• Title/Summary/Keyword: Admission control mechanism

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A Dynamic Sweep Scheme Enabling Scheduling Period Expansions for Continuous Media Playback (연속매체 재연에 적합한 스케줄링 주기 확장을 허용하는 동적 Sweep 기법)

  • Lim, Sung-Chae
    • The KIPS Transactions:PartA
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    • v.12A no.5 s.95
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    • pp.355-364
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    • 2005
  • With fast advances in computing power and network technologies, online streaming services of continuous media (CM) have been popularly implemented on the Web. To implement such services, a variety of CM streams need to be processed efficiently, so that the Sweep scheme was proposed. This scheme has several advantages such as hiccup-free playbacks and seek-time optimization. In this scheme, however, the entire CM streams are scheduled with a single scheduling period, called a cycle. Since only one scheduling period is allowed in this scheme, a significant amount of disk time is usually wasted because of its inflexible disk schedules. To solve this, we propose a new dynamic Sweep scheme. For this, we devise an algorithm that is able to expand scheduling periods of serviced CM streams and propose a new admission control mechanism guaranteeing hiccup-free playbacks. To show performance gains, we execute various simulation experiments. From the experimental results, we can see that the proposed scheme outperforms the Sweep scheme in terms of disk utilization and scheduling flexibility.

Pre-Hospital and In-Hospital Management of an Abdominal Impalement Injury Caused by a Tree Branch

  • Ahn, So Ra;Lee, Joo Hyun;Kim, Keun Young;Park, Chan Yong
    • Journal of Trauma and Injury
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    • v.34 no.4
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    • pp.288-293
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    • 2021
  • In South Korea, most patients who visit trauma centers with abdominal injuries have blunt trauma, and penetrating injuries are relatively rare. In extremely rare cases, some patients are admitted with a long object penetrating their abdomen, and these injuries are referred to as abdominal impalement injuries. Most cases of impalement injuries lead to fatal bleeding, and patients often die at the scene of the accident. However, patients who survive until reaching the hospital can have a good prognosis with optimal treatment. A 68-year-old female patient was admitted to the trauma center with a 4-cm-thick tree branch impaling her abdomen. The patient was transported by a medical helicopter and had stable vital signs at admission. The branch sticking out of the abdomen was quite long; thus, we carefully cut the branch with an electric saw to perform computed tomography (CT). CT revealed no signs of major blood vessel injury, but intestinal perforation was observed. During laparotomy, the tree branch was removed after confirming that there were no vascular injuries, and enterostomy was performed because of extensive intestinal injury. After treating other injuries, the patient was discharged without any complications except colostomy. Abdominal impalement injuries are treated using various approaches depending on the injury mechanism and injured region. However, the most important consideration is that the impaled object should not be removed during transportation and resuscitation. Instead, it should only be removed after checking for injuries to blood vessels during laparotomy in an environment where injury control is possible.

A Study of an Association Admission Method for Public Wireless LAN Systems (고속 공중 무선랜 시스템을 위한 효율적인 연결 수락 제어방법의 연구)

  • Lee, Hyun-Woo;Yoon, Hong;Yoon, Chong-Ho
    • Journal of Advanced Navigation Technology
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    • v.7 no.2
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    • pp.149-155
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    • 2003
  • This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP. According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

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Longitudinal flowcytometric measurement of respiratory burst activity of neutrophils in patients with pneumonia (폐렴경과 중 순환 호중구의 Respiratory Burst 활성도 변화)

  • Lee, Jae Myung;Lee, Jong Min;Kim, Dong Gyu;Choi, Jeong Eun;Mo, Eun Kyung;Park, Myung Jae;Lee, Myung Goo;Hyun, In Gyu;Jung, Ki-Suck;Park, Chan Jeoung
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.5
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    • pp.728-735
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    • 1996
  • Background : Recognition and ingestion of opsonized microorganisms by neutrophils induces the burst of oxidative metabolic activity. Products of the respiratory burst activity provide powerful oxygen dependent killing mechanism. Measurement of respiratory burst activity has been a major indicator of the functional capacity of neutrophils. We determined the respiratory burst activity of neutrophils in patients with pneumonia and observed the changes during the clinical course of pneumonia. Methods: The EDTA blood was drawn from 24 normal controls and same numbers of pneumonia patients. The respiratory burst activity(with the production of $H_2O_2$ which changes nonfluorescent DCF-DA to green fluorescent DCF) in the non-stimulated state and the stimulated state with fMLP and PMA of neutrophils was measured by flowcytometry at day 1, 3, 5, 7 and 9 of admission. Results: The respiratory burst activity of neutrophils was mildly increased by stimulation with fMLP. But there was no statistical significance between normal control and patients with pneumonia. The respiratory burst activity of neutrophils was markedly increased by stimulation with PMA in both groups. There was a significant difference in response to PMA between normal control and patients with pneumonia. The production of hydrogen peroxide from neutrophils was decreased during early course of pneumonia and it was recuperated gradually to normal level in 9 days. Conclusion : Hydrogen peroxide production from neutrophils was suppressed during early course of pneumonia and restored after treatment. It is suggested that the production of oxygen radical in response to PMA stimulation from each neutrophils is decreased rather than increased during the early course of pneumonia.

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