스펙트럼 도메인 빛간섭단층촬영에서 발생하는 오류

김형준,정혜원,김형찬,Hyung Jun Kim,Hyewon Chung,Hyung Chan Kim 대한안과학회 2011 대한안과학회지 Vol.52 No.8

Purpose: To report frequencies of image artifacts associated with spectral-domain optical coherence tomography (SD-OCT) and to evaluate the impact of artifacts on foveal thickness measurements. Methods: This retrospective study included 267 eyes of 267 patients who underwent OCT volume scanning using Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany). Macular volume scans of normal and diseased eyes were systematically evaluated for image artifacts within each scan overall and within the center 1-mm area. The frequency of each artifact type was compared for scans stratified by diagnosis category. Results: Among the volume scans, 79.4% had at least 1 artifact overall, and 26.6% had at least 1 artifact in the center 1-mm area. The highest percentage of inner retina misidentification occurred in the epiretinal membrane (36.1%), whereas the highest percentage of outer retina misidentification occurred in neovascular age-related macular degeneration (wet AMD, 40.0%). Clinically significant artifacts involving the center 1-mm area were observed in 6.4% of volume scans and were most common in wet AMD (43.3%). Conclusions: Image artifacts in SD-OCT volume scanning are common, but relatively less common in the center 1-mm area of scans. Clinicians should carefully review scans for artifacts when using SD-OCT images and retinal thickness measurements because clinically significant artifacts may affect retinal thickness measurements. J Korean Ophthalmol Soc 2011;52(8):943-951

인공지능 기반 가상 비서의 BIM 설계 적용에 관한 기초연구

김형준(Kim, Hyung?Jun),전한종(Jun, Han-Jong) 대한건축학회 2018 대한건축학회 학술발표대회 논문집 Vol.38 No.1

In this research, in order to solve the problem of degradation of business efficiency of building design utilizing BIM, a process was constructed using virtual assistant based on artificial intelligence technology. In the constructed process, the designer can learn the command customized to the virtual assistant applied to the BIM architecture design work, using the A-BIM algorithm. These A-BIM algorithms are utilized in the form of artificial intelligence algorithms built in the understanding structure of the designer. As a result, it is expected that the efficiency of operations can be improved by fusing the conventional artificial intelligence technology and the A-BIM algorithm, rather than developing artificial intelligence to be applied to the field of BIM architectural design.

진공 하에서 전기방사된 부직포의 특성에 대한 연구

김형준,정윤호,길명섭,김학용,방호주,Kim Hyung-jun,Jung Yoon-ho,Khil Myung-seob,Kim Hak-yong,Bang Ho-Ju 한국섬유공학회 2004 한국섬유공학회지 Vol.41 No.6

The exploitation of technologies based on electro spinning have been limited due to poor understanding of the process and consequent limitation in process control, productivity and reproducibility. To control the effect of the environmental parameter, which is one of important electro spinning parameters, the vacuum process was introduced because the magnitude of electric field in vacuum is not limited by the low dielectric breakdown strength of air. For this study, PCL dissolved in a mixture of N,N-dimethylformamide (DMF) and methylene chloride (MC) was electrospun as a form of nonwoven mats consisting of nano-sized fibers under vacuum and they have been analyzed using SEM and DSC. The PCL nonwoven mats via electrospinning under vacuum showed the characteristic spinning behavior observed at atmospheric pressure. In addition, results obtained from tensile test showed that PCL nonwoven mats via electro­spinning under vacuum have better mechanical properties than those prepared at atmospheric pressure.

파이로테크닉 고섬광 발생장치 조성설계 및 설계검증

김형준,최성욱,권미라,황준식,장쾌현,Kim, Hyung Jun,Choi, Sung Wook,Kwon, Mi Ra,Hwang, Jun Sik,Chang, Kwe Hyun 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.3

The composition of bright flash device is a pyrotechnic mixture consisting of metal powder, oxidizer and additives. A pyrotechnic mixture of bright flash device generates a bright flash through burning after being ignited by initiator. The function of bright flash is to distract or incapacitate electro optical sensor systems and enemy eyes temporally. This study is to develop composition of pyrotechnic mixture of bright flash and to analyze the test results by considering intensity and efficiency of light.

Torulopsis bombicola 에 의해 생산된 생계면활성제의 특성에 관한 연구

김형준,류정용,박돈희 ( Hyung Jun Kim,Jeong Yong Ryu,Don Hee Park ) 한국화학공학회 1995 화학공학의이론과응용 Vol.1 No.2

진당원(珍糖元)의 고혈당 조절 작용 및 기전에 관한 연구

김형준,윤철호,정지천,Kim, Hyung-Jun,Yoon, Cheol-Ho,Jeong, Ji-Cheon 대한한방내과학회 2004 大韓韓方內科學會誌 Vol.25 No.2

Objective : Diabetes is a disease in which the body does not produce or properly use insulin. Etiological studies of diabetes and its complications showed that oxidative stress might playa major role. Therefore, many efforts have been made to regulate oxygen free radicals for treating diabetes and its complications. Because Jindangwon has been known to be effective in treatment of diabetes, the methanol extract of Jindangwon was tested for its effectiveness in reducing the oxidative stress induced by Streptozotocin. Methods : Jindangwon was washed, dried in the shade and crushed. The crushed Jindangwon was extracted 3 times, each time with 3 volumes of methyl alcohol at $60^{\circ}C$ for 24 hours. The extract was filtered and evaporated under reduced pressure using a rotary evaporator to yield 30.6 g. Jindangwon extract was oral-administered to the diabetic rats induced by streptozotocin 50 mg per 1 kg of body weight for 15 days. The efficacy of the Jindangwon extract was examined with regard to the enzymatic pathways involved in the oxygen free radical production and the glutathione balance. Results : he effects of the methanol extract of Jindangwon in streptozotocin-induced diabetics rats with regard to body weight, blood glucose level, hepatic lipid peroxide level, hepatic xanthine oxidase activity and type conversion rate, hepatic glutathione level, hepatic glutathione peroxidase activity, hepatic glutathione reductase activity, hepatic aldose reductase activity, and hepatic sorbitol dehydrogenase activity were favorable enough to suggest that it is a cure for diabetes and its complications. Conclusions :These results support Jindangwon as an effective reducing agent for oxidative stress in the tissues and organs by regulating the production of oxygen free radicals. Jindangwon, in particular, shows promising results for its use as a cure, or preventative medicine for diabetes and its complications by reducing oxidative stress in beta-cells of the pancreas.

이민기와 플루오렌기를 주쇄에 함유하는 고분자의 광기전 성질

김형준,이정효,곽찬규,진성호,이택승,Kim, Hyung-Jun,Lee, Jung-Hyo,Kwak, Chan-Kyu,Jin, Sung-Ho,Lee, Taek-Seung 한국섬유공학회 2008 한국섬유공학회지 Vol.45 No.1

New polyimine derivative containing fluorene group in the main chain was synthesized via Suzuki cross-coupling polymerization, reduction, and imine formation reaction, consecutively. The synthesized polymer was characterized and explored as organic photovoltaic cell device. The imine polymer P3 in diluted chloroform solution emitted red light (582 nm), whereas its precursor polymers P1 and P2 showed green (about 530 nm) and blue fluorescence (477 nm), respectively. Bulk heterojunction photovoltaic cells fabricated by blending P3 with the fullerene derivative PCBM was found to have a power conversion efficiency of upto 0.0005%, while cells from blending P3 with MEH-PPV yielded 0.0008% of power conversion efficiency.

강변저류지에 의한 홍수저감 효과 분석을 위한 수리실험

김형준,배덕원,윤광석,Kim,Hyung-Jun,Bae,Deok-Won,Yoon,Kwang-Seok 한국방재학회 2011 한국방재학회논문집 Vol.11 No.6

강변저류지는 홍수저감효과 뿐만 아니라 생태적인 목적으로도 활용이 가능하여 최근 강변저류지 설치에 관한 연구가 활발히 진행되고 있는 상황이다. 그러나, 강변저류지 설치에 따른 홍수저감효과는 기존에 개발된 수치모형에 의존하고 있으며, 수리모형을 통한 기초연구가 부족한 상황이다. 본 연구에서는 강변저류지의 홍수저감효과를 분석하기 위하여 부정류 수리실험을 수행하였다. 강변저류지 설계시 고려인자인 설치위치, 유입부 마루높이 및 강변저류지 면적 등을 수리실험에서 다양한 조건으로 반영하여 수리실험을 수행하였다. 강변저류지의 홍수저감효과는 설치위치가 가까운 경우 가장 효과가 클 것으로 판단되며, 월류부 마루높이는 최대한 낮게 설치하는 것이 홍수저감에 효과적인 것으로 나타났다. 강변저류지 면적이 커질수록 홍수저감효과 또한 증가하지만, 기대할 수 있는 최대저감효과는 한계값에 수렴할 것으로 판단된다. 본 연구를 통하여 관측되고 분석된 결과는 강변저류지 설계시 유용하게 활용될 수 있을 것으로 판단된다. Detention basin is highly effective hydraulic structure which is available for flood mitigation and ecological characteristics. However, analysis of flood mitigation by detention basin is performed with numerical approaches only, there is not enough data obtained by experimental observation. In this study, physical experiment were performed under unsteady flow condition to analyze flood mitigation with detention basin. Various design factors such as location, later weir height and extent of detention basin were considered in this experimental observations. As the distance from detention base to target location become closer and later weir height become higher, we can expect more effective flood mitigation. As the area of detention basin area become lager, we also expect more higher flood mitigation effects. But, the flood mitigation effects from detention basin would converged to critical value. The obtained data will be useful for following studies about detention basin.

자동차부품 적용 저온분사 코팅기술

김형준,Kim, Hyung-Jun 대한용접접합학회 2006 대한용접·접합학회지 Vol.24 No.1

팬터그래프-전차선로 접촉부 영상처리 기술 개발

김형준,박영,조용현,조철진,김인철,Kim, Hyung-Jun,Park, Young,Cho, Yong-Hyeon,Cho, Chul-Jin,Kim, In-Chol 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.12

The measurement of dynamic stagger in electric railways is one of the key test parameters to increase speed and maintain safety in electric railways. This paper is introduces a non-contact optical-based measuring instrument of a catenary system in electric railways. The instrument is implemented by utilizing a CCD (Charge Coupled Device) camera installed on the roof of a vehicle for vision acquisition and image processing techniques including the Canny edge detector and the Hough transform to detect contact wires and calculate dynamic stagger. To check the validity of our approach for the intended application, we measured stagger of a overhead wire of a Korea Tilting Train (TTX). The non-contact optical-based measurement system proposed in this paper performs real-time stagger measurement of an activated high-voltage contact wire. By results of this paper, the instrument should be applied to assess performance and reliability of newly developed electric railway vehicles.