입열량이 고변형률 강관 원주 용접부 특성에 미치는 영향

이진우,송우현,서동한,이종섭,Lee, Jin-Woo,Song, Woo-Hyun,Seo, Dong-Han,Lee, Jong-Sub 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.6

SBD (Strain-based design) of pipe lines have gained world-wide attention in recent years. The present research aims to evaluate the fracture characteristics of API (America Petroleum Institute) SBD X100 girth weldment that typically applied for cold climate and deep water offshore, with the focus on the influence of heat input changing with 6kJ/cm and 10kJ/cm from GMAW (Gas Metal Arc Welding). At a low heat input at 6kJ/cm, the weld metal had Multi-phase matrix (Acicular ferrite + Banite + Martensite) that could fill up both fracture toughness and strength as reported previously. Also, the weld metal exhibited 859MPa YS (Yield strength), 108J impact toughness at $-40^{\circ}C$ and 0.52mm CTOD (Crack Tip Open Displacement) at $-10^{\circ}C$. These results can be satisfied with the requirement of API SBD X100 girth weldment and Alaska pipe line project.

TCP over ATM의 성능 개선에 관한 연구

이진우,박기태,김진태,김래진,박인갑,Lee, Jin-Woo,Park, Ki-Tae,Kim, Jin-Tae,Kim, Nae-Jin,Park, In-Kap 한국전기전자학회 1998 전기전자학회논문지 Vol.2 No.1

The Asynchronous Transfer Mode(ATM) networks are being adopted as backbones over various parts of Internet. Also, TCP is one of the most widespread transport protocols, nowadays. It can be used with ATM. But, TCP shows poor end-to-end performance on ATM networks. Effective throughput of TCP over ATM can be quite low when cells are dropped at the congested ATM switch. The low throughput is due to wasted bandwidth as congested link transmits cells from corrupted packets. This paper examines the behavior of TCP over ATM-UBR using EPD switch in a broadband environment. With a threshold close to the buffer size, the buffer can be used more efficiently, but more drops and retransmission occurs. If the threshold is much less than buffer size, efficient is not good, but few drops can happen. Therefore, decision of the threshold is important.

노인들의 건강증진생활양식에 관한 연구 - 전북 농어촌지역을 중심으로 -

이진우,정명수,이춘우,권소희,고광재,정재열,장두섭,송용선,이기남,Lee Jin-Woo,Chong Myung-Soo,Lee Chun-Woo,Kwon So-Hee,Ko Kwang-Jae,Jeoung Jae-Yeal,Jahng Doo-Sub,Song Yung-Sun,Lee Ki-Nam 대한예방한의학회 2001 대한예방한의학회지 Vol.5 No.2

This investigation grasps the level and relevant elements of performance of health promotional activities for the elderly in Korea. It provides fundamental data on health promoting projects targeting the elderly population from farming villages. Hence, this study gropes for an effective approach and measures of health promoting programs. The program needs to be developed with a focus on elderly people from farming villages. In addition, it was carried out in order to provide basic data for development of health projects for local communities. Data gathering was based on survey data targeting patients from the free clinic service. Service was rendered for the residents of farming villages, and conducted at the Offices of CheonBuk Province from October 2000 to December 2000. Analytical results were used to examine the health promotional method for the elderly in the aspect of Oriental Medicine. SPSS 9.0 version as well as T-test and ANOVA were used for survey data analysis. Piersons correlation coefficient was utilized for the relationship for each area, obtaining the following analytical results. 1. The average score for the activities of health promotion was 2.28. Looking at each subcategory, stress management was the highest at 3.65; interpersonal relationship, 3.00; nutrition, 2.55; health responsibility, 2.15; self-realization, 2.03; and exercise was the lowest at 1.89. 2. With respect to lifestyle of the health promotion secondary to general features of elderly people from farming villages, the level of activities of health promoting lifestyle was shown to be higher for males than that of females. Self-realization area was high among males in detailed particulars while the level of execution was high as age decreases in the stress area. 3. Regarding health promoting life style secondary to socioeconomic characteristics, the level of execution was higher for the individuals with a higher level of education and further utilization of spare time. With respect to occupation, the level was highest for people from the fishery. The level decreased in the order of other occupations such as trade, unemployed and agriculture, which was shown to be the lowest. In detailed particulars, it revealed that higher the individuals educational level, the higher the self-realization and stress management areas. The level of interpersonal relationship was the highest among people with little or no education. With respect to self-realization area, the level was highest among the cases where one paid living expenses along with their children. The lowest level of living expenses was seen in the cases where an individual pays for living expenses by himself/herself. There were significant results in all areas except for nutrition areas depending on occupation. The fishery was shown to be the highest. The level of activities was higher as one utilizes more spare time in all areas except for the area of interpersonal relationship.

개에서 prednisolone을 이용한 호산구성 장염 치료 증례

이진우,이선희,임수정,박형진,정대욱,김태신,김덕환,송근호,Lee, Jin-Woo,Lee, Sun-Hee,Lim, Soo-Jung,Park, Hyung-Jin,Jung, Dae-Wook,Kim, Tae-Sin,Kim, Duck-Hwan,Song, Kun-Ho 대한수의학회 2010 大韓獸醫學會誌 Vol.50 No.4

A 7-year-old, castrated male Yorkshire terrier dog with chronic vomiting, and melena lasted for 3 weeks was referred to the Veterinary Medical Teaching Hospital of Chungnam National University. The complete blood counts and serum biochemistry revealed no remarkable findings. Gastrointestinal series revealed irregular margin in small intestinal lumen. After upper gastrointestinal series, erythema of the small intestinal lesions was found by exploratory laparotomy and full-thickness biopsy was performed. Histopathologic examination revealed infiltration of predominantly eosinophils and other inflammatory cells in small intestine. Based on these findings, the dog was diagnosed as eosinophilic enteritis. After 4 weeks medical treatment and hypoallergenic diet, the patient showed no vomiting, melena and other complications.

선원 해상생존교육 실습시설 및 장비의 적정성에 관한 연구

이진우,김이완,이창희,이영호,Lee, Jin-Woo,Kim, E-Wan,Lee, Chang-Hee,Lee, Young-Ho 해양환경안전학회 2017 海洋環境安全學會誌 Vol.23 No.5

STCW협약에 따른 기초안전(재)교육 및 상급안전(재)교육 등과 같은 선원 해상생존교육은 해상에서 비상상황이 발생할 경우 선원들의 생존율을 증대시켜줄 수 있는 필수교육이다. 그리고 IMO 모델코스에 따른 선원안전교육을 효과적으로 수행하기 위해서는 선원들이 다양한 안전장비에 대한 이론 및 실습교육이 병행되는 것이 매우 중요하다. 따라서 이 연구는 IMO 모델코스에서 요구하는 해상생존교육과정에 근거한 실습시설을 파악하고, 국내외 교육기관의 운영 실례를 바탕으로 관련 시설을 비교 분석하여 선원 안전교육시설 개선방안을 다음과 같이 마련하였다. 첫째, 해상탈출설비(슬라이드, 슈트 등) 등과 같은 최신화된 교육장비를 비치하여, 선원들이 다양한 안전장비를 직접 체험할 수 있는 교육환경을 구축해야 한다. 둘째, 조파, 풍동, 강우, 암막장치 등과 같은 해상환경 재현시설의 설치하여 학습자가 현실적인 비상상황을 직 간접적으로 체험해 볼 수 있는 교육환경의 구축해야 한다. 셋째, 체험교육, 시청각교육, 시뮬레이터 교육과 더불어 가상현실 교육장비를 통한 층위별 맞춤교육을 개발하고 확대시킬 필요가 있다. Seafarer sea survival training, such as basic safety refresher training and advanced safety refresher training, in accordance with the STCW Convention, is an indispensable program that can increase the crew survival rate during emergency situations at sea. It is important for crew members to carry out theoretical and practical training with various safety equipment in order to effectively train according to IMO model courses. Therefore, this study suggests the following measures to improve safety training facilities for seafarers by reviewing survival training requirements based on the IMO model course and comparing and analyzing related facilities based on operating cases from domestic and overseas training institutes. First, it is necessary to establish a training environment where seafarers can practice utilizing various, updated safety equipment such as marine evacuation equipment (slides, chutes, etc.). Second, it is necessary to construct an educational environment in which learners can directly or indirectly experience realistic emergency situations by installing marine environment simulation facilities with such equipment as a wave generator, rain fall device, wind generating device, etc. Third, it is also necessary to develop and expand customized training using virtual reality equipment in addition to experiential training, audiovisual training and simulation training.

GHP 배열회수용 이중 쉘-튜브형 배기가스 열교환기의 설계 최적화

이진우,신광호,최송,정백영,김병순,Lee, Jin Woo,Shin, Kwang Ho,Choi, Song,Chung, Baik Young,Kim, Byung Soon 대한기계학회 2015 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.3 No.1

본 논문은 GHP 에 사용되고 있는 이중 쉘-튜브형 배기가스 열교환기의 설계 변수의 변화에 따라 열전달 및 마찰특성 변화를 알아보기 위해 CFD 와 RSM 을 이용하여 최적화를 수행하였다. CFD 해석은 복잡한 형상의 열교환기 해석에 유용한 도구이나, 해석결과를 얻기까지 많은 시간이 소요된다. 이러한 해석시간을 줄이고, 유용한 결과를 얻기 위해 RSM 과 병행하여 최적화 설계를 진행하였다. 시뮬레이션 결과를 이용한 RSM 해석결과, 배플 6 개, 튜브 25 개에서 최적화되었으며, 기존 보다 차압 및 열전달 성능이 약 12.2% 개선되었다. 이러한 CFD 와 RSM 을 이용한 최적화 기법은 다양하고 복잡한 형상의 열교환기 해석에 유용함을 확인하였다. In this paper, we performed the design optimization dual-shell and tube heat exchanger on exhaust waste heat recovery for gas heat pump using CFD and RSM. CFD analysis is useful to design the complex structure such as double shell and tube heat exchanger. By computer simulation, engineers can assess the feasibility of the given design factors and change them to get a better design. But if one wishes to perform complex analysis on the simulation, such dual-shell and tube heat exchanger for GHP, the computational time can become overwhelming. CFD is powerful but it takes a lot of time for complex structure. Therefore, the CFD analysis is minimized by the optimization using the RSM method. As a result, the number of baffle and tube are optimized by 6 baffles and 25 tubes for heat transfer and flow friction. And then pressure drop and heat transfer is improved about 12.2%. We confirm the design optimization using CFD and RSM is useful on complex structure of heat exchanger.

동수압을 고려한 지진해일 최대침수예상구역 예측

이진우,한세종,조용식,Lee. Jin Woo,Han. Sejong,Cho. Yong-Sik 한국방재학회 2013 한국방재학회논문집 Vol.13 No.3

본 연구에서는 동수압을 고려한 수치모형을 이용하여 임원항에서의 최대침수영역을 예측하고 이를 바탕으로 최대침수예상도를 작성하였다. 최근 발생한 동일본 지진해일로 인하여 지진해일 방재대책에 대한 관심이 높아지고 있는 실정이다. 본 연구에서 사용한 수치모형은 기존의 지진해일 전파모형을 사용하였으며, 해안지역에서는 동수압을 고려한 범람모형을 사용하였다. 3개의 역사 지진해일과 11개의 가상 지진해일을 이용하여 임원항에서의 최대침수영역을 예측하였고, 예측된 최대침수영역을 이용하여 최대침수예상도를 작성하였다. 작성된 최대침수예상도는 지진해일 방재와 관련하여 유용하게 사용될 수 있을 것으로 판단된다. Predicted maximum inundation area with a three-dimensional hydrodynamic pressure model is developed in this study. Recently, the tsunami disaster is increasingly interested due to the East Japan Tsunami. The numerical model is composed of propagation model and inundation model. For the predicted inundation area, hydrodynamic pressure model is employed. Predicted maximum inundation area at Imwon port is calculated for 3 historical tsunamis and 11 virtual tsunamis. When dealing with tsunami disaster, the produced maximum inundation area can be utilized.

저항클래딩법을 응용하여 형성된 내마모성 WC-6.5Co 클래딩층의 미크로조직 특성

이진우,고준빈,이영호,Lee, Jin-Woo,Ko, Jun-Bin,Lee, Young-Ho 대한용접접합학회 2007 대한용접·접합학회지 Vol.25 No.3

This study deals with characterizations of microstructure and wear performance of a cladding layer, product on 1.9 mm-thick mild steel plate by the electric resistance welding, of composite metal powder of Coarse WC-6.5%Co and high carbon alloy (SHA). The cladding layer was examined and tested for microstructural features, chemical composition, hardness, and bondability. The cladding layer have two different matrix were observed by an optical microscope and EPMA. The one was the coarse WC-6.5Co structure. The other was the melted SHA with surrounding the WC-6.5Co structure. The hardness of WC-6.5Co was 1210HV. The hardness of SHA was 640HV.

지상파 DMB 모뎀용 R2SDF/R2SDC 하이브리드 구조의 FFT/IFFT 코어 설계

이진우,신경욱,Lee Jin-Woo,Shin Kyung-Wook 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.11

본 논문에서는 지상파 DMB 단말기 모뎀의 핵심 기능블록으로 사용되는 FFT/IFFT 코어(FFT256/2k)를 설계하였다. 설계된 코어는 Eureka-147 전송 규격에 명시된 4가지 전송모드를 지원할 수 있도록 256/512/1204/2048점 FFT/IFFT를 선택적으로 수행하도록 설계되었다. R2SDF와 R2SDC 구조를 혼합하여 적용함으로써 메모리 용량을 최소화 하였으며, R2SDC 단일 구조로 구현한 경우에 비해 메모리 크기를 약 $62\%$ 감소시켰다. 또한 TS_CBFP(Two Step Convergent Block Floating Point)를 사용하여 SQNR를 향상시켰으며, 50MHz(a)2.5-V로 동작하는 경우 2048점 FFT/IFFT 연산에 $41-\;{\mu}s$가 소요되었다 Verilog-HDL로 설계된 코어는 $0.25-\;{\mu}m$ CMOS Cell 라이브러리로 합성한 결과 약 68,400개의 게이트와 58,130 비트의 메모리로 구현되었으며, switching activity를 산출하여 전력소모를 측정한 결과 2048점 FFT의 경우 113-mW의 전력을 소모하는 것으로 추정되었다. 설계된 코어를 FPGA에 구현하여 동작시킨 결과 정상 동작을 검증하였으며, 전체 평균 50-dB 이상의 SQNR 성능을 보였다. This paper describes a design of FFT/IFFT Core(FFT256/2k), which is an essential block in terrestrial DMB modem. It has four operation modes including 256/512/1024/2048-point FFT/IFFT in order to support the Eureka-147 transmission modes. The hybrid architecture, which is composed of R2SDF and R2SDC structure, reduces memory by $62\%$ compared to R2SDC structure, and the SQNR performance is improved by TS_CBFP(Two Step Convergent Block Floating Point). Timing simulation results show that it can operate up to 50MHz(a)2.5-V, resulting that a 2048-point FFT/IFFT can be computed in 41-us. The FFT256/2k core designed in Verilog-HDL has about 68,400 gates and 58,130 RAM. The average power consumption estimated using switching activity is about 113-mW, and the total average SQNR of over 50-dB is achieved. The functionality of the core was fully verified by FPGA implementation.

지간 신경종에서 보존적 치료 및 수술적 치료의 임상적 결과

이진우,한승환,서동석,Lee, Jin-Woo,Han, Seung-Hwan,Suh, Dong-Suk 대한족부족관절학회 2006 대한족부족관절학회지 Vol.10 No.1

Purpose: To evaluate the usefulness of ultrasound and MRI in diagnosing Morton's Neuroma, and the effect and significance of stepwise treatment. Materials and Methods: Out of all patients suspected of Morton's neuroma through history taking and physical examination, 77 patients (84 feet, 95 lesions) in whom Morton's neuroma was confirmed by ultrasound or MR imaging study or was clinically suspected with negative imaging studies, and followed up for over 3 months were included. In all cases, history taking and imaging study were done, and by comparison with operative findings of the patients, the sensitivity of ultrasound and MRI was checked. Postoperative evaluation was done using the AOFAS scale. The patient's satisfaction was also examined. Results: Morton's neuroma occurred most frequently at the $3^{rd}$ web space of the foot (56%), followed by the $2^{nd}$ web space (44%). Out of 15 cases suspected of morton's neuroma through ultrasound study, 13 were pathologically positive showing a sensitivity of 85.7%. Out of 16 cases suspected of morton's neuroma through MRI, 14 were pathologically positive showing a sensitivity of 83.3%. There was no significant difference in sensitivity between the two imaging modalities. Conclusion: In diagnosing Morton's neuroma, ultrasound examination had a similar sensitivity with MRI, therefore can be used as a screening study.