• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3539-3558
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• 2015

This paper investigates and analyzes the default block placement strategy of HDFS. HDFS is a typical representative distributed file system to stream vast amount of data effectively at high bandwidth to user applications. However, the default HDFS block placement policy assumes that all nodes in the cluster are homogeneous, and places blocks with a simple RoundRobin strategy without considering any nodes' resource characteristics, which decreases self-adaptability of the system. The primary contribution of this paper is the proposition of a network load sensitive block placement strategy. We have implemented our algorithm and justify it through extensive simulations and comparison with similar existing studies. The results indicate that our work not only performs much better in the data distribution but also improves write performance more significantly than the others.

• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.647-656
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• 2011

Incidence matrix is a useful tool for presenting incomplete block designs; however, it is inadequate to use only an incidence matrix in examining whether a certain incomplete block design becomes a balanced incomplete block design or not. We can use a structural matrix as a useful tool to show whether a certain incomplete block design becomes a balanced incomplete block design or not. We propose an augmented incidence matrix and ${\lambda}$ matrix as another tools for evaluating incomplete block designs. Through the augmented incidenc matrix and ${\lambda}$ matrix, we can ascertain whether a certain incomplete block design becomes a balance incomplete block design or not.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.33-38
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• 2002

We prove that blocked complete dialler crosses using balance incomplete block design are A-, D-, E-optimal design. Also, we provide such blocked complete dialled crosses and their average efficiency with table.

• IE interfaces
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• v.14 no.4
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• pp.394-402
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• 2001

In this study, we deal a spatial scheduling system for the block painting process in the shipbuilding industry. In general, the spatial scheduling for the block painting process is a very complicated task. Because spatial allocation of each block in blasting and painting cells is considered simultaneously. Thus the spatial scheduling for the block painting process is the problem of planning and control of operation, which arises in shipyard. This system is developed for blocks to meet the delivery date given by the shipyard production planning system, to maximize space utilization of blasting and painting cells and to balance workload among working teams. And it has been tested using actual scheduling data from a shipyard and successfully applied in a paint shop in a shipbuilding company.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.71-76
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• 2022

Round-robin is widely used for the scheduling of large-scale parallel workloads in the computing units of GPGPU. Round-robin is easy to implement by sequentially allocating tasks to each computing unit, but the load balance between computing units is not well achieved in multi-workload environments like cloud. In this paper, we propose a new thread block scheduling policy to resolve this situation. The proposed policy manages thread blocks generated by various GPGPU workloads with multiple queues based on their computation loads and tries to maximize the resource utilization of each computing unit by selecting a thread block from the queue that can maximally utilize the remaining resources, thereby inducing load balance between computing units. Through simulation experiments under various load environments, we show that the proposed policy improves the GPGPU performance by 24.8% on average compared to Round-robin.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.7-12
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• 2014

Objective: The purpose of this study was to investigate the effects of a three dimensional balance trainer in combination with a video-game system and visual feedback on balance recovery and gait function in subacute stroke patients. Design: Randomized controlled trial. Methods: Twenty-three subacute stroke patients were assigned to either an experimental (n=12) or a control group (n=11) using a random permuted block design and sealed envelopes. The experimental group received additional 3-dimensional balance training combined with visual feedback and a game program for 30 min/day, 5 days/week for 4 weeks. Both groups received 30-min of conservative physical therapy sessions based on neurodevelopmental therapy. Before and after the 20 sessions, walking abilities were evaluated by the the GaitRite system and balances were evaluated using the Berg Balance Scale (BBS). The Trunk Impairment Scale (TIS) was used to assess trunk muscle performances. Results: After the 4-week intervention, BBS and TIS scores were significantly increased in both groups (p<0.05), and increases in these scores were significantly greater in the experimental group (p<0.05). After the 4-week intervention, gait speed and cadence were significantly increased in both groups (p<0.05), and as was observed for BBS and TIS scores, changes of gait speed and cadence were significantly greater in the experimental group (p<0.05). Conclusions: The study shows that the 3-dimensional balance trainer combined with visual biofeedback and a video-game system provides a therapeutic means for improving balance and gait ability in subacute stroke patients.

• 한국데이터정보과학회:학술대회논문집
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• 2005.04a
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• pp.69-82
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• 2005

Factorial experiments are studied in this paper. The Designs, thus, have factorial balance with respect to estimable main effects and interactions. John and Lewis (1983) considered generalized cyclic row-column designs for factorial experiments. A simple method of constructing confounded designs using the classical method of confounding for block designs is described in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.209-213
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• 1987

This paper presents decentralized discrete-time system which is optimized by hierarchical control for process automation via the extended interaction balance method. This proposed method can control general matrix which input matrix is not block diagonalization. Also, this paper shows convergence condition of proposed method.

• International Journal of Reliability and Applications
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• v.2 no.2
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• pp.131-135
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• 2001

Two general methods of construction leading to several series of universally optimal block designs for complete diallel crosses are provided in this paper. A method of constructing variance balance designs is also given.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.4
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• pp.107-115
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• 2016

The occurrence of brain stem stroke after lumbar selective nerve root block seem to be an uncommon event comparing it to after cervical selective nerve root block. We recently experienced a 60-year-old man who were diagnosed as left lateral medullary infarction (Wallenberg's syndrome) after lumbar selective nerve root block. He was treated by traditional Korean medicine with acupunture, Pulsed electromagetic therapy (PEMT), herb medicine. The range of motion of upper and lower extremity, manual muscle test, Korean version of Berg balance scale (K-BBS) and Korean version of Barthel index (K-MBI) were adopted to measure the resulting recovery after 4 weeks treatment. Traditional Korean medicine was effective for rehabilitation of patient. Further studies are needed to set up and Korean medical protocol for Wallenberg's syndrome.