요통과 하지방사통에 대한 경막외 스테로이드 주입후 발생한 치명적 합병증 - 증례보고 -

김태준,김충현,정진환,백광흠,김재민,오석전,Kim, Tae Joon,Kim, Choong Hyun,Cheong, Jin Hwan,Bak, Koang Hum,Kim, Jae Min,Oh, Suck Jun 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.3

Epidural steroid injection(ESI) has been a commonly applied conservative therapy for the management of chronic low back pain and sciatica. However, there are many reports concerning various local, systemic and neurological complications related to ESI. We report two cases with fatal complications after ESI for low back pain and sciatica. In both patients, ventriculitis and meningitis were causative factors to be fatal. Aseptic procedures and careful post-procedure assessment are essential to avoid serious complications following ESI.

미세혈관 감압술중 뇌간청각유발전위 감시장치의 유용성

김태준,고용,김영수,오성훈,김광명,오석전,Kim, Tae Joon,Ko, Yong,Kim, Young Soo,Oh, Seong Hoon,Kim, Kwang Myung,Kim, Nam Kyu,Oh, Suck Jun 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.5

Objective : Surgery for the microvascular decompression is mostly concerned with injury to the cranial nerves or brain stem by cerebellar retraction. Intraopeartive brain stem auditory evoked potentials(BAEPs) has been continuously monitored on surgery to evaluate the extent of injury, recovery of the nerves and prognosis. Methods : Of the 161 cases of CP angle surgery from Feb. 1996 to Apr. 1998, 103 cases were monitored during operation. Thirty five patients who had undergone similar surgery were selected and evaluated ; 23 patients were monitored and 12 were not during surgery. If monitor showed more than 0.5 mSec delay of latency, surgeon was given a warning not to retract brain any more. If more than 1mSec delay, surgeon was informed to stop surgery and wait for the returning of evoked potentials. The level of amplitudes and delay of latencies during the initial stage of operation, opening the dura, insertion of teflon patches, and closing the dura and recovery were then compared. Resuls : Twenty patients were male and 15 were female. Their average age was 50.26 years. Mean amplitude during the initial stage of operation was $0.60{\pm}0.25mV$, at opening the dura $0.56{\pm}0.26$, after teflon patches insertion $0.49{\pm}0.20$, and after closure of dura $0.47{\pm}0.28mV$. Mean latency during the early stage of operation was $6.08{\pm}0.67mSec$, at opening of dura $6.38{\pm}0.55$, insertion of teflon $6.97{\pm}0.59$, and closing the dura $6.17{\pm}0.54$. There was statistical significance in the difference of amplitudes between each procedures, and in the difference of latencies. For the complete recovery of amplitude and latency, it usually took average 5.65 minutes(0-20 min). In monitored group, only one patient required more than 20 minutes to recover and suffered from hearing disturbance after surgery. Others were recovered within 10 minutes without complications. However, 4 out of 12 patients who were not monitored showed hearing disturbance, and 1 patient had temporary facial palsy and dizziness(p=0.000). Conclusion : The results indicate that continuous intraoperative monitoring of BAEPs during CP angle surgery is seen mandatory procedure to prevent operative complications.

체증해제 통보에 방식에 의한 IEEE 802.17 레질런트 패킷 링의 성능개선 연구

김태준,Kim Tae-joon 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.9b

근거리망의 이더넷 기술과 도시망에 적합한 링 토폴로지를 결합하여 성능이 뛰어나고 고장에 강하며 근거리망과의 호환성을 유지하는 RPR(Resilient Packet Ring)이 도시망의 핵심기술로 뜨오르고 있다. IEEE 802.11에서 RPR에 대한 표준화가 완성중인데, 공평한 대역폭의 사용을 보장하기 위해 설계된 RPR의 공정성 제어기법이 비대칭 과부하 트래픽 환경에서 성능저하를 초래하는 문제점을 안고 있다. 본 논문에서는 이러한 성능저하 문제를 해결하기 위해 체증해제 통보 기반의 공정성 제어방식을 제안하고 이의 성능을 분석한다. 제안된 방식에서는 체증 발생노드가 자신의 체증해제 여부를 판단하여 상단노드로 통보하면 상단노드는 하단노드의 체증을 해소하기 위해 제한하였던 자신의 트래픽 전송속도를 즉시 원래의 속도로 복구한다. 제안된 방식은 종래의 공정성 제어방식과 호환성을 가지며 체증해제 임계값의 선택에 의해 성능저하의 정도를 임의대로 조정할 수 있다. The IEEE 802.17 Resilient Packet Ring Working Group develops standards to support the development and deployment of Resilient Packet Ring networks in Local, Metropolitan, and Wide Area Networks for resilient and efficient transfer of data Packets at rates scalable to many gigabits Per second. It was known that the fairness algorithm of the IEEE 802.17 Resilient Packet Ring suffers from throughput degradation under an unbalanced overload. This Paper proposes a congestion release advertisement method to improve this throughput degradation and discusses its performance. Under the proposed method, a congested node decides whether its congestion is released or not. If released, it advertises the congestion release to upstream nodes, and then upstream nodes transmit their traffic without uy regulation. The proposed method is compatible with the legacy fairness algorithm.

변화된 업무환경에서 인식하는 항공사 서비스품질이 글로벌 브랜드 (항공사 조인트벤쳐) 이미지 형성에 미치는 영향 연구

김태준,김기웅,박성식,이수미,Kim, Tae-Joon,Kim, Kee-Woong,Park, Sung-Sik,Lee, Su-Mi 한국항공운항학회 2018 한국항공운항학회지 Vol.26 No.3

Terminal 2 of Incheon in'tl airport had made a grand opening since January 2018. Terminal 2 is currently operated by mainly Korean airline in cooperation with such skyteam members as Delta airline, Air France and Royal Dutch KLM. It is expected another three skyteam member airlines join the separate operation at terminal 2 since this coming winter. It is believed very meaningful research to analyze how separate operation of Global alliance of airlines affects the global brand image of an organization. To find out such effect, researchers have made an empirical analysis of perception of airline staffs working at terminal 2. This paper has focused on how the staffs perceive airline service quality in the changed working environment and on how significantly their perception on service has an effect on airline's global brand image with such moderating variables as organizational efficacy and organizational trust. According to empirical analysis using structural equation modeling, it was proven the variable of responsiveness among perceived airline service qualities had a direct significant effect on formulating airline's global brand image associated with joint venture between Korean airline and Delta airline. However, the other variables had a indirect significant effect on global brand image with moderating effects.

최적 레이턴시 기반 공정 큐잉 알고리즘의 대역폭 이용도

김태준,Kim, Tae-Joon 한국정보처리학회 2007 정보처리학회논문지 C : 정보통신,정보보안 Vol.14 No.2

널리 이용되고 있는 공정 큐잉 방식인 WFQ(Weighted Fair Queoing)는 특히 인터넷 전화와 같이 저속이지만 엄격한 지연한계를 요구하는 서비스에 대해 대역폭 이용도가 저하되는 고질적인 문제점을 갖고 있었다. 이러한 WFQ의 문제점은 흐름의 레이턴시가 최적화 되지 않았기 때문으로 최근에 밝혀졌고, 이어서 최적 레이턴시 기반 공정 큐잉 방식인 LOFQ(Latency-Optimized Fair Queuing)가 도입되었다. 그리고 LOFQ에 점유자원 최적화 기능을 추가하여 대역폭 이용도를 개선하고, 반복적으로 수행되던 자원변환 알고리즘을 개선하여 수행 복잡성을 줄이는 등 LOFQ의 성능특성이 향상되었다. 하지만 여전 시뮬레이션에 의해 성능을 평가하고 있어 평가의 정확성과 소요시간 측면에서 어려움이 있다. 따라서 본 연구에서는 LOFQ의 대역폭 이용도를 수학적으로 계산하는 방법을 연구하고자 한다. WFQ (Weighted Fair Queuing) is the most popular fair queuing algorithm, but it had the inherent drawback of a poor bandwidth utilization, particularly under the traffic requiring a low rate but tight delay bound such as internet phone, It was recently identified that the poor utilization is mainly due to non optimized latency of a flow and then LOFQ(Latency-Optimized Fair Queuing) to overcome the drawback was introduced, LOFQ was also improved through introducing an occupied resource optimization function and the implementation complexity of recursive resource transformation was reduced with revising the transformation scheme. However, the performance of LOFQ has been evaluated by means of simulation, so that there are some difficulties in evaluating the performance in the terms of the accuracy and evaluation time, In this paper, we develop how to analytically compute the bandwidth utilization in LOFQ.

RSVP-라우터간 가용자원 이동을 통해자원 이용 효율을 높이는 자원예약 방식

김태준,Kim, Tae-Joon 한국정보처리학회 2008 정보처리학회논문지 C : 정보통신,정보보안 Vol.15 No.4

서비스의 요구 품질을 보장하기 위해서 서비스의 트래픽 흐름 수용에 필요한 네트워크 자원을 예약해야 하며, 이를 위해 자원예약 프로토콜(RSVP)이 도입되었다. 그러나 경로상의 임의 RSVP-라우터가 자원부족으로 트래픽 흐름을 수락할 수 없으면 다른 RSVP-라우터에 아무리 여유자원이 많이 있다 해도 그 흐름을 수용할 수 없다. 이러한 문제를 해결하기 위해 본 논문에서 RSVP-라우터간 가용자원 이동을 통해 자원이용 효율을 높이는 자원예약 방식을 제안한다. 제안방식에서 RSVP-라우터는 최근에 연구된 최적 레이턴시 기반 공정 패킷 스케줄러를 사용한다. 평가 네트워크에 제안된 자원예약 방식을 적용한 결과 기존 방식에 비해 수용 흐름의 수를 최대 165%까지 개선할 수 있음을 확인하였다. Providing Quality-of-Service (QoS) guarantee requires the reservation of resource needed to accommodate the traffic flow of service for which resource reservation protocol (RSVP) was introduced. However, if any RSVP-capable router on the path fails to accommodate the traffic flow due to lack of resource, the flow is not allowed no matter how much surplus resources other routers on the path have. In order to solve this problem, this paper proposes a resource reservation method with available resource migration between RSVP-capable routers in which the routers use the recently developed latency optimized fair queuing scheduler. The results of the simulation applying the proposed method to an evaluation network show that it may yield the gain of up to 165% compared to that in the original one in terms of the number of admitted flows.

서버자원 이용도 측면에서 타임스탬프 기반 공평 패킷 스케줄러의 성능 비교 분석

김태준,안효범,Kim Tae-Joon,Ahn Hyo-Beom 한국정보처리학회 2006 정보처리학회논문지 C : 정보통신,정보보안 Vol.13 No.2

실시간 멀티미디어 응용의 서비스 품질을 보장하는 공평 패킷 스케줄링 알고리즘은 타임스탬프 계산시 사용되는 패킷의 기준시각 측면에서 종료시각 방식과 시작시각 방식으로 나뉜다. 전자는 트래픽 흐름의 예약속도 조정으로 원하는 레이턴시(latency) 값을 얻을 수 있어 IETF (Internet Engineering Task Force) 종합서비스 모델의 품질보장 라우터에 적용되었으나 인터넷 전화와 같이 흐름 속도가 낮지만 우수한 지연특성을 요구하는 트래픽의 경우 심각한 대역폭 손실이 발생하는 문제가 있다. 본 논문에서는 시작시각 방식을 품질보장 라우터에 적용하는 방안을 모색하기 위해 대역폭 및 페이로드(payload) 이용도 측면에서 두 가지 공평 패킷 스케줄링 방식의 성능특성을 비교 분석하였다. 분석결과 대역폭 이용도 측면에서 시작시각 방식이 우수하다는 것이 증명되었고, 모의실험결과 시작시각 방식이 최대 20%까지 높은 페이로드 이용도를 보였다. Fair packet scheduling algorithms supporting quality-of-services of real-time multimedia applications can be classified into the following two design schemes in terms of the reference time used in calculating the timestamp of arriving packet: Finish-time Design (FD) and Start-time Design (SD) schemes. Since the former can adjust the latency of a flow with raising the flow's reserved rate, it has been applied to a router for the guaranteed service of the IETF (Internet Engineering Task Force) IntServ model. However, the FD scheme may incur severe bandwidth loss for traffic flows requiring low-rate but strong delay bound such as internet phone. In order to verify the usefulness of the SD scheme based router for the IETF guaranteed service, this paper analyzes and compares two design schemes in terms of bandwidth and payload utilizations. It is analytically proved that the SD scheme is better bandwidth utilization than the FD one, and the simulation result shows that the SD scheme gives better payload utilization by up to 20%.

송신자사서함 기반의 메일 방식에 관한 연구

김태준,Kim, Tae-Joon 한국정보처리학회 2004 정보처리학회논문지 C : 정보통신,정보보안 Vol.11 No.5

기존의 메일방식은 수신자사서함 기반의 구조적 특성으로 인해 스팸메일이 남발되고 송신자가 수신자사서함에 접근할 수 없어 발송된 메일을 수신자가 있었는지의 여부를 확인하기가 어렵다. 본 논문에서는 기존 메일방식의 구조적 문제점을 개선하기 위해 송신자가 발송한 메일을 송신측 메일서버내 송신자사서함에 보관하는 송신자사서함 기반의 메일방식을 연구하고 이의 성능을 평가하였다. 새로운 메일방식에서는 메일 원본이 수신자가 읽어갈 때까지 송신자사서함에 보관되므로 기존 수신자가 겪었던 사서함 관리와 스팸메일 삭제 등의 부담을 송신자가 떠 안게 되고, 송신자가 자신의 메일을 수신자가 메일을 읽어갔는지의 여부를 자신의 송신자사서함 상태를 확인함으로써 수신자의 의도와 상관없이 쉽게 알 수 있다. 성능평가 결과 스팸메일의 비율이 90%이고, 다중메일의 비율이 80% 일 경우 사서함 공간은 75%, 메일 트래픽은 90% 절감되는 효과를 보였다. The conventional email method based on a recipient mailbox has a structural weakness, which may cause the spam message problem and the extreme waste of recipient mailbox space, and also require an explicit recipient notification scheme. This paper proposes a new email method based on a sender mailbox and evaluates its performance. Under the new email method, a message is stored at sender mailbox instead of recipient one until an intended recipient reads the message, so that the burden of mailbox management such as removing spam message is now shifted to sender side. And also a sender can confirm whether an intended recipient has read his or her message by simply rummaging his or her sender mailbox. The results of Performance evaluation show that 75% of mailbox space and 90% of message traffic are reduced in conditions that the portions of spam message and multicasting message are 90% and 80%, respectively.

다중 충돌의 영향을 고려한 쇼트피닝의 유한요소해석

김태준,김낙수,박순철,정원욱,Kim, Tae-Joon,Kim, Nak-Soo,Park, Soon-Cheol,Jeong, Won-Wook 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.12

Multiple impact models to examine the effect of stress interference are proposed and investigated. The single shot model analysis, which used various shot ball conditions, was carried out to compare with multiple impacts analysis. Then the multiple impact analysis were performed to predict the effect of the shot ball distances. The results showed that the stress interference in the multiple impact model significantly reduced the maximum value of the compressive residual stresses. The residual stress profiles were strongly effected by the shot ball distances. The multiple impact model can simulate a realistic shot peening process rather than a single shot model does. It is concluded that the proposed model predicts the real process more accurately.

VE에 대한 올바른 이해

김태준,Kim, Tae-Joon 한국기술사회 2006 技術士 Vol.39 No.4

Value Engineering(VE) is the systematic activity to make a Alternatives for user's needs with an access by function analysis, creative thoughts, and the lowest life cycle cost. However, the current activity called VE is to make a Alternatives by experience and to make a report in similar to VE format. The right understanding of the concept and the process of VE is required for more effective Alternatives and VE activity with reliability.