• Journal of Engineering Education Research
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• v.15 no.3
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• pp.12-21
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• 2012

The purpose of this study is to verify the effects of mastery goal orientation and time management ability on job search self-efficacy in the vocational education of engineering college students. A total of 52 samples were analyzed for this research. The result indicated that mastery goal orientation had positive effects on all sub-variables (job ability self-efficacy, career goal setting self-efficacy) of job search self-efficacy significantly. But time management ability had positive effects on career goal setting self-efficacy. And there are no significant differences in mean comparison of mastery goal orientation, time management ability, and job search self-efficacy according to gender and residence area. In addition, the interview results of engineering college students' perception of career, the understanding of vocational education, and job search self-efficacy were analyzed.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.25-31
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• 2015

In this paper, we propose PEP based on cross-layer and network coding in digital video broadcasting-return channel via satellite (DVB-RCS) networks. In particular, we propose not only a scheme of cross-layer information exchange for interaction between TCP and the resource allocation (RA) scheme in the link layer but also a tuning algorithm for the TCP contention window (CWND) by using information on the RA in the link layer and the redundancy rate for network-coded packets. The simulation results show that TCP CWND can be adjusted by RA information in the proposed protocol. Furthermore, through the transmission of network-coded packets and the proposed CWND tuning algorithm, TCP throughput is enhanced in lossy environment due to user mobility without the unnecessary resource overhead.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1130-1137
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• 2009

This paper proposes a new clock routing design for suppressing clock harmonic effects in a Printed Circuit Board (PCB) for a terrestrial Digital Multimedia Broadcasting(DMB) system. Typical crystal reference frequencies that are widely used in DMB tuners are 16.384 MHz, 19.2 MHz, 24.576 MHz. When the high-order harmonic components of these reference frequencies fall near the RF channel frequencies, receiver sensitivity of the tuners is seriously degraded. In this work, we propose a new clock routing design in order to address the clock harmonic coupling issue. The proposed design incorporates two inductors for isolating the clock ground from the main ground, and adopts a new strip line-style routing instead of the conventional microstrip line style routing to minimize the overlap area with the main ground. As a result, the RF sensitivity of the T-DMB tuner is improved by 2 dB.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.659-664
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• 2016

In this paper, we suggest operational trans-conductance amplifier(OTA) for current-mode FIR filter that can be used in a digital circuit system requiring high operating frequency and low power consumption. The current-mode signal processing is one of the very innovative design method for a low power consumption system with high operating frequency because it shows a constant power regardless of frequency. From the simulation result using 0.35um CMOS process, when Vdd is 2V, it is confirmed that the proposed circuit showed the dynamic range of the about 1V, about 50% of supply voltage and output current swing of about 0~200uA. Also, the power consumption was evaluated with about 21uW and the active size for an integration was measured with $71um{\times}166um$.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1147-1154
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• 2001

In this paper, we make plans for facilities, the 8-VSB DTV transmission system, installed in the near future, based on presently NTSC TV operating it. First of all we estimate transmission power for analog NTSC, digital 8-VSB terrestrial broadcasting and the effective condition of optimal receiving power result from it. It's also to estimate optimal receiving condition by using Longley-Rice's Field Strength calculating method that is to guess a profile between transmitting station and many receiving points. The 8-VSB DTV Propagation aims to high-speed transmission rates of 19.39Mbps datum to enable HDTV(High Definition Television) at NTSC 6MHz bandwidth. First of all, an optimization of field strength between transmission station and receiver must deal with considerable. Because of these reasons, 8-VSB DTV transmission needs effective extension for NTSC TV service coverage. Finally we present the transmitting output that is expected in changing NTSC VHF to DTV UHF for maintaining the transmitting output of NTSC TV that is equal to 8-VSB DTV in service coverage.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.901-906
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• 2009

This paper proposes a call admission control(CAC) method for wireless networks, which is based on the upper bound of a possibility distribution of handoff calls dropping rates. The possibility distribution is estimated in a fuzzy inference and a learning algorithm in neural network. The learning algorithm is considered for tuning the membership functions(then parts)of fuzzy rules for the inference. The fuzzy inference method is based on a weighted average of fuzzy sets. The proposed method can avoid estimating excessively large handoff calls dropping rates, and makes possibile self-compensation in real time for the case where the estimated values are smaller than real values. So this method makes secure CAC, thereby guaranteeing the allowed CDR. From simulation studies we show that the estimation performance for the upper bound of call dropping rate is good, and then handoff call dropping rates in CAC are able to be sustained below user's desired value.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.319-327
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• 2008

The purpose of study is to investigate the customer oriented transaction environment for the customers' convenience, the plan of public policy in regard to the customer oriented T-Commerce, and the consumption pattern of customers' commercial transaction, necessary for the marketing strategy by analyzing the demand for the T-Commerce with the purchase intention and maximum willingness to pay according to the demographic factors, the pattern of commercial transaction, and the technology innovation types. The results showed that there were statistically significant relations between consumer's willingness price to pay for the T-commerce and the consumer's technology adoption types, monthly internet shopping amounts, and weekly TV-home shopping hours. The simulations on a basis of multiple regression analysis for the T-commerce were illustrated by those factors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1191-1198
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• 2018

This paper illustrates not only the effectiveness of applying content quota system for on-demand video streaming platform, but also the effect of OTT regulation on copyright protection and cultural industry protection in a single market, focusing on the community's response to Netflix's entry into the EU market. Additionally, this paper examines on-demand video streaming services, growth of Netflix. The EU policy on the on-demand video streaming service market consists of 'portability' in the digital single market and content quota for copyright protection. In this paper, I analyze the market protection and the aspect of improving competitiveness of online streaming service industry. The EU is trying to protect the cultural industry and copyright protection in the region by applying and regulating the OTT business in content quota system, which has been applied only to European broadcasting companies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8C
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• pp.777-785
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• 2006

H.264 is the prominent video coding standard in various applications such as real-time video streaming and digital multimedia broadcasting, since it provides enhanced compression performance, error resilience tools, and network adaptation. Since compressed video stream is vulnerable to packet loss, error resilience and error concealment(EC) tools are essential for the transmission of video over the Internet. In this paper, we first propose a simple temporal EC method that improves the EC performance for intra-frame in H.264 when the amount of motion is relatively small. Then we propose a new hybrid EC method for intra-frame in H.264, which combines the spatial EC and temporal EC adaptively. The simulations are performed in packet-lossy environments, and the proposed hybrid EC method shows about 0.5-4dB PSNR improvement compared to the conventional spatial EC method that is used for intra-frame in H.264.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.153-158
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• 2007

The INMARSAT is able to long range maritime communications that can not use for expensive charge in non-SOLAS ship. Therefore, international discussion for the question that replacements use of MF/HF band for maritime distress and safety communications in maritime. HF data communications system may be effectively utilized for SOLAS ships as well as for the existing non-SOLAS vessels including the fishing boats, which navigate A2 and A3 sea areas. The HF data communications may have various functions such as e-mail services, broadcasting services of up-to-date information related to marine safety, position reporting services, polling services etc. However, the present HF e-mail communications protocols have a problem of increasing calling redundancy as the number of channels in operation increases. This paper new protocol and communication sequence proposed in this submission establishes a proper radio link automatically and adaptively by taking channel traffic into account.