• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권7호
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• pp.2815-2839
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• 2020

In a cloud computing paradigm, allocation of various virtualized ICT resources is a complex problem due to the presence of heterogeneous application (MapReduce, content delivery and networks web applications) workloads having contentious allocation requirements in terms of ICT resource capacities (resource utilization, execution time, response time, etc.). This task of resource allocation becomes more challenging due to finite available resources and increasing consumer demands. Therefore, many unique models and techniques have been proposed to allocate resources efficiently. However, there is no published research available in this domain that clearly address this research problem and provides research taxonomy for classification of resource allocation techniques including strategic, target resources, optimization, scheduling and power. Hence, the main aim of this paper is to identify open challenges faced by the cloud service provider related to allocation of resource such as servers, storage and networks in cloud computing. More than 70 articles, between year 2007 and 2020, related to resource allocation in cloud computing have been shortlisted through a structured mechanism and are reviewed under clearly defined objectives. Lastly, the evolution of research in resource allocation techniques has also been discussed along with salient future directions in this area.

• 한국레이저가공학회지
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• 제18권3호
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• pp.1-5
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• 2015

A 3D printer based on laser powder deposition (LPD), also known as DED (direct energy deposition), has been developed for fabricating metal parts. The printer uses a ytterbium fiber laser (1070nm, 1kW) and is equipped with an Ar purge chamber, a three-dimensional translation stage and a powder feeding system composed of a powder chamber and delivery nozzles. To demonstrate the performance of the printer, a tapered cylinder of 320mm in height has been fabricated successfully using Ti-6Al-4V powders. The process parameters including the laser output power, the scan speed, and the powder feeding rate have been optimized. A 3D printed test specimen shows mechanical properties (yield strength, ultimate tensile strength, and elongation) exceeding the criteria to employed in a variety of Ti alloy applications.

• Journal of Information Processing Systems
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• 제16권5호
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• pp.1113-1128
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• 2020

Ad hoc networks play an important role in mobile communications, and the performance of nodes has a significant impact on the choice of communication links. To ensure efficient and secure data forwarding and delivery, an intelligent routing protocol (IAODV) based on learning method is constructed. Five attributes of node energy, rate, credit value, computing power and transmission distance are taken as the basis of segmentation. By learning the selected samples and calculating the information gain of each attribute, the decision tree of routing node is constructed, and the rules of routing node selection are determined. IAODV algorithm realizes the adaptive evaluation and classification of network nodes, so as to determine the optimal transmission path from the source node to the destination node. The simulation results verify the feasibility, effectiveness and security of IAODV.

• 한국정보컨버전스학회:학술대회논문집
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• 한국정보컨버전스학회 2008년도 International conference on information convergence
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• pp.199-204
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• 2008

Sensor nodes have various energy and computational constraints because of their inexpensive nature and ad-hoc method of deployment. Considerable research has been focused at overcoming these deficiencies through faster media accessing, more energy efficient routing, localization algorithms and system design. Our research attempts to provide a method of improvement MAC performance in these issues. We show that traditional carrier-sense multiple access(CSMA) protocols like IEEE 802.11 do not handle the first constraint adequately, and do not take advantage of the second property, leading to degraded latency and throughput as the network scales in size, We present more efficient method of a medium access for real-time wireless sensor networks. Proposed MAC protocol is a randomized CSMA protocol, but unlike previous legacy protocols, does not use a time-varying contention window from which a node randomly picks a transmission slot. To reduce the latency for the delivery of event reports, it carefully decides a fixed-size contention window, non-uniform probability distribution of transmitting in each slot within the window. We show that it can offer up to several times latency reduction compared to legacy of IEEE 802.11 as the size of the sensor network scales up to 256 nodes using widely used simulator ns-2. We, finally show that proposed MAC scheme comes close to meeting bounds on the best latency achievable by a decentralized CSMA-based MAC protocol for real-time wireless sensor networks which is sensitive to latency.

• 대한안전경영과학회지
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• 제15권1호
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• pp.193-198
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• 2013

Warehouse Management System was a helper of business in past, but it is perceived as a core competitive power and a tool for generating new business. It have been come out some new prospects for WMS due to generalization of global outsourcing and extension of the range of supply chain. In China, H automobile company construct the new WMS for providing the production extension and increment of part demand for A/S. This paper deals with the location management in warehouse, warehouse management, delivery management of goods from a warehouse, inventory management organizing WMS for construction of A/S warehouse in H motor in China. Then we identified the several problems of existing warehouse and constructed the driving organization and methods for overcoming these problems. We continually gather data for analysing the effects of new A/S warehouse and WMS construction.

• 경영과정보연구
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• 제5권
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• pp.61-79
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• 2000

This research suggests the strategic adoption methodology of Customer Relationship Management. The backgrounds of CRM is the business environment changing that Market power is shifting to the customer who has unprecedented powers of choice today. The strategic adoption of Customer Relationship Management determines the value, needs and preferences of each customer or customer segment. Customer Relationship Strategy is an explicitly defined plan for how a company has decided to connect with, relate to, and focus on its chosen customers to create value. Deliberate decisions must be made, often involving trade-offs, so that investments are aligned with customer needs and value. Plan defined in terms of target customers value proposition, role in value delivery, and risk/reward sharing. All customers are not created equal; specific customers and/or customers segments are more desirable/valuable to pursue. Key premise of CRM is that value can be created by changing company's business model to better connect with customers. Area of service of Customer Relationship Management are as follows. Portfolio strategy, Market Opportunity Assessment, Brand Equity, Market Positioning, Pricing, Channel Strategy, Market Segmentation. Target Market Identification, Customer LifeTime Value Analysis, Customer Profitability, Customer Connections Economics Analysis. The objects of CRM are maximizing customer service effectiveness, improving customer loyalty, increasing customer service efficiency, optimizing intelligence about customer behaviors and preferences.

• 한국군사과학기술학회지
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• 제18권1호
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• pp.66-83
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• 2015

Global Positioning System(hereafter; GPS) is recently an essential element in the various navigation and weapon delivery systems of military aircraft. However, GPS is vulnerable to the jamming threats since its signal power is very weak. Therefore, ROK defense has been concerning how to resolve this issue and how to integrate these systems needed, and is trying to acquire the proper anti-jamming GPS system. This study is to provide several schemes against the jamming threats effectively. We propose the several processes to analyze the required capability and demonstrate the result's of modeling and simulations(hereafter; M&S) for this integration of military aircraft, and the mathematical programming model for system optimization of military aircraft anti-jamming GPS system on the basis analysis of M&S results which could be considered available budget and the project characteristic. These schemes will be helpful on proper acquisition of these systems and. We are looking forward to contributing to the integration of anti-jamming GPS system of ROK military aircraft.

• ETRI Journal
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• 제37권3호
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• pp.480-490
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• 2015

The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

• 수산경영론집
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• 제46권1호
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• pp.145-155
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• 2015

This study aims to look at the change in consumer awareness and behavior after Japan's 2013 nuclear power plant's radioactive water leakage and draw implications about them. Findings show that 81% of respondents decreased their consumption of fishery products after the nuclear incident, and kept on showing avoidance of imported fishery products including those from Japan. Also it showed that consumers more importantly considered safety when buying imported fishery products after the nuclear incident. The most common channel of receiving radioactivity safety information on fishery products were TV and online. However, the main reason for decreasing the consumption of fishery products was founded to be based on the inaccuracy of the information provided. However, many people said that they will increase their consumption of all fishery products if provided with accurate radioactivity information. Therefore, if accurate radioactivity information were to be spread effectively to the public, positive consumption rates of fishery products can be shown in the future. The inaccuracy of radioactivity safety information caused the rapid decrease of fishery products consumption in 2013 to be amplified. Therefore, this study showed the importance of the delivery of rapid, accurate and consistent information to consumers.

• 수산해양교육연구
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• 제28권5호
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• pp.1329-1338
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• 2016

South Korea's total fertility rate dropped to 1.2 in 2014, which was far below the population replacement level of 2.07. Parental satisfaction of mothers contribute to secondary childbirth intention as well as child outcome. This study was to identify the factors affecting parental satisfaction particularly in mothers with one child. The survey conducted in five daycare centers in B city from September to October in 2015. The data were analyzed with descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficient and stepwise multiple regression analyses using SPSS/Win 21 software. 42.7% of variance in parental satisfaction was accounted for by co-parenting(t=5.566, p<.001), value of children(t=3.575, p=.001), and perception of childbirth(t=2.906, p=.005). The explain power was significant(F=21.581, p<.001). This study revealed that the perception of childbirth last long enough to affect mothers of children up to the age of 6. Midwifes and nurses working with laboring women should try to give them positive experience of delivery.