• 한국전자파학회논문지
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• 제15권11호
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• pp.1034-1042
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• 2004

본 논문에서는 64-QAM 디지털 무선중계 장치에 적용할 목적으로 주파수 선택적 페이딩 책 중의 하나인 아날로그 기울기 등화기의 이론적 모델, 구현 및 성능을 제시하였다. 또한 주파수 선택적 페이딩에 대해 기저대역 의 채널 모델링을 통해 I 및 Q 채 널의 상호간섭을 분석 하였고, 이 를 근거로 IF 대역에서 아날로그 기울기 등화기 구현을 위한 방법을 유도하였다. 페이딩을 받은 채널에 대해 기울기 등화기의 적용 유무에 따라 시간 및 주파수 영역에서 각각 신호의 영향을 살펴보았다. 그리고 무선중계 장치의 성능을 나타내는 시그너쳐(signature)를 통해 비트 오율 $10^{-3}$ 기준으로 신호 대역폭의 가장자리에서 약 6.2 dB 개선됨을 보였다.

• 한국군사과학기술학회지
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• 제25권3호
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• pp.251-258
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• 2022

Infrared stealth technology used in aircraft is applied to reduce the infrared signal by controlling surface temperature and emissivity using internal heat sink, low emissivity material or metamaterial. However, there is one part of the aircraft where the use of this technology is limited, and that is the radome. Especially, radome should have transmittance for the specific radio frequency, therefore, common stealth technology such as emissivity control surfaces cannot be applied to radome surface. In this study, we developed metal nano-coating for infrared stealth which is applicable to radome surface. We designed slot-type pattern for frequency selective transmission in X-band, and also controlled thickness of metal nano-coating for long wavelength infrared emissivity control. As a result, our infrared stealth surface for radome has 93.2 % transmittance in X-band and various infrared emissivities from 0.17 to 0.57 according to nano-coatings thickness. Also, we analyzed infrared signature of radome through numerical simulation, and finally reduced contrast radiant intensity by 97.57 % compared to polyurethane surface.

• 한국전자파학회논문지
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• 제12권5호
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• pp.777-786
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• 2001

본 논문에서는 64-QAM 디지털 무선 전송장치에 적용할 목적으로 주파수 선택적 페이딩 대책 중의 하나인 디지털 기울기 등화기의 원리, 채널 모델링 및 디지털 구현방법을 분석하였다. 또한 복소 13-탭 시간영역의 적응 등화기 칩과 연동시의 성능분석을 수치계산으로 수행하였으며, 장치의 signature 특성을 통과대역 가장자리에서 약 4.5 dB 개선시킬 수 있음을 보였다. 그리고 디지털 기울기 등화기의 모델링에 대한 한계, 동작 자파수, 제어계수, 신호의 constellation, 장치의 성능에 대한 다양한 결과도 검토하였다. 끝으로 61 MHz 클럭까지 동작시험을 검증한 디지털 기울기 등화기의 칩에 대한 기능을 소개한다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2007년도 동계학술대회
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• pp.154-157
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• 2007

It has been widely believed that one can obtain $\iota$-Hierarchical Identity Based Encryption (HIBE) scheme secure against chosen ciphetext attacks from ($\iota$+1)-HIBE scheme secure against chosen plaintext attacks. In this paper, however, we show that when applying two concrete HIBE schemes that Boneh et al. [1, 2] proposed, chosen ciphertext secure $\iota$-HIBE schemes are directly derived from chosen plaintext secure $\iota$-HIBE schemes. Our constructions are based on a one-time signature-based transformation that Canetti et at.[3] proposed. The security of our schemes is proved in the selective-ID suity model without using random oracles.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.428-434
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• 2004

Coarse clumping of solid materials within diseased biological cells can have a marked influence on the light scattering pattern. Perturbations in refractive index lead to distinct varia­tions in the cytometric signature, especially apparent over wide scattering angles. The large dynamic range of scattering intensities restricts collection of data to narrow angular intervals be­lieved to have the highest potential for medical diagnosis. We propose the use of an interfer­ence filter to reduce the dynamic range. Selective attenuation of scattering intensity levels is expected to allow simultaneous data collection over a wide angular interval. The calculated angu­lar transmittance of a commercial shortwave-pass filter of cut-off wavelength 580 nm indicates significant attenuation of scattering peaks below ${\~}\;10^{circ}$, and reasonable peak equalization at higher angles. For the three-dimensional calculation of laser light scattered by cells we use a spectral method code that models cells as spatially varying dielectrics, stationary in time. How­ever, we perform preliminary experimental testing with the interference filter on polystyrene microspheres instead of biological cells. A microfluidic toolkit is used for the manipulation of the microspheres. The paper intends to illustrate the principle of a light scattering detection system incorporating an interference filter for selective attenuation of scattering peaks.

• 한국정보통신학회논문지
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• 제19권4호
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• pp.800-806
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• 2015

WAVE(Wireless Access in Vehicular Environments) 시스템은 차량이 고속 이동 환경에서 차량 간 또는 차량과 인프라 간 패킷을 주고받을 수 있는 무선 통신 기술이다. 본 연구에서는 차량이 WAVE 시스템에서 통신 할 때 상대방의 인증서가 폐기 되었는지 확인하기 위한 CRL(Certificate Revocation List) 다운로드 프로토콜을 설계하고 구현하였다. WAVE 시스템은 UDP 상에서 동작하도록 하였으며, 보안기능을 지원하기 위해 ECDSA(Elliptic Curve Digital Signature Algorithm)를 사용하여 상호 인증을 하고 ECIES(Elliptic Curve Integrated Encryption Scheme)를 사용하여 기밀성을 보장한다. 또한 CRL 데이터에 MAC(Message Authentication Code)을 추가하여 데이터의 무결성을 보장하고, 선택적 재전송 방식(Selective Repeat Automatic Repeat Request)을 이용하여 데이터의 에러 및 흐름 제어를 수행한다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권4호
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• pp.539-546
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• 2020

Objective: The Jeju native pig (JNP) found on the Jeju Island of Korea is a unique black pig known for high-quality meat. To investigate the genetic uniqueness of JNP, we analyzed the selection signature of the JNP in comparison to commercial pigs such as Berkshire and Yorkshire pigs. Methods: We surveyed the genetic diversity to identify the genetic stability of the JNP, using the linkage disequilibrium method. A selective sweep of the JNP was performed to identify the selection signatures. To do so, the population differentiation measure, Weir-Cockerham's F_st was utilized. This statistic directly measures the population differentiation at the variant level. Additionally, we investigated the gene ontologies (GOs) and genetic features. Results: Compared to the Berkshire and Yorkshire pigs, the JNP had lower genetic diversity in terms of linkage disequilibrium decays. We summarized the selection signatures of the JNP as GO. In the JNP and Berkshire pigs, the most enriched GO terms were epithelium development and neuron-related. Considering the JNP and Yorkshire pigs, cellular response to oxygen-containing compound and generation of neurons were the most enriched GO. Conclusion: The selection signatures of the JNP were identified through the population differentiation statistic. The genes with possible selection signatures are expected to play a role in JNP's unique pork quality.

• Applied Science and Convergence Technology
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• 제24권3호
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• pp.53-59
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• 2015

The field-effect transistors (FETs) with a graphene-based p-n junction channel were fabricated using the patterned self-assembled monolayers (SAMs). The self-assembled 3-aminopropyltriethoxysilane (APTES) monolayer deposited on $SiO_2$/Si substrate was patterned by hydrogen plasma using selective coating poly-methylmethacrylate (PMMA) as mask. The APTES-SAMS on the $SiO_2$ surface were patterned using selective coating of PMMA. The APTES-SAMs of the region uncovered with PMMA was removed by hydrogen plasma. The graphene synthesized by thermal chemical vapor deposition was transferred onto the patterned APTES-SAM/$SiO_2$ substrate. Both p-type and n-type graphene on the patterned SAM/$SiO_2$ substrate were fabricated. The graphene-based p-n junction was studied using Raman spectroscopy and X-ray photoelectron spectroscopy. To implement low voltage operation device, via ionic liquid ($BmimPF_6$) gate dielectric material, graphene-based p-n junction field effect transistors was fabricated, showing two significant separated Dirac points as a signature for formation of a p-n junction in the graphene channel.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.212-212
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• 2022

Soluble starch synthase (SS) IV-2 is one of the starch synthase gene family members and responsible for starch chain elongation interacting with other rice eating and cooking quality controlling genes (e.g., AGPlar and PUL). SSIV-2 is mainly expressed in leaves, especially at grain-filling stage and its alleles can significantly affect rice quality. Here, we investigated the genetic diversity and population structure analyses of SSIV-2 gene by using 374 rice accessions. This rice set was grouped into 320 cultivated bred (subsequently classified into temperate japonica, indica, tropical japonica, aus, aromatic and admixture) and 54 wild rice. Haplotyping of cultivated rice accessions provided a total of 7 haplotypes, and only three haplotypes are functional indicating four substituted SNPs in two exons of chromosome 5: T/A and G/T in exon 4, and C/G and G/A in exon 13. Including the wild, a highest diverse group (0.0041), nucleotide diversity analysis showed temperate japonica (0.0001) had a lowest diversity value indicating the origin information of this gene evolution. Higher and positive Tajima5s D value of indica (1.9755) indicate a selective signature under balancing selection while temperate japonica (-0.9018) was in lowest Tajima's D value due to a recent selective sweep by positive selection. We found the most diverse genetic components of the wild in PCA but shared in some portion with other cultivated groups. Fixation index (F_ST-values) and phylogenetic analysis indicate a closer relationship of the wild with indica (F_ST=0.256) than to its association to both of temperate japonica (F_ST=0.589). Structure analysis shows a clear separation of cultivated subpopulations at every K value, but genetic components were admixed within the wild illustrating the same genetic background with japonica and indica in some proportion.

• ETRI Journal
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• 제33권4호
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• pp.600-610
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• 2011

This paper presents a novel approach to face detection by localizing faces as the goal-specific saliencies in a scene, using the framework of selective visual attention of a human with a particular goal in mind. The proposed approach aims at achieving human-like robustness as well as efficiency in face detection under large scene variations. The key is to establish how the specific knowledge relevant to the goal interacts with the bottom-up process of external visual stimuli for saliency detection. We propose a direct incorporation of the goal-related knowledge into the specification and/or modification of the internal process of a general bottom-up saliency detection framework. More specifically, prior knowledge of the human face, such as its size, skin color, and shape, is directly set to the window size and color signature for computing the center of difference, as well as to modify the importance weight, as a means of transforming into a goal-specific saliency detection. The experimental evaluation shows that the proposed method reaches a detection rate of 93.4% with a false positive rate of 7.1%, indicating the robustness against a wide variation of scale and rotation.