• Title/Summary/Keyword: dynamic memory allocation

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Dynamic Buffer Allocation Scheme for Caching in Realtime Multimedia Systems (실시간 멀티미디어 시스템에서의 캐슁을 위한 동적 버퍼 할당 기법)

  • Kwon, Jin-Baek;Yeom, Heon-Young;Lee, Kyung-Oh
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.4
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    • pp.420-430
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    • 2000
  • Several caching schemes for realtime multimedia systems have been proposed, but they focus only on increasing the hit ratio without providing any means to utilize the saved disk bandwidth due to cache hits. One of the most important metrics in multimedia systems is the number of clients that the systems can service simultaneously guaranteeing Quality of Service(QoS). Preemptive but Safe Interval Caching(PSIC) was proposed as a caching scheme which makes it possible to provide deterministic QoS.. However, it has no ability to adapt to the change of system environments since it has no mechanism to change the cache size. In this paper, we present a new caching scheme, Dynamic Interval Caching(DIC), which maximizes the performance, regardless of the change of system environments, providing hiccup-free service, by managing memory buffers dynamically. And it is demonstrated that DIC allocates buffer cache optimally, by comparing with PSIC through trace-driven simulations.

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A Multi-Dimensional Thermal-Hydraulic System Analysis Code, MARS 1.3.1

  • Jeong, Jae-Jun;Ha, Kwi-Seok;Chung, Bub-Dong;Lee, Won-Jae
    • Nuclear Engineering and Technology
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    • v.31 no.3
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    • pp.344-363
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    • 1999
  • A multi-dimensional thermal-hydraulic system analysis code, MARS 1.3.1, has been developed in order to have the realistic analysis capability of two-phase thermal-hydraulic transients for pressurized water reactor (PWR) plants. As the backbones for the MARS code, the RELAP5/MOD3.2.1.2 and COBRA-TF codes were adopted in order to take advantages of the very general, versatile features of RELAP5 and the realistic three-dimensional hydrodynamic module of COBRA-TF. In the MARS code, all the functional modules of the two codes were unified into a single code first. Then, the source codes were converted into the standard Fortran 90, and then they were restructured using a modular data structure based on "derived type variables" and a new "dynamic memory allocation" scheme. In addition, the Windows features were implemented to improve user friendliness. This paper presents the developmental work of the MARS version 1.3.1 including the hydrodynamic model unification, the heat structure coupling, the code restructuring and modernization, and their verifications.their verifications.

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A Study on Implementation of On-Line Gaming Server applying an Object Polling Scheme (객체폴링기법을 적용한 온라인 게임서버의 구현에 관한 연구)

  • Kim, Hye-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.19-24
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    • 2009
  • When a dynamic method is applied at the time of occurrence of an client's connection request for most of the online gaming server engine, the gaming server is processing a session connection, it's initialization. Yet, such a method will cause a lot of loading and bottle-neck in the gaming server at the same time. Therefore we propose the object polling scheme to minimizes a memory fragmentation and loading of the initialization on the client using a static allocation method for an efficient On-lin gaming serverin this paper. We implement the gaming server applying to our proposed scheme, and we show an improvement in our proposed scheme by performance analysis in this paper.

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Design of a Rule-Based Solution Based on MFC for Inspection of the Hybrid Electronic Circuit Board (MFC 기반 하이브리드 전자보오드 검사를 위한 규칙기반 솔루션 설계)

  • Ko Yun-Seok
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.9
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    • pp.531-538
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    • 2005
  • This paper proposes an expert system which is able to enhance the accuracy and productivity by determining the test strategy based on heuristic rules for test of the hybrid electronic circuit board producted massively in production line. The test heuristic rules are obtained from test system designer, test experts and experimental results. The guarding method separating the tested device with circumference circuit of the device is adopted to enhance the accuracy of measurements in the test of analog devices. This guarding method can reduce the error occurring due to the voltage drop in both the signal input line and the measuring line by utilizing heuristic rules considering the device impedance and the parallel impedance. Also, PSA(Parallel Signature Analysis) technique Is applied for test of the digital devices and circuits. In the PSA technique, the real-time test of the high integrated device is possible by minimizing the test time forcing n bit output stream from the tested device to LFSR continuously. It is implemented in Visual C++ computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the interface with the electronic circuit database and the hardware direct control. Finally, the effectiveness of the builded expert system is proved by simulating the several faults occurring in the mounting process the electronic devices to the surface of PCB for a typical hybrid electronic board and by identifying the results.

A Real-Time Expert System for the High Reliability of Railway Electronic Interlocking System (철도 전자연동장치의 고신뢰화를 위한 실시간 전문가 시스템)

  • Go, Yun-Seok;Choe, In-Seon;Gwon, Yong-Hun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.11
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    • pp.1457-1463
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    • 1999
  • This paper develops an real-time expert system for the electronic interlocking system. it obtains the higher safety by determining the railway interlocking strategy in order to prevent trains from colliding, and derailing in the viewpoint of veteran expert, considering the situation of station in real-time. The expert system determines the real-time interlocking strategy by confirming the interlocking relationships among signal facilities based on the interlocking knowledge base from input information such as signal, points, and it is implemented as the rule-based system in order to represented accurately and effectively the interlocking relationships. Especially in case of emergency the function which determines the rational route coordinating with IIKBAG on the workstation is designed in order to minimize the spreading effect. It is implemented in C computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the build and interface of the station structure database. And, the validity of the built expert system is proved by simulating the diversity cases which may occur in the real system for the typical station model.

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Design of Operating System for Wireless Sensor Nodes with Enhanced Remote Code Update Functionality (원격 코드 업데이트가 가능한 무선 센서 노드용 운영체제)

  • Kim, Chang-Hoon;Cha, Jeong-Woo;Kim, Il-Hyu
    • Journal of Korea Society of Industrial Information Systems
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    • v.16 no.1
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    • pp.37-48
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    • 2011
  • Sensor networks monitor the environment, collect sensed data, and relay the data back to a collection point. Although sensor nodes have very limited hardware resources, they require an operating system that can provide efficient resource management and various application environments. In addition, the wireless sensor networks require the code update previously deployed to patch bugs in program and to improve performance of kernel service routines and application programs. This paper presents EPRCU (Easy to Perform Remote Code Update), a new operating system for wireless sensor nodes, which has enhanced functionalities to perform remote code update. To achieve an efficient code update, the EPRCU provides dynamic memory allocation and program memory management. It supports the event-driven kernel, which uses priority-based scheduling with the application of aging techniques. Therefore, the proposed operating system is not only easy to perform wireless communication with the remote code update but also suitable for various sensor network applications.

A Study on the Knowledge-Based T.P.N. System (1) (지식 구조화 경정맥 완전 영양공급 시스템의 개발에 관한 연구 (I))

  • Jeon, Gye-Rok;Choe, Sam-Gil;Byeon, Geon-Sik
    • Journal of Biomedical Engineering Research
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    • v.11 no.2
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    • pp.305-314
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    • 1990
  • In this paper we have implemented and tested TPN which is system to supply sufficent nutrition to nutritionally deficient patient by means of ES (expert system) a kind of A.1 (artificial intelligence) . This system affords to evaluation of nutritional state of patient which is essential to physi- cian. who performs TPN, decision of performing TPN and management of patient-data & calculation of information needing to making TPN fluid. The features were as follolv 1. we input data, take ideal weight of patient and 24hr's creatlnln In urine according to chart in system compare TSF (triceps skin fold), MAC (mid-arm circumference), AMC (arm muscle circumference) to 5th, 15th, 50th percentile and evaluate the nutritional state of patient. 2. Calculation of protein & nonprotein calorie needing to treament of patient can be made exactly by stress factor, activity factor and body temperature. 3. patient's personal recording needing to management of patient date name of chief doc- tor, name of department of admission, chart number, history can by taken very easily. 4. The way of system operating is pull-down Menu one, It can be processing very efficiently. 5. Date processing in system, we can manage memory volume of computer verlr efficiently using of dynamic allocation variables. 6. We can make it very easy to edit & revise the input data, processed data is saved to diskette in 2 files (TDF, THF) , these are semipermanent preservation.

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The Item Distribution Method for the Party System in the MMORPG Using the Observer Pattern (Observer 패턴을 적용한 MMORPG의 파티 시스템 아이템 배분 방법)

  • Kim, Tai-Suk;Kim, Shin-Hwan;Kim, Jong-Soo
    • Journal of Korea Multimedia Society
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    • v.10 no.8
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    • pp.1060-1067
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    • 2007
  • We need various methods to develop MMORPG that is game genre which many users use among various game genre using Internet. Specially, to heighten efficiency of distributing work, Object-oriented language such as C++ is used and we need design techniques that can take advantage of enough object-oriented concept when making large-scale game. There is various pattern that can apply in software breakup design in GoF's design pattern for these design techniques. If you apply Observer pattern to Party System Design for forming community between game users, you can easily add new class and maintain system later. Party Play is one of the important system that is used to form game users' community in MMORPG games. The main point that must be considered in Party-Play-System is to divide evenly experience value and acquisition that is got by Party-Play among users according to each user's level. To implement Party Play System that consider maintenance of system, in this paper, we propose a method using GoF's Observer-Pattern, showing you that proposed method which has advantage to dynamic memory allocation and to virtual method call can be used usefully to change object to real time at program run and to add new class and to maintain system new.

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