• Proceedings of the IEEK Conference
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
• /
• pp.2236-2239
• /
• 2003

본 논문에서는 G.729A 와 SMV 음성 부호화기를 위한 새로운 파라미터 직접 변환 방식의 상호 부호화 알고리즘을 제안한다. 상호 부호화를 위하여 부가적인 복호화, 부호화 과정을 거쳐야하는 기존의 tandem 방식과 달리 제안된 파라미터 직접 변환 방식에서는 양 음성부호화기에서 공통적으로 사용하는 파라미터들이 직접 변환된다. SMV에서 G.729A로의 상호 부호화에서는 LSP 변환, 피치 지연 변환, 낮은 전송률에서의 상호 부호화 둥의 알고리즘을 제안하고, G.729A에서 SMV로의 상호 부호화에서는 LSP 변환, 피치 지연 변환, 전송률 결정 등의 알고리즘을 제안한다. 제안된 알고리즘을 다양한 방법으로 평가해본 결과 기존의 tandem 방식과 비교하여 계산량과 지연 시간을 줄이면서도 동등한 음질 또는 향상된 음질을 구현함을 확인할 수 있었다.

• Journal of Korean Society for Geospatial Information Science
• /
• 제13권2호
• /
• pp.39-43
• /
• 2005

In this study, we analyzed the accuracy of the conversion from DLT parameters to physical camera parameters and optimized the use of DLT model for non-metric cameras in photogrammetric tasks. Using the simulated data, we computed two sets of physical camera parameters from DLT parameters and Bundle adjustment for various cases. Comparing two results based on the RMSE values of check points, we optimized the arrangement of GCPs for DLT.

• Journal of KIISE:Software and Applications
• /
• 제41권7호
• /
• pp.501-517
• /
• 2014

Binary translation is a restructuring process in order to execute a program targeting a specific device on the other devices. In binary translation, it is very important to generate the translation rules between two devices. There are two methods for generating the translation rules, direct and indirect mapping. The direct mapping is the method for performance, while the indirect mapping is the method for retargetability. This paper suggests a binary translation method based on the direct mapping for the embedded systems. Because, however, the retargetability is also important requirement, we suggest the direct mapping based binary translation with considering the retargetability. In addition, we implement an automatic generation tool for translation rules to prove our concept. Through this method, we can generate the translation rules with considering the performance as well as the retargetability. Furthermore, we can reduce costs for the binary translation.

• Proceedings of the IEEK Conference
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
• /
• pp.222-225
• /
• 2003

본 논문에서는 six port 를 사용한 실시간 디지털 직접 변환 수신기를 소개하고 실제 six port 구조를 이용해 구현된 직접 변환 수신기의 성능을 분석한다. 제안한 알고리즘은 송신단과 수신단의 위상 오류를 보정하고 랜덤한 채널 잡음 환경에서도 성능의 저하가 크지 않다. 다음으로는 위상 오류 추정 방법을 사용하여 수신기에서의 성능 향상을 컴퓨터 시뮬레이션을 통해서 살펴보았다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• 제14권5호
• /
• pp.1071-1077
• /
• 2010

The six-port phase correlator using lumped elements was designed and fabricated in this paper, also the receiving performance of L-band direct conversion receiver using lumped six-port phase correlator element was analyzed. The proposed L-band lumped six-port phase correlator element was composed of a resistive power divider and the twist-wire coaxial cables. The proposed lumped six-port structure provides the small-sized configuration and wide-band characteristics. The performance of the L-band lumped direct conversion receiver structure was measured under the conditions of 1.69 GHz frequency for LO-CW signal and RF-QPSK signal, which are input signals for the lumped six-port phase correlator element. The direct conversion receiving structure using the proposed lumped six-port phase correlator element can recovered the good digital I/Q signal.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• 제40권6호
• /
• pp.71-83
• /
• 2003

In this paper, a novel transcoding algorithm for the G.729A and the Selectable Mode Vocoder(SMV) vocoders via direct parameter transformation is proposed. In contrast to the conventional tandem transcoding algorithm, the proposed algorithm converts the parameters of one coder to the other without going through the decoding and encoding processes. In transcoder from SMV to G.729A, LSP conversion algorithm, pitch delay conversion algorithm and transcoding algorithm in lower rate are proposed, and in transcoder from G.729A to SMV, LSP conversion algorithm, pitch delay conversion algorithm and rate selection algorithm are proposed. Evaluation results show that while exhibiting better computational and delay characteristics, the proposed algorithm produces equivalent or Improved speech quality to that produced by the tandem transcoding algorithm.

• The Bulletin of The Korean Astronomical Society
• /
• 제37권2호
• /
• pp.197.1-197.1
• /
• 2012

위성에서의 전력시스템은 임무를 수행하기 위하여 위성 본체와 탑재체에서 필요로 하는 전력을 생성, 저장, 조절 및 분배하는 역할을 수행한다. 특히, 태양전력 변환장치는 태양전지판에서 생성된 전력을 배터리와 연결된 일차 전력으로의 변환 및 배터리의 충전 제어를 담당한다. 태양전력 변환장치의 동작은 배터리의 특성과 자체 전력 변환 용량에 따라 직접에너지 전달 모드, 최대전력추적 모드, 테이프 모드, 정전압 모드 및 세류 충전 모드로 구분될 수 있다. 본 논문에서는 리튬 이온 배터리를 사용하는 위성에서 직접에너지전달 모드, 최대전력추적 모드 및 정전압 모드를 가지는 태양전력 변환장치에 대한 설계를 기술한다. 설계된 내용을 기반으로 제작된 태양전력변환장치에 대한 궤도상에서의 실제 동작 특성을 분석하여 설계를 검증한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• 제5권2호
• /
• pp.47-55
• /
• 1987

In this paper, the direct linear transformation is described in which a inner and exterior orientation parameters are treated as unknown for non-iterative direct space resection, and the computer program was developed to obtain object space coordinates. Image coordinates measurements are conducted with analogue stereo-plotter and digitizer. To prove the appropriateness of the two image coordinate measurement devices and the DLT method, the standard errors of object space coordinates are compared with semi-analytical method.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• 제40권6호
• /
• pp.61-70
• /
• 2003

In this paper, a transcoding algorithm for the Selectable Mode Vocoder (SMV) and the G.723.1 speech coder via direct parameter transformation is proposed. In contrast to the conventional tandem transcoding algorithm, the proposed algorithm converts the parameters of one coder to the other without going through the decoding and encoding process. The proposed algorithm is composed of four parts: the parameter decoding, line spectral pair (LSP) conversion, pitch period conversion, excitation conversion and rate selection. The evaluation results show that the proposed algorithm achieves equivalent speech quality to that of tandem transcoding with reduced computational complexity and delay.

• Proceedings of the IEEK Conference
• /
• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
• /
• pp.361-364
• /
• 2000

One of the problems using DCR(Direct Conversion Receiver) are DC offset, poor channel selectivity. APDP(Anti Parallel Diode Pair) can be good candidate for DCR frequency mixer due to its inherent End harmonic suppression. APDP shows good IP2 and DC suppression. This paper describe single APDP LO power characteristics, IP2, and receiver structure utilizing APDP frequency mixer