클러스트링 기법의 성능 분석 및 칼라 양자화에 대한 응용

차지훈,박지연,전도홍 한국컴퓨터교육학회 1999 컴퓨터교육학회 논문지 Vol.2 No.4

본 논문에서는 퍼지 신경학습망에 의한 클러스트링의 성능을 분석하기 위해 기존의 클러스트링기법인 K-means와 신경망 모델에 의한 SOM을 함께 비교 조사한다. 각 알고리즘들은 인위적으로 생성한 기하학적 데이터 공간에서의 모의실험을 통해 그 성능과 특징을 도출한다. 또한 각 기법들의 화상이미지의 칼라 양자화에 대한 응용성을 검토하기 위해 실험을 통한 결과를 정량적인 측정값인 왜곡치와 처리속도의 관점에서 비교 분석한다.

MPEG 표준화 관련 최근 동향 소개

차지훈 한국컴퓨터통신연구회 2017 OSIA Standards & Technology Review Vol.30 No.3

치명적 수단을 사용한 고의적 자해 입원환자 특성

차지훈,안무업,김동원,이상규,이창현,김상미,김정혁,김형기,한재현,박경숙 대한응급의학회 2019 대한응급의학회지 Vol.30 No.5

Objective: The aim of this study was to identify the latent class, according to the risk factors, of the patients hospitalized due to intentional self-harm by lethal means. Methods: The risk factors were derived by categorizing the intentional self-harming measures by lethal (hanging, pesticide poisoning, jumping, and drowning) and non-lethal (drug poisoning and stab) measures and comparing the demographics, diseased state, and suicide-related characteristics. Latent class analysis was performed to identify the type of intentional self-harm. Results: Male (sex), elderly (age), rural (residing location), and comorbid diseases were found to be the risk factors for fatal injuries. For this, four latent classes were modeled. Factors, such as the age group between 20 to 40 years, women, and family conflict were included in the first class. The second class included the age group between 30 to 50 years, men, and financial problems. The third class covered the age group between 60 to 70 years and comorbidity. The fourth class contained the age group of 10 to 50 years, women, and mental problems. The rate of suicide and choice of fatal suicide was ranked in the order of 3 (62.7%, 21.5%), 2 (59.8%, 13.9%), 4 (36.8%, 5.7%), and 1 (29.5%, 5.9%). Conclusion: A lethal mean access control policy needs to be established for the high-risk group of self-harm. Moreover, establishing an emergency room-community link prevention policy could help reduce the re-suicide attempt among suffering patients.

Sulfonated Poly(ether ether ketone) Ion-Exchange Membrane for Membrane Capacitive Deionization Applications

차지훈,Oneeb ul Haq,최재환,이연식 한국고분자학회 2018 Macromolecular Research Vol.26 No.13

Radiological Findings of Extensively Drug-Resistant Pulmonary Tuberculosis in Non-AIDS Adults: Comparisons with Findings of Multidrug-Resistant and Drug-Sensitive Tuberculosis

차지훈,이호연,이경수,고원중,권오정,이진아,김태성,정명진 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.3

Objective: This study was designed to describe the radiological findings of extensively drug-resistant (XDR) pulmonary tuberculosis (TB) and to compare the observed findings with findings of drug-sensitive (DS) and non-XDR multidrug-resistant (MDR) TB in non-AIDS patients. Materials and Methods: From September 1994 to December 2007, 53 MDR TB patients (M:F = 32:21; mean age, 38 years) and 15 XDR TB non-AIDS patients (M:F = 8:7; mean age, 36 years) were enrolled in the study. All of the MDR TB patients had received no treatment or less than one month of anti-TB treatment. In addition, all XDR TB patients received either no anti-TB treatment or only first-line anti-TB drugs. In addition, 141 consecutive DS TB patients (M:F = 79:62; mean age, 51 years) were also enrolled in the study for comparison. Chest radiograph, CT and demographic findings were reviewed and were compared among the three patient groups. Results: For patients with XDR TB, the most frequent radiographic abnormalities were nodules (15 of 15 patients, 100%), reticulo-nodular densities (11 of 15, 73%), consolidation (9 of 15, 60%) and cavities (7 of 15, 47%) that were located mainly in the upper and middle lung zones. As seen on radiographs, significant differences were found for the frequency of nodules and ground-glass opacity lesions (all p < 0.001) (more frequent in DS TB patients than in MDR and XDR TB patients). For the use of CT, significant differences (more frequent in MDR and XDR TB patients) were found for the frequency of multiple cavities, nodules and bronchial dilatation (p = 0.001 or p < 0.001). Patients with MDR TB and XDR TB were younger as compared to patients with DS TB (p < 0.001). Imaging findings were not different between patients with MDR TB and XDR TB. Conclusion: By observation of multiple cavities, nodules and bronchial dilatation as depicted on CT in young patients with acid-fast bacilli (AFB) positive sputum, the presence of MDR TB or XDR TB rather than DS TB can be suggested. There is no significant difference in imaging findings between patients with XDR TB and MDR TB.

Azo계 발포제를 이용한 PC/ABS 블렌드의 물성 및 화학적 발포 특성

차지훈,박재우,김도영,김기홍,강동국,서관호 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.1

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차지훈 샘터사 2016 월간 샘터 Vol.557 No.-

뇌전도 측정 데이터를 이용한 게임 평가 기법

차지훈,조경은,엄기현 동국대학교 영상문화콘텐츠연구원 2009 영상문화콘텐츠연구 Vol.0 No.-

A Game Evaluation Technique with EEG Measures Um, Ky-hyun Game Evaluation is the process of evaluating the quality of the game and checking internal error of the game, which is on the verge of commercialization. Shortcomings of the existing Game Evaluation are that it is not only easy to collect objective data but easy to evaluate user experience. In this paper, the degree of concentration measured by user's electroencephalogram(EEG) is analyzed statistically and the methodology which applies in game design evaluation and game contents evaluation is proposed. Electroencephalogram helps to measure objective and quantitative state of the user and additional paper work process, which is indispensable in the past research method will be eliminated. Degree of concentration is the criterion of the user’s immersion in game and it enables to evaluate the overall design of the game. Furthermore, contents of the game will be evaluated by degree of concentration. Game evaluation based on the degree of concentration will help to overcome shortcomings of the past research methods. Also, it will be a counterproposal of the quantitative evaluation to check user’s experience. 게임 평가는 상용화를 앞둔 게임 개발 과정에서 게임 내의 오류를 검사하고 게임의 품질을 평가하는 과정이다. 기존의 게임 평가 방법은 객관적인 자료의 수집이 힘들고 사용자의 경험을 측정하는데 쉽지 않다는 단점을 갖고 있다. 이에 본 연구에서는 뇌전도를 통해 측정된 집중도를 통계적 분석으로 해석하고, 이를 게임 디자인 평가와 게임 콘텐츠 평가에 적용하는 방법을 제안한다. 뇌전도를 이용해 객관적이고 정량적인 사용자의 상태를 계측할 수 있고, 기존의 평가 방법에서 필요로 하는 플레이 이후의 문서 작성 과정을 제거할수 있다. 집중도는 게임의 몰입 정도를 파악하는 척도로써 게임의 전반적인디자인 평가와 이벤트 발생 시의 콘텐츠 평가를 가능케 한다. 뇌전도를 이용한 집중도 기반의 게임 평가는 기존 평가 방법의 단점을 극복하고, 정량적인사용자 경험 측정을 위한 새로운 대안이 될 것이다.

뇌전도 측정 데이터를 이용한 게임 평가 기법

차지훈,조경은,엄기현(Um, Ky-hyun) 동국대학교 영상문화콘텐츠연구원 2009 영상문화콘텐츠연구 Vol.2 No.-

응급의료 윤리에 대한 인식 조사

차지훈,김미란,김양원,전병민 대한응급의학회 2007 대한응급의학회지 Vol.18 No.6

Purpose: Ethical problems are common in the emergency department (ED)- much more common than is usually recognized. However, the difficult ethical dilemmas and unique aspects of ethics in emergency medicine have not been thoroughly discussed in the context of Korean emergency medicine. The purpose of this study is to evaluate the degree of general recognition of emergency medical ethics, as well as attitude toward several difficult ethical dilemmas among emergency physicians. Methods: This is a qualitative study by survey. By using a questionnaire, we surveyed on emergency physicians working in teaching- hospitals in Korea in August 2007. Results: The survey response rate was 30%, and there were 192 total respondents to the questionnaire. The results are as follows. Eighty-one percent of respondents said that they had trouble with difficult ethical dilemmas, 74% of respondents said that they need to be educated or trained to improve ethical decision-making capacity, and 58% of respondents said that they will use emergency ethical guideline actively if they are established. The ethical values that emergency physicians must possess, according to the survey responses, are agility, a sense of vocation, and prudence. With respect to questions about ending a patient’s life, we found that emergency physicians have a tendency to ignore a patient’s desires not to start CPR. Finally, in relation to colleagues and other professionals, many respondents said that they will take action to correct their medical errors. Conclusion: Study and development of emergency medical ethics will be greatly helpful to many emergency physicians. Further study and discussion must be pursued in order to establish ethical guideline.