• 한국멀티미디어학회논문지
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• 제10권9호
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• pp.1197-1208
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• 2007

오늘날 대부분의 스마트카드는 자바카드 플랫폼을 채택한 자바카트가 표준안으로 자리매김 하고 있다. 자바카드 기술은 이식성, 플랫폼 독립성, 높은 보안성 기능을 스마트카드에 제공한다. 그러나 자바카드는 일반 스마트카드에 비해 자바 언어 상의 특성으로 인해 실행속도 저하의 단점을 갖고 있다. 실행속도에 영향을 끼치는 요소는 자바 카드가 데이터를 저장하는 방식과 자바카드 설치기가 애플릿을 설치하는 방식 때문이다. 본 논문에서는 자바카드 프로그램의 적재와 실행의 속도를 개선시키기 위한 방안으로 자바카드에서 EEPROM에 데이터에 대한 저장, 갱신, 삭제하는 과정들을 처리 속도가 빠른 RAM을 이용하여 자바카드의 속도를 개선할 수 있다. 이를 위해 자바카드에서 RAM을 활용한 방법으로 자바카드 환경에 맞는 선반입 LRU-OBL 버퍼 캐쉬 기법을 제시한다. 자바카드에서 생성되는 모든 데이터들을 데이터 특성에 따라 버퍼 캐쉬에서 관리함으로써 EEPROM에 대한 기록 횟수를 최대한 줄여 자바카드의 프로그램 적재 및 실행속도를 향상시킨다.

• 정보교육학회논문지
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• 제23권2호
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• pp.107-116
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• 2019

본 연구는 초등학생의 논리적 사고력 신장을 위한 교육 방법으로 수행시간 중심의 파이썬 정렬 알고리즘 교육 프로그램을 개발하여 적용한 후 그 효과를 검증하였다. 교육 프로그램은 현직 초등학교 교사 100명을 대상으로 실시한 사전 요구 분석 결과를 바탕으로 하여 개발하였다. 개발한 교육 프로그램의 효과를 검증하기 위해 ${\bigcirc}{\bigcirc}$ 대학교에서 실시한 초등학생 교육기부 프로그램의 지원자 표집에 의한 지원자 표본 25명을 대상으로 6일간 1일 7차시씩 42차시를 진행하였다. 한국교육개발원에서 개발한 '논리적 사고 검사(GALT)'를 활용하여 사전 사후 검사 결과를 통해 교육적 효과를 분석하였으며, 분석 결과 수행시간 중심의 파이썬 정렬 알고리즘교육이 초등학생의 논리적 사고력 향상에 효과적인 것으로 나타났다.

• Journal of Electrical Engineering and information Science
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• 제2권6호
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• pp.183-190
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• 1997

We present competition protocols to speed up the execution of sequential programs on a network of shared workstations in the background by exploiting their wasted computing capacity, without interfering with processes of workstation owners. In order to argue that competition protocols are preferable to migration protocols in this situation, we derive the closed form solutions for the speedup of competition protocols and migration protocols, and simulate both of protocols under comparable overhead assumptions. Based on our analytic results and simulation results, we show that competitive execution is superior to process migration, and that competitive execution can finish sequential programs significantly faster than noncompetitive execution, especially when the foreground load is sufficiently high.

• 정보처리학회논문지A
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• 제13A권6호
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• pp.533-540
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• 2006

본 논문에서는 분산 환경 상에서 CFD(Computational Fluid Dynamics) 분석 프로그램을 편리하게 수행할 수 있도록 하는 그리드 시스템 META(Metacomputing Environment using Test-un of Application)의 설계 및 구현에 관하여 기술한다. 그리드 시스템 META는 CFD 프로그램 개발자들이 네트워크에 분산된 계산 자원들을 단일 시스템처럼 사용할 수 있도록 한다. 그리드 컴퓨팅과 관련하여 연구주제로는 고장허용, 자원 선택, 사용자 인터페이스 설계 등이 있다. 본 논문에서는 MPI(Message Passing Interface)로 작성된 SPMD(Single Program, Multiple Data) 구조의 병렬프로그램을 실행시키기 위한 자동 자원 선택방법을 활용하였다. 본 논문에서 제안한 자원 관리기법은 네트워크상의 전송지연 시간과 시험수행을 통해 얻어진 핵심루프의 경과시간을 이용한다. 전송지연시간은 병렬 프로그램이 복수의 시스템에 분산되어 수행될 때 수행 성능에 큰 영향을 주는 요인이다. CFD 프로그램들의 공통적인 특성 때문에 핵심루프 경과시간은 전체 수행시간을 예측할 수 있는 지표가 된다. 핵심루프는 CFD 프로그램의 전체 수행시간 중 90% 이상을 차지한다.

• 전자공학회논문지B
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• 제33B권4호
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• pp.148-155
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• 1996

A loop structure optimization algorithm is proposed for generting a set of efficient codes for loop structure in order to optimize RISC compiler codes. Since there are so many loop structure in the program, most of the execution time is used to process looping codes. Thus, reduction of loop instructions is more effective than optimizing codes outside the loop. The proposed algorithm presents a method to combine several different loops into a simple loop. Therefore, rather than executing each loop independently, loops in the program are serached, analyzed, and finally created some relative informtion such as dependency and range. In doing so, the loops in the program can efficiently be recombined and restructured. As a result, the overall execution time for the program of the sequential programming language is reduced.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.176-179
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• 2002

In recent years, an increasing amount of computer network research has focused on the problem of cluster system in order to achieve higher performance and lower cost. The load unbalance is the major defect that reduces performance of a cluster system that uses parallel program in a form of SPMD (Single Program Multiple Data). Also, the load unbalance is a problem of MPP (Massive Parallel Processors), and distributed system. The cluster system is a loosely-coupled distributed system, therefore, it has higher communication overhead than MPP. Dynamic load balancing can solve the load unbalance problem of cluster system and reduce its communication cost. The cluster systems considered in this paper consist of P heterogeneous nodes connected by a switch-based network. The master node can predict the average execution time of tasks for each slave node based on the information from the corresponding slave node. Then, the master node redistributes remaining tasks to each node considering the predicted execution time and the communication overhead for task migration. The proposed dynamic load balancing uses execution time prediction to optimize the task redistribution. The various performance factors such as node number, task number, and communication cost are considered to improve the performance of cluster system. From the simulation results, we verified the effectiveness of the proposed dynamic load balancing algorithm.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.162-169
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• 2022

Arduino is used in various places such as education, experimentation, and industry. Due to the easy accessibility of Arduino, it is often used by non-majors, and it is also used in media art and toy programs. Although Arduino is relatively easy to use compared to other devices, it is not easy to control various IoT components at the same time. Some tasks run independently of other tasks, while others run dependently. In this paper, I proposed the Arduino Task Framework to efficiently execute many tasks in these various situations. The design framework of this paper is largely composed of two types: synchronous execution and asynchronous execution. These two execution methods can be combined to create several independent and dependent execution routines. Asynchronous tasks are independently executed tasks and are managed by AsyncTaskGroup, while synchronous tasks are dependently executed tasks and are managed by SyncTaskGroup. AsyncTaskGroup instance and SyncTaskGroup instance are instances of the same Task and can be used in combination with another task. The Arduino framework proposed in this paper simplifies the program structure and can easily compose various tasks.

• 대한임베디드공학회논문지
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• 제14권2호
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• pp.103-111
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• 2019

The IoT-driven large-scaled systems consist of connected things with on-chip executable embedded software. These light-weighted embedded things have limited hardware space, especially small size of on-chip flash memory. In addition, on-chip embedded software in flash memory is not easy to update in runtime to equip with latest services in IoT-driven applications. It is becoming important to develop light-weighted IoT devices with various software in the limited on-chip flash memory. The remote instruction execution in cloud via IoT connectivity enables to provide high performance software execution with unlimited software instruction in cloud and low-power streaming of instruction execution in IoT edge devices. In this paper, we propose a Cloud-IoT asymmetric structure for providing high performance instruction execution in cloud, still low power code executable thing in light-weighted IoT edge environment using remote instruction execution. We propose a simulated approach to determine efficient partitioning of software runtime in cloud and IoT edge. We evaluated the instruction cloudification using remote instruction by determining the execution time by the proposed structure. The cloud-connected instruction set simulator is newly introduced to emulate the behavior of the processor. Experimental results of the cloud-IoT connected software execution using remote instruction showed the feasibility of cloudification of on-chip code flash memory. The simulation environment for cloud-connected code execution successfully emulates architectural operations of on-chip flash memory in cloud so that the various software services in IoT can be accelerated and performed in low-power by cloudification of remote instruction execution. The execution time of the program is reduced by 50% and the memory space is reduced by 24% when the cloud-connected code execution is used.

• International Journal of Computer Science & Network Security
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• 제23권10호
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• pp.49-56
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• 2023

Computer architecture serves as a link between application requirements and underlying technology capabilities such as technical, mathematical, medical, and business applications' computational and storage demands are constantly increasing. Machine learning these days grown and used in many fields and it performed better than traditional computing in applications that need to be implemented by using mathematical algorithms. A mathematical algorithm requires more extensive and quicker calculations, higher computer architecture specification, and takes longer execution time. Therefore, there is a need to improve the use of computer hardware such as CPU, memory, etc. optimization has a main role to reduce the execution time and improve the utilization of computer recourses. And for the importance of execution time in implementing machine learning supervised module linear regression, in this paper we focus on optimizing machine learning algorithms, for this purpose we write a (Diabetes prediction program) and applying on it a Practical Swarm Optimization (PSO) to reduce the execution time and improve the utilization of computer resources. Finally, a massive improvement in execution time were observed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.715-718
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• 2000

Although shared memory parallel programs are designed to be deterministic both in their final results and intermediate states, the races that occur when different processes access a common memory location in an order not guaranteed by synchronization could result in unintended non-deterministic executions of the program. So, Detecting races, particularly first data races, is important for debugging explicit shared memory parallel programs. It is possible that all data races reported by other on-the-fly algorithms would disappear once the first races were removed. To detect races parallel programs with nested loops and inter-thread coordination, it must guarantee the order of synchronization operations in an execution instance. In this paper, we propose an improved restructuring method that guarantee ordering execution instance and preserve the semantics of original program. This method requires O(np) time and (s + up) space, where n is the number of total operations, s is the number of synchronization operations and p is the number of parallelism in the execution. Also, this method makes on-the-fly detection of parallel program with nested loops and inter-thread coordination more easily in space and time complexity.