• Knowledge Management Research
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• v.5 no.2
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• pp.25-51
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• 2004

The purpose of this study is to investigate the knowledge creating pattern of technology catching-up and pioneering phase in the new product development process. This paper first reviews the knowledge conversion, absorptive capability, learning orientation and the trigger of learning. The paper then presents the integrative model of knowledge creating. Based on the integrative model, in-depth case analysis was conducted on the new product development process in Phicom. As a result, the paper discuss that the pattern of absorptive capability building, knowledge conversion and knowledge transfer is different from technology catching-up and pioneering phase. Finally, the implications and limitations of the study are discussed.

• Journal of Photoscience
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• v.11 no.1
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• pp.1-6
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• 2004

Molecular assembling is one of the current interests in the field of bottom-up nanotechnology. Self-assembled monolayers of sulfur-containing molecules or supramolecular assemblies via surface sol-gel processes formed on conductive supports are chemically robust and can be easily fabricated without sophisticated instruments. We have fabricated various types of molecular assemblies consisting of donor-acceptor pairs on the surfaces of gold and indium-tin-oxide electrodes. Build-up of three-dimensional multi structures consisting of thiol dyes and gold nanoparticles also has been successful. These assemblies showed clear photocurrent responses in photoelectro-chemical cells. In this article, we will describe recent progress on photoelectric conversion using molecular assemblies especially focused on our research results.

• ETRI Journal
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• v.26 no.4
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• pp.344-350
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• 2004

We propose a filter-free wavelength conversion using a Mach-Zehnder interferometer with monolithically integrated $2{\times}2$ multimode interference semiconductor optical amplifiers (MMI-SOAs). The device has been optimized by considering a non-homogeneous carrier distribution due to the self-imaging properties of the MMI-SOA. Static measurements show an extinction ratio of up to 18 dB and an input signal rejection ratio of up to 20 dB.

• Journal of Power Electronics
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• v.11 no.5
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• pp.669-676
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• 2011

A novel polarity inversion dc-dc power conversion circuit that features the high input to output step-up voltage conversion ratio characteristics is presented for high voltage DC power supply applications. The proposed circuit features the reduced voltage stresses of the components compared to those of the conventional ones. The operational principles of the proposed circuit are analyzed and comparative features are presented. The simulation results and experimental results are presented to verify the validity of the proposed circuit.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.61-64
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• 2000

This paper describes a RF Down-Conversion Mixer for mobile communication systems. This circuit achieves low voltage operation and low power consumption by reducing stacked devices of conventional gilbert cell mixer. In order to reduce stacked devices, we use source-follower structure. The proposed RF Down-Conversion mixer operates up to 1.85GHz at 1.5V power supply with 0.25um CMOS technology and consumes 2.2mA.

• Journal of Korean Biological Nursing Science
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• v.11 no.2
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• pp.120-127
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• 2009

Purpose: The study aimed at monitoring the immune status of health care workers (HCWs) of a tertiary hospital after accidental exposure to Hepatitis B virus (HBV). Methods: Between January 2004 and December 2006, 353 cases of exposure to Hepatitis B virus were reported. The HBV-exposed HCWs were required to undergo follow-up serum tests to analyze their immune status one year after the exposure. The obtained data were then analyzed to determine the incidence of exposure and of sero-conversion. Results: In this hospital, an average of 9.8 cases of Hepatitis B exposure among HCWs was reported in a month. Follow-up tests conducted after exposure revealed that 90.4% of the HBV-exposed HCWs were positive for Hepatitis B antibody and 66.9% of the HBV-exposed HCWs were reported to have antibody levels exceeding 10 mIU/mL. Results of serum tests for the HBV antigen conducted one year after exposure were negative for all the exposed HCWs. Conclusion: Among the 79.6% of the HCWs who underwent serum tests one year after exposure the HBV sero-conversion rate was 0.0%. However, a further investigation in the form of long-term and multi-center studies is required to confirm this result. Furthermore, an active system should be established to ensure that all exposed HCWs undergo follow-up serum tests.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.201-206
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• 2011

FRUC (Frame Rate Up-Conversion) technique needs an effective frame interpolation algorithm using motion information between adjacent neighboring frames. In order to have good visual qualities in the interpolated frames, it is necessary to develop an effective detection and interpolation algorithms for occluded regions. For this aim, this paper proposes an effective occluded region detection algorithm through the adaptive forward and backward motion searches and also by introducing the minimum value of normalized cross-correlation coefficient (NCCC). That is, the proposed scheme looks for the location with the minimum sum of absolute differences (SAD) and this value is compared to that of the location with the maximum value of NCCC based on the statistics of those relations. And, these results are compared with the size of motion vector and then the proposed algorithm decides whether the given block is the occluded region or not. Furthermore, once the occluded regions are classified, then this paper proposes an adaptive interpolation algorithm for occluded regions, which still exist in the merged frame, by using the neighboring pixel information and the available data in the occluded block. Computer simulations show that the proposed algorithm can effectively classify the occluded region, compared to the conventional SAD-based method and the performance of the proposed interpolation algorithm has better PSNR than the conventional algorithms.

• Journal of Broadcast Engineering
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• v.20 no.6
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• pp.880-887
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• 2015

In this paper, frame rate up conversion (FRUC) algorithm considering the direction and magnitude of identical motion vectors is proposed. extended bilateral motion estimation (EBME) has higher complexity than bilateral motion estimation (BME). By using average magnitude of motion vector with x and y direction respectively, dynamic frame and static frame are decided. We reduce complexity to decide EBME. also, After we compare the direction and magnitude of identical motion vectors, We reduce complexity to decide motion vector smoothing(MVS). Experimental results show that this proposed algorithm has fast computation and better peak singnal to noise ratio(PSNR) results compared with EBME.

• Journal of the Korean Regional Science Association
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• v.11 no.1
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• pp.61-78
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• 1995

This study begins with a question of what spatial impact international trade policy would have following the Uruguay Round, particularly focusing on agricultural trade liberalization in Korea. Based upon the neoclassical urban economic model, it first identifies the channel in which agricultural market opening can ultimately affect both rural and urban are as; $\circled1$ Free trade will depress domestic price of agricultural products, $\circled2$ which will in turn depreciate agricultural land price. $\circled3$ The decrease in marginal supply cost for urban land will then facilitate urban sprawl, provided that the government relaxes restrictions on urban-rural land conversion. Theoretical analysis is further refined by empirical considerations that distinguish agricultural land value solely for production purpose from that for future urban, uses, and that distinguish the urbanization effect caused by the fall in the supply cost of urban land from that caused by the existing high level of demand. Utilizing the estimate of bid-price for paddy field derived from the revenue-cost relationship of rice production, simulation results show that the urban-rural boundary under trade liberalization can expand outward up to 70-85km radius in the Seoul metropolitan area, suggesting the emergency of a metropolis or even a megalopolis which extends from Seoul to the central part of the country. Since the geographic extent of urbanization effect can vary depending upon the urban spatial structure, however, it is recommended that the redevelopment option in the built - up area should always be tied up with the issue of whether to deregulate rural-to-urban land conversion.

• Journal of Hydrogen and New Energy
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• v.22 no.4
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• pp.465-473
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• 2011

To find the optimum mixing ratio of WGS catalyst with $CO_2$ absorbent for SEWGS process, water gas shift reaction tests were carried out in a fluidized bed reactor using commercial WGS catalyst and sand (as a substitute for $CO_2$ absorbent). WGS catalyst content, gas velocity, and steam/CO ratio were considered as experimental variables. CO conversion increased as the catalyst content increased during water gas shift reaction. Variations of the CO conversion with the catalyst content were small at low gas velocity. However, those variations increased at higher gas velocity. Within experimental range of this study, the optimum operating condition(steam/CO ratio=3, gas velocity = 0.03 m/s, catalyst content=10 wt.%) to get high CO conversion and $CO_2$ capture efficiency was confirmed. Moreover, long time water gas shift reaction tests up to 20 hours were carried out for two cases (catalyst content = 10 and 20 wt.%) and we could conclude that the WGS reactivity at those conditions was maintained up to 20 hours.