휴대폰 카메라용 자동초점 구동기의 충격해석

이성민,김봉석,송준호,이수훈,이혜진,이문구,송준엽,이창우 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

Recently, the robustness against daily impact is important according to portablization and downsizing of mobile electronics. Especially, almost parts of cellular phone should undergo drop test when they fall 1.5 m above ground. This test simulates the case when cellular phone slips through user's fingers while he is talking on the phone. This paper studies a drop test of auto focusing (AF) actuator for camera module in cellular phone. This component is composed of voice coil motor (VCM) as an actuator and leaf spring as a guide and suspension. The leaf spring's deformation is essential for the test because its permanent distortion disables the focusing, and then, a high quality photograph cannot be obtained. Up to now the drop test has been carried out after fabricating real AF actuator. We propose a dropt test model which simulates the drop test based on finite element analysis. This model makes us enable investigate the stress acting on the clamping and curved parts of leaf spring. Stress over Von Mises criterion lets the spring deformed permanently, and then AF actuator malfunctioned, It helps us to design and modify AF actuator without manufacturing the real product. And also, it saves the time and cost for the development of new products.

가상공간의 가공 공정과 상태 구현에 관한 연구

이수훈,김봉석,홍민성,김종민,JUN NI,박상호,송준엽,이창우,하태호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

This paper presents virtual machining system in order to realize turning process in virtual space. A reliable virtual turning process simulation was developed based on the surface shaping system which is capable of considering geometric model, thermal error model, and vibration model. Accuracy of surface shape resulting from proposed machining simulator was verified experimentally. This paper also developed the watchdog agent that continuously assessed, diagnosed, and predicted performance of products and machines in machining. The Watchdog agent extracted feature signal using time-frequency analysis among various signals from multi-sensor and evaluated machining condition using performance confidence value.

매크로/마이크로 레벨 볼트 결합 구조물에서의 실험적/해석적 방법을 통한 시스템 특성 비교

김봉석,이성민,이문구,이수훈,Jun Ni,송준엽,이창우,하태호 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

As the micro technology and miniaturization of a structure and component in the last couple of decades have been concretely realized, the understanding of structural and dynamic characteristics and prediction of dynamic behavior are indispensable to the miniaturized structures and micro machines. This paper shows the effect of dynamic characteristics in bolt-jointed structures by comparing natural frequencies and mode shapes between macro and micro-scale beams through experimental modal analysis and finite element analysis with a1 8 test models by materials, by size, and by joining condition; that is, SS41 and A16061-T651, micro and macro, and monolithic beam and bolt-jointed beam.

Pneumatosis intestinalis and portal venous gas secondary to gefitinib therapy for Lung adenocarcinoma

( Joo Young Lee1 ),( Hye-suk Han ),( Sung-nam Lim ),( Young Kwang Shim ),( Yong Hyeok Choi ),( Ok-jun Lee ),( Ki Hyeong Lee1 ),( Seung Taik Kim ) 대한내과학회 2011 대한내과학회 추계학술대회 Vol.2011 No.-

初期 缺陷形狀에 따른 表面龜裂傳播 特性에 關한 硏究

李龍福,金鍾鉉,李錫俊 弘益大學校 1990 弘大論叢 Vol.22 No.2

In this study, the diameters and depths of the intial surface crack configuration on the specimen was discharge processed differently and considered about propagation behavior and fatigue lifetime of the surface fatigue crack in each case. The result of this study are Summerized as follow; 1. Under the given constant condition, aspect ratio is regular in surface crack propagation, and early its differenceis large according to the initial surface crack configuration but it shows the same change aspect according to the propagation of the crack. 2. In general, for constand initial crack depths we may expect that initial crack lifetime is increased as diameter of specimen is increased because of relaxation of the stress concentration. Practically, however it is different according to the crack. 3. Early, Surface crack configuration has semi-circle and it has semi-elliptical according to crack propagation. 4. When the initial surface crack aspect ratio is in the range of 5∼6, the initial surface crack is propagated to inner surface under the condition, which ratio is smaller than the range. In the ratio is lager than that range, crack is propagated to outer surface.

서비스산업의 점포愛顧 요인간 중요도 파악에 관한 연구

이준석,윤민석 여수대학교 1999 論文集 Vol.14 No.1

The purpose of this study is to explore store patronage factors in the service industry and to analyze their importances. The research design of this study incorporates two phases ; structuring a hierarchical factor model and evaluating composed factors. The Analytic Hierarchy Process is employed to produce objective priorities from subjective judgments. The empirical survey reveals that the location-related factor is the most important, out of four factors, and is almost equivalently followed by the product-related factor. The results of this study would contribute to solving location problems in the service industry. v

Clozapine-유발성 무과립구증의 G-CSF치료경험 1례

이준석,김광일,김인순 大韓神經精神醫學會 1997 신경정신의학 Vol.36 No.4

저자들은 국내 CPMS하에서 최초로 발생한 clozapine-유발성 무과립구증 환자에게 G-CSF를 투여하여 성공적으로 치료한 경험을 보고하였다. Clozapine-유발성 무과립구증의 발생원인은 아직 명확하지는 않으나, HLA 표현형 등의 면역학적 기전과 desmethylclozapine등의 세포독성 기전이 연구되고 있다. 다만, 최종적 공통 경로가 골수내의 골수성 전구세포의 증식억제라는 것은 분명하며, 이것이 CSF사용의 이론적 근거가 된다. CMPS를 통하여 매주 백혈구 수치를 측정하도록 하고 있으나, 최근에도 clozapine-유발성무과립구증의 발생률은 약 1%로 알려져 있으며, 무과립구증의 발생시 급격한 발생 양상, 연장되는 경과, 골수성 전구세포의 부재 등의 특징들로 인하여 2차 감염으로 인한 사망률이 매우 높은 치명적인 상태에 빠지게된다 그러므로, clozapine사용 환자의 선정에 있어서, 고령 및 여성 등 위험인자를 고려하여야 할 것이며, 사용 중에는 백혈구의 스파이크 등 예측인자에 대한 주의가 요망된다고 하겠다. Clozapine-유발성 무과립구증이 발생하면, 우선 골수생검 등을 통한 정확한 진단이 이루어져야 하며, 즉각적 clozopine의 투약중단, 혈액학 및 감염학 전문의에게 자문의뢰하고, 2차감염을 막기 위한 격리 및 예방적 항생제 투여 등과 함께, G-CSF나 GM-CSF투여를 통한 무과립구증 기간 단축 등의 적극적인 치료가 반드시 요망된다. The authors present a successful treatment case of clozapine-induced agranulocytosis with granulocyte colony-stimulating factor(G-CSF). It is the first case in Korean that occurred despite proper monitoring by the Clozaril Patient Monitoring System(CPMS) and full clinical vigilance. The mechanism of clozapine-induced agranulocytosis is unknown. Various studies are attempting to identify the pathogenic mechanism involved, and whether it is immunologic like human leukocyte antigen(HLA)-associated or toxic like desmethylclozapine-associated. However, it is clear that the final common pathway is suppression of myeloid proliferation in the bone marrow. The theory that clozapine-induced agranulocytosis is caused by suppression of colony forming units of granulocytes and macrophages(CFU-GM) forms the rationable for the use of GCSF or GM-CSF. The management of clozapine-induced agranulocytosis should include accurate diagnosis of agranulocytosis through bone marrow examinations, prompt discontinuation of clozapine, consultation with a hematologist, infectious disease specialist. Reverse isolation and administration of prophylatic antibiotics are need for prevention of secondary infection. A potential decrease of recovery time achieved by G-CSF obviously lowers the risk of secondary infectious disease.

우리나라 기업의 해외현지법인설립 공시가 주주부에 미치는 영향

이준석,조정원 東亞大學校 1996 東亞論叢 Vol.33 No.-

Modern corporate finance theory assumes that a film undertakes investment projects to increase its value or the value of the film to maximize shareholder wealth. It is assumed that the firm's expected net present value will have a positive impact on shareholder wealth if the firm choses to invest in an foreign direct investment(FDI). The purpose of this study is to test the impact of multinational expansion through subsidiaries on market vague fluctuations to determine whether foreign direct investment is a value-creating investment. Also, this study tests country diversification effects and investment size effects. The samples used in this study is 62 samples that have made FDI. in 1990∼1994.6 period. The results are shown as follows, First, according to the study, shareholders of firms engaging in foreign direct investment experience normal returns or negative abnormal returns at the announcement of the investment, Therefore the do not support the value creation hypothesis. Second, the shareholders of Korean firms engaging in FDI experience no significant positive returns. The Empirical results support the survival strategy hypothesis. Third, the Empirical results show that FDI in a developed and less developed countries do not yield significant abnormal returns to investing firms' shareholders. Thus, the results do not support the country diversification effects hypothesis.

좌측흉수로 발현된 Boerhaave 증후군 1예

이준,변유미,조민근,조주연,원경준,김영대,박찬국,김만우,유재근,서홍주,이석기 朝鮮大學校 附設 醫學硏究所 2008 The Medical Journal of Chosun University Vol.33 No.2

구토 후 발생한 토혈을 주소로 내원한 환자에서 좌측 늑막 삼출 동반 시 식도 파열의 가능성을 고려하여 흉수 천자 및 지속적인 흉부 단순 촬영의 추적관찰이 필요하며 식도 파열이 배제된 후 환자의 생체 징후 및 토혈 양을 파악하여 내시경 검사 시기를 신중히 결정하는 것이 좋을 것으로 생각된다. 본 증례는 토혈을 주소로 내원하여 Mallory-Weiss 증후군 의심 하에 내시경을 통한 치료 시행 후 추적 관찰에 의해 진단된 Boerhaave 증후군을 경험하였기에 보고하는 바이다. Boerhaave's syndrome is a spontaneous perforation of the esophagus most commonly resulting from a sudden increase in intraesophageal pressure combined with negative intrathoracic pressure caused by straining or vomiting. Surgery should generally be performed within 24 hours because mortality approached 30 to 50 percent in which surgery was delayed. Therefore, early diagnosis and prompt surgical repair are critical for survival. We have experienced a case of Boerhaave's syndrome in a patient presenting with hematemesis with left pleural effusion without any signs or symptoms of pneumomediastinum or pneumothorax.

在庫管理 모델의 選擇을 위한 知能的 意思決定支援시스템

이준석 여수대학교 1997 論文集 Vol.11 No.2

In these competitive times, there is great pressure to improve customer service, and at the same time to find cost savings wherever possible. Advancing computer technology has resulted in the greatest impact on business since the industrial revolution. The inventory control is no exception to this phenomenon. Decision support system(DSS) and expert system(ES) represent one of the most interesting sub areas of the use of information technology in inventory control. Especially, Intelligent decision support system(IDSS), integrated ES and DSS, was significant technology in inventory parts. Therefore, this paper developed prototype IDSS for inventory control method selection. The focus is on the development of a simple, user-friendly tool that can be used effectively by managers to increase the cost-effectiveness of their inventory system. The IDSS was constructed by using the tools of ART-IM expert system shell, CLIPER, FORTRAN 77, and SLAMSYS simulation language. The scope of this paper is limited to the single-item, single-location problems.