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.

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.

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.-

토양환경지도 자료를 이용한 콩밭 토양의 화학성 비교

박지숙,이민진,정재원,김미혜,이서연,지윤미,한준호,김유학,공명석,한광현,노희명 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

It is important to interpret the soil chemical properties in order to effectively manage the farmland. This study was conducted to investigate the soil chemical properties of upland soybean field according to the soil series at 32 upland fields located in the parts of Gangwon-do. Soil sampling sites were selected by using the National Statistics DB and KSIS DB that is a soil environment information system provided by the Rural Development Administration. Soil samples were collected from 0~15 cm of top soil before seeding or transplanting, air-dried, passed through a 2 mm sieve, and analyzed for soil pH, EC, organic matter, available phosphorus (P2O5), exchangeable potassium, exchangeable calcium and exchangeable magnesium. The average chemical properties have exceeded the each nutrient optimum range level of RDA, except the organic matter in experimental soil 2015. And despite application of conventional fertilization, each soil series nutrient contents were change respectively. The results of this study suggest that conventional fertilization should be applied based on the analysis about the amount of accumulated nutrient contents in the soil.

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.

공구 수명의 신뢰성 예측 프로그램 개발

이수훈,김봉석,강태한,송준엽,강재훈,서천석 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool life was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool life is being developed as one of reliability assessment programs to for the machine tools.

Cariogram을 이용한 모자간 우식활성도의 상관성 및 우식위험요소 평가

이석우,송제선,최병재,최형준,이제호 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

영유아기 치아우식증은 복잡하고 다인자적 질환으로 숙주 및 미생물, 식이, 시간 등의 위험요소에 의해 질환이 진행된다. 이 중 미생물로 대변되는 Streptococcus mutans(S. mutans)는 우식 개시에 있어 중요한 역할을 하며, 어머니를 통한 수직 감염이 잘 알려져 있다. 영유아기의 어머니를 통한 조기 감염은 향후 유치열기 우식 발생과 높은 연관성을 나타내므로 우식위험요소에 대한 조기 파악은 미래의 치아우식증 예방에 있어 매우 중요하다. 최근 치아우식증의 원인 및 이에 미치는 요소들에 대한 연구가 활발하게 이루어지면서 우식 진행에 대한 정확한 예측을 위한 여러 가지 우식위험도평가(caries risk assessment) 도구가 개발되었는데, 이 중 대표적인 한 가지가 Cariogram이다. Cariogram은 개인의 우식활성도 및 우식위험요소(caries risk factor)의 상호작용을 그래프로 나타낸다. 이번 연구의 목적은 3~5세의 중증 유아기우식증(Severe Early Childhood Caries; S-ECC)에 해당되는 어린이들과 그들의 어머니 사이에서 우식관련타액검사 및 최근 개발된 Cariogram을 이용하여 S. mutans의 수준 및 우식활성도에 대한 상관관계가 존재함과 우식위험요소 간의 연관성을 파악해 보았는데, 이를 통해 다음과 같은 결론을 얻을 수 있었다. 1. 중증 유아기우식증을 보이는 어린이에서 구강 내 존재하는 Streptococcus mutans의 수준은 비우식군보다 높았다(p<0.05). 2. 모자간 구강 내 존재하는 Streptococcus mutans 수준은 상관관계를 보였다(p<0.05). 3. 모자간 우식활성도를 Cariogram을 통해 측정해 본 결과 상관관계를 보였다(p<0.05). 4. 우식활성도에 미치는 우식위험요소는 어린이에서 숙주요소가 가장 큰 영향을 주는 것으로 나타났다. 이상의 결과로 S. mutans가 향후 치아우식증 발생 가능성을 예측하는데 있어 유용한 우식위험요소가 될 수 있으며, Cariogram을 통한 향후의 우식진행과 관련된 여러 가지 우식위험요소가 예측 가능하므로 이에 대한 조기 대처 및 예방적 처치가 가능하리라 사료된다. Dental caries during infantile and early childhood period is a complex disease resulting from multiple caries factors. Streptococcus mutans(S. mutans) plays a critical role in the initiation of caries, and its early transmission through mothers provides a strong etiologic factor for future development of caries in the primary dentition. Therefore, early detection of caries risk factor is important for prevention of caries. Recent studies about etiologic factors of caries have brought advent of various tools for caries risk assessment in order to predict progress of caries more accurately. Cariogram is a common tool for caries risk assessment, which illustrates present caries risk assessment and correlation of caries risk factors for an individual graphically. The aim of this study was to assess if there is any correlation in the level of S. mutans and caries activity and to verify the effect of caries risk factors between children with age ranging from 3 to 5 years with severe early childhood caries(S-ECC) and their mothers using caries-related salivary test and Cariogram. The results of this study were as follows. 1. Children with S-ECC had a statistically higher level of Streptococcus mutans compared to caries-free children(p<0.05). 2. There was significant correlation between mothers and their children in the aspect of the level of Streptococcus mutans(p<0.05). 3. When caries activity was assessed using Cariogram, significant correlation between mothers and their children was found(p<0.05). 4. When each caries risk factor was evaluated for its affect on caries activity, host was more influential factor compared to microorganism and diet in children. Based on these results, we could conclude that assessing the level of S. mutans can be an effective tool for predicting possibility of caries formation in future. Since prediction of future caries progression and evaluation of caries risk factor became possible with Cariogram, we may conduct early and preventive measures for treatment of caries.

상악 정중부에 역위 매복된 과잉치의 악골 내 이동

이석우,이제호,김성오,최형준,손홍규,최병재 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.4

과잉치는 상악 정중부에서 주로 발견되며,과잉치의 발생 기전은 유전적 또는 환경적 원인에 의하여 치배 형성기 동안에 정상 치판의 비정상적 증식에 의한 것으로 보고되었다. 과잉치로 인한 합병증으로는 인접 영구치의 맹출 장애와 전위,회전,정중이개,비강으로의 맹출,낭종 형성 등 이 있다. 과잉치를 외과적으로 발거하기 위한 시기에 대해서는 논란이 되고 있다. 인접치의 배열과 맹출 장애,전위를 야기할 수 있기 때문에 조기에 발거하자는 견해와 어린이의 행동 조절 및 인접 영구치의 치근 형성 정도를 고려하여 8~l0세 이후에 발거 하자는 견해가 있다. 후자와 같이 외과적 발거 시기를 연기할 경우,역위 및 수평 매복된 과잉치는 악골 내에서 비강 또는 경구개,소구치 부위 등으로 이동할 수 있으며,과잉치의 이동과 전상악골의 수직고경 증가로 인하여 외과적 발거 시 난이도가 높아질 수 있다. 따라서,역위 및 수평 매복된 과잉치의 외과적 발거 시기를 결정하기 위하여 연기하는 경우에 과잉치의 악골 내 이동을고려해야한다. 이 증례는 상악 정중부에 역위 매복된 과잉치가 있어서 내원한 6~7세의 어린이에서 과잉치의 외과적 발거 시기를 결정하기 위하여 주기적인 방사선 학적 검사로 관찰하던 중에 2~3년 후 과잉치 위치가 악골 내에서 초진 시 위치로부터 이동된 경우로 이를 보고하는 바이다. Supernumerary teeth are frequently found in the anterior portion of the maxilla and develop as a result of abnormal proliferation of the dental lamina during tooth germ formation, caused by genetic or environmental factors. They may result in various complications, such as eruption interference, displacement, rotation of adjacent teeth, diastema, eruption into the nasal cavity, and development of dentigerous cyst. The optimal time for surgical extraction of supernumerary teeth has been a controversial issue. Someone prefer early surgical extraction because supernumerary teeth can cause eruption interference and displacement of adjacent teeth, eventually altering occlusion. Others prefer to delay surgical extraction until 8~10 years of age in consideration of root maturation of the adjacent teeth and also patient's behavior. When surgical extraction of supernumerary teeth is postponed, there is possibility that impacted supernumerary teeth in the inverted or horizontal position move toward the nasal cavity, hard palate, or premolar area. When such intraosseous tooth migration is combined with the vertical growth of the maxilla. surgical approach becomes even harder. Therefore, possibility of intraosseous tooth migration should be considered as an important factor when deciding appropriate time for surgical extraction. We are presenting cases of mesiodens which showed intraosseous migration during 2~3 years of follow-up period since the first diagnosis had been made at the 6~7 years of age.

VOD 서비스에서의 새로운 스트림 할당 기법

이준화,김영환,박재현,박현민,최병석 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

Generally, in a VOD(Video On Demand) systems, batching technique is often used to improve throughput. Since subscribers to VOD services tend to renege their requests as the latency becomes large, an optimal stream allocation scheme should consider not only batching size but also renege rate, service latency and fairness between different programs. In this paper, we propose a new stream allocation scheme, which shows improvement in fairness and reduction in renege rate and service latency compared with other well known schemes. When 2 or more streams are available in the VOD server, each streams are allocated based on different program selection policies. Using this approach effectiveness of stream usage can be improved.