• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.35-44
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• 2006

Reflective semiconductor optical amplifiers(R-SOAs) were designed with high gain, wide optical bandwidth, high thermal reliability and wide modulation bandwidth in TO-can package for the transmitter of wavelength division multiplexed-passive optical network(WDM-PON) application. Double trench structure and current block layer were introduced in designing the active layer of R-SOA to enable high speed modulation. The injection power requirement and the viable temperature range of WDM-PON system are experimentally analysed in based on Amplified Spontaneous Emission(ASE)-injected R-SOAs. The effect of the different injection spectrum in the gain-saturated R-SOA was experimentally characterized based on the measurements of excessive intensity noise, Q factor, and BER. The proposed spectral pre-composition method reduces the bandwidth of injection source below the AWG bandwidth and thereby avoids spectrum distortion impeding the intensity noise reduction originated from the amplitude squeezing.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.2
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• pp.45-52
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• 2008

The telecommunication facilities by the basic law of telecommunication were added to the protection law against natural disasters as a scope of seismic design application on January 2007 since legal regulation had been reinforced in our country as in the circumstance that earthquakes are now frequently occurred in several areas over the world. This paper handles an establishing provision of concrete seismic design specification for applying to telecommunication facilities. For this purpose, this paper classified the parts of telecommunication facilities as being the correspondents to apply seismic design and analyzes the procedure of the design specification of building structure as the part of building construction law as a basic reference for seismic design application. And the method of introducing the foreign specification is presented. Thereon seismic design measures to be introduced into legal regulation are suggested for telecommunication service endurance against earthquake.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.553-562
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• 2007

Consumer needs becomes various in a mature mobile telecommunication market, while service differentiation is hard to achieve. Because of the introduction of number portability, switching barrier becomes lower and the competition among telecommunication service providers is getting fierce in order to maintain and obtain customers. Moreover, HSDPA, which is a new telecommunication service, caused the intense marketing activity for the move to the next generation customers. Under these circumstances, brand equity can be a key to a long-term competitive edge for mobile phone service providers. However, there were few researches reporting the mobile telecommunication brand equity, and none of them analyzed if customer equity which particularly is developed at the CDMA market has an effect on HSDPA service. In this study, we identified the determinants of mobile telecommunication brand equity, which is focused on brand image, customer benefit, price, service quality, and marketing activity, and its influence on the HSDPA service subscription behavior. Finally, we suggested the strategic implication of brand management strategies for mobile phone service providers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1383-1389
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• 2013

There were telecommunication noise and malfunctions of the electronic devices occurred over a wide area due to the high harmonic voltage and/or current levels of the Back-to-back converter in the DFIG wind power system even though the magnitude of all harmonics is within the international standards. The triangular carrier signals of the PWM used in the power converter system is related to the telecommunication noise because they are in the range of audible frequencies and amplified by a variety of the standing waves that were excited by harmonic voltage sources in the weak grid system such as a long distance distribution transmission lines. This paper describes the characteristics of the harmonics in the wind turbine-generator, numerical analysis and simulation of the harmonics resonance phenomena in the distribution lines as well as measuring induced voltage of the telecommunication lines in parallel with power lines in order to verify the root cause of the telecommunication noise. These noise problems can occur in a wind turbine power system with a non-linear converter at any time, as well as photovoltaic power system. So, the preliminary review of suitable filter devices and switching frequencies of the PWM have to be required by considering the stability of the controller at the design stage but as part of the measures the effect of the telecommunication cable shields was analyzed by comparing the measured data between multi-conductor with/without shields so as to attenuate the sources of the harmonics voltage induced into the telecommunication lines and to apply the most cost-effective measures in the field.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.431-436
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• 2009

As the telecommunication lines bring into widespread use, one of the most important aspects related to power distribution systems is effectively to evaluate the effect on the telecommunication lines from power lines. One of the efficient methods to evaluate the effect is to measure the induced voltage of a telecommunication line as a result of a ground-loop. If the power lines cause high induced voltage, the ground reference in the telecommunication lines is no longer a stable potential, so signals may ride on the noise. A ground loop is common wiring conditions where a ground current may take more than one path to return to the grounding electrode at the arrangement between the power lines and telecommunication lines. When a multi-path connection between the power lines and telecommunication line circuits exists, the resulting arrangement is known as a ground loop. Whenever a ground loop exists, there are potential for damages or abnormal operations of the telecommunication lines. The power lines can induce the voltage on the communication line. The effects can be calculated by considering the inductances and capacitances. However, if we assume that there are only power lines, it doesn't have a practical meaning because there are conductors with other purpose in the neighborhood of the lines. If we consider that case, we need more complex system. Therefore we suggest more complex system considering the conductors with other purpose in the neighborhood of the lines. The neutral wires and the overhead ground wires are considered for calculating the induced voltage. We assume that there are the messenger wires beside the power line as a result of increased use of them. The main purpose of this paper is a study on a shielding effect of messenger wires in the distribution lines. EMTP(Electro-Magnetic Transients Program) program is used for the induced voltage calculation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.355-363
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• 2006

A rapidly increasing demand of voice and data through mobile telecommunication service and the development of technologies related with the service are sufficiently said to make the service become an indispensible communicating means, not just selective one. However, in the other side of the generalizing of mobile telecommunication service, there is said to be a worsening situation of unbalanced benefits due to the problem of information difference between the non. The more advanced mobile telecommunication service proceeds, the more deepens the problem, and it is generally known that the problem cannot be solved by the ability of free market itself as seen in the wired telecommunication market. Therefore, we need to set up a systematic policy of mobile telecommunication service for solving this problem, and also think over whether to include the service within the range of universal service. In this study, we examine the required factors for including the service within the range of universal service, and analyze the validity of the including in the view point of institutional aspects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1200-1205
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• 2002

Construction of Private networks is becoming easier due to the openness of telecommunication market, rapidly developing telecommunication technology. The size of existing private networks is becoming huge which resulted in surplus of capacity of the networks. These trends will generate a problem of efficient use of national telecommunication resources and which will be a factor for the structure of domestic telecommunication market which will have a big impact on the existing telecommunication carriers. Therefore, national policy of private network issues should be considered along with the national efforts for the information infrastructure, control of telecommunication market, fairness of competition, strength Power of national competition. In this paper it will be suggested that the efficient policy on the issue of domestic private network, by analyzing present situation, status quo, laws, regulation and procedure for domestic private networks and comparing it with those of U.S.A, Japan, EU.

• Journal of the Korean Institute of Educational Facilities
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• v.9 no.5
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• pp.5-12
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• 2002

High-speed telecommunication has brought variety of changes in every field of the world at large. In the field of education, use of multimedia has been positively introduced as teaching and learning tools. In addition, introduction of remote education as well as information and communication technology (ICT) has led an educational system gone into melting pot. These changes have known to be impossible without the provision of the infrastructure of telecommunications such as cabling, cable pathway, telecommunication equipments, and space for the equipments. Although the infrastructure of telecommunications should be fully considered from the early stage of the building design, most of the existing buildings have only cabling for voice communication such as telephone. As a result, heavy expenses are required for the installation of new telecommunication equipments. Such problems as defilement of the appearance of the building and a falling-off in reliability of telecommunication line are caused by the exposed cabling, when the cabling pathway and/or the space for the equipments are not reserved. Considering over 70% of error in telecommunication is coming from the cabling in building, it is necessary to reserve the space for efficient maintenance of the cabling and the equipments. In recent years, the national standard(TTAS.KO-04.0005) on the reservation of space for telecommunication cabling and equipments in residential and commercial building is established and applied for the building design. As well, the standard is in force for the educational buildings. In this study, we try to provide the guidelines for the design of telecommunications infrastructure in educational buildings for the purpose of efficient operation of education information and ICT.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.7
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• pp.46-56
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• 2002

In this paper, we describe a hardware-software co-verification methodology and environment in developing a mobile station modem chip for cdma2000 1x which is one of the 3rd generation mobile communication standards. By constructing an efficient co-verification environment for a register-transfer-level hardware model and a physical-layer software model combining a channel link simulator and a versatile test-bench, we can drastically reduce both time and cost for developing a complex three-million-gate class system integrated circuit.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.11a
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• pp.89-92
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• 2000

Non-aqueous tape casting of LTCC with PVB binder has been studied in a continuous tape casting machine. The aim of the study was to evaluate this type of system in the different Binder/Plasticizer and solid content compositions. Each four slurry compositions were used in the experiments with varied binder/plasticizer and solid content. All the slurries gave good quality tapes with smooth surfaces without blisters or pinholes. The highest mechanical properties was obtained for the B/P=3.0, powder content 70vol% composition from 52 ${\mu}{\textrm}{m}$ green tapes, a tensile strength of 4.6 MPa and a linear extension of 29.5%