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.

아파트 개조 전후의 휘발성유기화합물 농도변화 실태

최윤정,심현숙,신해철,Choi, Yoon-Jung,Shim, Hyun-Suk,Shin, Hae-Chul 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.4

The purposes of this study were to make clear the present condition of the TVOC and HCHO concentration after renovation in apartment houses. The field measurements of TVOC and HCHO concentration according to the Korea Test Method Standard for Indoor Air Quality were carried out in 4 subject apartment houses. The results are as follows; the TVOC concentration after renovation in apartment houses ranged from mean 0.35ppm to mean 5.08ppm and increased of $0.35{\sim}5.08ppm$. The TVOC concentration of 3 subjects exceeded the Indoor Air Quality Management standard for the newly-built apartment houses (0.58ppm). The HCHO concentration after renovation ranged from mean 0.13ppm to mean 0.43ppm and increased of $0.06{\sim}0.26ppm$. The HCHO concentration of 2 subjects exceeded the Standard (0.17ppm). As results of analysis on the relation of concentrated ascension and renovation elements, the amount and the types of finishing materials and adhesives affected concentrated ascension. Also, production method for installed or purchased furniture had certain effect on the TVOC and HCHO concentration ascension.

Comparison of the mechanical properties and microstructures of fractured surface for Co-Cr alloy fabricated by conventional cast, 3-D printing laser-sintered and CAD/CAM milled techniques

최윤정,곽재영,허성주,김성균,안진수,박동수,Choi, Yun-Jung,Koak, Jai-Young,Heo, Seong-Joo,Kim, Seong-Kyun,Ahn, Jin-Soo,Park, Dong-Soo The Korean Academy of Prosthodonitics 2014 대한치과보철학회지 Vol.52 No.2

연구 목적: 본 연구의 목적은 주조, 3-D printing laser sintered 및CAD/CAM technology를 이용한 milling 방법으로 제작된 치과용 코발트-크롬 합금의 기계적 물성을 비교하고 파절 단면의 미세 구조를 살펴보는 데 있다. 이를 통해 새롭게 소개된 제작 기법 - 3D-printing laser sintered - 이 치과용 합금 제작으로 적합한 지 알아보고자 한다. 연구 재료 및 방법: 36개의 flat disc 모양의 시편을 제작하여 제작 방법에 따라 세 집단으로 나누었다; 주조 방식으로 제작한 12개, laser sintering 방법으로 12개, CAD/CAM milling 방법으로 12개의 시편을 제작하여 표면 경도 시험을 시행하였다. 또한 각 집단 별로 12개의 dumbbell 모양의 시편을 제작하여 인장 강도 시험을 시행하였다. 통계량이 비모 수적 통계 분포를 보였으므로 Kruskal-Wallis 검정을 이용하여 각 실험군의 인장 강도 시험 결과를 비교했으며, 통계적 유의 수준은P=.05로 설정하여 Mann-Whitney 및 Bonferroni 사후 검정을 시행하였다. 전자 주사 현미경을 사용하여 파절 단면의 미세 구조를 관찰하였다. 결과: Vickers hardness test에서 세 집단간에 모두 유의한 차이가 있었고, 주조 방식으로 제작된 실험군에서 가장 큰 표면 경도(455.88 Hv)가, CAD/CAM milling으로 제작된 실험군에서 가장 낮은 표면 경도(243.40 Hv)를 나타냈다. 최대 인장 강도, 0.2% 항복강도, elongation 및 elastic modulus에서 세 집단간에 모두 유의한 차이가 나타났으며, CAD/CAM milling으로 제작한 실험군에서 가장 높은 최대 인장 강도(1442.94 MPa)가, laser sintered 실험군에서 가장 큰 0.2% 항복 강도(1136.15 MPa)가 나타났다. 파절 단면의 전자 주사 현미경 관찰 결과, 주조 시편에서는 독특한 성긴 모양과 전형적인 주조 다공성 구조가 관찰되었고, laser sintered 시편에서는 편평한 면을 동반한 거친 결정 구조가, 그리고 milled 시편에서는 균일하고 규칙적인 치밀 미세 구조가 나타났다. 결론: 서로 다른 제작 방법은 코발트-크롬 합금의 물리적 성질과 파절 단면의 미세 구조에 영향을 미쳤다. 주조 방식으로 제작된 시편에서 가장 큰 표면 경도가, milling으로 제작된 시편에서 가장 큰 인장 강도를 나타냈으며, 본 연구의 모든 실험군에서 치과용 합금의 ISO 기준에 부합하는 물성을 보였다. Purpose: The purpose of present study is to compare mechanical properties and microstructural characteristics of fractured surface for cast, 3-D printing laser sintered and CAD/CAM milled cobalt-chromium (Co-Cr) alloy specimens and to investigate whether laser sintered technique is adequate for dental applications. Materials and methods: Thirty six flat disc shape Co-Cr alloy specimens were fabricated for surface hardness test and divided into three groups according to the manufacturing methods; 12 specimens for casting (n=12), 12 specimens for laser sintered technology (n=12) and 12 specimens for milled technology (n=12). Twelve dumbbell shape specimens for each group were also fabricated for a tensile test. Statistical comparisons of the mechanical properties for the alloys were performed by Kruskal-Wallis test followed by Mann-Whitney and Bonferroni test. The microstructural characteristics of fractured surfaces were examined using SEM. Results: There were significant differences in the mean Vickers hardness values between all groups and the cast specimen showed the highest (455.88 Hv) while the CAD/CAM milled specimen showed the lowest (243.40 Hv). Significant differences were found among the three groups for ultimate tensile strength, 0.2% yield stress, elongation, and elastic modulus. The highest ultimate tensile strength value (1442.94 MPa) was shown in the milled group and the highest 0.2% yield strength (1136.15 MPa) was shown in the laser sintered group. Conclusion: Different manufacturing methods influence the mechanical properties and microstructure of the fractured surfaces in Co-Cr alloys. The cast Co-Cr alloy specimens showed the highest Vickers hardness, and the CAD/CAM milled specimens revealed the highest tensile strength value. All alloys represent adequate mechanical properties satisfying the ISO standards of dental alloy.

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.

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.

아파트 단위주거의 리모델링 요소와 현황 - 인테리어디자인업체 실무자와 거주자 심층면접을 통하여 -

최윤정,심현숙,정연홍,Choi, Yoon-Jung,Shim, Hyun-Suk,Jeong, Youn-Hong 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.6

The purpose of this study was to grasp major elements and actual condition of apartment unit remodeling by in-depth interviews on residents and specialists. The interviews had been conducted to interior designers who have a wide experience of apartment remodeling and residents who live in recently remodeled apartment unit. In-depth interview is a kind of qualitative method in which attention to reply of responses with open-access between interviewer and respondents. According to the results, remodeling elements were generally changing of lighting fixtures and finishing materials in the all spaces, integration of balcony into children's room, installation of furniture in kitchen and entrance, changing storage furnitures and equipments in bathroom. Artificial lighting method were selected generally whole lighting. Finishing materials were used ordinary (non environmentally-friendly) wallpaper and adhesion and tempered floor. There were unsatisfied factors after remodeling, these were dissatisfaction of design, construction defects, and stink of reflecting 'sick house'. Also they responded that they should be considering to use environmentally-friendly material at next remodeling.

상향식 계층분류의 최적화 된 병합을 위한 후처리분석과 피드백 알고리즘

최윤정,박승수,Choi, Yun-Jeong,Park, Seung-Soo 한국정보처리학회 2010 정보처리학회논문지B Vol.17 No.2

본 논문은 자동화된 분류시스템의 성능향상을 위한 것으로 오분류율이 높은 불확실성이 강한 문서들의 범주결정방식을 개선하기 위한 후처리분석 방법과 피드백 알고리즘을 제안한다. 전통적인 분류시스템에서 분류의 정확성을 결정하는 요인으로 학습방법과 분류모델, 그리고 데이터의 특성을 들 수 있다. 특성들이 일부 공유되어 있거나 다의적인 특성들이 풍부한 문서들의 분류문제는 정형화된 데이터들에서 보다 심화된 분석과정이 요구된다. 특히 단순히 최상위 항목으로 지정하는 기존의 결정방법이 분류의 정확도를 저하시키는 직접적인 요인이 되므로 학습방법의 개선과 함께 분류모델을 적용한 이후의 결과 값인 순위정보 리스트의 관계를 분석하는 작업이 필요하다. 본 연구에서는 경계범주의 자동탐색기법으로 확장된 학습체계를 제안한 이전 연구의 후속작업으로써, 최종 범주를 결정하기까지의 후처리분석 방법과 이전의 학습단계로 피드백하여 신뢰성을 높일 수 있는 알고리즘을 제안하고 있다. 실험결과에서는 제안된 범주결정방식을 적용한 후 1회의 피드백을 수행하였을 때의 결과들을 단계적이고 종합적으로 분석함으로써 본 연구의 타당성과 정확성을 보인다. This paper shows a reinforcement post-processing method and feedback algorithm for improvement of assigning method in classification. Especially, we focused on complex documents that are generally considered to be hard to classify. A basis factors in traditional classification system are training methodology, classification models and features of documents. The classification problem of the documents containing shared features and multiple meanings, should be deeply mined or analyzed than general formatted data. To address the problems of these document, we proposed a method to expand classification scheme using decision boundary detected automatically in our previous studies. The assigning method that a document simply decides to the top ranked category, is a main factor that we focus on. In this paper, we propose a post-processing method and feedback algorithm to analyze the relevance of ranked list. In experiments, we applied our post-processing method and one time feedback algorithm to complex documents. The experimental results show that our system does not need to change the classification algorithm itself to improve the accuracy and flexibility.

증식성 근막염의 세침흡인 세포학적 소견

최윤정,이상엽,양우익,정순희,이광길,Choi, Yoon-Jung,Yi, Sang-Yeop,Yang, Woo-Ick,Jung, Soon-Hee,Lee, Kwang-Gil 대한세포병리학회 1993 대한세포병리학회지 Vol.4 No.1

Proliferative fasciitis is a benign pseudosarcomatous mesenchymal lesion occurring in the subcutis. The lesion occurs clinically as a tumorous mass that develops within a rather short time in elderly patients. We recently experiecened a case of fine needle aspiration cytology of proliferative fasciitis in the left anterior chest wall of a 72 year-old male patient. The smear revealed two types of cells. One was the large and mostly oval cell with one or two nuclei lying at the periphery of the cell body and abundant basophilic cytoplasm like the ganglion cell. The nuclei were round to oval, had vesicular chromatin and contained prominent nucleoli. The other was the spindle shaped fibroblast with an oval nucleus. The differential diagnosis includes a true tumor such as ganglioneuroma, rhabdomyosarcoma, and liposarcoma and therefore fine needle aspiration cytology is very much indicated in order to exclude these possibilities.

정보화시대를 대비한 화학공학 데이터베이스

최윤정,양대륙 ( Y . J . Choi,D . R . Yang ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

요양병원 간호인력의 병원감염관리 지식이 병원감염관리 수행에 미치는 영향: 건강신념의 매개효과

최윤정,Choi, Yun-Jung 한국디지털정책학회 2021 디지털융복합연구 Vol.19 No.7

본 연구는 요양병원 간호인력을 대상으로 병원감염관리 지식과 병원감염관리 수행 간의 건강신념의 매개효과 확인하기 위해 실시되었다. 부산 소재 5개 요양병원에 근무하는 간호사, 간호조무사를 대상으로 연구하였으며, 최종적으로 212부의 설문지를 이용하여 SPSS 25.0, SPSS Procee Macro를 통해 분석하였다. 연구결과, 병원감염관리 지식은 병원감염관리 수행에 유의미하였고(B=2.90, p<.001), 건강신념의 영향력도 유의미하게 나타났다(B=.52, p<.001). 병원감염관리 지식은 병원감염관리 수행에 직접적인 영향을 미치며, 건강신념을 통해서도 간접적으로 병원감염관리 수행에 영향을 미치는 것으로 나타나 부분매개효과를 확인하였다. 본 연구는 요양병원에 근무하는 간호사, 간호조무사가 인지하는 병원감염관리 지식이 병원감염관리 수행에 미치는 영향에 있어 건강신념의 매개효과를 확인함으로써 요양병원 간호조직의 효과적인 병원감염관리를 수행함에 필요한 기초자료를 제공함에 그 의의가 있다. This study was conducted on nursing staff at care hospitals to confirm the mediating effect of health beliefs between the knowledge of nosocomial infections management and the execution of nosocomial infections management. This study was carried out on nurses and assistant nurses working at five care hospitals located in Busan, and finally 212 questionnaires were analyzed through SPSS 25.0 and SPSS Procee Macro. The results of the study showed that knowledge of nosocomial infections management is significant in the execution of nosocomial infections management(B=2.90, p<.001), and the influence of health beliefs was shown to be significant as well(B=.52, p<.001). Knowledge of nosocomial infections management has a direct effect on the execution of nosocomial infections management, and was also shown to have an indirect effect on the execution of nosocomial infections management through health beliefs, confirming partial mediating effects. This study is significant in that it provides the baseline data necessary for the effective execution of nosocomial infections management of nursing organizations in care hospitals by verifying the mediating effects of health beliefs in terms of the effects of knowledge of nosocomial infections management perceived by nurses and assistant nurses working in care hospitals on the execution of nosocomial infections management.