광증폭 야시장비의 현황 및 발전추세

권우근,Gwon, U-Geun 한국방위산업진흥회 1992 國防과 技術 Vol.- No.158

예로부터 수많은 전투가 야간의 기습공격 형태로 수행되어 왔으며, 최근의 걸프전은 물론이고 '80년대초의 포크랜드 전쟁에서 영국군이 하룻밤 사이에 포크랜드를 완전장악하여 세상을 놀라게 했던 사실은 새삼 야시장비가 얼마나 중요한가를 일깨워 주는 교훈이라고 할수 있다. 더구나 한반도에서와 같이 군사적인 대립관계가 계속되고 있고, 국지적인 적의 침투 가능성이 상존하고 있는 상황하에서 야시장비의 중요성은 더욱 크다고 할수 있다 여기서는 광증폭 야시장비의 기술적인 특성 및 선진국의 개발현황과 앞으로의 발전추세에 대해 살펴보기로 한다

Why Endoscopic Spine Surgery?

권우근,김세훈 대한척추신경외과학회 2023 Neurospine Vol.20 No.1

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Full Endoscopic Ligamentum Flavum Sparing Unilateral Laminotomy for Bilateral Recess Decompression: Surgical Technique and Clinical Results

권우근,Katherine A. Kelly,Malia McAvoy,Sananthan Sivakanthan,John Ogunlade,Natalie Kai Yi Yap,Sharon Durfy,Christoph P. Hofstetter 대한척추신경외과학회 2022 Neurospine Vol.19 No.4

Objective: Interlaminar endoscopic spine surgery has been introduced and utilized for lumbar lateral recess decompression. We modified this technique and utilized it for bilateral lateral recess stenoses without significant central stenosis. Here we present the surgical details and clinical outcome of ligamentum flavum sparing unilateral laminotomy for bilateral recess decompression (ULBRD). Methods: Prospectively collected registry for full-endoscopic surgeries was reviewed retrospectively. One hundred eighty-two consecutive cases from a single center between September 2015 and March 2021 were reviewed and 57 of them whom underwent ULBRD were enrolled for analysis. Basic patient demographic data, perioperative details, surgeryrelated complications, and clinical outcome were reviewed. The detailed surgical technique is presented as well. Results: Among the 57 patients enrolled, 37 were males while the other 20 were females. The mean age was 58.53 ± 14.51 years, and a bimodal age distribution at the age of mid-fifties and mid-sixties or older was noted. The later age-peak was related to coexistence of degenerative scoliosis. The average operative time per lamina was 70.34 ± 20.51 minutes and mean length of stay was 0.56 ± 0.85 days. Four perioperative complications were reported (7.0%) and the overall reoperation rate at the index level within 1 year was 8.8%. The preoperative back/leg visual analogue scale scores and functional outcome scales including EuroQol-5 dimension questionnaire, Oswestry Disability Index presented significant improvement immediately after surgery and were maintained until final follow-up. Conclusion: ULBRD for bilateral lateral recess stenoses without significant central stenosis resulted in good clinical outcomes with acceptably low perioperative complications rates. Sufficient decompression was achieved with the central ligamentum flavum being preserved.

정찰위성의 현황과 발전

권우근,Gwon, U-Geun 한국방위산업진흥회 2000 國防과 技術 Vol.- No.255

새천년이 시작되는 21세기는 정보산업의 시대이고, 우리 군의 미래전력도 정보획득능력에 의해 결정될 것임은 부인할 수 없는 사실이다. 이제, 인공위성 이야기는 더 이상 우리의 머리위를 떠돌아 다니는 "남의 별"들의 이야기가 아닌, "우리 별"의 이야기여야 한다. 미국이나 프랑스를 중심으로 하는 위성 선진국들이 엄청난 규모의 위성시장을 놓고 눈에 보이지 않는 전쟁을 하고 있는 이 시기에, 2000년대를 맞이한 우리의 과제가 무엇인지는 명확해진다.

고해상도 광학영상장비 반사경 구조해석

권우근(Woo-Gun KWON),김광로(Kwang-Ro KIM),이영신(Young-Shin LEE) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4

For the Space-borne optical imaging payload system design, light weighting and moderate stiffness of mirror andor mirror fixation device is very important aspects. The front surface of mirror is regulated by optical performance requirement, but the shape of backplate of mirror is to be optimised while satisting the required stiffness and weight. According to the results, the best shape of backplate cell is triangular. And also related geometric dimensions and the optimised mounting point of MFD(Mirror Fixation device)is presented. Finally, matural frequencies and mode shapes of mirror stucture are analysed.

적외선 및 가시광선 결상용 3반사망원경계의 설계

이종웅,홍경희,권우근 한국광학회 1996 한국광학회지 Vol.7 No.3

적외선, 가시광선 겸용의 3반사망원경계를 설계하기 위하여 형상설계법 및 3차수차의 보정방법이 연구되었다. 적외선용의 광학계는 3반사경계만으로 구성되었으며 원추곡면화를 통하여 구면수차, 코마, 비점수차를 보정하였다. 가시광선용의 광학계는 적외선용의 3반사경계의 상면앞에 보정렌즈를 추가하여 상면만곡을 보정하였다. 설계된 3반사망원경계는 파장 10.mu.m에서는 시계 2.4.deg. 내에서 회절한계의 결상성능을 가지고 있다. 가싣광선대역의 단파장에 대한 rms spot size는 3.deg. 시계내에서 25.mu.m이하이며, CCD의 사용에 적합하도록 flat field 조건을 만족하고 있다. To design three-mirror telescope system (F/8, 120 inch in focal length) for visible and infra-red band imaging, methods for power configuring and correction of the third order aberrations were studied. In the design of the telescope system, a three-mirror system corrected for spherical aberration, coma, and astigmatism was used for infra-red imaging, and the aberrations were corrected by using conic surfaces. For visible imaging, a singlet corrector lens was appended at the front of the focal plane to correct filed curvature. The telescope system has diffraction limited performance for 10 ${\mu}{\textrm}{m}$ in wavelength within 2.4$^{\circ}$ of field-of-view. In the visible band imaging, the rms spot size of the telescope system is less than 25 ${\mu}{\textrm}{m}$ within 3$^{\circ}$ of field-of-view for monochromatic light, and the telescope system satisfies flat field condition for CCD application.

3종의 3차수차가 보정된 3구면경계

오승경,이종웅,권우근,홍경희 한국광학회 1995 한국광학회지 Vol.6 No.2

3구면경계에서 aplanat 조건을 해석적으로 유도하고 이를 바탕으로 3종의 3차수차가 보정된 3구면 경계의 형태 및 존재영역을 조사하였다. 실상을 맺으면서 aplanat 저건을 만족하는 3구면경계는 유효초점거리가 양수인 경우 PPN, NPP, PNP 형태의 해가 존재하였으며 N은 볼록 거울, P는 오목 거울을 나타낸다. 유효초점거리가 음수인 경우 NPN, NPP, PNP, NNP형의 4종류의 형태가 존재하였다. 3종의 3차수차가 보정된 3구면경계에서 astigmatic aplanat는 실상을 맺는 해가 존재하지 않았다. Flat field aplanat는 PPN, PNP, NPP형태의 해가 존재하였고 distortion free aplanat의 경우는 PPN, PNP, NPN, NPP, NNP형의 해가 존재하였다.

Current Knowledge and Future Therapeutic Prospects in Symptomatic Intervertebral Disc Degeneration

김주한,함창화,권우근 연세대학교의과대학 2022 Yonsei medical journal Vol.63 No.3

Intervertebral disc (IVD) degeneration is the main source of intractable lower back pain, and symptomatic IVD degenerationcould be due to different degeneration mechanisms. In this article, we describe the molecular basis of symptomatic IVD degenerativedisc diseases (DDDs), emphasizing the role of degeneration, inflammation, angiogenesis, and extracellular matrix (ECM)regulation during this process. In symptomatic DDD, pro-inflammatory mediators modulate catabolic reactions, resulting inchanges in ECM homeostasis and, finally, neural/vascular ingrowth-related chronic intractable discogenic pain. In ECM homeostasis,anabolic protein-regulating genes show reduced expression and changes in ECM production, while matrix metalloproteinasegene expression increases and results in aggressive ECM degradation. The resultant loss of normal IVD viscoelasticity and a concomitantchange in ECM composition are key mechanisms in DDDs. During inflammation, a macrophage-related cascade is representedby the secretion of high levels of pro-inflammatory cytokines, which induce inflammation. Aberrant angiogenesis is considereda key initiative pathologic step in symptomatic DDD. In reflection of angiogenesis, vascular endothelial growth factorexpression is regulated by hypoxia-inducible factor-1 in the hypoxic conditions of IVDs. Furthermore, IVD cells undergoing degenerationpotentially enhance neovascularization by secreting large amounts of angiogenic cytokines, which penetrate the IVD fromthe outer annulus fibrosus, extending deep into the outer part of the nucleus pulposus. Based on current knowledge, a multi-disciplinaryapproach is needed in all aspects of spinal research, starting from basic research to clinical applications, as this will provideinformation regarding treatments for DDDs and discogenic pain.

두개인두종으로 오인된 라스케씨 열낭종: 내시경적 비강내 접근법을 통한 수술 경험

이동한,노해원,조현준,권우근,윤원기,김종현,권택현,변준호 대한두개저학회 2024 대한두개저학회지 Vol.19 No.1

Rathke’s cleft cysts (RCCs) are non-neoplastic cysts originating from Rathke’s pouch remnants. This case report presents a unique case of a suprasellar RCC that closely resembles craniopharyngioma, highlighting the diagnostic difficulty involved. A 51-year-old female patient presented with headaches and visual disturbances, and magnetic resonance imaging revealed two cystic masses around the pituitary stalk. Initially suspected as craniopharyngioma, surgical intervention revealed RCC based on histopathological examination. The report emphasizes the importance of differentiating RCC from other parasellar cystic masses, especially craniopharyngioma, and discussing key diagnostic factors.

적외선 열 영상장비의 기본원리 및 기술동향

홍석민(S.M Hong),송인섭(I.S. Song),권우근(W.K. Kwon),김재기(J.K. Kim) 대한전기학회 1992 대한전기학회 학술대회 논문집 Vol.1992 No.7