매입형 영구자석 동기전동기의 인덕턴스 측정법 비교 분석

김승주(Seung-Joo Kim),김철진(Cherl-Jin Kim),이주(Ju Lee) 대한전기학회 2009 전기학회논문지 Vol.58 No.5

The performance analysis and robust control of the interior permanent magnet synchronous motor (IPMSM) greatly depend on accurate value of its parameters. To achieve the high performance of torque control, it is necessary to consider exact inductance values because the inductances are nonlinear parameters of operating the IPMSM. Therefore many different methods have been performed for analysis of the methodology for the exact measurement of synchronous inductances. None of them is considered standard, and accuracy levels of all these methods are also not consistent. Among these experimental methods, the DC current decay test and the vector current control test are ideal for a laboratory environment. In this paper, these two test methods are compared by applying inductances to the IPMSM. The paper analyzes the measured inductances of the two methods and their differences with inductances obtained from the finite element method(FEM).

단상 유도형 동기 전동기의 성능향상을 위한 고찰

이진헌(Jin-hun Lee),김승주(Seung-joo Kim),최승길(Seung-kil Choi),이주(Ju Lee) 대한전기학회 2007 대한전기학회 학술대회 논문집 Vol.2007 No.10

In previous structure of single phase LSPM, there is large torque ripple that makes a noise and a vibration by a distortion of flux distribution in air gap. By this reason, the single phase LSPM is not accepted home applications. So, in this paper, we propose new structure of single phase LSPM(Line Start Permanent magnet Motor). The proposed model is reduced a torque ripple about a half than previous model.

위암에서 종양 크기의 임상적 의의

김학진 ( Hak Jin Kim ),장유진 ( You Jin Jang ),김종한 ( Jong Han Kim ),박성수 ( Sung Soo Park ),박성흠 ( Sung Heum Park ),김승주 ( Seung Joo Kim ),목영재 ( Young Jae Mok ),김종석 ( Jong Suk Kim ),박중민 ( Jung Min Park ),양경숙 ( 대한임상종양학회 2010 Korean Journal of Clinical Oncology Vol.6 No.1

배경 및 목적 : 현재까지 위암의 예후를 결정하는 가장 중요한 인자는 종양의 침윤 깊이와 림프절 전이여부 이지만 이밖에 종양크기가 예후를 결정한다는 보고가 있다. 또한 최근 조기위암에서 내시경적 절제술의 빈도가 증가하고 있는데, 이에 대한 적응 증을 결정하는데 종양 크기가 중요한 요소가 되고 있다. 이에 저자들은 위암에서 종양 크기의 예후적 중요성 및 림프절 전이와의 관련성에 대하여 알아보고자 하였다. 대상 및 방법 : 1992년부터 2002년까지 고려대학교 병원에서 근치절제술을 시행 받은 위암 1기에서 3기까지의 928명의 환자를 대상으로 후향적으로 연구하였다. 다변량 위험도 비교분석의 결과로 예후에 영향을 미치는 종양 크기의 기준 값을 구하였고 이를 기준으로 두 군으로 나누어 임상병리학적 인자와의 관련성 및 예후적 의의에 대하여 알아보았다. 또한 림프절 전이 여부에 영향을 미치는 종양 크기의 기준 값을 ROC curve 를 사용하여 전체 및 각 종양 병기(pT)에 대하여 알아보았다. 결과 : 다 변량 위험도 분석상 예후에 영향을 미치는 종양 크기의 기준 값은 7 cm 이었으며 이를 기준으로 두 군으로 나누어 임상 병리학적 특성을 비교한 결과 종양의 위치, 침윤 깊이, 림프절 전이 및 세포 분화도 에서 유의한 차이를 보였다. 다 변량 생존 분석 결과 나이, 침윤 깊이, 종양 크기 및 림프절 전이가 독립적으로 유의한 예후인자였다. 종양크기와 림프절 전이와의 관련성에서는 전체 환자군 및 종양 병기 1기(pT1), 3기(pT3)에서 유의하였으며, 이를 결정하는 기준 값은 전체 환자군 3.3 cm, 종양 병기 1기 1.5 cm, 종양 병기 3기 6 cm이었다. 결론 : 위암에서 종양 크기는 의미 있는 예후 인자이며 림프절 전이 여부를 결정하는데 중요한 인자이다. 따라서 조기위암에서 내시경적 절제술 시행 여부 및 진행성 위암에서 향후 치료 방침을 결정하는데 있어서 참고 자료가 될 수 있을 것이다. Purpose: The objectives of this study were to investigate the impact of the tumor size on survival of gastric cancer patients who underwent curative resection and to evaluate relationships between tumor size and lymph node metastasis Materials and Methods: We retrospectively studied 928 gastric cancer patients who underwent curative resection at Korea University Medical Center from 1992 to 2002. The cut-off value of tumor size was decied as the smallest value that showed significantly survival difference by COX proportional hazard model. The clinicopathological factors associated with tumor size were analyzed by using univatiate and multivariate analyses. And ROC curves were applied to measure cut-off value of tumor size that impact on lymph node metastasis. Results: In COX proportional hazard model , the cut-off value of tumor size was 7cm that impact on prognosis. The tumor location, depth of invasion, lymph node metastasis, and cell differenciation were significantly different according to the tumor size. The Age, depth of invasion, tumor size and lymph node metastasis were independent prognostic factors by using multivariate analyses. In Releavance between the tumor size and lymph node metastasis, there were significant difference stage I, III, and whole patients group. And the each cut-off values were 1.5cm, 6cm, and 3.3cm Conclusion: Tumor size was significant prognostic factor and important predictive value for lymph node metastasis in gastric cancer. So tumor size will useful parameter to perform EMR in early gastric cancer or to plan further management of advanced gastric cancer.

분산 데이터베이스 환경에 적합한 Challenge-Response 기반의 안전한 RFID 인증 프로토콜

이근우,오동규,곽진,오수현,김승주,원동호,Rhee Keun-Woo,Oh Dong-Kyu,Kwak Jin,Oh Soo-Hyun,Kim Seung-Joo,Won Dong-Ho 한국정보처리학회 2005 정보처리학회논문지 C : 정보통신,정보보안 Vol.12 No.3

Recently, RFID system is a main technology to realize ubiquitous computing environments, but the feature of the RFID system may bring about various privacy problem. So, many kinds of protocols To resolve this problem are researched. In this paper, we analyse the privacy problem of the previous methods and propose more secure and effective authentication protocol to protect user's privacy. Then we prove that the proposed protocol is secure and effective as we compare the proposed protocol with previous methods. The proposed protocol is based on Challenge-Response using one-way hash function and random number. The proposed protocol is secure against replay attack, spoofing attack and so on. In addition, the proposed protocol is proper for distributed database environment. 최근 유비쿼터스 환경의 실현을 위한 핵심기술로서 RFR 시스템에 대한 연구가 활발히 진행되고 있다. 그러나 RFID 시스템이 가지고 있는 특성으로 인하여 사용자 프라이버시 침해 문제가 대두되고 있으며, 이를 해결하기 위한 프로토콜들이 개발되었다. 본 논문에서는 기존의 기법들이 가지고 있는 프라이버시 침해 문제를 분석하고 보다 안전하고 효율적으로 사용자의 프라이버시를 보호할 수 있는 인증 프로토콜을 제안한다. 또한 기존의 RFID 인증 기법들과 비교하여 제안하는 프로토콜이 안전하고 효율적임을 증명한다. 제안하는 프로토콜은 일방향 해쉬 함수와 난수를 이용한 Challenge-Response 방식에 기반하고 있으므로 공격자의 재전송 공격 및 스푸핑 공격 등에 안전하고, 분산 데이터베이스 환경에 적합하다.

배리어 길이에 따른 매입형 영구자석 동기전동기의 Ld, Lq 파라미터 특성에 관한 연구

장익상(Ik-Sang Jang),김승주(Seung-Joo Kim),진창성(Chang-Sung Jin),김기찬(Ki-Chan Kim),이주(Ju Lee) 대한전기학회 2009 전기학회논문지 Vol.58 No.3

Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux ψa and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, the influence of barrier width on the ψa and Ld, Lq is calculated by FEM analysis. Predictions are validated by comparison the average torques, using Maxwell Stress Tensor method.

LC 발전 고진법을 이용한 매입형 영구자석 동기 전동기의 파라미터 계산

장익상(Ik-Sang Jang),김승주(Jin Seung Joo),진창성(Chang Sung Jin),이주(Ju Lee) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.4

Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux Ψ<SUB>a</SUB> and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, L<SUB>d</SUB>, L<SUB>q</SUB> is calculated by LC resonance method with FEM. The results are validated by comparison the L<SUB>d</SUB>, L<SUB>q</SUB> calculated by another method.

절제 불가능한 4기 위암에서 예방적 위 공장 우회술의 의의

김환수,김종석,김종한,목영재,박성수,박성흠,장유진,김승주,Kim, Hwan-Soo,Kim, Chong-Suk,Kim, Jong-Han,Mok, Young-Jae,Park, Sung-Soo,Park, Seong-Heum,Jang, You-Jin,Kim, Seung-Joo 대한위암학회 2009 대한위암학회지 Vol.9 No.4

목적: 진행성 위암 중 수술 소견에서 복강 내 원격전이가 존재하거나 주위 장기에 침윤이 심하여 절제가 불가능한 경우에 위 배출구 폐색을 동반하지 않더라도 예방적 위공장 우회술을 시행하는 경우가 있어, 단순 개복술 시행과 비교하여 그 의의를 알고자 하였다. 대상 및 방법: 1984년부터 2007년까지 고려대학교 의료원에서 수술을 시행 받은 진행성 위암 환자 중 위 배출구 폐색이 없고 절제 불가능한 4기 위암 환자 167예를 대상으로, 후향적 방법을 이용하여 임상병리학적 특성 및 치료성적, 그리고 예후 인자 분석을 시행하였다. 결과: 위 공장 우회술을 시행과 단순 개복술 시행을 비교한 결과, 나이, 성별, 간 전이 여부, 술 후 재원일, 재입원 횟수에서는 유의한 차이를 없었지만, 병소의 위치(P$\leq$0.014), 복막 파종(P=0.001)에서는 유의한 차이를 보였다. 예후 인자 분석에서는 위 공장 우회술을 시행한 군의 생존기간이 1~35.7개월(6.3개월), 시행하지 않은 군이 1~33.4개월(median 4.3개월)로 유의한 차이가 있었으며(P=0.031), 복막전이가 있는 경우 1~31.0개월(median 3.4개월), 없는 경우 1~33.3개월(median 5.8개월)로 유의한 차이를 보였다(P<0.001). 다변량 분석을 통한 독립적 예후 인자로는 복막 전이 여부만이 의미가 있었다(P=0.002). 결론: 절제 불가능한 4기 위암 환자에서 폐색 증상이 없는 경우, 예방적 위 공장 우회술은 생존기간의 연장에서 큰 의의를 가지지 못하는 것으로 생각한다. Purpose: The aim of this study was to evaluate the significance of palliative gastrojejunostomy for treating patients with unresectable stage IV gastric cancer, and as compared with laparotomy for treating patients with incurable gastric cancer. Materials and Methods: We retrospectively studied 167 patients who could not undergo resection without obstruction at Korea University Hospital from 1984 to 2007. They were classified into two groups, one that underwent palliative gastrojejnostomy (the bypass group, n=62) and one that underwent explo-laparotomy (the O&C group, n=105), and the clinical data and operative outcomes were compared according to the groups. Results: For the clinical characteristics, there were no differences of age, gender and liver metastasis between the bypass group and the explo-laparotomy group, but there was a significant different for the presence of peritoneal metastasis (P=0.001). There was no difference between two groups for the postoperative mortality and morbidity. For the postoperative outcomes, the duration of the hospital stay (29.25 vs 16.67) and the frequency of re-admission were not different, but the median overall survival (4.3 months vs. 3.4 months, respectively) was significantly different. By multivariate analysis, the presence of peritoneal metastasis was identified as the independent prognostic factor for incurable gastric cancer. Conclusion: A prophylactic bypass procedure is not effective for improving the quality of life and prolonging the life expectancy of unresectable stage IV gastric cancer patients without obstruction.

다발성 조기위암의 임상적 고찰

박성수,류근원,송태진,목영재,김종석,김승주,Park Sung Soo,Ryu Keun Won,Song Tae Jin,Mok Young Jae,Kim Chong Suk,kim Seung Joo 대한위암학회 2001 대한위암학회지 Vol.1 No.3

Purpose: Multiple early gastric cancers were found in $6.9\∼11.7\%$ of patients with early gastric cancer. The goal of this study was to clarify the clinicopathologic features of and to investigate treatment strategy for multiple early gastric cancer. Materials and Methods: Of 967 patients with an gastric adenocarcinoma who were treated by surgical resection during the period of $1993\∼1998$ at the Department of Surgery, Korea University College of Medicine, 267 patients had early gastric cancer. A retrospective analysis of the clinicopathologic differences between the main and the accessory lesions in multiple early gastric cancer was carried out. A comparative analysis was also conducted between solitary early gastric cancer and multiple early gastric cancer. Results: Of 267 patients with early gastric cancer, multiple early gastric cancers were found in 12 patients ($4.5\%$), including 10 men and 2 women. Eleven patients with multiple early gastric cancer had one accessory lesion and 1 patient had 2 accessory lesions. Of the 13 accessory lesions, 7 ($53.8\%$) were located in the same region as the main lesion. The most frequent combination of macroscopic types for the main lesion and the accessory lesion were depressed and depressed types (6 cases, $46.1\%$). The most frequent histologic type of main lesion was a well differentiated adenocarcinoma in 7 ($58.3\%$) of the 12 cases; the accessory lesion was also well differentiated in 4 of those 7 cases. Of the 13 accessory lesions, 4 ($30.8\%$) had been overlooked preoperatively; most of them were located in the lower third of the stomach and were IIb or IIc type and measured less than 1 cm in diameter. Lymph node metastasis was detected in 1 patient ($8.3\%$). The clinicopathologic features of multiple early gastric cancer were not different from those of solitary early gastric cancer. Conclusion: In multiple early gastric cancer, the main and the accessory lesions showed similar differentiation, and lymph node metastasis was less frequent than in solitary early gastric cancer. Therefore, limited procedures, including endoscopic mucosal resection, may be indicated if each lesion of the multiple early gastric cancer fits the criteria for treatment strategy.

조기 위암에서 림프절 전이와 관련된 인자에 대한 분석

김동희(Dong-Hee Kim),송태진(Tae-Jin Song),김승주(Seung-Joo Kim),김종석(Chung-Suk Kim),구범환(Bum-Hwan Koo) 대한외과학회 2000 Annals of Surgical Treatment and Research(ASRT) Vol.58 No.3

위암 환자에서의 다발성 원발성 악성종양

류동도,엄준원,손길수,조민영,송태진,김종석,목영재,김승주,Ryu Dong Do,Um Jun Won,Son Gil Soo,Cho Min young,Song Tae Jin,Kim Chong Suk,Mok Young Jae,Kim Seung Joo 대한위암학회 2003 대한위암학회지 Vol.3 No.3

Purpose: Because of an improving gastric cancer detection program and treatment methods, we can expect improved survival of patients with gastric cancer. Given the longer survival times, the chance of an occurrence of multiple primary malignant tumors other than stomach is increased in the same patients. The purpose of this study is to analyze the clinical characteristrics and the survival of patients with gastric cancer and other malignancies. Materials and Methods: A retrospective study of 3669 patients with gastric cancer observed at our department between January 1994 to December 2002 was conducted. Associated tumors were diagnosed using the Warren and Gates criteria, and included tumors that were not considered to be a metastasis, invasion, or recurrence of the gastric cancer. Results: Of all 3669 patients, $2.07\%$ (n=76) had primary tumors other than gastric cancer, $63\%$ of which were synchronous (n=48) and $37\%$ metachronous (n=28). The mean age of the study group was 64.9 (65.5 in males, 61.8 in females), and the male-to-female ratio was 4.8 : 1. The most common cancer associated with gastric cancer was a hepatocellular carcinoma ($23.7\%$), followed by colorectal cancer ($17.1\%$), esophageal cancer ($10.5\%$), breast cancer ($6.6\%$). Of the 45 patients who had undergone a resection, 14 were in stage I, 12 in stage II, 13 in stage III, and 6 in stage IV. No statistically significant differences were found between the synchronous and the metachronous groups with regard to age, sex ratio, differentiation, and stage. The 5-year survival rates of the metachronous and the resected patients were significantly higher than those of the synchronous and the non resected patients, respectively. Conclusion: Due to increasing length of the follow-up period for patients with gastric cancer, another malignancy may develop in other organs. Therefore, physicians should pay attention to detect other cancers early in these patients, and a surgical resection is recommended as the treatment of choice in the management of multiple primary cancer associated with gastric cancer.