• 지구물리와물리탐사
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• 제7권3호
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• pp.191-196
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• 2004

탄성파 역산에는 고전적인 Gauss-Newton 방법이 주로 사용된다. 이 방법은 Jacobian을 직접 계산하여 거대한 크기의 Hessian 행렬을 만드는 것을 필요로 한다. Hessian 행렬의 구성은 몇 가지의 요소들에 의해 결정되는데, 음원과 수진기의 위치, 영상화 구역(image zone), 음원 파형의 형태 등 다양한 형태의 모델링에 영향을 미치는 요소에 따라서 다른 모습으로 나타난다. 이 논문에서는 Gauss-Newton 방법에 나타나는 거대한 Hessian 행렬을 조절함으로써 Marmousi 탄성파 모델 자료를 역산하고자 한다. 또한 근사 Hessian행렬의 대안으로 두 가지의 유사 Hessian행렬들을 제시하고자 한다. 하나는 유한 폭을 갖는 Hessian행렬이고 다른 하나는 자동안정함수(automatic gain function, AGC)를 이용한 Hessian 행렬이다. 작은 크기의 모델에 대한 수치결과로부터 몇 가지의 사실을 알 수 있다. 하나는 유한 폭을 갖는 Hessian 행렬을 이용하여 얻어진 한번 근사된 속도모델은 원래의 Hessian 행렬을 이용하여 얻은 결과와 매우 유사하다는 것이고, 둘째로 자동안정함수를 이용한 근사 Hessian 행렬의 안정성이 많이 개선된다는 것이다.

• 동의신경정신과학회지
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• 제11권2호
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• pp.53-62
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• 2000

Background : The aim of this study was to evaluate the effect of Punsimgieumgamibang on insomnia and anxiety. which is widely used in mental diseases. Method : We admitted Punsimgieumgamibang into rats which illumination of the sleeping periodhas been reversed, and measured its activity rate during the sleeping period. Also we studied the effect of Punsimgieumgamibang on anxiety using analyses of Punsimgieumgamibang on anxiety using analyses of behavior of rats submitted to the elevated plus-maze test.Result : 1) The sleeping ratio of the Pusimgieumgamibang group was higher than the control group on the whole, and the difference of the groups in the third time block was significant statistically. 2) We could not find any statistical information in all of the 4 anxiety related behavior of the elevated plus-maze experiment. and there was a tendency to a higher measurement in the Punsimgieumgamibang group animals in the total arms visitation in the elevated plus-maze, open arms visitation, and the amount of time of stay in arms. Conclusion : It is suggested that Pusimgieumgamibang has effects on insomnia.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.207.1-207.1
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• 2014

High-mobility and two dimensional conduction at the interface between two band insulators, LaAlO3 (LAO) and SrTiO3 (STO), have attracted considerable research interest for both applications and fundamental understanding. Several groups have reported the photoconductivity of LAO/STO, which give us lots of potential development of optoelectronic applications using the oxide interface. Recently, a giant photo response of Pd nano particles/LAO/STO is observed in UV illumination compared with LAO/STO sample. These phenomena have been suggested that the correlation between the interface and the surface states significantly affect local charge modification and resulting electrical transport. Water and gas adsorption/desorption can alter the band alignment and surface workfunction. Therefore, characterizing and manipulating the electric charges in these materials (electrons and ions) are crucial for investigating the physics of metal oxide. Proposed mechanism do not well explain the experimental data in various ambient and there has been no quantitative work to confirm these mechanism. Here, we have investigated UV photo response in various ambient by performing transport and Kelvin probe force microscopy measurements simultaneously. We found that Pd nano particles on LAO can form Schottky contact, it cause interface carrier density and characteristics of persistence photo conductance depending on gas environment. Our studies will help to improve our understanding on the intriguing physical properties providing an important role in many enhanced light sensing and gas sensing applications as a catalytic material in different kinds of metal oxide systems.

• KIEAE Journal
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• 제7권1호
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• pp.65-72
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• 2007

As ecological design elements, daylighting can be applied to provide adequate illumination on visual tasks to create an attractive visual environment and to save electrical energy. Daylighting control systems reject direct sunlight and penetrate it onto the ceiling or to deep into the room. This study aims to evaluate the luminance environment of sloped light guide with automated venetian blind systems according to sun angle changes. For evaluation, a mock-up model was used and the south facing side-window mounted between the clerestory window and the view window. To assess luminance performance, 3 view points of luminance were monitored. As results, the conventional and lightshelves show ideal luminance ratio between workplane and surroundings(3:1) and workplane and darkness area(2:1) due to total ratio of surroundings and darkness area has lower ratio than workplane. Compared to the lightshelves window, conventional window shows unrelieved effect in between the workplane and brightness area(1:5). It means that there has low deviation according to the required standards. Also, compared to the ratio between the brightness area and darkness area(2~6:1) conventional window with high deviation(10~20:1) provide discomfort glare due to the excessively strong contrast, while lightshelves window shows a required luminance ratio that provide a three-dimensional effect to occupants. Therefore, luminance distribution indicate that application of a lightshelves and blinds not only has a significantly positive effect but also offers higher luminance quality in a daylit room

• 한국산학기술학회논문지
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• 제13권1호
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• pp.329-332
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• 2012

LED는 저 전력, 긴 수명, 고 휘도, 빠른 응답, 친환경적인 특성의 여러 장점을 갖고 있기 때문에 청색과 녹색 LED는 교통신호, 옥외 디스플레이, 백색 LED는 LCD 후면광 등의 응용 제품에 사용되고 있다. 여기서 LED의 성능을 향상하기 위하여 출력전력과 소자의 신뢰성을 높이고, 동작전압을 낮추어야 LED 칩의 고효율화가 이루어져야 하는데, 이는 에피택셜층, 표면요철, 패턴이 있는 사파이어 기판, 칩 설계의 최적화, 특수 공정의 개선 등의 기술이 우수해야 한다. 본 연구에서는 측면 에칭 기술과 절연층 삽입기술을 이용하여 사파이어 에피 웨이퍼 위에 GaN-기반 백색 LED 칩을 제작하여 그 성능을 조사하였다. LED 칩의 성능을 개선하기 위한 최적화 설계와 CBL(current blocking layer) 삽입 기술의 개선된 공정을 통하여 LED 칩 성능의 향상을 확인할 수 있었으며, 출력 전력은 광 출력 7cd, 순방향 인가전압 3.2V의 값을 얻었다. 현재의 LCD 후면광원으로 사용되고 있는 LED 칩의 출력에 비하여 성능이 개선되었으며, 의료기기 및 LCD LED TV의 후면광원으로 사용할 수 있을 것으로 기대된다.

• 한국동물위생학회지
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• 제41권2호
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• pp.91-95
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• 2018

Polioencephalomalacia (PEM) is a neurologic disease of ruminants diagnosed by pathological approach. There is very little information available to understand bovine PEM in Korea. In this study, we investigated the diagnostic rate and pathological features of PEM in 334 necropsied cases of cattle submitted to the Animal and Plant Quarantine Agency in Korea from 2015~2017. PEM was diagnosed only in 13 (3.9%) Hanwoo, the Korean native cattle, and sporadically occurred in our country. The disease was the most diagnosed in fall season, and the age of the cows ranged from 1 month to 3 year. In all PEM cases, softening, and yellow discoloration of the gray matter in the cerebrum and fluorescence at the sites using ultraviolet illumination were grossly observed. Microscopically abundance of glial cells with vacuolar large cytoplasm and neuronal necrosis were commonly observed. This study suggests that future studies are necessary to identify the cause and pathogenesis for the control of PEM in our country.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.5904-5927
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• 2019

Many artificial intelligence (AI) techniques have been embedded into various engineering technologies to assist them in achieving different goals. The integration of modern technologies with energy consumption management system and occupant's comfort inside buildings results in the introduction of intelligent building concept. The major aim of this integration is to manage the energy consumption effectively and keeping the occupant satisfied with the internal environment of the building. The last few couple of years have seen many applications of AI techniques for optimizing the energy consumption with maximizing the user comfort in smart buildings but still there is much room for improvement in this area. In this paper, a hybrid of two AI algorithms called firefly algorithm (FA) and genetic algorithm (GA) has been used for user comfort maximization with minimum energy consumption inside smart building. A complete user friendly system with data from various sensors, user, processes, power control system and different actuators is developed in this work for reducing power consumption and increase the user comfort. The inputs of optimization algorithms are illumination, temperature and air quality sensors' data and the user set parameters whereas the outputs of the optimization algorithms are optimized parameters. These optimized parameters are the inputs of different fuzzy controllers which change the status of different actuators according to user satisfaction.

• 한국산업정보학회논문지
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• 제17권6호
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• pp.19-24
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• 2012

본 논문에서는 상업용 아임센서터치 전자칠판(Interactive Whiteboard System, IWB)을 소개한다. 이 시스템은 손가락이나 펜을 이용하여 접촉식 상호작용이 가능한 화이트보드 스크린을 통해 개인용 컴퓨터를 운용할 수 있도록 도와주는 인터페이스(Interface)이다. 제안된 인터페이스는 윈도우즈 운영체제와 상호작용하며, 온도와 조명의 변화에 적응적으로 동작한다. 제안된 시스템은 카메라에서 입력된 수광부(Optical Receptive Field)의 영상을 참조영상과 비교하여 차이를 계산하고, 그 차이를 이용하여 터치스크린의 좌표값을 계산한다. 계산된 좌표값을 기반으로 윈도우즈 마우스 이벤트를 생성하여 윈도우즈시스템으로 전달한다. 우리는 참조영상을 갱신하기 위해 두 개의 스레드(Thread)을 이용한 임계영역을 구현하고, 차이계산의 신뢰성을 위해 적응적 임계값을 이용한 참조영상의 갱신을 구현한다. 제안된 터치스크린 인터페이스를 장착한 전자칠판 시스템은 향후 국내외 시장의 성장률이 높아 전도유망한 상품이며, 시장성이 밝을 것으로 기대한다.

• 한국수소및신에너지학회논문집
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• 제11권1호
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• pp.29-41
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• 2000

Anaerobic fermentation using Clostridium butyricum NCIB 9576, and photo-fermentation using Rhodopseudomonas sphaeroides E15-1 were studied for the production of hydrogen from Makkoli, fruits (orange & apple, watermelon & melon) and Tofu wastewaters. From the Makkoli wastewater, which contained $0.94g/{\ell}$ sugars and $2.74g/{\ell}$ soluble starch, approximately $49mM\;H_2/{\ell}$ wastewater was produced during the initial 18h of the anaerobic fermentation with pH control between 6.5-7.0. Several organic acids such as butyric acid, acetic acid, propionic acid, lactic acid and ethanol were also produced. From Watemlelon and melon wastewater, which contained $43g/{\ell}$ sugars, generated about approximately $71mM\;H_2/{\ell}$ wastewater was produced during the initial 24 h of the anaerobic fermentation. Tofu wastewater, pH 6.5, containing $12.6g/{\ell}$ soluble starch and $0.74g/{\ell}$ sugars, generated about $30mM\;H_2/{\ell}$ wastewater, along with some organic acids, during the initial 24 h of anaerobic fermentation. Makkoli and Tofu wastewaters as substrates for the photo-fermentation by Rhodopseudomonas sphaeroides E15-1 produced approximately 37.9 and $22.2{\mu}M\;H_2/m{\ell}$ wastewaters, respectively for 9 days of incubation under the average of 9,000-10,000 lux illumination at the surface of reactor using tungsten halogen lamps. Orange and apple wastewater, which contained 93.4 g/l, produced approximately $13.1{\mu}M\;H_2/m{\ell}$ wastewater only for 2 days of photo-fermentation and the growth of Rhodopseudomonas sphaeroides E15-1 and hydrogen production were stopped.

• 한국광학회지
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• 제27권2호
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• pp.73-80
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• 2016

본 논문에서는 광생물 반응기의 조명 시스템에 적용할 수 있는 LED(Light-Emitting Diode)와 태양광 하이브리드 광원을 이용한 도광판의 설계 및 제작 결과에 대해 보고한다. LED용 도광판 패턴을 설계하고 기존에 보고된 태양광용 도광판에 함께 중첩하여 가공하였다. 하이브리드 도광판의 출력 PFD(Photon Flux Density)를 일정하게 유지시켜주기 위한 제어 시스템을 제작하였으며, 출력 PFD 목표값을 $70{\mu}E/(m^2{\cdot}s)$로 설정하였을 경우 오차범위 ${\pm}2%$ 이내에서 제어가 이루어짐을 확인하였다.