원전기기 부품의 수명추정 및 활성화 에너지측정

김재형,김유창,김병덕,Kim, Jae-Hyeong,Kim, Yu-Chang,Kim, Byeong-Deok 재료연구소 2001 機械와 材料 Vol.13 No.4

${\bigcirc}{\bigcirc}$터널 붕락부와 붕락이후구간 시공사례

김재형,박홍진,조주호,최병희,이기성,Kim, Jae-Hyeong,Park, Hong-Jin,Jo, Ju-Ho,Choe, Byeong-Hui,Lee, Gi-Seong 한국지반공학회 2012 지반 : 한국지반공학회지 Vol.28 No.10

감염성 안구내염의 초음파 소견

김재형,최재완,윤영희,김중곤.Jae-Hyung Kim. M.D.. Jae-Wan Choi. M.D.. Young-Hee Yoon. M.D.. June-Gone Kim. M.D. 대한안과학회 2005 대한안과학회지 Vol.46 No.4

Purpose: To investigate the correlation between ultrasonographic findings and clinical features of infectious endophthalmitis. Methods: We analyzed ultrasonographic findings of 38 eyes of 36 patients who had been diagnosed as having infectious endophthalmitis with various etiologies. The correlation between ultrasonographic findings and clinical features such as initial and final visual acuities were studied. Results: Fourteen eyes were diagnosed with endogenous endophthalmitis and 11 eyes with postoperative endophthalmitis. Posterior vitreous opacity in the endophthalmitis secondary to keratitis was more severe and subhyaloid opacity in the traumatic endophthalmitis was less severe. Coagulase negative staphylococcus was the most common causative agents. Subhyaloid opacity in the eyes where cultures were not performed, was more severe than in those where coagulase negative staphylococcus was identified. Among the various ultrasonographic findings only the degree of the posterior vitreous opacity was correlated with the initial visual acuity, and none of the findings was significantly related with the final visual acuity. Treatment modalities included intravitreal antibiotics injections in 13 eyes, immediate vitrectomies and antibiotics injection in 6 eyes, conversion to vitrectomy after antibiotics injection in 17 eyes, and eviscerations in 2 eyes. The grades of posterior vitreous opacity of the patients with conversion to vitrectomy after antibiotics injection were lower than those of the other groups. Conclusions: Ultrasonographic findings might be a useful factors in the diagnosis and the determination of treatment modality and may therefore be helpful in the prognosis of patients with suspected infectious endophthalmitis.

저수지 유입량 예측을 위한 신경망 모형의 특성 연구

김재형,윤용남,Kim, Jae-Hvung,Yoon, Yong-Nam 한국방재학회 2002 한국방재학회논문집 Vol.2 No.4

In this study the results of Chungju reservoir inflow forecasting using 3 layered neural network model were analyzed in order to investigate the characteristics of neural network model for reservoir inflow forecasting. The proper neuron numbers of input and hidden layer were proposed after examining the variations of forecasted values according to neuron number and training epoch changes, and the probability of underestimation was judged by deliberating the variation characteristics of forecasting according to the differences between training and forecasting peak inflow magnitudes. In addition, necessary minimum training data size for precise forecasting was proposed. As a result, We confirmed the probability that excessive neuron number and training epoch cause over-fitting and judged that applying $8{\sim}10$ neurons, $1500{\sim}3000$ training epochs might be suitable in the case of Chungju reservoir inflow forecasting. When the peak inflow of training data set was larger than the forecasted one, it was confirmed that the forecasted values could be underestimated. And when the comparative short period training data was applied to neural networks, relatively inaccurate forecasting outputs were resulted and applying more than 600 training data was recommended for more precise forecasting in Chungju reservoir. 본 연구에서는 3층 신경망 모형에 의해 충주호의 유입량을 예측한 결과들을 이용하여 신경망 모형의 저수지 유입량 예측 특성을 분석하였다. 신경망 모형의 적절한 입력층 및 은닉층 뉴런 개수, 학습회수를 제시하였으며, 학습 첨두유량 크기가 예측된 첨두유량보다 작을 경우 예측 값이 과소평가되는 특징을 확인하였다. 또한 뉴런 개수, 학습회수가 과다할 경우 발생 가능한 과적합 현상을 확인하였으며, 정확한 예측을 위해 필요한 최소 학습자료 기간도 제시하였다. 결과적으로 충주호의 경우 $8{\sim}10$개의 뉴런 개수 및 $1500{\sim}3000$회의 학습회수를 이용한 신경망 모형이 적합한 것으로, 학습자료 기간 수는 최소한 600개 이상의 자료를 적용하여야 정확한 예측이 가능한 것으로 결과되었다.

The Effects of Alendronate on Healing of the Calvarial Defect in Rats

김재형,이재목,박진우,서조영,Kim, Jae-Hyung,Lee, Jae-Mok,Park, Jin-Woo,Suh, Jo-Young The Korean Academy of Periodontoloy 2004 Journal of Periodontal & Implant Science Vol.34 No.4

Bisphosphonates는 파골세포에 의한 골흡수를 방지하는 물질로 알려져 있으며 임상에서 널리 쓰이고 있다. 그 중 Alendronate는 Aminobisphosphonates의 한 종류로 non-aminobisphosphonates인 etidronate보다 100-1000배 더 강한 효과를 보이는 것으로 알려져 있다. 본 실험의 목적은 백서두개골 결손부의 골재생을 실험모델로 하여 alendronate의 국소투여 효과를 알아보는 것으로 액체의 흡수성과 골전도성이 우수한 것으로 알려진 collagen membrane을 사용하여 결손부 양측에 alendronate와 physiologic saline을 각각 적용하여 1주, 2주, 4주의 조직학적 치유양상, 파골세포활성도, 경도를 평가하였다. 조직학적 치유양상은 1주째 collagen membrane에 의한 염증성 침윤이 나타났으며 2주째부터 골성회복이 관찰되었고 4주째 완전한 골성회복을 보여 각주별 실험군, 대조군 공히 유사한 양상을 보였고 실험에 사용한 $200{\mu}g$의 용량은 조직학적으로 관찰할만한 골재생의 향상을 위해서는 부족한 용량으로 사료되는 바이다. TRAP(+) cell은 1주째 대조군에 비해 실험군에서 유의하게 적은 수를 보였으며(p<0.01) 2주와 4주째는 유의한 차이를 나타내지 않았고 경도측정에서는 2주째 대조군에 비해 실험군에서 유의하게 높은 경도를 보였으며 4주째 유의한 차이를 나타내지 않았다(p<0.05). 이상의 실험에서 alendronate는 골조직 치유과정의 초기에 파골세포의 활성도와 경도에 다소 영향을 미친 것으로 사료되며 향후 골조직 재생을 위한 임상적용에 응용을 위해서는 치유과정을 더욱 향상시킬 수 있는 추가적인 연구가 필요하리라 사료된다. The present study aimed to examine the effects of topical application of alendronate with a collagen membrane on the healing of the calvarial defect in rats, which has a good experimental design for the healing of tissue destruction, To study the effect of alendronate on bone healing, the collagen membrane containing $200{\mu}g$ alendronate was inserted in the defects of the right side and collagen membrane treated with physiologic saline was inserted in the defects of the left side. After 1, 2 and 4 weeks, observation of histologic feature after H&E staining, cell counting after TRAP staining, and hardness measurement(Knoop) were performed. In histologic finding, similar features were shown for both test and control groups each week. In cell counting only the 1 week test groups showed significant reduction of TRAP(+)cells than control groups(p<0.01) and the control groups showed statistically significant difference for 1, 2, 4weeks(p<0.05). In hardness measurement, The 2 week test groups showed significant higher hardness than control groups.(p<0,05) and not 4 weeks. There was significant increase of hardness for both groups as time goes by.(p<0.0l) Therefore local application of alendronate with collagen membrane was somewhat effective in reducing osteoclastic activity and increasing hardness in the early stage of healing. Further investigation concerning the actual effect of alendronate for bony healing will be necessary to apply the clinical cases

기술현황분석 - 미세 입자의 고효율 건조를 위한 분무동결건조 기술

김재형,류경하,Kim, Jae-Hyeong,Ryu, Gyeong-Ha 재료연구소 2013 機械와 材料 Vol.25 No.3

최근 식품, 정밀화학, 바이오와 같은 다양한 산업분야에서 건조 기술에 대한 관심이 늘고 있다. 이에 다양한 피건조물의 건조를 위하여 다양한 건조기술이 사용되고 있으며, 그 중에서 동결건조 기술은 물리적/화학적 안전성, 생화학적 보존성 및 복원성 등의 특성을 갖기 때문에 각광받고 있다. 이러한 동결건조 기술을 기반으로 미세 입자 형태의 분말 제조를 가능하게 하기 위하여, 한국기계연구원에서는 고효율의 분무동결건조를 위한 장치의 개발을 진행하고 있다.

일본의 최근 다이옥신류 Monitoring 결과와 대책

김재형,Kim, Jae-Hyeong 환경보전협회 1999 환경정보 Vol.21 No.9

경부에 발생한 지방모세포종 1예

김재형,최인학,김영찬,백승국,Kim, Jae Hyung,Choi, ln Hak,Kim, Young-Chan,Baek, Seung-Kuk 대한두경부종양학회 2019 대한두경부 종양학회지 Vol.35 No.1

Lipoblastoma is a rare benign tumor with 80-90% occurring in children less than 3 years of age and 40% occurring in children less than 1 year of age. The most common site of incidence is limb, and then trunk. Neck is the rare site of incidence. The main symptom that the patient complains about is a rapidly growing neck mass without pain. When the size of mass increases, it can cause dyspnea, Horner's syndrome. Lipoblastoma is usually diagnosed as a lipoma in the fine needle aspiration. Since it is not differentiated from lipoma, liposarcoma, and hibernating adenoma in CT and MRI, the definitive diagnosis is histologic diagnosis through surgical resection. The treatment is complete surgical resection. And recurrence rate is 9-25% due to incomplete resection. Authors report this case with a review of literatures since we experienced a case of lipoblastoma diagnosed histopathologically after surgical treatment of neck mass.

촉매 및 반응공학 Poster 발표 : 조촉매 Ni 과 CO 가 담지된 Tungsten nitride 촉매의 특성화 및 HDN 활성에 관한 연구

김재형,이진구,김경림 (정) ( Jae Hyung Kim,Jihn Koo Lee,Kyung Lim Kim ) 한국화학공학회 1994 춘계학술발표회 Vol.- No.-

인공시계기반 헬기용 3차원 항법시스템 구성

김재형,유준,곽휘권,Kim, Jae-Hyung,Lyou, Joon,Kwak, Hwy-Kuen 한국군사과학기술학회 2008 한국군사과학기술학회지 Vol.11 No.3

An artificial vision aided NDGPS/INS system has been developed and tested in the dynamic environment of ground and flight vehicles to evaluate the overall system performance. The results show the significant advantages in position accuracy and situation awareness. Accuracy meets the CAT-I precision approach and landing using NDGPS/INS integration. Also we confirm the proposed system is effective enough to improve flight safety by using artificial vision. The system design, software algorithm, and flight test results are presented in details.