• Journal of Digital Contents Society
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• v.6 no.1
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• pp.1-5
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• 2005

This paper describes the main characteristics of Grid Services based on OGSA and a Grid service for aggregating service data element(SDE)s. In order to build a Grid Service, it needs to consider a systematic building approach from the high-level software architecture that represents the main system components and their interactions. The purpose of this paper is to design and implement an extended service data aggregator service in which SDE is a basic unit for collecting resource information. A GT3 based service data aggregator service is extended to apply the multiple collections based storage scheme for maintaining persistently SDEs with a XML DBMS Xindice. To provide efficient aggregating service for service data elements, which is running under wide area environment like Internet, the aggregator service is asynchronously operated by notification mechanism.

• Transactions of the Korean hydrogen and new energy society
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• v.4 no.2
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• pp.29-40
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• 1993

Intensive studies on the electrochemical characteristics of TiFe type alloy electrodes have been carried out to clarify the mechanism of electrochemical hydrogen absorption and desorption. It was found that electrochemical activation of the TiFe type alloys is difficult and that charge efficiencies are very low even after a decade of activation cycles. However, by the pretreatment of the powders such as gas activation and/or Ni chemical plating, charge efficiencies fairly increased, especially for the $TiFe_{0.8}Ni_{0.2}$ alloy. It was considered that difficulties to activation and lower charge efficies of the alloys are due to the presence of the passivation films, which prohibit inward diffusion of hydrogen and promote the combination of adsorbed hydrogen atom to gas bubbles during the electrochemical charge. In addition, lower diffusivity of hydrogen in the alloys may be played an important role lowering the charge efficiencies.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.3
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• pp.143-148
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• 2018

In this paper, the optimal fuzzy logic controller(FLC) for a hybrid renewable energy system(HRES) is proposed. Generally, hybrid renewable energy systems can consist of wind power, solar power, fuel cells and storage devices. The proposed FLC can effectively control the entire HRES by determining the output power of the fuel cell or the absorption power of the electrolyzer. In general, fuzzy logic controllers can be optimized by classical optimization algorithms such as genetic algorithms(GA) or particle swarm optimization(PSO). However, these FLC have a disadvantage in that their performance varies greatly depending on the control parameters of the optimization algorithms. Therefore, we propose a method to optimize the fuzzy logic controller using the teaching-learning based optimization(TLBO) algorithm which does not have the control parameters of the algorithm. The TLBO algorithm is an optimization algorithm that mimics the knowledge transfer mechanism in a class. To verify the performance of the proposed algorithm, we modeled the hybrid system using Matlab Tool and compare and analyze the performance with other classical optimization algorithms. The simulation results show that the proposed method shows better performance than the other methods.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.824-830
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• 2003

RPA (Recursive Partition Averaging) method was proposed in order to improve the storage requirement and classification rate of the Memory Based Reasoning. That algorithm worked well in many areas, however, the major drawbacks of RPA are it's pattern averaging mechanism. We propose an adaptive OHC algorithm which uses the FPD(Feature-based Population Densimeter) to increase the classification rate of RPA. The proposed algorithm required only approximately 40% of memory space that is needed in k-NN classifier, and showed a superior classification performance to the RPA. Also, by reducing the number of stored patterns, it showed a excellent results in terms of classification when we compare it to the k-NN.

• Journal of Information Processing Systems
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• v.16 no.2
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• pp.261-276
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• 2020

Digital contents services are one of the topics that have been intensively studied in the media industry, where various semantic and ontology techniques are applied. However, query execution for ontology data is still inefficient, lack of sufficient extensible definitions for node relationships, and there is no specific semantic method fit for media data representation. In order to make the machine understand digital contents (DCs) data well, we analyze DCs data, including static data and dynamic data, and use ontology to specify and classify objects and the events of the particular objects. Then the formal representation method is proposed which not only redefines DCs data based on the technology of OWL/RDF, but is also combined with media segmentation methods. At the same time, to speed up the access mechanism of DCs data stored under the persistent database, an ontology-based DCs query solution is proposed, which uses the specified distance vector associated to a surveillance of semantic label (annotation) to detect and track a moving or static object.

• Biomolecules & Therapeutics
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• v.14 no.2
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• pp.75-82
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• 2006

Synaptic plasticity, which is a long lasting change in synaptic efficacy, underlies many neural processes like learning and memory. It has long been acknowledged that new protein synthesis is essential for both the expression of synaptic plasticity and memory formation and storage. Most of the research interests in this field have focused on the events regulating transcriptional activation of gene expression from the cell body and nucleus. Considering extremely differentiated structural feature of a neuron in CNS, a neuron should meet a formidable task to overcome spatial and temporal restraints to deliver newly synthesized proteins to specific activated synapses among thousands of others, which are sometimes several millimeters away from the cell body. Recent advances in synaptic neurobiology has found that almost all the machinery required for the new protein translation are localized inside or at least in the vicinity of postsynaptic compartments. These findings led to the hypothesis that dormant mRNAs are translationally activated locally at the activated synapse, which may enable rapid and delicate control of new protein synthesis at activated synapses. In this review, we will describe the mechanism of local translational control at activated synapses focusing on the role of cytoplasmic polyadenylation of dormant mRNAs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.327-328
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• 2006

Recently, as the infocomindustry is developed, the semiconductor industry as well as the optical industry such as the optical communication and the optical instrument is developed rapidly. The transmission, storage and processing of information has been reaching an limit because amounts of information increase rapidly. The more quickly the optical communication is developed, the more sharply the demand of optical elements increase. The transport and inspection process is time consuming and the error rate is high, because this process are not automated in case of an optical lens. In this paper, the pick-up system that can hold optical elements and be transferred by the ultrasonic transport system is developed. The inspection system that distinguishes between the existence and the nonexistence of a defect is connected easily to pick-up system. The pick-up system separates the optical glass lens by results of the inspection. The automation program is developed by visual c++ programming.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.184-191
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• 2005

The near-field scanning micro scope (NSOM) technique is in the spotlight as the next generation storage device. Many different types of read/write mechanism for NSOM have been introduced in the literature. In order for a near-field probe to be successfully implemented in the system, a suitable slider and suspension are needed to be properly designed. The optical slider is designed considering near-filed optics and probe array. The suspension generally supports slider performance, and tracking servo capacity in HDD. Moreover, the suspension for optical slider also should meet the optical characteristics, and is also required to satisfy shock performances for the mobility for the actuator. In this study, the optical slider and the suspension for near-field probe array are designed and analyzed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3312-3334
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• 2015

In this paper, a mechanism for spectrum allocation in overlay cognitive radio networks is proposed. In overlay cognitive radio networks, the secondary users (SUs) must first sense the activity of primary users (PUs) to identify unoccupied spectrum bands. Based on their different contributions for the spectrum sensing, the SUs get payoffs that are computed by the fusion center (FC). The unoccupied bands will be auctioned and SUs are asked to bid using payoffs they earned or saved. Coalitions are allowed to form among SUs because each SU may only need a portion of the bands. We formulate the coalition forming process as a coalition forming game and analyze it by game theory. In the coalition formation game, debtor-creditor relationship may occur among the SUs because of their limited payoff storage. A debtor asks a creditor for payoff help, and in return provides the creditor with a portion of transmission time to relay data for the creditor. The negotiations between debtors and creditors can be modeled as a Bayesian game because they lack complete information of each other, and the equilibria of the game is investigated. Theoretical analysis and numerical results show that the proposed auction yields data rate improvement and certain fairness among all SUs.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.360-367
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• 2003

Diamond-like carbon(DLC) films are considerable research interest because of their widespread applications as protective coatings in areas such as optical windows, magnetic storage disks, car parts, biomedical coatings and as micro-electromechanical devices(MEMs). DLC films were deposited on WC-Co by PECVD using Ar, $C_2H_4$ gas. Tribological tests were conducted using a ball-on-disk type tribometer in dry air. Three kinds of counter-bodies balls were used. The counter-bodies balls are SM45C, SUJ2 and $ZrO_2$(3.17mm in diameter). Wear rate of the samples were calculated after measuring the worn-out volume of the wear track. As results wear test, the higher hardness of counter-bodies, friction coefficient low. As result of XPS estimation, wear debris generated as an oxide lower the friction coefficient.