태풍피해와 국가의 대비태세

이상권,Lee, Sang-Gwon 한국수자원학회 2016 물과 미래(한국수자원학회지) Vol.49 No.8

소아 백혈병에서 중추신경계 예방 치료에 따른 백질뇌병증:자기공명영상 소견

이상권,김태헌,김용주,강덕식,Lee, Sang-Gwon,Kim, Tae-Heon,Kim, Yong-Ju,Gang, Deok-Sik 대한영상의학회 2001 대한영상의학회지 Vol.45 No.4

Purpose: To evaluate the MR imaging findings and the usefulness of MR imaging in the diagnosis and follow-up of leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia. Materials and Methods: We retrospectively evaluated the MR imaging findings of eight children with white matter abnormalities on MR out of seventeen acute leukemic patients with various neuropsychiatric symptoms who received intrathecal methotrexate administration, with or without cranial irradiation. In all cases, initial MR was performed within a week of the onset of neuropsychiatric symptoms. Follow-up MR was performed one to sixteen months after initial study, and the MR imaging findings were compared with the initial findings. Results: The initial MR imaging findings were classified into three categories: focal or multifocal white matter abnormalities (3/8), and diffuse white matter abnormalities without enhancement (3/8), and diffuse white matter abnormalities with enhancement (2/8). At follow-up MR, diffuse or focal atrophic changes were noted in all children. White matter abnormalities improved in two out of three patients with focal or multifocal white matter abnormalities. In five with diffuse white matter abnormalities, the extent of these showed no significant change, but contrast enhancement was markedly reduced in two children in whom diffuse white matter abnormalities with enhancement had been demonstrated. Conclusion: In pediatric leukemia, the MR imaging findings of leukoencephalopathy following CNS prophylaxis therapy are variable, but are specific with the clinical history of neuropsychiatric symptoms after intrathecal methotrexate administration, with or without cranial irradiation. The MR imaging is valuable in the diagnosis and follow-up of leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia.

연속 웨이블렛 변환의 확대된 위상 지도를 이용한 기어의 초기 퍼팅 결함 진단

이상권,심장선,Lee, Sang-Gwon,Sim, Jang-Seon 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.11

Vibration transient generated by developing localized fault in gear can be used as indicators in gear fault detection. In this paper, we propose the zoomed phase map for a fault signal using continuous wavelet transfers to detect this vibration transient. Local fault induces the abrupt fluctuation of load exciting tooth and phase lag in the vibration signal measured on the gearbox. The relatively large fault like "tip breakage" easily can be detected by the clear fluctuation of exciting load. However, minor fault like "initial pitting"cannot be detected using the load fluctuation. To defect this kind of minor fault, the phase map for a fault signal is taken into account. The phase lag by minor fault is observed well in the zoomed phase map.

KDSM(KAIST Distributed Shared Memory) 시스템의 설계 및 구현

이상권,윤희철,이준원,맹승렬,Lee, Sang-Kwon,Yun, Hee-Chul,Lee, Joon-Won,Maeng, Seung-Ryoul 한국정보과학회 2002 정보과학회논문지 : 시스템 및 이론 Vol.29 No.5

본 논문에서는 KDSM(KAIST Distributed Shared Memory) 시스템의 설계 및 구현에 관해서 설명한다. KDSM은 Linux 2.2.13 상에서 실행되는 사용자 수준 라이브러리로 구현되었고, TCP/IP를 기반 통신 구조로 사용한다. KDSM은 페이지 기반 무효화 프로토콜(page-based invalidation protocol)과 다중 쓰기 프로토콜(multiple writer protocol)을 기반으로 하고, HLRC(Home-barred Lazy Release Consistency) 메모리 일관성 모델을 사용한다. KDSM의 성능을 측정하기 위해서 4개의 과학계산용 응용 프로그램을 실행하여 JIAJIA와 성능 비교를 하였다. 그 결과, 2개의 응용은 같은 결과를 냈고, 나머지 2개는 KDSM의 성능이 우수하였다. In this paper, we give a detailed description of KDSM(KAIST Distributed Shared Memory) system. KDSM is implemented as a user-level library running on Linux 2.2.13, and TCP/IP is used for communication. KDSM uses page-based invalidation protocol, multiple-writer protocol, and supports HLRC(Home-based Lazy Release Consistency) memory consistency model. To evaluate performance of KDSM, we executed 4 scientific applications and compared the result to JLAJLA. The results showed that performance of KDSM almost equal to JIAJIA for 2 applications and performance of KDSM is better than JIAJIA for 2 applications.

상악 제1소구치에서 전부도재관의 finish line 형태에 따른 파절강도와 응력 분포에 관한 연구

이상권,동진근,Lee, Sang-Kwon,Dong, Jin-Keun 대한턱관절교합학회 2003 구강회복응용과학지 Vol.18 No.2

he purpose of this study was to compare the fracture resistance of the IPS Empress ceramic crown with 1.0mm width rounded shoulder, which is usually recommended in all ceramic crown, and 0.5mm width chamfer finish lines on the maxillary first premolar. 30 sound maxillary first premolars were selected and then storaged in 5% NaOCl and saline. 15 teeth were performed preparation for each group(1.0mm rounded shoulder, 0.5mm chamfer). After 30 stone dies were made for each group, the IPS Empress ceramic crowns were fabricated and cemented with resin cement(Bistite resin cement, Tokuyama Soda Co. LTD., Japan) on the natural teeth. The cemented crowns were mounted on the positioning jig and the universal testing machine(Zwick Z020, Zwick Co., Germany)was used to measure the fracture strength, with stress loading on the occlusal surface between buccal and lingual cusp. And also, three-dimensional finite element model was used to measure the stress distribution with two types of the finish lines(1.0mm rounded shoulder, 0.5mm chamfer) and two loading conditions(both buccal and lingual cusp inclination, lingual cusp inclination only). The result of the this study were as follows. In the fracture resistance experiment according to the finish line, the mean fracture strength of rounded shoulder(842N) showed higher value than that of the chamfer(590N) (p<0.05). In the three dimensional finite element analysis of all ceramic crown, metal die and natural teeth model did not show any differences in stress distribution between finish lines. Generally, when force was loaded on the occlusal inclination of buccal and lingual cusp, the stress was concentrated on the loading point and the central groove of occlusal surface. When force was loaded only on the occlusal inclination of lingual cusp, the stress was concentrated on the lingual finish line and loading point.

Anti-apoptotic Activity of Heme Oxygenase-1 Up-regulated by Etoposide in Human Retinal Pigment Epithelial Cells

이상권,송주동,김강미,김종민,이상률,유영현,박영철,Lee, Sang-Kwon,Song, Ju-Dong,Kim, Kang-Mi,Kim, Jong-Min,Lee, Sang-Yull,Yoo, Young-Hyun,Park, Young-Chul Korean Society of Life Science 2007 생명과학회지 Vol.17 No.9

The topoisomerase II inhibitor etoposide causes an accumulation of DNA double strand breaks within the nuclei of cells. In this study, we investigated the effect of etoposide on the cell growth and apoptosis of human RPE cells. Etoposide evoked a significant inhibition of cell growth, and also induced DNA fragmentation in ARPE-19 cells. In addition, etoposide significantly up-regulated the expression of heme oxygenase-1 (HO-1), which is a stress-responsive protein and is known to play a protective role against the oxidative injury. And, etoposide-induced HO-1 expression was affected by the ROS scavenger N-acetyl cysteine. We also used oligonucleotides interfering with HO-1 mRNA (siRNA) for the inhibition of HO-1 expression. Interestingly, knock-down of the HO-1 gene significantly increased the level of DNA fragmentation in etoposide-treated ARPE-19 cells. In conclusion, these results suggest that up-regulated HO-1 plays as an anti-apoptotic factor in the process of apoptosis of ARPE-19 cells stimulated by etoposide.

비가시선 영역의 통신 단절 현상 개선과 커버리지 확장을 위한 VLC 릴레이 모듈 구현

이상권,이대희,오창헌,Lee, Sang-gwon,Lee, Dae-hee,Oh, Chang-heon 한국정보통신학회 2018 한국정보통신학회논문지 Vol.22 No.1

Recently, VLC(Visible Light Communication) fusing with LED(Light Emitting Diode) used in indoor lighting and wireless communication technology has attracted attention. However, the VLC can communicate only within the coverage to measure the optical signal and the communication disconnection phenomenon is occur in the NLoS(Non-Line-of-Sight) area. In this paper, we propose VLC relay module to extend the coverage of VLC and improve the communication disconnection phenomenon in NLoS area. The proposed VLC relay module transmits the packet received from the transmitter to the VLC relay module and receiver. The experiment was carried out by installing one VLC transmitter and three VLC relay modules, communication coverage expansion and the improvement of communication disconnection phenomenon in the NLoS were confirmed by the increase of the VLC relay module. Also, we confirmed that the optical signal measurement performance is improved 2.4 times by using the dual sampling method.

Thinking Science 프로그램의 적용에서 지연검사에 의한 중학생들의 인지발달 가속 효과의 분석

이상권,최병순,신애경,이종백,백명화,Lee, Sang-Kwon,Choi, Byung-Soon,Shin, Ae-Kyung,Ree, Jong-Baik,Paek, Myeong-Hwa 대한화학회 2007 대한화학회지 Vol.51 No.6

The purpose of this study was to investigate cognitive acceleration effect of the experimental group over three years compared with the control group through the ‘Thinking Science' program in the middle school students. The ‘Thinking Science' program was implemented to 168 students in 7th grade over a period of two years. After implementation of the ‘Thinking Science' program, the improvement of formal thinking ability of the students was almost twice examined with SRT VII as the post-test and the delayed test. It was shown that by the end of the implementation period the experimental group had achieved a significantly greater gain score in levels of cognitive development than had the control group. In the subsequent year during which there was no further implementation, the experimental group continued to develop at the same rate as the control group. However, it is clear that much more experimental students in mature concrete operational stage shifted to formal operational stage in delayed test. The results were also analyzed by gender, and cognitive levels of the students. In the post-test, the ratio of girls that shifted to formal operation stage in the experimental group increased as compared with the ratio of boys, while, in the delayed test cognitive level of boys was more effective than that of girls.

학술 5 - 어린 연령의 개의 흉벽에서 발생한 골외성 골육종 증례

이상권,Lee, Sang-Gwon 대한수의사회 2014 대한수의사회지 Vol.50 No.7

성인에서의 우전외측 개흉술을 이용한 개심술

이상권,김상필,송현,김종욱,송명근,이재원,Lee, Sang-Gwon,Kim, Sang-Pil,Song, Hyun,Kim, Jong-Ook,Song, Meung-Gun,Lee, Jae-Won 대한흉부심장혈관외과학회 1999 Journal of Chest Surgery Vol.32 No.8

Background: To secure a rapid and safe approach which is at the same time cosmetically appealing, we employed the right anterolateral thoracotomy incision for repair of atrial septal defects and valvular heart diseases in the adult. Material and method: Between October 1989 and June 1998, 44 adult patients underwent open heart surgery through right anterolateral thoracotomy at our institution. Operative time, cardiopulmonary bypass time, aortic cross clamp time, blood loss until chest tube removal, length of ICU stay, days to discharge, and survival were compared with those that received cardiac surgery via conventional sternotomy. Result: No significant differences were observed between the two groups. There was no death and no additional morbidity directly related to this approach. Cosmetically satisfying results were obtained with safety using the right anterolateral thoracotomy approach. Conclusion: Our data show that the right anterolateral thoracotomy approach is a safe alternative to conventional median sternotomy as it offers excellent exposure and aesthetically more acceptable wounds while not adding on to the operative risks.