• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1361-1365
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• 2013

The smallest ketenimine and hydrogen cyanide N-methylide ($CH_2CNH$ and $CH_2NCH$) are provided from the argon/acetonitrile matrix samples exposed to radiation from laser ablation of transition-metals. New infrared bands are observed in addition to better determination of the vibrational characteristics for the previously reported bands, and the $^{13}C$ substituted isotopomers ($^{13}{CH_2}^{13}CNH$ and $^{13}CH_2N^{13}CH$) are also generated. Density functional frequency calculations and the D and $^{13}C$ isotopic shifts substantiate the vibrational assignments. $CH_2CNH$ is probably produced through single-step conversion of $CH_3CN$, whereas $CH_2NCH$ through two-step conversion via 2H-azirine. Inter-conversions between these two products evidently do not occur during photolysis and annealing.

• Macromolecular Research
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• v.12 no.1
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• pp.63-70
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• 2004

We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by the nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt; PN (Pluronic) was also used in place of PEG. All the bromo-terminated PEGs and PN were obtained in high yield. Conversions of the terminal hydroxyl groups to bromo-termini were quantitative, as were the drug conjugation processes. The Ι$_1$/Ι$_3$values obtained from solutions of the ibuprofen-conjugated prodrugs are summarized in relation to those of ibuprofen in water and in aqueous solutions of the original PEG, PN, and several ordinary surfactants. We believe that the fully hydrophilic PEG is completely hydrated and forms no hydrophobic pocket by segment aggregation. These results indicate that the probe environment is significantly hydrophobic, particularly in the solution of prodrug PN, for which the ratio is similar to that obtained from typical micelles of surfactants. The results suggest, therefore, that the present synthetic method is very useful for preparing PEG-based prodrugs from pharmaceuticals having carboxyl functionalities.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.51-59
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• 1999

As important ecological systems, wetlands contribute a wide array of biological, social. and economic benefits. However, wetlands are lost until the present, primarily due to human induced land-use conversions. Society is placing demands for the efficient preservation and management on Woopo wetland as the first largest wetland in Korea. GIS(Geographic Information System) is a rapidly developing technology for handling, analyzing, and modeling ecological information on wetlands. In the paper, Woopo Wetland Management System has been developed by using Desktop GIS and Internet GIS technology to embrace major functions: information query and browsing, spatial searching on map, and rule-based analysis. As a menu-driven system, these functions are designed to be implemented through customized menus. The developed system is expected to be used for the effective publicity service as well as the professional management of Woopo.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.33-36
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• 2003

This research was aimed at developing new catalytic membrane reactors to be used for : i) partial oxidation of toluene (to benzaldehyde and benzoic acid) ii) oxidative dehydrogenation of propane iii) complete oxidation of propane and toluene. The reactor is particularly useful for the optimisation and the industrial development of heterogeneous catalytic processes, particularly for those processes where it is necessary to control the reactants stoichiometry in the reaction zone. This control limits consecutive reactions, thus obtaining high selectivity with industrially interesting conversions. This presentation will concentrate on the partial oxidation of toluene.

• Journal of the Korea Computer Graphics Society
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• v.3 no.2
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• pp.77-84
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• 1997

Solid modeling refers to techniques for unambiguous representations of three- dimensional objects. The most widely used techniques for solid modeling have been Constructive Solid Geometry (CSG) and Boundary Representation (BRep). Contemporary solid modeling systems typically support both representations, and bilateral conversions between CSG and BRep are essential. However, computing a CSG from a BRep is largely an open problem. This paper presents 3D geometric reasoning algorithms for converting a BRep into a special CSG, called Destructive Solid Geometry (DSG) whose Boolean operations are all subtractions. The major application area of BRep-to-DSG conversion is feature recognition, which is essential for integrating CAD and CAM.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.613-625
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• 1998

This paper addresses a fundamental and theoretical model for the shape of a cucumber and its human-oriented proper definition of length and curvature in order to sort cucumbers electronically. In addition, we design a T-shaped array of sensors to minimize the number of sensors and the processing number of A/D(Analog/Digital) conversions, and we analyze regular patterns of a series of 1's and 0's which are converted from an A/D module. Finally we suggest an algorithm for measuring the length and curvature providing a rule from the regular patterns. The methodology suggested in this paper could be applied to electronical classification of some crops and fruits such as tomatoes, apples, and so on, and can be a basis for developing other sorting machines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.1
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• pp.79-85
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• 1998

The 9-digit MMSI(Maritime Mobile Service Identity) in the NBDP is converted to the 7-digit identity signal, used to identify to the phase of and to synchronize to the clock of the ISS(Information Sending Station) automatically for phasing procedure between radio stations. In this paper, algorithms for the automatic identification phasing procedures and for conversions, calculations between 7-signals and 9-identity, those check-numbers in the phasing procedures for calling of the NBDP are discussed and designed. And a method of the faster locking and phasing for calling than that of recommended by ITU-R is suggested and implemented.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1694-1703
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• 2014

Lightning induced voltage is a major factor that causes interruptions on distribution lines. In this paper, analytical expressions are proposed to evaluate a lightning induced voltage on power lines directly in the time domain without the need to apply any extra conversions. The proposed expressions can consider the widely used current functions and models in contrast to the earlier analytical expressions which had a number of limitations related to the simplification of the channel base current and the current along the lightning channel. The results show that the simulated values based on the proposed method are in good agreement with the previous studies and the proposed expressions can be used for optimizing the insulation and protection level of existing and new lines being designed.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.704-711
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• 2013

Data center is an information hub and resource for information-centric society. Since data center houses hundreds to ten thousands servers, networking and communication equipment, and supporting systems energy saving is one of the hottest issues for green data center. Among several solutions for green data center this paper introduces higher voltage direct current (DC) power feeding system. Contrary to legacy alternating current (AC) power feeding system equipped with Uninterruptible Power Supply (UPS), higher voltage DC power feeding system is reported to be a more energy efficient and reliable solution for green data center thanks to less AC/DC and DC/AC conversions. Main focus of this paper is on reliability issue for reliable and continuous operation of higher voltage DC power feeding system. We present different types of configuration of the power feeding systems according to the level of reliability. We analyze the reliability of the power feeding systems based on M/M/1/N+1/N+1 queueing model. Operation of the power feeding system in case of failure is also presented.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.319-320
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• 2015

A hybrid converter for the on-board charger consisting of a soft switching full bridge (SSFB) and a half bridge (HB) LLC resonant converter is proposed. The proposed topology adopts an additional switch and a diode at the secondary side of SSFB converter to guarantee the wide ZVS range of primary side switches and to eliminate the circulating current. The output voltage is regulated by controlling the duty cycle of secondary side switch. The effectiveness of the proposed converter was experimentally verified using a 10-kW prototype circuit. The experimental results show 96.8% peak efficiency.