• Journal of information and communication convergence engineering
• /
• 제10권3호
• /
• pp.242-247
• /
• 2012

In the determination of suitable frame sizes associated with dynamic framed slotted Aloha used in radio frequency identification tag identification processes, the widely imposed constraint $L=2^Q$ often yields inappropriate values deviating far from the optimal values, while a straightforward use of the estimated optimal frame sizes causes frequent restarts of read procedures, both resulting in long identification delays. Taking a trade-off, in this paper, we propose a new method for determining effective frame sizes where the effective frame size changes in a multiple of a predetermined step size, namely ${\Delta}$. Through computer simulations, we show that the proposed scheme works fairly well in terms of identification delay.

• Journal of the Optical Society of Korea
• /
• 제19권5호
• /
• pp.537-543
• /
• 2015

Liquid crystal displays (LCDs) have slow responses, so motion blurs are often perceived in fast moving scenes. To reduce this motion blur, we propose a novel method of robust motion compensated frame interpolation (MCFI) based on bidirectional motion estimation (BME) and weight-overlapped block motion compensation (WOBMC) with variable block sizes. In most MCFI methods, a static block size is used, so some block artefacts and motion blurs are observed. However, the proposed method adjusts motion block sizes and search ranges by comparing matching scores, so the precise motion vectors can be estimated in accordance with motions. In the MCFI, overlapping ranges for WOBMC are also determined by adjusted block sizes, so the accurate MCFI can be performed. In the experimental results, the proposed method strongly reduced motion blurs arisen from large motions, and yielded interpolated images with high visual performance and peak signal-to-noise ratio (PSNR).

• 한국통신학회논문지
• /
• 제24권7A호
• /
• pp.1046-1051
• /
• 1999

PCCC(Parallel Concatenated Convolutional Codes: 터보 코드)는 블록 크기가 크면 클수록 성능이 우수한 것으로 잘 알려져 있다. 본 논문은 차세대 이동 통신 시스템에서 프레임 크기가 작은 음성/제어 프레임을 이용하여 터보 코드의 성능을 검증하여 보고, 비슷한 디코딩 복잡도에 터보 코드와 컨벌루션 코드의 성능과 시스템에 적용하기 위한 조건들을 고려하였다. 그 결과 터보 코드는 프레임 크기가 작은 조건에서 반복 횟수 3회만으로도 차세대 통신 시스템에 적합한 10-3이상의 좋은 성능을 나타내었다. 그러나, 10-3의 BER을 기준으로 비슷한 복잡도를 고려하였을 때는 부호화율이 1/2인 터보 코드(K = 5)의 성능은 낮은 Eb/N0에서 컨벌루션 코드(K = 9)보다 우수하고, K = 3인 터보 코드의 성능은 K = 7인 컨벌루션 코드보다 우수하였다. 또한 부호화율이 1/3인 경우 K = 3 또는 5인 터보 코드가 부호화율이 1/2인 터보 코드와 비슷한 성능을 나타내었다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 춘계학술대회 논문집
• /
• pp.110-116
• /
• 2002

In this paper, various kinds of A-Frame are surveyed and classified according to their functional ability and sizes. Based on the study, a A-Frame that is suitable for ROV/AUV operation is designed. Basic theoretical structural requirements are applied and relevant Finite Element Analysis are carried out for the verification of the sound workability of the proposed A-Frame. Final configuration and the specification are proposed for the usage of ROV/AUV operation.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 추계학술대회 논문집
• /
• pp.186-190
• /
• 2002

In this paper, various kinds of A-Frame are surveyed and classified according to their functional ability and sizes. Based on the study, a A-Frame that is suitable for ROV/AUV operation is designed. Basic theoretical structural requirements are applied and relevant Finite Element Analysis are earned out for the verification of the sound workability of the proposed A-Frame. Final configuration and the specification are proposed for the usage of ROV/AUV operation.

• 건축역사연구
• /
• 제19권5호
• /
• pp.25-47
• /
• 2010

The purpose of this study is to reconstruct the wooden frame structure of Buddhist temple, Kumdang in Youngamsaji which assumed to be built in the 9th century of Unified Silla Dynasty. The remaining site of Kumdang in Youngamsaji is investigated thoroughly with a particular attention to bay size and column distribution. The five ancient Buddhist temples which were built in the same period also have the same frame type as Youngamsaji Kumdang. These five ancient Buddhist temples and Kumdang in Youngamsaji are meticulously investigated in terms of their bay sizes and measuring modules. The framework schema is devised as a conceptual tool to conjecture wooden frame structures of Buddhist temple. A theoretical differentiation between frame type and frame structure is attempted to formulated a wooden frame structure as a stepping-stone for the reconstruction of traditional wooden building. The wooden frame structure of 9C Kumdang in Youngamsaji mainly follows the oldest Korean wooden pavilion, Muryangsujeon in Busuk temple, with a hip and gable roof. The wooden frame structure of 9C Kumdang in Youngamsaji is reconstructed through 3D computer modeling to such an extent that every wooden components of the structure can be 3D printed. The reconstruction also takes reference from the Cai-Fen system in Yingzao Fashi.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 하계종합학술대회 논문집
• /
• pp.61-64
• /
• 1999

The turbo code appropriate to IMT-2000 is known to have a good performance whenever the size of frame increases. But it is not appropriate to a sort of video service to need real time because of decoding complexity and long delay time by the size of frame. Therefore this paper proposes decoding decision algorithm of short frame in which soft output is weighted according to iteration number in turbo decoder. Performance of the proposed algorithm is analysed in the AWGN channel when short length of frame is 100, 256, 640. As the result. it is appeared that the proposed decoding decision algorithm has improved in BER other than in the existing MAP decoding algorithm.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.384-389
• /
• 2005

The objective on this project is to develop a cooperative Field Robot (FR), by using a customize Open Control Platform (OCP) as design and development process. An OCP is a CORBA-based solution for networked control system, which facilitates the transitioning of control designs to embedded targets. In order to achieve the cooperation surveillance system, two FRs are distributed by navigation messages (GPS and sensor data) using CORBA event-channel communication, while graphical information from IR night vision camera is distributed using CORBA Asynchronous Method Invocation (AMI). The QoS features of AMI in the network are to provide the additional delivery method for distributing an IR camera Images will be evaluate in this experiment. In this paper also presents an empirical performance evaluation from the variable chunk sizes were compared with the number of clients and message latency, some of the measurement data's are summarized in the following paragraph. In the AMI buffers size measurement, when the chuck sizes were change, the message latency is significantly change according to it frame size. The smaller frame size between 256 bytes to 512 bytes is more efficient fur the message size below 2Mbytes, but it average performance in the large of message size a bigger frame size is more efficient. For the several destination, the same experiment using 512 bytes to 2 Mbytes frame with 2 to 5 destinations are presented. For the message size bigger than 2Mbytes, the AMI are still able to meet requirement far more than 5 clients simultaneously.

• Journal of Mechanical Science and Technology
• /
• 제18권7호
• /
• pp.1236-1245
• /
• 2004

In this study, an optical imaging method was developed for the measurements of the sizes and velocities of droplets in sprays. Double-exposure single-frame spray images were captured by the imaging system. An image processing program was developed for the measurements of the sizes and positions of individual particles including separation of the overlapped particles and particle tracking and pairing at two time instants. To recognize and separate overlapping particles, the morphological method based on watershed segmentation as well as separation using the perimeter and convex hull of image was used consecutively. Better results in separation were obtained by utilization of both methods especially for the multiple or heavily-overlapped particles. The match probability method was adopted for particle tracking and pairing after identifying the positions of individual particles and it produced good matching results even for large particles like droplets in sprays. Therefore, the developed optical imaging method could provide a reliable way of analyzing the motion and size distribution of droplets produced by various sprays and atomization devices.

• 한국통신학회논문지
• /
• 제32권11C호
• /
• pp.1066-1072
• /
• 2007

본 논문에서는 동영상 부호화 방식의 움직임 추정을 위한 고속 다중 참조 프레임 선택 기법에 대해 제안한다. 움직임 추정을 위해 다중 프레임을 참조하는 H.264 동영상 부호화 방식의 경우, 블록별로 선택된 최적의 참조 프레임들은 일정한 상관관계를 유지하는 특성이 존재한다. 제안 방식은 이러한 통계적 특성을 이용하여, 임의의 블록 크기의 움직임 추정 모드에서 선택된 최적의 참조 프레임 정보를 이용하여 하위 블록 크기의 움직임 추정 모드에서 사용할 참조 프레임을 예측한다. 실험 결과를 통해 5개의 참조 프레임 사용을 기준으로 제안하는 기법을 사용하였을 때, 움직임 추정에 소요되는 시간은 가용한 모든 참조 프레임에 대해 움직임 추정을 수행하는 방식 대비 평균 60% 감소되었으며, PSNR 및 발생 비트율 측면에서 거의 동일한 성능을 유지함을 확인할 수 있었다.