• International Journal of Contents
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• v.5 no.4
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• pp.88-93
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• 2009

It is important for communication networks to possess the capability to overcome failures and provide survivable services. We address modeling and analysis of performability affected by both performance and availability of system components for a token ring network under failure and repair conditions. Stochastic reward nets (SRN) is an extension of stochastic Petri nets and provides compact modeling facilities for system analysis. In this paper, hierarchical SRN modeling techniques are used to overcome state largeness problem. The upper level model is used to compute availability and the lower level model captures the performance. And Normalized Throughput Loss (NTL) is obtained for the composite ring network for each node failures occurrence as a performability measure. One of the key contributions of this paper constitutes the Petri nets modeling techniques instead of complicate numerical analysis of Markov chains and easy way of performability analysis for a token ring network under SRN reward concepts.

• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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• pp.77-81
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• 2001

The industrial accident in subway of late is increasingly coming to the front as a serious problem of society because a scale of industrial accident is a large size, and powerfulness, while the percent of accident is decreasing as a result of industrial facilities with the largeness of equipment, automation, and high horse-powering. In this paper, a study on the estimation of accident loss prevention cost and risk analysis in subway construction is proposed as an alternative to the techniques currently used in the general construction projects safety. Then the concept of risk evaluation using a risk assessment model is presented to drive value of risk and numerical example for risk analysis. A means for this does grasp the importance of educational factor by way of analyzing the causes of accident through statistical data of labor department, emphasizing the necessity and the importance of safety education, being helpful to act safety by decreasing insecure activity which ranks the majority of accident causes with putting the education program, form, method into practice that are suitable for a place of business.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.754-759
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• 2007

Methodology of ontology building based on Web resources will not only reduce significantly the ontology construction period, but also enhance the quality of the ontology. Remarkable progress has been achieved in this regard, but they encounter similar difficulties, such as the Web data extraction and knowledge acquisition. This paper researches on the characteristics of ontology construction data, including dynamics, largeness, variation and openness and other features, and the fundamental issue of ontology construction - formalized representation method. Then, the key technologies used in and the difficulties with ontology construction are summarized. A software Model-OntoMaker (Ontology Maker) is designed. The model is innovative in two regards: (1) the improvement of generality: the meta learning machine will dynamically pick appropriate ontology learning methodologies for data of different domains, thus optimizing the results; (2) the merged processing of (semi-) structural and non-structural data. In addition, as known to all wetland researchers, information sharing is vital to wetland exploitation and protection, while wetland ontology construction is the basic task for information sharing. OntoMaker constructs the wetland ontologies, and the model in this work can also be referred to other environmental domains.

• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.129-138
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• 1996

In the result of Industrial development. largeness and highness of techniques. a large amount of Information Is being treated every year. Achive informationization. we must store in computer ,all informations written on paper for a long time and be able to utilize them In right time and place. There Is recurrent neural network as a model rousing the output value In learning neural network for characters recognition. But most of these methods are not so effectively applied to it. This study suggests a new type of recurrent neural network to classifyeffectively the static patterns such as off-line handwritten characters. This study shows that this new type Is better than those of before in recognizing the patterns. such as figures and handwritten characters, by using the new J-E (Jordan-Elman) neural network model in which enlarges and combines Jordan and Elman Model.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.633-636
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• 2015

KaVA (KVN and VERA Array) is a new combined VLBI array composed of KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). Here, we report the following two issues. (1) We review the initial results of imaging observations of M87 at 23 GHz following Niinuma et al. (2014). The KaVA images reveal extended outflows including complex substructures such as knots and limb-brightening, in agreement with previous VLBI observations. KaVA achieves a high dynamic range of ~1000, more than three times better than that achieved by VERA alone. (2) Based on subsequent observations and discussions led by the KaVA AGN SubWorking Group, we set monitoring observations of Sgr $A^{\ast}$ and M87 as our Key Science Project (hereafter KSP) because of the closeness and largeness of their central super-massive black holes. The main science goals of the KSP are (i) testing the magnetically-driven-jet paradigm by mapping velocity fields of the M87 jet, and (ii) obtaining tight constraints on physical properties of the radio emitting region in Sgr $A^{\ast}$. Towards KSP, we show the first preliminary images of M87 at 23 GHz and Sgr $A^{\ast}$ at 43 GHz with the bandwidth of 256 MHz.

• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.9-15
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• 2006

To obtain realistic composite performance and availability measures, one should consider performance changes that are associated with failure recovery behavior. In this paper we address two modeling approaches, exact composite and approximate, and develop SRN models for these approaches. The former approach is to combine the performance and availability models and yields accurate results but generally faces largeness problem. To avoid the problem, the two level hierarchical model is developed. The upper level model describes the failure and repair behavior of the system and the lower level captures the pure performance aspect of the system, channel allocation and service. It models guard channel and preemptive handoff scheme. As numerical results, blocking and dropping probabilities are given for new call and handoff call, respectively.

• Journal of the Korean Solar Energy Society
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• v.39 no.1
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• pp.51-58
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• 2019

This paper deals with the operation of a hybrid power generation system made with photovoltaic cells and piezoelectric materials. The system can produce power from the wind as well as from the sun subject to their availability. Irrespective of the largeness of their power production, the power developed by both generators (i.e., phtovoltaic cells and piezoelectric cells) were combined and stored before it was applied to a load. Especially, the AC power (current) developed from each piezoelectric generator was converted by a full wave bridge rectifier and then combined prior to its storage in a capacitor. It was observed that the system can produce a maximum output power of 6.49 mW at loading resistance of $100{\Omega}$.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.604-613
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• 2016

The sea level of the Earth is rising approximately 2.0mm per year (global average value) due to thermal expansion of sea water, melting of glaciers and other causes by global warming. However, when it comes to design a river, the standard of design water level is decided by analyzing four largeness tide value and harmonic constant with observed tidal water level. Therefore, it seems the external water level needs to consider an increasing speed of the seawater level which corresponds to a design frequency. In the present study, the hourly observed tidal water level targeting 47 tidal stations operated by Korea Hydrographic and Oceanographic Administration (KHOA) from beginning of observation to 2015 per hour has been collected. The variation of monthly and yearly and increasing ratio have been performed divided 4 seas such as the Southern, East, Western, and Jeju Sea. Also, the external water level existing design for rivers nearby a coast was been reviewed. The current study could be used to figure out the cause of local seawater rise and reflect the external water level as basic data.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.295-301
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• 2006

An operational strategy for inventory control on finished goods in the distribution system has been given attention to many enterprises and many studies regarding this field have been done and is also on-going currently. It handling large scale of smallness type are so the requisition of customer which is various that over it continues more full scale merit. therefore, It is a tendency that many of enterprise is handling small scale of smallness type for environment change confrontation. but It is not easy for the enterprise to In customer demand diversification suiting because too need many cost. In addition, at enterprise charge extra weight because remainder inventory is causes of defective stock for a inefficient problem solution. this paper is rationalization of stock cost decrease for comparison evaluation of small scale quantify handling of singleness type and small scale quantity handling of largeness type.

• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.99-103
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• 2008

An operational strategy for inventory control on finished goods in the distribution system has been given attention to many enterprises and many studies regarding this field have been done and is also on-going currently. It handling large scale of smallness type are so the requisition of customer which is various that over it continues more full scale merit. therefore, It is a tendency that many of enterprise is handling small scale of smallness type for environment change confrontation. but It is not easy for the enterprise to In customer demand diversification suiting because too need many cost. In addition, at enterprise charge extra weight because remainder inventory is causes of defective stock for a inefficient problem solution. this paper is rationalization of stock cost decrease for comparison evaluation of small scale quantity handling of singleness type and small scale quantity handling of largeness type.