• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.107-112
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• 2015

HIGHT is an 64-bit block cipher, which is suitable for low power and ultra-light implementation that are used in the network that needs the consideration of security aspects. This paper presents a parallel key scheduler that generates the whitening keys and subkeys simultaneously for both encryption and decryption processes. We construct the reverse LFSR and key generation blocks to generate the keys for decryption process. Then, the new key scheduler is made by sharing the common logics for encryption and decryption processes to minimize the increase in hardware complexity. From the simulation results, the logic size is increased 1.31 times compared to the conventional HIGHT. However, the performance of HIGHT including the proposed key scheduler can be increased by two times compared to the conventional counterpart.

• IE interfaces
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• v.11 no.2
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• pp.13-24
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• 1998

A distribution system is composed of multiple levels from a producer to customers, and it's objective is to supply customers with goods timely with a prescribed level of quality at a minimum cost. For the installation and operation of multi-echelon distribution system, DRP(Distribution Resource Planning) is widely used. However, because of the characteristic difference of material flow dynamic of each distribution center, it is almost impossible to get the optimal distribution scheduling. In this paper, an improved DRP method to schedule multi-echelon distribution network is proposed so that the lot-size and order point is dynamically obtained to meet the change of demand rate and timing. The experiment is done with various demand pattern, forecast errors of demand and lead times of central distribution center. The proposed method is compared with traditional statistical approach.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2096-2100
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• 2008

This research project management, building systems to test the performance requirements of a user to accept the plan and schedule management, personnel management, and test results, and the status of testing and reporting procedures to handle the process of implementation of Java-based X - Under the Internet environment, the default network, remote process research and development program as a test automation, structure and each module of the software analysis, design, analysis and clean-up and structure of the modules, each module and the GUI structure, performance, testing integration DB The present system is to study the system.

• ETRI Journal
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• v.41 no.3
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• pp.326-336
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• 2019

A wireless power transfer technique can solve the power capacity problem in wireless rechargeable sensor networks (WRSNs). The charging strategy is a wide-spread research problem. In this paper, we propose a demand-based charging strategy (DBCS) for WRSNs. We improved the charging programming in four ways: clustering method, selecting to-be-charged nodes, charging path, and charging schedule. First, we proposed a multipoint improved K-means (MIKmeans) clustering algorithm to balance the energy consumption, which can group nodes based on location, residual energy, and historical contribution. Second, the dynamic selection algorithm for charging nodes (DSACN) was proposed to select on-demand charging nodes. Third, we designed simulated annealing based on performance and efficiency (SABPE) to optimize the charging path for a mobile charging vehicle (MCV) and reduce the charging time. Last, we proposed the DBCS to enhance the efficiency of the MCV. Simulations reveal that the strategy can achieve better performance in terms of reducing the charging path, thus increasing communication effectiveness and residual energy utility.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.534-537
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• 2009

Clustering protocol of Wireless sensor networks(WSNs) can not only reduce the volume of inter-node communication by the nodes's data aggregation but also extend the nodes's sleep times by cluster head's TDMA-schedule coordination. In order to extend the network lifetime of WSNs, we propose CHS algorithm to select cluster-head using three variables. It consists of initial and current energy of nodes, round information, and total numbers which have been selected as cluster head until current round.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1118-1123
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• 2005

This paper proposes the CPM bar chart (CBC), a hybrid of the bar chart and the critical path method (CPM). The CBC overcomes shortages of the fence bar chart, while still retaining its advantages. The fence with direction is applied instead of the broken fence, which triggers considerable problems to identify and apply in the fenced bar chart. In addition, the notorious task to find dummy activities is no longer required. Upon the benefits of simplicity in the bar chart and logical work sequence in the CPM network, the CBC provides a relatively easy way to create and understand a schedule, thus improving communication quality between project participants.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1643-1651
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• 1999

Video-On-Demand (VOD) is expected to provide the user with interactive operations such as VCR functions. In particular, fast scan functions like “Fast Forward” of “Fast Backward” for a certain speedup playback are required. Since they require a significant amount of system resources, schemes to reduce bandwidth requirements for the network or disk are needed. In MPEG standard, Group-of-Pictures (GoP) is a random access unit which can be decoded independently. Since storing and transmitting a video stream based on GoP is efficient, it is practical to support fast scan functions based on GoP. In this paper, we present a dynamic transmission scheduling scheme to support fast scan functions with m-times normal playback rate for a stored video. The proposed scheme writes a transmission schedule whenever user requests a fast scan function. That is, the scheme constructs the data set to be smoothed by skipping GoPs according to a given speedup factor, and then writes the transmission schedule by applying a bandwidth smoothing. Finally, the scheme restarts the transmission of video data to a client according to the new schedule. The proposed scheme results in speeding up the playback rate by utilizing “GoP skipping”, and then reduces the computational overhead by applying a bandwidth smoothing based on GoP.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.120-127
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• 2012

Today, most construction projects have been higher, bigger, and more complicated gradually. So the domestic construction companies have been trying to understand overall construction process and relationships between activities, and adopted various management techniques and tools in order to perform a systematic and effective scheduling. However numerous problems have been occurred on the practical applications because most existing scheduling softwares adapt ADM and PDM techniques. One of them, PDM, is so uneffective because it represents the overlapping relationships between two consecutive activities only by the combinations of start and finish points between two activities. In order to supplement the demerit of PDM, Beeline Diagramming Method(BDM) is proposed as a new networking technique, it can represent two-way multiple overlapping relationships between two activities directly. However there are occurring a loop phenomenon on applying two-way multiple overlapping relationships. This research proposes and verifies the schedule computation method of two-way multiple overlapping relationships on the BDM network.

• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.117-129
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• 2008

The cost-based scheduling work has been done in both the Operations Research (OR) and Artificial Intelligence (AI) literature. To deal with more realistic problems, AI-based heuristic scheduling approach with non-regular performance measures has been studied. However, there has been little research effort to develop a full inter-job cost propagation algorithm (CPA) for different jobs having multiple downstream and upstream activities. Without such a CPA, decision-making in scheduling heuristics relies upon local, incomplete cost information, resulting in poor schedule performance from the overall cost minimizing objective. For such a purpose, we need two types of CPAs : intra-job CPA and inter-job CPA. Whenever there is a change in cost information of an activity in a job in the process of scheduling, the intra-job CPA updates cost curves of other activities connected through temporal constraints within the same job. The inter-job CPA extends cost propagation into other jobs connected through precedence relationships. By utilizing the cost information provided by CPAs, we propose cost-based scheduling heuristics that attempt to minimize the total schedule cost. This paper develops inter-job CPAs that create and update cost curves of each activity in each search state, and propagate cost information throughout a whole network of temporal constraints. Also we propose various cost-based scheduling heuristics that attempt to minimize the total schedule cost by utilizing the cost propagation algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.617-625
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• 2008

In low-density areas where travel pattern is widely dispersed and travel demand is relatively low, transit operators find it very difficult to provide a reasonable level of service at a reasonable cost. Timed-transfer system or network, if designed properly, can provide a reasonable level of service for passengers using transit systems serving low-density areas. The paper intends to apply a timed-transfer system for bus lines serving Yangsan City area and to assess the effects resulted from the application. The concept of a timed-transfer network/system is briefly described, and the present conditions of bus systems in Yangsan City area are discussed, focusing on the aspects of network type and the related problems. The bus timed-transfer network for the area is then developed by adjusting the existing routes and network with the consideration of travel time, route alignments, headways and transfer centers. One must note that developing a timed-transfer network presumes that network and schedule should be developed together. The effects of the developed time-transfer system on the passengers and operators are found substantially so as to justify its introduction to the City. The results of this study will be of considerable use for planners to design the transit systems in low density areas, where in general travel activities are widely dispersed and travel demands are low, so that provision of good quality of transit services are difficult.