방사선조사에 의한 한국산어류의 품질보존에 관한 연구 : Ⅰ. 민어 , 참조기 및 물가자미의 감마선 조사 후의 보존특성 Ⅰ. Radurization of croaker , yellow corvenia and roundnose flounder

이민철,정종락,김수일 한국수산학회 1976 한국수산과학회지 Vol.9 No.2

민어 (croaker-Nibea imbricata, Matsubara), 참조기 (yellow corvenia-Pseudosciaena manchurica, Jordan and Thompson) 그리고 물가자미(roundnose flounder-Xystrias grigorjewi, Herzenstein) 어육을 0.5 Mrad이하의 감마선량에 조사하여 냉장기간중의 선도 유지기간 연장을 가져오는 최적 조사선량을 구하였다. 조사된 어육을 0˚와 5℃에 35일간 저장하는 동안에 일어나는 관능학적 변화를 미생물학적, 화학적 변화와 비교 검토하였다. 0℃ 저장을 위한 민어와 참조기의 최적선량은 0.1 Mrad였으며 5℃ 저장에서는 0.2 Mrad였다. 물가자미는 방사선 조사에 대단히 민감하여 0˚와 5℃ 다같이 0.1 Mrad였다. 각각의 최적선량에 조사 처리하므로써 민어의 경우 0℃에서는 선도 유지기간이 비 조사구의 2주간에서 5주간(3-4배)으로 연장되었으며 5℃에서는 역시 1주간 이내에서 4주간(4-5배)으로 연장이 가능하였다. 참조기는 0℃에서는 3∼4배로, 5℃에서는 4-5배로 그리고 물가자미는 0℃에서 4-5배, 5℃에서 6-7배로 각각 연장되었다. Optimum doses The optimum dose that may be defined as the dose below the maximum permissible dose, yet would bring about a significant storage life extension at refrigerated temperatures, varied with species of fish as well as with the postirradiation storage temperatures. Thus the dose of 0.1 Mrad was considered to be optimum for the croaker and yellow corvenia at 0℃, while at 5℃ the dose of 0.2 Mrad would be suitable for both species. The roundnose flounder was more radiosensitive and even at the dose of 0.1 Mrad a slight irradiation odor was detected immediately after the radiation treatment. Such degree of irradiation odor disappeared upon stoage, therefore, the dose of 0.1 Mrad was considered to be optimum for the roundnose flounder at both 0˚and 5℃. Storage life extension The croaker meats irradiated at 0.1 Mrad could be held at 0℃ as long as 5 weeks in good acceptable conditions, while the unirradiated control became unacceptable within 2 weeks-3-4 for extension of storage life at 0℃. At the storage temperature of 5℃, the storage life of 0.2 Mrad irradiated samples was extended from less than one week to 4 weeks-4-5 fold extension. The storage life extension of 0.1 Mrad irradiated yellow corvenia at 0℃ was from less than 2 weeks for the unirradiated to 4 weeks-approximately 2-3 folds and that of 0.2 Mrad irradiated samples stored at 5℃ was from 5 days to 3 weeks 4-5 folds. The roundnose flounder meats irradiated at 0.1 Mrad could be held at 0℃ for 3-4 weeks as compared to less than 1 week for the unirradiated and at 5℃ the storage life could be extended from less than 3 days to up to 2 weeks. Thus the storage life extension by 4-5 folds and by 6-7 folds was possible at 0˚and 5℃ storage, respectively. Postirradiation storage microbiology and biochemistry In general 10 fold reduction of initial microflora was realized as a result of irradiating fish samples at 0.1 Mrad. The extent of microflora reduction increased with increasing doses applied, but not proportionately dependent. The microbial growth in the irradiated was severely retarded during the subsequent storage period, lagging far behind that of the unirradiated control samples except in the late storage phase, when the levels of microflora of the irradiated either approached to or rose above the levels of the unirradiated. The microbiological changes caused by irradiation was reflected in the pronounced suppression of TVB and TMA accumulation during the storage period. This suggests that irradiation treatment brought about both quantitative and qualitative changes in microflora initially present and it is reasonable to suggest that the microflora removed by irradiation in fact represent most of the flora capable of producing TVB and TMA in normal fish spoilage process.

디지털 3차원 실물 복제기의 고속 고 정밀 제어

이민철,김정수,유기성,이원희,김동수 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.5월

Network Level 관리를 위한 신규 마찰력 지수 개발 연구

이민철,손덕수,이재훈,김인태 한국도로학회 2015 한국도로학회 학술발표회 논문집 Vol.2015 No.3

포장관리 효율화 방안(2011)에서 고속도로 이용자 설문결과 도로서비스 분야에서 가장 중요도가 높은 항목은 노면상태로 나타났다. 또한 현 도로포장의 문제점으로 주행쾌적성, 미끄럼. 소음 등 정성적 부분 과 안전성이 대부분(82%)을 차지했다. 현재 도로포장의 노면특성을 측정하는 방법은 1개 차로에서 2개 지점을 정하여 측정해 차로의 대푯값으로 사용한다. 그러나 실제 운전자 습관에 따라 측정 지점만 운행하 지 않고 다양하게 주행 패턴이 나타난다. 운전자의 습관이나 주행패턴이 다양하기 때문에 지점 측정을 통한 관리가 아닌 Network Level의 관리 가 필요하다고 판단하였다. Network Level의 관리를 위해서는 도로 표면 전부분의 Texture를 빠르게 측 정할 수 있어야 한다. 본 연구에서는 Porosity Index를 활용하여 도로 표면의 Texture를 측정하였다. 측 정한 Porosity Index를 현재 사용 중인 마찰력 측정방법과의 관계를 확인하기 위해 기존의 마찰력지수 (Skid Number)와 도로공극량지수(Road Porosity Index)와의 상관성을 분석하였다.

허용공차와 삼각형의 수의 최소화를 고려한 임의 곡면의 삼각화를 위한 일반적 접근방법 ( A General Approach to Tesellation of Arbitrary Surfaces into Minimum Number of Triangles Satisfying the Required Geometrical Tolerance )

이민철,전만수 대한기계학회 1999 대한기계학회 춘추학술대회 Vol.- No.-

Stem Cell Dynamics in an Experimental Model of Stroke

이민철,Chun-Yan Jin,김형석,김재휴,김명규,Hyoung-Ihl Kim,Young-Jin Lee,Young-Jun Son,김영옥,우영종 전남대학교 의과학연구소 2011 전남의대학술지 Vol.47 No.2

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin+NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin+NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin+ NSCs in the ipsilateral cortex and CC increased at 12hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.

공공조달 성과가 중소기업의 성장에 미치는 영향

이민철,정태현 한국중소기업학회 2018 中小企業硏究 Vol.40 No.4

This study focuses on the role of demand among growth drivers of small and medium enterprises. In particular, this study regards participation in the public procurement programs as a particular form of demand shock. Then we hypothesize that the higher the procurement dependency, the higher the growth rate. We discuss the following mechanisms: public relations and signaling effects, stimulation of technology and quality, mitigating effects of market uncertainty, and economies of scale and learning effects. As a result of analyzing and 644 participating SMEs of Korea's Excellent Product Designation Policy from 2011 to 2016, we found a supporting evidence for the hypothesis. However, the growth effects of the public procurement participation tend to weaken over time. In conclusion we discuss the contributions and limitations of this study on the literature about the role of demand on firm growth, on one hand, and demand-oriented public procurement, on the other hand. 본 연구는 중소기업의 성장을 추동하는 요인 중 수요의 역할에 주목한다. 특히, 본 연구는 조달청의 우수조달 물품 지정기업의 조달실적을 수요충격의 특수한 형태로 보고 조달의존도가 높은 기업일수록 성장률이 높을 것이라고 주장한다. 그 논거로 공공조달의 홍보 및 신호효과, 기술 및 품질 향상 자극효과, 시장 불확실성 완화효과, 규모의 경제와 학습효과를 논한다. 2011년부터 2016년까지 한국의 우수조달 지정제도의 수혜기업 644개에 대한 자료를 새로이 구축하여 실증 분석한 결과, 기업의 이질적 개체효과를 통제하고서도 공공조달 납품실적이 매출 대비 높은 기업일수록 향후 민간시장에서의 매출 성장률이 그렇지 않은 기업보다 높다는 증거를 발견했다. 단, 이와 같은 성장효과는 시간이 지남에 따라 약화되는 경향이 있음도 확인했다. 결론에서는 중소기업 성장과 수요에 관한 학술적 논의, 수요지향형 공공조달의 중요성에 관한 학술 및 정책적 논의에 대한 본 연구의 기여와 한계점을 논하며 마무리한다.

Bilateral Control Based Rupture Protection Method in Surgical Robot Using Improved Master Device

이민철,강주석,윤성민 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.4

A surgeon using a da Vinci surgical robot cannot feel the touch of the tissue on the tip of the surgicalinstrument because the robot only depends on the visual feedback information. This problem can result in medicalaccidents, such as ruptured organs. To solve this problem, this paper suggests a method for recognizing organrupture and an organ protection method using the sensorless force feedback for feeling a reaction force on theinstrument tip. In previous research, a cable-conduit master device was developed to use a haptic system. Thispaper improved a master device for handling the slave. The rupture phenomenon was analyzed by experiments. The thresholds with respect to the organ to protect were settled. The bilateral control-based experimental resultsshowed that the organ is protected.

수두증 치료에서 Medos Hakim Programmable Valve의 유용성

이민철,이정길,김재휴,김현우,김태선,정신,김수한,강삼석,이제혁 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.12

레이다처리장치 시험장비의 데이터 처리방안

이민철,김용민 한국군사과학기술학회 2018 한국군사과학기술학회지 Vol.21 No.6

To develop and check a Radar Processor Unit, checking the function and performance of the requirement is very important factor in developing Radar. General methods for verifying the Radar is simulation test, environment linkage test and field operation test, firstly, in case of requirement analysis phase, verify Radar algorithm and design by using mathematical method based simulation test method, and secondly, in case of unit test and integrated test phase, Test Equipment is set to simulate radar environment in the lab to verify radar function and performance. Lastly, field operation test phase is carried out to confirm the function and performance after it is mounted on the actual equipment. To successfully develop Radar Processor Unit, using the method of field operation test method after sufficient test cases are tested in radar environmental interlocking method in order to save cost and testing period and because of this reason, development of the Radar Processor Unit Test Equipment is becoming very important factor. In this paper, we introduce the concept of test equipment development and important factors in test equipment, which are target simulation, data processing and device interlocking.

전신적인 Methotrexate 치료를 받은 자궁외 임신환자에서 질식 도플러초음파를 이용한 치료효과의 판정

이민철,차상헌,이임순,조태호 대한산부인과학회 1992 대한산부인과학회 학술대회 Vol.69 No.-