삼상태 추론과 룰 검증이 가능한 전문가 시스템에 관한 연구

손동욱(Son Dong-Wook),박영문(Park Young-Moon),윤지호(Yoon Ji-Ho) 대한전기학회 1991 대한전기학회 학술대회 논문집 Vol.1991 No.7

소뇌교각부 비청신경초종종양 환자의 임상특성과 예후분석

손동욱 ( Dong Wook Son ),최창화 ( Chang Hwa Choi ),차승헌 ( Seung Heon Cha ) 대한뇌종양학회 2002 대한뇌종양학회지 Vol.1 No.2

Non-acoustic tumours of the cerebellopontine angle differ from vestibular schwannomas in their prevalence, clinical features, operative management, and surgical outcome. The author analysed various clinical characteristics and surgical result of 24 non-acoustic tumor of cerebellopontine angle to determine their distinctive diagnostic features, the surgical difficulties and outcomes and follow-up results. Methods:A retrospective analysis of clinical notes identified 24 patients with non-acoustic tumours of the cereelopontine angle. Data were extracted regarding presenting clinical features, histopathotogical data after surgical resection, surgical morbidity and mortatity, and clinical outcome(mean 36 months follow up). Results:The study group comprised 12 meningiomas(50%), 7 epidermoid cysts(29%), 3 trigeminal schwannom, 1 primitive neuroectodermal tumor, and 1 meastatic tumor. In patients with meningiomas, symptoms differed considerably from patients presenting with vestibular schwannomas. Cerebellar signs were present in 30% and hearing loss in only 25%. After surgical resection, normal facial nerve function was preserved in 80% of cases. For the meningioma patients, the success rate of of operation(good result) was 90%, any cranial nerve deficit was combined in 10% of patient, and the mortality was 0%. In the epidermoid group, fifth, seventh, and eighth nerve deficits were present in 100%, 14%, and 14% respectively. There were no new postoperative facial palsies. There was one perioperative death from pneumonia and meningitis and the rest(85%) showed good oucome in epidermoid patient. Overall, there were no recurrences requiring reoperation. Conclusion:Patients with non-acoustic lesions of the cerebellopontine angle often present with different symptoms and signs from those found in patients with schwannomas. Hearing loss is less prevalent. Cerebellar signs and facial paresis are more common as presenting features. Non-acoustic tumours of cerebellopontine angle can usually be resected with facial nerve preservation.

Fe-Cr-Mn-X 합금의 감쇠능 및 강도에 미치는 변태 유기 소성의 영향

손동욱(D. W. Son),강창룡(C. Y. Kang),이종문(J. M. Lee) 한국동력기계공학회 2006 한국동력기계공학회 학술대회 논문집 Vol.- No.-

This study is to improve this problem and get data about developing new alloy with high strength and damping capacity, because every machine and precision instrument bring about many problem - lowering of details and fatigue failure of parts at an early stage etc, by noise and oscillation. it get the following of conclusion. It make two specimen which add 3% Co and 1% Ti for formation of effective Nitride Layer where has high strengh at surface of. damping steel in side for improving damping capacity and make low stacking fault energy at Chemical Composition of Fe-12Cr-22Mn and also examining the damping steel apply at the parts which require wear resistance. It differ microstructure by cold working which differ amount of processing and investigate damping capacity and strength of change in proportion as change of microstructure and adding alloy element, and it get such conclusion from this experiment. two specimen all, damping capacity is strongly under the control of e martensite, but a' martensite and austenite don't have an effect on damping capacity. and, due to the specimen which add 1 % Ti has more amount of e martensite than specimen which add 3% Co, it confirm that logarithmic decrement is high.

Fe-Cr-Mn-X계 합금의 감쇠능 및 플라즈마이온질화 특성에 미치는 합금원소의 영향

손동욱(D. U. Son),정상훈(S. H. Jeong),김재환(J. H. Kim),이종문(J. M. Lee),김익수(I. S. Kim),강창룡(C. Y. Kang) 한국동력기계공학회 2005 동력시스템공학회지 Vol.9 No.1

매체의 특징에 따른 컨셉 앨범의 분류

손동욱(Dongwook Son ),이승연(Seungyon-Seny Lee) 한국콘텐츠학회 2018 한국콘텐츠학회 종합학술대회 논문집 Vol.2018 No.5

오스테나이트계 316L 스테인리스강의 강도 및 감쇠능에 미치는 미세조직의 영향

손동욱(DONG-WOOK SON),이종문(JONG-MOON LEE),김효종(HYO-JONG KIM),남기우(KI-WOO NAM),박규섭(KYU-SEOP PARK),강창룡(CHANG-YONG KANG) 한국해양공학회 2006 韓國海洋工學會誌 Vol.20 No.1

The effects of microstructure on the damping capacity and tensile properties of 316L stainless steel were investigated. Increasing the degree of cold working, the volume fraction of ε-martensite decreased after rising to maximum value at specific level of cold working, the volume fraction of α'-martensite slowly increased and then dramatically increased from the point of decreasing ε-martensite volume fraction. Increasing the degree of cold working, the behavior of damping capacity is similar to that of the ε-martensite. After the damping capacity showing the maximum value at about 20% of cold rolling, damping capacity was decreased with the volume fraction of ε-martensite. Tensile strength was proportional to the volume fraction of α'-martensite, and elongation steeply decreased in the range low volume fraction of α'-martensite, then slowly decreased in range the above 10% volume fraction of α'-martensite. The damping capacity and elongation is strongly controlled by the volume fraction of ε martensite with liner relationship. However, the effect of the volume fraction of α'-martensite and austenite phase on the damping capacity was not observed. Tensile strength was governed by the volume fraction of α'-martensite.

초등학교 고학년의 유튜브 이용동기가 스마트미디어 과의존을 매개하여 학교생활적응에 미치는 영향: 성별 차이를 중심으로

손동욱 ( Son Dong Wuk ),임선아 ( Lim Sun Ah ) 한국초등교육학회 2020 초등교육연구 Vol.33 No.3

본 연구는 초등학교 고학년 학생들의 유튜브 이용동기와 학교생활적응 간의 관계에서 스마트미디어 과의존의 매개효과를 검증하고 이러한 변인간 관계가 성별에 따라 다르게 나타나는지 검증하고자 하였다. 이를 위해 전국의 초등학교 5,6학년 1,239명의 남·녀 학생 자료를 구조방정식모형(SEM)과 다집단 구조방정식모형 분석 방법을 사용하여 분석하였다. 그 결과는 다음과 같다. 첫째, 유튜브 이용동기의 유형은 스마트미디어 과의존과 학교생활적응에 다르게 영향을 미치고 있었다. 즉, 유튜브 이용동기의 관계추구, 재미추구 동기는 스마트미디어 과의존에 정적 영향을 주지만 정보추구 동기는 스마트미디어 과의존을 낮추고, 학교생활적응에 긍정적 영향을 주는 것으로 나타났다. 둘째, 유튜브 이용동기와 스마트미디어 과의존, 학교생활적응 변인들 간의 경로와 경로값이 성별에 따라 다르게 나타났다. 구체적으로, 남학생들과 달리 여학생의 경우 관계추구 동기는 스마트미디어 과의존을 매개하여 학교생활적응에 부정적인 영향을 미치는 것으로 나타났다. 본 연구의 시사점은 다음과 같다. 초등학생들이 양질의 콘텐츠를 활용할 수 있도록 미디어 이용에 대한 판단력을 기르는 미디어 리터러시 교육이 필요함을 시사한다. 또한 여학생들의 스마트미디어 과의존에 따른 학교생활부적응에 대한 접근에서 관계적 이해를 바탕으로 접근해야 한다는 점을 시사하고 있다. The purpose of this study was to verify the mediating effect of smart media overdependence between YouTube use motivation and school life adaptation, and to verify whether these relationships among variables appear differently by gender. To this end, this study analyzed using SEM multi-group analysis with 1,239 student data from 5th and 6th graders nationwide. The results were as follows. First, the motivation for pursuing relationships and pursuing fun for YouTube had a positive effect on the dependency on smart media, but the motivation for pursuing information lowered the dependency on smart media and positively affected school life adaptation. Second, there was a difference according to gender difference in the paths between YouTube usage motivation, smart media overdependence, and school life adaptation variables. Specifically, in the case of girls, the motivation for pursuing relationships was negatively affecting their adjustment to school life by mediating dependency on smart media. This study suggests that media literacy education is necessary for elementary school students to develop self-control over media use and to develop judgment to use quality content. In addition, it suggests that girls' access to school life maladjustment due to the dependence on smart media should be approached based on understanding about girls’ relationship needs.

Fe-Al Mn 합금의 진동감쇠능 및 인장성질에 미치는 미세조직의 영향

손동욱(D.U. Son),김재환(J.H. Kim),이종문(J.M. Lee),김익수(I.S. Kim),김한청(H.C. Kim),강창룡(C.Y. Kang) 한국동력기계공학회 2004 동력시스템공학회지 Vol.8 No.4

오스테나이트계 스테인리스강의 강도 및 감쇠능에 마치는 미세조직의 영향

손동욱(D. U. Son),김재환(J. W. Kim),이종문(J. M. Lee),강창룡(C. Y. Kang) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-

The effect of the phases of v, α' and ε martensite, which constitute the structure of the 316L stainless steel with austenite structure at room temperature, on the damping capacity and tensile properties has been investigated. Various fraction of these phases were formed depending on the cold work degree, namely the volume fraction of ε martensite showed maximum value about at 20% cold rolling. while the volume fraction of α' martensite continuously rose according to the increase of cold rolling. The behavior of damping capacity with increasing the degree of cold rolling is the same as that of E martensite. The maximum value of damping capacity showed near at 20% cold rolling formed the largest volume fraction of ε martensite phase. With increasing the volume fraction of α' martensite, tensile strengths increased and elongation decreased due to the increment in the volume fraction of martensite induced by deformation. The damping capacity and elongation is strongly controlled by the volume fraction of E martensite with liner relationship. however, the effect of damping capacity on the volume fraction of α' martensite and austenite phase was not observed. while, tensile strength was controlled by the volume fraction of α' martensite.

원위 대퇴골 골절에서 슬관절 강직의 위험 인자

손동욱 ( Dong-wook Son ),김형수 ( Hyoung-soo Kim ),최우영 ( Woo-young Choi ) 대한골절학회 2018 대한골절학회지 Vol.31 No.4

목적: 원위 대퇴골 골절을 근육 아래 잠김 금속판을 이용하여 치료한 환자에서 발생하는 슬관절 강직의 위험 인자에 대해 조사하고 임상적 방사선적 결과에 대해 분석하고자 한다. 대상 및 방법: 본 연구는 후향적 환자 대조군 연구로 슬관절 강직의 환자군은 수술 후 12개월의 관절 운동 범위가 90도 이하 혹은 마취하 관절 수동술을 시행 받은 환자이고 대조군은 정상 관절 운동 환자였다. 발생 가능한 위험인자의 빈도를 단변량 및 로지스틱 회귀 분석을 이용하여 분석하였다. 결과: 환자군 14예, 대조군 40예로 54예의 환자가 연구에 포함되었다. 단변량 분석상 분쇄골절, 관절내 골절, 개방성 골절, 일시적 외고정 장치, 심한 퇴행성 관절염 및 장기간의 부목 고정이 슬관절 강직의 위험 인자였다. 하지만, 다중 회귀 분석상에서는 신전기전의 손상이 유일한 위험 인자였다 (p=0.001; odds ratio, 42.0; 95% confidence interval, 5.0- 350.7). 결론: 원위 대퇴골 골절에서 슬관절 강직을 발생시킬 수 있는 위험 인자들을 정확히 알고 있다면 슬관절 강직 예방에 도움이 될 것으로 생각된다. 특히 슬개골 골절이나 대퇴 사두근의 개방성 손상과 같은 신전 기전의 손상은 슬관절 강직을 독립 적으로 예측할 수 있는 주요 위험 인자이다. Purpose: The aims of this study were to evaluate risk factors for knee stiffness after the fixation of distal femoral fractures, and to analyze the clinical and radiologic outcomes. Materials and Methods: This is a retrospective case control study of 104 consecutive patients who have a distal femoral fracture and were treated with a submuscular locking plate. The case group comprised of patients with 12-month postoperative range of motion (ROM) ≤90° or a history of manipulation under anesthesia. The case group was compared with the control group of patients with a 12-month postoperative ROM >90°. The possible risk factors were evaluated by univariate and logistic regression analysis. The postoperative ROM and Knee Society clinical rating system was evaluated for the clinical assessment and the distal femoral angle on a whole-extremity scanogram was measured for radiologic assessments. Results: Fifty-four patients were included in the study (14 in the case group, 40 in the control group). Univariate analysis showed that comminuted fracture, intra-articular fracture, open fracture, temporary external fixation, severe osteoarthritis, and prolonged immobilization placed patients at an increased risk for knee stiffness. On the other hand, multivariate logistic regression showed that an extensor mechanism injury was the only significant predictor (p=0.001; odds ratio, 42.0; 95% confidence interval, 5.0-350.7). The ROM and Knee Society score were significantly lower in the case group; however, the coronal alignment was similar in the case and control group. Conclusion: Various factors that delay postoperative knee motion place patients at increased risk of knee stiffness. Understanding these risk factors may help surgeons prevent postoperative knee stiffness after distal femoral fractures. In particular, extensor mechanism injury, such as patella fracture or open quadriceps injury, was found to be an independent predictable factor associated with knee stiffness.