구내 무선 통신 서비스 동향 분석

김학선 한국조명전기설비학회 2004 조명.전기설비 Vol.18 No.2

유비쿼터스 컴퓨팅 시대가 매우 빠르게 도래하면서 가정이나 회사의 정보 가전기기들이 초고속, 대용량을 전송하는 고속의 디지털 가전기기들로 바뀌어 가고 있으며 이들을 하나의 네트워크로 구성하고자 하는 요구가 증가하고 있다. IEEE 802.11과 IEEE 802.15.3a Task Group에서는 대량의 정보를 고속으로 통신하는 기술의 표준화를 위해 연구하고 있으며, 간단한 시스템을 이용하여 저속의 통신을 저렴한 가격으로 이루려는 또 하나의 주류인 ZigBee (IEEE802.15.4), Bluetooth (IEEE802.15.1) 시스템이 개발되고 있다. (중략)

갈륨비소 Mesfet 고이득 차동 증폭기 설계에 관한 연구 ( A Study on the Design of High Gain Gaas Mesfet`s Differential Amplifier )

김학선,이상목,이형재 대한전자공학회 1992 대한전자공학회 학술대회 Vol.1992 No.7

Evidence-Based of Nonoperative Treatment in Adolescent Idiopathic Scoliosis

김학선 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.5

Until now because there are many published journals with a variety of opinions so I will stratify these articles by giving weighted value on grade evaluation which depend on each institution (written author and co-authors) and external evaluate status (SCI, SCIE, impact factor) rather than the outcomes provided by each article. Consequently, before evaluating publicized papers, study quality assessment of each interesting paper should be performed by mean of gauging the quality of evidence. Reviewing these articles, a grade of medical literature was divided into the following 5 levels as level I (randomized controlled study), level II (non-randomized controlled study), level III (case-control study), level IV (case series), and level V (expert opinions). However, in present article I concluded only involved medical literatures with weighted value of level I and II evidence.

초고속 4 : 1 멀티플렉서의 설계 ( Design of the High-Speed 4 : 1 Multiplexer )

김학선,최병하,이형재 대한전자공학회 1988 대한전자공학회 학술대회 Vol.1988 No.1

돌발성 난청 환자에서 Carbogen 흡입과 성상신경절 차단술의 동시 치료 효과

김학선,김명구 대한이비인후과학회 2002 대한이비인후과학회지 두경부외과학 Vol.45 No.3

Background and Objectives:Impairment of inner ear circulation may be one of the pathophysiology of idiopathic suden sensorineural hearing loss (ISSNHL) 2 and 95% O 2 by mask, and a stellate ganglion block (SGB) are potent vasodilatation and tissue oxygenation procedures widely used as treatment modalities in ISSNHL. The purpose of this study was to compare the efectiveness of each modality and to find out the diferences in the effectiveness of carbogen inhalation therapy and SGB. Materials and Method:We reviewed the records of 313 patients who were admitted to the Masan Samsung Hospital from January 1995 to December 2000 for carbogen inhalation, SGB and drug medication, and 57 patients without SGB and 125 patients were treated with medication only. Results:Therapeutic results of carbogen inhalation and SGB group was better than that of medication only group. But no statistical differences were found betwen the carbogen inhalation and SGB group. Conclusion:These results suggest that carbogen inhalation and SGB were efective treatment modalities of ISSNHL. We recomend that carbogen inhalation therapy and SGB could be utilized as the standard treatment of ISSNHL. (Korean J Otolaryngol 2002;45:219-24)

아텔로콜라겐 지지체, 유전자 치료, 배양된 수핵세포를 이용한 조직 공학적 추간판의 재생

김학선,이광일,김향,권언혜,남미란,장주웅,조인제,김보람,이환모,문성환 대한척추외과학회 2010 대한척추외과학회지 Vol.17 No.2

Study Design: This is an in-vitro experiment using rabbit intervertebral disc (IVD) cells and growth factors. Objectives: We wanted to determine the effect of types I,and II atelocollagen and growth factor gene therapy for matrix regeneration of rabbit IVD cells. Summary of the Literature Review: Adenovirus-medicated growth factor gene therapy is efficient for matrix regeneration of the IVD. Atellocollagen has provided a favorable environment for matrix synthesis. However, a combined approach using gene and cell therapy in an atelocollagen scaffold has not yet been attempted. Materials and Methods: Rabbit IVD cells were transduced with Ad/TGF-β1 and Ad/BMP-2. The cells were then implanted to the atelocollagen scaffold. The [methyl-3H]thymidine incorporation for DNA synthesis and the [35S]sulfur incorporation for proteoglycan synthesis were measured. RT-PCR was performed for assessing the aggrecan, collagen type I, collagen type II and osteocalcin mRNA expressions.  Results: The rabbit IVD cells with Ad/TGF-β1 and that were cultured in type I atelocollagen showed a 130% increase in new proteoglycan synthesis, while the rabbit IVD cells with Ad/TGF-β1 and that were cultured in type II atelocollagen showed a 180% increase in new proteoglycan synthesis (p<0.05). The rabbit IVD cells with Ad/BMP-2 and that were cultured in type I atelocollagen showed a 70% increase in new proteoglycan synthesis, while the rabbit IVD cells with Ad/BMP-2 and that were cultured in type II atelocollagen showed a 95% increase (p<0.05). Rabbit IVD cells with Ad/TGF-β1 and Ad/BMP-2 and that were cultured in type I and II atelocollagen demonstrated increased collagen type I and II mRNA expressions without an osteocalcin mRNA expression (p<0.05). Conclusion: Cell and gene therapy in an atelocollagen scaffold provided a efficient mechanism for chondrogenic matrix regeneration of rabbit IVD cells. 연구 계획: 토끼의 추간판 세포와 제5형 아데노바이러스(Ad) transforming growth factor beta-1(TGF-β1), 아데노바이러스 bone morphogenetic protein-2 (BMP-2), 아텔로콜라젠을 이용한 실험적 연구목적: 제1, 2형 아텔로콜라젠과 성장 인자 유전자 치료의 토끼 추간판 세포의 기질 생성 반응을 알아보았다. 선행문헌의 요약: 아데노바이러스를 이용한 성장 인자 유전자 치료는 추간판 세포의 기질 재생에 효과적이다. 아텔로콜라젠은 추간판 세포의 기질 합성에 유리한 환경을 제공한다. 하지만 아텔로콜라젠 지지체에 유전자 치료를 병행하는 방법은 시도된 바가 없었다. 대상 및 방법: 토끼의 추간판 세포를 배양하였다. Ad/TGF-β1, Ad/BMP-2 아텔로콜라젠을 생산하였다. 추간판 세포를 Ad/TGF-β1, Ad/BMP-2에 감염시키고 이 세포를 아텔로콜라젠 지지체에 배양하였다. DNA생성은 [methyl-3H] Thymidine을 이용하였고 새로운 당단백 생성은 [35S]Sulfur를 이용하였다. 또한 전사 수준에서의 추간판세포 관련 유전자의 변화를 확인하고자 RT-PCR을 통한 aggrecan, 제 1, 2형 교원질, osteocalcin mRNA발현을 조사하였다. 결과: 제1형 아텔로콜라젠에 배양되고 Ad/TGF-β1로 유전자 전달된 추간판 세포군은 대조군에 비해 130% 신생 당단벡 생성증가가 있었고 제 2형 아텔로콜라젠에 배양되고 Ad/TGF-β1로 유전자 전달된 세포군은 180%의 신생 당단백 생성 증가가 있었다. (p<0.05) 제 1형 아텔로콜라젠에 배양되고 Ad/BMP-2로 유전자 전달된 추간판 세포군은 대조군에 비해 70% 신생 당단벡 생성증가가 있었고 제2형 아텔로콜라젠에 배양되고 Ad/BMP-2로 유전자 전달된 세포군은 95%의 신생 당단백 생성 증가가 있었다. (p<0.05) 제 1, 2형 아텔로콜라젠에 배양되고 Ad/TGF-β1, Ad/BMP-2로 유전자 전달된 세포군은 제 1, 2형 교원질 mRNA발현증가가 있었으나 (p<0.05) 어떠한 경우에도 osteocalcin mRNA발현은 없었다. 결론: 추간판 세포를 아텔로콜라젠 지지체에서 배양하고, Ad/TGF-β1, Ad/BMP-2으로 유전자 치료를 시행하여 효과적으로 연골형 기질을 생성을 유도할 수 있었다.

『몽골비사』와『만엽집』의 조사 대조연구

김학선 한국몽골학회 2003 몽골학 Vol.0 No.14

흡음재 두께가 소화노즐 소음도 저감에 미치는 영향

김학선,황인주,김윤제 한국화재소방학회 2019 한국화재소방학회논문지 Vol.33 No.1

In a gas system fire extinguishing system, extinguishing agents are usually stored with approximately 280 bar at 21℃ and are released at approximately 8 MPa through the decompression valve and orifice to quickly suppress the fire. Whenextinguishing agents are discharged, they cause a loud noise (approximately 140 dB), which can damage electronics, suchas hard disk drives (HDDs). Therefore, the noise is becoming a serious issue in the gas extinguishing system. The methodof the noise reduction by adding an absorbent is most general and in this study, the thickness of the absorbent was as aselected design variable. The noise level at the observation point and the flow characteristics inside the nozzle werenumerically calculated and analyzed using the commercial code ANSYS CFX ver. 18.1. 신속한 화재 진압을 목표로 가스계 소화 시스템에서 소화약제는 일반적으로 섭씨 21 ℃에서 약 28MPa의 고압으로 저장되며, 방출시 감압밸브와 오리피스를 지나면서 약 8MPa의 압력으로 방출한다. 때문에 방출시 약 140 dB 이상의 소음이 발생하게 되는데, 이로 인하여 hard disk drive (HDD)와 같은 전자 부품들이 손상되기도 한다. 따라서소음문제는 가스계 소화 시스템에 있어서 중요한 문제점으로 대두되고 있다. 소음문제 해결방안으로는 일반적으로흡음재를 부착하여 소음을 저감시키는 방안이 있으며, 본 연구에서는 흡음재의 두께를 설계 변수로 선정하여 유동소음을 저감하는 방안을 고찰하였다. 관측점에서의 소음도와 노즐내부 유로에 나타나는 유동특성은 상용 코드인ANSYS CFX ver. 18.1을 이용하여 수치적으로 계산하여 분석하였다.

Clinical Issues in Indication, Correction, and Outcomes of the Surgery for Neuromuscular Scoliosis: Narrative Review in Pedicle Screw Era

김학선,권지원,박건보 대한척추신경외과학회 2022 Neurospine Vol.19 No.1

Surgical treatment for neuromuscular scoliosis has evolved with pedicle screw instrumentation and the improvement of perioperative management. We aimed to review recent papers related to posterior surgical correction with a pedicle screw system for neuromuscular scoliosis, particularly cerebral palsy and muscular dystrophy, in terms of indication, correction method, and outcomes. The most remarkable change was the posterior-only operation with all-pedicle screw fixations. With this change, operation time, blood loss, and postoperative complications decreased. Furthermore, spinal osteotomy could be performed with the pedicle screw system for severe scoliosis. S2-alar-iliac screws demonstrated favorable outcomes in terms of stability and complication, but a question remains about saving the mobile segment for sitting balance, interaction between the hip and spine, effect to the sagittal balance, and proximal junctional problem. The quality of life improvement was more definite in patients with cerebral palsy. The improvement of respiratory function in Duchenne muscular dystrophy was not certain, although an increase of spinal height, thoracic cavity size, and absolute forced vital capacity have been reported. Further prospective studies or randomized clinical trials are needed to evaluate the long-term outcomes of lumbosacral fixation, preservation of the lumbosacral joint, or functional improvement considering the different etiology.

Sagittal Plane Analysis of Adolescent Idiopathic Scoliosis after VATS (Video-Assisted Thoracoscopic Surgery) Anterior Instrumentations

김학선,이종서,전병호,박진오 연세대학교의과대학 2007 Yonsei medical journal Vol.48 No.1