• Journal of Practical Engineering Education
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• v.16 no.4
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• pp.499-512
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• 2024

In this study, we diagnosed the results and achievements of pilot operation of high-skilled meister course in degree-linked work-study in parallel, which has been carried out, and suggested of direction for improvement and desirable implementation. In the achievement diagnosis, the results of training served by the university operating this course, the performance and recognition of expert activities after graduation, the self-efficacy in the degree of strengthening one's capabilities as a corporate field teacher, and the self-efficacy for the degree of strengthening the company's human capabilities, and the government performance was diagnosed. Based on the analysis, various operational improvement directions were derived to revitalize high-skilled meister courses in degree-linked work-study in parallel. This study increased the reliability of the study by diagnosing and examining the empirical performance of the entire Advanced Meister Course pilot project through actual performance aggregate data and graduates who participated in the project. It also provides a theoretical basis for policy decisions by verifying implications and desirable directions for improvement through expert advice.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1276-1284
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• 1999

We have evaluated the BER's and CLP's of Wireless ATM (WATM) cells employing the concatenated FEC code with pilot symbols for fading compensation through the simulation in indoor wireless channel modeled as a Rayleigh and a Rician fading channel, respectively. The results of the performance evaluation are compared with those obtained by employing the convolutional code in the same condition. In Rayleigh fading channel, considering the maximum tolerance BER ( $10^-3$) as a criterion of the voice service, it is blown that the performance improvement of about 4 dB is obtained in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols rather than the convolutional code with pilot symbols.When the values of K parameter which means the ratio of the direct signal to scattered signal power in Rician fading channel are 6 and 10, it is shown that the performance improvement of about 4 dB and 2 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols considering the maximum tolerance BER of the voice service. Also in Rician fading channel of K=6 and K= 10, considering CLP = $10^-3$ as a criterion, it is observed that the performance improvement of about 3.5 dB and1.5 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.155-160
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• 1998

We applied a pilot symbol assisted modulation technique to QPSK system for improving BER performance over mobile communication channel. We demonstrate through computer simulation, that the proposed scheme achieves a prominent improvement comparison to that of conventional QPSK in a fast flat Rayleigh fading environment.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.307-308
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• 2008

In this paper, we propose a mitigation method to reduce the effect of pilot interference at the wireless repeater. This improves the signal to interference ratio (SIR), and enables increased cell capacity and better bits error rates (BER) performance in the WCDMA systems. Simulation studies have been carried out to verify the proposed approach and we obtained promising results.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.61-64
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• 2000

본 논문에서는 cdma2000 규격을 채용한 역방향 링크 동기식 DS-CDMA 시스템을 시뮬레이션 하여 시스템의 성능을 분석하려다 cdma2000 시스템은 기존의 IS-95와는 달리 Pilot 채널을 이용하여 페이딩 채널을 추정하고 이를 이용하여 채널 환경에 의한 수신신호의 위상변화를 보상해 준다. 채널 추정필이 31pcg 심볼에서 Pilot 채널과 Traffic 채널의 최적의 전력비를 구하였다. 또한 시스템에 Power Control을 적용하여 Target FER을 만족시키기 위한 required Eb/No를 구하였고, 서로 다른 데이터율의 사용자가 동시에 전송할 때의 성능을 분석하였다.

• New & Renewable Energy
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• v.2 no.2 s.6
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• pp.118-125
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• 2006

The target of this work was the process development of demonstration plant to produce the high quality alternative fuel oil by the pyrolysis of mixed plastic waste. In the first step of research, the bench-scale units of 70 t/y and the pilot plant of 360 t/y had been developed. Main research contents in this step were the process performance test of pilot plant of 360 ton/year and the development of demonstration plant of 3,000 t/y, which was constructed at Korea R & D Company in Kimjae City. The process performance of pilot plant of 360 t/y showed about 80% yield of liquid product, which was obtained by both light gas oil(LGO) and heavy gas oil(HGO), The boiling point range distribution of LO product that was mainly consisting of olefin components in PONA group appeared at between that of commercial gasoline and kerosene. On the other hand, HO product was mainly paraffin and olefin components and also appeared at upper temperature distribution range than commercial diesel. Gas product showed a high fraction of $C_3\;and\;C_4$ product like LPG composition, but also a high fraction of $CO_2$ and CO by probably a little leak of process.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.2
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• pp.1-11
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• 2020

This study was carried out to verify how much instructor's communication skill affects the student pilot's study motivation and satisfaction. The instructor's communication styles are classified into 3 groups by pre-analysis. Three types are cooperative type, control type and professional type. Intellectual cause, performance proficiency cause, social cause and stimulation avoidance cause are extracted and analyzed for the cause of study motivation. Cooperative and control type affected all of 4 factors of student's study motivation by influence analysis. Intellectual cause affected control and cooperative type positively, especially more to cooperative type. Performance proficiency cause also had positive influence to control and cooperative type. Stimulation avoidance cause didn't appear to affect all sub-classified 4 factors of instructor's communication type. Influence analysis of student's study satisfaction from instructor's communication style showed that independent variable affected all sub factors positively. Degree of positive influence affected the control type the most, cooperative type was the 2nd, and professional type was the 3rd.

• Journal of Family Resource Management and Policy Review
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• v.14 no.4
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• pp.101-126
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• 2010

This Qualitative case study focused on the National Pilot Project to make family-friendly communities. We examined the basic model of the family-friendly community proposed by the Ministry of Gender Equality and Family. One of the three local communities selected as family friendly models was chosen for observation and in-depth interview for its residents. The official performance report shows this project's process, results and future tasks. From the in-depth interview data, we defined the project's characteristics as the government and private sectors collaboration, model transformation from the original family friendly model to the production model, and we found some conflicts among residents upon financial issues and business items. The most important task is the vitalization of the community corporate body to realize this project's performance through these three years. And this study implicates to elaborate the rural family-friendly community model focused on income creating community redesign, different from the urban model focused on caring.

• KSBB Journal
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• v.24 no.1
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• pp.89-95
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• 2009

Biodiesel (fatty acid alkyl esters), which is produced from sustainable resources such as vegetable oil, animal fat and waste oils, have used to as substitutes for petro-diesel. In this study, we investigate the performance of 30 L and 300 L pilot-scale biodiesel production system using alkali-catalyst transesterification from soybean oil and rapeseed oil produced at Jeju island in Korea. The 30 L-scale biodiesel production was performed to in the condition of reaction temperature $65^{\circ}C$, catalyst amount 1% (w/w) and oil to methanol molar ratio 1 : 8. At that reaction condition, the fatty acid methyl ester contents of product are above 98% within reaction time 30 min. Also, the conversion yield of over 98% was obtained in 300 L-scale biodiesel production system using rapeseed oil and soybean oil. The quality of biodiesel produced from reaction system was satisfied to recommended quality standard of Korea. Our results may provide useful information with regard to the scale-up of more economic and efficient biodiesel production process.

• Journal of Broadcast Engineering
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• v.21 no.4
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• pp.552-561
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• 2016

In OFDM system, frequency-domain sub-carriers of a symbol generally consist of data sub-carriers and scattered pilot sub-carriers and in the receiver, channel is estimated through time-axis interpolating pilot sub-carriers of several OFDM symbols. However, time-axis interpolation fails to keep track of rapid channel variation caused by fast moving receiver. Although symbol by symbol channel estimation without time-axis interpolation enables fast estimation, the performance is severely degraded for a long delay spread channel in a single frequency networks (SFNs) because of insufficient pilot sub-carriers. In this paper, a channel estimation scheme for OFDM receiver in a fast mobile SFN channel is proposed. The proposed scheme is applied to DVB-T receiver to improve the Doppler mobile performance in SFN channel.