• Title/Summary/Keyword: starvation phenomenon

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Bus Arbitration Policy Using Random Function Manager (랜덤함수 매니저를 이용한 버스중재 방식)

  • Lee, Kook-Pyo;Yoon, Yung-Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.11
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    • pp.34-39
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    • 2009
  • In this study, we have proposed the random function arbitration method using a random function manager in other to use the merits and overcome the demerits of fixed priority and round-robin, Starvation phenomenon can be generated from the master having low priority in fixed priority method. Also, round-robin method can't give a priority to important master, however, as the proposed random function arbitration method can be random set the rate of fixed priority and round-robin, we can solve the problems of conventional arbitration methods. From TLM simulation, we confirmed that the bus utilization of master could be controled from 32% to 16% and the starvation phenomenon of master could be prevented.

A pheromone mutant of Schizosaccharomyces pombe displays nucleolar fragmentation

  • Jun, Jai-Hyun;Kim, Dae-Myung
    • BMB Reports
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    • v.41 no.3
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    • pp.248-253
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    • 2008
  • Stresses and nutritional starvation are two main external signals for the induction of sex pheromones in the fission yeast Schizosaccharomyces pombe. In an attempt to identify the components involved in transduction of starvation signals, we screened 135 temperature-sensitive (ts) mutants and isolated 6 mutants that induced the pheromone even in the presence of a nitrogen source. These mutants exhibited two distict induction phenotypes: pheromone induction at restrictive but not at permissive temperatures; and pheromone induction at both permissive and restrictive temperatures. The times required for the maximum pheromone induction at the restrictive temperature differed slightly in each mutant. In addition to the pheromone induction phenotype, the ts243 and ts304 mutants exhibited cell-division-cycle defects. The ts304 mutant cells showed an abnormal cytoplasmic DAPI staining pattern. The nucleolus of this mutant seemed to be fragmented, a phenomenon which is typically observed in aged yeast cells. The result of our genetic analysis indicated that the pheromone induction mutants belonged to 6 separate complementation groups. We designated these mutants pws1 to pws6.

Design of Hybrid Arbitration Policy and Analysis of Its Bus Efficiency and Request Time (하이브리드 버스중재방식의 설계 및 버스효율정과 요청시간에 대한 분석)

  • Lee, Kook-Pyo;Yoon, Yung-Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.3
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    • pp.69-74
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    • 2009
  • We propose the novel Hybrid bus arbitration policy that prevents starvation phenomenon presented in fixed priority and effectively assigns a priority to each master by mixing fixed priority and round-robin arbitration policies. The proposed arbitration policy and the others were implemented through Verilog and mapped the design into Hynix 0.18um technology and compared about gate count and design overhead. In the results of performance analysis, we confirm that our proposed policy outperforms the others in the aspect of design complexity, timing margin, bus utilization, starvation prevention, request cycle and so on.

p38 MAPK Participates in Muscle-Specific RING Finger 1-Mediated Atrophy in Cast-Immobilized Rat Gastrocnemius Muscle

  • Kim, Jung-Hwan;Won, Kyung-Jong;Lee, Hwan-Myung;Hwang, Byong-Yong;Bae, Young-Min;Choi, Whan-Soo;Song, Hyuk;Lim, Ki-Won;Lee, Chang-Kwon;Kim, Bo-Kyung
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.6
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    • pp.491-496
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    • 2009
  • Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.

Research on Anti-Reader Collision Protocols for Integrated RFID-WSNs

  • Ko, Doo-Hyun;Kim, Bum-Jin;An, Sun-Shin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.5
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    • pp.776-796
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    • 2010
  • Integrated RFID-WSNs (wireless sensor networks) have recently been researched to provide object identities, sensing information, mobile service, and network functionalities. In integrated RFID-WSNs, the reader collision is one of the critical problems. Above all, due to the absence of universally applicable anti-collision protocols and the channel capture phenomenon, the medium access control protocols in integrated RFID-WSNs suffer from reader collision and starvation problems. In this paper, we propose an efficient MAC protocol, called EMP, to avoid the above problems in integrated RFID-WSNs. EMP is a CSMA-based MAC protocol which is compatible with sensor networks operating on integrated nodes which consist of an RFID reader and a senor node. EMP resolves not only the reader collision problem, but also the starvation problem using a power control mechanism. To verify the performance of EMP, we compared it with other anti-reader collision MAC protocols using simulations. As a result, the performance of EMP showed improvements in throughput, system efficiency, and energy consumption compared to the single data channel protocols (CSMA/CA, Pulse, and DiCa) in dense deployment environments.

Evaluation of apoptosis after ionizing radiation in feeding and starving rats

  • Lee, Jae-Hyun;Cho, Kyung-Ja;Hong, Seok-Il;Park, Min-Kyung
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.37-46
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    • 1998
  • It has been known that $\gamma$-irradiation usually induces cell death in regenerating stem cell in normal tissues like skin, intestine and hematopoietic organ. The experiment were carried out to evaluate the early response of radiation injury in radiosensitive and intermediate radiosensitive tissues in feeding and starving rats with the doses of 3.5 and 7.0 Gy. The results of the study showed that the histological phenomenon was apoptosis in the doses of the radiation as the early response of tissue injury. Apoptosis were showed organ-specific and cellular specific responses suggesting that the selection of apoptosis be exactly focused on highly renewal organs and cells. It was interesting that the rats starved for 72 hours prior to irradiation induced less apoptosis in liver than fed rats. As for cellular responses it appeared that apoptotic cells were mostly distributed in ductal or periportal cells in liver of feeding rats unlikely in liver of Starving rots which showed no difference in zonal distribution. In salivary gland apoptotic cells in fed rats were highly induced in intercalating and ductal cell population than in acinar cell population although unlikely in starved rats. This study showed the value of apoptosis using the detection system of TUNEL for evaluating cellular damage after radiation injury and the diminished effect of starvation on cell damage after ionizing irradiation.

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Reader Collision Avoidance Scheme for Mobile RFID-Sensor Integrated Networks

  • Ko, Doo-Hyun;Kim, Song-Min;Lee, Sang-Bin;An, Sun-Shin
    • Journal of IKEEE
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    • v.13 no.2
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    • pp.108-117
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    • 2009
  • In recent years, one of alternatives for constructing RFID networks that provide mobile services is using wireless sensor networks (WSN) to enhance network capacity, utility and scalability. Due to absence of compatible reader anti-collision control and channel capture phenomenon, the medium access control protocols as used in the RFID networks lead to reader collision and starvation problem. In this paper, we develop a MAC protocol which is called Enhanced Collision Avoidance MAC (ECO) to avoid reader to reader collisions in an integrated RFID network. ECO is a CSMA-based MAC protocol, and operates on integrated nodes which consist of a RFID reader and a mote. Performance evaluation shows superior results to pure-CSMA protocols under dense deployment environments, both in number of failures and in throughput.

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A Study on the Change in the Film Thickness of Ball Bearing in Starved EHL (윤활유 부족 상태에서의 볼 베어링 유막 두께 변화에 대한 연구)

  • Jung, SoonBi;Lee, Bora;Yu, YongHun;Cho, YongJoo
    • Tribology and Lubricants
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    • v.33 no.3
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    • pp.119-125
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    • 2017
  • In this study, we perform a numerical analysis to predict the film thickness and lubrication regions for a thrust ball bearing under different operating conditions. Film thinning and replenishment affect the film thickness in starved lubrication. As the inlet meniscus position is brought to the edge of the Hertz contact, the thin film thickness is calculated as starved equation. We use a film replenishment model to determine the recovery film thickness between rolling elements. We use a hydrodynamic model to describe film recovery, that results from the effects of surface tension. In this model, we consider the surface tension gradient in fluid depression as the driving force for fluid recovery. We use Fourier transform method to determine the time-dependent depth of depressed oil. We calculate the change in the central film thickness graphically by using the recovery equation in starved elastohydrodynamic lubrication(EHL) under operating conditions that include numbers of balls, sliding velocity, applied force, and ambient film thickness. We evaluate the degree of starvation by using the distance from the center of the contact area to the meniscus position. Parched lubrication, a phenomenon where the film thickness decreases consistently, occurs at the severe condition. We determine optimal values with respect to the numbers of balls, and sliding velocity. The investigation can contribute to the design operating conditions for proper lubrication.