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.

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.

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.

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.

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.

대역폭의 제한을 받는 TCP over ATM의 특성

이진우,박기태,김진태,김형래,박인갑,Lee, Jin-Woo,Park, Ki-Tae,Kim, Jin-Tae,Kim, Hyung-Lae,Park, In-Kap 한국전기전자학회 1997 전기전자학회논문지 Vol.1 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, nowdays. 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 with limited bandwidth in a broadband environment. As multiple VBR sources occupies most of the available bandwidth, there has been a starvation effect, so TCP sources couldn't get the chance of transmitting data. Also, throughput is proportional to the amount of buffer.

연골하 낭종을 동반한 거골의 골연골 병변의 관절경적 치료 후 임상적 결과 및 방사선학적 변화

이진우,박관규,한수봉,강응식,Lee, Jin-Woo,Park, Kwan-Kyu,Kim, Sung-Jae,Hahn, Soo-Bong,Kang, Eung-Shick 대한족부족관절학회 2003 대한족부족관절학회지 Vol.7 No.1

Purpose: The purpose of this study is to review clinical and radiologic changes after arthroscopic operation without bone graft for osteochondral lesion with subchondral cyst on the talus. And we compared the results with those without cyst. Radiologic changes were also observed. Materials and Methods: Arthroscopic microfrature or abrasion arthroplasty was performed on 10 caeses of osteochondral lesions with subchondral cyst and 20 cases without cysts. Preoperative and postoperative symptoms were evaluated by Ankle-Hind foot scale of AOFAS and the score of two groups were compared(t-Test : Paired Two Test for Means). Radiologic evaluation was performed after operation on patients with osteochondral lesion with cyst. Results: On patients of osteochondral lesion with subchondral cyst on talus, there was clinical improvement compared to the preoperative status and compared to patients without cysts(P=0.01) after arthroscopic operation. We could get increase of density and decrease of size of cystic lesion on plain film with time passage. Conclusion: We report 10 cases with osteochondral lesion with subchondral cyst on talus which resulted in clinical and radiological improvement after arthroscopic microfracture or abrasion arthroplasty without bone graft.

국방 R&D 투자 및 정부, 민간 R&D 투자와 국민소득간의 상호 인과관계 분석

이진우,권오성,Lee, Jin-Woo,Kwon, O-Sung 한국국방경영분석학회 2008 한국국방경영분석학회지 Vol.34 No.1

R&D 투자와 경제성장간의 관계에 대한 많은 기존 논의들은 R&D 투자가 경제성장에 대해 강한 양(+)의 관계가 존재함을 제시하고 있다. 그러나 투자와 성장사이의 강한 결합관계가 반드시 일방적 인과관계를 의미하는 것은 아니기 때문에 인과관계의 방향에 대한 보다 심층적인 연구가 필요하다. 특히 급변하는 안보환경 속에서 국방 R&D 투자가 증대되고 있음을 고려해 볼 때 국방 R&D 투자와 타 부문 R&D 투자 및 경제성장과의 결합관계에 대한 논의에 앞서 각 변수들 간의 인과관계에 대한 연구가 선행되어야 하나, 현재까지 국방 R&D 투자와 타 부문 간의 인과관계를 연구한 실적이 전무한 실정이다. 따라서 국방 R&D 투자와 다른 변수들과의 인과관계 분석을 통하여 국방 R&D 투자정책에 관한 정책적 시사점을 제시하였다는데 본 논문의 의미를 두고자 한다. The purpose of this paper is to find the desirable R&D policies in defense area by analyzing causality between GDP and R&D investments in government, private, defense sectors. We have five variables which are composed of GDP, total R&D investment, R&D investments in government, private and defense sectors to figure out the causality between R&D investment in defense sector and other components. In the course of analysis on causality, we took the unit root test of variables to prevent spurious regression. Also we need to take cointegration test about non-stationary variables before the causality test. According to these test results, we took the causality test using ECM(Error Correction Model) for the models which have cointegrating relations. And we took ordinary Granger causality test for model which doesn't have a long-run stationary relationship. As a result of the causality test, it was shown that there exists the long-nu causality to GDP and R&D investments in government and private sectors from other variables. However, there doesn't exist the causality to defense R&D investment from other variables. We found that there doesn't exist the causality between R&D investments in defense and private sectors, and that they are independent.

무지 외반증을 동반한 중족골통에 대한 Weil씨 절골술

이진우,권세광,한수봉,강응식,Lee, Jin-Woo,Kwon, Sae-Kwang,Hahn, Soo-Bong,Kang, Eung-Shick 대한족부족관절학회 2003 대한족부족관절학회지 Vol.7 No.1

Introduction: Painful plantar callosities under the second and third metatarsal heads are not uncommonly associated with hallux valgus and there have been controversies concerning its treatment modalities. We performed the Weil osteotomy in patients with painful callosities under the second and third metatarsal head associated with hallux valgus, and evaluated the outcome clinically & radiologically. Materials and Methods: From November 2000 through November 2001, out of 51 patients diagnosed with hallux valgus, the Weil osteotomy was performed in 5 women associated with painful callosities under the second and third metatarsal heads. The mean age was 53.4 years (range, 31-66) with a minimum follow-up period of 12 months(range, 12-16). Results: The mean AOFAS lessor metatarso-phalangeal-interphalngeal Scale(LMIS) improved from 61.2 points preoperatively to 88.8 points postopertively. Mean decreases in length of the second and third metatarsal after surgery were 3.2mm and 3mm. Conclusion: We experienced improvement of metatarsalgia in 80% of patients by Weil osteotomy and all patients were symptom-free at last follow-up, suggesting that the Weil osteotomy is an effective procedure in treating painful plantar callosities under the second and third metatarsal heads associated with hallux valgus.

동수압 모형을 이용한 트렌치 수로에서의 흐름 해석

이진우,조용식,Lee. Jin Woo,Cho. Yong-Sik 한국방재학회 2012 한국방재학회 학술발표대회논문집 Vol.2012 No.1

본 연구에서는 동수압 모형을 이용하여 트렌치 수로에서 발생하는 흐름해석을 실시하였다. 기존의 정수압 모형은 수식이 간단하고 수치기법의 적용이 상대적으로 쉬운 반면 수심이 파의 길이에 비해 상대적으로 작은 경우에만 적용이 가능하므로 수심이 커지게되면 비 물리적인 결과를 계산하게 된다. 따라서 흐름방향으로 밀도차가 큰 경우나 수중구조물로 인하여 바닥경사가 변하는 경우에는 동수압이 고려되어야 한다. 본 연구에서는 압력항을 정수압과 동수압으로 분리하고 일반 좌표계를 사용함으로써 자유수면이 매시간단계마다 변화하는 계산격자를 구성해야하는 문제점을 보완할 수 있었다. 자유수면과 동수압을 고려하기 위해서 계산단계를 3단계(정수압 계산단계, 동수압 보정단계, 자유수면 보정단계)로 나누어 해석하였고 트렌치 수로에서의 수리실험 결과 (van Rijn, 1982)와 비교를 통해 수치모형을 검증하였다.