• Korean Journal of Child Studies
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• v.35 no.2
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• pp.157-169
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• 2014

This study sought to explore the types of predictable pattern books are suitable for reading aloud, the differences between English and translated Korean picture books in terms of their characteristics of speakability and the meaning of sentences. This study investigated a total of 112 picture books. The predictable pattern types were analyzed specifically, compared with onomatopoeia, mimetic words, repetition, rhyme, the shift of sentence and style types. The results indicated that predictable pattern books could be classified into eight types and the number of sentences in translated books increased owing to the difference of sentence structure. In terms of speakability, words in repetition, onomatopoeia and mimetic words represented higher frequency except rhyme because of the difference of characteristics of the two languages. Furthermore, translations used strategies of the shift in sentence and style types for speakability. These findings demonstrate that predictable pattern books can serve as good materials to read aloud for young children not only in terms of English picture books but also translated books regardless of concerns regarding their speakability.

• Journal of The Korean Association For Science Education
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• v.24 no.4
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• pp.731-747
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• 2004

The scientific inquiry enterprise consists of formulating hypotheses, testing hypotheses, evaluating evidence, and revising hypothesis. Scientific inquiry in the science classrooms requires students' background experience and knowledge with the phenomenon in order to ask appropriate questions, identify and define variables operationally, formulate hypotheses, and design clear and complete experiment. The ability to test hypotheses has been postulated to play a central role in cognitive processes. The purpose of this study was to analyze what the change of the quantity and quality of the hypothesis, the rejecting or accepting of the hypothesis, and the use results in the repetitional hypothesis activity experiments. To examine the problems, this study analyzed 5 classes which were designed and administered to 16 students of the 7th grade. The results of this study showed that students preferred the engineering method to scientific method and the quality of a second hypothesis got low. The quality of the hypothesis came to be higher through a repetitional hypothesis and the number of hypothesis was reduced. The results of the experiments did not play central roles in revising hypotheses and accepting or rejecting hypothesis.

• Journal of the Korean Society for Heat Treatment
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• v.7 no.2
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• pp.118-128
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• 1994

Five alloys were selected randomly in the composition range showing the best shape memory effect in Fe-Mn-Si system reported by Murakami. The shape memory effects of those alloys were mainly investigated through the training treatment which consisted of the repetition of 2% tensile deformation at room temperature and subsequent annealing at $600^{\circ}C$ above $A_r$ temperature. At the same deformation degress in rolling $600^{\circ}C$-annealing for 1 hr. showed the best shape memory effect, and 10%-deformation degrees represented maxima of the shpae memory effects at all annealing temperatures, $500^{\circ}C$, $600^{\circ}C$ and $700^{\circ}C$. The shape memory effects of the alloys were increased by increasing training cycle up to 5 cycles. This was because a large number of dislocations introduced by training process gave rise to increase in the austenite yield stress, and acted as nucleation sites for stress induced ${\varepsilon}$ martensite. The thermal cycling treatment, repetition of cooling in nitrogen at $-196{\circ}C$ and heating to $300^{\circ}C$ for 5 min., did not improve the shape memory effect.

• Physical Therapy Korea
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• v.2 no.1
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• pp.51-61
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• 1995

In general, research in isokinetic exercise has focussed on studies of peak torque. However, peak torque is not always sufficient to assess the real amount of motion or to determine endurance. In this study, the subjects were 54 healthy students who performed continuous maximal isokinetic knee flexion and extension until their total work per time reached 50% of their maximal total work. Isokinetic curves were then plotted. Total work sums, exercise durations in seconds, and the numbers of repetitions were compared with reference to subject gender, angular velocity and muscle group. The relationship between total work sum, duration and number of repetition and thigh circumference plus leg length was computed. In addition, the characteristics of total work per second and total work per time were calculated. Results showed the total work sums differed greatly from muscle group to muscle group and with different angular velocities. The duration in seconds and the numbers of repetition differed only at higher angular velocity. Males achieved higher levels in every category except for some duration in seconds and some numbers of repetitions. Thigh circumference and leg length were deciding fators in every case, but duration in seconds and number of repetitions were not. These results suggest that measures of endurance should be included along with measures of total work when isokinetic studies are done. Measures of endurance in seconds are more accurate when isokinetic exercise is performed at lower angular velocities and numbers of repetitions at higher angular velocities.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.31-38
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• 2020

Radar signal identification of electronic warfare is a technology that recognizes the pulse repetition interval (PRI) from a set of pulse description words (PDWs) generated by the signal receiver. Conventionally batch processing is widely used in which a number of PDWs are collected as a unit and identifies PRI from the batch. In this paper, we propose a feature extraction algorithm based on the streaming process. This technique does not wait to form a batch. Whenever a PDW(Pulse Description Word) is generated from the signal receiver, the streaming process tries to form a cluster of PDWs, and makes the DTOA (Difference of Time of Arrival) histogram, finds out the frame PRI based on the concentration ratio, and decides the number of stagger stages. Experiments proved that the proposed algorithm derives stable recognition results as the cluster size increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3C
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• pp.224-231
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• 2003

In this paper we proposed system parameter values of ultra-wideband Impulse Radio systems for the frequency band(3.1~10.6GHz), which is allocated by Federal Communications Commission(FCC). We also analyzed performance of the proposed system in the multiple access interference environment. According to result, application of possible pulse duration($t_{n}$) is very limited by 0.04~0.0326 ns in permission frequency range that establish in FCC. In the case of the same pulse signal power, we could know that system performance was changed by pulse repetition number($N_{s}$ ) regardless of pulse duration. Thus, We could know that we have to need duration of monocycle pulse and setting of frame un it time(Τ$_{f}$ ) according to multi user numbers and design proper pulse repetition number by transfer rate in multiple access systems design. In the IR system that needs high speed transmission more than 50 Mbps in multiple access interference environment, we could know that very serious performance decrease by multiple access interference happens. Therefore, as the design of high speed multiple access IR system, it should be designed to additional improvement techniques that can remove multiple access interference at the same time.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.623-630
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• 2012

Formation used as trackbed foundation for providing vertical bearing capacity onto rail foundation are composed of crushed stones usually with certain type of grain size distribution. Permanent deformation in trackbed foundation can be generated by increasing number of load repetition due to train traffic increases, causing track irregularity. In this study, a specially prepared trackbed foundation materials (M-40) used in Korea has been tested using a large repetitive triaxial compression apparatus in order to understand resilient and permanent deformation characteristics of the material. From these test results, resilient and permanent deformation characteristic are analyzed so that a permanent deformation model is developed which can consider number of load repetition N, confining stress (${\sigma}_3$), shear stress ratio(${\tau}/{\tau}_f$) and stiffness of the material.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.858-864
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• 2002

In this paper, Analyzed Performance of TH/UWB(Time Hopping/Ultra Wideband after Impulse Radio) system in interference environment by existing system that use same frequency band. In case interference fraction ratio is below 0.1, consider and analyzed in case influence through interference in IR system that is shared in 3.1 - 10.6 GHz band hereafter as case that use very small and narrow band than IR system such as 80 MHz bandwidth of ISM band or 802.1la's use bandwidth 20 MHz in 5 GHz band. According to result, we could know that Performance change according to possession band width of interference shows greatly than size of interference electric power. Also, interference fraction ratio is big (more than 0.1) narrowband interference in partial band interference environment, could get Performance improvement of big width increasing pulse repetition number. But, could know that do not influence hardly in system performance when interference fraction ratio is small (below 0.1) narrowband interference. Therefore, may receive the best system performance and transfer efficiency by set the most suitable pulse repetition number according to bandwidth fraction ratio of interference through correct interference fraction ratio estimation and apply proper interference suppression techniques.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1311-1319
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• 1992

In the partial-band interference and Rayleigh fading environments, the bit error probability equation of FH/MFSK signal has been derived and the error rate has been evaluated. And the results are shown in graphs and discussed. Here, to improve the error rate performance the repeated diversity and the error-correction coding techniques are adopted. The degree of improvement of error rate performance has been found out in diversity and coding techniques respectively. In diversity case, repetition number is taken as a parameter and in coding case, as the error-correction codes Hamming code, BCH code, and convolutional code are introduced. From the obtained results, we have known that the increase of the number of repetition in diversity technique has been brought a little improvement of performance but the coding technique considerable improvement and in particular, convolutional code is very effective. Therefore, coding technique is considered to be better than repeated diversity to cope with Rayleigh fading and partial-band interference.

• Journal of Science Education
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• v.46 no.1
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• pp.17-29
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• 2022

The purpose of this study is to look qualitatively into how efficiently and reasonably a computer can learn themes related to the Nature of Science (NOS). In this regard, a corpus has been constructed focusing on literature (920 abstracts) related to NOS, and factors of the optimized Word2Vec (CBOW, Skip-gram) were confirmed. According to the four dimensions (Inquiry, Thinking, Knowledge and STS) of NOS, the comparative evaluation on the word-level word embedding was conducted. As a result of the study, according to the previous studies and the pre-evaluation on performance, the CBOW model was determined to be 200 for the dimension, five for the number of threads, ten for the minimum frequency, 100 for the number of repetition and one for the context range. And the Skip-gram model was determined to be 200 for the number of dimension, five for the number of threads, ten for the minimum frequency, 200 for the number of repetition and three for the context range. The Skip-gram had better performance in the dimension of Inquiry in terms of types of words with high similarity by model, which was checked by applying it to the four dimensions of NOS. In the dimensions of Thinking and Knowledge, there was no difference in the embedding performance of both models, but in case of words with high similarity for each model, they are sharing the name of a reciprocal domain so it seems that it is required to apply other models additionally in order to learn properly. It was evaluated that the dimension of STS also had the embedding performance that was not sufficient to look into comprehensive STS elements, while listing words related to solution of problems excessively. It is expected that overall implications on models available for science education and utilization of artificial intelligence could be given by making a computer learn themes related to NOS through this study.