http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
우울증 여부에 따른 경도인지장애 환자의 신경심리학적 특징 비교
정광석(Kwang Seok Jeong),안준호(Joon Ho Ahn),방수영(Soo Young Bhang),최순호(Soon Ho Choi),김성윤(Seong Yoon Kim) 대한노인정신의학회 2012 노인정신의학 Vol.16 No.2
Objectives:The depression in the elderly often accompany with cognitive decline and the mild cognitive impairment (MCI) commonly accompany with depressive symptoms. This study was performed to compare the differences in neuropsychological characteristics between the MCI without depression and the MCI with depression. Methods:The subjects for this study were 366 MCI patient who enrolled through ‘Clinical Research Center for Dementia of South Korea (CREDOS) study’ gathered between December, 2005 and February, 2011. We divided the MCI patient into non-de-pressed group (n=187) and depressed group (n=179), and evaluated each cognitive domain with the Seoul Neuropsychological Screening Battery (SNSB) and analyzed the two group. Results:In the depressed group compared to the non-depressed group, Korean version of Mini-mental State Examination (K-MMSE) scores were lower (p<0.05), and Instrumental Activities of Daily Living (I-ADL) impairment was pronounced (p<0.05). In SNSB, the test scores of the two groups had similar levels on memory (p=0.403), language domain (p=0.098). But the test scores on attention (p<0.05), visuospatial function (p<0.05), executive function (p<0.05) domain in depression group was sig-nificantly lower than in non-depression group. Conclusion:This study shows differences in the clinical feature and neuropsychologic characteristics between the two differ-ent situations. MCI subjects with coexisting depression showed severer cognitive decline and had multiple cognitive domain im-pairment rather than single memory domain impairment.
Low-Frequency Noise 측정을 통한 Bottom-Gated ZnO TFT의 문턱전압 불안정성 연구
정광석,김영수,박정규,양승동,김유미,윤호진,한인식,이희덕,이가원,Jeong, Kwang-Seok,Kim, Young-Su,Park, Jeong-Gyu,Yang, Seung-Dong,Kim, Yu-Mi,Yun, Ho-Jin,Han, In-Shik,Lee, Hi-Deok,Lee, Ga-Won 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.7
Low-frequency noise (1/f noise) has been measured in order to analyze the Vth instability of ZnO TFTs having two different active layer thicknesses of 40 nm and 80 nm. Under electrical stress, it was found that the TFTs with the active layer thickness of 80 nm shows smaller threshold voltage shift (${\Delta}V_{th}$) than those with thickness of 40 nm. However the ${\Delta}V_{th}$ is completely relaxed after the removal of DC stress. In order to investigate the cause of this threshold voltage instability, we accomplished the 1/f noise measurement and found that ZnO TFTs exposed the mobility fluctuation properties, in which the noise level increases as the gate bias rises and the normalized drain current noise level($S_{ID}/{I_D}^2$) of the active layer of thickness 80 nm is smaller than that of active layer thickness of thickness 40 nm. This result means that the 80 nm thickness TFTs have a smaller density of traps. This result correlated with the physical characteristics analysis performmed using XRD, which indicated that the grain size increases when the active layer thickness is made thicker. Consequently, the number of preexisting traps in the device increases with decreasing thickness of the active layer and are related closely to the $V_{th}$ instability under electrical stress.
자기 부상 방식 구동원리를 이용한 다자유도 정밀 위치 시스템의 최적 설계, 모델링 및 제어에 관한 연구
정광석,백윤수,Jeong, Gwang-Seok,Baek, Yun-Su 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.5
The multi degree of freedom system using magnetic levitation has been implemented successfully. Differently from another noncontact systems, the developed system was focused on the maximization of the system stiffness under the constraint of a limited input. The variation of a relative adopting point between the magnetic pair, its location on the fixed base, and the selection of optimal specifications for the main active magnetic elements give us another chance to realize the increased robustness against external disturbances with the less control inputs. In this paper, the overall development procedures are given including the optimal design, the dynamic modeling, the various control tests, and the main issues to be solved.
패밀리 레스토랑 이벤트 활동이 고객의 관계지향성과에 미치는 영향
정광석(Kwang Suk Jung),김종원(Chong Won Kim),김정경(Jeong Kyong Kim) 한국호텔외식관광경영학회 2002 호텔경영학연구 Vol.11 No.1
The purpose of this study is as follows; first, to examine systematically visual security of assessment on event activities at the family restaurants and it`s contribution on the inclination of the customer relationship, second, to examine the efficient marketing plans of events at the family restaurants, for maximizing the enterprise profits with efficient management. The data of this study was taken from five foreign brand family restaurants(T.G.I. Friday`s, Bennigan`s, Sizzler, Outback steakhouse, Marche`) run in Seoul, Korea. It was surveyed to every 5th customers who visited from May, 1, 2001 to May, 20, 2001 and December, 20, 2001 to December, 31, 2001 in the family restaurants by an interview method of self-filling up. The results were as followings; Sales service group, low income earner group, young age-group and female group in variability verification of each group by demographic characteristics are perceived highly effect and valuation on event activities. In the difference of each group by use form the groups such as frequent visiting group, group accompanied by friends and family, highly paid group and a benefit club or a graduates` association are perceived highly effect and valuation on event activities. The factors affected to the relationship inclination of the customers, visiting the family restaurants should be embossed customer care factor in the relational quality (satisfaction, credibility) and necessary systematical approach on publicity and guidance factor in the relationship result(repurchase intention, recommendation and support)
비선형 시계열 하천생태모형 개발과정 중 시간지연단계와 입력변수, 모형 예측성 간 관계평가
정광석,김동균,윤주덕,라긍환,김현우,주기재,Jeong, Kwang-Seuk,Kim, Dong-Kyun,Yoon, Ju-Duk,La, Geung-Hwan,Kim, Hyun-Woo,Joo, Gea-Jae 한국하천호수학회 2010 생태와 환경 Vol.43 No.1
In this study, we implemented an experimental approach of ecological model development in order to emphasize the importance of input variable selection with respect to time-delayed arrangement between input and output variables. Time-series modeling requires relevant input variable selection for the prediction of a specific output variable (e.g. density of a species). Inadequate variable utility for input often causes increase of model construction time and low efficiency of developed model when applied to real world representation. Therefore, for future prediction, researchers have to decide number of time-delay (e.g. months, weeks or days; t-n) to predict a certain phenomenon at current time t. We prepared a total of 3,900 equation models produced by Time-Series Optimized Genetic Programming (TSOGP) algorithm, for the prediction of monthly averaged density of a potamic phytoplankton species Stephanodiscus hantzschii, considering future prediction from 0- (no future prediction) to 12-months ahead (interval by 1 month; 300 equations per each month-delay). From the investigation of model structure, input variable selectivity was obviously affected by the time-delay arrangement, and the model predictability was related with the type of input variables. From the results, we can conclude that, although Machine Learning (ML) algorithms which have popularly been used in Ecological Informatics (EI) provide high performance in future prediction of ecological entities, the efficiency of models would be lowered unless relevant input variables are selectively used.