• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.111-120
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• 2010

Looking at the application examples related to RFID systems around the world, it is easy to find that RFID systems are introduced in various industries, such as retail and consumer goods sectors, financial and security sectors, automotive and transport sector, leisure and sports sector, logistics, and health-related fields. This is because they can get their operational efficiency and competitiveness by means of product's visibility and transparency of information through RFID systems. However, it is required that evaluation of effectiveness on introducing RFID systems should be performed to strengthen construction willingness of RFID systems before actual introduction of the RFID systems in the process. This activity affects to introduction of RFID systems in industry-wide and then, will be able to create a synergy effect such as national industrial competitiveness improvement. The purpose of this study is to offer rational method on effectiveness analysis before and after RFID based process. Accordingly, the proposed Choquet fuzzy integral-based model will be allowed rational analysis by integrating quantitative and qualitative analysis. Through the effectiveness analysis of C company's RFID based process using the proposed evaluation model, we could identify that RFID-based logistics process was more effective than existing process.

• KSBB Journal
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• v.27 no.1
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• pp.1-8
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• 2012

Recently, translational research (TR) in health technology (HT) has been considered as an emerging alternative research system for the improvement of human health. TR from bench to bedside involves a strong bidirectional relationship between basic science discovery and clinical practice. To support R&D planning and policy in HT effectively, the performance of TR programs was analyzed and evaluated in a R&D project on health and medical technology. TR programs were classified into three parts: unilateral TR, bilateral TR and multilateral TR. Bibliometrics and citation analysis were performed to assess research papers and gather information for the performance analysis of TR programs. In addition, both quantitative and qualitative analysis were successfully carried out using ISI Web of Science, Google Scholar Citations, SCOPUS and Knowledgematrix. In conclusion, the performance analysis of TR programs could significantly improve the efficiency of R&D plans, R&D management and evaluation for a safe and healthy life.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.282-291
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• 2011

Adaptive modulation(AM) is an important technique to increase the system efficiency, in which transmitter selects the most suitable modulation mode adaptively according to channel state in the temporary and spatially varying communication environment. Fixed modulation on channels with varying signal-to-noise ratio(SNR) is that the bit-errorrate(BER) probability performance is changing with the channel quality. An adaptive modulation scheme can be designed to have a BER which is constant for all channel SNRs. The correct as well as fast and simple SNR estimation is required essentially for this adaptive modulation. In order to operate adaptive modulation system effectively, in this paper, we analyze the effect of SNR estimation performance to it through the average BER and data throughput. Applying SNR estimation based on auto-correlation of decision feedback signal and others to adaptive modulation system, we also confirm performance degradation or improvement of its which is decided by SNR estimation error at each transition point of modulation level. Since SNR estimation based on auto-correlation of decision feedback signal shows stable estimation performance for various quadrature amplitude modulation(QAM) comparatively, this can be reduced degradation than others at each transition point of modulation level.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.334-342
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• 2018

Purpose: The purpose of this study is to examine and improve the issues related to National Safety Inspection currently operation and reform the system for response to various disasters. Method: For the completion, this study established theoretical background using materials related to National Safety Inspection and identified the issues using the open statistical data for National Safety Inspection to suggest the improvement plans. Results: National Safety Inspection has been operating a complete large-scale inspection on risk factors in cooperation with the central government, local governments, and citizens since 2015 to remove various disaster factors neglected in people's daily lives. Operation of National Safety Inspection had positive influence in preventing major disasters. However, inefficient activity is pointed out due to issues related to cooperation with other institutes, limitation for citizen's positional role, and superficial inspection. Conclution: To solve this issue, this study proposed strengthening of communication activity with disaster institutes, strengthening of efficiency through citizen participation by type, and actualization of checklist used in National Safety Inspection.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.438-447
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• 2004

A new multilevel PWM inverter using a half-bridge and full-bridge cells is proposed for the use of stand-alone photovoltaic inverters. The configuration of the proposed multilevel PWM inverter is based on a prior 11-level shaped PWM inverter. Among three full-bridge cells employed in the prior inverter, one cell is substituted by a half-bridge cell. Owing to this simple alteration, the proposed inverter has three promising merits. First it increases the number of output voltage levels resulted in high quality output voltages. Second, it reduces two power switching devices by means of employing a half-bridge cell. Third, it reduces power imposed on a transformer connected with the half-bridge unit. That is to say, most power is transferred to loads via cascaded transformers connected with low switching inverters, which are used to synthesize the fundamental output voltage levels whereas the output of a transformer linked to a high switching inverter is used to improve the final output voltage waves; thus, it is desirable in the point of the improvement of the system efficiency. By comparing to the prior 11-level PWM inverter, it assesses the performance of the proposed inverter as a stand-alone photovoltaic inverter. The validity of the proposed inverter is verified by computer-aided simulations and experimental results.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.110-116
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• 2001

This experiment was carried out to investigate the effects of amount of nitrogen application with the barley straw application on the changes in soil physical and chemical properties. nutrient uptake and percentage recovery of chemical fertilizer N in the rice plant from 1997 to 1998. The soil physical properties, such as bulk density, hardness, porosity and gaseous phase were improved by barley straw application. There was also improvement or increment in the soil chemical properties, such as pH, organic matter, T-C. T-N, available $SiO_2$, exchangeable K and cation exchange capacity, but decrease in available $P_2O_5$. The $Fe^{+{+}}$ content in soil after barley straw application was high from tillering stage to panicle forming stage, but becoming lowered toward the heading stage, while $Mn^{+{+}}$ content was increased. N uptake with barley straw application was increased in the N $126kg\;ha^{-1}$ plot, but decreased in the N $141kg\;ha^{-1}$ plot. The uptake of fertilized N was continued longer in barley straw application than none-application plot. Percentage recovery of chemical fertilizer N in rice straw was around 1% at tillering stage, but was highly increasing till maximum tillering stage, while the recovery was generally low in barley straw application. Meanwhile, fertilizer P uptake in barley straw application was high, but potassium uptake was low at all different levels of N application.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.115-119
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• 2010

As the subjects of education has been changed from the instructors to learners, a web-based self-directed learning which can accelerate the initiative of learners and can be free from the restriction of time and space has been received attention. In this paper, the web-based self-directed learning system was designed. For the design, to make the learners build their own lecture plan, the service was designed to provide three kinds of lectures of video clip, slide lecture, and e-text lecture that were focused on various lecture contents. In addition, a learner and an assistant was man to man matched to enable the on-line mentoring for mutual communication between learners and assistants. Implementation was carried out by three sets of module - Manager, Learner and Assistant - that were applied to the real educational activities. The survey on satisfaction for the education, efficiency of ability improvement, and educational intelligibility for the attendants on the education showed more than 67.2% of satisfaction in satisfaction for the education. Furthermore, more than 86.9% of attendants replied that their ability were improved after the education of this system. The educational system realized in this paper shows effectiveness for the self-directed learning.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.1-6
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• 2008

This study investigated the changes of indoor thermal environment by Ardisia species planted in indoor space. Three Ardisia species (Ardisia japonica, Ardisia crenata and Ardisia pusilla) were used in this study and differences of temperature and relative humidity were ascertained in an empty chamber with and without plants. In high temperatures over $24^{\circ}C$, Ardisia species cooled down chamber more as compared to the control without plants, but there were no significant differences among Ardisia species. Ardisia crenata showed high relative humidity of $57.3{\pm}3.1%$ during most of the day time and $60.8{\pm}2.5%$ at low temperatures. However, Ardisia japonica and Ardisia pusilla showed $54.7{\pm}1.18%$ and $52.5{\pm}2.4%$, respectively, on the average, and they maintained comfortable relative humidity during most of the day time. When the setting temperature was decreased from 28 to $26^{\circ}C$, Ardisia species showed 7.5~13.6 times greater cooling efficiency as compared to the control without plants, and at low temperatures the chamber without plants showed higher themal energy than the chamber with plants. Ardisia species were effective on cooling down the temperature at high temperatures and they showed a tendency to maintain proper temperatures at low temperatures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.310-316
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• 2019

In automotive application, customers are demanding high efficiency and various functions for convenience. The demand for these automotive applications is steadily increasing. In this study, it has been studied the analysis of heat flow to improve the PCB(printed circuit board) heating performance of WPC (wireless power charger) recently developed for convenience. The charging performance of the wireless charger has been reduced due to power dissipation and thermal resistance of PCB. Therefore, it has been proposed optimal PCB design, layout and position of electronic parts through the simulation of heat flow analysis and PCB design was analyzed and decided at each design stage. Then, the experimental test is performed to verify the consistency of the analysis results under actual environmental conditions. In this paper, The PCB modeling and heat flow simulation in transient response were performed using HyperLynx Thermal and FloTHERM. In addition, the measurement was performed using infrared thermal imaging camera and used to verify the analysis results. In the final comparison, the error between analysis and experiment was found to be less than 10 % and the heating performance of PCB was also improved.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.773-782
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• 2009

A DHT(Distributed Hash Table) based P2P is a method to overcome disadvantages of the existing unstructured P2P method. If a DHT algorithm is used, it can do a fast data search and maintain search efficiency independent of the number of peer. The peers in the DHT method send messages periodically to keep the routing table updated. In a mobile environment, the peers in the DHT method should send messages more frequently to keep the routing table updated and reduce the failure of a request. Therefore, this results in increase of network traffic. In our previous research, we proposed a method to reduce the update load of the routing table in the existing Chord by updating it in a reactive way, but the reactive method had a disadvantage to generate more traffic than the existing Chord if the number of requests per second becomes large. In this paper, we propose an adaptive method of routing table update to reduce the network traffic. In the proposed method, we apply different routing table update method according to the number of request message per second. If the number of request message per second is smaller than some threshold, we apply the reactive method. Otherwsie, we apply the existing Chord method. We perform experiments using Chord simulator (I3) made by UC Berkeley. The experimental results show the performance improvement of the proposed method compared to the existing methods.