• Proceedings of the IEEK Conference
• /
• 2002.07c
• /
• pp.1752-1755
• /
• 2002

The world wide web (WWW) already accounts f3r more Internee network traffic than any other application, including il and simple file transfer. It is also a collaborative technology in a weak sense of the word - it allows people to share information. Synchronous collaboration is where an interactive activity is simultaneous and in teal-time. Computer based real time collaborative systems like shared whiteboards. collaborative editor etc. are only beginning to emerge recently. These applications invoking more than two users exchanging information, require Multicast communication. Multicast communication is a transmission mode that is now supported by a variety of local and wide area networks. Multicasting enables multiparty communication across a wide area to sparsely distributed groups by minimizing the network load. Multicasting itself is one of the key technologies in the nut generation of the Internet This paper describes the technical issues from the aspect of multicast communication and its reliability in synchronous collaborative application.

• Journal of Veterinary Clinics
• /
• v.9 no.2
• /
• pp.473-481
• /
• 1992

To elucidate the applicability of the wide latitude X-ray film for radiographic diagnosis and treatment of diseases in small animals, the quality of the wide latitude film was compared with that of the standard latitude film which is commonly used in veterinary clinic. The images of head, neck, thorax, abdomen, extremities and joints were radiographed with the wide latitude and standard latitude film in fourteen dogs. In soft tissues such as abdominal organs, lung, skin, mammary glands, the clearer and higher contrast of the image was observed on the wide latitude film. And these advantages were more apparent in pneumoeritoneography. Therefore. it can be suggested that the wide latitude film is practically useful for the evaluation of the images of soft tissues, and also can be used on hard tissue radiography with the same quality as the standard latitude film.

• Korean Management Science Review
• /
• v.11 no.1
• /
• pp.129-144
• /
• 1994

B-ISDN(Broadband Integrated Services Digital Network)which is defined as a service or system requiring transmission channels capable of supporting rates above 1.5 Mbps has emerged as a new future telecommunication infrastructure. B-ISDN can integrate a wide range of services and the success of B-ISDN is crucially dependent on the development of user-needing application services. The purpose of this study is the conceptual development of B-ISDN application services. We survey on the kinds of B-ISDN service, classify application areas by user groups, and develop B-ISDN application services. Finally we categorize B-ISDN application services by their application areas and necessary services.

• The Journal of Information Technology and Database
• /
• v.8 no.1
• /
• pp.105-116
• /
• 2001

XML is a standard markup language for exchange and storage of formed or well-formed information in World Wide Web. Because the source data of XML message for exchange of information in World Wide Web is stored in legacy database, it is necessary for the easy connection between XML application and database system. In Oracle8i, 9i, Informix and SQL2000, DBMS vendors make upgrade to DBMS for using XML. This method of upgrade between XML application and database system is Platform-dependent and DBMS-dependent. Also It is necessary for the method of the platform- and DBMS-independent connection between XML application and database system. The methods for the connection between XML DTD and RDB schema are studied for the easy connection between XML application and database system. But the study for the easy connection between XML DTD and ORDB schema is a little. For multimedia application, we use the extended DBMS from RDBMS. It is necessary for the study to the transformation from XML DTD to ORDB schema. In this paper, for easier connection between XML application and database system, we propose the method of the transformation from XML DTD to ORDB schema using Object Model.

• Proceedings of the KIPE Conference
• /
• 2018.07a
• /
• pp.522-524
• /
• 2018

A New Direct AC LED Driver has been proposed for wide output power range and precise constant current regulation using an advanced auto commutation topology. The conventional shunt regulation method provides a stepped input current shape by fixed regulation references in the linear regulator of the each channel, which results in poor current regulation and high THD. The conventional method needs to assign a linear regulator in each LED channel so that the number of linear regulator increases when extending the number of channels especially at high power application. The proposed regulation method can drive multiple switches to regulate each LED channel current by a single amplifier with sinusoidal reference so that large number of LED channel can be simply extended with less BOM cost and low THD is obtained with the accurate current regulation thanks to the sinusoidal input current control in the closed loop control. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a 20-W LED driver prototype are presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.04a
• /
• pp.36-36
• /
• 2008

Organic light-emitting device (OLED) have become very attractive due to their potential application in flat panel displays. One important problem to be solved for practical application of full-color OLED is development of three primary color (Red, Green and Blue) emitting molecule with high luminous operation. Particularly, the development of organic materials for blue electroluminescence (EL) lags significantly behind that for the other two primary colors. For this reason, Flu-Si was synthesized and characterized by means of high-resolution mass spectro metry and elemental analyses. Flu-Si has the more wide optical band gap (Eg = 3.86) than reference material (Cz-Si, Eg = 3.52 eV). We measured the photophysical and electrochemical properties of Flu-Si. The HOMO-LUMO levels were estimated by the oxidation potential and the onset of the UV-Vis absorption spectra. The EL properties were studied by the device fabricated as a blue light emitting material with FIrpic.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.5
• /
• pp.999-1004
• /
• 2012

In this paper, camera modules and lens's images were analyzed for the compensation of distortion image by wide angle lens based WDR(Wide Dynamic Range) with high resolution sensor(2-Mega CMOS Image sensor). Due to wide angle ($176^{\circ}$) of designed wide angle camera modules, the compensation result of distorted image was analyzed, and the application of these modules was proposed for smart NUX(Natural User eXprience).

• The monthly packaging world
• /
• s.228
• /
• pp.72-75
• /
• 2012

• Journal of Power Electronics
• /
• v.18 no.4
• /
• pp.985-996
• /
• 2018

The implementation and performance evaluation of an interleaved boundary conduction mode (BCM) boost power factor correction (PFC) converter is presented in this paper by employing three wide band-gap switching devices: a super junction silicon (Si) MOSFET, a silicon carbide (SiC) MOSFET and a gallium nitride (GaN) high electron mobility transistor (HEMT). The practical considerations for adopting wide band-gap switching devices to BCM boost PFC converters are also addressed. These considerations include the gate drive circuit design and the PCB layout technique for the reliable and efficient operation of a GaN HEMT. In this paper it will be shown that the GaN HEMT exhibits the superior switching characteristics and pronounces its merits at high-frequency operations. The efficiency improvement with the GaN HEMT and its application potentials for high power density/low profile BCM boost PFC converters are demonstrated.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.6
• /
• pp.317-322
• /
• 2006

A accurate potential transformer(PT) with the nominal ratio errors in the wide range of - 9 % to + 11 % has been developed. The developed wide ratio error PT can be used to evaluate the linearity of the PT comparator by comparing both the theoretical values as standard values and experimental values of the PT. The new method has been successfully applied for calibration and correction in the PT comparator including very low ratio error values from ${\pm}0.005%$ to ${\pm}0.3%$ belonging to industry.