광대역 파장가변 이중 링 공진기 Add/Drop 필터

이동현,이태형,박준오,김수현,정영철,Lee, Dong-Hyun,Lee, Tae-Hyung,Park, Joon-Oh,Kim, Su-Hyun,Chung, Young-Chul 한국광학회 2007 한국광학회지 Vol.18 No.3

본 논문에서는 굴절률 차이가 큰 폴리머 광 도파로를 이용하여 광대역 파장가변이 가능한 이중 링 공진기 Add/Drop 필터를 제작하였다. Add/Drop 필터의 제작시 공정 오차에 둔감한 특성을 갖도록 광 결합기를 설계하였다. 코어와 클래딩의 굴절률은 1550 nm 파장 대역에서 각각 1.51, 1.378로 약 $100{\mu}m$ 정도의 곡률 반경을 가지는 곡선 도파로를 수용할 수 있다. 두 개의 링이 동시에 공진하는 파장 대역에서 Drop 특성은 이웃하는 피크 좌다 약 2.9 dB 이상 높은 특성을 보였다. 이 필터는 반사형 반도체 광증폭기 등과의 하이브리드 집적을 통하여 광대역 파장 가변 레이저 다이오드를 구현하는데 활용할 수 있을 것으로 기대된다. A widely tunable add/drop filter composed of double ring resonators is implemented with high-index-contrast polymer waveguide. To enhance the productivity, directional couplers are designed to have good fabrication tolerance. The refractive indices of the core and cladding in the 1550 nm wavelength are 1.51 and 1.378, respectively. Drop response in comparison with neighborhood peak gets enhanced by more than 2.9 dB at the wavelength where both rings resonate. This filter can be used to build widely tunable laser diode through hybrid-integration with reflective SOA.

소결 온도에 따른 0.98(Na_0.5K_0.5)NbO₃-0.02Li(Sb_0.17Ta_0.83)O₃+0.01wt%ZnO 세라믹스의 압전 특성

이동현,이승환,이성갑,이규탁,이영희,Lee, Dong-Hyun,Lee, Seung-Hwan,Lee, Sung-Gap,Lee, Ku-Tak,Lee, Young-Hie 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.7

We studied sintering temperature to enhance the piezoelectric properties of $0.98(Na_{0.5}K_{0.5})NbO_3-0.02Li(Sb_{0.17}Ta_{0.83})O_3$+0.01wt%ZnO (hereafter NKN-LST+ZnO) lead free piezoelectric ceramics. The synthesis and sintering method were the conventional solid state reaction method and sintering was executed at $1,080\sim1,120^{\circ}C$. We found that NKN-LST+ZnO ceramics at optimal sintering temperature showed the improved piezoelectric properties at the optimal sintering temperature. The NKN-LST+ZnO ceramics show good performance with piezoelectric constant $d_{33}$= 153 pC/N sintered at $1,090^{\circ}C$. The results reveal that NKN-LST+ZnO ceramics are promising candidate materials for lead-free piezoelectric application.

하악 전돌증 환자에서 전산화 단층 촬영을 이용한 하악관의 해부학적 위치에 관한 연구

이동현,김재원,이수연,김재현,안상헌,이상한,장현중,Lee, Dong-Hyun,Kim, Jae-Won,Lee, Su-Youn,Kim, Jae-Hyun,An, Sang-Heon,Lee, Sang-Han,Jang, Hyun-Jung 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.6

Purpose: In this study, we analyzed and compared the anatomical position of the mandibular canal in normal occlusion and mandibular prognathism patients. Patients and Methods: Computed tomography image from 58 patients were divided into normal occlusion group and mandibular prognathism group, and each measurement were taken in the each measuring points(2nd premolar, 1st molar, 2nd molar, 3rd molar, ramus). Measurements were statistically analyzed by student's t-test. Results: BC (Thickness of the buccal cortex) value was 2.3~2.7 mm, CB (Distance from the canal to the lingual aspect of the buccal cortex) value was 1.3~4.3 mm, MC (Diameter of the canal) value was 3.2~3.8 mm, LI (Distance from the canal to the lingual aspect of the lingual cortex) value was 2.0~3.7 mm, TM (Thickness of the total mandible) value was 9.5~12.9 mm and CM (Distance from the canal to the inferior border of the mandible) value was 6.9~17.5 mm. Conclusion: In the comparison between two groups, there was statistically significant difference in CB value of 2nd, 3rd molar between normal occlusion and mandibular prognathism, and other value in the rest of the measuring points didn't show statistically significant difference.

대학 공시정보를 활용한 교육국제화역량 인증 여부 예측: 이산선택모형에 의한 대학알리미 공시정보 분석

이동현(Lee, Dong-hyun),조순정(Cho, Soon-jeong) 한국경영교육학회 2020 경영교육연구 Vol.35 No.3

[연구목적] 본 연구는 대학 공시정보를 활용하여 교육국제화역량 인증(IEQAS) 여부를 예측하며, 대학의 인증 유지를 위한 자가 점검에 적합한지 연구 모형을 검증하는데 목적이 있다. [연구방법] 동 연구는 IEQAS 인증․미인증 예측을 위해 2019년 대학알리미 웹사이트에 공개된 138개 사립 대학의 공시정보를 수집했다. 이어, 인증 대학 77개교 및 미인증 대학 61개교 두 집단 간 지표 차이를 검정 후, 5개의 대학경쟁력지표 및 9개의 재정회계지표를 독립 변수로, 2019년 3월에 발표된 IEQAS 인증 결과를 이산형 종속 변수로 설정하여 이산선택모형에 따라 로짓분석과 판별분석을 하였다. [연구결과] 본 연구자들은 t-검정으로 선별한 재학생충원율/신입생충원율/전임교원확보율(이상 대학경쟁력), 학생1인당교육비/교육비환원율/부채비율/법인전임급비율(이상 재정회계)을 연구 모형에 유의한 요인으로 투입했다. 그 결과, 대학경쟁력 지표를 통한 예측력은 로짓분석 71.7%, 판별분석 71.0%로, 재정회계 지표의 경우 로짓분석 70.3%, 판별분석 66.7%의 예측력을 보였다. 동 이산선택모형 내에 공통으로 관여한 유의미한 변수는 재학생충원율, 신입생충원율과 학생1인당교육비로 나타났다. [연구의 시사점] 동 연구는 조직의 부실 여부 예측에 유용한 로짓분석과 판별분석을, 정부의 대학별 공개 자료를 활용하여 IEQAS 인증․미인증 예측에 적용해 본 가치를 지닌다. 본 연구의 이산선택모형은 타당성과 신뢰성이 확인됨으로써, 대학이 손수 IEQAS 인증 유지 점검 시 활용할 수 있으며 대학 평가에 관한 경영교육 실무에 기여할 것이다. [Purpose] Based on a discrete choice model(DCM), this study aims to predict the ‘pass/fail’ of the International Education Quality Assurance (IEQAS) by analyzing publicly opened dataset. Thus, it will enable Korean universities to self-test their IEQAS-related capabilities in a productive manner. [Methodology] This work utilized disclosed data on academyinfo.go.kr in 2019, including a total of 138 private universities from My university competitiveness(MUC), Financial accounting index(FAI); relying on related literature, it proposed two hypotheses and 14 independent variables, followed by conducting logit analysis(LA) and discriminant analysis(DA). [Findings] First, t-tests identified three MUC variables(Levy with enrolled students; Levy with new students; Faculty in full service) and four FAI variables(Educational expenditure; Educational restitution rate; Liability ratio; Corporate transferred money) between 77 IEQAS ‘pass’ group and 61 IEQAS ‘fail’ group in 2019. This DCM presented the following predictive powers: 71.7%-LA vs 71.0%-DA in MUC and 70.3% -LA vs 66.7%-DA in FAI, while Levy with enrolled students, Levy with new students and Educational expenditure worked as keys to predicting the ‘pass/fail’. [Implications] The DCM combining LA/DA can be used for both scholars on the business education area and the IEQAS-related practitioners.

신경외과 수술로 인한 신경영양각막염 환자에서 동일초점현미경을 이용한 각막미세구조 변화 분석

이동현*,최은영*,김응권,이형근,Dong Hyun Lee*,Eun Young Choi*,Eung Kweon Kim,Hyung Keun Lee 대한안과학회 2014 대한안과학회지 Vol.55 No.12

Purpose: To investigate the changes of the corneal microstructure of neurosurgically-induced neurotrophic keratitis patients compared to normal human corneas using in vivo confocal microscope (IVCM). Methods: Ten eyes in the normal control group and 11 eyes in the neurosurgically-induced neurotrophic keratitis patient group were included in the present study. After corneal sensitivity tests were performed, thickness of each layer and number of endothelial cells and stromal keratocytes in the cornea were assessed using IVCM. Morphological characteristics of the corneal nerves were measured by ImageJ software. Results: After analysis of corneal thickness layer by layer, the Bowman’s layer was significantly reduced in the neurosurgicallyinduced neurotrophic keratitis patient group compared with the normal control group (<EM>p</EM> = 0.016) and the portion of Bowman’s layer was significantly reduced in the neurosurgically-induced neurotrophic keratitis patient group compared with the control group (<EM>p</EM> = 0.024). The nerve fiber length per square-millimeter became significantly shorter compared to the normal control group (<EM>p </EM>= 0.042). The nerve fiber length per square millimeter showed significant correlations with the number of fibers, number of beading, branching patterns, and nerve tortuosity (<EM>p</EM> = 0.002, 0.002, 0.013 and 0.034, respectively). The number of endothelial cells and stromal keratocytes, the number of nerve fibers and beading, and the pattern of branching and nerve tortuosity showed no significant differences between the normal and neurosurgically-induced neurotrophic keratitis patient groups. Conclusions: Our results showed that decreased thickness of Bowman’s layer may be related to the decreased corneal nerve distribution, secondary to the dysfunction of trigeminal nerve branch innervating the cornea. The microstructural changes of Bowman’s layer can help diagnose the disease and evaluate the current status in neurosurgically-induced neurotrophic keratitis patients. J Korean Ophthalmol Soc 2014;55(12):1765-1771

뇌경색환자 치험 1례를 통한 오행침(五行鍼)과 육기침(六氣鍼)의 연구

이동현,정영표,정효근,이은방,류충열,조명래,채우석,나건호,Lee, Dong-Hyun,Jeong, Yeong-Pyo,Jeong, Hyo-Keun,Lee, Eun-Bang,Ryu, Chung-Ryul,Cho, Myung-Rae,Chae, Woo-Seok,Na, Gun-Ho 대한동의생리학회 2006 동의생리병리학회지 Vol.20 No.6

The purpose of this case is to report the improvement after treatment about a patient with cerebral infarction by Sa-Am's Ohaeng-acupuncture and Liuqi-acupuncture. We treated the patient with acupuncture therapy from 6th September 2004 to 15th November 2004 Dy reinforcing Dadun(LR 1)Zusan Li(5736) Quchi(Li 11) and reducing Taibai(Sp 3) on the basis of etiological analysis and differentiation of endogenous wind caused by damp phlegm and heat. Right hemiplegia improved Gr. 1 to Gr. tV after acupuncture therapy. We interpreted 'reinforcing Dadun(LR 1) and reducing TaiDai(SP 3)'as using Simjeonggyeok in conjunction with Simseunggyeok on the basis of Sa-Am's Ohaeng-acupuncture. We interpreted 'reinforcing Dadun(LR 1) and reducing Taibai(Sp 3)' as excreting dampness in Spleen on the basis of Liuqi-acupuncture. We interpreted 'reinforcing Zusan Li(57 36) and Quchi(Li 11)' as eliminating wind-dampness and menstrual regulation.

심층 컨벌루션 신경망 기반의 실시간 드론 탐지 알고리즘

이동현,Lee, Dong-Hyun 한국로봇학회 2017 로봇학회 논문지 Vol.12 No.4

As drones gain more popularity these days, drone detection becomes more important part of the drone systems for safety, privacy, crime prevention and etc. However, existing drone detection systems are expensive and heavy so that they are only suitable for industrial or military purpose. This paper proposes a novel approach for training Convolutional Neural Networks to detect drones from images that can be used in embedded systems. Unlike previous works that consider the class probability of the image areas where the class object exists, the proposed approach takes account of all areas in the image for robust classification and object detection. Moreover, a novel loss function is proposed for the CNN to learn more effectively from limited amount of training data. The experimental results with various drone images show that the proposed approach performs efficiently in real drone detection scenarios.

임플란트 증례에서 발생하는 심미적 문제점들에 관한 고찰

이동현,Lee, Dong-Hyun 대한심미치과학회 2015 Journal of the Korean Academy of Esthetic Dentistr Vol.24 No.1

전치부 임플란트의 심미성에 영향을 미치는 중요한 요소는 다음과 같다. 1) 임플란트 식립체의 올바른 위치, 2) 치조골의 충분한 양, 3) 연조직의 최적의 양. 임플란트 위치는 심미적인 치료결과를 얻는 데에 가장 중요한 요소일 것이다. 임플란트의 3차원적 위치는 치조제의 위치와 방향에 의해 결정된다. 임상가들은 수복물을 제작할 때 흔히 자연치를 모방하려 한다. 그러나 심미적인 진단 및 치료를 하는 과정에서 잊지 말아야 할 것은 얼굴형태, 입술, 치은, 치조제, 그리고 잔존치아들과의 상관관계를 고려하는 것이다. 전치부는 구치부에 비해 생물학적으로 불리하며, 조금이라도 임플란트 위치가 틀어지면 심미적으로 좋지 않은 결과를 야기할 수 있다. 임플란트 3치원적 위치의 생물학적, 보철적 의미를 이해한다면, 전치부에 더욱 심미적인 결과를 얻을 수 있을 것이다. The critical factors affecting the esthetics of anterior implants can be summarized as following: 1) Correct positioning of implant fixture, 2) Enough amount of alveolar bone, 3) Optimum volume of soft tissue. The position of implant is probably the most important factor in obtaining esthetic treatment outcome. The 3-dimensional orientation of implant is determined by the position on the alveolar ridge and its direction. Clinicians often try to mimic natural teeth when fabricating restorations. During the course of esthetic diagnosis and treatment, however, one should not forget to consider the correlation between facial pattern, lips, gingiva, alveolar ridge, as well as remaining dentition. Since anterior region is biologically unfavorable when compared with posterior region, one minor discrepancy in positioning of implant can cause esthetically undesirable treatment outcome. If one understands the biological and prosthetic meaning of implant' s 3-dimensional position, he or she can achieve superior esthetic outcome in anterior region.

성장장애(成長障碍)를 주소(主訴)로 내원(來院)한 환아(患兒)의 치료(治療) 효과(效果)에 대한 고찰(考察)

이동현,김덕곤,Lee Dong-Hyun,Kim Duck-Gon 대한한방소아과학회 1998 대한한방소아과학회지 Vol.12 No.1

The purpose of this study was to determine the effects of oriental medical care on growth deficiency children. These cases were collected to investigate the effects of oriental medical care on growth deficiency children. So the cases were divided into 5 groups. The growth velocity was compared to a normal growth curve, and the results are as follows: 1. Oriental medical care was efficient when the epiphysial plates were not closed. 2. In female middle school beyond 1st grade students and in male middle school 3rd grade students who had almost closed epiphysial plates, the oriental medical care was not efficient and did not promote growth velocity. endothelium were used for the experiment using organ bath. 3. In the cases where the parent were very short, the effects of the oriental medical care to promote growth velocity was not efficient. 4. when we treated children of normal height, their growth velocity was over the normal growth curve. 5. In preschool aged children, oriental medical care was very efficient to promote children's growth. 6. The principle oriental medical care was to make balanced their body and digestive organs by using herb medicines that have the capability to promote the growth of the bones, and build strong muscles.

장액망막박리가 동반된 레버 특발성 성상 신경망막염에서 안내 베바시주맙 주사 효과 1예

이동현,고형준,김성수,이성철,김민,Dong Hyun Lee,Hyoung Jun Koh,Sung Soo Kim,Sung Chul Lee,Min Kim 대한안과학회 2014 대한안과학회지 Vol.55 No.10

Purpose: To report the effectiveness of intravitreal bevacizumab treatment for serous retinal detachment associated with Leber’s idiopathic stellate neuroretinitis. Case summary: A 56-year-old male visited our clinic complaining of visual disturbance for three days in his right eye. His best corrected visual acuity was 0.5. Relative afferent pupillary defect and pain when moving eyes were noted in his right eye as well as inflammatory cells in the vitreous cavity. On funduscopic examination, disc swelling with hemorrhage and stellate-shaped hard exudates were noted at the perifovea. Ishihara color vision test showed anomalous trichromacy in his right eye. Hyperfluorescence around the disc was observed on fundus fluorescein angiography. Optical coherence tomography showed disc swelling with serous retinal detachment at the fovea. Inferior altitudinal scotoma was noted on visual field examination. The patient underwent intravitreal bevacizumab injection and topical steroid medication. After six days, the patient’s symptoms and disc swelling improved, and decreased subretinal fluid was observed. After six weeks, his best corrected visual acuity was 1.0. Nine weeks later, visual field examination showed nonspecific scotoma. Conclusions: Intravitreal bevacizumab injection is useful for treating serous retinal detachment associated with Leber’s idiopathic stellate neuroretinitis. J Korean Ophthalmol Soc 2014;55(10):1562-1566