헬름홀츠 코일을 이용한 강자성체의 와전류검사

성제중,서동만,신용훈,엄태건,서동섭 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

Ferromagnetic material like the steel tubes can easily distort eddy current testing signal due to increased magnetic permeability for defects. Because magnetic field of the test probe is affected in an inconsistent way when the material under the testing has permeability. This permeability effect can be reduced by magnetic saturation. In this paper eddy current testing system was developed to detect flaws on the steel tubes. Magnetic saturation probe with helmholtz coil was designed for saturation and inspection of the steel tubes. When using the designed test probe, the relationship between flaw signals and noises was obviously discriminated. Additionally, a high pass filter was included in the eddy current board to minimize noises due to DC magnetic field.

전산유체 기법을 이용한 용존공기부상법에서의 접촉도 조건변화에 따른 충돌효율평가

김성훈,유제선,박희경 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

Dissolved air flotation (DAF) is a solid-liquid separation process that uses fine rising bubbles to remove particles in water. Most of particle-bubble collision occurs in the DAF contact zone. This initial contact considered by the researchers to play a important role for DAF performance. It is hard to make up conceptual model through simple mass balance for estimating collision efficiency in the contact zone because coupled behavior of the solid-liquid-gas phase in DAF system is 90 complicate. In this study, 2-phase(gas-liquid) flow equations for the conservation of mass, momentum and turbulence quantities were solved using an Eulerian-Eulerian approach based on the assumption that very small particle is applied in the DAF system. For the modeling of turbulent 2-phase flow in the reactor, the standard k-ε mode Ⅰ(liquid phase) and zero-equation(gas phase) were used in CFD code because it is widely accepted and the coefficients for the model are well established. Particle-bubble collision efficiency was calculated using predicted turbulent energy dissipation rate and gas volume fraction. As the result of this study, the authors concluded that bubble size and recycle ratio play important role for flow pattern change in the reactor. Predicted collision efficiency using CFD showed good agreement with measured removal efficiency in the contact zone. Also, simulation results indicated that collision efficiency at 15% recycle ratio is higher than that of 10% and showed increasing tendency of the collision efficiency according to the decrease of the bubble size.

인조 합성 테니스 바닥재의 지면 반력 분석

조승제,정미라,서국웅,박승범,윤양진,이훈식,강영택 釜山大學校 附設 體育科學硏究所 1998 體育科學硏究所 論文集 Vol.14 No.-

Some authors suggest that certain types of surfaces are the origin of such injuries. A few years after the first medical concerns about surfaces were voiced, publications of biomechanical measurements apperared, describing accleration, force, and impact measurement on different types of surfaces. In many sport activities, surfaces can be under very high dynamic load. This was the reason for the development of various methods for impact simulation, like the development of various methods for impact simulation, like the artificial athlete. Furthermore, it is important to collect information about the hardness of new and already existing surfaces in sport arenas. The idea on which this measuring system is based Is as follows: The stiffness of the material can be computed from the kinematics measurd at touch down of a rigid body onto a material sample. The results show the following The result for the artifical surfaces(Synpave ace) is surprising. It is known that these surfaces are much harder than synpave rebound classic, synpave spring. This finding suggests that it may be possible that the subjective impression is used as one criterion in the selection of landing(or style) strategies. The number of subjects in this experiment is too small to make statistically significant conclusions. It is shown analytically that when an object a deformable surface, the acceleration it experiences is inversely propotional to its mass. In future, it need to stress that the interaction between shoe and surface is important, and this aspect has now become well accepted. Considering biomechanical aspect in player's injury, it request Korean Standards for synthetic playing surfaces in sport like ASTM(America Society for Testing & Materials) standards of America, DIN 18035 standards of Germany, BSI standards of U.K.

급성 림프구성 백혈병 환자에서 발생한 침습성 국균 심내막염 2예

신성철,백경란,정재홍,송봉근,김동희,전경만,채제욱,손준성,정숙인,오원섭,송재훈 대한감염학회 2003 감염과 화학요법 Vol.35 No.5

국균은 호흡기를 통해 유입되며 심한 면역기능저하 환자에서 기회감염을 일으키는 진균이며 주로 혈관을 따라 폐를 침범하고 심장과 골침범은 매우 드문 것으로 알려져 있다. 저자들은 급성 림프구성 백혈병 환자에서 발생한 침습성 국균 심내막염을 2예을 경험하였다. 19세 남자환자로 동종 조혈모세포이식 후 발생한 고열과 요통의 원인으로 감염성 심내막염 진단하에 수술결과 국균에 의한 감염으로 확증되어 수술적 절제술과 liposomal amphotericin B로 치료하였으나 국균 심내막염의 재발과 국균 척추염의 악화, 뇌 출혈로 사망하였다. 23세 남자환자로 관해요법 후 발생한 고열과 요통의 원인으로 국균 심내막염과 국균 척추염 진단하에 수술적 절제술과 amphotericin B로 치료하여 1년 2개월 동안 국균 심내막염의 재발은 없었으나 지속적인 백혈병의 재발과 국균 척추염의 악화, 침습성 폐 국균증으로 사망하였다. Although Aspergillus endocarditis has rarely been reported, it can cause fatal complications in hematologic malignancy patients and allogeneic stem cell transplant recipients. We experienced two cases of aspergillus endocarditis developed in acute lymphoblastic leukemia patients. Case; A 19-year-old patient developed Aspergillus endocarditis after allogenic hemopoietic stem cell transplantation. He was treated with surgical intervention and liposomal amphotericin B. He died of recurred Aspergillus endocarditis and cerebral hemorrhage probably related with aspergillosis of central nervous system. Case 2; A 23-year-old patient developed invasive Aspergillus endocarditis after induction chemotherapy. Aspergillus endocarditis was successfully treated by surgical intervention and amphotericin B. He died of refractory neutropenic fever and sepsis after the third relapse of leukemia and repetitive chemotherapy. He probably had invasive pulmonary aspergillosis without evidence of endocarditis recurrence. Because the mortality of Aspergillus endocarditis is very high, early diagnosis and surgical intervention are very important for better outcome.

IEEE 802.11a 기저대역 프로세서의 설계 및 구현

김상인,최원철,이제훈,조경록 충북대학교 컴퓨터정보통신 연구소 2006 컴퓨터정보통신연구 Vol.14 No.2

본 논문에서는 IEEE 802.11a 표준안에 적합한 기저대역 프로세서를 설계하였다. 프로세서의 크기 감소 및 성능 향상을 위해 새로운 알고리즘이 적용되었다. 구현된 IEEE 802.11a baseband processor는 기존의 OFDM 방식 모뎀의 성능향상을 위해 고속의 IFFT/FFT를 이용하고, 다중경로 채널과 페이딩에 강한 새로운 채널 보상기법과 등화기, tan^(-l) 기법을 이용한 동기회로 그리고 에러 예측 회로를 사용한 비터비 디코더등 개선된 알고리즘을 이용하여 성능향상을 도모하였다 설계된 기저대역 프로세서의 구현 및 검증을 위해 SoC플랫폼을 이용하였다. 플랫폼 기반의 IEEE 802.11a WLAN을 설계하기 위한 환경은 기저대역 프로세서 칩을 테스트하기 위한 테스트 보드와 MAC을 이행할 SoC 플랫폼으로 구성되어 있다. 설계된 IEEE 802.11a baseband processor는 AWGN, 다중 경로 페이딩 채널에서 데이터 전송을 확인하였다.

Dissolved Air Flotation(DAF) 접촉조의 수리동력학적 조건이 입자의 제거에 미치는 영향

유제선,김성훈,신은허,박희경 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

Hydrodynamic conditions for optimum solids capture within the contact zone, which are governed by the geometry and flow, are not yet well understood. In this research, dimensionless parameters which represent hydrodynamic conditions in the contact zone were derived, using the Buckingham π theorem. Those parameters are Reynolds No. (Re), Froude No. (Fr), Weber No. (We), Local Weber No., and Bubble Capacity No. (Bc). The particle removal rate was investigated by changing each value of the dimensionless parameters. The experimental results indicate that particle removal rate, when gravity dominates and the flow is semi-turbulent (Fr < 0.3, Re < 8000), is higher than when inertia dominates and flow is turbulent. For the We, higher removal rates were obtained in the range of the We < 40. Relative to the Local We, smaller bubbles which are influenced more by surface tension than inertia, demonstrated a higher particle removal rate than larger bubbles. For the Bc, the optimal range is from 0.3 to 0.5. We suggest that these dimensionless parameters can be used to diagnose the performance of and to design a DAF reactor.

한국인의 우울증 진단기준의 특성

장성만,손지훈,이준영,최지환,조성진,전홍진,함봉진,이동현,조맹제 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.5

목적 국내의 여러 역학 조사에 따르면 한국인은 서구에 비하여 우울증의 유병률이 낮은 것으로 보고되고 있다. 낮은 유병률에 대하여 서구에서 정의하는 우울증의 진단 기준이 한국인의 문화에 맞지 않다는 진단 기준의 오류를 제시하거나, 실제로 유병률이 낮다는 설명을 시도하기도 하였다. 본 연구는 DSM-IV에서 제시하는 우울증의 진단 기준에 대하여 한국인의 반응 특성을 알아보고자 한다. 방법 2001년 KECA 연구에 응답한 만 18세 이상 65세 미만의 6,275명을 대상으로 하였다. 한국어판 CIDI (K-CIDI)를 통해 정신장애의 이환을 진단하였으며, K-CIDI 내의 우울장애 진단 기준만을 추출하여 분석하였다. 분석은 문항반응이론(Item Response Theory)을 적용하였다. 결과 한국인에서 DSM-IV의 주요우울장애 진단 기준의 오류는 없었으나, 진단 기준의 역치는 높았다. 한국인이 호소하는 우울증상으로서 "피로감"과 "집중력 저하", "수면 변화"는 진단되는 우울증의 초기부터 잘 나타나는 증상 들이며, "정선운동변화", "죽음/자살사고", "무가치함/죄책감"은 보다 심한 우울증에서 잘 나타나는 증상들이었다. 결론 DSM-IV가 제시하는 주요우울장애 진단 기준은 한국인의 우울증을 평가하는 데 있어 타당하기는 하나, 진단 기준의 역치가 높다. 우울증의 중증도에 따라 호소하는 증상들이 달랐다. Baekgrounds : Many Korean epidemiologic studies reported lower prevalence rates of depression than those of Western countries. For the low prevalence, it is explained that there's something wrong in the direct application of diagnostic criteria of depression to Korean culture, i.e. categorical fallacy, or it may be truly low-prevalent. We will analyze diagnostic criteria for depression detined by Western. Methods : Six thousand and two hundred seventy-five cummunity dwelling subjects, aged 18-64 years were interviewed by using Korean version of Composite International Diagnostic Interview (K-CIDI). Diagnostic criteria for depression defined by DSM-IV were analyzed using the item response theory. Rcsults : We could not find any fallacies of diagnostic critcria tbr depression defined by DSM-IV when assessing depre-ssion among Koreans. Fatigue, concentration difficultics, and sleep disturbance appeared more fequently in mild depression, while psychomotor change, death/suicide, and worthlessness/guilt did not appear until severe depression. Cunclusion : The diagnostic criteria for depression defined by DSM-IV arc appropriate for the Koreans. There are different responding levels, i.e. threshold, of depressive criteria according to severities of depression. Koreans with depression are more likely to complain of appetite change, but less of worthless or guilty feelings than Western people.

운동전략이 기립자세의 기능적 전방 팔뻗기에 미치는 영향

박제상,권오윤,최흥식,김택훈 한국전문물리치료학회 2000 한국전문물리치료학회지 Vol.7 No.1

The purpose of this study is to determine whether movement strategies affect functional forward reach distance in a standing position. Forty-seven healthy subjects were selected for this study: 23 men and 24 women, with an average age of 22.3. Functional forward reach distances were measured as hip strategy and squat strategy(included knee and ankle movement strategy) in a standing position, respectively. The mean values of functional forward reach distance in hip strategy, squat strategy were 33.57㎝, 29.48㎝, respectively. There was significantly difference in functional forward reach distance between hip strategy and squat strategy(p<.001). There was no difference of functional forward reach distance between male and female in hip strategy, but there was significant difference in other strategy(p<.05). These results suggest that movement strategies should be considered during functional forward reach test in standing. Further study is required to determine whether movement strategies affect functional reach distance in elderly and disabled groups.

남자 알코올 의존 환자의 기질적 특성에 관한 연구

김성곤,민영기,이덕기,김미영,송영상,권도훈,고영훈,박제민,정병선 대한생물치료정신의학회 2003 생물치료정신의학 Vol.9 No.1

목 적: 본 연구의 목적은 한국인 남자 알코올 의존 환자의 기질적 특성을 Temperament and Character Inventory(TCI)를 이용하여 조사하는 것이다. 방 법: DSM-Ⅳ 진단 기준에 맞는 알코올 의존 환자 30명과 정상인 36명을 대상으로 연구학적 특성을 조사하고, 기질적 특성을 한글판 TCI를 이용하여 조사하였다. 모든 대상자의 나이는 30~60세였다. 결 과: 1) 두 군간 평균 나이는 유의한 차이가 없었으나, 교육 정도와 결혼을 유지하고 있는 비율 및 취업률은 알코올 의존군이 정상 대조군에 비해 유의하게 낮았다. 2) 알코올 의존군에서는 정상 대조군에 비해 Harm Avoidance(HA) 점수와 Self-transcendence(ST)점수는 유의하게 높았으며, Self-directiveness(SD)점수는 유의하게 낮았다. 3) 알코올 의존군 내에서의 각 척도들 간의 상관관계는, HA와 SD 점수, HA와 Persistence(PE) 점수, ST와 SD 점수는 각각 유의한 음의 상관관계, ST와 PE 점수, SD 점수와 Cooperativeness(CO) 점수, Reward Dependence(RD)와 CO 점수는 양의 상관관계를 보였다. 결 론: 이러한 본 연구의 결과는 한국인 남성에서 수줍음을 잘 타며, 걱정도 많고, 염세적이고 쉽게 피로해지는 기질적 특성이 알코올 의존과 연관성이 있음을 의미한다. Objectives : The purpose of this study was to assess the temperament of male parients with alcohol dependence. Methods : The subjects were 30 patients who met DSM-Ⅳ criteria for alcohol dependence and 36 normal controls. All subjects completed Temperament and Character Inventory(TCI) which was developed by Cloninger. Results : 1) The educational level, marital status, and occupation in alcohol dependence group were significantly lower than those of normal control group, but there was no difference in the age between two groups. 2) Among the scores of TCI, the score of harm avoidance(HA) and self-transcendence(ST) were significantly higher in the alcohol dependence group than in the normal control group. 3) In the alcohol dependence group, a significant negative correlation among the scores of TCI was between HA and SD, HA and Persistence(PE), ST and SD, and positive correlation between ST and PE, SD and Cooperativeness(CO), Reward Dependence(RD) and CO. Conclusion : These results suggest that shy, fearful, pessimistic and fatigable temperament are related to developing alcohol dependence in Korean males.

정상 성인에서 갈근(Radix puerariae)의 장기투여가 혈중 알콜 농도에 미치는 영향

박제민,김지훈,김명정,김성곤,정영인 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.6

알콜 의존에서 알콜 소비량을 감소시키고 음주 재발을 방지하는데 효과가 있다는 약물들이 몇 가지 있으며 갈근이 알콜 의존증의 치료에 효과가 있다는 자료들이 있다. 저자들은 정상 성인을 대상으로 알콜을 섭취하게 한 후 갈근 투여 전, 후의 혈중 알콜 농도를 비교함으로써 갈근이 알콜 대사를 방해하여 혈중 알콜 농도를 상승시키는지를 검증하고자 하였다. 알콜을 비롯한 약물 남용이나 의존증이 있거나 기타 정신 질환이 없고 주요 신체질환이 없는 20∼29세 남자 의과 대학생들을 대상으로 하였다. 대상자는 모두 25% 알콜을 3ml/kg(100%알콜 0.75ml/kg)을 마시게 한 후 투여 전, 투여 후 10, 30, 60, 90, 그리고 120분에 혈중 알콜 농도를 측정하게 한 다음 14일간 갈근 하루 6g을 투여한 후 첫날과 같은 방법으로 알콜을 복용하게 한 후 알콜 혈중 농도를 측정하여 약물 투여 전, 후의 알콜 혈중 농도를 비교한 결과 갈근 투여 후에 음주시 30, 60, 90, 그리고 120분에 혈중 알콜 농도가 유의하게 상승하였다. In alcohol dependence, some drugs reduce alcohol consumption and prevent the recurrence of alcohol drinking. There were some evidences that Radix puerariae was effective in the treatment of alcohol dependence. We studied the effect of Radix puerariae on blood alcohol concentration in healthy adults. The subjects were medical students, who did not have major physical disorders, drug abuse or dependence including alcohol, and other psychiatric disorders. After drinking 25% alcohol 3ml/kg, all subjects were measured for blood alcohol concentration at 0, 10, 20, 30, 45, 60, 120 minutes by Alco-sensor Ⅳ. Next day, all subjects were made to take Radix puerariae 6g/day(3g bid) for 14 days. And then blood alcohol concentration were measured by the same method. The results were significant increase in blood alcohol concentration at 30, 60, 90 and 120 minutes.