• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1631-1639
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• 2010

This paper proposes a scheduling algorithm that can reduce the power consumed for execution of application programs and the communication cost incurred due to dependencies among tasks. The proposed scheduling algorithm can increase energy efficiency of the DVS(Dynamic Voltage Scaling) by estimating laxity usage during scheduling, making up for conventional algorithms that apply the DVS after scheduling. Energy efficiency can be increased by applying the proposed algorithm to complex multimedia applications. Experimental results show that energy consumptions for executing HD MPEG4, MotionJPEG codec, MP3, and Wavelet have been reduced by 11.2% on the average, when compared to conventional algorithms.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.323-326
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• 1998

본 논문에서는 한국통신에서 음성인식을 이용한 전화정보 서비스의 일환으로 개발해 온 증권정보 시스템의 구조와 기능을 설명하고, 시스템을 다채널로 확장함에 있어서 시스템의 자원을 효율적으로 활용하기 위하여 적용한 방법에 대하여 기술하였다. 이 시스템에서는 음성특징을 추출하는 프로세서(DSP0)들과 단억검색을 하는 프로세서(DSP1)들이 분리되어 있으며, 이 둘 간의 개수 비율을 조절함으로써 실시간적 처리 효과를 유지하면서도 시스템의 전체 프로세서의 개수를 줄였다. DSP0와 DSP1 간의 음성 특징 데이터 전송에 있어서는 DSP0에서 발생하는 데이터를 음성이 입력되는 중에 전송할 수 있게 함으로써, DSP1에서는 DSP0과 병렬적으로 작업을 수행시킬 수 있으며, 결과적으로 시스템의 속도를 빠르게 하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1107-1111
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• 2005

The DVR system realization with watermarking and MPEG-4 for real time processing speed improvement is presented in this paper. For the real time processing the system is used the DSP processor, Quick DMA for data transmission, watermarking for security and MPEG-4 compression for facility. The algorithms are that the operational structure has the internal memory of processor, and the optimal realization is suitable to form the DSP processor structure r processed for the iterative operations. The experimental result shows the real time processing is improved 12% over for the D1 image in comparison with the other system.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.691-693
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• 2005

In a sender-initiated load balancing algorithm, a sender continues to send unnecessary request messages for load transfer until a receiver is found while the system load is heavy. Therefore, it yields many problems such as low cpu utilization and system throughput because of inefficient inter-processor communications until the sender receives an accept message from the receiver in this environment. This paper presents an approach based on evolutionary algorithm. The processors to which the requests are sent off are determined by the proposed algorithm to decrease unnecessary request messages.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1338-1340
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• 2003

현재의 공장 자동화, 국방, 항공, 철도, 금융 등을 포함하는 실시간 시스템은 여러 개의 컴퓨터가 다수의 장소에서 서로의 데이터 교환을 통한 협동 작업으로 여러 가지 기능 및 업무를 수행한다. 이는 마치 멀티프로세서를 가진 컴퓨터같이 생각할 수 있으며 이와같은 시스템에 있어서 업무 수행의 효율은 각 프로세서의 계산 능력에 비례함과 동시에 각 노드간의 데이터 전송 능력에 비례한다고 할 수 있다. 이와 같은 실시간 시스템이 올바르게 동작하기 위해서는 한정된 시간 내에 일정한 양의 데이터의 전달을 확정적으로 보장해 줄 수 있는 네트워크를 필요로 하는데 이를 실시간 네트워크(Real time network)라고 한다. 현대의 분산제어 시스템에 있어서 확정적인 시간 내의 데이터 전달은 전체 제어 시스템의 응동 특성에 중요한 요인이 된다. 본 논문은 한국형 고속 전철의 시제차(Prototype train)에 적용된 국제 표준 실시간 네트워크인 열차 통신 네트워크(Train Communication Network)에 관련한 내용이다. 실시간 네트워크는 실시간성을 보장하기 위해서 상호 교환될 데이터가 필요에 따라(온라인 상에서) 변경되는 것이 아니라 오프라인 디자인의 결과로 미리 결정되어진다. 즉 통신장치 사이에 전달되는 네트워크 데이터는 미리 설계된 네트워크 테이블을 기초로 정해진 시간에, 정해진 데이터가, 정해진 방식으로 전달되어 진다. 본 논문에서는 실시간 네트워크의 오프라인 설계를 하기 위한 도구로서 개발되어진 네트워크 데이터 테이블 작성 프로그램에 대해서 설명한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1545-1550
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• 2006

In this paper, we propose a method for applying the CLEAN algorithm to an minimum variance distortionless response(MVDR) to estimate the location of multiple targets distributed in the ocean. The CLEAN algorithm is easy to implement in a linear processor, yet not in a nonlinear processor. In the proposed method, the CSDM of a Dirty map is separated into the CSDM of a Clean beam and the CSDM of the Residual, then an individual ambiguity surface(AMS) is generated. As such, the CLEAN algorithm can be applied to an MVDR, a nonlinear processor. To solve the ill-conditioned problem related to the matrix inversiion by an MVDR when using the CLEAN algorithm, Singular value decomposition(SVD) is carried out, then the reciprocal of small eigenvalues is replaced with zero. Experimental results show that the proposed method improves the performance of an MVDR.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.441-443
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• 2011

OSEK COM은 OSEK/VDX에서 제안한 자동차 ECU의 태스크 간 통신 규약이다. 본 논문에서는 OSEK COM의 규약을 준수하는 내부 통신을 위한 메시지 송수신 메커니즘을 제시한다. 제시한 메커니즘의 타당성을 검토하기 위하여 ARM 프로세서가 탑재된 EZ-AT7에서 태스크 간의 정상적인 내부 통신 동작 상태를 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.29 no.3
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• pp.191-199
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• 2010

Physical modeling is a synthesis method of high quality sound which is similar to real sound for musical instruments. However, since physical modeling requires a lot of parameters to synthesize sound of a musical instrument, it prevents real-time processing for the musical instrument which supports a large number of sounds simultaneously. To solve this problem, this paper proposes a single instruction multiple data (SIMD) parallel processor that supports real-time processing of sound synthesis of guitar, a representative plucked string musical instrument. To control six strings of guitar, we used a SIMD parallel processor which consists of six processing elements (PEs). Each PE supports modeling of the corresponding string. The proposed SIMD processor can generate synthesized sounds of six strings simultaneously when a parallel synthesis algorithm receives excitation signals and parameters of each string as an input. Experimental results using a sampling rate 44.1 kHz and 16 bits quantization indicate that synthesis sounds using the proposed parallel processor were very similar to original sound. In addition, the proposed parallel processor outperforms commercial TI's TMS320C6416 in terms of execution time (8.9x better) and energy efficiency (39.8x better).

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.1
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• pp.93-102
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• 2000

Processors for a base station controller such as call control processor have to serve usersdemand. Some of processors have been still used for the processing of call and 0&M (operation and maintenance) management by adopting embedded board type. This type can not provide users with a wide variety of environments for testing and debugging. User environments are regarded as a primary system factor in most systems and this is particularly so in designing and implementing the processor for base station controller in mobile communication systems. We describe the design and implementation of new user environment tool named QUEST for the next generation mobile communication system, IMT-2000. The simulation results of performance evaluations demonstrate that our system performs well for a base station controller without performance degradation.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.2
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• pp.38-46
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• 2001

This paper presents a new multiprocessor system and corresponding scheduling algorithm that can be applied for implementation of fine grain DSP algorithms such as digital filters. The newly proposed system uses one or more shared buses as the basic interconnection network between processors, and fixed amount of clock-skew is maintained between instruction execution of processors. This system not only can handle the interprocessor communications very efficiently but also can explicitly incorporate the interprocessor communication delay time into the multiprocessor scheduling model. This paper also presents a new scheduling strategy for implementing digital filters expressed in fully-specified flow graphs on the proposed system. The simulation result shows that well-known digital filters can be implemented on proposed multiprocessor in which the implementation satisfies the iteration period bound.