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.

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.

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.

요통(腰痛) 및 요각통(腰脚痛) 환자에 있어 약침치료(藥鍼治療)의 호전도에 대한 임상적 고찰

이동현,김효수,위통순,Lee, Dong-Hyun,Kim, Hyo-Soo,Wei, Tung-Shuen 대한약침학회 2004 Journal of pharmacopuncture Vol.7 No.2

Objectives : The purpose of this study is to compare the improvement rate in managering patients who had lumbago and pain in loin & feet by herbal-acupunture therapy with conservative treatment. Methods : 40patients who invited from March. 2003 to May. 2004 with lumbago and pain in loin & feet inve, were divided into two classes. A class was managed with conservative treatment(acupuncture, herb med, negative therapy, bed rest and physical therapy) and herbal-acupuncture therapy, the other class was managed with conservative treatment only. Two classes were distributed by sex and age, therapeutic periods, radiolographic results and therapeutic results that checked with VAS(visual analog scale) and ODI(Oswestry disability index). Results : According to VAS and OBI results, A class was managed with conservative treatment and herbal-acupuncture therapy shows the improvement in controling the pain of lumbago etc. comparing with the other class.

4원법과 유한요소를 이용한 유연체 동역학의 해석기법

이동현,윤성호,Lee, Dong-Hyun,Yun, Seong-Ho 한국전산구조공학회 2005 한국전산구조공학회논문집 Vol.18 No.2

본 논문에서는 유연체 동역학해석을 위하여 유한회전을 표현하는데 있어, 4원법의 대수학적인 표현을 도입하여 운동방정식이 에너지보존 조건을 만족하도록 이산화된 에너지 평형식으로 정식화되었다. 여기서 사용된 유한회전의 4원법은 로드리게스 매개변수를 이용하도록 하였으며, 구속력에 대한 일이 제거되도록 하였다. 수치해석의 예를 통하여 제안된 방법이 사다리꼴 방법과 비교할 때 비선형 문제에서도 무조건적으로 안정조건을 보장함을 검증하였으며, 향후 유연한 관절로 연결된 3차원 유연다물체에 대한 동역학 해석을 확장할 수 있는 토대를 마련하였다. This paper deals with formulations of the energy equilibrium equation by an introduction of the algebraic description, quarternion, which meets conservations of system energy for the equation of motion. Then the equation is discretized to analyze the dynamits analysis of flexible multibody systems in such a way that the work done by the constrained force completely is eliminated. Meanwhile, Rodrigues parameters we used to express the finite rotation lot the proposed method. This method lot the initial essential step to a guarantee of developments of the 3D dynamical problem provides unconditionally stable conditions for the nonlinear problems through the numerical examples.

근시 환자의 임상진료 시 초광각 주사레이저검안경으로 발견 가능한 주변부 망막 소견 및 유용성

이동현,김성수,김민,고형준,Dong Hyun Lee,Sung Soo Kim,Min Kim,Hyoung Jun Koh 대한안과학회 2014 대한안과학회지 Vol.55 No.12

Purpose: To investigate identifiable peripheral retinal lesions in patients with myopia or high myopia and to evaluate the usefulness of ultra-widefield scanning laser ophthalmoscope in retina clinic settings. Methods: We evaluated fundus images of 149 patients acquired using an ultra-widefield scanning laser ophthalmoscope. Manual fundus examination by a retinal specialist was performed and sensitivity and specificity were calculated by comparing the findings of the two different fundus examination methods. Results: Variable peripheral retinal lesions were observed: lattice degeneration (24.1% in myopia, 36.6% in high myopia), white without pressure (17.7% in myopia, 20.7% in high myopia), retinal break (5.1% in myopia, 7.5% in high myopia) and retinal detachment (1.3% in myopia, 4.2% in high myopia). The incidence of lattice degeneration was significantly higher in myopic eyes than in highly myopic eyes (<EM>p</EM> = 0.043). The examination sensitivities were as follows: lattice degeneration (84.2% in myopia, 91.0% in high myopia), white without pressure (100.0% in both myopia and high myopia), retinal break (75.0% in myopia, 43.8% in high myopia) and retinal detachment (100.0% in myopia, 66.7% in high myopia). The examination specificities were 100.0% in all cases. Conclusions: Diagnostic sensitivities of ultra-widefield scanning laser ophthalmoscope were 90.8% in patients with myopia, 91.0% in patients with high myopia and 90.9% in totally myopic patients, which were relatively high values. Therefore, the ultra- widefield scanning laser ophthalmoscope is useful as auxiliary equipment for myopic patients in retina clinic settings. J Korean Ophthalmol Soc 2014;55(12):1814-1820

오행침(五行鍼)과 육기침(六氣鍼)을 응용한 뇌경색환자 치험 1례

이동현,정영표,김현수,류충열,조명래,채우석,나건호,Lee, Dong-Hyun,Jeong, Yeong-Hyo,Kim, Hyeon-Hu,Ryu, Chung-Ryul,Cho, Myeong-Rae,Chae, Woo-Seok,Na, Gun-Ho 경락경혈학회 2006 Korean Journal of Acupuncture Vol.23 No.1

Objectives : 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. Methods : We treated the patient with acupuncture therapy from 6th September 2004 to 15th November 2004 by reinforcing Dadun(Liv 1) Zusan Li(S36) Quchi(Li 11) and reducing Taibai(Sp 3) on the basis of Etiological Analysis and Differenciation of Endogenous Wind caused by Damp Phlegm and heat. Results .1. Right hemiplegia improved Gr. I to Gr.IV after acupuncture therapy. 2. we interpreted 'reinforcing Dadun(Liv 1) and reducing Taibai(SP 3)'as using Simjeonggyeok in conjunction with Simseunggyeok on the basis of Sa-Am's Ohaeng-acupuncture. 3. we interpreted 'reinforcing Dadun(Liv 1) and reducing Taibai(Sp 3)'as Excreting Dampness in Spleen on the basis of Liuqi-acupuncture. 4. we interpreted 'reinforcing Zusan Li(S 36) and Quchi(Li 11)'as Eliminating Wind-dampness and Menstrual Regulation.

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

주파수 가변 및 소형 Metamaterial Peano Antenna

이동현,장경덕,박위상,Lee, Dong-Hyun,Jang, Kyung-Duk,Park, Wee-Sang 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.8

본 논문에서는 Peano curve의 가장자리에 인덕터를 집적한 주파수 가변 소형 metamaterial 안테나를 제안하였다. 제안된 안테나는 1차 Peano curve 평면과 그라운드 평면으로 구성되며, 이 두 평면은 두 개의 단락 post로 연결되어 있다. 이 단락 post와 Peano curve 사이에는 인덕터가 부착되어 있다. 두 인덕터의 inductance를 적절히 선택하여 입력 임피던스 대역폭의 감소 없이 안테나의 동작 주파수를 조절할 수 있다. 안테나의 동작 원리를 설명하기 위해 안테나의 등가 회로를 제시했다. 시뮬레이션 결과를 검증하기 위해 몇 가지 다른 인덕터가 부착된 안테나를 제작했으며, 측정 결과는 시뮬레이션 결과와 매우 잘 일치한다. 인턱터 값 조합에 따라 입력 임피던스의 감소 없이 동작 주파수가 1.47 GHz에서 0.586 GHz로 변함이 측정되었다. 91 nH와 470 nH의 두 인덕터를 집적한 경우, 안테나의 전기적 크기는 $0.0246 {\lambda}{\times}0.0246{\lambda}{\times}0.0114{\lambda}$로 매우 소형이다. 이 때 측정된 입력 임피던스 대역폭$(S_{11}{\leq}-10 dB)$과 방사 효율은 각각 5.22 %와 47.25 %이다. In this paper, we present a frequency tunable and compact antenna which consists of a first-order Peano curve, two shorting posts, and two inductors which are serially connected between the posts and the edge of the Peano curve. By properly choosing the inductance of two inductors, the operating frequency of the antenna can be controlled without sacrificing the fractional bandwidth. To give good demonstration of the operating mechanism, the equivalent circuit of this antenna is included. To validate the simulation results, we have fabricated the several antennas of being integrated with different inductors, and the measured results show a good agreement with the simulated ones. The measured results reveal that the operating frequency is shifted from 1.47 GHz to 0.586 GHz without the decrease of the input impedance bandwidth. In case of integrating two inductors of 91nH and 470nH, the electric size of the antenna is only $0.0246 {\lambda}{\times}0.0246{\lambda}{\times}0.0114{\lambda}$. The measured fractional bandwidth$(S_{11}{\leq}-10 dB)$ and the radiation efficiency of the antenna are 5.22% and 47.25%, respectively.