정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Overfitting 제거를 위한 규칙 확장

한진철,윤충화 明知大學校 産業技術硏究所 2005 産業技術硏究所論文集 Vol.24 No.-

RPA (Recursive Pattern Averaging) algorithm, which is an instance-based learning method, generates representative patterns from training set, and uses them to classify a test pattern by computing Euclidean distances. RPA is proven to show satisfactory performance, but it has a major disadvantage that it cannot explain the user how the classification result is obtained. This explanation capability is crucial to some domains where expert systems are employed. In order to overcome this disadvantage, we propose a rule-extracting algorithm that produces IF-THEN rules from RPA method, and a pruning algorithm by expanding conditions in IF part of rules in order to improve generalization capability.

향상된 메모리 기반 학습 알고리즘

한진철,김상귀,윤충화 명지대학교 산업기술연구소 2006 産業技術硏究所論文集 Vol.25 No.-

K-NN (k-Nearest Neighbors), which is a well-known memory-based learning algorithm, simply stores entire training patterns in memory, and uses a distance function to classify a test pattern. K-NN is proven to show satisfactory performance, but it is notorious for memory usage and lengthy computation. Various studies have been found in the literature in order to minimize memory usage and computation time, and NGE (Nested Generalized Exemplar) theory is one of them. In this paper, we propose RPA (Recursive Partition Averaging) and IRPA (Incremental RPA) which is an incremental version of RPA. RPA partitions the entire pattern space recursively, and generates representatives from each partition. Also, due to the fact that RPA is prone to produce excessive number of partitions as the number of features in a pattern increases, we present IRPA which reduces the number of representative patterns by processing the training set in an incremental manner. Our proposed methods have been successfully shown to exhibit comparable performance to k-NN with a lot less number of patterns and better result than EACH system which implements the NGE theory.

첫 입원치료 받은 정신분열병 환자들의 삶의 질 추적 연구

한오수,이철,최지욱,홍진표,김창윤 大韓神經精神醫學會 1997 신경정신의학 Vol.36 No.6

울산의대 서울중앙병원 정신과에서 첫 입원 치료를 받고 퇴원하여 2년 혹은 5년이 경과한 정신분열병과 기타 정신병 108명 중 최종 73명(응답을 66%)을 대상으로 Heinrichs등이 고안한 삶의 질 척도(Quality of Life Scale)를 사용하여 현재의 삶의 질을 평가하여 다음과 같은 결과를 얻었다. 첫째, 삶의 질 측면 4가지 측면인 대인관계, 직업적 역할, 정신내적 요소, 및 일상적인 물건 및 행동 모두에서 삶의 질이 전반적으로 저하되어 있음을 관찰할 수 있었다. 대인 관계 영역 중 가족 구성원과의 인적 관계 항목은 다른 항목에 비해 상대적으로 만족도가 높았다. 둘째, 정신분열병군의 삶의 질은 기타 정신병군에 비해 대부분의 삶의 질 항목에서 유의하게 낮은 것으로 나타났다. 셋째, 2년 경과군과 5년 경과군 사이 삶의 질은 유의한 차이를 보이지 않았다. 발병 초기 삶의 질 저하가 상당기간 유지됨을 시사하였다. 넷째. 퇴원 후 삶의 질에 영향을 미치는 변인으로는 첫 입원 치료 기간이 유의한 역상관관계를 보였으며 또한 다변량 회귀 분석에 있어서도 같은 결과를 보였다. 이는 초기 치료에 대한 반응 정도가 부분적으로는 향후 삶의 질을 예측할 수 있음을 시사한다. 기타 첫 입원 당시의 연령, 교육 수준. 사회경제적 수준, 첫 입원하기까지의 이환 기간, 첫 입원 당시 Global Assessment of Functioning 입원 치료시 약물용량 등은 삶의 질과 유의한 상관관계를 보이지 않았다. Objectives : One object of this study is to provide a descriptive level of qua1ity of life(QOL) in a group of the first admired schizophrenic patients through interviews being performed after two or five yeah of fo11ow-up, and comparing them with patients in psychotic disorders other than schizophrenia. Another object is to identify clinical variables on the first admission which correlate to QOL factors, after two or five years of fo11ow up. Methods : A total of 73 subjects of the first admitted patients with schizophrenia(n=57) and psychotic disorders other than schizophrenia(other psychotic disorders group, n= 16) were selected. A Quality of Life Scale(QLS) measuring 21 items of life variables was used. Demographic and psychiatric data were obtained through medical records and psychiatric interviews. Results : Schizophrenia group(n=57) showed moderate decrease(mean 3.7 of 6) in all aspect of quality of life. However, the schizophrenia group displayed a relatively high score in relations with household members(mean=5.2) only among 21 QOL items. Comparison to other psychotic disorders group(n= 16), schizophrenia group showed a significant decrease in almost all aspects of QOL. No significant difference was obtained between the 2 year(n=27) and the 5year(n= 30) group. Duration of the first admission showed a significant correlation with current quality of life in the schizophrenic group. Conclusions : The significantly decreased score of quality of life suggests the need for careful observation and therapeutic concern for the early stage of schizophrenia. The schizophrenic group's relatively high score in relations with household members in this period may provide the importance of rehabilitation to improve their quality of life. Duration of the first admission may be a useful predictor of their subsequent quality of life.

도시 쉼터 노숙자의 정신장애 유병율과 삶의 질

한오수,홍진표,하지혜,이철,김창윤,이동우,박종익 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.5

연구목적 : 외환위기 이후에 급증한 노숙자 문제는 경제적인 상황의 호전에도 불구하고 만성화하는 경향을 보이고 있다. 쉼터의 노숙자를 대상으로 정신질환의 유병율과 삶의 질에 대한 조사를 시행하였다. 방 법 : 2000년 3월에 서울의 대표적인 쉼터에 거주하는 노숙자220명을 대상으로 인구학적 자료에 대한 설문조사를 한 뒤 Structured Clinical for DSM-Ⅳ(SCID-I)을 이용하여 AxisⅠ의 주요 정신질환을 진단하였다. 또 SmithKline Beecham Quality of Life Scale(SBQOL)를 사용하여 삶의 질정도를 평가하였다. 결 과 : DSM-Ⅳ AxisⅠ의 정신질환 중 기분장애, 정신병적 장애, 물질 사용 장애에 대한 진단 평가 결과 상기정신질환의 전체 평생 유병율은 73.6%, 현재 유병율은 59.1%이었다. 알코올 의존과 남용의 평생 유병율은 59.5%로 가장 높았고, 기분장애와 장애가 각각 39.5%, 3.6%이었다. 삶의 질은 노숙의 기간이나 실직 기간과 유의한 관계가 없었고, 자신이 지각한 건강상태, 자살과거력, 우울장애 유무와 통계적으로 유의하게 상관관계가 있었다(p<0.01). 결 론 : 노숙자에서 정신질환 중 알코올 장애의 유병율이 가장 높았으며, 우울장애가 있는 경우에 삶의 질이 저하되는 것으로 나타났다. Objectives : Homeless people surged after financial crisis tend to be chronic despite late economic recovery. So we tried to estimate prevalence of mental illness and quality of life of the homeless population living in shelter. Method : The study subjects were 220 homeless peoples who stayed at a shelter in Seoul around March 2000. Questionnaires on sociodemographic data were administered to the subjects, and then diagnoses of major DSM-Ⅳ Axis I mental disorders were made using Structured Clinical Interview for DSM-Ⅳ Axis I Disorders(SCID). And quality of life(QOL) was evaluated by SmithKline Beecham Quality of Life(SBQOL). Results : The lifetime prevalence of major DSM-Ⅳ mental disorders(mood disorders, psychotic disorder, and substance use disorder) of 220 homeless people was 73.6%, and current prevalence was 59.1%. The lifetime prevalence of alcohol dependence and abuse was highest, 59.5% and those of mood disorder and psychotic disorder were 39.5%, 3.6% respectively. Quality of life was not significantly correlated with duration of homelessness and unemploy-ment but marital status, self perceive health status, suicidal attempt history were significant factors. The quality of life in the people with mood disorders were estimated to be lower than those with any other diseases(p<0.01). Conclusion : Alcoholism was the most prevalent mental disorder in homeless people and mood disorder was negatively related to the quality of life scale.

결핵의 진단법으로서 중합효소 연쇄반응 검사의 가치

서상철,은상진,김한길,송경은,서장수,최성만,이원길,김재식,김중명 慶北大學校 醫科大學 1994 慶北醫大誌 Vol.35 No.1

목적 : 결핵균 동정을 위한 중합효소 연쇄반응을 임상병리검사로서 적용하기 위한 기초 실험으로 분석학적 예민도와 특이도를 알아보고 검토된 조건에 의한 중합효소 연쇄반응을 실제 임상 가검물에 적용하기 위함이다. 재료 및 방법 : Ziehl-Neelsen염색 양성인 객담, 뢰벤스타인-젠센(Loewenstein-Jensen) 배지에서 분리된 결핵균 및 M. tuberculosis H37Rv를 비롯한 항산균 표준균주 11주와 비항산균 10주를 사용하여 2가지 DNA의 분리법, 3set 프라이머, 3종류 중합효소, 2가지 미량 원심시험관 및 Easy-Cycler^R(Ericomp사, 미국)와 수조형으로 검사를 시행하여 DNA 증폭 산물을 비교하였다. 또한 이미 지일-닐슨 염색법에 의한 선별검사에서 음성을 나타낸 객담 53예, 소변 101예, 삼출액 128예, 뇌척수액 54예 등 총 370예의 임상가검물을 대상으로 하여 위에서 검토된 중합효소 연쇄반응 조건으로 검사한 성적과 지일-닐슨 염색법, 배양법 성적과 비교하였다. 결과 : DNA분리방법 2가지와 3가지 중합효소는 분석학적 예민도와 5fg로 나타나 차이를 발견할 수 없었으며, 프라이머 P1, P2쌍은 예민도가 5fg, 프라이머 INS1, INS2쌍과 프라이머 Pt3, Pt6쌍의 예민도는 0.5fg이었다. Easy-Cycler^R가 수조형에 비해 높고, 미량 원심시험관은 Robbins사 제품이 Sarstedt사 제품에 비해 높은 분석학적 예민도를 나타냈다. 프라이머 P1, P2쌍과 프라이머 INS1, INS2와 Pt3, Pt6 2쌍의 프라이머의 특이도에 있어서는 항산균 표준균주 중 M. tuberculosis H37Rv, M. tuberculosis ATCC 27294, M. bovis ATCC 29312의 3주에서 특이 증폭 띠를 관찰할 수 있었다. 그러나 비결핵성 항산균 8주에는 특이 증폭 띠를 나타내지 않았다. 또 비항산균 10주에도 특이 증폭 띠가 관찰되지 않았다. 따라서 Robbins사의 미량 원심시험관과 proteinase-K법에 의한 DNA분리방법에 Easy-Cycler^R를 사용하여 프라이머 INS1, INS2쌍으로 일차 중합효소 연쇄반응을 시행한 후 프라이머 Pt3, Pt6쌍으로 이차중합효소 연쇄반응을 시행하는 방법을 370예의 임상가검물에 시행하였고 지일-닐슨 염색법과 결핵균배양검사도 동시에 시행한 결과 중합효소 연쇄반응 양성은 106예(28.6%), 배양 양성은 27예(7.3%) 및 염색 양성은 18예(4.9%)였으며, 결핵환자는 141명(38.1%)였다. 370예의 임상 가검물로 시행한 중합효소 연쇄반응의 진단학적 예민도와 특이도, 양성결과 예측치 및 음성결과 예측치는 68.8%, 96.1%, 91.5% 및 83.3%로 각각 나타났다. 결론 : 결핵균 동정을 위한 중합효소 연쇄반응은 배양검사에 비해 신속하며, 분석학적인 예민도와 특이도가 뛰어나므로 결핵 진단을 위한 임상병리검사로서 유용하다고 사료됨. In this study, We investigated the optimal conditions of polymerase chain reaction(PCR) assay for the rapid identification of Mycobacterium tuberculosis in clinical specimens as routine laboratory test. So we have compared two DNA isolation methods, 3 polymerases, 2 set of primer, 2 kinds of thermocycler and 2 microtubes. We evaluated two DNA isolation methods, bead-beating method and proteinase-K method, the latter was more sensitive than the former. In comparision of two sets of primers, P1 and P2 primers detecting 123-base pair fragment of IS6110 made from Biosnthesis(U. S. A.) and INS1 and INS2 primers detecting 245-base pair fragment of IS986 showed equally sensitive results ie. 5fg. Specificity of primers were tested and INS1 and INS2 primers gave 245-base pair product from M. tuberculosis H37Rv, M. tuberculosis ATCC 27294 and Mycobacterium bovis ATCC 29312 but not from 8 nontuberculous mycobacterial strains such as M. kansasii ATCC 12478, M. terrae ATCC 15755, M. intracellurae ATCC 13950, M. avium ATCC 25281, M. gordonae ATCC 14470, M. fortuitum ATCC 6841, M. smegmatis ATCC 19420, M. scrofulaceum ATCC 19981. Coagulase-positive staphylococcus, coagulase-negative staphylococcus, streptococcus, Esccherichia coli, Serra-tia marcescens, Klebsiella pneumoniae, Enlerobacter aerogenes, Enterobacter cloacae, Acinetobacter calcoaceticus, Pseudomonas aerugonosa showed no 245-base pair amplification product. PCR by the P1 and P2 primers showed 123-base pair amplification product from M. tuberculosis H37Rv, M. tuberculosis ATCC 27294 and Mycobacterium bovis ATCC 29312 but not from 8 nontuberculous mycobacterial strains such as M. kansasii ATCC 12478, M. terrae ATCC 15755, M. intracellularae ATCC 13950, M. avium ATCC 25281, M. gordonae ATCC 14470, M. fortuitum ATCC 6841, M. smegmatis ATCC 19420, M. scrofulaceum ATCC 19981. Coagulase-postive staphylococcus, coagulase-negative staphylococcus, streptococcus, Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Enlerobacter aerogenes, Enterobacter cloacae, Acinelobacler calcoaceticus, Pseudomonas aeruginosa showed no 123-base pair amplification product. In comparision of polymerase, Taq DNA polymerase^R(Promega Co., U. S. A.) was more cost effective than Ampli Tag^R(Perkin-Elmer Cetus, U. S. A.), but these two were equally sensitive and specific in the detection of M. tuberculosis-specific DNA. Tac polymerase (Korea'Biotech, Korea) showed many nonspecific bands. In comparision of thermocycler, Easy-Cycler^R(Ericomp, U. S. A.) was more sensitive than water-bath type and in that of microtubes Robbin's were more sensitive than Sarstedt's PCR results were compared with results of culture for M. tuberculosis and Ziehl-Neelsen stain in 370 clinical specimens that were negative by initial Ziehl-Neelsen stain. There were 27 specimens(7.3%) that were positive for M. tuberculosis by culture, 18(4.9%) specimens that were positive by Ziehl-Neelsen stain, and 106 specimens(28.6%) that were positive for PCR and 141 cases that were positive for tuberculosis. Overall sensitivity, specificity, positive predictive value and negative predictive value were 68.8, 96.1, 91.5 and 83.3% respectively, for PCR; 19.1, 100, 100, and 66.8%, respectively for culture; and 12.8, 100, 100, and 59.0% respectively for Ziehl-Neelsen stain.

수지 원위부 절단의 재접합술

차진한,박명철 大韓成形外科學會 1993 Archives of Plastic Surgery Vol.20 No.1

Replantation of the upper extremity has been developed over 30 years from a laboratory experimental model to a common techique applicable to acute and reconstructive hand surgeries. Today, successful replantation of fingers proximal to the middle phalanx is common. yet salvage of amputated fingers, distal to the DIP joint is still a challanging problem. Technical expertise in microvascular surgery may allow the true replantation of parts amputed within the distal interphalangeal joint. The functional and cosmetic success of these replantations is excellent. The authors report replantation cases, distal to the distal interphalangeal joint of fingers and retrospective analysis of 20 cases which were treated at Min Joong hospital, Collge of Medicine, Kon Kuk university, from October 1988 to February 1992 The results were as follows : 1. The survival rate of amputated digits distal to the DIP joint was 85% 2. Important factors for the successful replantation were the type of injury and the degree of crushing. 3. Replanted digits were improved in esthetical and functional aspects 4. If possible, the authors tried the venous anastomosis in 13 cases among the total 20 of cases.

습지의 간척에 따른 환경·생태적 기능가치에 대한 비교

조한진,서종환,이철승,안철우,김수생 동아대학교 환경문제연구소 2003 硏究報告 Vol.25 No.2

This study on the environmental-ecological functional value of reclaiming from wet land for a standard of refutation on development and preservation. Korean wet land gives us seafood, social and cultural service of human and livelihood to be self-supporting the foods, supports etc, but at the same time wet land has ecologically sensitive and irreversible features. So we need to have maintainable management strategies considered the safe minimum standards. But Korean wet land has been developed 30% since 1980, and other wet land remain undeveloped has been pressured to develop. Pre-studies have been careless about the negative functions about water quality of paddy. But by the results of this study, we can know that total economic values are negative effects. The negative effects of environment pollution are bigger than the affirmative. And we need to compare and analyze the economic value of wet land and reclaimed land in order to produce more exact cost-benefit analysis on the preservation and development. But when we consider economic value of the liquid-quality purification between wet land and reclaimed land, the value of wet land is greater than reclaimed land.

수부손상에 대한 임상적 고찰

박명철,최은정,차진한 大韓成形外科學會 1993 Archives of Plastic Surgery Vol.20 No.1

The hand has much more delicate functions to be performed and its structural characters shoud be fully understood to mannage them properly. In care of hand injuries, is is essential for prevention of deformities and residual sequelas after injury, exact preoperative diagnosis, proper treatment, and intensive postoperatvie care. A statistical analysis was carried out on 464 patients of hand injuries, who were treated at the Department of Plastic, and Reconstructive Surgery, Konkuk University hospital, from October, 1988 to December, 1991. The followings are the results of our analysis, 1. The peak incidence rate was in the age group of 20-29 yerars(40.9%) and most of all were male in 87.4% 2. The glass injury was the most common cause of injuries in 30.4%. 3. Most of the patients were able to get the chance of early medical card by arriveing hospital within six hours in 87.7%. 4. There were no significant difference rate of all seasons. 5. The most frequency of admission duration was 1 week(53.0%) and OPD treatment usually lost for 1-2months(61.2%) 6. Monodigit injury(47.4%) was most frequenly involved, of mondigit injury was index finger(31.3%) 7. The type of injury was mainly crushing(40.3%), involving multiple structures. 8. 26.5% of hand injuries were treated with debridement and multiple combined operation. 9. Various complication of hand injuries were observed in 5.8% and the most commin complication was infection in 10 cases(37.1%). 10. Results of recovery was more excellent in a single injury than combined injury.

세가지 형상의 부유식 방파제 특성에 대한 비교연구

조원철,한덕만,양우석,이진원 중앙대학교 기술과학연구소 2000 기술과학연구소 논문집 Vol.30 No.-

본 연구는 2차원 유한요소모델을 이용한 부유식 방파제의 파랑감쇠특성에 대한 이론적 연구이다. 유체의 운동은 선형적이고, 2차원적인 포텐셜 흐름으로 가정하고 수치해석을 수행하였으며, 2차원 유한요소해석과 무한요소해석을 채택하여 부유식 방파제 영역에 적용하였다. 따라서 2개의 영역에 있어 방파제 근처 영역에서는 유한요소해석을 적용하였으며, 그 외의 영역에서는 무한요소해석을 사용하였다. 방파제의 형식은 직사각형, 원형, 사다리꼴의 세가지 형상으로 하였으며, 그 결과를 기존의 실험결과와 비교하였다. A theoretical investigation on the wave-attenuation characteristics of floating breakwaters are presented. The fluid motion is idealized as linearized, two dimensional potential flow. A two-dimensional finite element model is adopted to study the performance of floating breakwaters. The near field region surrounding the solid body is modeld using conventional finite elements, however, the far field region is represented appling the infinite elements. Numerical analysis is carried out for floating breakwaters with three different cross-sectional shapes, rectangular, circular and trapezoidal shapes, respectively. Comparison with hydraulic experimental results measured in the past is carried out to prove the validity of the numerical results.