• Title/Summary/Keyword: Priority Structure

Search Result 396, Processing Time 0.025 seconds

A Double-Ended Priority Queue with O(1) Insertion Amortized Time (상수 삽입 전이 시간을 가지는 양단 우선순위 큐)

  • Jung, Hae-Jae
    • The KIPS Transactions:PartA
    • /
    • v.16A no.3
    • /
    • pp.217-222
    • /
    • 2009
  • Priority queues can be used in applications such as scheduling, sorting, retrival based on a priority like gene searching, shortest paths computation. This paper proposes a data structure using array representation for double-ended priority queue in which insertion and deletion takes O(1) amortized time and O(logn) time, respectively. To the author's knowledge, all the published array-based data structures for double ended priority queue support O(logn) time insertion and deletion operations.

Design of Structural Models for Constructing a Goal Alternatives Disposition System in Large-Scale R&D Projectsr (대규모 R&D 프로젝트에 있어서 목표대체안 처리시스템의 구축을 위한 구조모형의 설계)

  • Kwon, Cheol-Shin;Cho, Keun-Tae
    • IE interfaces
    • /
    • v.15 no.4
    • /
    • pp.460-473
    • /
    • 2002
  • The objective of this paper is to design a Goal Alternatives Disposition System having three main subsystems for setting, evaluating and selecting goal alternatives. For setting of goal alternatives, System Alternatives Tree(SAT) structure will be developed, which has a computation algorithm for setting decision alternatives by the concept of System Priority Number(SPN). For evaluating and selecting of goal alternatives; First, Normative and Exploratory Priority Indices which consider technical performance to the goal, cost and feasibility are developed respectively. Second, Integrated Priority Index is built up to determine the total priority of the Goal Alternatives Disposition(GAD) system. For the design and verification of the GAD system, technological forecasting structure theory, systems engineering methodology will be used.

Multi-Item Inventory Problems Revisited Using Genetic Algorithm

  • Das, Prasun
    • Management Science and Financial Engineering
    • /
    • v.13 no.2
    • /
    • pp.29-46
    • /
    • 2007
  • This paper makes an attempt to compare the two important methods for finding solutions of multi-item inventory problem with more than one conflicting objectives. Panda et al.[9] discusses a distance-based method to find the best possible compromise solution with variation of priority under the given weight structure. In this paper, the problem in [9] is revisited through the Pareto-optimal front of genetic algorithm with the help of a situation of retail stocking of FMCG business. The advantages of using the solutions from the perspective of the decision maker obtained through multi-objective optimization are highlighted in terms of population search, weighted goals and priority structure, cost, set of compromise solutions along with prevention of stock-out situation.

MANAGEMENT DECISION-MAKING FOR SUGARCANE FERTILIZER MIX PROBLEMS THROUGH GOAL PROGRAMMING

  • Sharma, Dinesh K.;Ghosh, Debasis;Alade, Julius A.
    • Journal of applied mathematics & informatics
    • /
    • v.13 no.1_2
    • /
    • pp.323-334
    • /
    • 2003
  • This paper presents a goal-programming (GP) model for management decision-making for sugarcane fertilizer mix problems. Sensitivity analysis on the priority structure of the goals has been performed to obtain all possible solutions. The study uses Euclidean distance function to measure distances of all possible solutions from the ideal solution. The optimum solution is determined from the minimum distance between the ideal solution and other possible solutions of the problem. The optimum solution corresponds to the appropriate priority structure of the problem in the decision-making context. furthermore, the results obtained from sensitivity analysis on the cost of combination of fertilizers confirm the priority structure.

A Model for Reducing Priority Inversion in Real Time Server System (실시간 서버 시스템에서 우선 순위 반전현상을 감소하기 위한 모델)

  • Choe, Dae-Su;Im, Jong-Gyu;Gu, Yong-Wan
    • The Transactions of the Korea Information Processing Society
    • /
    • v.6 no.11
    • /
    • pp.3131-3139
    • /
    • 1999
  • Satisfying the rigid timing requirements of various real-time activities in real-time systems often requires some special methods to tune the systems run-time behaviors. Unbounded blocking can be caused when a high priority activity cannot preempt a low priority activity. In such situation, it is said that a priority inversion has occurred. The priority inversion is one of the problems which may prevent threads from meeting the deadlines in the real-time systems. It is difficult to remove such priority inversion problems in the kernel at the same time to bound the worst case blocking time for the threads. A thread is a piece of executable code which has access to data and stack. In this paper, a new real-time systems. It is difficult to remove such priority inversion problems in the kernel at the same time to bound the worst case blocking time for the threads. A threads is a piece of executable code which has access to data and stack. In this paper, a new real-time server model, which minimizes the duration of priority inversion, is proposed to reduce the priority inversion problem. The proposed server model provides a framework for building a better server structure, which can not only minimize the duration of the priority inversion, but also reduce the deadline miss ratio of higher priority threads.

  • PDF

Study on Dynamic Priority Collision Resolution Algorithm in HFC-CATV Network (HFC-CATV 망에서 동적 우선순위 충돌해결알고리즘에 관한 연구)

  • Lee, Su-Youn;Chung, Jin-Wook
    • The KIPS Transactions:PartC
    • /
    • v.10C no.5
    • /
    • pp.611-616
    • /
    • 2003
  • Recently, the HFC-CATV network stand in a substructure of superhighway information network. Because of sharing up to 500 of subscribes, the Collision Resolution Algorithm needs in the upstream channel of HFC-CATV network. In order to provide Quality of Service (QoS) to users with real-time data such as voice, video and interactive service, the research of Collision Resolution Algorithm must include an effective priority scheme. In IEEE 802.14, the Collision Resolution Algorithm has high request delay because of static PNA(Priority New Access) slots structure and different priority traffics with the same probability. In order to resolve this problem, this paper proposed dynamic priority collision resolution algorithm with ternary tree algorithm. It has low request delay according to an increase of traffic load because high priority traffic first resolve and new traffic content with different probability. In the result of the simulation, it demonstrated that the proposed algorithm needs lower request delay than that of ternary tree algorithm with static PNA slots structure.

Prioritization of Potential Technology for Establishing a Safe Work Zone Environment (안전한 도로 공사구간 환경 구축에 필요한 기술의 우선순위 선정)

  • Kim, Jin Guk;Yang, Choong Heon;Yun, Duk Geun
    • International Journal of Highway Engineering
    • /
    • v.17 no.6
    • /
    • pp.117-126
    • /
    • 2015
  • PURPOSES : This study prioritizes potential technology for establishing a safe work zone environment on roadways. We consider almost all conceivable technologies that enable mitigation of unexpected accidents for both road workers and drivers. METHODS : This study suggests a methodology to set the priority of potential technology for establishing a safe work zone environment by using the analytical hierarchy process (AHP). For this purpose, the AHP structure was first developed. Thereafter, a web-based survey was conducted to collect experts' opinions. Based on the survey results, weights associated with the relevant criteria of the developed structure were estimated. With the consistency index (CI) and consistency ratio (CR), we verified the estimated weights. In addition, a sensitivity analysis was performed to confirm whether the estimated weights were reliable. We finally proposed the priority for potential technology for establishing a safe work zone environment on roadways. RESULTS : In the first level, safety technology has the highest priority, and real-time information delivery for work zone, hazard warning for drivers, and temporal automated operation for traffic facilities were selected in the second level of hierarchy. CONCLUSIONS : The results imply that establishing the priority will be useful to establish a future road map for improving the work environment for road workers and drivers by employing appropriate protection facilities and developing safety systems.

M/G/1 Preemptive Priority Queues With Finite and Infinite Buffers (유한 및 무한 용량 대기열을 가지는 선점 우선순위 M/G/1 대기행렬)

  • Kim, Kilhwan
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.43 no.4
    • /
    • pp.1-14
    • /
    • 2020
  • Recently, M/G/1 priority queues with a finite buffer for high-priority customers and an infinite buffer for low-priority customers have applied to the analysis of communication systems with two heterogeneous traffics : delay-sensitive traffic and loss-sensitive traffic. However, these studies are limited to M/G/1 priority queues with finite and infinite buffers under a work-conserving priority discipline such as the nonpreemptive or preemptive resume priority discipline. In many situations, if a service is preempted, then the preempted service should be completely repeated when the server is available for it. This study extends the previous studies to M/G/1 priority queues with finite and infinite buffers under the preemptive repeat-different and preemptive repeat-identical priority disciplines. We derive the loss probability of high-priority customers and the waiting time distributions of high- and low-priority customers. In order to do this, we utilize the delay cycle analysis of finite-buffer M/G/1/K queues, which has been recently developed for the analysis of M/G/1 priority queues with finite and infinite buffers, and combine it with the analysis of the service time structure of a low-priority customer for the preemptive-repeat and preemptive-identical priority disciplines. We also present numerical examples to explore the impact of the size of the finite buffer and the arrival rates and service distributions of both classes on the system performance for various preemptive priority disciplines.

Evacuation Safety Evaluation of Tourist Hotels with the Fire Alarm Method

  • Moon, Sung-Chun;Kong, Ha-Sung
    • International Journal of Advanced Culture Technology
    • /
    • v.9 no.4
    • /
    • pp.363-375
    • /
    • 2021
  • The purpose of this study is to analyze the safety of evacuation using the Pathfinder program for the alert at once, the priority alarm method, the priority alarm method for the four floors above, and the sequential priority alarm method, which is a modification of the priority alarm method specified in the tourist hotel building. Currently, in Korea's National Fire Safety Codes (NFSC), fire alarm methods are compulsorily applied differently depending on the number of floors and total floor area of a building. Although the growth rate is getting faster due to the diversification of building structures, it is still an obstacle to improving evacuation safety to comply with the standardized fire alarm method in NFSC. As a result of the experiment, the evacuation time was found to be faster with the priority alarm method for the four floors above than the priority alarm method applied to the specific firefighting object. Compared to the priority alarm method applied to the tourist hotel, which is a specific firefighting target with 5 or more floors and a total floor area of more than 3,000m2, the time was shortened by 3.7 seconds when measured by applying the priority alarm method for the four floors directly above. This indicates that it is necessary to take measures to select a fire alarm method suitable for the structure and environmental conditions of the building rather than applying the uniform NFSC regulations.

The Structure and The Implementation of Fully Interconnected ATM Switch (Part I : About The Structure and The Performance Evaluation) (완전 결합형 ATM 스위치 구조 및 구현 (I부 : 구조 설정 및 성능 분석에 대하여))

  • 김근배;김경수;김협종
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.1
    • /
    • pp.119-130
    • /
    • 1996
  • This paper is the part I of the full study about improved structure of fully interconnected ATM switch to develop the small sized switch element and practical implemention of switch network. This part I paper describes about proposed switch structure, performance evaluations and some of considerations to practical implementation. The proposed structure is constructed of two step buffering scheme in a filtered multiplexer. First step buffering is carried out by small sized dedicated buffers located at each input port. And second step buffering is provided by a large sized common buffer at the output port. To control bursty traffic, we use speed up factor in multiplexing and priority polling according to the levels of buffer occupancy. Proposed structure was evaluated by computer simulation with two evaluation points. One is comparision of multiplexing discipline between hub polling and priority polling. The ogher is overall which should be considered to improve the practical implementation.

  • PDF