• Smart Structures and Systems
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• 제1권1호
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• pp.63-82
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• 2005

This paper introduces a technology for robust and low maintenance cost sensor network capable to detect accelerations below a micro-g in a wide frequency bandwidth (above 1,000 Hz). Sensor networks with such performance are critical for navigation, seismology, acoustic sensing, and for the health monitoring of civil structures. The approach is based on the fabrication of an array of high sensitivity accelerometers, each utilizing Fabry-Perot cavity with wavelength-dependent reflectivity to allow embedded optical detection and serialization. The unique feature of the approach is that no local power source is required for each individual sensor. Instead one global light source is used, providing an input optical signal which propagates through an optical fiber network from sensor-to-sensor. The information from each sensor is embedded onto the transmitted light as an intrinsic wavelength division multiplexed signal. This optical "rainbow" of data is then assessed providing real-time sensing information from each sensor node in the network. This paper introduces the Fabry-Perot based accelerometer and examines its critical features, including the effects of imperfections and resolution estimates. It then presents serialization techniques for the creation of systems of arrayed sensors and examines the effects of serialization on sensor response. Finally, a fabrication process is proposed to create test structures for the critical components of the device, which are dynamically characterized.

• 한국통신학회논문지
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• 제35권11A호
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• pp.1085-1090
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• 2010

Ultra wideband (UWB) technologies have been developed to exploit a new spectrum resource in substances and to realize ultra-high-speed communication, high precision geolocation, and other applications. The energy of UWB signal is extremely spread from near DC to a few GHz. This means that the interference between conventional narrowband systems and UWB systems is inevitable. However, the interference effects had not previously been studied from UWB wireless systems to conventional mobile wireless systems sharing the frequency bands such as Cellular CDMA and Korean PCS. This paper experimentally evaluates the interference from two kinds of UWB sources, namely a direct-sequence spread-spectrum UWB source and an impulse radio UWB source, to a Cellular CDMA and K-PCS digital transmission system. The average frame error rate degradation of each system arc presented. From these experimental results, we show that in all practical cases UWB system can coexist with Cellular CDMA and K-PCS terminal without causing any dangerous interference.

• 대한전자공학회논문지
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• 제27권9호
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• pp.1427-1435
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• 1990

This paper proposes the Selected Harmonic Elimination Pluse Width Modulation (SHE PW) scheme toreduce the ahrmonic components of source line current. To eliminate the low order harmonics which affects the source dominatly, we apply the Fourier series analysis to line current waveforms and then find out the switching patterns using the SHE PWM scheme. In addition to the analysis of harmonic effects, the three phase filter circuit is used to reduce high order harmonics. For the experimental realization, the converter circuit with power Transistor(PTR) is designed and the Pulse Time Control(PTC) is applied. The line current and the load voltage are measured under the condition of three phase application, highly inductive load.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.285-287
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• 2016

이황화 몰리브덴(Molybdenum disulfide: $MoS_2$)을 채널(Channel) 물질로 이용하여 metal-oxide-semiconductor(MOS) 구조를 제작하고, 효율적인 제작과정을 제시하였고 특히, Source/Drain의 Doping concentration을 조절하여 효과적인 $MoS_2$ Transistor를 제작 및 시뮬레이션 하였다. 그 후 여러 MOSFET의 특성 분석을 통하여 소자로서의 기능을 확인해보았다. 그리고 특히 채널의 전기적인 특성을 분석하고 채널 내 그리고 contact 사이의 저항 및 mobility의 특성을 알아보았는데, 그 중 Source/Drain Doping Effect와 performance 분석을 통해, 최적화된 $MoS_2$ Transistor를 찾아보았다.

• 인지과학
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• 제13권2호
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• pp.25-36
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• 2002

표적속성과 추론과제에 따라 속성추론의 양상이 달라지는지 알아보기 위해 두 개의 실험을 실시하였다. 근거대상이 주어지는 수동적 추론과제에서 표적속성이 해부적인 속성일 때에는 근거대상과 목표대상 간의 전반적 유사성이 중요한 것으로 드러났으나. 표적속성이 능력일 때에는 특별한 경향이 없었다 근거대상을 선정하는 능동적 추론과제에서도 표적속성이 해부적 속성일 때에는 수동적 추론에서와 마찬가지로 목표대상과 전반적 유사성이 높은 대상이 선정되었으나. 표적속성이 능력에 관한 속성일 때에는 표적속성에 대해 연상이 높은 동물이 근거대상으로 선정되는 경향을 보였다. 이 결과는 사람들이 속성의 종류에 따라 정보의 유관성이 다른 것은 알지만 구체적으로 유관 정보를 찾아내지는 않는다는 것을 시사하는 것으로 해석되었다.

• 지식경영연구
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• 제12권5호
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• pp.1-10
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• 2011

Forming a network, through Social Network Services (SNS), among a group of people who share the same hobby or interests could increase the information sharing among the members at an exponential rate. Moreover, SNS users' behavior extends beyond the traditional introverted consumption behavior to a proactive behavior by owning or actively sharing product information. For firms, such proactive consumer behavior translates into marketing effects such as the word of mouth (WOM) effect. Therefore, SNSs are accepted not only as a communications channel between firms and consumers but also as marketing channel, suggesting the possibility of a new revenue source. In this context, we will explore into the factors of SNS contents which conserve firms' image and product information, and effects of the factors on consumer attitude and WOM.

• 보존과학회지
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• 제37권1호
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• pp.1-12
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• 2021

In the digital era, large archives of information and Internet accessibility make information search, including image search, easier and affordable, even from remote locations. Information transmission and sharing can be performed instantly, at any moment. In the case of images, there are risks of transmitting and recklessly sharing intentionally modified images. Such modified images can also be transmitted and used as an additional source of information by followers. In this study, historical portraits of Yu Kil-Chun are shown, who was the first Korean student to study in both Japan and the United States. He was an intellectual, writer, politician, and independence activist of Korea's late Joseon Dynasty. Using image processing software, the portrait images were compared to investigate aging effects and artificial modifications. Statistics of red (R), green (G), blue (B), and L^*, a^*, and b^* values of every pixel in the selected identical areas of the portraits were compared to identify possible causes of variations, including aging effects and artificial modifications. Sepia toning, used in black and white photographs until the 1930s, and modern digital sepia toning can be very confusing owing to their aging effects. The importance of preservation of physical copies and preservation of context (interconnections between data and between documents) is discussed from archiving and conservation science perspectives.

• 복식문화연구
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• 제8권3호
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• pp.450-459
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• 2000

The purpose of this study was to test the effect of the clothing purchasing situation on the preceived risk and information search behavior. Data were obtained from 369 students who were studying in Semyung University. The results of this study were as follows : 1. Students gave the clothing to their favorites as a gift 1 to 2 times in a year. And they thought self using purchasing was more important than gift giving purchasing. 2. In gift giving purchasing, perceived risks were higher than self using purchasing. But the economic risk was the exception. In that case, students showed more information search behavior except family search source. 3. According to the situation, main and interactive effect of sex and involvement level on perceived risk and information search behavior were significant. In self using purchasing, involvement level had the main effect to the type of information search behavior. But the family search source was the exception Also in gift giving purchasing, they showed the same results. In self using purchasing, main effects of sex and involvement level on perceived risk were significant. Also in gift giving purchasing, they showed the same results, but the socio-psychological risk was the exception.

• 정보통신설비학회논문지
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• 제11권1호
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• pp.10-15
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• 2012

Ultra wideband (UWB) technologies have been developed to exploit a new spectrum resource in substances and to realize ultra-high-speed communication, high precision geo-location, and other applications. The energy of UWB signal is extremely spread from near DC (Direct Current) to a few GHz. This means that the interference between conventional narrowband systems and UWB systems is inevitable. However, the interference effects had not previously been studied from UWB wireless systems to conventional wireless systems sharing the frequency bands such as broadcasting system. This paper experimentally evaluates the interference from two kinds of UWB sources, namely an orthogonal frequency division multiplex UWB source and an impulse radio UWB source, to a broadcasting transmission system. The S/N ratio degradation of broadcasting system is presented. From these experimental results, we show that in all practical cases UWB system can be coexisted 35m distance in-band broadcasting network.

• International Journal of Contents
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• 제16권1호
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• pp.10-24
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• 2020

As many brands use social media influencers (SMIs) on Instagram to advertise, not disclosing advertised content affects how consumers perceive these influencers. The purpose of this study was to investigate two objectives: 1) recent advertising disclosure types on Instagram and 2) the factors that affect consumer responses towards Instagram influencers posting advertised content. Using an experimental 2x2 between-subjects design (N=200), the findings show that "sponsored" and "paid partnership with" are two recent types of ad disclosures. However, both factors are insignificantly different from each other. Also, ad disclosure condition enhances the trustworthiness of the influencer than no disclosure. Ad skepticism, source credibility, and the level of persuasion strongly relate to how consumers perceive Instagram influencers advertising for brands. These factors enable consumers to assess if the influencer is a reliable source of information when faced with advertisement. Ultimately, using disclosure gives full information to consumers about the persuasive intent, as well as increases positive consumer responses towards the influencer who discloses, thereby, enhancing the ethical use of the influencer advertising strategy and long-term consumer relationship.