• Title/Summary/Keyword: Process scheduling algorithm

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조선 중일정계획시스템을 위한 공정계획 객체 설계에 관한연구

  • 최해주;박주철
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.290-293
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    • 2001
  • The mid-schedule planning of the ship is making a schedule about the process from cutting to erection. The ship consists of lots of blocks. This block has different process because of the shape of the block varies in accordance with the ship-type and the part position of the ship. The type and order of each block process initially must be generated for the mid-schedule planning. In this paper, the process planning, described as above is preparing the basic information before scheduler make a plan with the prepared manhour. The scheduling is done with this process planning which includes the information of the process order. This paper shows the research about three methods to design the process planning. First, investigate the expression method about information of the process planning for the mid-schedule planning in real workplace. Second, design the object of the process planning on the basis of investigating the expression method. Finally, develop the prototype of object on the basis of this designed process planning and then find the practical use in the mid-schedule planning. The object, which is developed in this paper, contains the main algorithm. In case of developing The Mid-Schedule Planning System, this object is expected to be utilized very easily as consisting another object.

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Scheduling of Parallel Offset Printing Process for Packaging Printing (패키징 인쇄를 위한 병렬 오프셋 인쇄 공정의 스케줄링)

  • Jaekyeong, Moon;Hyunchul, Tae
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.3
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    • pp.183-192
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    • 2022
  • With the growth of the packaging industry, demand on the packaging printing comes in various forms. Customers' orders are diversifying and the standards for quality are increasing. Offset printing is mainly used in the packaging printing since it is easy to print in large quantities. However, productivity of the offset printing decreases when printing various order. This is because it takes time to change colors for each printing unit. Therefore, scheduling that minimizes the color replacement time and shortens the overall makespan is required. By the existing manual method based on workers' experience or intuition, scheduling results may vary for workers and this uncertainty increase the production cost. In this study, we propose an automated scheduling method of parallel offset printing process for packaging printing. We decompose the original problem into assigning and sequencing orders, and ink arrangement for printing problems. Vehicle routing problem and assignment problem are applied to each part. Mixed integer programming is used to model the problem mathematically. But it needs a lot of computational time to solve as the size of the problem grows. So guided local search algorithm is used to solve the problem. Through actual data experiments, we reviewed our method's applicability and role in the field.

Development of a Real-time Communication Service over Random Medium Access Scheme Networks

  • Choo, Young-Yeol;Kwon, Jang-Woo
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.350-353
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    • 2004
  • The increasing use of Ethernet-TCP/IP network in industry has led to the growing interest in its reliability in real-time applications such as automated manufacturing systems and process control systems. However, stochastic behavior of its medium access scheme makes it inadequate for time-critical applications. In order to guarantee hard real-time communication service in Ethernet-TCP/IP network, we proposed an algorithm running over TCP/IP protocol stack without modification of protocols. In this paper, we consider communication services guaranteeing deadlines of periodic real-time messages over MAC protocols that have unbounded medium access time. We propose a centralized token scheduling scheme for multiple access networks. The token is used to allow a station to transmit its message during the time amount that is appended to the token. The real-time performance of the proposed algorithm has been described.

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A Low Poorer Resource Allocation Algorithm Based on Minimizing Switching Activity (스위칭 동작 최소화를 통한 저 전력 자원할당 알고리즘)

  • 신무경;인치호;김희석
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.121-124
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    • 2001
  • This paper proposed resource allocation algorithm for the minimum switching activity of functional unit in high level synthesis process as like DSP which is circuit to give many functional unit. The resource allocation method after scheduling use the power function calculating average hamming distance and switching activity of the between two input. First of all, the switching activity is calculated by the input value after calculating the average hamming distance between operation. In this paper, the proposed method though high If level simulation find switching activity in circuit each functional unit exchange for binary sequence length and value bit are logic one value. To use the switching activity find the allocation with minimal power consumption, the proposed method visits all control steps one by one and determines the allocation with minimal power consumption at each control step. As the existing method, the execution time can be fast according to use the number of operator and max control step. And it is the reduction effect from 6% to 8%.

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A RTL Binding Technique and Low Power Technology Mapping consider CPLD (CPLD를 고려한 RTL 바인딩과 저전력 기술 매핑)

  • Kim Jae-Jin;Lee Kwan-Houng
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.2 s.40
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    • pp.1-6
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    • 2006
  • In this paper, a RTL binding technique and low power technology mapping consider CPLD is proposed. Allocation processing selected module consider the module calculation after scheduling process for circuit by HDL. Select CPLD for constrain after allocation. A Boolean equation is partitioned for CLB by allocated modules. The proposed binding algorithm is description using optimum CLB within a CPLD consider low power. The proposed algorithm is examined by using 16 bit FIR filter. In the case that applicate the algorithm, the experiments results show reduction in the power consumption by 43% comparing with that of non application algorithm.

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An Efficient Implementation of AES Encryption Algorithm for CCTV Image Security (CCTV 영상보안 위한 AES 암호 알고리듬의 효율적인 구현)

  • Kang, Min-Sup
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.2
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    • pp.1-6
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    • 2021
  • In this paper, an efficient implementation of AES encryption algorithm is presented for CCTV image security using C# language. In this approach, an efficient S-Box is first designed for reducing the computation time which is required in each round process of AES algorithm, and then an CCTV image security system is implemented on the basis of this algorithm on a composite field GF(((22)2)2). In addition, the shared S-Box structure is designed for realizing the minimized memory space, which is used in each round transformation and key scheduling processes. Through performance evaluation, it was confirmed that the proposed method is more efficient than the existing method. The proposed CCTV system in C# language using Visual studio 2010.

Generation of Erection Sequence in Shipbuilding Process Planning (조선 공정계획에서 탑재 순서 생성)

  • Hong, Yoon-Gee;Jung, Eun-Kyung;Jun, Jin;Kim, Se-Young
    • IE interfaces
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    • v.10 no.1
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    • pp.189-207
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    • 1997
  • This paper explains a way of describing the erection sequence using the connecting relationship among blocks of a hull in shipbuilding industry. The information of the adjacent blocks such as upper, lower, right, left, front, rear, and their erection status, etd., is defined and the proper use of this allows us to determine one of the possible erection sequences. The methodology suggested also includes some useful benefits of avoiding insert blocks or maintaining stability in erection process. Further, an algorithm for generating the initial erection network is shown and this network may be a basis for designing daily erection scheduling. Some examples illustrate the procedure developed in this study and the results support the model's fidelity.

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Effective Scheduling) Algorithm of Process for Real Time Operating System (실시간 운영체제를 위한 프로세스의 효율적인 스케줄링 알고리즘)

  • 정선아;이지영
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.373-375
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    • 2002
  • 본 논문은 실시간 운영체제에서 프로세스의 효율적인 관리를 위한 스케줄링 알고리즘을 제안한다. 따라서 CPU의 활용도를 높이고 스케줄링 시간과 인터럽트 시간을 줄임으로서 자원을 효율적으로 관리할 수 있다. 본 논문에서 제안하는 방법으로는 다중 큐에 PIT(Process Information Table)를 두어 각각의 큐에 프로세스가 들어오면 우선순위에 따라 CPU를 할당하는 방법이다. 기존의 다중 큐와는 달리 우선순위 프로세스를 보다 정확하고 빨리 찾아내어 외부 또는 내부의 인터럽트에 응답 할 수 있게 하였다. 또한 우선순위에 밀려 실행하지 못하는 프로세스는 일정 시간이 경과하면 CPU를 선점할 수 있다. 그러므로 CPU는 활용도가 높아지고 유휴 시간은 짧아지게 된다. 본 논문은 일반 펜티엄 PC에서 실험하였으며 현재 사용되는 RTOS(VxWorks, QNX)와 비교하여 다소 우수함을 보였다.

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Two-dimensional DCT arcitecture for imprecise computation model (중간 결과값 연산 모델을 위한 2차원 DCT 구조)

  • 임강빈;정진군;신준호;최경희;정기현
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.9
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    • pp.22-32
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    • 1997
  • This paper proposes an imprecise compuitation model for DCT considering QOS of images and a two dimensional DCT architecture for imprecise computations. In case that many processes are scheduling in a hard real time system, the system resources are shared among them. Thus all processes can not be allocated enough system resources (such as processing power and communication bandwidth). The imprecise computtion model can be used to provide scheduling flexibility and various QOS(quality of service)levels, to enhance fault tolerance, and to ensure service continuity in rela time systems. The DCT(discrete cosine transform) is known as one of popular image data compression techniques and adopted in JPEG and MPEG algorithms since the DCT can remove the spatial redundancy of 2-D image data efficiently. Even though many commercial data compression VLSI chips include the DCST hardware, the DCT computation is still a very time-consuming process and a lot of hardware resources are required for the DCT implementation. In this paper the DCT procedure is re-analyzed to fit to imprecise computation model. The test image is simulated on teh base of this model, and the computation time and the quality of restored image are studied. The row-column algorithm is used ot fit the proposed imprecise computation DCT which supports pipeline operatiions by pixel unit, various QOS levels and low speed stroage devices. The architecture has reduced I/O bandwidth which could make its implementation feasible in VLSI. The architecture is proved using a VHDL simulator in architecture level.

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Stochastic Upper Bound for the Stationary Queue Lengths of GPS Servers

  • Kim, Sung-Gon
    • The Korean Journal of Applied Statistics
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    • v.22 no.3
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    • pp.541-551
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    • 2009
  • Generalized processor sharing(GPS) service policy is a scheduling algorithm to allocate the bandwidth of a queueing system with multi-class input traffic. In a queueing system with single-class traffic, the stationary queue length becomes larger stochastically when the bandwidth (i.e. the service rate) of the system decreases. For a given GPS server, we consider the similar problem to this. We define the monotonicity for the head of the line processor sharing(HLPS) servers in which the units in the heads of the queues are served simultaneously and the bandwidth allocated to each queue are determined by the numbers of units in the queues. GPS is a type of monotonic HLPS. We obtain the HLPS server whose queue length of a class stochastically bounds upper that of corresponding class in the given monotonic HLPS server for all classes. The queue lengths process of all classes in the obtained HLPS server has the stationary distribution of product form. When the given monotonic HLPS server is GPS server, we obtain the explicit form of the stationary queue lengths distribution of the bounding HLPS server. Numerical result shows how tight the stochastic bound is.