젊은 성인에서 흡연에 의한 상완동맥 내피기능의 부전에 관한 연구

이상철,권영주,방덕원,이선해,이보영,김지욱,김영훈,온영근,현민수,김성구 순천향의학연구소 2002 Journal of Soonchunhyang Medical Science Vol.8 No.1

Background and Objectives : Cigarette smoking is a major factor and the most modifiable risk factor for atherosclerosis. Endothelial dysfunction is an early event in atherosclerosis, before the structural change of the systemic arteries. We hypothesized that endothelial dysfunction might be present in the systemic arteries of young adult smokers and that this might be dose-dependent phenomenon. Therefore, we try to certify that smoking is associated with endothelial dysfunction in healthy young adults without other risk factor of atherosclerosis. Subjects and Methods : we studied noninvasively 29 subjects aged 3 to 4 decades without other risk factor of atherosclerosis, they were composed of the two groups, current smokers(n=15) and nonsmokers(n=14). Smoking history varied from 3 to 20 pack years. Using high-resolution ultrasound, vessel diameter and mean flow rate were measured at rest, during reactive hyperemia(with flow-mediated endothelium-dependent dilation), and after sublingual nitroglycerin(NG-induced endothelium-independent vasodilation). Result : Flow mediated endothelium dependent dilation was observed in the control subjects (9.4±3.44%) but was impaired in the smokers(5.8±2.51%)(p=0.004). NG-induced endothelium independent dilation is no difference in all subjects. Conclusion : Cigarette smoking is associated with endothelial dysfunction in healthy young adults.

만선신부전 환자에서 관상동맥조영술 소견에 관한 연구

한대희,김성구,박상호,김성한,조원영,방덕원,조윤행,정의룡,은영근,권영구 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Background : Patients with chronic renal fialure have a substantially elevated risk of death from cardiovascular diseases than do the general population. the patients with chronic renal failure are at significantly increased freqeuncy of hypertension, hyperlipidemia, and diabetes mellitus which are known to the risk factors of the coronary artery diseases, and the prevalence of the coronary artery diseases in chronic renal failure patients is highly associated with the hemodynamic disorder and metabolic abnormalities. therefore we expected that the coronary angiographic findings in patients with chronic renal failure should be different from the general population (control groups) and investigated the risk factors contributing to coronary artery diseases. Method : we have retrospectively compared the coronary angiographic findings of 44 patients with chronic renal failure on hemodialysis with that of 88 patients in the general population and investigated the factors contributing to the development and acceleration of coronary artery diseases in patients with chronic renal failure Result : Hypertension and diabetes mellitus which is risk factors for coronary artery disease is significantly increased in patients with chronic renal failure, in coronary angiographic finding the severity of the lesion is worse. the incidence of PCI or CABG of patients with chronic renal failure is more than that of control group but statistically no difference between patients with chronic renal failure and control group. the sex, the duration of disease, the duration of dialysis, serum creatinine in patients with chronic renal failure have no correlation to the prevalence of coronary artery disease and severity of lesion. hyperglycemic patients with chronic renal failure have high incidence of coronary artery disease and are worse in the severity of lesion Conclusions : There is significantly increased the pevalence and severity of involving multiple coronary artery diseses in hyperglycemic patients with CRF.

다중모델 퍼지 시스템을 위한 적응 모델선택 기법과 시계열 예측에의 응용

방영근,이철희 강원대학교 정보통신연구소 2009 정보통신논문지 Vol.13 No.-

Difference data are very useful for a prediction system because they can reveal the characteristics of non-stationary time series. Also, they can protect fuzzy clustering from a biased situation toward one side among fuzzy sets. But it is not easy to determine optimal difference intervals revealing patterns and regularities of time series. To overcome this problem, this paper proposes the data preprocessing procedure based on correlation analysis. Then, multiple model fuzzy systems are constructed by using the determined optimal intervals. To reflect the performances of each fuzzy system, this paper also proposes the adaptive model selection technique. The proposed technique can improve the prediction quality of fuzzy system that depends to the characteristics of input data because it is possible to control system output corresponding to system input via the adaptive model selection rules based on rough set theory. Thus, the proposed methods are more effective for prediction of non-stationary and/or chaos time series than traditional methods. In simulation and conclusion section, this paper verifies that the prediction performances of the proposed methods are very good and that the proposed methods are very effective to control the hybrid systems or multiple systems.

계층 구조 클러스터링 알고리즘 설계 및 그 응용

방영근,박하용,이철희 江原大學校 産業技術硏究所 2009 産業技術硏究 Vol.29 No.B

In many cases, clustering algorithms have been used for extracting and discovering useful information from non-linear data. They have made a great effect on performances of the systems dealing with non-linear data. Thus, this paper presents a new approach called hierarchically structured clustering algorithm, and it is applied to the prediction system for non-linear time series data. The proposed hierarchically structured clustering algorithm (called HCKA: Hierarchical Cross- correlation and K-means clustering Algorithms) in which the cross-correlation and k-means clustering algorithm are combined can accept the correlationship of non-linear time series as well as statistical characteristics. First, the optimal differences of data are generated, which can suitably reveal the characteristics of non-linear time series. Second, the generated differences are classified into the upper clusters for their predictors by the cross-correlation clustering algorithm, and then each classified differences are classified again into the lower fuzzy sets by the k-means clustering algorithm. As a result, the proposed method can give an efficient classification and improve the performance. Finally, we demonstrates the effectiveness of the proposed HCKA via typical time series examples.

무색소성 색소 실조증(Ito 저색소증) 1예

방성원,이정열,황규왕,정현,김영근 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.1

Incontinentia pigmenti achromians(IPA) or Hypomelanosis of Ito is a very rare neurocutaneous syndrome which is often associated with cutaneous, cerebral, musculoskeletal and ocular abnormalities. It is assumed that it is autosomal dominant of inheritance in character. There is also a relationship between IPA and incontinentia pigmenti(IP). However, the etiology of IPA is not known. We describe a 4-year-old girl with myopia, esotropia and retinal pigmentary degeneration in addition to the hypopigmented skin lesion of IPA, and reviewed clinically the cases of IPA in this article.

RCGKA를 이용한 최적 퍼지 예측 시스템 설계

방영근,심재선,이철희 江原大學校 産業技術硏究所 2009 産業技術硏究 Vol.29 No.B

In the case of traditional binary encoding technique, it takes long time to converge the optimal solutions and brings about complexity of the systems due to encoding and decoding procedures. However, the ROGAs (real-coded genetic algorithms) do not require these procedures, and the k-means clustering algorithm can avoid global searching space. Thus, this paper proposes a new approach by using their advantages. The proposed method constructs the multiple predictors using the optimal differences that can reveal the patterns better and properties concealed in non- stationary time series where the k-means clustering algorithm is used for data classification to each predictor, then selects the best predictor. After selecting the best predictor, the cluster centers of the predictor are tuned finely via RCGKA in secondary tuning procedure. Therefore, performance of the predictor can be more enhanced. Finally, we verifies the prediction performance of the proposed system via simulating typical time series examples.

HCBKA를 이용한 Interval Type-2 퍼지 논리시스템 기반 예측 시스템 설계

방영근,이철희 江原大學校 産業技術硏究所 2010 産業技術硏究 Vol.30 No.A

To improve the performance of the prediction system, the system should reflect well the uncertainty of nonlinear data. Thus, this paper presents multiple prediction systems based on Type-2 fuzzy sets. To construct each prediction system, an Interval Type-2 TSK Fuzzy Logic System and difference data were used, because, in general, it has been known that the Type-2 Fuzzy Logic System can deal with the uncertainty of nonlinear data better than the Type-1 Fuzzy Logic System, and the difference data can provide more steady information than that of original data. Also, to improve each rule base of the fuzzy prediction systems, the HCBKA (Hierarchical Correlation Based K-means clustering Algorithm) was applied because it can consider correlationship and statistical characteristics between data at a time. Subsequently, to alleviate complexity of the proposed prediction system, a system selection method was used. Finally, this paper analyzed and compared the performances between the Type-1 prediction system and the Interval Type-2 prediction system using simulations of three typical time series examples.

遮光度가 茶葉의 Chlorophyll 色素에 미치는 영향

정영민,김동연,은종방,박근형 全南大學校 農漁村開發硏究所 1991 農業科學技術硏究 Vol.26 No.-

차광도가 다른 재배환경이 다엽의 Chlorophyll 색소함량에 미치는 영향을 조사하고자, 재배차의 무차광 및 차광다엽, 그리고 야생차의 연중 반차광다엽과 연중 차광다엽을 대상으로 검토한 결과, Chlorophyll의 함량은 차광 정도에 따라 차이를 보였는데 무차광다엽보다 차광다엽이 높은 경향을 나타냈다. Chlorophyll a와 b의 조성은 무차광다엽은 3:1, 그리고 차광다엽은 2.8:1로 그늘에서 자란 것이 Chlorophyll b의 비율이 증가하는 경향을 나타냈다. The effect of shading on the Chlorophyll content of tea shoot was examined under the different shading conditions shaded and unshaded tea shoots obtained from cultivating tea were analyzed while partial shaded and through-shaded tea shoots were used for wild tea. Analysis of the Cholorophyll contents of tea shoots revealed that different shading conditions resulted in different Chlorophyll contents and higher content of Chlorophyll was found in the shaded case. The composition of Chlorophyll a and b was 3:1 and 2.8:1 under unshaded and shaded conditions respectively, which indicated that the ratio of Chlorophyll b to Chlorophyll a increased under the shading condition.

서울 강남지역의 高級 住宅庭園에 있어서 造景樹木 植栽現況에 관한 硏究

이민영,방광자,설종호,조근호 한국화훼연구회 1996 화훼연구 Vol.5 No.2

The planting trends, preferences of landscape plants and management type of private gardens were surveyed with centering around Bang-Bae Dong, Seo-Cho Gu, Seoul, Korea. The total number of landscape plants observed were 37 families 56 genus 91 species and the average species number per house was 16. Acer palmatum was observed most frequently and Rhododendron poukhanense, Buxus microphylla var. Koreana, Pseudocydonia sinensis and Pinus Densiflora followed it. The species number of deciduous tree were more than evergreen, but in whole planting frequency evergreen more vice versa. Between trees and shrubs, the species number of trees were more than shrub, and shrubs were more in planting frequency. The ratio of indigenous and introduced plants were 48% and 52% respectively. The garden owners premiered Syringa vulgaris pinus densiflora, Lagerstroemia indica, Rhododendron poukhanense and Ziziphus jujuba var. inermis to any other species. In management type of private garden, agent, self, and mixed were 40, 35 and 25% respectively.

미세혈관 협심증 환자의 임상상 및 지표에 관한 연구

박상호,온영근,김현정,이태훈,길효욱,김현건,박수진,송해정,한대희,방덕원,신원용,이내희,김성구,권영주 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Background : Microvascular angina or syndrom X is heterogenous and encompasses different pathogenetic entities. Several studies suggest that microvascular angina have good prognosis and occurs predominantly in postmenopausal women. Lipoprotein (a), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, homocystein, CRP and fibrinogen are the independent risk factor of acute coronary syndrome and are the chief underlying cause of atherosclerosis. We investigated clinical characteristics and markers in patients with microvascular angina. Methods : We studies 23 patients diagnosed with microvascular angina and 16 control group with negative treadmill exercise test and no significant coronary angiogram. We investigated clinical characteristics in patients group and evaluated symptom during a follow-up period of 4.2± 2.5 month. Exercise time in treadmill exercise test was compared between patients and control group. We assessed the level of markers, such as lipoprotein (a), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, homocystein, CRP and ESR in two groups. Results : There is no difference in age between two groups. Patients group had a tendency to increase in female, hypertension, DM, and smoking history, but there was no statistical significance difference. Exercise duration time was significantly decreased in patients with microvascular angina (p<0,05). Serum lipoprotein (a), total cholesterol, LDL-cholesterol, HDL-cholestrol, Triglyceride, ESR, Fibrinogen and Homocystein value were no significant difference between microvascular angina and control group. Only CRP was significantly high in patients with microvascular angina (p<0.05). Conclusion : There was no statistical significance difference in age, sex, hypertension, DM and smoking history between two groups but patients group had a tendency to increase the prevalence in hypertension, DM and smoking history, female. Also, Symptom improvement and disappearance in follow-up was presented in 11 patients of 19(57.9%). Exercise tolerance was worse in patients group than control group. CRP value was significantly higher in patients group than control group. There was no statistical significance difference in lipoprotein (a), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, homocystein, ESR and Fibrinogen between two groups.