• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.837-845
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• 2002

Based on ab initio calculations at the MP2(FULL)/6-31+G**//RHF/6-31G** level, we compare the energetic and mechanistic features of a model reaction for catalytic action of Δ?-3-ketosteroid isomerase (KSL,E.C.5.3,3.1) with those of a corresponding nonenzymatic reaction in aqueous solution. The results show that the two catalytic acid residues,Tyr14 and Asp99, can lower the free energy of activation by 8.6kcal/mol, which is in good agreement with the experimentally predicted~9 kcal/mol,contribution of electrophilic catalyses to the whole enzymatic rate enhancement. The dienolate intermediate formed by proton transfer from the substrate carbon acid to the catalytic base residue (Asp38) ins predicted to be stabilized by 12.0 kcal/mol in the enzymatic reaction, making its formation thermodynamically favorable. It has been argued that enzymes catalyzing the reactions of carbon acids should resolve the thermodynamic problem of stabilizing the enolate intermediate as well as the kinetic porblem of lowering the free energy of activation for porton abstraction. We find that KSI can successfully overcome the thermodynamic difficulty ingerent in the nonenzymatic reaction through the electrophilic catalyses of the two acid residues. Owing to the stabilization of dienolate intermediate, the reketonization step could influence the overall reaction rate more significantly in the KSI- catalyzed reaction than in the nonenzymatic reaction, further supporting the previous experimental findings. However, the electrophilic catalyses alone cannot account for the whole catalygic capability (12-13 kcal/mol), confiming the earlier experimental implications for the invement of additional catalytic components. The present computational study indicates clearly how catalytic residues of KSI resolve the fundamental problems associated with the entropic penalty for forming the rate-limiting transition state and its destabilization in the bulk solvation environment.

• Journal of Korea Technology Innovation Society
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• v.13 no.2
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• pp.282-309
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• 2010

Recently, technology acquisition through technology trade plays a critical role in obtaining national competitiveness in a global era. However, current studies mostly focus on grasping the characteristics or macro status of technology trade and analyzing the impact of technology acquisition through the technology transaction, leading to the failure of providing a theoretical and practical background of national policy-making. Therefore, this research aims at investigating the concentration rate of technology, companies and countries where Korean companies obtain technological capability on the basis of the Bank of Korea's data related to 'loyalty payment in technology licensing', additionally analyzing the types of exported technology and loyalty payment. From these analyses, the degree of concentration that pre-defined 31 technology classifications depend on specific technologies, companies and nations are examined and the characteristics of technology trade types are investigated. The results of this research can be used to make a technology policy and analyze the characteristics of technology innovation of Korea industries.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1993-2005
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• 2016

Bacillus pumilus is one of the most characterized microorganisms that are used for high-level production of select industrial enzymes. A novel B. pumilus SCU11 strain possessing high alkaline protease activity was obtained in our previous work. The culture supernatant of this strain showed efficient dehairing capability with minimal collagen damage, indicating promising potential applications in the leather industry. In this study, the strain's extracellular proteome was identified by LC-MS/MS-based shotgun proteomic analysis, and their related secretory pathways were characterized by BLAST searches. A total of 513 proteins, including 100 actual secreted and 413 intracellular proteins, were detected in the extracellular proteome. The functions of these secreted proteins were elucidated and four complete secretory systems (Sec, Tat, Com, and ABC transporter) were proposed for B. pumilus. These data provide B. pumilus a comprehensive extracellular proteome profile, which is a valuable theoretical and applicative basis for future genetic modifications and development of industrial enzymes.

• The Journal of Korean Association of Computer Education
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• v.7 no.4
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• pp.103-110
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• 2004

As the importance of learner-centered ICT education is emphasized, school education should move toward the direction of respecting individual learners' capability rather than fitting learners into a fixed frame. Such a view finds its theoretical ground in Gardner's multiple intelligences theory. Thus ICT literacy education in elementary school also needs to consider individual student's abilities and talents based on their multiple intelligences and apply appropriate education programs and teaching methods. In order to provide basic materials for this, the present study examined the correlation between children's academic achievement in ICT literacy education and their multiple intelligences and inquired into which intelligences are factors determining achievement in ICT literacy education. According to the results. logical-mathematical intelligence is in a significant correlation with academic achievement in ICT literacy education. and logical-mathematical intelligence and linguistic intelligence are the most influential factors on academic achievement in ICT literacy education.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.47-53
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• 2007

The safe operation of high pressure pipe line systems is of significant importance. Leaks due to faulty operation from the pipelines can lead to considerable product losses and to exposure of community to dangerous gases. There are several leak detection methods, which have been recently suggested on pipeline network. The negative pressure wave detection technology, which has advantages of short time detection availability, accurate leaking location estimate capability and cost effective, is concentrated in this study. Theoretical analysis of the flow characteristics for leaking through a hole on the pipe wall has been performed by using CFD++, commercial CFD package. The results of 3-dimensional analysis near leaking hole confirm the occurrence of negative pressure wave and verify the characteristics of propagation of the wave which travels with speed equal to the speed of sound in the pipeline contents. For the application of long pipe line system. The method of 1-dimensional analysis has been suggested and verified with results of CFD++.

• Journal of Communications and Networks
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• v.14 no.2
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• pp.162-168
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• 2012

This paper considers the scenario in which a set of nodes share a common channel. Some nodes have a rechargeable battery and the others are plugged to a reliable power supply and, thus, have no energy limitations. We consider two source-destination pairs and apply the concept of cognitive radio communication in sharing the common channel. Specifically, we give high-priority to the energy-constrained source-destination pair, i.e., primary pair, and low-priority to the pair which is free from such constraint, i.e., secondary pair. In contrast to the traditional notion of cognitive radio, in which the secondary transmitter is required to relinquish the channel as soon as the primary is detected, the secondary transmitter not only utilizes the idle slots of primary pair but also transmits along with the primary transmitter with probability p. This is possible because we consider the general multi-packet reception model. Given the requirement on the primary pair's throughput, the probability p is chosen to maximize the secondary pair's throughput. To this end, we obtain two-dimensional maximum stable throughput region which describes the theoretical limit on rates that we can push into the network while maintaining the queues in the network to be stable. The result is obtained for both cases in which the capacity of the battery at the primary node is infinite and also finite.

• The Research Journal of the Costume Culture
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• v.19 no.1
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• pp.230-243
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• 2011

In this modern digital era, there are very vigorous arguments about digital and media aesthetics throughout culture and art on the basis of new transferring of recognition about the art-media's characteristics. Therefore, this paper tries to discover the art-media's characteristics and aesthetic value that are included in contemporary digital fashion through studying the fusion between digital and fashion. The purpose of this research is to offer positive and evolutive opportunity of artistic thinking to make the meeting between fashion and media suggest the future generation, adaptation and recognition in the media - developmental environment that will be deeper and more fueling. In the area of research method, this paper takes the method of theoretical research by referring national and foreign literatures and preceding research-papers, and carries out investigation and analysis about digital fashion for the last 10 years. The results of this study; The art-media's characteristics of modern digital fashion are virtuality, immateriality and characteristics of multimedia. The aesthetic values can be classified with four kinds of properties. First is hybridity initiated from multi-media that creates works; the second is infinite reproductivity initiated from the characteristics of the multi media and the digital carrier. Thirdly, there is also interactivity appeared all over the area of production, adaptation and perception caused by non-linearity and immateriality. Finally there is synesthesia that can extend the capability of sense through digital media.

• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.55-60
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• 2001

Objectives : The SERVQUAL scale is based on gap theory, which suggests the difference between consumers' expectations and the quality of the medical service actually received. However, problems in the implementation of the SERVQUAL scale have been identified by several researchers. Some researchers have proposed a simple performance-based measure (SERVPERF) or au exportation-controlled performance-based measure(Non-Diff) as alternatives to the SERVQUAL scale. On the basis of the theoretical concerns discussed, we examined the capability of each of the three scales(SERVQUAL, Non-Diff, SERVPERF) to explain variations in consumer satisfaction. Methods : Data was gathered from a self-administered questionnaire in a 430 bed hospital. Questionnaires evaluating medical services were distributed to 180 ambulatory patients. A total of 167 usable questionnaires were gathered. The questionnaire was composed of 10 expectation, performance and expectation-controlled performance items. In addition, overall satisfaction and purchase intention were measured. Results : Compared with the SERVQUAL scale, the Non-Diff and SERVPERF scales better explained the observed variations in consumer satisfaction(SERVOQUAL, $R^2=0.29;\;Non-Diff,\;R^2=0.51;\;SERVPERF,\;R^2=0.48$) and purchase intention(SERVQUAL, $R^2=0.22;\;Non-Diff,\;R^2=0.33;\;SERVPERF,\;R^2=0.34$). Conclusion : The maier conclusion from our study is that the Non-Diff and SERVPERF scales are more efficient in assessing consumer satisfaction than the SERVQUAL scale. Therefore we suggest that consumer satisfaction he measured by the Non-Diff or SEVPERF scales.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3C
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• pp.314-319
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• 2010

The chirp spread spectrum (CSS) technique that spreads the data signal over a wider frequency band via chirp signal for transmission has attracted much attention in the field of wireless communications due to capability to resist multipath fading signals. However, there has been little mathematical analysis for the performance of CSS-based communication systems in the multipath fading environments. In this paper, we study the influence of the multipath channel on the direct modulation (DM) scheme with M-ary phase shift keying (MPSK). When a chirp signal is transmitted on the Rayleigh fading channel and affected by additive white Gaussian noise (AWGN), we derive the theoretical performance. From numerical results, it is confirmed that the analytic symbol error rate (SER) agrees closely with the empirical SER.

• Journal of KIISE:Databases
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• v.32 no.6
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• pp.603-615
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• 2005

As recent business environments are changed and become complex, a more efficient and effective business process management are needed. This paper proposes a new approach to the automatic execution of business processes using Event-Condition-Action (ECA) rules that can be automatically triggered by an active database. First of all, we propose the concept of blocks that can classify process flows into several patterns. A block is a minimal unit that can specify the behaviors represented in a process model. An algorithm is developed to detect blocks from a process definition network and transform it into a hierarchical tree model. The behaviors in each block type are modeled using ACTA formalism. This provides a theoretical basis from which ECA rules are identified. The proposed ECA rule-based approach shows that it is possible to execute the workflow using the active capability of database without users' intervention.