MR 댐퍼를 적용한 불안정판에서 하지 근력 훈련이 근 활성도에 미치는 영향 분석

최윤정,박용군,권대규,김동욱,김정자,김남균,Choi, Y.J.,Piao, Y.J.,Kwon, T.K.,Kim, D.W.,Kim, J.J.,Kim, N.G. 대한의용생체공학회 2007 의공학회지 Vol.28 No.5

Adequate postural control depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function is essential to maintain the postural control. The experimental studies was performed on the muscular activities in the lower extremities during maintaining and moving exercises on an unstable platform with Magneto Rheological(MR) dampers. The unstable platform of the developed system was controlled by electric currents to the MR dampers. A subject executed the maintaining and moving exercises which are presented through the display monitor. The electromyographies of the eight muscles in lower extremities were recorded and analyzed in the time and the frequency domain: the muscles of interest were rectus femoris(RF), biceps femoris(BF), tensor fasciae latae(TFL), vastus lateralis(VL), vastus medialis(VM), gastrocnemius(Ga), tibialis anterior(TA), Soleus(So). The experimental results showed that the muscular activities differed in the four moving exercises and the nine maintaining exercises. For the anterior-posterior pattern, the TA showed highest activities; for the left-right pattern, the TFL; for the 45, $-45^{\circ}$ pattern, the TFL and TA. Also, the rate of the increase in the muscular activities were affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggest that the choice of different maintaining and moving exercises could selectively train different muscles in various intensity. Futhermore, the findings suggested that the training using this system can improve the ability of postural control.

대학교 학생식당의 실내소음 실태 및 원인 분석 사례연구

최윤정,이선아,김혜경,Choi, Yoon-Jung,Lee, Seon-A,Kim, Hye-Kyeong 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.5

This is a case study for improving the sound environmental quality of cafeteria in university campus. The purpose of the study is to find out the present condition of physical level, type, and cause of indoor noise of cafeteria in university campus by comparison with a restaurant near campus. Research methods were field survey and questionnaire survey. Field survey was consisted of measurement on equivalent and instant noise level and observation on noise type. Respondents of questionnaire survey were 60 students using subject cafeteria or restaurant. Surveys were carried out in the 8th and in the 14th of December 2005. The results are as follows. 1) Indoor noise levels of the cafeteria were measured as $67.2{\sim}76.6$ (average 73.3) dB(A)Leq5min and $60.3{\sim}90.5$ (average 71.2) dB (A), exceeded the indoor noise recommended value of ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers). But noise levels of the restaurant were $61.6{\sim}70.4$ (average 66.9) dB(A)Leq5min and $59.8{\sim}70.6$ (average 64.9) dB(A). 2) The users's responses on major noise type in the cafeteria were 'noise by handling equipment and tableware', 'noise by moving chairs', and 'talcing noise', but 'taking noise' and 'background music' in the restaurant. 3) It was found that indoor noise level of the cafeteria was caused by sound reflection of finishing materials, noise diffusion by open type kitchen, and dragging noise of movable furniture.

학습방법개선과 후처리 분석을 이용한 자동문서분류의 성능향상 방법

최윤정,박승수,Choi, Yun-Jeong,Park, Seung-Soo 한국정보처리학회 2005 정보처리학회논문지B Vol.12 No.7

자동문서분류는 문서의 내용에 기반하여 미리 정의된 항목에 자동으로 할당하는 작업으로서 효율적인 정보관리 및 검색등에 필수적인 작업이다. 기존의 문서분류성능 향상을 위한 연구들은 대부분 분류모델 자체를 개선시키는 데 주력해왔으며 통계적인 방법으로 그 범위가 제한되어왔다. 본 연구에서는 자동문서분류의 성능향상을 위해 데이터마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처 리 방법에 의한 RTPost 시스템을 제안한다. RTPost 시스템은 학습문서 선택작업 이전에 분류항목 설정의 문제를 다루며, 분류함수의 성능보다는 지정방식의 문제점을 감안하여 학습과 분류 후처리 프로세스를 개선하려는 것이다. 이를 통해 분류결과에 중요한 영향을 미쳐왔던 학습문서의 수와 선택방법, 분류모델의 성능등에 의존하지 않는 안정적인 분류가 가능하였고, 이를 분류오류율이 높은 경계선 인접영역에 위치한 문서들에 적용한 결과 높은 정확율을 얻을 수 있었다. 뿐만 아니라, RTPost 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. Automated text categorization is to classify free text documents into predefined categories automatically and whose main goals is to reduce considerable manual process required to the task. The researches to improving the text categorization performance(efficiency) in recent years, focused on enhancing existing classification models and algorithms itself, but, whose range had been limited by feature based statistical methodology. In this paper, we propose RTPost system of different style from i.ny traditional method, which takes fault tolerant system approach and data mining strategy. The 2 important parts of RTPost system are reinforcement training and post-processing part. First, the main point of training method deals with the problem of defining category to be classified before selecting training sample documents. And post-processing method deals with the problem of assigning category, not performance of classification algorithms. In experiments, we applied our system to documents getting low classification accuracy which were laid on a decision boundary nearby. Through the experiments, we shows that our system has high accuracy and stability in actual conditions. It wholly did not depend on some variables which are important influence to classification power such as number of training documents, selection problem and performance of classification algorithms. In addition, we can expect self learning effect which decrease the training cost and increase the training power with employing active learning advantage.

클라미디아 시타시에 의한 비전형 유두 각결막염 1예

최윤정,전루민,Yun Jeong Choi,Roo Min Jun 대한안과학회 2010 대한안과학회지 Vol.51 No.4

Purpose: Only a few cases of keratoconjunctivitis caused by Chlamydophila psittaci have been reported worldwide, and no case reported in Korea. We report an atypical case of keratoconjunctivitis caused by Chlamydophila psittaci. Case summary: A 34-year-old male patient who had raised a parrot at home presented with three weeks of conjunctival injection and a week of ocular pain in his left eye. There were papillae on the left upper and lower tarsal conjunctiva and punctuate epithelial erosion of the entire cornea. He also complained of dizziness, fever, and dyspnea. Upon chest X-ray, consolidation on the right middle lobe was apparent. The Chlamydophila IgM antibody test was positive, and the pneumonia improved quickly. Nevertheless, signs of keratoconjunctivitis persisted despite 3-week treatment with oral doxycycline. As a result, the patient received an additional 10-day treatment with oral azithromycin. Four weeks after the first visit, symptoms were improving gradually, and, after six weeks, no signs of keratoconjunctivitis remained except minimal erosion. Conclusions: When patients show keratoconjunctivitis after contact with a bird, prolonged ketatoconjunctivitis by Chlamydophila psittaci should be considered. J Korean Ophthalmol Soc 2010;51(4):611-615

학교교실의 냉방시 실내열.공기환경 실태

최윤정,정연홍,이선아,김혜경,황진아,Choi, Yoon-Jung,Jeong, Youn-Hong,Lee, Seon-A,Kim, Hye-Kyeong,Hwang, Jin-A 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.4

The purpose of this study were to make clear the present condition of indoor thermal and air environment by cooling in school classrooms and to analyze the relation of the living conditions with indoor environment. The measurements on physical elements and observations on living conditions were carried out in 6 classrooms of 3 middle or high schools. Measuring elements were indoor temperature, relative humidity, PM10 and $CO_2$ concentration. As results, the averages of indoor temperature each classrooms were $24.9{\sim}26.6^{\circ}C$. Most of classrooms were lower than the Maintenance standard $(26{\sim}28^{\circ}C)$ of School Health Law. The means of relative humidity were $51.3{\sim}72%$, all classrooms were ranged within the standard $(30{\sim}80%)$. The means of PM10 concentration were $3.5{\sim}23.1{\mu}g/m^3$, all classrooms were kept within the standard $(100{\mu}g/m^3)$. The means of $CO_2$ concentration were $1218.7{\sim}4705.4ppm$, all classrooms were exceed the standard (1,000ppm). The results of analysis on relations of living conditions with the physical elements are as follow; the air conditioner set of temperature, windows and doors opening elapsed time, the number of students in classrooms and activities of students had certain effect on indoor environment.

의사결정나무 분석을 사용한 고가의료장비의 다빈도 사용 특성 분석

최윤정,곽민정,윤민,Choi, Yoon Jung,Kwak, Minjung,Yoon, Min 한국데이터정보과학회 2015 한국데이터정보과학회지 Vol.26 No.1

최근 고가의료장비의 도입으로 진단기술이 빠르게 발전하고 있으나 이에 따른 건강보험 재정의 부담이 크게 늘어 이에 대한 적절한 관리와 효율적 운영에 대한 정책이 필요하다. 이에 따라 본 연구에서는 의사결정나무분석 모형을 사용하여 CT 의료장비의 검사빈도에 영향을 미치는 요인을 파악하여 효율적 운영에 대한 방안을 제시한다. The cost of advanced medical technologies is commonly considered to be a major factor in the overall escalation of expenditures on health. The use of computed tomography (CT) scanning has increased dramatically over the past decade. CT has been rapidly adopted, despite their high cost. The aim of this study is to analysis the increasing factor of the frequency of the CT, using the decision tree model. Finally, we propose the effective policy option of diagnostic imaging technology in Korea.

대학교 신축 기숙사의 휘발성유기화합물 농도 및 새집증후군 반응

최윤정,오예슬,장윤정,김정재,Choi, Yoon-Jung,Oh, Ye-Seul,Jang, Yoon-Jeong,Kim, Jung-Jae 한국주거학회 2009 한국주거학회 논문집 Vol.20 No.6

The purposes of this study were to determine the actual state of the indoor air quality by measuring TVOC Concentration and surveying residents' responses in a newly built university dormitory and to analyze the influencing factors of IAQ. Field measurements on the concentrations of TVOC and HCHO were carried out three times at 4 week intervals in 3 rooms of a dormitory. A questionnaire survey was conducted on residents which inquired into the resident's lifestyle, their consciousness of IAQ, and the responses to SHS. According to the results, TVOC concentrations were 0.14~18.5 ppm and HCHO concentrations were 0.23~6.89 ppm during the 3 months following the completion of construction, showing a serious state in which standard levels are exceeded, though these levels seemed to decrease over time. The factors influencing the differences in the levels of TVOC and HCHO were the ventilation volume including infiltration, the heating temperature, relative humidity, or the use of living matter that include chemical ingredients. However, the residents rarely felt the symptoms of SHS and were not conscious of the importance of ventilation.

사군자탕(四君子湯) 및 사물탕(四物湯)이 methotrexate로 유도(誘導)된 흰쥐의 면역기능저하(免疫機能低下)에 미치는 영향(影響)

최윤정,김장현,Choi Yun-Jung,Kim Jang-Hyun 대한한방소아과학회 1999 대한한방소아과학회지 Vol.13 No.1

The effects of Sagunjatang and Samultang on the immunosuppression induced by methotrexate(MTX) in rats were investigated in this study. The multiple parameters of immunity assessed in each rats included leukocyte count, lymphocyte rate, the number of lymphocyte in tibial bone marrow, contact hypersensitivity to DNFB, morphological change of thymocyte and IgG antibody on SDS-PAGE. Sprague-Dawley male rats were used and divided into five groups at random. Group A was normal control. Group B, the MTX treatment control, was injected i.v. with 2mg/kg of on days 9, 11 after sensitization with SRBC on 5th day. Group C, the experimental control, was treated Sagunjatang for 18days and MTX. Group D was treated Samultang for 18days and MTX. Group E was treated Sagunjatang-Samultang for 18days and MTX. The dosage of Sagunjatang and Samultang was $1m{\ell}/day$ respectively. In the case of Group E, rats Were fed Sagunjatang $1m{\ell}$ in the morning and Samultang $1m{\ell}$ in the afternoon. The results are summarized as follows: 1. Leukocyte count in rats induced by intravenous sensitization with SRBC was decreased significantly in Group E. 2. Leukocyte counts of 2weeks later after being treated MTX were increased significantly in Groups C and D. 3. Lymphocyte rate in rats induced by intravenous sensitization with SRBC wasn't changed significantly in all the experimental groups. 4. Lymphocyte rate of 2weeks. later after being treated MTX was increased significantly in Group D. 5. The number of lymphocyte in tibial bone marrow was incereased significantly in Group C. 6. Contact hypersensitivity wasn't changed significantly in all the experimental groups. 7. Morphological finding of thymocyte in group C was similar to normal group as compared with control group. 8. Purified IgG of all the experimental groups showed two bands of 50,000 and 25,000 on SDS-PAGE. But there was no difference among experimental groups.

경계범주 자동탐색에 의한 확장된 학습체계 구성방법

최윤정,지정규,박승수,Choi, Yun-Jeong,Jee, Jeong-Gyu,Park, Seung-Soo 한국정보처리학회 2009 정보처리학회논문지B Vol.16 No.6

본 논문은 기존의 목표항목만을 위주로 한 학습체계에서 발생하는 오분류 문제의 해결을 위해 기존의 학습체계에 경계항목을 자동으로 탐 색하여 포함시켜 확대시키는 방법을 제안하고 있다. 여러 주제에 걸쳐 다양한 내용을 다루는 복잡한 문서들은 확실히 어느 범주로 분류해야 할 지 판가름하기 어려운 성질인 모호성이 강하다. 이러한 경우 모든 경우들을 정확히 구분할 수 있는 최적의 경계를 찾는 일은 더욱 어려운 일이 다. 복잡하고 불확실성이 높은 데이터들의 특징은 대부분 분류 경계영역에 위치하므로 이러한 분류경계의 데이터들을 새로운 학습 항목으로 인 식시키도록 하는 것이 필요하다. 본 연구에서는 주어진 목표항목 사이의 경계항목을 자동으로 탐색하여 학습체계에 추가하는 학습 체계 확장 알고리즘을 제시하고, 의도적인 학습오류를 발생시킨 후 기존방법과의 비교실험을 수행함으로써 제안방법의 정확성과 안정성을 비교하였다. 실 험결과 경계범주를 포함하여 학습 체계를 확장시켰을 때의 예측력은 기존 0.70에서 0.86으로 약 24% 향상 되었고, 오류를 포함시켰을 때의 예 측력은 기존 0.52에서 0.79로 약 49% 향상되었다. This paper shows a reinforced construction scheme of training data for improvement of text classification by automatic search of boundary category. The documents laid on boundary area are usually misclassified as they are including multiple topics and features. which is the main factor that we focus on. In this paper, we propose an automated exploring methodology of optimal boundary category based on previous research. We consider the boundary area among target categories to new category to be required training, which are then added to the target category sementically. In experiments, we applied our method to complex documents by intentionally making errors in training process. The experimental results show that our system has high accuracy and reliability in noisy environment.

아파트 단위주거 내부생활소음의 특성과 실태

최윤정,Choi, Yoon-Jung 한국주거학회 2009 한국주거학회 논문집 Vol.20 No.1

The present study is a preliminary research improving the dwelling quality of apartment house as a kind of multi-family housing. The purpose of the study is to find out the actual state on characteristics of indoor noise including residents' living in apartment units. The method was field survey consisted of field measurements on equivalent noise level, observation on noise type, and interview on residents' responses. Field survey were carried out in 20 occupied apartment units from January to March 2007. The results are as follows. 1) Averages of indoor noise levels including residents' living noise were measured as $43.9{\sim}62.2\;dB(A)_{Leq5min}$, the average of each house except one was higher than the permissible level, 45 dB(A). 2) The noise types observed were mostly residents' living noise and classified into 'water hammer', 'living equipment noise', 'noise by family', 'hood noise', 'kitchen noise' in own unit, 'walking and talking noise in stairs and corridors', 'noise by neighborhood house', 'noise by the upper story' in building, and outdoor noise. 3) The residents showed slightly non-positive responses at 'noise by the upper story', 'noise by neighborhood house', 'water hammer', and 'noise by family'. Therefore, it is required to plan for preventing deterioration of the dwelling quality by residents' living noise in own unit as well as by neighborhood houses.