• Title/Summary/Keyword: Wait cycle

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Bus Arbitration Considering Waiting cycle (대기사이클 고려 버스중재방식)

  • Lee, Kook-Pyo;Joung, Yang-Hee;Kang, Seong-Jun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2703-2708
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    • 2014
  • The conventional bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in arbitrating the bus. The efficiency of bus usage can be determined by the selection of arbitration method. Fixed Priority, Round-Robin, TDMA and Lottery arbitration policies are studied in the conventional arbitration method where the bus transaction cycle, the wait cycle and the priority are primarily considered. In this paper, we propose the arbitration method that considers the wait cycle. Furthermore, we verify the bus transaction cycle and the wait cycle compared with the other arbitration methods through TLM(Transaction Level Model).

A Translation Method from Control Flow Descriptions in cycle-accurate level to Synthesizable RTL VHDL Descriptions (Cycle 수준의 Control Flow Description에서 합성 가능한 VHDL 기술로의 변환 방법에 관한 연구)

  • 윤창열;장경선
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.819-822
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    • 2003
  • This paper defines an algorithmic description language in cycle-accurate level which can be used to design hardware components. The proposed language is less complex and more flexible than VHDL language. In that the language includes C-like control flow descriptions and brief timing information(i.e. clock cycle boundaries) indicated by 'wait_edge' statements. We generate RTL VHDL codes from the descriptions. The proposed language requires only 10~30% of the # of lines to describe the same functionality compared with RTL VHDL.

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Timed-Transfer of Buses (동시환승(Timed-Transfer) 버스시스템)

  • 고승영
    • Journal of Korean Society of Transportation
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    • v.13 no.4
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    • pp.105-115
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    • 1995
  • This paper deals with an operation concept of "time-transfer of buses", in which buses arrive a transfer center at the same time and allow passengers to transfer to other bus lines, so that passengerscan go anywhere all the timed-transfere buses operate with only one transfer. This timed-transfer bus system is known as an efficient operating technique which can be adopted in an area with sparsely distrubuted bus demand. A model of timed-transfer is estabilished in terms of vaious factors such as the expected(or average) arrival time, distribution of arrival time, timed-transfer cycle, shceduled departure time, etc. It is assumed that the objective of timed-transfer bus system is to minimize the total transfer waiting time. The optimal schedualed arrival time or buffer time(time required to arrive ealy in consideration of delay) is analyzed for a general case and various speicial cases. It was found that the optiaml buffer time is an inverse funcion of the timed-transfer cycl and increases with the cycle time, assumin g that there is a fixed scheduled departure time at the transfer cetner regardless of whether one or more buses fail to arrive before the scheduled departure time. If buses are to wait uhtil all the buses arrive at the transfer center, that is, the transfer departure time is vairable, the optimal scheduled arrival times can be obtained by a mathmatical programming.

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PLUTONIUM MANAGEMENT OPTIONS: LIABILITY OR RESOURCE

  • Bairiot, Hubert
    • Nuclear Engineering and Technology
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    • v.40 no.1
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    • pp.9-20
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    • 2008
  • Since plutonium accounts for 40-50% of the power produced by uranium fuels, spent fuel contains only residual plutonium. Management of this plutonium is one of the aspects influencing the choice of a fuel cycle back-end option: reprocessing, direct disposal or wait-and-see. Different grades and qualities of plutonium exist depending from their specific generation conditions; all are valuable fissile material. Safeguard authorities watch the inventories of civil plutonium, but access to those data is restricted. Independent evaluations have led to an estimated current inventory of 220t plutonium in total (spent fuel, separated civil plutonium and military plutonium). If used as MOX fuel, it would be sufficient to feed all the PWRs and BWRs worldwide during 7 years or to deploy a FBR park corresponding to 150% of today' s installed nuclear capacity worldwide, which could then be exploited for centuries with the current stockpile of depleted and spent uranium. The energy potential of plutonium deteriorates with storage time of spent fuel and of separated plutonium, due to the decay of $^{241}Pu$, the best fissile isotope, into americium, a neutron absorber. The loss of fissile value of plutonium is more pronounced for usage in LWRs than in FBR. However, keeping the current plutonium inventory for an expected future deployment of FBRs is counterproductive. Recycling plutonium reduce the required volume for final disposal in an underground repository and the cost of final disposal. However, the benefits of utilizing an energy resource and of reducing final disposal liabilities are not the only aspects that determine the choice of a back-end policy.

Analysis of the S-MAC/T-MAC Protocol for Wireless Sensor Networks (무선 센서망의 에너지 효율적 MAC(S-MAC/T-MAC) 성능 분석)

  • Lee Woo-Chul;Lee Yoo-Tae;Kim Dong-Il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.99-103
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    • 2006
  • In this paper, we focus on the problem of designing an energy efficient MAC protocol for wireless sensor networks and analyze S(Sensor)-MAC and T(Time-out)-MAC. S-MAC is based on the concept of the 'listen/sleep mode cycle'. This applies message passing to reduce contention latency for sensor-network applications that require store-and-forward processing as data moves through the network. However unlike the S-MAC, where the duration of the cycle is fixed, T-MAC introduces an adaptive duty cycle in a novel way: by dynamical ending the active part of it. This reduces the amount of energy wasted on idle listening, in which nodes wait for potentially incoming messages while still maintaining a reasonable throughput. In this paper we discuss the design of these two Protocols. We analyze them from the aspect of latency, throughput, and power savings when using the OMNeT++ simulator in various environments.

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An R-tree Index Scheduling Method for kNN Query Processing in Multiple Wireless Broadcast Channels (다중 무선 방송채널에서 kNN 질의 처리를 위한 R-tree 인덱스 스케줄링 기법)

  • Jung, Eui-Jun;Jung, Sung-Won
    • Journal of KIISE:Databases
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    • v.37 no.2
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    • pp.121-126
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    • 2010
  • This paper proposes an efficient index scheduling technique for kNN query processing in multiple wireless broadcast channel environment. Previous works have to wait for the next cycle if the required child nodes of the same parent node are allocated in the same time slot on multiple channel. Our proposed method computes the access frequencies of each node of R tree at the server before the generation of the R-tree index broadcast schedule. If they have high frequencies, we allocate them serially on the single channel. If they have low frequencies, we allocate them in parallel on the multiple channels. As a result, we can reduce the index node access conflicts and the long broadcast cycle. The performance evaluation shows that our scheme gives the better performance than the existing schemes.

Feeding Habits of the Kaloula borealis during the Breeding Season (번식기간중 맹꽁이(Kaloula borealis)의 먹이 습성)

  • Ko, Sang-Beom;Chang, Min-Ho;Yang, Kyoung-Sik;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.26 no.3
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    • pp.333-341
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    • 2012
  • To investigate the feeding habits of the Kaloula borealis, the stomach contents of 52 out of 56 specimens collected around Daejung-up, Jeju Island in June 2011 were studied. The stomach contents were analyzed with the stomach flushing method. According to the results, the main preys of the Kaloula borealis were Diptera sp., Harpalidae, Formicidae and Drosophilidae. the Kaloula borealis of all sizes fed on small preys, while individuals with large SVL fed on big preys. By feeding on a large amount of food with a small number of activities, the individuals with large SVL is considered to enhance energy efficiency. In many cases, the Kaloula borealis fed on Diptera sp. or Drosophilidae, which are slow but active and capable of flying. As a result, the Kaloula borealis take the sit-and-wait form of preying rather than actively searching for food. The results of this research on feeding habits of the Kaloula borealis will provide valuable resources to protect the endangered Kaloula borealis experiencing a sharp decline in their population and to prepare plans for population preservation strategies for them.

A Study on the RAM Analysis for Effective Integrated Logistics Support(ILS) (효과적인 종합군수지원을 위한 RAM 분석 연구)

  • Lee, Young Uk
    • Convergence Security Journal
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    • v.16 no.6_1
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    • pp.67-74
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    • 2016
  • The development of weapon systems that look only be introduced as a huge budget directly related to combat rea diness. If we develop the expensive equipment it will not be the same state or have to wait a lot of time in mainten ance facilities for maintenance, which will have a profound impact on the exercise Efficiency. In order to solve this problem, the operation and use state of the weapon system requires effort to successfully p erform the duties held by the defined and assigned, Further analysis should be conducted RAM in order to reduce m aintenance manpower and logistic support costs. The role of business is to increase the RAM system reliability by L ee to Fig system failure rate from the development and maintenance, and reduced life cycle costs. Therefore, the present study was to determine the RAM to perform analysis procedures and methods and limita tions of each element, such as to maximize the effectiveness of comprehensive logistics support and help to study to become an effective logistics support.

Study on the Installation warrants of staggered crosswalk traffic island on Urban Streets - Focusing on pedestrian safety and service level - (도시부가로 이단 횡단보도 교통섬 설치 준거에 관한 연구 - 보행자 안전과 서비스수준을 중심으로 -)

  • Shim, Kwan-Bo;Kim, Joong-Hyo;Park, Kyung-Woo;Ha, Dong-Ik
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.6
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    • pp.97-107
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    • 2013
  • On the Staggered Crosswalks, pedestrians cross the crosswalks two times. This method can reduce the cycle, the vehicle delay and the walking distance by increasing the major direction of green time. The safety of pedestrians is also effective. This study suggests the warrant of the facilities of island width and length etc. by considering the road structure and pedestrians. Also this study suggests the standard of the safety through the accident analysis of Staggered crosswalks and General Crosswalks. In the results, accident rate of the Staggered Crosswalks 18.3(100 million vehicle-km) was lower than the accident rate of the General Crosswalks 28.3(100million vehicle-km). By understanding the start point of crossing of the Staggered Crosswalks, the analysis of the location and types of accident suggests the safety zone(spare space). The setting warrants of Staggered Crosswalks are 4 lane over the road and the 2 meter over sidewalk width of island. The minimum length of the Pedestrian island was doubled compared to the crosswalks width. And the maximum length was set by considering the wait time of the pedestrians.

Development of the Better Soil Conservation Measures with Special References to Yam Hillside Farming (경사지(傾斜地) 농업기술(農業技術) 개량(改良)을 위한 효과적(效果的)인 토양보전공법(土壤保全工法) 개발(開發)에 관한 연구(硏究))

  • Woo, Bo Myeong
    • Journal of Korean Society of Forest Science
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    • v.54 no.1
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    • pp.60-67
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    • 1981
  • The run-off experiment plots had been established for eight sets of plot comprising four treatments with two replications on $20^{\circ}$ slope land having the Wait-A-Bit Clay soil(locally known), at the Olive River Soil Conservation Centre, Trelawny in Jamaica. The location of plots was about 820 metres m.s.l. and sloped north-west. Each plot size was determined as $40m^2$ having 2.7 m wide and 15.8 m long along slope. All of the run-off soil and water were collected by using the receiving tanks through the collection troughs and conveyance pipes. These run-off materials were measured and sampled, dried and computed for determination of the soil loss from each treatment of plots. During the first period of experiment for about 10 month which was one crop-year cycle of yam crop, total amount of 1,295 mm rainfall received. The heaviest daily rainfall was recorded as 116.2 mm on August 5 followed by 100.4 mm on August 6, 1980. The soil sediment had been collected and analysed for eleven times during this experiment. Total amounts of soil sediment as over-dried weight by the treatment plot were estimated as 182 ton/ha from treatment I, 105 tons/ha from treatment II, 50 tons/ha from treatment III, 43 tons/ha from treatment IV respectively. It is recommendable at present that the treatment III and IV measure which treated with contour mounds with the hillside ditch and grass buffer strip should be adopt4ed for hillside farming particularly with yam cultivation in Jamaica.

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