교육기회의 평등에 대한 고찰: J.Rawls와 R. Nozick을 중심으로

손준종 고려대학교 교육문제 연구소 1995 敎育問題硏究 Vol.7 No.-

방사형기저함수망을 이용한 열간 사상압연의 압연하중 예측에 관한 연구

손준식,이덕만,김일수,최승갑 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.6

A major concern at present is the simultaneous control of transverse thickness profile and flatness in the finishing stages of hot rolling process. The mathematical modeling of hot rolling process has long been recognized to be a desirable approach to investigate rolling operating practice and the design of mill equipment to improve productivity and quality. However, many factors make the mathematical analysis of the rolling process very complex and time-consuming. In order to overcome these problems and to obtain an accurate rolling force, the predicted model of rolling force using neural networks has widely been employed. In this paper, Radial Basis Function Network(RBFN) is applied to improve the accuracy of rolling force prediction in hot rolling mill. In order to verify and analyze the performance of applied neural network, the comparison with the measured rolling force and the predicted results using two different neural networks-RBFN, MLP, has respectively been carried out. The results obtained using RBFN neural network are much more accurate those obtained the MLP.

연속냉간압연의 두께제어 모델 개발에 관한 연구

손준식,김일수,권욱현,최승갑,박철재,이덕만 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.5

The quality requirements for thickness accuracy in cold rolling continue to become more stringent, particularly in response to exacting design specification from automotive customers. One of the major impacts from the tighter tolerance level is more unusable product on the head end and tail end of tandem mill coils when the mill is in transition to or from steady state rolling condition. A strip thickness control system for a tandem cold steel rolling mills is composed with blocked non-interacting controller and controllers for strip thickness and tension control of each rolling stands. An intelligent mathematical model included an elastic deformation of strip has been developed and applied to the field in order to predict the rolling force. The simulated results showed that the effect of elastic recovery should be included the model, even if the effect of elastic compression was not important.

On-line 학습 신경회로망을 이용한 열간 압연하중 예측

손준식,이덕만,김일수,최숭갑 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

In the face of global competition, the requirements for the continuously increasing productivity, flexibility and quality(dimensional accuracy, mechanical properties and surface properties) have imposed a major change on steel manufacturing industries. Indeed, one of the keys to achieve this goal is the automation of the steel-making process using AI(Artificial Intelligence) techniques. The automation of hot rolling process requires the developments of several mathematical models for simulation and quantitative description of the industrial operations involved. In this paper, a on-line training neural network for both long-term learning and short-term learning was developed in order to improve the prediction of rolling force in hot rolling mill. This analysis shows that the predicted rolling force is very closed to the actual rolling force, and the thickness error of the strip is considerably reduced.

On-line 학습 신경회로망을 이용한 열간 압연하중 예측

손준식,이덕만,김일수,최승갑 한국공작기계학회 2005 한국생산제조학회지 Vol.14 No.1

In the face of global competition, the requirements for the continuously increasing productivity, flexibility and quality(dimensional accuracy, mechanical properties and surface properties) have imposed a major change on steel manufacturing industries. Indeed, one of the keys to achieve this goal is the automation of the steel-making process using AI(Artificial Intelligence) techniques. The automation of hot rolling process requires the developments of several mathematical models for simulation and quantitative description of the industrial operations involved. In this paper, an on-line training neural network for both long-term learning and short-term learning was developed in order to improve the prediction of rolling force in hot rolling mill. This analysis shows that the predicted rolling force is very closed to the actual rolling force, and the thickness error of the strip is considerably reduced.

전단자극 시 나트륨-칼슐 교환체 활성에 의한 횡방향 심방 근세포 Ca2+ 웨이브의 발생

김준철, 왕준, 손민정, 김경희, 우선희 충남대학교 약학대학 의약품개발연구소 2017 藥學論文集 Vol.32 No.-

In the present study, we investigated possible mechanism for the triggered global CaH wave from local Ca2+ wave in atrial myocytes under shear stress. Shear stress was applied onto single cells isolated from rat atria and two-dimensional confocal Ca2+ imaging was performed to measure Ca2+ signal. Shear stress of 16 dyn/cm2 induced local Ca2+ wave, which was followed by a rapid transverse global Ca2+ wave inhibition of Na + -ci+ exchange using KB-R7943 suppressed the occurrence of rapid transverse wave ob served under shear stress, but not the shear-induced local wave. in the presence of this chemical local wave was developed to global wave under shear stress which results in slower time to peak of peripheral and central CaH transients. As the preceding local Ca"+ wave signal was higher, the latency of the occurrence of transverse global wave was shorter, suggesting Ca2+ dependence of transverse Ca2+ wave. The results sug-gest that shear stress may activate Na+ -Ca2+ exchange via local CaZ+ wave, triggering the rapid global Ca2+ wave

Monte Carlo 시뮬레이션을 이용한 이온 주입시의 점결함 분포의 계산

손명식,이준하,변기량,황호정 중앙대학교 기술과학연구소 1995 기술과학연구소 논문집 Vol.25 No.-

이온 주입시의 점결함 분포를 간접적으로 계산하기 위해 단결정 실리콘에서의 3차원 이온 주입 시뮬레이터인 TRICSI (TRansport Ions in Crystal Slilicon) Monte Carlo 코드를 확장하여 Boron 이온 주입시의 에너지와 dose에 따른 불순물(particle) 및 점결함 분포(point defect)를 계산하였다. 결함 분포는 Modified Kinchin-Pease equation을 단결정 실리콘에 적용하여 displacement damage에 의해 발생한 Frenkel Pair(vacancy-interstitial)분포를 계산하였으며 이온 주입시의 웨이퍼 온도에 의한 Frenkel Pair 소멸 효과는 고려하지 않았다. 계산 결과는 3차원 각면으로의 2차원 투영 불순물 농도로 표현하고 주입된 dose와 에너지에 다른 마스크 주입시의 에너지 및 dose 의존성 도펀트 분포와 이에 따른 damage 분포를 이해하는 데 중요한 정보가 될 것으로 기대된다. We extended our ion implantation simulator, TRICSI (TRansport lons in Crystal Slilicon) Monte Carlo(MC) code, and indirectly calculated particle and its generating point defect distributions depending on energy and dose during boron implantation into <100> single0crystal silicon. The point defect distribution of Frenkel Pair(vacancy-interstitial) was abtained by applying the modified Kinchin-Pease equation, which usually uses in MC simulation in amorphous target, to MC simulation in crystalline silicon. We did not considered the annihilation of Frenkel Pairs due to wafer temperature. The calculated results were projected onto each free-dimensional plane, presented as two-dimensional concentration profile on it. The particle concentration profile was presented with typical open mask structure. We expect that these results help understand the dopant and its generating damage distributions depending on energy and dose during boron implantation.

작은 피질하 병변에 대한 정위적 개두술 및 경-구 접근법

손병철,김문찬,이관성,박춘근,홍용길,강준기 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.12

방사형기저함수망을 이용한 표면 비드폭 예측에 관한 연구

손준식,김인주,김일수,김학형 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

Despite the widespread use in the various manufacturing industries, the full automation of the robotic CO₂ welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, productivity, microstructure and weld properties in arc welding processes have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on the specific experimental results. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an Radial basis function network model to predict the weld top-bead width as a function of key process parameters in the robotic CO₂ welding. and to compare the developed model and a simple neural network model using two different training algorithms in order to verify performance. of the developed model.

상지 단순반복작업 근로자의 수근관 증후군 유병률에 관한 조사

손지언,장태원,김윤규,홍영습,정갑열,김동일,이강진,하남진,김상범,김준연 대한산업의학회 2001 대한직업환경의학회지 Vol.13 No.3

목적 : 본 연구는 수근관 증후군의 발생위험이 높은 작업형태에 종사하는 상지 단순반복작업근로자로서 육류 및 어류 가공 사업장과 목재소 근로자에서 근전도검사를 이용하여 수근관 증후군의 유병률을 조사하고자 하였다. 방법 : 상지 단순반복작업근로자로서 육류 및 어류 가공 사업장 근로자 69명과 목재소 근로자 17명을 실험군으로, 관리직, 경리, 경비등 상지의 단순반복작업이 없는 근로자 28명을 대조군으로 선정하여, 작업적 및 병력조사, 이학적 검사와 근전도검사를 통해 수근관 증후군의 유병률을 조사하였다. 결과 : 수근관 증후군의 유병률은 육류 및 어류 가공 사업장과 목재소에서 각각 26.09 % (18명)와 29.41 %(5명)로 조사되었으며, 육류 및 어류가공사업장과 목재소 근로자를 '7년 이상과 미만의 작업기간'으로 층화하여 비교한 결과 '상지부위의 통증 호소 유무', 'Visual Analogue Scale(VAS: 총 10점) 4점 이상 여부', 'Tinel teat 양성 유무', 'Phalen test 양성 유무'는 모두 단기 작업근로자군에서 양성의 빈도가 증가되었고 '수근관 증후군 유무'는 장기작업근로자군에서 양성의 빈도가 증가되었다. 결론 : 육류 및 어류 가공 사업장과 목재소의 수근관 증후군 유병률은 각각 26.09 %와 29.41 %로 육류 및 어류 가공 사업장과 목재소는 1996년 OSHA가 지정한 바와 같이 위험한 작업요인이 있는 작업장으로 분류하여 관리되어야 할 것으로 생각된다. Objectives : This study was carried out to survey on the prevalence of Carpal Tunnel Syndrome(CTS) in high risk jobs(meat and fish processing plant and wood plant), by application of Nerve Conduction Study(NCS), a confirmatory diagnostic method. Methods : Experimental group was 69 workers sampled from meat and fish processing plants and 17 workers sampled from wood plants, who were simple, repetitive workers using upper extremities and control group was 28 workers sampled from managers, secretaries and keepers. All employees were examined through work history, physical examination and NCS. Results : 18 workers(26.09%) in meat and fish processing plants, and 5 workers(29.41%) in wood plants had compatible findings to NIOSH diagnostic criteria for CTS. The experimental group had more symptoms (complaint of upper extremities, Visual Analogue Scale ≥4(VAS: total 10 point)), signs(Tinel and Phalen test) and prevalence of CTS than control group(p<0.05). The prevalence of symptoms and signs were higher in short term workers(<7 years), but the prevalence of CTS was higher in long term workers(≥7 years). Conclusions : The prevalence of CTS in meat and fish processing plant and wood plant were 26.09% and 29.41% respectively. Authors propose that meat and fish processing and wood plants should be managed as a risk job category which were designated by OSHA in 1996