• 제목/요약/키워드: Preemptive

검색결과 414건 처리시간 0.032초

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

  • 박문주
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제15권2호
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    • pp.89-97
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    • 2009
  • 유비쿼터스 환경에서 널리 사용되고 있는 내장형 시스템에서는 메모리 사용량의 감소와 신뢰성 등의 이유로 쓰레드 기반 프로그래밍 모델보다는 이벤트-구동형 프로그래밍 모델을 채용하는 경우가 많다. 그러나 내장형 시스템의 소프트웨어가 점점 더 복잡해지면서, 내장형 시스템을 위한 소프트웨어를 이벤트-구동형 프로그래밍 모델의 단일 이벤트 핸들러로 프로그램 하는 것은 매우 어려운 과제가 되고 있다. 본 논문에서는 내장형 시스템의 설계에 비선점형 스케줄링 기법을 도입하기 위하여, 다항시간의 스케줄 가능성 평가를 위한 충분조건과 이를 이용한 효율적인 스케줄 가능성 검사 방법을 제시하며, 또한 내장형 시스템에서의 서브-태스크의 활용이 비선점형 스케줄링을 채용했을 때의 단점인 낮은 처리기 이용률을 극복할 수 있는 방안임을 보인다.

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

  • 방은치;김수연;이현숙;강용인;김명희;조경숙
    • The Korean Journal of Pain
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    • 제13권1호
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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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통증의 기억과 선행진통 (Memory of Pain and Preemptive Analgesia)

  • 송선옥
    • Journal of Yeungnam Medical Science
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    • 제17권1호
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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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네트워크 기반의 Preemptive 동작을 통한 끊김없는 서비스 제공 메커니즘 (A Mechanism for Seamless Mobility Service with the Network-based Preemptive Operations)

  • 민병웅;정희창;김동일
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2007년도 추계종합학술대회
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    • pp.54-57
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    • 2007
  • 끊임없는 서비스를 제공하기 위해 많은 연구가 진행되고 있다. 이러한 연구는 단말의 핸드오버에 따른 지연 시간을 최소화하는데 초점을 두고 있다. 본 논문에서는 네트워크 기반의 Preemptive 동작을 통해 끊김없는 서비스를 제공하고자 한다. 네트워크 기반의 우선 동작은 L2 트리거 정보를 이용하여 단말의 핸드오버가 판단되면, 전송중인 데이터를 핸드오버 전에 소속된 네트워크에서 버퍼링을 통해 데이터의 손실을 줄인다. 핸드오버 전의 소속된 네트워크에서 버퍼링은 단말의 핑퐁현상에 대한 대안을 제공할 수 있다. 단말의 이동 후, 이동 여부를 확인한 후 버퍼링된 데이터를 보냄으로써 끊김없는 서비스를 제공한다. 핸드오버 시그널링의 빠른 처리를 위해 코어 망에서는 MPLS-LSP(MultiProtocol Label Switching-Label Switched Path)를 이용한다.

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

  • 송원섭;김여근
    • 한국경영과학회지
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    • 제34권2호
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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.

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

  • 배홍열;송태광;전윤배;오창영;김윤재;이경수;박치용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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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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    • 제5권3호
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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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    • 제23권7호
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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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    • 제24권3호
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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.

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

  • 이준학;김인령;윤채식;정은배;이기남;문준일
    • The Korean Journal of Pain
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    • 제10권2호
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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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