단일 선로고장시 정적 안전도 향상을 위한 유연송전기기 운전 방안

임정욱,Lim, Jung-Uk 한국조명전기설비학회 2004 조명·전기설비학회논문지 Vol.18 No.3

본 논문에서는 상정사고 해석을 통해 결정된 가장 심각한 단일 선로고장에 대하여 부하차단이나 재급전을 하지 않고, 유연송전기기의 운전만으로 안전도를 향상시켜 이를 극복할 수 있는 방법을 제시하였다. 즉, 직렬, 병렬, 직병렬보상기기 등 유연송전기기의 각 종류별로 정적 안전도 여유를 최대화하고 안전도 지수를 최소화하는 방법을 개발하였고, 이를 통하여 각 유연송전기기의 최적 운전점을 결정하는 방법을 개발하였다. 여기서, 정적 안전도 지수는 선로 조류 및 모선 전압에 관한 안전도를 정량화하여 식으로 나타낸 것이다. 안전도 지수가 작아지면 안전도 여유는 커지는데, 본 논문에서는 안전도 지수를 반복계산법으로 최소화하였다. 본 논문에서는 제안한 방법은 IEEE 57모션개통에 적용하여 제안된 방법의 정당성을 수치적으로 입증하였다. This paper presents how to find proper operating points of FACTS devices to enhance the steady-state security level considering line contigency analysis. Three generic types of FACTS devices such as series controllers, shunt controllers, and series-shunt controllers are introduced and applied to moximize a security margin and to minimize security indices. Security indices related to line flows and bus voltages are utilized and minimized iteratively in this paper. Contingency analysis is performed to detect the most severe single line fault. In various load conditions, FACTS devices are tested to establish appropriate preventive or corrective action without generation re-dispatching or load shedding. The FACTS operation scheme is verified on the IEEE 57-bus system in a line-faulted contingency.

On ∗w-Finiteness Conditions

임정욱 경북대학교 자연과학대학 수학과 2023 Kyungpook mathematical journal Vol.63 No.4

Let D be an integral domain and let * be a star-operation on D. In this article, we give new characterizations of *w-Noetherian domains and *w-principal ideal domains. More precisely, we show that D is a *w-Noetherian domain (resp., *w-principal ideal domain) if and only if every *w-countable type ideal of D is of *w-finite type (resp., principal).

소형 DISPLAY 장치를 위한 비 메모리 피부 검출 알고리즘 및 HARDWARE 구현

임정욱,송진근,하주영,강봉순,Im, Jeong-Uk,Song, Jin-Gun,Ha, Joo-Young,Kang, Bong-Soon 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.8

정보의 보안 및 감시, 관리에 대한 중요성의 증대와 공항, 항만 및 일반 기업에서의 얼굴 및 피부 인식을 이용한 패스워드 제어 시스템이 활용됨으로써 피부색 검출에 관한 연구가 지속적으로 이루어져 왔다. 뿐만 아니라 광범위 통신망을 이용한 화상 통신 및 전자 결재 등 그 적용 범위가 급속하게 확산됨에 따라 정확한 피부색 검출의 중요성이 그 무엇보다 커지고 있다. 본 논문에서는 인종별로 수집된 수백 개의 인물 이미지로부터 얻어진 정보를 사용해 피부색의 YCbCr을 파악하고 이 중 Cb와 Cr 정보만을 이용하여 피부 영역을 설정하였으며, 적응적인 피부 범위 설정을 통하여 그 피부 영역의 포함 여부에 따라 피부색을 검출하는 효율적이고 간단한 구조를 제안한다. 이것은 메모리를 사용하지 않는 ID 처리를 가능하게 함으로써 모바일 장비와 같은 상대적으로 작은 크기의 하드웨어나 시스템으로의 적용을 가능하게 하였다. 그리고 선택적 모드를 추가함으로써 더욱 향상된 피부 검출을 할 수 있을 뿐 만 아니라 복잡한 알고리즘을 사용하는 기존의 얼굴 인식 기술에 상응하는 결과를 보여준다. The research of skin-tone detection has been conducting continuously to enlarge the importance in security, surveillance and administration of the information and 'Password Control System' for using face and skin recognition in airports, harbors and general companies. As well as tile rapid diffusion of the application range in image communications and an electron transaction using wide range of communication network, the importance of the accurate detection of skin color has been augmenting recently. In this paper, it will set up the boundaries of skin colors using the information of Cb and Cr in YCbCr color model of human skin color which is from hundreds compiled portrait images for each race, and suggest a efficient yet simple structure about the skin detection which has been followed by whether the comprehension of the boundaries of skin or not with adaptive skin-range set. With the possibility of the 1D Processes which does not use any memory, it is able to be applied to relatively small-sized hardware and system such as mobile apparatuses. To add the selective mode, it is not only available the improvement of tie skin detection, but also showing the correspondent results about previous face recognition technologies using complicated algorithm.

고주파 영역(~㎓)에서 다기능성 Ni-Zn 합금 박막의 전자파 차폐/흡수 특성 연구

임정욱,김연주,송풍근,권아람 한국표면공학회 2020 한국표면공학회 학술발표회 초록집 Vol.2020 No.12

우리나라 投資顧問業의 導入必要性과 課題

林頂旭 연세대학교 경영연구소 1986 연세경영연구 Vol.23 No.1

Comparison of clinical characteristics and inflammatory cytokines between hypoxemic and non-hypoxemic human adenovirus 55 pneumonia

임정욱,최준영,정호중,이지은,이진국 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.0

Objective: Adenovirus (AdV) can cause severe community acquired pneumonia, but limited data exist on the cytokine patterns of adenoviral pneumonia. Present study compared clinical characteristics and cytokine patterns of adenoviral and non-adenoviral pneumonia and further evaluated correlation with hypoxemia in adenoviral pneumonia. Methods: Pneumonia patients admitted to the Armed Forces Capital Hospital were evaluated. At admission, blood samples were acquired from the patients who have fever and radiologic evidence of pneumonia. Quantification of five cytokines (IL-6, IL-8, TNF-alpha, IFN-γ and IL-10) in sera were performed with the ELISA. Results: Among 75 pneumonia patients, 44 patients tested positive for human adenovirus-55 from respiratory specimen, while other 31 patients tested negative for adenovirus. Length of hospital stay was significantly longer in adenoviral pneumonia group. Serum concentrations of IL-6, IL-8, IL-10 and IFN-γ were all significantly higher for the adenoviral pneumonia group. Of 44 AdV pneumonia patients, 6 patients showed PaO2/FiO2 (PF) ratio less than 300.The hypoxemia group (PF<300) showed significantly lower lymphocyte and monocyte counts, and increased IL-6, IL-10 and IFN-γ concentrations. From the correlation analysis, IL-10, IL-8, IL-6 and IFN-γ showed significant correlations with PF ratio (r=-0.450, P=0.002, r=-0.345, P=0.022, r=-0.312, P=0.039, and r=-0.318, P=0.035 respectively). Conclusion: Levels of inflammatory cytokines were significantly increased in adenoviral pneumonia, and were associated with hypoxemia.

고주파 영역(~㎓)에서 조성에 따른 Ni-Zn 합금 박막의 전자파 차폐/흡수 및 부식 특성 연구

임정욱,김연주,김용환,송풍근,권아람 한국표면공학회 2021 한국표면공학회 학술발표회 초록집 Vol.2021 No.6

22.9kV급 병렬 커패시터 뱅크 내부의 아크 고장 판별을 위한 전압차동 보호 알고리즘의 개선 방안

임정욱,권영진,강상희,육유경 대한전기학회 2005 전기학회논문지A Vol.54 No.2

- This paper presents a refined protection algorithm of the unfused 22.9kV shunt capacitor banks in grounded wye connection to improve the existing algorithm using the voltage difference method. It is difficult to detect ground faults with arc near the input points or ground faults near the grounding point by the existing algorithm using only the voltage balanced relay. This paper shows that ground faults with arc near the input point can be detected by harmonics analysis of the differential voltage and that it has no impact of harmonics out of nonlinear loads which have the quantitative influence on capacitor banks. Thus the proposed method using harmonics analysis can be a proper detection method. In case of ground faults near the grounding point, an OVGR is being added recently and its validity is verified in this paper. The proposed method is applied to a 22.9kV example system and is verified that the proposed algorithm can detect clearly faults which are not easy to detect by the existing method.

Clinical impact of longitudinal change in air trapping in COPD patients and its correlation with changes in CT parameters

임정욱,이상도,오연목,이진국 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.-

Objective: Air trapping, expressed as increased residual volume (RV)/total lung capacity (TLC) is a risk factor associated with mortality and frequent exacerbations of COPD. Present study evaluated longitudinal change in clinical parameters of the COPD patients who were stratified by pattern of changes in RV/TLC over 3 years. Methods: Patients enrolled in the Korean Obstructive Lung Disease (KOLD) study cohort from June 2005 to October 2015 were evaluated. The study patients were spirometrically diagnosed with COPD. RV/TLC, an air trapping index was considered abnormal when it was≥40. Results: Total of 279 patients were evaluated. According to pattern of change in RV/TLC, patients were categorized into 4 groups: 76 in “normal to normal” (N→N), 34 in “abnormal to normal” (A→N), 33 in “normal to abnormal” (N→A) and 136 in “abnormal to abnormal” (A→A). After 3 years, the N→A group showed significant increase in expiratory/inspiratory ratio of mean lung density (MLD), and showed the most increase in emphysema index (EI), while the A→N group showed the decrease in EI. From Kaplan meier curve analysis, A→A showed the shortest overall survival (P=0.009).In 3rd year, the N→A group showed the highest proportion of frequent exacerbators, which was relatively higher than A→A group (27.3% vs 25.7%). The COPD phenotype according to RV/TLC change was independently associated with exacerbation during 1st year. Conclusion: Patients with COPD whose RV/TLC changed from normal to abnormal showed increase in expiratory/inspiratory MLD, EI and frequency of exacerbations.

헤드램프 스마트 레벨링 시스템

임정욱,이기홍,이양기 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11