• International journal of advanced smart convergence
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• v.13 no.3
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• pp.31-40
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• 2024

The proliferation of video streaming services has led to a need for flexible networking protocols. As a result, the Dynamic Adaptive Streaming over HTTP (MPEG-DASH) protocol has emerged as a dominant streaming protocol due to its ability to dynamically adjust playback bitrates according to the end-user's network conditions. In this paper, we propose a novel I/O scheduling scheme tailored for the storage of MPEG-DASH-enabled video servers. Using the renowned rate-reservation (RR) algorithm and bulk-SCAN mechanism, our proposed scheme improves storage bandwidth utilization while ensuring seamless playback of streams with varying bitrates. In addition, we provide a mechanism for reclaiming the idle I/O time typically incurred while retrieving video segments from storage. Consequently, our scheme offers practical solutions for reducing the storage costs of MPEG-DASH video servers. With a simple cost model, we evaluate the performance enhancements achieved by our proposed I/O scheduling scheme.

• Journal of Korea Multimedia Society
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• v.2 no.4
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• pp.378-389
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• 1999

Parallel tasks in distributed real-time systems can be divided into several subtasks and be executed in parallel according to their real-time attributes. But, it is difficult to gain the optimal solution which is to allocate a tasks deadline into the subtasks deadline while minimizing the subtasks deadline miss. Tn this Paper, we propose the algorithm that allocates deadlines into each subtask, according to the attributes of each subtask(i.e. using communication time and execution time to periodic tasks). Also, we suggest a processor mapping algorithm that considers the communication time among the processors and the effective duplication algorithm which is allocated to the identical processor for the purpose of improving the communication time between the subtasks. We can obtain a result that reduces IPC(Inter-Processor Communication) time and uses the idle processor through applying effective real-time attributes to FUTD(Fully connected, Unbounded Task Duplication) algorithms. As a result, we can improve the average processor utilization.

• Journal of Animal Environmental Science
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• v.3 no.2
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• pp.87-95
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• 1997

This study was peformed to compare work routine time and performance of milking systems by measuring motion and time in milking procedure. Data were collected from thirteen dairy farms among which milking was done by bucket in two farms, by pipelines in three, by tandem parlors in four including one remodeled side-opening, by herringborn parlors in three and by a parallel milking parlor. Recording time and motion for milking parlor. Recording time and motion for milking procedure was performed by stopwatch and notebook computer. Work routine elements were recorded and calculated into cows milked per-man-hour(CMPH). The results are as follows : Average milking time per cow(MTPC) in bucket and pipeline milking systems usually installed in cow stall were 442.7 and 395.8 seconds, respectively. And average CMPH of bucket and pipeline milking system were 144.5, 303.3, 272.5 and 380.3 seconds, respectively. And CMPH of tandem, herringbone, parallel and modified side-opening systems were 24.9, 11.9, 13.2 and 9.5 heads, respectively. CMPH was the highest in the tandem milking system and the lowest in the bucket milking facilities. CMPH, when milked in a parlor resulted in high value compared with bucket or pipeline milking systems installed in cow stable. They showed considerably low CMPH compared with the results of other countries. The reason why so low CMPH could be derived from type and mechanization of facilities and equipment, operator's ability, number of operator, idle time and milking procedure.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.2
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• pp.29-39
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• 2018

In this paper, we discuss a discrete-time queueing system with dyadic server control policy that combines workload control and multiple vacations. Customers arrive at the system with Bernoulli arrival process. If there is no customer to serve in the system, an idle single server spends a vacation of discrete random variable V and returns. The server repeats the vacation until the total service time of waiting customers exceeds the predetermined workload threshold D. In this paper, we derived the steady-state workload distribution of a discrete-time queueing system which is operating under a more realistic and flexible server control policy. Mean workload is also derived as a performance measure. The results are basis for the analysis of system performance measures such as queue lengths, waiting time, and sojourn time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.71-76
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• 2021

Recently, as the size of IoT data grows, the memory power consumption of real-time systems increases rapidly. This is because real-time systems always place entire tasks in memory, which increases the demand of DRAM significantly. In this paper, we adopt emerging fast storage media and move a certain portion of real-time tasks from DRAM to storage. The part of tasks in storage are, then, loaded into memory when they are actually used. We incorporate our memory/storage power-saving into the dynamic voltage/frequency scaling of processors, thereby optimizing power consumptions in CPU and memory simultaneously. Specifically, the proposed technique aims at minimizing the CPU idle time and the DRAM memory size by determining appropriate voltage modes of CPU and the swap ratio of memory, without violating the deadlines of all tasks. Through simulation experiments, we show that the proposed technique significantly reduces the power consumption of real-time systems.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.596-600
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• 2013

We report here on the processing and manufacturing of thin film for printed electronics by micro-gravure coating system. The micro-gravure coating systems are consisted of various modules such as web and system tension controller, micro-gravure coating units, dispenser and hybrid dry units (UV, NIR, Hot air). Especially, for the optimization of system, the number of idle roller was minimized and tension isolating infeeder was included. Also, we applied four patterns circle, 45 degree, square and 35 degree for the optimizing coating thickness. The micro-gravure coating system which applied various patterns to enable continuous coating process and fast coating time compare with conventional batch coating system. In this paper, introduce of micro-gravure coating system and testing results of coating thickness (20~700nm), coating time (1~2sec) and surface roughness (3~12nm) by using micro-gravure coating system.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.214-222
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• 2016

Changes in road infrastructure affect driving patterns and pollutant emission characteristics. we analyzed the changes in driving patterns and pollutant emission characteristics of the driving route via measured driving patterns at year 2009 and 2016. Since 2009, there has been an increase in population and traffic demand, including residential areas and industrial facilities. Traffic conditions were improved such as the opening of the highway Inter-Change to Seoul and the construction of underground driveway. As a result, the average vehicle speed increased. More detail comparisons have made on the changes of the underground driveway section and the crossroad section, which are expected to have significant changes in the transportation infrastructure. The vehicle speed distribution of the underground driveway changed from low speed to high speed, and the increase of the time spent at the high speed and high load caused the increase of NOx emissions. The vehicle speed also increased at the crossroad section, and the consequence NOx and $CO_2$ emissions decreased. It is mainly because the decreased time spent at idle, which results from the proper traffic demand management at this area.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.37-44
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• 1978

The purpose of this study is to search for an efficient application method in solving delay-phenomenon problems which influence upon total production cost through case study. The method of this study is an experimental study based on cutting time data in lead cutting operations from "Lead Cutting Machine (Stripper)" and its service rate data from a large electronic products company which utilizes conveyor line system for the products "Car Stereo" The procedure of this experimental study is as follows; 1) Using loading(Man-Hour) analysis technique j,1 order to analyse and evaluate Production capacity, efficiency, operation and idle rate assembly charge, waiting and service cost -when its are controlled by stripper operator(server) 2) Establishing adequate waiting time model of finite population caused by the interference of 4 stripper machine which is drawn from mathematical statistics testing, that is, goodness of fit test in the waiting and service rate and to search for optimal solution by utilizing the above mentioned model The experimental result was that amount to 8,546,618won Per year was brought down, that is, by optimum point, it shows a decrease as compared with Present point. The major limitation of this experimental study is that the Queue in the Finite Population, so to speak. it comes from the interference of 4 stripper machine dealt with this case were limited only on the Car Stereo conveyor line. Further study of application of this application method to the areas such as material handling, personnel management marketing and transportation management is strong1y recommended.trong1y recommended.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.59-62
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• 2000

Many of the previous researchers have been studied for the performance estimation of an AS/RS with a static model or computer simulation. Especially, they assumes that the storage/retrieval (S/R) machine performs either only single command (SC) or dual command (DC) and their requests are known in advance. However, the S/R machine performs a SC or a DC. or both or becomes idle according to the operating policy and the status of system at an arbitrary point of time. In this paper, we propose a stochastic model for the performance estimation of a unit-load AS/RS by using a M/G/1 queueing model with a single-server and two queues. Expected numbers of waiting storage and retrieval commands, and the waiting time in queues for the storage and retrieval commands are found

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.181-188
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• 2004

PDF(Parallel/Distributed Processing) is an internet-based parallel/distributed processing system that utilizes resources from hosts on the internet in idle state to perform large scale application through parallel processing, thus decreasing the total execution time. In this paper. do propose an adaptive method to be changed network environment at any time using realtime monitoring of host. It is found from experiments that parallel/distributed processing has better performance than its without monitoring as an adaptive strategy, which copy with task delay factor by overload and fault of network, be applicable to the cockpits of task allocation algorithm in PDP.