• 한국ITS학회 논문지
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• 제10권5호
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• pp.87-92
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• 2011

본 논문에서는 800 ~ 900 MHz 주파수 대역에서 러시아 PNG 지역에 오쿠무라-하타 모델을 적용하여 경로 손실식을 구하였다. 기존의 경로 손실 모델을 이용하여 러시아 PNG 지역의 새로운 경로 손실 특성식을 구하기 위해서, 최소 자승 평균 기법을 적용하여 기존 모델에 대한 수정치를 구하였다. 자유 공간 및 하타 모델과 측정치의 수정치가 28, 13 dB 임을 알 수 있었으며, 이 값을 적용하여 러시아 PNG 지역에 맞는 새로운 경로손실 모델을 제시하였다.

• 한국인쇄학회지
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• 제20권1호
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• pp.146-158
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• 2002

JPEG is good for full color representation but is poor in quality of image because of the small size and the losing compression ways. GIF is a kind of format style made for image - transmission in Compuserve which is a method of PC communication in U. S. A and now is used in world wide web owing to the efficiency of file compression and transmission. But GIF only is used 256 colors, so the images in web has a poorer quality of colors effect to be compared with those of printed catalogues. Also there can be licence problems when the images is used for commercial uses because the possession is Compuserve. The PNG is a way that the total advantages of JPEG and GIF. PNG image file is a more skillful (bitmap display unit), shows a high quality image like TIFF image about, gives superior compression , a 10% to 30% represents full color, 256 color, gray like JPEG. GIF file which uses LZW compression file is a thing which pays licence, In other hands, PNG is free from licence and more skillful image processing method against image error, and it is possible to conserve the color information. Therefore, this treatise is about how various images which are utilized for commercial printings in web, can be made into PNG files about the compression file. And the representation of image by compared the G]U images with JPEG images as well as compression file and the representation of image the superiority of color representation. In addition, 1 check out how much ranges the PNG files are available for electronic publish printing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1622-1624
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• 1987

In general, pseudo noise generator(PNG) used for PLR System consists of linear feedback shift register. Based on a W.F. representation of shift registers, a method for analyzing operational characters & sequence of PNG are studied. PNG is characterized by the time-recursive equation & PNG sequence is analyzed by the output state variable equation. Methods studied in this paper are illustrated by appropriate example.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.578-583
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• 1992

In this paper, we show that various navigation constant values in PNG law can result in as optimal gains when we introduce proper time-varying weighting functions into the cost function of an optimal control problem. we then apply this idea to the guidance problem where we are required to achieve a given impact angle as well as the zero miss distance. As a result, we obtain a set of optimal guidance laws each of which could be related to a navigation constant in PNG. Some basic properties of these guidance laws are also presented.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.298-298
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• 2013

Finding renewable and clean energy resources is essential research to solve global warming and depletion of fossil fuels in modern society. Recently, complex harvesting of energy from multiple sources is available in our living environments using a single device has become highly desirable, representing a new trend in energy technologies. We report that when simultaneously driving the fusion and composite cells of two or more types, it is possible to make an affect the other cells to obtain a greater synergistic effect. To understand the coupling effect of photovoltaic and piezoelectric device, we fabricate the serially integrated hybrid cell (s-HC) based on organic solar cell (OSC) and piezoelectric nanogenerator (PNG). The size of increased voltage peaks when OSC and PNG are working on is larger than the case when only PNG is working. This voltage difference is the Voc change of OSC, not the voltage change of PNG and current density difference between these two cases is manifested more clearly. When the OSC and PNG are working in s-HC at the same time, piezoelectric potential (VPNG) is generated in ZnO and theoretical total voltage is sum of voltage of an OSC (VOSC) and VPNG. However, electrons from OSC are influenced by piezoelectric potential in ZnO and current loss of OSC in whole circuit decreases. As a result, VOSC increases temporarily. Current shows the similar behavior. PNG acts a resistance in the whole circuit and current loss occurs when the electrons from OSC pass through the PNG. But piezoelectric potential recover current loss and decrease the resistance of PNG. Our PNG can maintain piezoelectric potential when the strain is held owing to the LDH layer while general PNG cannot maintain piezoelectric potential. During the section that strain is held, voltage enhancement effect is maintained and same effect appeared even turn off the light. Actually at this time, electrons in ZnO nanosheets move to LDH and trapped by the positive charges in this layer. After this strain is held, piezoelectric potential of ZnO nanosheets is disappeared but potential difference which is developed by negative charge dominant LDH layer is remained. This potential acts similar role like piezoelectric potential in ZnO. Electrons from the OSC also are influenced by this potential and the more current flows.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.597-602
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• 1988

In this paper, we consider conventional and modified proportional navigation guidance(PNG) laws for a random maneuvering target. By means of Lyapunov function approach, we show that an ideal missile guided by the conventional PNG law can always intercept a random maneuvering target if some specified initial conditions are satisfied and the navigation constant is chosen sufficiently high. In addition, we propose a modified PNG law. At the final phase of pursuit, the proposed guidance law has a better acceleration profile than the conventional PNG law.

• 대한전기학회논문지
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• 제39권2호
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• pp.192-198
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• 1990

The performance of the proportional navigation guidance(PNG) law for a target with constant acceleration has been extensively studied in the prior literature. In this papaer, we consider the performance of the PNG law for a randomly maneuvering target. By means of Lyapunov method, we prove that an ideal missile guided by the conventional PNG law can always intercept a randomly maneuvering target if the initial missile heading error is small and the navigation constant is chosen sufficiently large. To the authors' best knowledge, this is the first analytic result on the performance of the PNG law for a target with time-varying acceleration.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2001년도 추계학술발표회 논문집
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• pp.305-313
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• 2001

• 농업과학연구
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• 제37권1호
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• pp.53-60
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• 2010

Two experiments were conducted to investigate the effect of probiotics on the malodor removal. In experiment 1, dietary effects (several malodorous gas concentration of excreta, dry matter metabolizability, and blood profiles) were determined using laying hens. A total of 30 Hy-line brown layers, 68-wk of age, were randomly allocated into 5 groups with 3 replicates of 2 birds each. The treatments were probiotics free, 0.2% and 0.4 % addition of mixed probiotics (Bacillus subtilis PNG-4 +Lactobacillus acidophilus LAS), and 0.2 and 0.4 % addition of single probiotics (Bacillus subtilis PNG-4). In experiment 2, the effects of mixing of probiotics into the excreta on the malodorous gas removal was investigated. There were three treatments (probiotics free, Bacillus subtilis PNG-4 +Lactobacillus acidophilus LAS, and Bacillus subtilis PNG-4) with three replicates. The malodorous gas concentrations were detected at 0, 3, 7 and 14 day of incubation. In experiment 1, ammonia concentration was significantly decreased by feeding mixed probiotics at 14th day of incubation. However, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan were not significantly affected by mixed probiotics. Dry matter metabolizability was significantly increased by feeding probiotics, but no significant differences between single and mixed probiotics. There was no significant differences in blood profiles. In experiment 2, mixing of probiotics into the excreta did not affect the concentration of ammonia, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan. Therefore, these experiments suggested that Bacillus subtilis PNG-4 + Lactobacillus acidophilus LAS supplementations could improve ammonia gas removal, and dry matter metabolizability in layers. Also, decrease of ammonia concentration was higher in mixed probiotics group compare to the single probiotics group. On the other hand, mixing of probiotics into the excreta appeared not to be a useful method.

• 한국항공우주학회지
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• 제37권10호
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• pp.998-1001
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• 2009

본 논문에서는 기존의 호밍유도법칙으로 널리 사용되는 상수 항법이득을 갖는 비례항법유도법칙이 속력 변화가 있는 경우에도 엄밀한 의미에서 최적해임을 보였다. 해석결과로부터 항법상수가 3인 경우 유도항력에 접근속력이 가중된 성능지수를 최소화하는 최적해임이 확인되었다. 비행체의 운동을 선형방정식으로 표현하고 속력변화를 고려하지 않은 기존 연구결과들과 달리 본 연구에서는 비선형 방정식을 기반으로 속력변화까지 고려하여 비례항법유도법칙의 최적성에 관한 보다 일반적인 해석 결과를 제시하였다.