• 한국멀티미디어학회논문지
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• 제8권11호
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• pp.1472-1482
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• 2005

TOE (TCP/IP Offload Engine)는 부하가 많은 대규모 네트워크 서버에서 TCP/IP 프로토콜 처리의 부담을 줄이기 위해 고안된 하드웨어 장치이다. 본 논문에서는 TOE (TCP Offload Engine)를 사용하는 대규모 멀티미디어 서버를 위한 소켓 인터페이스 계층의 설계 및 구현에 대해 다룬다. 제안된 소켓 인터페이스 계층은 리눅스 운영체제 상에서 커널 모듈로 설계, 구현되었으며, BSD소켓 계층과 INET소켓 계층 사이에 존재하면서 응용 프로그램의 소켓 관련 요청을 TOE나 기존 INET소켓 계층으로 전달하는 역할을 한다. 본 논문에서 제안한 소켓 인터페이스는 소켓을 통해 TOE를 사용하는 응용 프로그램에 대해서 모든 표준 소켓 입출력 API와 파일 입출력 관련 API를 그대로 제공하고, 기존 응용 프로그램들에 대해서도 수정 없이 TOE의 기능을 그대로 사용할 수 있는 바이너리 수준의 호환성을 제공하며, 한 시스템에서 TOE와 이더넷 NIC을 동시에 사용할 수 있게 된다.

• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.69-75
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• 2010

새로운 휴대 이동 방송 방식인 고품질 지상파 DMB(Advanced T-DMB)시스템은 계층변조 방식을 이용하여 기존 T-DMB와 역호환성을 유지하면서 동일한 주파수 대역폭에서 전송률을 최대 2배로 높이기 위해 개발되었다. 이러한 고품질 지상파 DMB 시스템은 T-DMB의 DQPSK 변조신호에 새로운 변조가 적용된 BPSK 또는 QPSK 신호를 향상 계층으로 중첩하여 전송함으로써 기존 T-DMB의 고품질화를 실현한다. AT-DMB의 향상계층에 새로 추가되는 신호는 T-DMB와 역호환성 유지 및 방송권역 축소를 최소화하기 위해 크기가 충분히 작아야하는데, 추가되는 크기가 작은 신호는 전송채널에 존재하는 페이딩에 의해 쉽게 왜곡될 수 있다. 따라서 본 논문에서는 새로 추가되는 신호에는 오류정정 성능이 우수한 이중이진터보 (turbo) 부호를 적용하여 채널왜곡을 보상하고, 컴퓨터 시뮬레이션을 통해 이의 적용가능성을 분석하였다.

• Journal of Positioning, Navigation, and Timing
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• 제13권1호
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• pp.1-13
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• 2024

In this paper, we investigate the signal design of six (USA, EU, Russia, China, Japan, and India) countries for Global Navigation Satellite Systems (GNSS). Recently, a navigation satellite system that is capable of high-precision and reliable Positioning, Navigation, Timing (PNT) services has been developed. Prior to system design, a survey of the signal design for other GNSS systems should precede to ensure compatibility and interoperability with other GNSS. The signal design includes carrier frequency, Pseudorandom Noise (PRN) code, modulation, navigation service, etc. Specifically, GNSS is allocated L1, L2, and L5 bands, with recent additions of the L6 and S bands. GNSS uses PRN code (such as Gold, Weil, etc) to distinguish satellites that transmit signals simultaneously on the same frequency band. For modulation, both Binary Phase Shift Keying (BPSK) and Binary Offset Carrier (BOC) have been widely used to avoid collision in the frequency spectrum, and alternating BOCs are adopted to distinguish pilot and data components. Through the survey of other GNSS' signal designs, we provide insights for guiding the design of new satellite navigation systems.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2006년도 춘계학술발표대회
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• pp.1195-1198
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• 2006

기존의 컴퓨터 시스템에서는 인터넷의 대표적인 통신 프로토콜인 TCP/IP 가 호스트 CPU 에서 처리되는데, 이는 호스트 CPU 에 많은 부하(load)를 발생시켜 전체 시스템의 성능을 저하시키는 문제를 야기한다. 최근 이러한 문제점을 해결하는 방안으로서 네트워크 어댑터에서 TCP/IP 를 처리하는 TOE(TCP/IP Offload Engine)에 대한 연구가 활발히 진행되고 있다. 이러한 TOE 가 성공적으로 컴퓨터 시스템에 적용되는 위해서는 이를 지원하는 운영체제용 커널 모듈의 개발이 필요하며, 커널 모듈은 기존의 TCP/IP 를 위한 소켓 인터페이스를 바이너리 수준에서 호환성을 제공해야 한다. 따라서, 본 논문에서는 Linux 시스템에서 소켓 인터페이스에 대한 바이너리 수준의 호환성을 제공하는 TOE 용 커널 모듈을 제안하고 개발하였다. 또한, 실험의 통하여 TOE 커널 모듈이 CPU 에 부하를 거의 발생시키지 않음을 확인하였다.

• ETRI Journal
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• 제42권3호
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• pp.446-458
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• 2020

In this study, an efficient scheme for hiding data directly in partially encrypted versions of high efficiency video coding (HEVC) videos is proposed. The content owner uses stream cipher to selectively encrypt some HEVC-CABAC bin strings in a format-compliant manner. Then, the data hider embeds the secret message into the encrypted HEVC videos using the specific coefficient modification technique. Consequently, it can be used in third-party computing environments (more generally, cloud computing). For security and privacy purposes, service providers cannot access the visual content of the host video. As the coefficient is only slightly modified, the quality of the decrypted video is satisfactory. The encrypted and marked bitstreams meet the requirements of format compatibility, and have the same bit rate. At the receiving end, data extraction can be performed in the encrypted domain or decrypted domain that can be adapted to different application scenarios. Several standard video sequences with different resolutions and contents have been used for experimental evaluation.

• 전자공학회논문지S
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• 제35S권1호
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• pp.105-113
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• 1998

A new image processor is implemented for high-speed digital copiers and facsimiles. The imgage processor performs CCD and CIS interface, pre-processing, enlargement andreduction of gray level image, and various halftoning algorithms. Implemented halftoning algorithms are simple thresholding, fuzzy based mixed mode thresholding, dithering, and edge enhanced error diffusion. The result of binarization is transferred to a printer with serial or paralel output ports. Line by line pipelined data prodessing architecture is employed with time sharing access of the external memory. In receiving mode, it converts the resolution of received binary image for compatibility with conventional facsimile. In copy mode, a line of A3 paper with 400 dpi is processed with in 2.5 ms. The prototype of image processor was implemented usig Laser Programmable Gate Array (LPGA) with 0.8.mu.m technology.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.236-239
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• 1998

The in situ composites based on poly(ethylene 2,6-naphthalate) and thermotropic liquid crystalline polymer (LCP) have been an area of increasing interest and study, since LCP exhibits high chemical stabilities and excellent thermo mechanical properties such as high strength and modulus. In a binary, however, poor compatibility and interfacial adhesions between two phases frequently results in deteriorated mechanical properties. (omitted)

• 대한수학회지
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• 제47권5호
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• pp.1017-1029
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• 2010

In this paper we obtain a very general theorem of $\rho$-compatibility for three multivalued mappings, one of them from the class $\mathfrak{B}$. More exactly, we show that given a G-convex space Y, two topological spaces X and Z, a (binary) relation $\rho$ on $2^Z$ and three mappings P : X $\multimap$ Z, Q : Y $\multimap$ Z and $T\;{\in}\;\mathfrak{B}$(Y,X) satisfying a set of conditions we can find ($\widetilde{x},\;\widetilde{y}$) ${\in}$ $X\;{\times}\;Y$ such that $\widetilde{x}\;{\in}\;T(\widetilde{y})$ and $P(\widetilde{x}){\rho}\;Q(\widetilde{y})$. Two particular cases of this general result will be then used to establish existence theorems for the solutions of some general equilibrium problems.

• 전자공학회논문지A
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• 제32A권7호
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• pp.115-122
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• 1995

This paper presents the simulation environment that verifies whether a new microprocessor described with HDL is compatible with MS-DOS. The phrase 'compatible with MS-DOS' means that the microprocessor can execute MS-DOS without any modification of MS-DOS's binary code. The proposed verification environment consists of HDL simulator and user interface module. And the communications between them are performed by using sockets which UNIXprovide. The HDL simulator is equipped with several functions, which use PLI to emulate ROM-BIOS facilities. The ROM-BIOS emulation routine is described by using these functions. User interface module utilizes S/MOTIF and participates in emulating PC monitor and keyboard. The verification environment is tested by executing the MS-DOS commands (DIR, FORMAT, DATE, TIME etc.) with the HDL model of microprocessor, and the display of user interface module verifies that the environment works correctly. In this paper, the method of constructing the verification environment is presented, and the simulation results are summarized.

• Advances in concrete construction
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• 제6권2호
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• pp.123-143
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• 2018

Self compacting concrete (SCC) has good flowability, passability and segregation resistance because of voluminous cementitious material & high coarse aggregate to fine aggregate ratio, and high free water availability. But these factors make it highly susceptible to shrinkage. Fibers are known to reduce shrinkage in concrete mixes. Until now for conserving cement, only pozzolanic materials are admixed in concrete to yield a SCC. Hence, this study compares the use of wollastonite micro fiber (WMF), a cheap pozzolanic easily processed raw mineral fiber, and flyash in yielding economical SCC for rigid pavement. Microsilica was used as a complimentary material with both admixtures. Since WMF has large surface area ($827m^2/kg$), is acicular in nature; therefore its use in yielding SCC was dubious. Binary and ternary mixes were constituted for WMF and flyash, respectively. Paste mixes were tested for compatibility with superplasticizer and trials were performed on a normal concrete mix of flexural strength 4.5 MPa to yield SCC. Flexural strength test and restrained shrinkage test were performed on those mixes, which qualified self compacting criteria. Results revealed that WMF admixed pastes have high water demand, and comparable setting times to flyash mixes. Workability tests showed that 20% WMF with microsilica (5-7.5%) is efficient enough in achieving SCC and higher flexural strength than normal concrete at 90 days. Also, stress rate due to shrinkage was lesser and time duration for final strain was higher in WMF admixed SCC which encourages its use in yielding a SCC than pozzolanic materials.