요추간반의 위치 결정에 관한 연구

김정식,석종식,한대희,심보성 대한신경외과학회 1976 Journal of Korean neurosurgical society Vol.5 No.2

Although transitional vertebrae are relatively frequent in lumbosacral area, it is generally accepted that one cannot state whether the transition is due to lumbarization of S₁ or sacralization of L_(5) from simple lumbar X-ray film alone. However, 'for the practical purpose, the anther attempted to obtain a possible method to determine the level of the lumbosacral spine in simple X-ray films through the analysis of the 100 operated patients and 250 lumbago and/or sciatca patients. Furthermore to determine the level of the inter-vertebral disc space in post-operative films, a silver clip was attached near the operated region and reviewed the post-operative findings in simple lumbar X-ray films. The resutls were as follows: 1) To determine the level of the intervebral disc space in simple lumber X-ray films, origin of the psoas muscle shadow can be utilized as a landmark with about 80% accuracy. But if one leave the silver clip at the operated region, he can state the level in 100% accuracy with the information of pre-operative symptoms. 2) Sacralization was 10% n operated cases, 6% in non-operated cases and lumbarization was 6% in operated cases, 3.2% in non-operated cases. Spina bifida was 12% in operated cases, 11.2% n non-operated cases. Lumbar rib was 2% in all of operated and non-operated cases. Lumbar rib was 2% in all of operated and non-operated cases.

퍼지-슬라이딩모드를 이용한 로봇의 강건추적제어

김정식,최승복 대한기계학회 1994 대한기계학회논문집 Vol.18 No.8

Considerable attention has been given to controller designs that utilize the variable structure system theory in order to achieve robust tracking performance of robotic manipulators subjected to parameter variations and extraneous disturbances. However, the theory has not had wide spread acceptance in practical control engineering community due mainly to the worry of chattering which is inherently ever-existing in the variable structure system. This paper presents a novel type of fuzzy-sliding mode controller to alleviate the chattering problem. A sliding mode controller for robust robot control is firstly synthesized with an assumption that the imposed system uncertainties satisfy matching conditions so that certain deterministic performances can parameters and control rules are obtained from a relation between predetermined sliding surfaces and representative points in the error state space. A two degree-of-freedom robotic manipulator subjected to a variable payload and a torque disturbance is considered in order to demonstrate superior tracking performance accrued from the proposed methodology.

원발성 종격동 정상피종의 전산화단층촬영 소견

김정식 대한영상의학회 1988 대한영상의학회지 Vol.24 No.5

Primary mediastinal seminoma is a rare germ cell tumor that usually occurs in young men. Recently we experienced two cases of primary mediastinal seminoma with CT scan. CT findings were a large anterior mediastinal mass which grows mainly to the left and displaces left brachiocephalic vein posteriorly lobulated tumor margins with small spiculations or projections loss of fat planes between the tumor and surrounding organs and homogeneous density of 40-50 HU in postcontrast study. These CT findings may suggest the possibility of primary mediastinal seminoma before histologic confirmation.

만성미만성 폐질환의 전산화단층촬영 소견

김정식 대한영상의학회 1990 대한영상의학회지 Vol.26 No.2

We evaluated the CT findings of 21 cases of chroinc diffuse lung disease which were diagnosed with open lung biopsy(7), transbronchial lung biopsy(3), bronchoalveolar lavage(4), occupational history(2), skin biopsy(2), liver biopsy(1), bone marrow aspiration(1), clinical functional and radiographic findings(6). CT scans were obtained by using 8mm collimation at 8mm intervals in all patient, and additional high resolution CT scans(1mm collimation) were also obtained in 17 patients of them. Although the traditional classification method of disease distribution into upper, middle and lower zones was somewhat useful, the model of disease distribution proposed by Bergin and Muller was more useful in evaluation of chroinc diffuse lung diseases. The diseases that were mainly distributed in axial compartment were lymphangitic carcinomatosis(5), sarcoitosis(2) and those in middle compartment were silicosis(2), extrinsic allergic alveolitis(1), hypereosinophilic syndrome(1), unclassifie one(1) and in peripheral compartment were fibrosing alveolitis (idiopathic pulmonary fibrosis(3), Rheumatoid lung(1), scleroderma(1), dermatomyositis(1) And in diffuse panbronchiolitis(3), even distribution of lesions to both axial and peripheral compartments was noted. But in fibrosing alveolitis, some degree of distribution was noted in peripheral compartment and in lymphangitic carcinomatosis and silicosis, some degree of distribution was noted in peripheral compartment. Nodular thickening of bronchovascular bundles was characteristically seen in all cases of lymphangitic carcinomatosis and sarcoidosis. The nodules were 1-5mm in diameter and were composes of tumor cells9in lymphangitic carcinomatosis) and of sarcoid granuloma within lymphatics in the bronchovascular sheath. however patients with sarcoidosis did not have irregular thickened interlobular septa and polygojal line. Dilatation of peripheral airways without dilatation of proximal bronchi was only seen in diffuse panbro chiolitis. Although we experienced only two cases of silicosis, the nodules of silicosis were separated from the pleura at a constant distance and seldom touched to the pleura.

신결핵의 전산화 단층촬영 소견

김정식 대한영상의학회 1989 대한영상의학회지 Vol.25 No.4

CT is useful for the evaluation of detailed morphologic change renal function and extrarenal involvement in renal tuberculosis. authors analysed the CT findings of 15 patients of renal tuberculosis which were confirmed at Keimyung University Hospital from Jan '82 to June '88 The results were as follows: 1. The Kidneys were enlarged in 6 cases (40%) and lobulated in 10 cases (67%) 2. The thickness of renal parenchyme was decreased in 13 cases(87%) 3. The renal function was absent in 8 cases (57%) 4. The calyectasis were in 11 cases (73%) and pelvocalyectasis were only in 1 cases(7%) 5. The renal calcifications were in 9 cases (60%) 6. The wall of ureterw were thickened in 11 cases (73%) 7. The extrarenal involvement were in 7 cases (47%) Conclusively we considered the possibility of renal tuberculosis when thickened wall of the renal pelvis and /or ureter calyectasis with renal pelvis contraction and loss of the renal sinus fat were present.

뇌동맥류파열의 전자화단층촬영 및 혈관조영 소견

김정식 대한영상의학회 1984 대한영상의학회지 Vol.20 No.3

CT has become one of the most important diagnostic method in the evaluation of ruptured intracranial aneurysm with direct detection of subarachnoid, intracerebral and intraventricular hemorrhage. and identification of complications such as recurrent bleeding, hydrocephalus and infarction secondary to arterial spasm. Angiography gives precise information on the location, size of aneurysm and presence of arterial spasm. Authors attempted to predict the location of reptured aneurysm in the CT by distribution of blood in subarachnoid spaces and brain parenchyme in comparison with angiographic findings, and also predict the prognosis of the patients by relationship between the extent of blood and clinical grade. Authors analysed 40 cases of ruptured intracranial aneurysm confirmed by CT and angiography at Keimyung Untversity Hospital for last 2 years. The results were as follows: 1. The age and sex distribution ; the most prevalent age group was 5 th to 6th decades (70%), and female patient was slightly more than male patient (57.5%:42.5%). 2. The location of aneurysms were; posterior communicating artery group 17 cases (42.2%), middle cerebral artery group 10 cases (25.0%), anterior communicating artery group 7 cases (17.5%), basilar artery bifucation 1 cases (2.5%), posterior inferior cerebellar artery 1 case (2.5%), and multiple aneurysms 4 cases (10%) in order to frequency. 3. Characteristic distributions of intracranial hemorrhage in CT were as follows; 1) In 6 cases (85.7%) of anterior communicating artery aneurysm, interhemispheric fissure hemorrhage was noted. 2) The ipsilateral sylvian fissure hemorrhage was noted in all cases of middle cerebral artery aneurysm (10 cases) and 12 cases (70.6%) of posterior communicating artery aneurysm. 3) Localized hematoma in frontal lobe near interhemispheric fissure (2 cases : 28.6%), septum pellucidum (1 case:14.3%) and corpus callosum (1 case:14.5%) were characteristic in anterior communicating artery aneurysm. 4) Commashaped sylvian fissure hematoma (5 cases:50%) and temporal lobe hematoma near sylvian fissure (5 cases :50%) may indicate middle cerebral artery aneurysm. 5) Intraventricular hemorrhage (6 cases :15%) has no particular predilection of aneurysmal location. 4. In 9 paients (22.5%) of clinically suggesting subarachnoid hemorrhage, no extravasated blood was noted in preenhancement CT alone. 5. Six cases (15%) showed aneurysm itself on preenhancement CT as a round or ovoid hyperdense area or isodense area with mass effect such as cisternal obliteration. 6. Hydrocephalus was noted in 9 cases (22.5%) 7. there was no direct correlation between the size of the intracranial aneurysm and extent of the hemorrhage in CT, and between the size of the intracranial aneurysm and clinical grade. 8. There was direct correlation between the extent of blood in CT and clinical grade.

한국(韓國) 실질환율(實質換率)의 변동행태(變動行態) 분석(分析) -명목환율제도(名目換率制度)의 중립성(中立性) 논쟁을 중심(中心)으로-

김정식,김진옥 한국국제경제학회 1992 한국국제경제학회 학술대회발표 논문집 Vol.30 No.2

韓國 實質換率의 決定要因 分析

金正湜,金鎭玉 연세대학교 경영연구소 1993 연세경영연구 Vol.30 No.1

티타늄 표면조도가 조골세포의 부착 및 분화에 미치는 영향

김정식,이재관,고성희,엄흥식,장범석,Kim, Jung-Sik,Lee, Jae-Kwan,Ko, Sung-Hee,Um, Heung-Sik,Chang, Beom-Seok 대한치주과학회 2005 Journal of Periodontal & Implant Science Vol.35 No.4

The success of an implant is determined by its integration into the tissue surrounding the biomaterial. Surface roughness is considered to influence the behavior of adherent cells. The aim of this in vitro study was to determine the effect of surface roughness on Saos-2 osteoblast-like cells. Titanium disks blasted with 75 ${/mu}m$ aluminum oxide particles and machined titanium disks were prepared. Saos-2 were plated on the disks at a density of 50,000 cells per well in 48-well dishes. After 1 hour, 1 day, 6 days cell numbers were counted. One day, 6 days after plating, alkaline phosphatase(ALPase) activity was determined. Compared to experimental group, the number of cells was significantly higher on control group. The stimulatory effect of surface roughness on ALPase was more pronounced on the experimental group than on control group. These results demonstrate that surface roughness alters proliferation and differentiation of osteoblasts. The results also suggest that implant surface roughness may play a role in determining phenotypic expression of cells.

Masonry Structure의 고층화에 대한 연구(완)

김정식 대한건축학회 1969 建築 Vol.13 No.1

Masonry Structure의 고층화에 대한 것을 검토하여 보았다. 일본의 법규를 그대로 모방하여 3층이하로 제한할 것이 아니라 강도상 또는 구조상 무리만 없다면 제한을 하지말고 품질관리 또는 기술훈련등을 당국에서 철저히하여 개방하는 것이 현명하지 않을까 사료된다. 시간이 허락하는 대로 앞으로 좀 더 깊이 이 문제에 대하여 연구조사해 보려 한다.