탄성력이 관계되는 역학적 에너지 보존에 관한 지도상의 문제점과 개선 방안

문충식,윤성현,권재술 한국교원대학교 과학교육연구소 1991 청람과학교육연구논총 Vol.1 No.1

현행 고등학교 물리 교과서와 대학 일반물리학 교재에 나타난 용수철 진자의 진동에서 역학적 에너지 보존에 관한 기준점 설정의 불명확성과 오해의 소지를 지적하고 이를 해결하기 위한 방안을 제시하였다. 혼란이 생기는 원인은 근본적으로 좌표 기준, 위치 에너지의 기준 설정에서 나타나는 것으로써 군등장인 경우, 거리에 비례하는 위치 에너지(mgx)이므로 기준을 어디에 잡아도 무방하나 그렇지 않는 탄성 위치 에너지의 경우(1/2)kx^2에는 주의를 요한다. 본 연구는 기준 위치 설정에 따라 위치 에너지 표현식이 다름을 보이고 이를 고등학교 및 대학 일반물리학 수준에서 지도할 수 있는 방안을 제시하고자 한다. A typical representation of elastic potential energy is (1/2)kx^2, where x represents the distance from the spring's unstratched end point. However, this representation will be correct only in a particular situation that the origin of the coordinate and the reference point of the potential energy are at x=0. Without this condition, the potential representation, (1/2)kx^2, is no longer correct. In this study, the misconceptions found in high school textbooks and university laboratory manual were exemined and presented a improved method to teach elastic potential energy. The generalized form of elastic potential energy with arbitrary reference point in coordinate system as well as potential energy was derived. To adopt this idea in high school level, a graphical method of deriving the generalized form of elastic potential energy was devised.

관성력 수업에서 대학생들의 인지 갈등과 개념 변화와의 관계

권재술,문성숙 한국교원대학교교육연구원 2006 敎員敎育 Vol.22 No.4

망간 노출 근로자의 정신 ·신경행동 양상에 영향을 주는 요인

문영한,권기련,김은아,김규상,김양호,김재우,노재훈,양정선,진영우 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.2

The risk posed to human health by environmental manganese (Mn) exposure is unknown. The purpose of this study is to establish if subclinical effects related to Mn exposure and examine the factors influencing psychoneurobehaviral outcomes of Mn exposed workers. This study involved 121 male workers of welding, alloy furnace, and manufacturing of welding stick. Study investigations include: a questionnaire covering demographic characteristics, job and exposure history and medical symptoms and conditions, monitoring workplace air for personal exposure to respirable and inhalable manganese, analysis of blood and urine samples, psychoneurobehaviral test(neurobehaviral core test battery(NCTB), signal change on magnetic resonance imaging (MRI) scans, minimental state and neurological examination). The main results of this study were as follows; 1. Preliminary results showed that, with increasing manganese exposure, neurobehaviral performance was poorer and signal change on MRI scans increased. 2. The results of examination revealed significant relations on psychoneurobehaviral outcomes (neurobehaviral performance, signal change on MRI scans, and neurological features). 3. In multiple regression, age and educational status as demographic variables and exposure level were significantly related to neurobehaviral test. Also exposure level and serum Mn concentrations were positively related to signal change on MRI scans and neurological features affected by Mn on the brain (signal change). 4. Psychoneurobehaviral outcomes from Mn exposure were related to neurobehaviral performance, signal change on MRI scans, neurological features and profile of mood states (POMS), and influenced positively with age, alcohol and smoking history, and duration of Mn exposure, negatively with educational status. Serum Mn concentrations in combination with brain MRI scans, and perhaps a battery of neurobehaviral tests, appear to be the best way to monitor excessive exposure to Mn. These results are consistent with our knowledge on Mn action on the brain and are similar to the type of neurobehaviral dysfunction. They suggest that there may be age, educational status, and life style (alcohol and drinking history) differences with chronic environmental exposure. These findings suggest further evaluation, particularly on relationships between Mn exposure, aging, and susceptibility factors.

광촉매를 이용한 셀룰로오스섬유의 기능화에 관한 연구 : 항균·소취성 및 자외선 차폐성을 중심으로 Focusing on Antibacterial activity, Deodorization & UV cut ability

권오경,문제기,손부헌,최영희 한국의류산업학회 2003 한국의류산업학회지 Vol.5 No.4

In this study, we measured the antibacterial activities, deodorization, UV cut ability, whiteness and SEM, according to the size(5 μm, 15 ?m) of ThiO₂, concentration(3%, 5%, 10%) and dipping temperature(50℃, 70℃) with using anatase type of TiO₂ photocatalyst. Photocatalyst is the substance which carries out functions, such as decomposition, removal, deodorization, antibacterial, etc. of a contaminant, in a place with light based on an oxidation-reduction reaction. The results of this study were as follow. Antibacterial activities are increased with increasing of the TiO₂'s concentration, and TiO₂ has high antibacterial activities for Staphylococcus aureus but it has low antibacterial activities for Klebsiella pneumoniae. The deodorization and UV cut ability is very good, therefore be able to get good effects with usingonly 3% of TiO₂. Every effects are increased by using small size of TiO₂ and high dipping temperature.

부정교합 아동의 성장에 따른 연조직 측모의 변화

권오원,경희문,장병천,성재현,김정민 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.3

This investigation was undertaken to know how soft tissue facial profile could changed with age. The 3 serial lateral cephalometric roentgenograms of the twenty nine boys and twenty six girls between 9 and 13 years of age were studied and the findings seemed to warrant the following conclusions. 1. The author made the tables of means, standard deviations in each item, sex, age. 2. Soft tissue facial angle, soft tissue facial convexity including the nose tended to increase, but others tended to remain relatively stable. 3. Facial soft tissue thickness increased with age and the growth of facial soft tissue in the middle rgion (point A, LS, LI)was greater than others in the facial region. 4. In the soft tissue vertical proportions, GI'-Sn/Sn-Me' was 1.1, Sn-St/St-Me' was 0.51:1, Sn-LI/LI-Me' was 0.82.1 and those were stable with age.

알쯔하이머 환자의 실행증 오류 형태

권재철,나덕렬,김향희,김경문,강연욱 대한신경과학회 1997 대한신경과학회지 Vol.15 No.5

경부에 발생한 의인성 괴사성 근막염의 증례

문철,권혁도,이동근,박경옥,성길현,이재은 大韓顎顔面成形再建外科學會 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.1

Necrotizing fascitis is a severe soft tissue infection characterized by extensive necrosis of superficial fascia, suppurative fascitis, vascular thrombosis, widespread undermining of surrounding tissues. Accociated systemic problems are widespread undermining of surrounding tissues, Accociated systemic problems are common, with chronic alcoholism and diabetes being most prominent. Most commonly this disease presents in the extremities, trunk, and perineum. Necrotizing fascitis of dental origing is rare and its fulminating clinical course is not well documented in the dental literature. The present report is a case of necrotizing fascitis following vital extirpation of the pulp in a patient with uncontrolled diabetes mellitus and liver cirrhosis. Originally throught to be caused by hemolytic streptococcus organism or stphylococcus aureus, advances in anaerobic culturing have shown it to be a synergistic bacterial infection involving aerobic and ovligate anaerobes. it is relatively rare in relatively rare in haea and neck regions. If it was not diagnosed and treated in early stages, necrotizing fascitis can be potentially fetal, with a mortality rate approaching 40%. It's treatment requires early recognition, prompt and aggressive surgical debriment and proper supportive cares, such as, antibiotic therapy, fluid resuscitation and correction of metabolic and electrolyte disorder, resolving of the underlying systemic disease. Recently, we experienced two cases of necrotizing fascitis in cervicofacial region, One patient was 60 years old male with uncontrolled Diabetes Mellitus and other patient was 48 years old with steroid therapy during 30 years. Local surgical wound healing was successful but, patients were died after admission, because of lung abscess, gastrointestinal bleeding, septic shock and respiration hold.

경북대학교 병원 교정과에 내원한 부정교합 환자의 분포 및 변동추이

권오원,경희문,곡덕부,성재현,박동옥 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.3

1795 patients who visited orthodontic department from 1979 to 1987, were surveyed on the yearly tendency of patient distribution and state of Angle's classification. The results were as follows: 1. There was increased visiting rate of patient per year and higher visiting rate in female than in male. 2. 8-15 age group was 70.3% in total visiting patients and over 20 age group was 10.8%, under 7 age group was 7.3%. 3, Class I malocclusion was 26.3%, Class II div 1 was 31.0%, Class II div 2 was 1.6% and Class III was 41.1% in total visiting pateint. 4. There was increased tendency to be received preventive treatment than fixed treatment and increased extracting rate per year in fixed treatment. 5. There was increased tendency for the number of the patient to be received orthognathic surgery.

초음파 펄스에코 데이터 기반 3차원 시각화 방법론

권정현,장홍래,성제중,안형근,장순재,송문호 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

The nondestructive testing using ultrasonic pulse-echo data is an effective test methodology esperially for metal structure. Typically, the ultrasonic pulse-echo data is processed and the results are shown in A-scan, B-scan or C-scan formats. Upon viewing B-scan and C-scan data the viewer is able to identify the location of faults as well as their rough dimension. In this paper, we evaluate the applicability of various 3-D visualization methods frequently used in medical imaging, namely, surface rendering (SR), volume rendering (VR) and maximum intensity projection (MIP), for nondestructive testing purposes. Such 3-D visualization of ultrasonic pulse-echo data enables easier identification of the location and dimension of faults more accurately.

중대산업사고 예방을 위한 종합위험관리체제(IRMS) 구축에 관한 연구

권혁면,성대현,김재현,임대식,김기영,편무욱,문일,고재욱,이영순,윤인섭 한국안전학회 2003 한국안전학회지 Vol.18 No.3

The Process Safety Management (PSM) by the Law of Industry, Safety and Health has been performed for preventing major accidents of chemical plants since 1996. In terms of preventing chemical accidents more precisely, it is essential to develop a tool for quantitative risk assessment. For this, KOSHA (Korea Occupational Safety and Health Agency) developed an Integrated Risk Management System (IRMS) . The system is designed to assimilate data on chemical plant hazards from external database, to integrate these data with location information (topographic and demographic), and to make them user-friendly accessible. The system consists of several main functions: display of five major Korean petrochemical complex layout, display of equipment layout with its information utilizing the external database, zonation of the hazard effected area with consequence analyses, the most probable accident scenario generation, accident/incident database and calculation of frequency of accident using equipment reliability database, etc. The highlight of IRMS is to provide the risk contours using GIS(Geographical Information System) technology. IRMS is intended to manage hazardous installation more systematically and effectively, to reduce the number of accident remarkably, further minimizing production loss in the plant. The system is now under application to about 500 PSM sites as well as and emergency authorities in Korea by KOSHA (Korea Occupational Safety and Health Agency)