 0.2523). No relation was observed between initial vertebral height loss and bone marrow density (p = 0.1652, 0.2064). Furthermore, endplate-to-endplate cement augmentation was also not found to be significantly associated with a subsequent fracture (p = 0.2860) by Fisher's exact test. Conclusion : Neither volume of cement, initial vertebral height loss, bone marrow density, or endplate-to-endplate cement augmentation was found to be significantly related to the occurrence of a subsequent vertebral compression fracture. Our findings suggest that as much cement as possible without causing leakage should be used.