• Journal of Ginseng Research
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• 제39권1호
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• pp.1-6
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• 2015

Abnormal changes in skin color induce significant cosmetic problems and affect quality of life. There are two groups of abnormal change in skin color; hyperpigmentation and hypopigmentation. Hyperpigmentation, darkening skin color by excessive pigmentation, is a major concern for Asian people with yellowe-brown skin. A variety of hypopigmenting agents have been used, but treating the hyperpigmented condition is still challenging and the results are often discouraging. Panax ginseng has been used traditionally in eastern Asia to treat various diseases, due to its immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Recently, several reports have shown that extract, powder, or some constituents of ginseng could inhibit melanogenesis in vivo or in vitro. The underlying mechanisms of antimelanogenic properties in ginseng or its components include the direct inhibition of key enzymes of melanogenesis, inhibition of transcription factors or signaling pathways involved in melanogenesis, decreasing production of inducers of melanogenesis, and enhancing production of antimelanogenic factor. Although there still remain some controversial issues surrounding the antimelanogenic activity of ginseng, especially in its effect on production of proinflammatory cytokines and nitric oxide, these recent findings suggest that ginseng and its constituents might be potential candidates for novel skin whitening agents.

• 대한의사협회지
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• 제61권11호
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• pp.638-642
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• 2018

Surgery is a very hands-on area of medical care, in that surgeons identify problems in patients' bodies and directly change them through operations. Therefore, it is not only necessary for surgeons to have a high level of expertise, but also to take considerable responsibility for the outcomes of each operation. However, surgery, which was once an object of envy, has long been a process to avoid, due to various circumstances, such as abnormal medical expenses in the medical field and social phenomena that avoids difficult work. It is unfortunate that medical professionals do not receive sympathy from others within the same medical field because of the general difficulties of the profession. The fundamental problem in this situation is the abnormal profit structure of the Korean medical system. Efforts by various related organizations will be needed to objectively evaluate the problems of the current medical insurance system and to make reasonable adjustments considering the difficulty, frequency, and resource-intensiveness of medical care.

• 한국산업융합학회 논문집
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• 제25권2_1호
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• pp.169-176
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• 2022

Prognostics and health management (PHM) is recently converging throughout the industry, one of the trending issue is to detect abnormal conditions at decanter centrifuge during water treatment facilities. Wastewater treatment operation produces corrosive gas which results failures on attached sensors. This scenario causes frequent sensor replacement and requires highly qualified manager's visual inspection while replacing important parts such as bearings and screws. In this paper, we propose anomaly detection by measuring the vibration of the decanter centrifuge based on the video camera images. Measuring the vibration of the screw decanter by applying the optical flow technique, the amount of movement change of the corresponding pixel is measured and fed into the LST M model. As a result, it is possible to detect the normal/warning/dangerous state based on LSTM classification. In the future work, we aim to gather more abnormal data in order to increase the further accuracy so that it can be utilized in the field of industry.

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.109-117
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• 2022

This paper proposes a method for detecting flight anomalies of drones through the difference between the command of flight controller (FC) and the navigation solution. If the drones make a flight normally, control errors generated by the difference between the desired control command of FC and the navigation solution should converge to zero. However, there is a risk of sudden change or divergence of control errors when the FC control feedback loop preset for the normal flight encounters interferences such as strong winds or navigation sensor abnormalities. In this paper, we propose the method with a deep neural network model that predicts the control error in the normal flight so that the abnormal flight state can be detected. The performance of proposed method was evaluated using the real-world flight data. The results showed that the method effectively detects anomalies in various situation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.295-296
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• 2021

홍채 진단학에서 홍채는 색과 홍채 구조의 변화에 따라 인간 조직, 장기들의 비정상적인 변화가 생길시 홍채지도상 해당 영역에 변화가 발생한다. 이를 통해 비정상적인 변화가 생긴 장기의 상태를 판단하거나 선천적으로 가지고 있는 병변의 유무를 판단할 수 있다. 본 논문에서는 다양한 딥러닝 신경망 중 이미지를 이용하여 학습을 진행하는데 강점을 가지고 있는 컨볼루션 신경망을 이용하여 홍채상에 나타난 병변을 분류하는 신경망 알고리즘을 설계할 것이다.

• 경영과학
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• 제27권3호
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• pp.161-196
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• 2010

This paper empirically investigates the impact of winning a service quality award on the market value in Korea. We estimates the mean "abnormal" change in the stock prices of sample firms when information of winning a service quality award was publicly announced. To access the validity of the research question, this paper employed collected 47 firms data that received the Korean Service Quality Awards so far. Event study methodology was used to analyze the effect of Korean service quality awards. The findings are as follows; The average abnormal returns on the event date are not significant at the 0.05 level which means that the receiving Korean Service Quality Awards has no influence on the firms' market value. On the other hand successive awarded firms have an increasing effect on the market value and it is significant at the 0.05 level. Furthermore, the results show that the factors of firm size such as firm's total assets are critical to vary the firms' abnormal returns. There might be some limitations in this study. The most obvious problem is the limitation of sample size. Although 518 sample cases were found during the period from 2000 to 2008, most of the cases were deleted according to the sample criteria. We are expecting the future research with more data and more precise results. Furthermore, our research consider the only two service award institutions even though there are several different service award authorities in Korea. It is needed to expand the research scope and range to adopt the various service award institutions for the future work.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.9-10
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• 2002

Human circulatory system between heart and tissue is not directly connected in normal condition but mandatory to go through the capillary system in order to fulfill its physiologic aim to deliver oxygen and nutrients, etc. to the tissue and retrieve used blood together with waste products from the tissue properly. When abnormal connection between arterial and venous system (AV fistula), these two circulatory systems respond differently to the hemodynamic impact of this abnormal connection between high pressure (artery) and low pressure (vein) system. Depending upon the location and/or degree (e.g. size and flow) of fistulous condition, each circulatory system exerts different compensatory hemodynamic response to this newly developed abnormal inter-relationship between two systems in order to minimize its hemodynamic impact to own system of different hemodynamic characteristics. Pump action of the heart can assist the failing arterial system directly to maintain arterial circulation against newly established low peripheral resistance by the AV fistula during the compensation period, while it affects venous system in negative way with increased venous loading. However, the negative impact of increased heart action to the venous system is partly compensated by the lymphatic system which is the third circulatory system to assist venous system independently with different hemodynamics. The lymphatic system with own unique Iymphodynamics based on peristaltic circulation from low resistance to high resistance condition, also increases its circulation to assist the compensation of overloaded venous system. Once these compensation mechanisms should fail to fight to newly established hemodynamic condition due to this abnormal AV connection, each system start to show different physiologic ${\underline{de}compensation}$ including heart and lymphatic system. The vicious cycle of decompensation between arterial and vein, two circulatory system affecting each other by mutually negative way steadily progresses to show series of hemodynamic change throughout entire circulation system altogether including heart. Clinical outcome of AV fistula from the compensated status to decompensated status is closely affected by various biological and mechanical factors to make the hemodynmic status more complicated. Proper understanding of these crucial biomechanical factors iii particular on hemodyanmic point of view is mandatory for the advanced assessment of biomechanical impact of AV fistula, since this new advanced concept of AY fistula based on blomechanical information will be able to improve clinical control of the complicated AV fistula, either congenital or acquired.

• 융합정보논문지
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• 제10권8호
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• pp.15-22
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• 2020

4차 산업 혁명과 데이터 환경의 급격한 변화는 기존 관계형 데이터베이스(RDB)는 기술적 한계를 드러내고 있다. IDC/금융/보험 등 전 분야에서 비정형 데이터에 대한 새로운 분석방안으로 그래프 데이터베이스(GDB) 기술에 관심이 높아지고 있다. 그래프 데이터베이스는 상호 연동된 데이터를 표현하고 광범위한 네트워크에서 연관 관계 분석에 효율적인 기술이다. 본 연구는 기존 RDB를 GDB 모델로 확장하고, 새로운 이상징후 탐지를 위해 기계학습 알고리즘(패턴인식, 클러스터링, 경로거리, 핵심추출)을 적용하였다. 성능분석 결과 이상 행위 성능(약 180배 이상)이 크게 향상되었고, RDB로 분석 불가능한 5단계 이후 이상징후 패턴을 추출할 수 있음을 확인하였다.

• 한국ITS학회 논문지
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• 제22권2호
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• pp.80-92
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• 2023

도시에 많은 사람들이 밀집하여 살아가면서 기존에 예측하지 못했던 범죄, 사고, 감염병 등의 비정상 이벤트가 발생은 도시 내 이용자 수요에 영향을 미치게 된다. 이러한 불확실성(uncertainty)이 내포된 정보를 기반으로 도시 내 이용자 수요에 대한 시계열적 예측을 수행한다면 신뢰성 있는 결과 도출이 불가능하다. 특히, 2020년 초 발발한 COVID-19는 비정상적인 이동통행패턴의 변화를 불러 일으키며 시계열 수요예측을 어렵게 만들었기에 이러한 변화를 검지하고 이를 반영하여 정확한 수요를 예측 수행할 수 있는 방법론의 필요성이 대두되고 있다. 이에 본 연구는 COVID-19로 인한 비정상적 이벤트를 자동으로 검지하고 예측하는 모형 파이프라인을 구축하였다. 이는 도시 내 다양한 분야에서의 불규칙적이고 비정상적인 이벤트로 인한 수요변화가 일어나는 상황에 폭넓게 활용될 수 있을 것으로 생각된다.

• 서비스연구
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• 제13권1호
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• pp.1-26
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• 2023

본 연구는 스마트공장 도입의 효과와 관련 요인을 분석하였다. 이를 위해 도입기업과 비도입기업의 표본 데이터를 median-size-industry matching method로 각각 110개, 325개를 수집했다. 도입 전년부터 도입 후 4년도까지 재무제표 데이터(ROA 등)를 활용했는데 event study method에 따른 abnormal operating performance, annual abnormal changes를 구한 뒤 Wilcoxon signed-rank test와 t-test로 분석했다. ROA와 매출증가율은 도입 후 단기적인 효과가 나타났으나 장기적으로 이어지지는 않았다. 또한 도입효과에 인력비중, 연구개발 수준, 이전 재무 성과 세 가지 요인이 조절효과로 영향이 있는지 회귀분석을 한 결과 연구개발 수준과 이전 재무 성과의 조절효과를 확인했다. 도입 효과에 도입시기의 영향과 이와 관련된 요인으로 이전 재무 성과와 기업규모의 조절효과가 있는지 회귀분석을 한 결과 장기에 도입시기가 늦을수록 도입효과가 더 커졌고, 이전 재무 성과와 기업규모의 조절효과를 확인했다.