• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.678-683
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• 2016

The study aim was to investigate a comparison of muscle activity fatigue between maximal and submaximal strength gains during the bench press in men. It was hypothesized that maximal voluntary contraction (%MVC) would similar gains between maximal and submaximal strength gains during the bench press, but median frequency (MDF) would increase in maximal compared with submaximal exercise. Employing a randomized, counterbalanced crossover design, 12 men were asked to perform maximal repetitions and submaximal repetitions (concentric: 1-s, eccentric: 1-s, 2-s/repetition) to failure with a load of 85% of 1RM for the bench press, with a 3-minute recovery between the sets. Each subject was tested for the number of repetitions and sets, total work in bench press. Surface electromyography (EMG) was recorded from the pectoralis major, deltoid anterior, and triceps brachii for %MVC and MDF. Total work was significantly higher in the submaximal repetition exercise than that the maximal repetition exercise (p<.05). Muscle fatigue of pectoralis major, deltoid anterior and triceps brachii were significantly smaller in the submaximnal repetition exercise than that the maximal repetition exercise (p<.05, respectively). However, muscle activity of pectoralis major, deltoid anterior, and triceps brachii were not significantly different between exercises. Our study showed that a smaller muscle fatigue in submaximal repetitions, despite higher in total work and a similar in muscle activity were observed. These results suggest that submaximal repetitions during the bench press would be enhanced intensity and/or volume compared with maximal repetitions exercise.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.3
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• pp.19-26
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• 2008

We propose a selective detection scheme based on pulse repetition considering the BER (Bit Error Rate) performance and complexity of coherent IR-UWB (Impulse Radio-Ultra Wide Band) systems. To take system complexity into account, the proposed scheme transmits the UWB signals by pulse repetition at the transmitter, like conventional PRC (Pulse Repetition Coding). However, to effectively improve BER performance of the system, the proposed scheme performs selective detection by estimating the SNR (Signal-to-Noise Ratio) of the received pulse-repeated signal at the UWB receiver. Hence, the proposed scheme effectively improves BER performance of the coherent IR-UWB systems without increasing system complexity, as compared to the conventional PRC algorithm.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.603-625
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• 2010

Neural representation of a visual object is distributed across visual cortex and overlapped with those of many other objects. Thus repeating an object facilitates the recognition of the object while it impairs the recognition of other objects. These effects are called repetition priming and antipriming, respectively. Two experiments investigated a new phenomenon of repetition antipriming, in which a repeated object itself is antiprimed. The learning stage presented object pictures which were degraded at various levels. Participants determined how recognizable each object was. Then, the test stage presented the intact version of the object pictures and made participants to perform a categorization task. Both Experiment 1 and 2 found that the processing of the objects that had been recognized were facilitated (repetition priming) while the processing of the objects that had been perceptually ambiguous were impaired (repetition antipriming). These findings suggest that experiencing a perceptually ambiguous object might enhance the connection between feature-level representations and multiple object-level representations, which impairs the subsequent recognition of the repeated object.

• Journal of Astronomy and Space Sciences
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• v.32 no.3
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• pp.209-219
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• 2015

The Accurate Ranging System for Geodetic Observation - Mobile (ARGO-M) was successfully developed as the first Korean mobile Satellite Laser Ranging (SLR) system in 2012, and has joined in the International Laser Ranging Service (ILRS) tracking network, DAEdeoK (DAEK) station. The DAEK SLR station was approved as a validated station in April 2014, through the ILRS station "data validation" process. The ARGO-M system is designed to enable 2 kHz laser ranging with millimeter-level precision for geodetic, remote sensing, navigation, and experimental satellites equipped with Laser Retro-reflector Arrays (LRAs). In this paper, we present the design and development of a next generation high-repetition-rate SLR system for ARGO-M. The laser ranging rate up to 10 kHz is becoming an important issue in the SLR community to improve ranging precision. To implement high-repetition-rate SLR system, the High-repetition-rate SLR operation system (HSLR-10) was designed and developed using ARGO-M Range Gate Generator (A-RGG), so as to enable laser ranging from 50 Hz to 10 kHz. HSLR-10 includes both hardware controlling software and data post-processing software. This paper shows the design and development of key technologies of high-repetition-rate SLR system. The developed system was tested successfully at DAEK station and then moved to Sejong station, a new Korean SLR station, on July 1, 2015. HSLR-10 will begin normal operations at Sejong station in the near future.

• Journal of Educational Research in Mathematics
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• v.24 no.1
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• pp.67-82
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• 2014

The term "objectification" has various definitions or perspectives. Nevertheless, it's pursued commonly by groups from various perspectives who emphasize the activities of becoming aware of a process as a totality, realizing that transformations can act on that totality, that is, turning processes into object. The purpose of this study is to identify how students objectify the concept of repetition regarding permutation and combination and find difficulties of objectification focusing on teacher's and students' discourse from common emphasis on previous researches associated with objectification. Students objectified the concept of repetition by replacing talk about processes with talk about objects regarding repetition and using discursive forms that presented phenomena in an impersonal way. The difficulties of objectification were derived from close linkage between the way of using keywords regarding repetition and everyday language.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.371-372
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• 2010

• Phonetics and Speech Sciences
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• v.12 no.1
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• pp.85-95
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• 2020

Sentence repetition is a way of evaluating speech sound production to improve the limitation of word tests and spontaneous speech analysis. Speech sounds produced by children can be evaluated using several indicators. This study examined the progression of the percentage of correct consonants-revised (PCC-R) and phonological whole-word measure in different age and gender groups after setting consonants in various vowel contexts and implementing sentence repetition tasks that were designed to give all phonemes the chance to appear at least three times. For this study, 11 sentence repetition tasks were applied to 535 children aged 3 to 7 across the country, after which the resulting PCC-R and whole-word measure were analyzed. The study results showed that all the indicators improved in older age groups and there were significant differences depending on age, however, no significant differences dependent on gender were found. The sentence repetition conditions data used in this study were collected from across the country, and the age difference between each age group was six months. This study is noteworthy because it collected a sufficient amount of data from each group, highlighted the limitation of the word naming and the spontaneous speech analysis, and suggests new criteria of evaluation through the analysis of each whole-word measure in sentence repetition, which was not applied in previous studies.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.85-91
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• 2016

Typically, radar systems change the pulse repetition interval of their modulated signal in order to avoid detection. On the other hand the radar-signal detection system tries to detect the modulation pattern. The histogram or auto-correlation methods are usually used to detect the PRI pattern of the radar signal. However these methods tend to lost the sequence information of the PRI pulses. This paper proposes a PRI-sequence detection algorithm based on the finite-state machine that could detect not only the PRI pattern but also their sequence.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.514-517
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• 1996

Zero current switching(ZCS) series resonant converter is used to control laser power density in a pulsed Nd:YAG laser power supply. The high power and high repetition rate paused Nd:YAG laser is designed and fabricated to control current pulse width and pulse repetition rate in the double elliptical laser oscillator. In order to find out operational characteristics of pulsed Nd:YAG laser, the electrical properties of driving power supply and laser output power are investigated and experimented by changing of the current pulse width from 200uS to 350uS(step 50uS) and pulse repetition rate range of 500pps(pulse per second) to 1150pps. From that result, we obtaind maximum efficiency of 1.83% and maximum laser output or 220W at the condition of 350 uS and 1150pps with one Nd:YAG rod), and obtained that of more than 400W with two laser head connecting series.

• Journal of Korea Water Resources Association
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• v.44 no.9
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• pp.731-740
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• 2011

An acoustic velocity profiler is developed, which is able to be used for open-channel flow measurement. It measures flow velocity based Doppler effect on acoustic signals, which is estimated by using pulse repetition frequency technique. Laboratory and field tests were made to verify velocity measuring performance of the developed device. It is confirmed that the acoustic velocity profiler can normally measure vertical velocity profile in the range above 0.1 m from the bottom and has equivalent performance to commercial acoustic velocity measuring devices.