• 한국통신학회논문지
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• 제25권6B호
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• pp.1021-1027
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• 2000

In this paper, we propose two new detection-estimation based algorithms that effectively remove impulsive noises in severely corrupted color images. The existing methods for enhancing corrupted color images with impulsive noises commonly possess the inherent problems of excessive computing time and smoothing out edges. However, since our proposed algorithms classify corrupted pixels first in each channel or in each pixel and then perform marginal or vector median filtering only for them, are computationally efficient and preserve edges well. In addition, since there are no appropriate criteria to evaluate the performance of impulsive noise detectors for color images, the objective comparison of noise detectors is difficult. Thus, we introduce a new efficiency factor to compare the performance of noise detectors in digital color images. Simulation results show that the proposed algorithms perform better than the existing methods in terms of both objective and subjective evaluat ons.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2408-2410
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• 2003

본 논문에서는 여러 대의 모바일 로봇을 이용해 미지의 환경에 대한 맵핑을 보다 빠르고 효율적으로 행할 수 있는 방법을 제시한다. 각각의 모바일 로봇은 충돌 회피, 경로 설정 등의 기능 이외에 서버와의 통신 및 로봇간의 통신을 통해 맵핑에 관한 정보를 공유해 빠른 시간이내에 신뢰할만한 맵핑을 행할 수 있고 서버에서의 명령을 통해 부가적인 기능을 수행할 수 있다. 여러 대의 모바일 로봇을 이용한 맵핑에서 가장 중요한 것은 신뢰할만한 Navigation 이다. 이를 위해 엔코더와 ONS(Optical Navigation System)을 이용해 정확한 Localization을 행하였으며, 초음파 센서를 이용해 장애물의 위치 및 거리를 파악해 미지의 영역에 대한 맵핑을 수행하였다. 제안된 방법의 검증을 위해 시뮬레이션을 행하였다.

• Bulletin of the Korean Chemical Society
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• 제15권9호
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• pp.766-771
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• 1994

A number of molybdenum(VI), -(V), and -(IV) oxo complexes with S-methyl 3-(2-hydroxyphenyl)methylenedithiocarbazate and its derivatives as the ONS-donor metal-binding substrate are synthesized. The Mo(VI)-dioxo complexes are cis-dioxo Mo$O_2$L(D), where D is solvent molecules such as MeOH, DMF, Py(pyridine), DMSO, and ${\gamma}$-Pic(${\gamma}$-picoline). The Mo(V)-oxo complexes are of the type (PyH)[MoO(NCS$)_2$L] with an octahedral geometry. The Mo(IV)-oxo complexes, MoOL are derived from corresponding Mo(VI)-dioxo complexes by oxo abstraction with PP$h_3$. The complexes are characterized by IR, $^1$H-NMR, UV-Vis spectroscopy and cyclic voltammetry. On the basis of ligand displacement reaction, the qualitative order of D binding for Mo$O_2$L(D) complexes is also discussed.

• 한국광학회지
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• 제3권3호
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• pp.172-177
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• 1992

레이저 광선의 시준정도를 정확하게 측정하기 위하여 새로운 양방향 층밀리기 간섭계를 구성하였다. 한개의 쐐기판과 두개의 평면거울로 구성된 간섭계는 서로 반대방향으로 층밀리기된 두개의 간섭무늬 모양에 의햐여 시준정도를 나타낸다. 새로운 간섭계는 기존의 방법들에 비하여 분해능이 두 배로 향상되었으며 또한 간섭무늬 자체내에 시준된 경우를 나타내는 기준표시도 갖는다. 쐐기판의 $90^{\circ}$ 회전에 의한 간섭무늬 변화와 두 간섭무늬를 서로 중첩시켜 생긴 무아레 무늬 등에 의한 시준측정에 관하여 자세리 논하였으며 측정결과도 제시하였다.

• 정보보호학회논문지
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• 제24권4호
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• pp.635-643
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• 2014

인터넷을 통하여 제공되는 대부분의 웹 서비스들은 웹 브라우저를 통하여 사용자에게 제공된다. 웹 브라우저는 텍스트 형태의 웹 페이지를 서버로부터 수신하여 해석하고 사용자에게 보여준다. 웹 브라우저는 추가적으로 설치 할 수 있는 각종 기능들을 통하여 확장성을 제공한다. 하지만 추가로 설치 할 수 있는 기능들도 웹 페이지에 접근하여 내용을 위/변조 할 수 있다는 점에서 웹 브라우저를 통한 웹 서비스는 보안상 문제점을 내포할 수 있다. 웹 브라우저는 웹 페이지정보를 DOM구조의 형태로 메모리에 저장한다. 웹 페이지의 변조를 방지하기 위한 방법으로는 DOM구조의 특정 부분에 해쉬(hash)값을 적용하는 방법이 있다. 하지만 웹 페이지의 특성상 해쉬를 이용한 대응방안이 효과를 발휘할 수 없는 부분이 있다. 즉, 사용자가 직접 입력하는 부분은 정해진 입력 값이 아니기 때문에 미리 해쉬 값을 계산 해 놓을수도 없고 따라서 임의로 변조되는 것을 막을 수 없다. 본 논문에서는 웹페이지에 입력되는 사용자 입력 값의 위조나 변조를 방지 또는 탐지하는 방안을 제안한다. 제안 방법은 사용자가 키보드를 사용하여 입력하는 입력 값을 저장 해 놓았다가 웹 브라우저가 입력 값을 전송하는 순간 저장된 입력 값과 전송되는 값을 비교하여 변조 여부를 파악한다.

• E2M - 전기 전자와 첨단 소재
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• 제9권2호
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• pp.146-151
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• 1996

PZT powders were prepared by the molten salt synthesis method. The porous PZT ceramics were made from a mixture of PZT and polyvinylalcohol(PVA) by BURPS(Bumout Plastic Sphere) technique. The 3-3 type composites were fabricated by impregnating an sintered porous PZT ceramics with various polymer matrices. The relative permittivity of 3-3 type composite specimens was shown 860-1,100 smaller than that of solid PZT ceramics(2,100), and the dissipation factors of composite specimens were about 0.02 to 0.03. The piezoelectric coefficient d$_{33}$ of composite specimens(285-328*10$^{12}$ C/N) was comparable with that of single phase PZT specimens(364*10$^{-12}$ C/N). The thickness mode coupling factor k$_{t}$(O.5-0.6) of composite specimens was comparable with that of single phase PZT specimens(k$_{t}$-0.7), and the mechanical quality factor of composite specimens was smaller than 10, and thus these 3-3 type composite specimens would be believed as a good candidates for broad band transducer applications.ons.

• Management Science and Financial Engineering
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• 제3권2호
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• pp.1-27
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• 1997

Designing effective navigation aids for customer interfaces is critical for the success of cyber shopping malls. Navigation aids can be classified into either basic ones which are based on the structure of the malls or add-ons which are not. Add-on navigation aids provide various short-cuts to promote efficient traversal in the cyber shopping malls, but too many of them would increase the complexity of the customer interface. Metaphors have been used widely for the design of add-on navigation aids, but little research evaluates their impact on the processes and outcomes of customers behavior in cyber shopping malls. This paper presents an empirical study that investigates the navigation process of customers and the subjective evaluation of their shopping experience. This research implemented two versions of a test-bed cyber shopping mall according to different metaphors used; one based on a spatial metaphor, and the other based on a non spatial metaphor. The results of the experiment indicate that navigation aids based on the spatial metaphor were used more frequently, which resulted in better understanding about the entire structure of the cyber shopping malls, which in turn led to an increased ease of finding target items and also a more pleasant shopping experience. The benefits of navigation aids based on the spatial metaphor became more evident when customers were looking for ad-hoc category items rather than common items. This paper presents plausible explanations for the results and implications to the design of navigation aids for cyber shopping malls.

• 한국연초학회지
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• 제21권1호
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• pp.77-81
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• 1999

Tobacco plants(Nicotiana tabacum cv. NC82) transformed with TMV CP cDNA were self-fertilized until 8th generation (R$_{8}$), and the transgenic plants from 6th to 8th generation were analized for their resistance to tobacco mosaic virus(TMV) and stability of the gene expression. The 6th generation of the plants(R$_{6}$) showed high resistance(81-91 %) to TMV at eight weeks after artificial inoculation with the virus. The transgenic cell line 601 was the most prominant in the expression of resistance. 98 % of the plants showed no symptom without any agronomic phynotepe variation when they were inoculated with the virus in a experimental field. However, 2% of the plants were revealed as delay type of symptom with mild mosaic on a few leaves. The viral resistance in greenhouse tests of the 7th generation (R$_{7}$) was 54-64%, and the number of delay type plants were increased than that of 6th generation plants. In the 8th generation, 81 % of the plants was complete resistant to the virus. The TMV CP cDNA of the transgenic plants of each generation was also confirmed by genomic PCR, and there was no systemic viral multiplication in the resistant plants. It suggests that the viral resistance and gene expression of the transgenic plants might be stable through the generations.ons.s.

• 콘크리트학회지
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• 제7권4호
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• pp.129-136
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• 1995

이 연구는 쐐기쪼갬시험법에 의하여 강모래 콘크리트의 파괴에너지와 부순모래 콘크리트의 파괴에너지 측정을 통하여 콘크리트 강도와 파괴에너지 관계에 대하여 규명하였다. 그리고 부순모래 콘크리트의 파괴에너지와 강모래 콘크리트의 파괴에너지를 비교 검토하엿으며, 콘크리트의 특성길이도 구하였다. 이연구의 실험결과에 의하면 부순모래 콘크리트는 파괴특성 관점에서 강모래 콘크리트와 유사한 경향을 나타내고 있다. 그리고 압축강도가 20~60 MPa에서는 압축강도가 증가함에 따라 파괴에너지가 증가하였지만, 60 MPa이상의 범위에서는 압축강도가 증가하여도 파괴에너지는 증가하지 않았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.190-193
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• 2002

The processing technology of organic thin-film transistors (Ons) performances have improved fur the last decade. Gate insulator layer has generally used inorganic layer, such as silicon oxide which has properties of a low electrical conductivity and a high breakdown field. However, inorganic insulating layers, which are formed at high temperature, may affect other layers termed on a substrate through preceding processes. On the other hand, organic insulating layers, which are formed at low temperature, dose not affect pre-process. Known wet-processing methods for fabricating organic insulating layers include a spin coating, dipping and Langmuir-Blodgett film processes. In this paper, we propose the new dry-processing method of organic gate dielectric film in field-effect transistors. Vapor deposition polymerization (VDP) that is mainly used to the conducting polymers is introduced to form the gate dielectric. This method is appropriate to mass production in various end-user applications, for example, flat panel displays, because it has the advantages of shadow mask patterning and in-situ dry process with flexible low-cost large area displays. Also we fabricated four by four active pixels with all-organic thin-film transistors and phosphorescent organic light emitting devices.