노인 인구에서 신경인지기능저하와 혈청 지질농도와의 상관성

유영선,최석주,정성수,김지은,윤성욱,전동욱,백준형,박성우,이정구,추일한,김영훈 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.6

Objectives : In this study, the authors evaluated the correlation between eurocognitive impairments and serum lipids levels among Korean elderly over the age of 65. Methods : A total of 609 elderly individuals participated in this study. Screening for cognitive impairments were carried out using the Mini-Mental Status Examination-Korean version (MMSE-KC). There were 197 subjects above 1.5SD Of MMSE- KC and they were evaluated using the Korean versions of the Consortium to Establish a Registry for Alzheimer's Disease (AD) (CERAD-KC) and Geriatric Depression Scale (GDS-K). Results : There was a correlation between old age/low levels of education and AD (p<0.05, P<0.01). There was an inverse correlation between the serum level of total cholesterol and the word list recognition test scores. The serum levels of LDL cholesterol were inversely correlated with the scores on the constructional praxis test, word list recall test and word list recognition test. Inverse correlations between the serum level of triglyceride and scores on the word list recall test and word list recognition test were also observed. Conclusion : There were inverse correlations between the serum levels of lipids and language/memory function in subjects with AD.

평균내부거리를 이용한 데이터 분류에 관한 연구

유현재,김문수,조석제 韓國海洋大學校電波通信硏究所 1999 電波通信硏究所論文集 Vol.1 No.-

This paper presents an approach which classifys more accurately clusters for the data sets being different size cluster. We have more degree of membership to the large cluster and less degree of membership to the small cluster by the size of cluster. In the proposed algorithm, the internal data in the average intracluster distance was given the degree of membership more than 1. So we assume the data is proper. FCM is given the degree of membership depends on the distance between data and the center of cluster. But in the proposed algorithm, the center searching was improved about different size cluster by giving the degree of membership using the distance from each data to intracluster.

구조물의 비접촉 비파괴 검사를 위한 레이저 초음파법 적용

김재열,송경석,양동조,김유홍 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The defects evaluation of the interior and the surface would be considered as vital characteristics in predicting the total life span of the steel structure. More importantly, the understandings in the interior composite of welding zone and the notifications in the presence, the formation, and the positioning of the non-metallic inclusion are necessary as well, since there were signs of relatively high defect frequency presented in the welding zone. The ultrasonic testing is a highly recommended technique chosen from among other techniques because of variety of advantages in conducting the non-destructive testing for the welding zone. However, the ultrasonic testing had technical disadvantages referred as followings; the problems due to the couplant between the PZT and the specimen, the formations that were miniature and complex, the moving subject, and the high temperature surrounding the specimen. This research was conducted to resolve the technical disadvantages of the contact ultrasonic testing by studying the non-contact ultrasonic testing where the ultrasonic waves were transferred by the laser, and revealing the specimen defects at its interior part and its surface part. The ultimate goal of this research was to develop a non-destructive evaluation applying the laser manipulated ultrasonic method for the steel structure

초음파 비파괴 검사기법에 의한 용접결함 분류성능 비교

김재열,유신,김창현,송경석,양동조,김유홍 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

In this study, we made a comparative study of backpropagation neural network and probabilistic neural network and bayesian classifier and perceptron as shape recognition algorithm of welding flaws. For this purpose, variables are applied the same to four algorithms. Here, feature variable is composed of time domain signal itself and frequency domain signal itself. Through this process, we comfirmed advantages/disadvantages of four algorithms and identified application methods of four algorithms.

유리치은이식술의 임상증례

김유석,황규영,정승우 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.1

The free gingival graft has proven to be a predictable procedure for obtaining an increased width of attached gingiva, concomitantly increasing vestibular depth and eliminating the tension of an abnormal frenulum, and root coverage. The free gingival grafts is needed when the patient experiences discomfort during toothbrushing due to gingival recession and chewing due to an interfering lining mucosa and/or when the margin of restoration is placed in a subgingival position at sites with a thin gingiva that may favor an inflammatory tissue reaction in the presence of subgingival plaque. In this study, two patients were treated by the free gingiva1 grafts. One patient had no attached gingiva at lower left 2nd premolar, 2nd molar which were treated subgingival restoration and more inflammatory. The free gingival grafts were performed in this sites. The 1-2㎜ attached gingiva were obtained and maintained after 4monthes. The other had 3-4㎜ gingival recession at lower left 1st, 2nd premolar and experiences discomfort during toothbrushing, cold hypersensitivity. The free gingival grafts were performed in this sites. The 2-3㎜ root coverage were obtained and maintained after 30 months. The free gingival graft for increasing width and thickness of gingiva can be performed in case of subgingival restorations , gingival recession.

차체 점용접 접합부 피로강도의 실험해석

김정한,유희,염영진,주영우,주석재 울산대학교 1999 공학연구논문집 Vol.30 No.1

다양한 외부 동하중에 의한 피로파단이 발생하고 있는 승용차 차체 점용접 접합부에 대해 피로시험을 수행함으로써 전반적이 피로거동을 파악하고자 하였다. 실제 파단 발생 부재를 구성하는 차체재료중 SPCC, SPRC35, SAPH38P를 선택하여 용접조건, 동종 및 이종재료간의 접합, 두께 조합을 가급적 실차와 동일하게 적용하여 다양한 인장-전단 및 십자-인장 점용접 시편을 제작하였다. 그리고 정적시험 및 피로시험을 수행하여 강도 데이터베이스를 구축하였다. The fatigue behaviour of spot-welded joints of a car body, in which fatigue fracture occurs by various external dynamic loads, is characterized by performing fatigue tests. SPCC, SPRC35, and SAPH38P steels are selected which constitute the car body. Welding conditions and combinations of steels and thicknesses are chosen to reproduce those of a real car body and various tensile-shear and cross-tension spot-welded specimens are manufactured. Both static tests and fatigue tests are carried out, and the database of spot-weld strength is constructed.

전력계통에 있어서 무효전력 최적배분을 위한 유전알고리즘 응용

유석구,김규호 한양대학교 공학기술연구소 1995 공학기술논문집 Vol.4 No.1

This paper presents a method for optical dispatch which minimizes transmission losses and improves voltage profile of power systems using genetic algorithm based on the mechanism of natural genetics and natural selection. The constraints are VAR sources(transformer tap, generator voltage magnitude and shunt capacitor/reactor), load bus voltages and generator reactive power. Real variable-based genetic algorithms which can save coding times and maintain the accuracy are applied for optimal dispatch of reactive power. The genes of genetic algorithm consists of integers for considering discrete VAR sources. The algorithm proposed can apply to problems for large scale power systems with multi-variables and complex nonlinear functions efficiently. The proposed method is applied to IEEE 30 buses model system to show its effectiveness.

전력계통의 안전도 평가를 위한 상정사고 등급선정

유석구,김규호 한양대학교 공학기술연구소 1994 공학기술논문집 Vol.3 No.1

This paper proposes a method to select contingency ranking in power systems. Based on system operator's experience and knowledge, the membership function of fuzzy set theory is justified describing linguistic representation with heuristic rules and global severity index for each contingency is computed using fuzzy inference. Contingency ranking harmful to the system is formed by the index for security evaluation. The effectiveness of the proposed method is demonstrated by contingency ranking of model system.

협부 화상반흔의 교정에 있어서 Cervicofacial Flap의 이용

유성종,이학수,김석권,김성수 大韓成形外科學會 1988 Archives of Plastic Surgery Vol.15 No.4

The face and its features have been the subject of poet and artistic endeavors throughout the ages. Because a person's face is hghly visible and difficult to camouflage, large burn scar on sheek is obvious to others and may be distressing to the affected individual. Particular skill is required of the surgeon reconstructing large burn scar on cheek, because the cosmetic result will have physical and psychological implocations for patient. Cervicofacial flap has much advantages for reconstruction of large burn scar on cheek as followings; 1. Satisfactory color and controur match. 2. Excellent result in function and appearance. 3. One stage reconstruction as simple procedure. 4. Inset scar lies along nasolabial fold and RSTL. 5. No requirement of delay procedure. 6. Good viability.

흰쥐 척수 손상후 Parvalbumin과 Calbindin D-28K 함유신경세포에 관한 면역세포화학적 연구

김종중,정윤영,임유택,박상수,박영란,김현곤,문정석 조선대학교 부설 의학연구소 2002 The Medical Journal of Chosun University Vol.27 No.2

Background and Objectives: This study was done to compared the distribution of the two calcium-binding proteins immunoreactive neurons, parvalbumin immunoreactiv (PV-IR) and calbindin D-28K immunoreactive (CB-IR) neurons in the spinal cord after transection. Materials and Methods: Twenty rats were divided into 3 groups (control, complete spinal cord injury (SCI), and right and left spinal cord hemisection). SCI was produced by cutting the spinal cord use blades 11 with scalpel handles. Results: In this experiment, CB-IR neurons were mainly found in many pyramidal cells distributed in the brain stem and spinal cord of rats. PV-IR Neurons were demonstrated in all lamina of the gray matter of the spinal cord. These immunoreactive cells had the highest density in the layer I and II of dorsal horn and several nuclei of the ventral horn of the all the segments of the spinal cord. CB-IR neuropil labeling was strongly noted in all the segments of the spinal cord. In contrast PV-IR neurons were different in distribution, size and morphology in the spinal cord. The number of PV-IR neurons were greater than in the spinal cord compared with the CB-IR neurons. CB-IR and PV-IR somata were round, oval, spindle and polygonal in shape, and were unipolar, bipolar, multipolar and horizontal in types. The diameters of the somata of the PV-IR and CB-IR neurons were 40-50 ㎛, respectively. Also dendrites of PV-IR and CB-IR neurons were densely arrayed in network.