• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.35-43
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• 2007

In this paper, the inductive power collector using electromagnetic induction for vehicle such as the PRT(Personal Rapid Transit) system is suggested and son ideas for power collector design to improve tile power transfer performance are presented. And also, the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency is shown. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system electrical power is transferred from a primary winding in the form of a coil or tract to one or more isolated pick-up coils that my relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, we will show you various characteristic of inductive power transfer system as double layer construction of secondary winding, which was divided in half to increase both output current and output voltage, a model of power collector and parallel winding structure, a model of concentration/ decentralization winding and the effects of parameter and operational frequency variation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2087-2102
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• 2011

The purpose of this study is to develop and present a strategic framework for mobile Internet marketing in the $Web^2$ environment. The $Web^2$ mobile Internet marketing is characterized by services, such as augmented reality and social network services. Considering the changes in the effects and types of advertisements in the mobile Internet, few studies of mobile advertisements have been conducted thus far in the $Web^2$ environment, including the cloud computing environment. Accordingly, this research aims to identify the relationships between importance and satisfaction and to uncover the characteristics of mobile advertisements through smart phones using the IPA (Importance-performance Analysis) methodology in the $Web^2$ environment. To induce the minimum required characteristics of a mobile advertisement in terms of the importance and satisfaction of IPA, Kano's model is applied to this analysis. The study also probes the relationships between the overall satisfaction and factors of each dimension of IPA through a regression analysis. As a result, this study presents four types of $Web^2$ mobile Internet marketing strategies. It was also confirmed that the maintenance reinforcement factors of the IPA dimension affect the degree of overall satisfaction. This study has implications for businesses and researchers preparing $Web^2$ mobile services and marketing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.96-116
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• 2016

Sensing coverage is a fundamental issue for Wireless Sensor Networks (WSNs). Several coverage configuration protocols have been developed; most of them presume the availability of precise knowledge about each node location via GPS receivers. However, equipping each sensor node with a GPS is very expensive in terms of both energy and cost. On the other hand, several GPS-less localization algorithms that aim at obtaining nodes locations with a low cost have been proposed. Although their deep correlation, sensing coverage and localization have long been treated separately. In this paper, we analyze, design and evaluate a novel integrated framework providing both localization and coverage guarantees for WSNs. We integrate the well-known Coverage Configuration Protocol CCP with an improved version of the localization algorithm AT-Dist. We enhanced the original specification of AT-Dist in order to guarantee the necessary localization accuracy required by CCP. In our proposed framework, a few number of nodes are assumed to know their exact positions and dynamically vary their transmission ranges. The remaining sensors positions are derived, as accurately as possible, using this little initial location information. All nodes positions (exact and derived) are then used as an input for the coverage module. Extensive simulation results show that, even with a very low anchor density, our proposal reaches the same performance and efficiency as the ideal CCP based on complete and precise knowledge of sensors coordinates.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.86-95
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• 2002

Anaerobic digestion of municipal solid waste(MSW) is recently getting attention due to energy generation and abatement of global warming. MSW has high solid content and low nitrogen content. Its major component is cellulose and hemicellulose. The conversion rate of organic portion of MSW to methane is approximately 50%, representing $0.2m^3/kg$ VS. Long hydraulic retention time is required for high solid content and inoculum should be mixed with the feed. When MSW is digested anaerobically, maximum limit of C/N ratio is 25 and the optimum concentration of $NH_3-N$ is 700mg/L. lime and sodium bicarbonate are used to adjust pH. Excess addition of sodium bicarbonate above 3,500mg/L will cause sodium toxicity. Thermophilic anaerobic digestion is effective in the control of pathogen although its operation and maintenance is difficult. To optimize the anaerobic digestion of MSW, it is necessary to understand the mechanism of microorganims involved in anaerobic digestion.

• Wind and Structures
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• v.20 no.6
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• pp.739-749
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• 2015

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

• Structural Monitoring and Maintenance
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• v.7 no.3
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• pp.215-231
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• 2020

In a reinforced concrete building different shapes of column are adopted depending on the structural orientation and the architectural aspect. When there is an increase in loading due to changes in usage or revision in the design codes these columns need to be strengthened for enhanced performance during their service life. Strengthening materials such as carbon fiber and glass fiber polymer has been successfully used however, due to high cost application other alternative materials need to be explore. Galvanized steel wire mesh (GSWM) is one of the suitable materials locally available. High tensile strength, low weight, corrosion resistance, easy installation, minimum change in dimensions of the sections and cost effectives are the advantages of GSWM. Therefore, in this paper, four different shapes of column such as circular, square, rectangular and L were wrapped with different layers GSWM and jacketed with mortar. All the specimens were tested under axial compression. The objective of the study is to investigate the effectiveness of GSWM as a confining material for strengthening of column having varying shape. Test results shows that the axial strength enhanced with wrapping of GSWM jacket and a circular column presented the highest load carrying capacity and ductility as compared to the others. From the study of 22 column specimens, it is found that axial load is increased upto 20% and 19% when circular and square column are strengthened with one wrap of GSWM respectively, while a rectangular and L column required a wraps of two and three layers respectively in order to achieved the same load capacity as that of a circular column. Based on the present study, it is concluded that GSWM can be effectively used for strengthening of different shapes of concrete columns economically.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.6
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• pp.194-206
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• 2003

A pilot study was performed to examine the feasibility of the pond system for further polishing of treatment wetland effluent to agricultural reuse of reclaimed water. The constructed wetland and pond system was installed in Konkuk University and the effluent from septic tank of school building was used as an influent to the wetland system. The effluent of the wetland was used as an influent to pond systems. The influent concentrations of total coliform(TC), fecal coliform (FC), and E. coli were about $10^5$MPN/100 ml, and they were reduced to less than 10,000 MPN/100 ml on average after wetland treatments, showing over 95 % removal. And they were further reduced to less than 1,000 MPN/100 ml in average, showing over 85∼93 % removal after pond treatment. Turbidity and SS were improved effectively on average and their pond effluent concentration was about 4.5 NTU and 9.8 mg/L in average, respectively Average $BOD^5$ concentrations were also reduced substantially to 9.3 mg/L with about 83 % removal rate after wetland and pond treatment systems. Nutrients removal was relatively low and removal rate for T-N and T-P was less than 43 and 44%, respectively after wetland and pond treatment. Considering stable performance and effective removal of bacterial indicators as well as other water quality parameters, low maintenance, and cost-effectiveness, pond system was thought to be an effective and feasible alternative for agricultural reuse of reclaimed water. This paper describes a preliminary result Iron pilot study and further investigations are recommended on the optimum design parameters before full scale application.

• Broadcasting and Media Magazine
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• v.15 no.1
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• pp.24-36
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• 2010

Nowadays, digital broadcasting providers have plan to extend their service area to 3D broadcasting without exchanging conventional system and equipments. The maintenance of backward compatibility to conventional 2D broadcasting system is very importance issue on digital broadcasting. To satisfy the requirement, highly-optimized MPEG-2 video encoder is essential for coding left-view and new video coding techniques having higher performance than MPEG-4 AVC/H.264 is needed for right-view since terrestrial broadcasting system has very limited and fixed bandwidth. In this paper, conventional video coding algorithms and new video coding algorithms are analyzed to present a capable solution for the best quality stereoscopic 3D broadcasting keeping backward compatibility within the bandwidth.

• Journal of KIISE:Databases
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• v.27 no.2
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• pp.175-184
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• 2000

A data warehouse is an integrated and summarized collection of data that can efficiently support decision making process. The summarized data at the data warehouse is often stored in materialized views. These materialized views need to be updated when source data change. Since the propagation of updates to the views may impose a significant overhead, it is very important to update the warehouse views efficiently. Though various strategies have been proposed to maintain views in the past, they typically require too much accesses to the data sources when the changes of multiple data sources have to be reflected in the view. In this paper we propose an efficient view update strategy that uses relatively small number of accesses to the data sources. We also show the performance advantage of our method over other existing methods through experiments using TPC-D data and queries.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.11-14
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• 2003

To evaluate the ewe reproductive performances of three Iranian local sheep breeds, namely Moghani, Chal and Zel, 27 rams and 473 ewes were used as the foundation flock in a crossbreeding program. The three breeds were crossed amongst themselves reciprocally. Ram breed and ewe breed showed a two-way interaction on apparent fertility. The Zel ewes showed higher fertility than the Chal and Moghani ewes (94.4 vs 77.3 and 84.6%). Prolificacy among main and individual mating groups were not significantly different (p>0.05). Zel ewes were 22.3 and 14.8% more reproductive (p<0.05) than Chal and Moghani ewes, respectively. Zel and Moghani ewes showed higher (p<0.05) ewe productivity than Chal ewes. Ram breed had a significant (p<0.05) effect on ewe efficiency. The Zel rams were not completely successful to mate with Chal ewes, this caused a to way-interaction between ram and ewe breeds. The Zel ewes mated with Chal and Moghani rams showed 26.1 and 28.5% more efficiency than those mated with Zel rams. This observation strongly supports the use of crossbreeding to improve the efficiency of the Zel ewes. With decreasing lamb mortality, through supplemented feeding of lambs in pre-weaning period, and increasing litter weight, through crossbreeding, it should be possible to improve the efficiency of Zel ewes even better than Chal and Moghani ewes. Small body size of Zel ewes that needs the lower maintenance requirements would be a well advantageous to using Zel ewes as the dam herd to produce commercial lambs in north area of Iran.