• 대한전자공학회논문지SD
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• 제47권2호
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• pp.100-105
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• 2010

본 논문에서는 Zero-Crossing 복조기에 적합한 88MHz에서 108MHz 대역 FM 라디오 수신기를 $0.5{\mu}m$ CMOS 공정을 이용하여 설계 및 제작하였다. 본 수신기는 Low-IF 구조를 기초로 설계되었으며, Low-Noise Amplifier (LNA), Down-Conversion Mixer, Phase locked loop (PLL), Low-pass filter (LPF), 비교기를 포함하는 RF/Analog 집적회로로 개발되었다. 측정결과 LNA와 Mixer를 포함하는 RF Block은 23.2dB의 변환 이득과 입력 PldB는 -14dBm였고 전체 잡음지수는 15 dB로 나타났다. IF단 LPF와 비교기를 포함하는 Analog Block은 89dB 이상의 전압 이득을 가지고, IC내부의 레지스터를 제어하여 600KHz에서 1.3MHz까지 100KHz 단위로 Passband 대역를 조절할 수 있도록 설계되었다. 설계된 수신기는 4.5V에서 동작하며, 전체 전류 소모는 15.3 mA로 68.85mW의 전력을 소모한다. 실험결과 성공적으로 FM 라디오 신호를 수신할 수 있었다.

• 한국식생활문화학회지
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• 제33권6호
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• pp.523-530
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• 2018

The purpose of this study was to develop a technology commercialization strategy by analyzing the consumer preference for low-sodium instant noodle ramen, which has a sodium content of 1,730 mg or less. For the commercialization of such low-sodium ramen, this study examined how much consumers would pay through an analysis of consumer preference by conjoint analysis. This study surveyed 1,004 men and women in their 20 s and 50 s between the ages of 20 and 50 years in Korea using an online survey. If the price of conventional instant noodle ramen is KRW 4,000 (approximately USD 3.57) per 5 packs for one pack of 5 servings in a supermarket, this study surveyed how much more they respondents would pay if the sodium was reduced by 10.0, 20.0, and 30.0%. The study found that if sodium was reduced by 10.0, 20.0, and 30.0%, the respondents would pay as much as KRW 4,180, KRW 4,307, and KRW 4,515, respectively. The attributes of low-sodium instant noodle ramen were examined according to the degree of sodium reduction, vegetable protein ingredients, brand, where to buy and price with each level. The Marginal Willingness To Pay (MWTP) was analyzed as follows. If the sodium content of ramen soup is reduced by 1.0%, the amount that can be paid would be KRW 105.78. Respondents could pay KRW 1,673 more for famous brand ramen than an unknown brand ramen. The study results indicated that when a new product is developed and released, it can be expected to increase sales of the new product by understanding the foreseeable value that consumers could pay for and realize the technological commercialization of the technology.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.288-290
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• 2006

An efficiency improving method for Uninterruptible Power Supply System(UPS) was developed by using OP-AMP based application circuits such as voltage detection device, current detection device and static switch control device. The efficiency improving algorithm was made by mixing the operating concepts of On-Line type UPS with the operating concepts of Off-Line type UPS. The UPS' inverter does not work if the UPS' output load current is not higher than the low load operating current which is about 0-30(%) of the UPS' output load capacity. The low load operating current is adjustable within the half of the UPS' output load capacity. If the UPS' output load current is rising over than the low load operating current, the UPS' inverter starts working and the inverter output power feeds to the loads of UPS. If UPS' input power breaks out while UPS' inverter does not operate because the load current is low, the inverter starts working within 4(ms) with excessive output voltage which is ${\pm}$8(%) of normal UPS' output voltage. Like these. UPS can continuously feeds power to it's load device and reduce power consumptions.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.414-417
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• 2008

This paper presents the design and analysis of 2.45GHz Low-IF Mixer using CMOS 0.18um. The Mixer is implemented by using the Gilbert-type configuration, current bleeding technique, and the resonating technique for the tail capacitance. And the design of this Double Balance Mixer is based on its lineaity since it is important in the interference cancellation system. The low flicker noise mixer is implemented by incorporating a double balanced Gilber-type configuration, the RF leakage-less current bleeding technique, and Cp resonating technique. The proposed mixer has a simulated conversion gain of 16dB a simulated IIP3 of -3.3dBm and P1dB is -19dBm. A simulated noise figure of 6.9dB at l0MHz and a flicker corner frequency of 510kHz while consuming only 10.65mW od DC power. The layout of Mixer for one-chip design in a 0.18-um TSMC process has 0.474mm$\times$0.39 mm size.

• 전자공학회논문지B
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• 제31B권10호
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• pp.73-81
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• 1994

It is AGC(Automatic Gain Control) amplifier to decide characteristics of IF(Intermediate Frequency) processing IC. When demodulated IF signal by PLL type demodulator, the amplitude of input singla should be maintained at a certain amplitude. The AGC amplifier is an important factor to achieve this condition. The AGC amplifier needs the wide dynamic range, the wide AGC range and better noise characteristics. We designed the AGC amplifier to satisfy these characteristics.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.132-133
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• 2015

In this research by examining the influence that low quality aggregate has on the strength of concrete through testing, the lowering of strength according to use of low quality coarse aggregate was reviewed. The results showed that when using low quality coarse aggregate, due to the quality of aggregate a high volume of units was required, and this caused the compression strength to be lowered. In conclusion it was confirmed that if the low quality aggregate was used as is without mix correction this would lead to faulty construction and if the aggregate was corrected to about 60 kg/m3 mix correction, this would lead to an economically infeasible concrete mix.

• ETRI Journal
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• 제33권6호
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• pp.969-972
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• 2011

This letter presents a CMOS RF front-end operating in a subthreshold region for low-power Band-III mobile TV applications. The performance and feasibility of the RF front-end are verified by integrating with a low-IF RF tuner fabricated in a 0.13-${\mu}m$ CMOS technology. The RF front-end achieves the measured noise figure of 4.4 dB and a wide gain control range of 68.7 dB with a maximum gain of 54.7 dB. The power consumption of the RF front-end is 13.8 mW from a 1.2 V supply.

• 디지털산업정보학회논문지
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• 제19권1호
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• pp.129-138
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• 2023

The purpose of this study is to explore factors that directly affect the employment of college graduates. To this end, employment data of graduates of private four-year university in Daegu metropolitan area and Gyeongsangbuk-do province were collected from 2019 to 2021, filtered data using a RapidMiner, and analyzed by applying a decision tree model. As a result of the study, long-term internship for more than 12 weeks, TOEIC score of 787.5 or higher was advantageous for employment, and if there was no TOEIC score, the graduation average score was 3.67 or higher, so the possibility of employment was high. Even if the TOEIC score was low, it was advantageous for employment if participating in the contest and continuous professor counseling, and even if the average graduation score was low, the possibility of employment was high if actively participating in the comparison program. This study can present a job education guide based on actual data to university management and use it to establish policies to support employment of college students.

• 한국전문물리치료학회지
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• 제12권3호
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• pp.84-93
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• 2005

The purpose of this study was to find prevalence and the relevant factors of low back pain among taxi-drivers. Information were obtained by a self-administered questionnaire during september, 2004, from 83 taxi-drivers in Gimhae, Kyung Nam province. The data were analyzed by chi-square test and Multiple Logistic Regression(if this is a proper noun, it needs to be capital, if not it needs lower case) by using SPSS 10.0 program. The result were as follows: 1) The prevalence rate of low back pain during lifetime was 81.9% among 83 taxi-drivers. 2) Statistically significant factors related to low back pain during lifetime were sleeping time(p<.05). 3) Through the multiple logistic regression, significantly relevant factors with low back pain were alcohol drinking (OR=.017, 95% CI=.001~.509), and sleeping time (OR=.111, 95% CI=.020~.636). It is necessary to study on a preventive measure of low back pain and systematic human engineering approach through objective clinical research.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.941-944
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• 2015

본 논문에서는 여러 대역의 주파수를 하나의 모듈로 통합하여 선박이 해외 각국에서도 하나의 위성안테나로 사용할 수 있는 다중대역 FEM(Front-End Module)모듈을 설계하였다. 설계된 FEM은 다중대역 저잡음 수신 증폭회로, 주파수 변환 회로, IF 증폭회로, 전압 제어 발진기(VCO : Voltage Control Oscillator)를 이용한 신호발생회로 네 가지 회로로 구성하였다. 다중대역 2.05GHz대역을 변환하기 위하여 4개(대역1, 대역2, 대역3, 대역4)의 국부 발진 신호를 생성하여 4개의 IF신호를 출력하도록 설계하였으며 개발된 변환 장치는 변환이득 64dB, 잡음지수 1dB 이하, 출력 P1dB 15dBm 이상, 위상잡음은 -73dBc@0.1KHz를 나타내었다.