• Title/Summary/Keyword: Priority Consideration

Search Result 251, Processing Time 0.029 seconds

Heuristics for Job Shop Scheduling Problems with Progressive Weighted Tardiness Penalties and Inter-machine Overlapping Sequence-dependent Setup Times

  • Mongkalig, Chatpon;Tabucanon, Mario T.;Hop, Nguyen Van
    • Industrial Engineering and Management Systems
    • /
    • v.4 no.1
    • /
    • pp.1-22
    • /
    • 2005
  • This paper presents new scheduling heuristics, namely Mean Progressive Weighted Tardiness Estimator (MPWT) Heuristic Method and modified priority rules with sequence-dependent setup times consideration. These are designed to solve job shop scheduling problems with new performance measures - progressive weighted tardiness penalties. More realistic constraints, which are inter-machine overlapping sequence-dependent setup times, are considered. In real production environments, inter-machine overlapping sequence-dependent setups are significant. Therefore, modified scheduling generation algorithms of active and nondelay schedules for job shop problems with inter-machine overlapping sequence-dependent setup times are proposed in this paper. In addition, new customer-based measures of performance, which are total earliness and progressive weighted tardiness, and total progressive weighted tardiness, are proposed. The objective of the first experiment is to compare the proposed priority rules with the consideration of sequence-dependent setup times and the standard priority rules without setup times consideration. The results indicate that the proposed priority rules with setup times consideration are superior to the standard priority rules without the consideration of setup times. From the second experiment and the third experiment to compare the proposed MPWT heuristic approach with the efficient priority rules with setup times consideration, the MPWT heuristic method is significantly superior to the Batched Apparent Tardiness Cost with Sequence-dependent Setups (BATCS) rule, and other priority rules based on total earliness and progressive weighted tardiness, and total earliness and tardiness.

On Optimal Replacement Policies for a Deteriorating System (기능저하 시스템에서의 최적 교체 정책)

  • Ji Hwan Chan
    • Journal of Korean Society for Quality Management
    • /
    • v.30 no.4
    • /
    • pp.94-105
    • /
    • 2002
  • In this paper, replacement problems for a deteriorating system are considered. In the system under consideration, the successive lifetimes after repair become shorter and shorter, while the consecutive repair times become longer and longer. More specifically, the lifetimes of the system form a nonhomogeneous Poisson process, whereas the consecutive repair times constitute a stochastically increasing geometric process. Optimal replacement policies for the long-run average cost rate and the steady state availability are considered. Also taking the cost and the availability into consideration at the same time, the properties of optimal policies under the Cost Priority Policy and the Availability Priority Policy are obtained.

Study on the Priority Decision for Redevelopment of Agricultural Reservoir (농업용저수지 재개발 우선순위 결정 연구)

  • Kim, Hae-Do;Kim, Sun-Joo;Lee, Kwang-Ya
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.51 no.6
    • /
    • pp.63-68
    • /
    • 2009
  • Most of agricultural reservoirs in Korea have no function of flood control except 5% of reservoirs even exposed to natural disaster. In addition, there are increasing needs for the reservoir to guarantee the release of environmental flow to the downstream. Thus, the purpose of this paper is to study the priority decision method for the reservoir redevelopment satisfying both water utilization and flood control. The major scopes of this research are to set up six priority indices and to make needed GIS data for calculating each priority. There is important consideration of obtaining the data or not in deciding the indices. Although the detailed indices is expected to better reflect redevelopment priority but the subjective indices like, 'opinion' and 'landscape' are excluded. From the results, it will enables the six priority indices to really assist in decision redevelopment priority of agricultural reservoirs.

A scheduling algorithm for conditonal resources sharing consideration (조건부 자원 공유를 고려한 스케쥴링 알고리즘)

  • 인지호;정정화
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.33A no.2
    • /
    • pp.196-204
    • /
    • 1996
  • This paper presents a new scheduling algorithm, which is the most improtant subtask in the high level synthesis. The proposed algorithm performs scheduling in consideration of resource sharing concept based on characteristics of conditionsla bransches in the intermediate data structure. CDFG (control data flow graph) generated by a VHDL analyzer. This algorithm constructs a conditon graph based on time frame of each operation using both the ASAP and the ALAP scheduling algorithm. The conditon priority is obtained from the condition graph constructed from each conditional brance. The determined condition priority implies the sequential order of transforming the CDFG with conditonal branches into the CDFG without conditional branches. To minimize resource cost, the CDFG with conditional branches are transformed into the CDFG without conditonal brancehs according to the condition priority. Considering the data dependency, the hardware constraints, and the data execution time constraints, each operation in the transformed CDFG is assigned ot control steps. Such assigning of unscheduled operations into contorl steps implies the performance of the scheduling in the consecutive movement of operations. The effectiveness of this algorithm is hsown by the experiment for the benchmark circuits.

  • PDF

A Study on the SMEs Priority System in National R&D programs: Definition and interpretation of Terms (국가연구개발사업 중소기업 우선제도에 관한 소고: 관련 규정의 용어 정의 및 해석)

  • Jung, Dong Duck
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.11 no.4
    • /
    • pp.205-213
    • /
    • 2016
  • This study clarified the definition and interpretation of terms relating to SMEs Priority System. First, 'Domestic' is defined that the address of office is in our country. Second, 'Technology utilization capacity' is defined that the de facto capacity to technology commercialization and utilization. for example. development or production or sales activity of the production using national r&d performance. Third, 'priority' in priority consideration is defined that when there are many companies trying sign technology utilization contract, technology providers shoud provide the opportunity of signing contract to SMEs primarily. 'priority consideration' is defined that technology providers shoud try to do enough to sign a contract with SMEs. This study has significance in that raising the application of the current SMEs Priority System.

  • PDF

A Design of Bandwidth Allocation Scheme with Priority Consideration for Upstream Channel of Ethernet PON (Ethernet PON에서 서비스 클래스별 우선 순위를 고려한 상향 채널 대역 할당 기법)

  • 이호숙;유태환;문지현;이형호
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.28 no.11A
    • /
    • pp.859-866
    • /
    • 2003
  • In this paper, we designed the bandwidth allocation scheme with priority consideration for upstream channel access of EthernetPON. The objective of our scheme is to control the multi services in more effective way according to their CoS(Class of Service) or QoS(Quality of Service). The designed scheme considers transmission priority in the both side of OLT and ONU. In the OLT's view, the Two-step scheduling algorithm is applied with which we can support multiple bandwidth allocation policies simultaneously, i.e. SBA for the time-sensitive, constant rate transmission services and DBA for the best-effort services. This Two-step scheduling algorithm reduces the scheduling complexity by separating the process of transmission start time decision from the process of grant generation. In the ONU's view, the proposed scheme controls 8 priority queues of the 802.1d recommended 8 service classes. Higher priority queue is serviced in prior during the allowed GATE time from OLT. The OPNET modeling and simulation result compares the performance of each bandwidth allocation policy with SBA or DBA only approach.

Critical Criteria Based on Facility Condition Index for Supporting Priority Decision-making in Educational Facilities

  • Shin, Seung Woo;Yi, June Seong
    • International conference on construction engineering and project management
    • /
    • 2015.10a
    • /
    • pp.687-688
    • /
    • 2015
  • The objective of identifying the cause of inconsistency in determining priority of educational facility maintenance, any related factors were thoroughly identified and tested, to see if it has any effect on decision-making process in resource allocation for educational facilities. On the assumption that 'the more there are to be repaired/maintained and deferred, the higher the relevant cost will be, this will lead to a significant social loss. Accordingly, this study established a framework of determining resource allocation priority based on deferred maintenance and its related expenses. For doing so, it was required to determine relative ranking in terms of resource allocation within a pre-assigned school district, in consideration of the criticality of each deferred maintenance attribute/variable.

  • PDF

Priority Service Algorithm of Packet Switch for Improvement in QoS

  • Jung, Hae-Young;Lee, Heung-Jae;Choe, Jin-Kyu;Lee, Kyou-Ho
    • Journal of IKEEE
    • /
    • v.7 no.2 s.13
    • /
    • pp.181-187
    • /
    • 2003
  • In high speed packet switching network, packet service by priority scheme prefer to QoS. Efficient packet service according to the priority scheme in high speed packet switch is a key point. Therefore development of priority service algorithm in the packet switch is very important. In this paper, we proposed W-iSLIP algorithm that service time take queue length into consideration and compared the proposed W-iSLIP algorithm to other previous proposed algorithm through simulation. Simulation results show 2.6% performance elevation in average delay, and 34.6% performance elevation in priority service.

  • PDF

AN M/G/1 QUEUEING SYSTEM WITH MULTIPLE PRIORITY CLASSES

  • Han, Dong-Hwan
    • Journal of applied mathematics & informatics
    • /
    • v.1 no.1
    • /
    • pp.55-74
    • /
    • 1994
  • We consider an M/G/1 queueing system with multiple priority classes of jobs. Considered preemptive rules are the preemptive-resume preemptive-repeat-identical, and preemptive-repeat-different policies. These three preemptive rules will be analyzed in parallel. The key idea of analysis is based on the consideration of a busy period as composite of delay cycle. As results we present the exact Laplace-Stieltjecs(L.S) transforms of residence time and completion time in the system.

An Outline of Food Ethics (음식윤리 개요)

  • Kim, Suk-Shin
    • Food Science and Industry
    • /
    • v.49 no.2
    • /
    • pp.83-97
    • /
    • 2016
  • This review was performed to outline the food ethics to the professionals in the field of food science and industries. Food ethics is the ethics or ethical consideration concerning food; while, the keywords of food ethics are a life, happiness and the wisdom. The ultimate goal as well as the first principle of food ethics is a sustainable living of human race. In order to reach the goal a coexistence of humans and nature, coexistence of humans and humans, and the fulfillment of essential requirements of a food are needed. The needs yield six categorical imperatives such as a respect for life, preservation of nature, distributive justice without deception or fakes, prior consideration of consumer, moderation and balance neither overs nor shorts, and the assurance of safety. The core principles corresponding to the categorical imperatives include a respect for life, environmental preservation, justice, priority of consumer, dynamic equilibrium, and the priority of safety. The core principles approach is a simple, clear, and practical method in solving ethical issues. The code of food ethics is also based on the core principles.