• 복식
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• 제50권6호
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• pp.21-31
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• 2000

The purpose of this study was to characterize the attitudes of Net generation customers toward purchasing fashion products or apparels through Cyber communication media. This study targeted 333 individuals aged from 14 to 24 purchasing fashion apparels through the Interned or PC communication. The data were analyzed by using frequency analysis, factor analysis, t-test, ANOVA by SASS package. The results of this study are as follows : 1. Fashion life-style of Net generation is classified into four groups - Fashion attached type, Web entertainment type, Web information type, Web media purchasing type. Net-Generation shows a little preference for brand. 2. As a result of the statistical analysis of each group's demographic variables, price is not so important when purchasing and according to the analysis of age, it proves that twenties are trendier than teenagers. 3. The most significant factor of information search is watching others' clothes and the most popular place for purchase is wholesale mall. Net-Generation has a little intention to purchase through Cyber communication media.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.911-914
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• 2000

본 논문에서는 배터리가 없는 ASK 전송방식의 RFID(Radio Frequency IDentification) Transponder 칩 설계에 관한 내용을 다룬다. Transponder IC는 power-generation 회로, clock-generation 회로, digital block, modulator, overoltge protection 회로로 구성된다. 설계된 칩은 저전력 회로를 적용하여 원거리 transponder칩을 구현할 수 있도록 하였다. 설계된 회로는 0.25㎛ 표준 CMOS 공정으로 레이아웃하여 제작하였다.

• 대한전자공학회논문지TC
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• 제41권11호
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• pp.73-79
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• 2004

CDMA 시스템은 이동통신 환경에서 매우 적합한 방식으로 증명이 되었지만 다중경로간섭에 취약하여 주파수 선택적 페이팅 환경에서 고속데이터 전송을 하기 어려운 단점을 가지고 있다. 이 논문에서는 차세대 이동통신 시스템에서 사용될 수 있는 하향링크 전송방법을 소개한다. 제안된 전송 방법은 3세대 이동통신 시스템과 호환성을 유지하면서 수신기에서 주파수 영역 등화의 사용을 가능하게 한다.

• 전기학회논문지
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• 제59권12호
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• pp.2190-2194
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• 2010

Wind power generation system (WPGS) of Ulleung Island causes frequency and voltage fluctuation due to wind speed variation during night time. Superconducting magnetic energy storage (SMES) system can overcome the fluctuations through the fast response time of energy charging and discharging. The SMES system should be connected to the terminal of the WPGS for frequency stabilization. To demonstrated the effectiveness of SMES system for power quality improvement, Ulleung Island power network was modeled in a real time digital simulator (RTDS). The RTDS-based simulation results of power quality improvement with SMES are investigated and discussed in detail.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.145-148
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• 2003

Thermal characteristics according to the bearing preload arc studied for the four type spindles with high frequency motor. For the analysis. three dimensional models are built considering heat transfer characteristics such as natural and forced convection coefficients, Bearing and motor are main heat generation, and heat generation by ball bearings as a function of load. viscosity and gyroscopic moment effect are considered. Unsteady-state temperature distributions and thermal displacements according to the bearing preload are analyzed by using the finite clement method.

• 전자공학회논문지S
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• 제35S권3호
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• pp.9-18
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• 1998

For constructionof the next generation satellite B-ISDN/ATM networks considering integration with terrestrial information infrastructure networks, various high speed and wideband satellites with be launched and they will make used of frequency reue techniques for efficient management of limited frequency resource. Therefore, CCI(Co-Channel Interference) inherent in frequency reuse will be a dominant factor in performance degradation of satellite networks. This paper alanyzes the ATM cell transmission performance degradation caused by CCI. The satellite link, including up-link and down-link thermal noise, CCI, and nonlinear satellite transponder, is modeled and interleaving technique is used for compensating the ATM cell transmission performance degradation caused by burst error of satellite link. First, each satellite link subsystem is analyzed in detail and then end-to-end ATM cell transmission performance is evaluated with BER and CLR. Specifically, ATMcell transmission performance degradation caused by CCI is evaluated in detail.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.336-338
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• 2006

One of the important topics concerning the safety of electrical and electronic system is the reliability of the wiring system. The Time-Frequency Domain Reflectometry(TFDR) is a state-of-the-art system for detection and estimation of the fault on a wiring/cable. The purpose of this paper is to implement a Labview based TFDR Real Time system though the instruments of PCI extensions for Instrumentation(PXI). The TFDR Real Time system consists of the five parts: Reference signal design, signal generation, signal acquisition, algorithm execution, results diplay part. In the signal generation and acquisition parts we adopt the Arbitrary Waveform Generator(AWG) and Digital Storage Oscilloscope(DSO) PXI modules which offer commonality, compatibility and easy integration at low cost. And execution of the PXI modules not only is controlled by the Labview programing but also the total system process is executed by the Labview application software.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1724-1726
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• 2002

A novel ozonizer has been developed using a high-frequency surface discharge and a high purity alumina ceramic as its dielectric component. A thin ceramic layer, cylindrical in form, is adhered by a film-like induction electrode. An ac exciting voltage of frequency to 0.6 kHz from 1.0 kHz and $6{\sim}9kV$ peak-to-peak is applied between the electrodes to produce a stable high-frequency silent discharge for generation of ozone. A substantial reduction of the exciting voltage is also enabled by using a thin alumina ceramic layer. As a result, the ozonizer can easily produce ozone concentration($128g/m^2$ for oxygen) and power efficiency(360g/kWh for oxygen) without using a special enrichment means.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권2호
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• pp.170-183
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• 2013

This paper gives an overview of fractional-N phase-locked loops (PLLs) with practical design perspectives focusing on a ${\Delta}{\Sigma}$ modulation technique and a finite-impulse response (FIR) filtering method. Spur generation and nonlinearity issues in the ${\Delta}{\Sigma}$ fractional-N PLLs are discussed with simulation and hardware results. High-order ${\Delta}{\Sigma}$ modulation with FIR-embedded filtering is considered for low noise frequency generation. Also, various architectures of finite-modulo fractional-N PLLs are reviewed for alternative low cost design, and the FIR filtering technique is shown to be useful for spur reduction in the finite-modulo fractional-N PLL design.

• 통합자연과학논문집
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• 제14권2호
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• pp.50-56
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• 2021

Due to the recent increase in the mobile streaming market, mobile traffic is increasing exponentially. IMT-2020, named as the next generation mobile communication standard by ITU, is called the 5th generation mobile communication (5G), and is a technology that satisfies the data traffic capacity, low latency, high energy efficiency, and economic efficiency compared to the existing LTE (Long Term Evolution) system. 5G implements this technology by utilizing a high frequency band, but there is a problem of path loss due to the use of a high frequency band, which is greatly affected by system performance. In this paper, small cell technology was presented as a solution to the high frequency utilization of 5G mobile communication system, and furthermore, the system performance was improved by applying machine learning technology to macro communication and small cell communication method decision. It was found that the system performance was improved due to the technical application and the application of machine learning techniques.