제 I 형 신경섬유종증에 병발하였던 종격동내 횡문근육종에 의한 척수압박 1례 - 증례보고 -

김세윤,황금,홍순기,변진수,허철,김헌주,한용표,이명섭,이종국,조미연,Kim, Sei-Yoon,Whang, Kum,Hong, Soon-Ki,Pyen, Jhin-Soo,Hu, Chul,Kim, Hun-Joo,Han, Young-Pyo,Lee, Myoung-Sup,Lee, Chong-Kook,Cho, Mee-Yon 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

A 12-years-old female admitted to the hospital with the complaint of pain on the right upper chest area which persisted about 1 month prior to admission. $Caf{\acute{e}}$-au-lait spots of various size laying on a whole body and freckling on the axilla were found on physical examination. A huge mass was found on the plain chest X-ray and on chest MRI. The mass encroached thoracic spine, posterior rib, back muscles, and then into the neural canal and compressed thoracic spinal cord. On the 5th day of hospitalization, the patient complained tingling on the both legs and 2 days later, monoparesis on the right leg. Open thoracotomy and decompressive laminectomy was done to remove mass. Pathologic reports confirmed rhabdomyosarcoma, embryonal type.

광대역 동축-마이크로스트립 수직 트랜지션의 전송 손실 저감 설계

김세윤,노진입,정지영,안병철,유영갑,Kim, Sei-Yoon,Roh, Jin-Eep,Chung, Ji-Young,Ahn, Bierng-Chearl,You, Young-Gap 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.11

A design method for minimizing transmission loss of a broadband right-angle transition from a coaxial cable to a microstrip line is presented. The right-angle transition has been widely used where printed circuit applications need to be fed from behind the ground plane using coaxial line. To obtain the minimized transmission loss over the whole operating frequency range of the transition, design parameters such as ground aperture and probe diameters, ground aperture offset, and stub length are optimized using a commercial electromagnetic simulation software. Results are presented for the optimum right-angle transition from an SMA connector to a microstrip line on common reinforced 0.787 mm thick PTFE substrates. Measurements of a fabricated transition show that reflection coefficient is less than -22 dB and insertion loss is less than 0.45 dB over $0.05{\sim}20GHz$. 본 논문에서는 광대역 동축-마이크로스트립 선로에서 전송 손실을 최소화하는 수직 트랜지션(transition)의 설계 기법을 제안하였다. 동축-마이크로스트립 선로의 수직 트랜지션은 동축 선로와 인쇄 회로 기판이 수직으로 연결되는 구조로서 인쇄형 안테나 혹은 마이크로스트립 기판을 사용하는 마이크로파 송수신 장치 등에 널리 사용된다. 제안한 설계 방법은 넓은 대역폭을 가지면서 전송 손실을 최소화하는 방법으로, 접지 개구면(ground aperture)의 지름, 프로브(probe)의 지름, 접지 개구면의 오프셋과 스텁(stub) 길이를 설계 변수로 설정하여, 시뮬레이션을 통하여 설계 값을 구하였다. 동축 선로와 마이크로스트립 기판은 일반적으로 널리 사용되는 SMA 커넥터와 PTFE 재질의 두께 0.254, 0.508 및 0.787 mm 기판을 사용하였다. 시뮬레이션 결과로부터 구한 설계 변수 값들을 입증하기 위하여 SMA 동축 커넥터와 0.787 mm 두께의 기판을 사용하여 수직 트랜지션 시험 블록을 제작하였다. 이 트랜지션의 특성을 측정한 결과 $0.05{\sim}20GHz$주파수 범위에서 반사 계수가 -22 dB 이하이고, 전송 손실이 0.45 dB 이하인 만족할만한 결과를 얻었다.

쇄기형 유전체의 양면에 평면파 입사시 다극전개를 이용한 회절패턴 계산

김세윤,나정웅,신상영,Kim, Se-Yun,Ra, Jung-Woong,Shin Sang-Yung 대한전자공학회 1989 전자공학회논문지 Vol. No.

임의의 각을 가진 쇄기형 유전체의양 경계면을 E-편파된 평면화가 입사할 경우 발생하는 전자파의 회절패턴을 기하광학해와 모서리회절파의 합으로 표시하였다. 모서리 회절파의 회절계수는 물리광학근사로 구한 회절계수를 모서리 끝에 분포한 다극선전원으로 수정하여 구하였다. 쇄기각 $120^{circ}$, 입사각 $60^{circ}$ 인 유전체의 비전율을 2, 5, 10으로 변화시키고, 측정거리도 모서리 끝점으로 부터 5와 10파장인 경우에 대해 기하광학해와, 물리광학해, 다극선전원으로 교정한 수정해 순으로 각각의 회절패턴을 그림으로 나타내었다. 본 논문에서 구한 수정해는 모서리 끝점으로 부터 멀리 떨어진 곳에서만 유용한 점근해임을 알 수 있으나, 유전체 경계면에서 경계조건을 만족함을 보였다. Diffraction patterns of electromagnetic fields for the incidence of E-polarized plane wave on both interfaces of an arbitrary-angle dielect wedge are obtained by sum of geometric optics term and the edge diffracted fields. The diffraction coefficients of the edge diffracted fields are evaluated by employing the physical optics approximation and then correcting its error with the multipole line source at the dielectric edge. For the wedge angle $120^{circ}$, the incident angle $60^{circ}$, the relative dielectric constant of the dielectric wedge, 2, 5, and 10, and the observation distance from the tip of the wedge, 5 and 10 wavelength, the diffraction coefficients and the diffraction patterns corresponding to geometric optics, physical optics, and the solution corrected by the multipole line source are plotted, respectively. While the corrected solutions presented in this paper are valid only in the far-field region, these asymptotic solutions show to satisfy the boundary condition on the dielectric interfaces.

Mulligan의 Sustained Natural Apophyseal Glides Mobilization이 만성 요통 환자의 요부근 활성도에 미치는 효과

김세윤,김난수,Kim, Se-Yoon,Kim, Nan-Soo 대한물리치료학회 2013 대한물리치료학회지 Vol.25 No.1

Purpose: Low back pain occurs and frequently recurs in many people. An imbalance of paraspinal muscle activity can cause low back pain. Mulligan's concept of mobilizations with sustained natural apophyseal glides (SNAG) is a common method for treating low back pain. The purpose of this study was to investigate the effects of this method on paraspinal muscle activity in patients with chronic low back pain. Methods: Twenty-one patients with low back pain participated in this study. Patients were classified using the Oswestry disability index. The subjects' paraspinal muscles were measured by surface electromyography both before and after the SNAG mobilization. We measured the root mean square value of the paraspinal muscles during lumbar flexion and extension. Results: Paraspinal muscle activity in patients with chronic low back pain was different between the right and left sides. Importantly, paraspinal muscle activity significantly decreased after using the SNAG mobilization method. Conclusion: This study shows a difference between paraspinal muscle activity in chronic low back pain patients and finds that the Mulligan's concept of SNAG mobilization is effective at reducing imbalances in paraspinal muscle activity in low back pain patients.

그라파이트 혼입량에 따른 에너지 저장 콘크리트의 미세구조 및 열전도도 분석

김세윤,김성조,서지우,한동석,Kim, Se-Yun,Kim, Sung-Jo,Suh, Jeewoo,Han, Tong-Seok 한국전산구조공학회 2021 한국전산구조공학회논문집 Vol.34 No.5

본 논문은 에너지를 실시간으로 저장할 수 있는 저장장치 중 열에너지 저장 콘크리트를 대상으로 재료의 미세구조와 물성(열전도도)의 상관관계를 분석하는 연구를 수행하였다. 에너지 저장 콘크리트의 열전도 성능을 증가시키기 위해 혼화재인 그라파이트(graphite)를 사용하였다. 그라파이트가 시멘트 질량의 10%와 15%를 치환한 시편과 일반 콘크리트(OPC) 시편을 제작하여 그라파이트의 혼입에 따른 미세구조 변화 및 열전도도의 영향을 마이크로 스케일에서 분석하였다. 마이크로-CT를 활용하여 OPC와 그라파이트를 사용한 콘크리트의 공극률을 비교하였으며, 확률함수를 사용하여 미세구조 특성을 정량화하였다. 미세구조 특성 차이가 열전도도에 미치는 영향을 확인하기 위해 3차원 가상 시편을 제작하여 열해석을 수행하였으며, 이를 열평판법을 사용하여 측정한 열전도도 실험 결과와 비교하였다. 열해석 수행 시 그라파이트 재료가 지닌 열전도도 성능을 반영하기 위하여 해석 결과와 실험 결과를 기반으로 고체상의 열전도도를 역해석을 통해 계산하였으며, 그라파이트가 시편의 열전도도에 미치는 영향에 대해 분석하였다. In this study, the microstructure and thermal conductivity correlation was investigated for concrete materials used in concrete thermal energy storage (CTES) among real-time energy storage devices. Graphite was used as admixture to increase the thermal conductivity performance of the CTES. Concrete specimens of 10% and 15% substitution of cement by mass with graphite, as well as ordinary portland cement (OPC) specimens were prepared, and the microstructural changes and effects on thermal conductivity were analyzed. Porosities of OPC and concrete with graphite were compared using micro-CT, and the microstructural characteristics were quantified using probability functions. Three-dimensional virtual specimens were constructed for thermal analysis, to confirm the effect of microstructural characteristics on thermal conductivity, and the results were compared with the measured conductivity obtained using the hot-disc method. To identify thermal conductivity of graphite for thermal analysis, solid phase conductivity was inversely determined based on simulation and experimental results, and the effect of graphite on thermal conductivity was analyzed.

압전 소자형 광섬유 격자 소자를 이용한 파장 분할 다중화 시스템용 파장 가변형 광 분기/결합 장치

김세윤,이상배,최상삼,정준,정지채,Kim, Se-Yoon,lee, Sang-Bae,Choi, Sang-Sam,Chung, Joon,Jeong, Ji-Chai 한국광학회 1997 한국광학회지 Vol.8 No.4

기존의 광섬유 격자 소자를 이용한 광 분기/결합 장치들이 광섬유 격자 소자의 브래그 파장에 해당하는 신호만을 선택할 수 있었던 단점을 극복하기 위해 압전 소자에 광섬유 격자 소자를 부착한 압전 소자형 광섬유 격자 소자를 제작하고, 이러한 압전소자형 광섬유 격자 소자와 편광 선속분할기를 이용하여 파장 분할 다중화 시스템용 파장 가변형 광 분기/결합 장치를 제안하고 실험하였다. 본 장치는 두 빛의 편광 상태를 이용하여 광섬유 격자 소자에 해당하는 파장의 신호를 분기/결합하는 장치로서 외부의 온도 변화에 크게 영향을 받지 않는 안정적인 특성을 보였다. 압전 소자에 전압을 인가함으로써 광섬유 격자 소자의 브래그 파장에 해당되는 신호(1549.3 nm)뿐만 아니라 가변된 파장(1550.1 nm)의 신호도 분기/결합할 수 있었다. 파장을 가변하지 않을 경우와 파장을 가변했을 경우 모두 광섬유 격자 소자에 의해 분기된 신호와 인접 채널 신호간의 차이 -26 dB 이하였으며 분기된 신호 중 광섬유 격자 소자를 통해 나오는 누설 신호는 -34 dB였다. We proposed and demonstrated a tunable wavelength optical add/drop multiplexer(OADM) employing piezoactuated fiber grating pairs and polarization beam splitters. We used piezostack act as a fiber stretcher, using the fact that the resonant wavelength of the grating can be controlled by the axial strain along the fiber grating. The polarization controlled configuration showed high stability because the reflected signals from the two identical gratings are dropped or added not by interference but by polarizations of the beams. We could add and drop not noly 1549.3nm signal channel(original gratings), but also 1550.1nm(tuned gratings) with PZT actuators and in both cases, we found that the rejection of adjacent channels was more than -26dB, and signal leakage at the gratings was less than -34dB.

경증 두부외상 환자에서 MR FLAIR 영상의 임상적 유용성

김세윤,황금,김헌주,이명섭,Kim, Sei-Yoon,Whang, Kum,Kim, Hun-Joo,Lee, Myoung-Sup 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.10

Objectives : MR fluid-attenuated inversion recovery(FLAIR) image uses paired long inversion time and relaxation time that nulls the signal from CSF. With nulling of the CSF long echo time readout could be used to increase T2-weighting, hence improving the conspicuousness of most tissue lesions without the deleterious effects of CSF artifact seen on T2 weighted sequence. We examed the usefulness of FALIR image in the diagnosis of mild head injury. Methods : A total of 38 patients with mild head injury were examined by FLAIR image. We compared those images with CT scan and T1, T2-weighted images. Careful observation of MR images were done by two well-trained neuroradiologists. Each image was compared for conspicuousness and detectability of traumatic lesions might have shown abnormal signal intensities. The Wilcoxon signed ranks test was used for statistical evaluation. Results : The FLAIR image was significantly more sensitive than those of other images(p<0.001). T2 FFE(Fast Field Echo) image was more useful for detection of small petechial hemorrhages. Conclusion : FLAIR image is considered to be more sensitive than those of conventional MR images in the evaluation of mild head injuries.

삼정환(三精丸)이 대식세포의 면역반응에서 유도되는 $IL-1{\beta}$ 유전자의 발현에 미치는 영향

김세윤,정지천,Kim, Se-Yoon,Jeong, Ji-Cheon 대한한방내과학회 2006 大韓韓方內科學會誌 Vol.27 No.1

Objectives : Macrophage has an important innate defense role in the immune system. When we are infected with pathogens, macrophage ingests them through phagocytosis or endocytosis, and then secretes many cytokines, such as IL-1, IL-6 and $TGF{\alpha}$, which are regulators of immune responses. The aim of this study is to determine how Samjunghwan effects the expression of cytokine and other immune-related genes in macrophages. Methods : Cells were treated directly with Samjunghwan and/or LPS at regular intervals. Total RNA of cells was isolated using TRIzol reagent, and the changes in cytokine gene expressions were investigated using RT-PCR, western blot and ELISA. Results : $IL-1{\alpha},\;IL-1{\beta}$ and COX-2 genes were inducibly expressed specifically by Samjunghwan in macrophage. Especially, $IL-1{\beta}$ gene was induced most strongly by treatment with Samjunghwan. Over time, treatment with Samjunghwan showed that the expression levels of $IL-1{\alpha}\;and\;$IL-1{\beta}$ genes increased from 1 to 4h, and then decreased from 4 to ISh. However, the expression level of COX-2 gene increased continuously up to 11h. $IL-1{\alpha},\;IL-1{\beta}$ and COX-2 genes were expressed synergistically by a simultaneous treatment of both Samjunghwan and LPS in macrophages. Secretion levels of translated $IL-1{\beta}$ increased continuously up to 11h. Conclusions : Though this study is only a start in the investigation of the efficasy of Samjunghwan, these results suggest that Samjunghwan has positive effects on immune responses.

쇄기형 유전체의 앙면에 평면파 입사시 Neumann전개를 이용한 회절패턴 계산

김세윤,나정웅,Kim, Se-Yun,Ra, Jung-Woong 대한전자공학회 1989 전자공학회논문지 Vol. No.

임의의 각을 갖는 쇄기형 유전체의 양 경계면에 E-편파된 입사시 전자파의 회절문제에서 쇄기형 유전체의 모서리 근방에서 정전기적 극한의 모서히 조건을 만족하는 해를 구하였다. 물리광학근사로 구한 회절계수를 유전체 경계면을 따라 분포한 Neumann 전개된 면전류로 교정하였다. 모서리 끝점에 분포한 다극선전원으로 교정된 회절계수에 비하여, 본 논문에서 구한 회절계수는 유전체 내부의 비유전율을 점차 크게 할 경우 좀 더 정확히 쇄기형 완전도체의 회절함수에 접근함을 보았다. The electromagnetic diffraction problem for the incidence of E-polarized planewave on both interfaces of an arbitrary-angled dielectrc wedge is solved in conjunction with the edge condition near the tip of dielectric wedge in the static limit. The diffraction coefficients obtained by the tip of the wedge, the diffraction coefficients presented in this paper approach more closely to the exact pattem of a perfectly conducting wedge as the relative dielectric constants of the dielectric wedge increase.

고체입자가 부상된 이상유동에서 운반유체의 난류강도에 대한 해석적 접근

김세윤,이충구,이계복,Kim, Se-Yun,Lee, Chung-Gu,Lee, Kye-Bock 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.6

The purpose of this research is to develop the model of turbulence modulation due to the presence of particles in various types of particle-laden flows Available experimental data are surveyed and the dependence of turbulence modulation of carrier-phase on particle size, concentration and. particle Reynolds number are examined. This study takes into account the effect of wake produced by particle, the drag between phases and the velocity gradient in the wake to estimate the production of turbulence. The model of turbulence modulation using the mixing length theory under the assumption of equilibrium flow is proposed. Numerical results show that the model is successful in predicting the characteristics of the particle-laden in various flow conditions both qualitatively and quantitatively.