• Title/Summary/Keyword: Preemptive

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Non-Preemptive Fixed Priority Scheduling for Design of Real-Time Embedded Systems (실시간 내장형 시스템의 설계를 위할 비선점형 고정우선순위 스케줄링)

  • Park, Moon-Ju
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.2
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    • pp.89-97
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    • 2009
  • Embedded systems widely used in ubiquitous environments usually employ an event-driven programming model instead of thread-based programming model in order to create a more robust system that uses less memory. However, as the software for embedded systems becomes more complex, it becomes hard to program as a single event handler using the event-driven programming model. This paper discusses the implementation of non-preemptive real-time scheduling theory for the design of embedded systems. To this end, we present an efficient schedulability test method for a given non-preemptive task set using a sufficient condition. This paper also shows that the notion of sub-tasks in embedded systems can overcome the problem of low utilization that is a main drawback of non-preemptive scheduling.

The Preemptive Analgesia with Intravenous Nalbuphine-Ketorolac in Gynecologic Surgery (부인과 수술에서 정맥내 Nalbuphine-Ketorolac을 이용한 선행진통 효과의 평가)

  • Bang, Eun-Chi;Kim, Su-Yeon;Lee, Hyun-Sook;Kang, Yong-In;Kim, Myoung-Hee;Cho, Kyoung-Sook
    • The Korean Journal of Pain
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    • v.13 no.1
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    • pp.38-43
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    • 2000
  • Background: Preemptive analgesia may decrease postoperative pain by preventing nociceptive inputs generated during surgery. The preemptive effect of intravenous nalbuphine was examined in gynecological surgery. Methods: Forty female patients scheduled for gynecological surgery were randomly allocated into two groups. Each patient received 10 mg of intravenous nalbuphine as a bolus dose at the closure of peritoneum in group I (n=20) and before the skin incision in group II (n=20). After the bolus dose, the intravenous patient controlled analgesia (IV-PCA) which contained 50 mg of nalbuphine, 120 mg of ketorolac, 0.25 mg of droperidol and 90 ml of 5% dextrose water was given continuously at the rate of 2 ml/min. The postoperative visual analogue scale pain score (VAS), the total amount of the analgesics used, the degree of satisfaction of the patients and the developement of side effects were examined for 2 days. Results: VAS were significantly lower in group II than in group I after 9 and 12 hours. The cumulative consumption of analgesics in group II was significantly less than in group I. Most patients were satisfied with this regimen. There were no remarkable side effects. Conclusions: Preemptive analgesia with intravenous nalbuphine decreased postoperative pain and analgesic requirement. The analgesic effect of IV-PCA with nalbuphine-ketorolac was effective in control of postoperative pain in gynecologic surgery.

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Memory of Pain and Preemptive Analgesia (통증의 기억과 선행진통)

  • Song, Sun-Ok
    • Journal of Yeungnam Medical Science
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    • v.17 no.1
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    • pp.12-20
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    • 2000
  • The memory of pain can be more damaging than its initial experience. Several factors arc related the directions of pain memory: current pain intensity, emotion, expectation of pain, and peak intensity of previous pain. The possible mechanisms behind the memory of pain are neuroplastic changes of nervous system via peripheral and central sensitization. Peripheral sensitization is induced by neurohumoral alterations at the site of injury and nearby. Biochemicals such as K+, prostaglandins, bradykinin, substance P, histamine and serotonin, increase transduction and produce continuous nociceptive input. Central sensitization takes place within the dorsal horn of spinal cord and amplifies the nociceptive input from the periphery. The mechanisms of central sensitization involve a variety of transmitters and postsynaptic mechanisms resulting from the activations of NMDA receptors by glutamate. and activation of NK-1 tachykinnin receptors by substance-P and neurokinnin. The clinical result of peripheral and central sensitization is hyperalgesia, allodynia, spontaneous pain, referred pain, or sympathetically maintained pain. These persistent sensory responses to noxious stimuli arc a form of memory. The hypothesis of preemptive analgesia is that analgesia administered before the painful stimulus will prevent or reduce subsequent pain and analgesic requirements in comparison to the identical analgesic intervention administered after the painful stimulus, by preventing or reducing the memory of pain in the nervous system. Conventionally, pain management was initiated following noxious stimuli such as surgery. More recently, however many have endorsed preemptive analgesia initiated before surgery. Treatments to control postsurgical pain are often best started before injury activates peripheral nociceptors and triggers central sensitization. Such preemption is not achieved solely by regional anesthesia and drug therapy but also requires behavioral interventions to decrease anxiety or stress. Although the benefit of preemptive analgesia may not be obvious in every circumstance, and in many cases may not sufficient to abolish central sensitization, it is an appropriate and human goal of clinical practice.

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A Mechanism for Seamless Mobility Service with the Network-based Preemptive Operations (네트워크 기반의 Preemptive 동작을 통한 끊김없는 서비스 제공 메커니즘)

  • Min, Byung-Ung;Chung, Hee-Chang;Kim, Dong-Il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.54-57
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    • 2007
  • Much researches have studied for seamless mobility service. Those focused on minimizing the delay time due to the handover. In this paper, we suggest seamless mobility service with the network-based preemptive operations. With these operations, if it's found that the MT(Mobile Terminal)'s handover using L2-trigger event, old access network buffers the delivering data. Therefore this can decrease the data drop rates. And also, this can deal with the ping-pong's phenomenon of MT. At the end of MT's movement, these operations can provide seamless mobility service sending buffered data after checking the MT's movement. This mechanism uses MPLS-LSP(MultiProtocol Label Switching-Label Switched Path) in core network for fast process.

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Two-Sided Assembly Line Balancing with Preemptive Multiple Goals Using an Evolutionary Algorithm (진화알고리즘을 이용한 선취적 다목표 양면조립라인 밸런싱)

  • Song, Won-Seop;Kim, Yeo-Keun
    • Journal of the Korean Operations Research and Management Science Society
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    • v.34 no.2
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    • pp.101-111
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    • 2009
  • This paper considers two-sided assembly line balancing with preemptive multiple goals. In the problem, three goals are taken into account in the following priority order : minimizing the number of mated-stations, achieving the goal level of workload smoothness, and maximizing the work relatedness. An evolutionary algorithm is used to solve the multiple goal problems. A new structure is presented in the algorithm, which is helpful to searching the solution satisfying the goals in the order of the priority. The proper evolutionary components such as encoding and decoding method, evaluation scheme, and genetic operators, which are specific to the problem being solved, are designed in order to improve the algorithm's performance. The computational results show that the proposed algorithm is premising in the solution quality.

Effect of preemptive weld overlay sequence on residual stress distribution for dissimilar metal weld of Kori nuclear power plant pressurizer (고리 원전 가압기 PWOL의 용접 방향이 이종금속용접부 잔류응력 분포에 미치는 영향)

  • Bae, H.Y.;Song, T.K.;Chun, Y.B.;Oh, C.Y.;Kim, Y.J.;Lee, K.S.;Park, C.Y.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.88-93
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    • 2008
  • Weld overlay is one of the residual stress mitigation method which arrest crack. An overlay weld sued in this manner is termed a preemptive weld overlay(PWOL). PWOL was good for distribution of residual stress of dissimilar metal weld(DMW) by previous research. Because range of overlay welding is wide relatively, residual stress distribution on PWR is affected by welding sequence. In order to examine the effect of welding sequence, PWOL was applied to a specific DMW of KORI nuclear power plant by finite element analysis method. As a result, the welding direction that from nozzle to pipe is better good for residual stress distribution on PWR.

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Study on Preemptive Real-Time Scheduling Strategy for Wireless Sensor Networks

  • Zhi-bin, Zhao;Fuxiang, Gao
    • Journal of Information Processing Systems
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    • v.5 no.3
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    • pp.135-144
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    • 2009
  • Most of the tasks in wireless sensor networks (WSN) are requested to run in a real-time way. Neither EDF nor FIFO can ensure real-time scheduling in WSN. A real-time scheduling strategy (RTS) is proposed in this paper. All tasks are divided into two layers and endued diverse priorities. RTS utilizes a preemptive way to ensure hard real-time scheduling. The experimental results indicate that RTS has a good performance both in communication throughput and over-load.

The Performance Analysis of CPU scheduling Algorithms in Operating Systems

  • Thangakumar Jeyaprakash;Ranjana P;Sambath M
    • International Journal of Computer Science & Network Security
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    • v.23 no.7
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    • pp.165-170
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    • 2023
  • Scheduling algorithms plays a significant role in optimizing the CPU in operating system. Each scheduling algorithms schedules the processes in the ready queue with its own algorithm design and its properties. In this paper, the performance analysis of First come First serve scheduling, Non preemptive scheduling, Preemptive scheduling, Shortest Job scheduling and Round Robin algorithm has been discussed with an example and the results has been analyzed with the performance parameters such as minimum waiting time, minimum turnaround time and Response time.

Preemptive Use of Ketamine on Post Operative Pain of Appendectomy

  • Behdad, Akbar;Hosseinpour, Mehrdad;Khorasani, Parastoo
    • The Korean Journal of Pain
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    • v.24 no.3
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    • pp.137-140
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    • 2011
  • Background: Although early reviews of clinical findings were mostly negative, there is still a widespread belief for the efficacy of preemptive analgesia among clinicians. In this study, we evaluated whether the preemptive use of ketamine decreases post operative pain in patients undergoing appendectomy. Methods: In double-blind, randomized clinical trials, 80 adult male patients undergoing an operation for acute appendicitis were studied. Patients were randomly assigned to two groups. In the operating room, patients in the ketamine group received 0.5 mg/kg of ketamine IV 10 minutes before the surgical incision. In the control group, 0.5 mg/kg of normal saline was injected. The pain intensity was assessed at time 0 (immediately after arousal) and 4, 12, and 24 hours postoperatively using the 10 points visual analogue scale (VAS). Results: Eighty patients (40 for both groups) were enrolled in this study. For all of the evaluated times, the VAS score was significantly lower in the ketamine group compared to the control. The interval time for the first analgesic request was $23.1{\pm}6.7$ minutes for the case group and $18.1{\pm}7.3$ minutes for the control (P = 0.02). The total number of pethidine injections in the first 24 hours postoperatively was $0.6{\pm}0.6$ for the case group and $2.0{\pm}0.8$ for the controls (P = 0.032). There were no drug side effects for the case group. Conclusions: A low dose of intravenously administered ketamine had a preemptive effect in reducing pain after appendectomy.

Effects of Preemptive Analgesia by Epidural Bupivacaine and Fentanyl on Postoperative Pain Control in Lower Abdominal Surgery (하복부 수술에서 경막외 Bupivacaine과 Fentanyl에 의한 선행진통법이 술후 통증관리에 미치는 효과)

  • Lee, Jun-Hak;Kim, In-Ryeong;Yoon, Chae-Sik;Chung, Eun-Bae;Lee, Ki-Nam;Moon, Jun-Il
    • The Korean Journal of Pain
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    • v.10 no.2
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    • pp.185-190
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    • 1997
  • Background: Preemptive analgesia is an antinociceptive treatment that prevents the establishment of altered central processing which amplifies postoperative pain. A controversy exists over the effectiveness and clinical value of preemptive analgesia. We studied whether epidural bupivacaine and fentanyl prior to surgery could possibly affect postoperative pain and analgesic demands, as compared to administration of same at end of surgery. Methods: Forty patients scheduled for lower abdominal surgery were randomly assigned to one of two groups and prospectively studied in a double-blind method. Group 1(n=20) received epidural injection of 15 ml bupivacaine 0.25% with fentanyl 100 y g before surgery while group 2(n=20) received the same injection at the end of their surgery respectively. Postoperative analgesia consisted of basal plus patient-controlled mode of epidural bupivacaine and fentanyl from PCA system. Postoperative visual analog pain scores(VAPS), analgesics consumption, supplementary analgesics requirement and side effects were assessed for 3 postoperative days. Results: There were no significant difference in analgesics requirement and pain scores, at any time, during rest or after movement, in measurement between the groups. Conclusions: We conclude no clinical value of effectiveness in administering epidural bupivacaine-fentanyl before surgery as compared to administration after surgery.

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