2개의 내측 유관나사를 이용한 관절경하에서의 족근 관절 고정술

김학준,김택선,윤정로,김경수,노행기,윤광섭,Kim, Hak-Jun,Kim, Taik-Seon,Yoon, Jeong-Ro,Kim, Kyoung-Soo,Noh, Haeng-Kee,Yoon, Kwang-Sup 대한족부족관절학회 2004 대한족부족관절학회지 Vol.8 No.2

Purpose: We evaluated the clinical and radiological results of arthroscopic ankle fusion using 2 medial screws which had advantages of less morbidity, early weight-bearing and high union rate. Material and Methods: From April, 2002 to March, 2004, 8 patients who had ankle osteoarthritis were treated by ankle fusion using 2 medial screws under arthroscopy; five patients with post-traumatic osteoarthritis, two with post-infectious arthritis and one with paralytic foot. There were 5 male and 3 female. Average age was 67 years old ranging from 57 to 71 years. We evaluated them clinically preoperative and postoperative using AOFAS score, VAS pain scale and patient's satisfaction. In regard to radiological fusion, we checked them by simple AP, lateral and mortise view. Follow up period was average 11 months (range, $6{\sim}24$ months). Results: All ankles were successfully fused with 2 medial screws under arthroscopy. The mean time of fusion was 10.5 weeks (range, $8{\sim}14$ weeks). Patient's satisfaction checked at 6 months after operation had favorable results (excellent and good 75%). One case had pain on medial malleolar area because of screw's protrusion. Conclusion: Arthroscopic ankle fusion using 2 medial screws was good modality of ankle fusion with less morbidity and early weight-bearing in some cases of ankle arthritis.

자동차 에어컨 컴퓨터 시뮬레이션

김학준,정동수,김종보,김기효,강정길,Kim, H.J.,Jung, D.S.,Kim, C.B.,Kim, K.H.,Kang, J.K. 대한설비공학회 1996 설비공학 논문집 Vol.8 No.2

The refrigeration cycle of automobile air-conditioners is simulated in an effort to provide a computational tool for optimum thermodynamic design. In the simulation, thermodynamic and heat transfer analysis was performed for the four major components : evaporator, condenser, compressor, and expansion valve. Effectiveness-NTU method was used for modeling both evaporator and condenser. The evaporator was divied into many subgrids and simultaneous cooling and dehumidifying analysis was performed for each grid to predict the performance accurately. Blance equations were used to model the compressor instead of using the compressor map. The performance of each component was checked against the measured data with CFC-12. Then, all the components were combined to yield the total system performance. Predicted cycle points were compared against the measured data with HFC-134a and the deviation was found to be less than 5% for all data. Finally, the system model was used to predict the performance of CFC-12 and HFC-134a for comparison. The results were very reasonable as compared to the trend deduced from the measured data.

나의 해외유학 및 연구생활 회상기(1)

김학준,Kim, Hak-Jun 대한출판문화협회 1989 출판저널 Vol.47 No.-

경제성 분석에 의한 싱글쉘 터널의 국내 적용성 검토 연구

김학준,신휴성,Kim, Hak-Joon,Shin, Hyu-Seong 한국터널지하공간학회 2008 한국터널지하공간학회논문집 Vol.10 No.2

터널공사비에 대한 국내외의 사례 조사 결과 싱글쉘 터널은 기존의 콘크리트 라이닝을 설치하는 이중쉘 터널에 비하여 공사비가 저렴하였다. 그러나 암반 상태가 불량해 질수록 싱글쉘 터널의 경제성은 급격히 저하되었다. 따라서 싱글쉘 공법은 암반상태가 양호한 지반에 적용해야 한다. 국내의 경우 일반적으로 여러 암반 등급이 다양하게 나타나므로 양호한 암반과 불량한 암반의 비율을 고려하여 싱글쉘 공법의 적용 여부를 판단해야 한다. 싱글쉘에 이용되는 숏크리트 및 록볼트는 영구지보재로서 고품질이어야 하므로 지보재료의 저렴한 공급여부에 따라서 싱글쉘 공법의 적용 대상 암반이 확대될 수 있을 것으로 기대된다. The construction cost for the single shell tunnel is cheaper than that of the double shell tunnel according to the case studies performed in several domestic and foreign tunnels. However, the economic advantage of single shell tunnel drops drastically as the condition of the rock mass deteriorates. Therefore, the single shell tunnelling method should be applied to the good rock mass conditions. The application of the single shell tunnelling method to tunnels in Korea should be determined considering the ratio between the good rock and poor rock masses along the tunnel section. The use of the single shell tunnel is expected to offend depending on the cheap supply of high quality shotcrets and rock bolts developed for single shell tunnels.

The Effect of Platelet Rich Plasma from Bone Marrow Aspirate with Added Bone Morphogenetic Protein-2 on the Achilles Tendon-Bone Junction in Rabbits

김학준,Hyok-Woo Nam,허창룡,Misu Park,Hee Seok Yang,Byung-Soo Kim,박정호 대한정형외과학회 2011 Clinics in Orthopedic Surgery Vol.3 No.4

Background: To determine if exogenously injected bone marrow derived platelet-rich plasma (PRP) plus bone morphogeneticprotein (BMP)-2 could accelerate the healing of bone-tendon junction injuries and increase the junction holding strength during theearly regeneration period. Methods: A direct injury model of the bone-tendon junction was made using an Achilles tendon-calcaneus bone junction in a rabbit. In the PRP/BMP-2/fi brin group, 0.05 mL of bone marrow derived PRP and 100 ng/mL of BMP-2 both incorporated into 0.1 mLof fi brin glue were injected into Achilles tendon-calcaneus bone junctions. The effect of the intervention was tested by comparingthe results of an intervention group to a control group. The results of biomechanical testing, and histological and gross analyseswere compared between the 2 groups at the following time points after surgery: 2 weeks, 4 weeks, and 8 weeks. Results: Histologic examinations showed that woven bone developed in tendon-bone junctions at 2 weeks after surgery in thePRP/BMP-2/fibrin group. Mechanical test results showed no significant difference between the PRP/BMP-2/fibrin and controlgroups at 2 and 4 weeks after surgery, but the mean maximal load in the PRP/BMP-2/fi brin group was signifi cantly higher than inthe control group (p < 0.05) at 8 weeks after surgery. Conclusions: Bone marrow derived PRP and BMP-2 in fi brin glue accelerated healing in a rabbit model of tendon-bone junctioninjury.

개량형 격자지보재의 성능 평가

김학준,배규진,김동규,Kim, Hak-Joon,Bae, Gyu-Jin,Kim, Dong-Gyu 한국터널지하공간학회 2013 한국터널지하공간학회논문집 Vol.15 No.3

격자지보재는 기존의 H형강 지보재를 대체하여 현재 국내의 터널현장에서 널리 사용되고 있다. 그러나 격자지보재는 H형강 지보재에 비하여 강성이 떨어지며 이음부를 연결하는 용접에 만전을 기해야 한다는 단점이 있다. 이러한 문제를 개선하기 위하여 연결용 부재가 추가되고 용접부위를 편평하게 만든 개량형 격자지보재가 국내 기술에 의하여 개발되었다. 본 연구에서는 기존 격자지보와 개량형 격자지보에 대한 실내시험 및 현장계측을 수행하여 개량형 격자지보의 성능을 평가하였다. 실내 압축시험결과에 의하면 개량형 격자지보가 기존 격자지보에 비하여 약 16% 정도 큰 지지하중을 보였다. 현장 계측 결과에 의하면 개량형 격자지보가 기존 격자지보보다 강봉의 휨이 적게 발생하여 터널의 안정성 측면에서 더 우수하였다. Lattice girders are widely used as a substitute for H-steel ribs at domestic tunnels. However, lattice girders have a weak point in terms of the support capacity compare to H-steel ribs because of the lower stiffness and the weakness of the welded parts. To improve the weakness of the lattice girder, reformed lattice girders are developed in Korea by adding one more spider and having flat welded surface. Laboratory tests and field measurements were performed for the original and the reformed lattice girders to evaluate the performance of the reformed lattice girders. According to the laboratory compression test, reformed lattice girders have 16% higher load bearing capacity than that of original lattice girders. Reformed lattice girders are more stable than original lattice girders because reformed lattice girders tend to bend less according to the field measurements.

고효율 수퍼히트펌프에 관한 전산 해석

김학준,정동수,김종보,하경용,Kim, H.J.,Jung, D.S.,Kim, C.B.,Ha, K.Y. 대한설비공학회 1995 설비공학 논문집 Vol.7 No.2

A super-heat pump system composed of a suction line heat exchanger, low and high stage economizers, and a screw compressor is simulated to examine the energy performance and design options. CFC12, HCFC22, HFC134a, HCFC22/HCFC142b, HFC32/HFC134a, and HFC125/HFC134a are used as working fluids for comparison. The results indicate that the proposed system charged with appropriate mixtures is up to 33.4% more energy efficient than the normal system with CFC12. The performance of the super-heat pump system charged with mixtures was influenced by such factors as the temperature matching, heat source temperature difference, low stage economizer, and high stage economizer. The fluids with a larger liquid specific heat such as HFC134a would have more benefits when a suction line heat exchanger is installed. 40%HCFC22/60%HCFC142b mixture seems to be a good candidate to replace CFC12. On the other hand, 25%HFC32/75% HFC134a would be a good long term candidate to replace HCFC22.

베트남전 참전자 2세의 건강상태에 관한 조사 - 부산지역 고엽제 위해증 환자를 대상으로 한 설문조사 결과 -

김학준,손혜숙,엄상화,박수경,유병철,이종태,전진호,Kim, Hak-Joon,Sohn, Hae-Sook,Urm, Sang-Hwa,Park, Soo-Kyung,Yu, Byung-Chul,Lee, Jong-Tae,Chun, Jin-Ho 대한예방의학회 2000 Journal of Preventive Medicine and Public Health Vol.33 No.1

Objectives : To propose the referential data to evaluate the health impacts of Vietnam veterans' children whose father were exposed to herbicides in Vietnam War. Methods : Vietnam veterans who visited to Pusan Veteran Hospital for medical care were recruited from April to October, 1998. They were 71 and asked about their own combat history, symptoms and illness, and health status of their 182 children. The informations were collected by direct and phone interview. Exposure estimation was also performed as exposure score depending on year and unit of participation, and personal episodes related to exposure to herbicide in the war. It classified into three groups; lower(<18.0), moderate(18-53), high$(\geq53)$ exposure group. Results : The mean age and the period into the combat of the veterans were 52.8 years and 15.0 months. The mean exposure score was $18.1{\pm}9.9$, and mainly distributed in lower (46.5%) and moderate(52.1%) exposure group. Most(90.1%) of them were diagnosed as sequelae(21 cases) and suspected sequelae(43 cases) of the herbicides by Korean veteran's hospital diagnostic criteria. The major sequelae was peripheral neuropathy 13 cases, chloracne 5 cases, and the major suspected sequelae was hypertension 20 cases, diabetes mellitus 18 cases, liver disease 12 cases, central neuropathy 11 cases, etc. About birth, 42.2% and 16.9% experienced spontaneous abortion and stillbirth, respectively. The mean exposure score was higher in stillbirth experience group(p<0.05). About half of the children(90 cases, 49.5%) hold the abnormal health status: those were skin pigmentation 38 cases, rash 23 cases, congenital anomaly 15 cases, general weakness 12 cases, purpura 8 cases, visual disturbance 8 cases, etc. These health problems had no association with father's exposure level(p>0.05). Conclusions : These results were depend on their own answers, and expectation for compensation did not excluded, therefore, this study may have limitations: inaccuracy of informations due to recall bias and response bias. Nevertheless, through this study, we could image the fundamental aspect for health impacts of Vietnam veterans' children for preparing the national control program and policy. A large scale epidemiologic study with valid exposure assessment on the health impacts of Vietnam veterans' children is recommneded.

종합서평 - 한국정치의 현실분석과 미래전망

김학준,Kim, Hak-Jun 대한출판문화협회 1990 출판저널 Vol.55 No.-

나의 학문편력

김학준,Kim, Hak-Jun 대한출판문화협회 1989 출판저널 Vol.48 No.-