• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.138-147
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• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.14-23
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• 2002

Two implementation methods for SOVA (Soft Output Viterbi Algorithm)of Turbo decoder are applied and verfied. The first method is the combination of a trace back (TB) logic for the survivor state and a double trace back logic for the weight value in two-step SOVA. This architecure of two-setp SOVA decoder allows important savings in area and high-speed processing compared with that of one-step SOVA decoding using register exchange (RE) or trace-back (TB) method. Second method is adjusting the reliability value with a scaling factor between 0.25 and 0.33 in order to compensate for the distortion for a rate 1/3 and 8-state SOVA decoder with a 256-bit frame size. The proposed schemes contributed to higher SNR performance by 2dB at the BER 10E-4 than that of SOVA decoder without a scaling factor. In order to verify the suggested schemes, the SOVA decoder is testd using Xillinx XCV 1000E FPGA, which runs at 33.6MHz of the maximum speed with 845 latencies and it features 175K gates in the case of 256-bit frame size.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.247-254
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• 2012

In this paper, we propose a concatenated diversity system to assure the data transmission reliability between flight type air nodes which move according to their atypical orbit, then its performance is analyzed using computer simulation and it is designed with hdl. The proposed system cannot only improve a bandwidth efficient and coding gain from diversity TCM code but also the reliability of data transmission is high. From the computer simulation result about bit error rate(BER) of the proposed system, we confirm that its BER performance is about 11dB greater than TCM code at $10^{-2}$ and about 11dB greater than space time block code at $10^{-3}$ which has a full diversity gain. In addition, when we compare its BER performance with space time trellis code which has both a diversity gain and a coding gain, the performance of the proposed system is greater than about 1.5dB at $10^{-5}$. Lastly, after designing the proposed system with HDL, we can confirm that the operation result is correct.

• Journal of Korean Public Health Nursing
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• v.18 no.1
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• pp.61-73
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• 2004

This study is intended to suggest fundamental data necessary for developing MBTI program that can help improve interpersonal relation skills of nursing science major students and their cohesion. This study is pre-experimental research by one group pretest-post test design to examine the effect of MBTI(Myers and Briggs Type Indicator) basic program on the interpersonal relationship between nursing science major students and their group cohesion and the relationship between interpersonal relationship and their group cohesion. I selected 39 of sophomore students in the department nursing science of K university in I metropolitan city as test group. 35 of them joined post-test. Pretest and MBTI basic program were done before conducting MBTI program. Collected data were analyzed by SPSS window 7.5. The difference in test group before and after conducting program was examined by paired t-test. The correlation between interpersonal relationship and group cohesion was measured by using Pearson Correlation Coefficient. The findings are as follows. $\cdot$ The difference before and after conducting MBTI program by sub-factors of interpersonal relation: There was no significant difference, as the average figure of interpersonal relation in test group was 87.22 before conducting MBTI and 85.08 after conducting MBTI respectively. The average figure of sensitivity among the sub-factors of interpersonal relation was 7.71 before conducting MBTI and reduced to 7.08 after conducting MBTI and there was significant difference between before and after conducting MBTI(t=-2.484, p=.018) $\cdot$ The difference in group cohesion before and after conducting MBTI program: The average figure of group cohesion in test group was 56.68 before conducting MBTI and increased a bit to 56.80 after conducting MBTI\, but there was no significant difference between them. $\cdot$ The relationship between interpersonal relationship and group cohesion before and after conducting MBTI: As the relationship between interpersonal relationship and group cohesion before and after conducting MBTI is examined, there was positive correlation of the significance level. p<.05 before conducting MBTI(r=.320, p=.047), and of the significance level, p<.01 after conducting MBTI(r=.780, p=.000). The investigation on the relation between sub-factors of group cohesion and of interpersonal relation before conducting MBTI basic program revealed that there was positive correlation between openness, reliability, friendliness and satisfaction, and group intervention, between receptivity among group members and reliability, and between group atmosphere and satisfaction. The investigation on the relation between sub-factors of group cohesion and of interpersonal relation after conducting MBTI basic program revealed that there was positive correlation between openness, communication, understanding, friendliness and satisfaction. and group intervention. There was positive correlation between receptivity among group members and openness, communication, understanding, friendliness and satisfaction. There was positive correlation between openness, communication, friendliness and satisfaction, and group atmosphere. Based on the above findings, I realize that MBTI basic program is essential to the improvement of group cohesion. In addition, it is shown that the sub-factors of interpersonal relation such as openness, communication, friendliness, satisfaction, and understanding, and the sub-factors such as group intervention and receptivity among group members are major factors to improve interpersonal relationship and group cohesion. So, the future MBTI program should include sub-programs that deal with the above factors to improve interpersonal relationship and group cohesion.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.21-33
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• 2008

In this study, the researcher examined archaeomagnetic secular variation of Chungcheong Region through measured data of archaeomagnet obtained from 34 relics, which discovered in the baked earth from varied historic sites within the region. Furthermore, the researcher closely reviewed regional differences of geomagnetic field in the domestic territory. Reviewing the comparison between the measured data of archaeomagnet in Chungcheong Region and the archaeomagnetic secular variation of Japan, which has difference in distance, it reveals a noticeable change in declination by tilting more than 10 degree toward East in the year of about A.D. 300, although the feature of whole variation is quite similar. In other period of times, it was confirmed that the regional differences of geomagnetic field in which the magnetic dip became deeper to some degree, and the declination was tilted westward a little bit. Such patterns do not differ significantly from the pattern of entire archaeomagnetic secular variation of our country, and even in the direct comparison to the data of Chungcheong Region, the distinct regional difference in both periods before and after Christian era was not confirmed. The fact may become clearer that, when the volume of the measured data of archaeomagnet increases further, and when more data connected with varied time period are filled, the problem such as deviation of the measurement period of archaeomagnet caused by the regional difference of geomagnetic field would not be worrisome issue, especially in Korean territory, judging from the measured data of archaeomagnet of historic relics in Chungcheong Region. Besides, as great efforts are being exerted in order to get the most reliable measured data as much as possible in taking both samples and measurement, it is thought that there would be no problem not only in the issue of deviation of the measurement period involving with the measured data of archeomagnet, but also in the aspect of reliability of data.

• Journal of Information Display
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• v.13 no.2
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• pp.73-82
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• 2012

In this paper, a light-emitting diode (LED) backlight driver integrated circuit (IC) for medium-sized liquid crystal displays (LCDs) is proposed. In the proposed IC, a linear current regulator with matched internal resistors and an adaptive phase-shifted pulse-width modulation (PWM) dimming controller are also proposed to improve LED current uniformity and reliability. The double feedback loop control boost converter is used to achieve high power efficiency, fast transient characteristic, and high dimming frequency and resolution. The proposed IC was fabricated using the 0.35 ${\mu}m$ bipolar-CMOS-DMOS (BCD) process. The LED current uniformity and LED fault immunity of the proposed IC were verified through experiments. The measured power efficiency was 90%; the measured LED current uniformity, 97%; and the measured rising and falling times of the LED current, 86 and 7 ns, respectively. Due to the fast rising and falling characteristics, the proposed IC operates up to 39 kHz PWM dimming frequency, with an 8-bit dimming resolution. It was verified that the phase difference between the PWM dimming signals is changed adaptively when LED fault occurs. The experiment results showed that the proposed IC meets the requirements for the LED backlight driver IC for medium-sized LCDs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.2
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• pp.140-145
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• 2013

This paper proposes the high speed LDPC decoder structure base on the DVB-S2. Firstly, We study the solution to avoid the memory conflict. For the high speed decoding process the decoder adapts the HSS(Horizontal Shuffle Scheduling) scheme. Secondly, for the high speed decoding algorithm normalized Min-Sum algorithm is adapted instead of Sum-Product algorithm. And the self corrected is a variant of the LDPC decoding that sets the reliability of a Mc${\rightarrow}$v message to 0 if there is an inconsistency between the signs of the current incoming messages Mv'${\rightarrow}$c and the sign of the previous incoming messages Moldv'${\rightarrow}$c This self-corrected algorithm avoids the propagation on unreliable information in the Tanner graph and thus, helps the convergence of the decoder.Start after striking space key 2 times. Lastly, and this paper propose the optimal hardware architecture supporting the high speed throughput.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.15-29
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• 2014

Increasing the smart instrument based social and economical activity, problems of electronic business's safety, reliability and user's privacy are be on the rise. so variety standard cryptography algorithms for information security have been developed in korea and How to efficiently implement them in a variety of environments is issued. ARIA and SEED, developed in Korea, are standard block cipher algorithm to encrypt the 128-bit plaintext, are each configured Feistel, SPN structure. In this paper, SEED and ARIA were implemented using the GEZEL language that can be used easily in the software designer because grammar is simple compared to other hardware description language. In particular, in this paper, will be described in detail the characteristics and design method using GEZEL as the first paper that implements 128bits ARIA and SEED and it showed the flexibility and efficiency of development using GEZEL. SEED designed GEZEL is occupied 69043 slice, is operating Maximum frequency 146.25Mhz and ARIA is occupied 7282 slice, is operating Maximum frequency 286.172Mhz. Also, Speed of SEED designed and implemented signal flow method is improved 296%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4549-4567
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• 2016

To cope with the complex electromagnetic environment of wireless communication systems, anti-jamming decision methods are necessary to keep the reliability of communication. Basing on the rule-reduced genetic algorithm (RRGA), an anti-jamming decision method is proposed in this paper to adapt to the fast channel variations. Firstly, the reduced decision rules are obtained according to the rough set (RS) theory. Secondly, the randomly generated initial population of the genetic algorithm (GA) is screened and the individuals are preserved in accordance with the reduced decision rules. Finally, the initial population after screening is utilized in the genetic algorithm to optimize the communication parameters. In order to remove the dependency on the weights, this paper deploys an anti-jamming decision objective function, which aims at maximizing the normalized transmission rate under the constraints of minimizing the normalized transmitting power with the pre-defined bit error rate (BER). Simulations are carried out to verify the performance of both the traditional genetic algorithm and the adaptive genetic algorithm. Simulation results show that the convergence rates of the two algorithms increase significantly thanks to the initial population determined by the reduced-rules, without losing the accuracy of the decision-making. Meanwhile, the weight-independent objective function makes the algorithm more practical than the traditional methods.

• Journal of Broadcast Engineering
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• v.16 no.6
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• pp.977-985
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• 2011

Recent works on multiuser transmission techniques have shown that the linear growth of capacity in single user MIMO system can be translated to the multiuser MIMO scenario as well. In this paper, we propose a method pursuing performance gain of vector perturbation in multiuser downlink systems. Instead of employing maximum number of mobile users for communication, we use small part of them as virtual users for improving reliability of users participating communication. By controlling parameters of virtual users including information and perturbation vector, we obtain considerable improvement in the effective SNR, resulting in large gain in bit error rate performance. Simulation results on the realistic multiuser downlink systems show that the proposed method brings substantial performance gain over the standard vector perturbation with marginal overhead in computations.