RawPEACH: Multiband CSMA/CA-Based Cognitive Radio Networks

정조운,성영철,Dan Keun Sung 한국통신학회 2009 Journal of communications and networks Vol.11 No.2

A new medium access control (MAC) scheme embedding physical channels into multiband carrier sense multiple access/ collision avoidance (CSMA/CA) networks is proposed to provide strict quality of service (QoS) guarantee to high priority users. In the proposed scheme, two priority classes of users, primary and secondary users, are supported. For primary users physical channels are provided to ensure strict QoS, whereas secondary users are provided with best-effort service using CSMA/CA modified for multiband operation. The performance of the proposed MAC scheme is investigated using a new multiband CSMA/CA Markov chain model capturing the primary user activity and the operation of secondary users in multiple bands. The throughput of secondary users is obtained as a function of the primary user activity and other CSMA/CA parameters. It is shown that the new MAC scheme yields larger throughput than the conventional single-band CSMA/CA when both schemes use the same bandwidth.

회장 통로와 회장 정위성 방광대치술 후 신기능의 변화

정조운,손동완,조용현 대한비뇨의학회 2006 Investigative and Clinical Urology Vol.47 No.10

A Non-Cooperative Game on Distributed Dynamic Channel Selection for Multichannel Cognitive Radio Networks

Jo Woon Chong(정조운),Hyundong Shin(신현동) 한국통신학회 2009 한국통신학회 학술대회논문집 Vol.2009 No.11

발기 시 음경통증과 만곡을 동반한 원발성 음경 해면상 혈관종

손동완,정조운,김성대,김두배,김현우,조용현,김세웅 대한남성과학회 2008 The World Journal of Men's Health Vol.26 No.1

Hemangiomas result from proliferation of immature capillary vessels. This disorder in the genitourinary tract is a rare lesion. We experienced one case of a 31 years old man suffered from cavernous hemangioma of the penis shaft with painful erection. He was treated successfully with surgical excision. Herein, we report our experience and a critical review of the literature.

UTRAN Iub 인터페이스에서 QoS 기반의 AAL2/ATM 다중화 전송방안

정창용,정조운,황호영,성단근,정수성,방만원 한국통신학회 2003 韓國通信學會論文誌 Vol.28 No.6

UTRAN Iub 인터폐이스에서 QoS 기반의 AAL2/ATM 다중화 전송방안

정창용,정조운,황호영,성단근,정수성,방만원 한국통신학회 2003 韓國通信學會論文誌 Vol.28 No.6A

Recently, mobile communication systems have supported various services including internet from voice centric service as they evolve toward 3G. To accommodate the increasing number of users, an AAL2 multiplexing scheme is introduced in the UTRAN tub interface for link efficiency. However, limited radio resources and different requirements of various services make it difficult to guarantee the QoS requirements at radio access networks. The conventional AAL2/ATM multiplexing systems focused on the multiplexing efficiency of voice anddata services and QoS issues of real time and non real time services. In this paper, we classfy various services according to QoS requirements and propose AAL2/ATM multiplexing schemes using statistical multiplexing and scheduling with a rather simple structure to guarantee the given requirements. Simulation results show that the proposed schemes perform better than the conventional schemes to guarantee QoS requirements of various services. 최근에 이동통신 시스템이 3세대로 진화하면서 음성 위주의 서비스에서 점차 인터넷 서비스 같은 여러 다양한 서비스들을 지원하게 되었다. 그리고 급증하는 사용자들을 수용하기 위해 무선 가입자망의 Iub 인터페이스에서AAL2 다중화 기술을 도입하여 한정된 링크의 효율을 높이고 있다. 그러나 무선 자원의 부족과 지원되는 다양한 서비스들의 요구조건이 다르기 때문에 무선 가입자망에서는 제대로 각 서비스 별로 QoS를 만족시켜 주지 못하고있다. 기존의 AAL2/ATM의 다중화 시스템에서는 음성과 데이터의 다중화 효과와 실시간성, 비실시간성 서비스에 대해 QoS를 분석해 왔다. 본 논문에서는 여러 다양한 서비스들을 QoS 요구조건에 따라 분류하고 그 요구조건에 맞도록 통계적 다중화와 간단한 구조로 스케쥴하는 AAL2/ATM 다중화 전송방안을 제안한다. 모의실험 결과 각 서비스의 QoS 요구조건을 맞출 수 있어 기존의 방법보다 더 좋은 성능이 나타남을 확인하였다.

다발 신동맥 공여자에서 손을 이용한 복강경하 공여신 적출술의 안정성

최항원,정진우,정조운,조혁진,홍성후,김준철,박용현,황태곤 대한비뇨의학회 2008 Investigative and Clinical Urology Vol.49 No.5

Purpose: We wanted to present the feasibility and safety of hand-assisted laparoscopic donor nephrectomy(HALDN) for treating patients with multiple renal arteries. Materials and Methods: Between February 2000 and July 2006, 252 patients underwent HALDN. The results for the patients with a single renal artery (n=187)(Group I) and those patients with multiple renal arteries(n=65) (Group II) were compared in terms of the donor and recipient outcomes. A retrospective chart review was performed and statistical analysis included Student's t-test, the chi square test and Kaplan-Meier survival probability analysis. Results: HALDN was technically successful in 251 patients(1 patient had to be converted to open donor nephrectomy). The operative times were increased in group II, but the differences between the groups were not statistically significant. The warm ischemic times were significantly longer in group II. The intraoperative blood loss, postoperative hospital stay and complication rate in the donor group were not associated with the number of renal arteries. The recipients' renal function and overall graft survival were similar between groups I and II. Conclusions: In our single-center study, the presence of renal artery multiplicity when performing HALDN does not have a significant impact on the outcomes of the renal donors or recipients. (Korean J Urol 2008;49:443-448) Purpose: We wanted to present the feasibility and safety of hand-assisted laparoscopic donor nephrectomy(HALDN) for treating patients with multiple renal arteries. Materials and Methods: Between February 2000 and July 2006, 252 patients underwent HALDN. The results for the patients with a single renal artery (n=187)(Group I) and those patients with multiple renal arteries(n=65) (Group II) were compared in terms of the donor and recipient outcomes. A retrospective chart review was performed and statistical analysis included Student's t-test, the chi square test and Kaplan-Meier survival probability analysis. Results: HALDN was technically successful in 251 patients(1 patient had to be converted to open donor nephrectomy). The operative times were increased in group II, but the differences between the groups were not statistically significant. The warm ischemic times were significantly longer in group II. The intraoperative blood loss, postoperative hospital stay and complication rate in the donor group were not associated with the number of renal arteries. The recipients' renal function and overall graft survival were similar between groups I and II. Conclusions: In our single-center study, the presence of renal artery multiplicity when performing HALDN does not have a significant impact on the outcomes of the renal donors or recipients. (Korean J Urol 2008;49:443-448)

다발 신동맥 공여자에서 손을 이용한 복강경하 공여신 적출술의 안정성

최향원,정진우,정조운,조혁진,홍성후,김준철,박용현,황태곤 대한비뇨기과학회 2008 Investigative and Clinical Urology Vol.49 No.5

Purpose: We wanted to present the feasibility and safety of hand-assisted laparoscopic donor nephrectomy(HALDN) for treating patients with multiple renal arteries. Materials and Methods: Between February 2000 and July 2006, 252 patients underwent HALDN. The results for the patients with a single renal artery (n=187)(Group I) and those patients with multiple renal arteries(n=65) (Group II) were compared in terms of the donor and recipient outcomes. A retrospective chart review was performed and statistical analysis included Student's t-test, the chi square test and Kaplan-Meier survival probability analysis. Results: HALDN was technically successful in 251 patients(1 patient had to be converted to open donor nephrectomy). The operative times were increased in group II, but the differences between the groups were not statistically significant. The warm ischemic times were significantly longer in group II. The intraoperative blood loss, postoperative hospital stay and complication rate in the donor group were not associated with the number of renal arteries. The recipients' renal function and overall graft survival were similar between groups I and II. Conclusions: In our single-center study, the presence of renal artery multiplicity when performing HALDN does not have a significant impact on the outcomes of the renal donors or recipients.

여성 복압성 요실금 환자에서 중부요도 슬링수술 후시행한 테이프 절단술: 1년 추적 결과

이동환,서홍진,정조운 대한배뇨장애요실금학회 2007 International Neurourology Journal Vol.11 No.1

요역동학검사 시 여성 환자의 통증과 불안에 관련한 요인

김규진,서홍진,이동환,이남석,정조운 대한배뇨장애요실금학회 2008 International Neurourology Journal Vol.12 No.1

Purpose: Urodynamic study (UDS) is widely used to evaluate voiding dysfunction, however, it is invasive and bothersome for patients because it requires catheterization into the urethra and anus. We assessed patients' anxiety and pain levels caused by UDS. Materials and Methods: A total of 60 female patients who were undergoing UDS were included in the study on a prospective basis. Anxiety level was taken prior to the procedure and pain level was taken immediately after the procedure by visual analogue scale (VAS). Just after the procedures, they were asked if they were willing to undergo the same procedure and if they could recommend the procedure to another people if medically indicated. 60 patients were divided into 2 groups: urodynamic urethral catheters (9Fr, PVC, n=30) were used in group I and Foley catheters (10Fr, Silicon, n=30) were used in group II. Results: The mean age of both groups were 45.5±5.3 (group I)and 45.5±3.8 (group II)years old. The anxiety and pain levels were relatively high, but there was no significant difference between both groups in pain level. Anxiety level prior to UDS was correlated with pain level (r=0.492, p<0.001). 42 out of 60 patients (70.0%) answered they were willing to undergo UDS if they were asked again and 37 patients (61.7%) answered they could recommend the procedure to another people. 21 patients (35.0%) were menopausal women and they showed higher anxiety level compared to non-menopausal women. Conclusion: Female patients felt anxiety before UDS and pain immediately after UDS, especially in menopausal women, and the more anxious they were, the more painful they felt. Therefore, we need to provide sufficient explanation with regard to the procedure for patients prior to UDS to diminish patients' anxiety and pain. (J Korean Continence Soc 2008;12:68-72)