• Journal of Broadcast Engineering
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• v.4 no.2
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• pp.164-175
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• 1999

Based on the performance analyses for transmission channel and signal characteristics in digital satellite broadcasting system. the optimal design parameter values for system using QPSK modulation technique were proposed in this paper. The proper performance degradation were of 2.0dB for channel characteristics. O.4dB for transmission signal characteristics and 0.2dB for receiver characteristics. respectively. In this case. the design objectives for system parameters were within ${\pm}\;0.5dB$ for gain flatness in 27MHz bandwidth. and O.1nsec/MHz and $0.2sec/MHz^2$ for linear and parabolic group delay. respectively. Also. the optimal parameter values that provide the maximum availability were of OdB OBO for satellite transponder TWTA. and the optimal bandwidth for PLL circuit was of 40kHz with 0.707 damping factor. These analyses and design values can be available for high data rate transmission system via satellite.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.169-174
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• 2011

The synthesis of new pyrazolyl and cyclopropyl derivatives of purpurin-18 methyl ester and purpurin-18-N-butylimide 1a, 1b, 2a, 2b and 8 is described. The new compounds were characterized by NMR, UV-vis spectroscopy and mass spectrometry. UV-vis spectra of the new compounds showed long wavelength absorption of ranges 692 - 708 nm ($\lambda_{max}$). Photodynamic effects of the chlorin derivatives 1a, 1b, 2a and 2b were investigated by WST-1 assay in A549 cells, and showed good photodynamic activities with high photocytotoxicity and low cytotoxicity in the dark. In comparison between pyrazolyl and cyclopropyl derivatives, purpurin-18 methyl ester compounds 1a and 1b showed comparable photocytotoxicity result of the cell viabilities, otherwise, pyrazolyl derivative of purpurin-18-N-butylimide 2a showed better cell viabilities than those of cyclopropyl derivative 2b. And cyclopropyl derivative of purpurin-18-N-butylimide 2b showed higher dark cytotoxicity than that of others.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.26-31
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• 2012

A new operational concept for the CNS/ATM using the digital data communication technology and satellite navigation system is being implemented globally and the United States is the first country to apply UAT ADS-B system for general aviation. Korea also has plan to build ADS-B system for aeronautical surveillance to monitor low altitude flight of light aircraft and ultra-light flying device and the research to develop UAT ADS-B equipment is being carried out. This paper presents the application method of UAT ADS-B to support test operation with case study of foreign UAT ADS-B operation and survey of domestic environment.

• Asia pacific journal of information systems
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• v.14 no.1
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• pp.59-77
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• 2004

Even though B2B EC is becoming popular, there have been not so much studies about performance evaluation methodology for B2B systems. In this paper, after analyzing buyer-carts systematically focusing on the buyer's interactional efforts on the typical buying processes of each buyer-cart, we propose a quantitative performance evaluation model. For this, we categorize buyer-carts in B2B EC as s-cart, i-cart, and b-cart depending upon its residing sites: seller, intermediary, and buyer sites. And after proposing the desired features of buyer-carts in B2B EC as identification, collection, trashing, ordering, payment, tracking, recording, purchasing decision support, and transmission of records to e-procurement systems, we derive a performance evaluation model by calculating detail sub-processes from the desired features' viewpoints. By setting variables from a survey on the actual condition of using buyer-carts in companies in Korea, we try to evaluate the performance of buyer-carts in B2B EC. In this paper, we suggest a new methodology of performance evaluation for B2B systems, and show that the b-cart platform is more efficient than other buyer-carts especially in B2B EC.

• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.229-243
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• 2003

This paper suggests the process of performance measurement system development for B2B e-Marketplace using BSC (Balanced Scorecard). As the first step, main features and factors affecting performance of e-Business company and especially of B2B e-Marketplaces were derived based on the literatures. For the 2nd step, the nonnative performance measurement model for B2B e-Marketplace was suggested. Especially, the research range that the model covers is restricted to the neutral and systematic sourcing B2B e-Marketplace. And, the performance measurement model was based on BSC, for the BSC is very powerful and sound tool among all the available performance measurement systems. Also, the model was based on the AHP (Analytic Hierarchy Process) to make the model more structured, and to draw weights of performance measures from experts

• The KIPS Transactions:PartD
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• v.12D no.6 s.102
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• pp.915-920
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• 2005

In this paper we expanded a existing web based B2B system to support users in low speed network. To guarantee shared dat a consistency between clients and a server, we proposed a method of data change detection by using a time stamp tree and the performance analysis of the proposed method was proved by a simulation. Under the worst condition that leaf nodes of a times tamp tree were changed uniform distribution, the simulation result showed that the proposed method was more efficient than a sequential detection until the percentage of changed nodes were below $15\%$. According to our observation, the monthly average of data change was below $7\%$ on a web-based construction MRO B2B system or a company A from April 2004 to August 2004. Therefore the Proposed method improved performance of data change detection in practice. The proposed method also reduced storage consumption in a server because it didn't require a server to store replicated data for every client.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.452-455
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• 2002

In terms of B2B, business partners require works that define their ability to operate business collaboration. The document outlining collaboration is the basis of improving the system of business partner and its interoperability. In addition, the definition of business interaction that is bastd on the documents demonstrating inter-cooperation of business companies is needed to function interoperability properly, and business trading is performed depending on the documents that define reciprocal action of collaboration. In ebXML, CPP(Collaboration-Protocol Profile) defines one business parter's technical capabilities to engage in electronic business collaborations with other partners by exchanging electronic messages. A CPA(Collaboration-Protocol Agreement) documents the technical agreement between two partners to engage in electronic business collaboration. In this paper, 1 draw up a plan for a system that deals with business collaboration document to ameliorate the interoperability of B2B companies.

• Journal of Information Technology Services
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• v.1 no.1
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• pp.17-27
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• 2002

Buyer-carts to support the purchasing process in the B2B EC platform, can be categorized as s-cart, i-cart, and b-cart depending upon its residing sites : seller, intermediary, and buyer sites. In this paper, after proposing the desired features of buyer-carts in B2B EC as identification, collection, trashing, ordering, payment, tracking, recording, purchasing decision support, and transmission of records to e-procurement systems, we try to analyze each buyer-cart qualitatively from such viewpoints. Moreover, we propose an efficiency evaluation model for quantitative analysis. By setting variables from interview of employees in 30 listed companies In Korea, we try to evaluate the efficiency of buyer-carts in B2B EC. From this paper, we show that the b-cart platform is more efficient than other buyer-carts especially in B2B EC.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.131-136
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• 2011

In this paper, we fabricate multi channel receiver for radar system. This receiver at X-band can be received 8 signal of an identical characteristic, dynamic range has more than 80[dB]. To process direct received signals, this system has the built-in two digital de-modulators which offer the minimum loss on the receiving signal path and has high stability by adding Built-In Test. The gain, noise figure, difference of amplitude and phase on the signal path is respectively 20${\pm}$2[dB], 19[dB], ${\pm}$2[dB], $10^{\circ}$ and below.

• Journal of the Korean Ceramic Society
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• v.20 no.3
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• pp.236-242
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• 1983

The purpose of present study is to find the structures physical properties and their inter-relations in the system of (60-x) PbO.xMO.$40B_2O_3$ glasses where MO represents for ZnO and CdO. The experiments such as differential thermal analysis infrared spectral analysis X-ray diffraction analysis density and thermal expansion measurements have been done. From infrared spectral analysis the structural units of glasses and the corresponding crystallized glasses were com-posed of $BO_3$ triangles and $BO_4$ tetrahedra. These basic units found in $PbO-B_2O_3$ binary glass system did not charge even though the divalent metallic oxides were substituted for PbO. The structures of these ternary glasses were more coalescenced than $PbO-B_2O_3$ binary glass system. This fact was supported bydecrease in thermal expansion coeffici-ent and molar volume with substitution of divalent metallic oxide for PbO. Crystalline phases obtained from the heat treatment of the $PbO-ZnO-B_2O_3$ glasses were 4PbO.2ZnO.$5B_2O_3$ PbO.2ZnO.$B_2O_3$ and unknown phases.