• Journal of Biosystems Engineering
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• v.12 no.2
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• pp.44-59
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• 1987

The objectives of this study were to analyze and develop the model systems of rice post-harvest systems from drying to processing, and to develop a bulk system among them which requires minimum system cost and less operating time. The significance of this study was the development of a computer program (PPSARR). The PPSARR makes it possible to evaluate quantitatively the performance and economics of the rice post-harvest systems. The results show that the rice post-harvest bulk system requires less time and cost such as 37-60% and 46-59% of those of the sack system, respectively. Also, the former requires less manpower than the latter. For not more than 1,800 ton of rough rice production, the bulk system which is "drying & storage by IBDS-transport-milling" is recommended, and for more than 1,800 ton, the one which is "drying & storage by IBDS - transport - storing at flat storage improved - transport - processing by RPC" is recommended.

• Journal of the Korean Society for Precision Engineering
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• v.1 no.2
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• pp.33-40
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• 1984

Chatter is a relative vibration between workpiece and tool in machining of metals, and is an important limiting factor of production rate and surface quality, and also reduces the life of machine-tool itself and its tool. In this study, in order to suppress the machining chatter, the spring and the rubber damper are adopted to the tool post of a lathe. The results obtained in this experimental study are summarized as follows. 1. The spring and the damper employed in the tool post for the suppression of chatter increase the maximum chatter-free depth of cut and optimum values found for spring constant and compressive strain are 95kg/mm, 0.1954 respectively. 2. On the optimum condition resulting in this experimental study, the modified tool post increased 6 times in the maximum chatter-free depth of cut as compared with the conventional tool post.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.98-105
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• 2014

According to a simple survey on the current status of the assembly line design, it was found that trial and error methods on the basis of experiences have been used mainly in domestic manufacturing industries, even though there exist a lot of excellent line balancing studies. It seems that more practical researches should be carried out to develop user-oriented line balancing tools especially for small and medium-sized enterprises. This study presents a design of the line balancing tool which can support the line balancing tasks of nonspecialists. The proposed design tool is composed of three major modules: pre-process, line balancing, and post-process. In particular, pre-process and post-process are newly proposed to increase its ease of use. We applied the proposed design to a test problem and test result showed that our practical method may contribute to enhance the efficiency of production operations management.

• Electronics and Telecommunications Trends
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• v.38 no.6
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• pp.128-136
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• 2023

Lithium accounts for only 0.0017% of the earth crust, and it is produced in geographically limited regions such as South America, the United States, and China. Since the first half of 2017, the price of lithium has been continuously increasing, and with the rapid adoption of electric vehicles, lithium resources are expected to be depleted in the near future. In addition, economic blocs worldwide face intensifying scenarios such as competition for technological supremacy and protectionism of domestic industries. Consequently, Korea is deepening its dependence on China for core materials and is vulnerable to the influence of the United States Inflation Reduction Act. We analyze post-lithium secondary battery technologies that rely on more earth-abundant elements to replace lithium, whose production is limited to specific regions. Specifically, we focus on the technological status and issues of sodium-ion, zinc-air, and redox-flow batteries. In addition, research trends in post-lithium secondary batteries are examined. Post-lithium secondary batteries seem promising for large-capacity energy storage systems while reducing the costs of raw materials compared with existing lithium-based technologies.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.31-38
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• 2013

This study investigated the influence of English vowel pronunciation training to English word-initial stop pronunciation. For that purpose, VOT values of English stops produced by twenty Korean English learners(five Youngnam dialect male speakers, five Youngnam dialect female speakers, five Kangwon dialect male speakers, and five Kangwon dialect female speakers) were measured using the Speech Analyzer and their post-training production was compared with their pre-training production. The result shows that post-training VOT values of voiced stops became closer to those of native English speakers in all four groups. Hence, it can be inferred that vowel pronunciation training is effective for correcting pronunciation of voiced vowels by analyzing the change of the quality of following vowels(especially low vowels) and the degree of giving stress.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.175-178
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• 2004

본 연구는 디지털 합성(Composition)에 있어 포스트 프로덕션에서 해야될 작업 중 분리 렌더 시스템(Separating System)을 이용한 효과적인 합성 연구에 관한 것이다. 분리 렌더는 결과적으로 제작상의 시간과 경비를 절감시켜 줄 뿐만 아니라, 제작의 퀄리티(Quality)에 직접적으로 영향을 주기 때문에 이팩츠 합성(Effects Composition)이나 특수영상 제작에 있어 없어서는 안될 중요한 부분이다. 이 분리 렌더 시스템을 이용해서 현재 진행되는 작업상의 문제를 최소화 시킬 수 있다. 또한 영상효과 제작이나 특수영상 제작중에 발생 되어지는 여러 가지 복잡한 문제점(합성)들을 이를 통해 줄여줄 뿐만 아니라, 영상합성 단계에 있어 효과적인 디지털 영상과 렌더 테이터 관리를 동시에 만들어 주기 때문이다. 이러한 방법적 연구와 결과치의 자료들을 데이터화 한다면 디지털영상 산업계에 많은 이점을 줄 것으로 기대한다.

• Broadcasting and Media Magazine
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• v.4 no.4
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• pp.46-51
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• 1999

The introduction of broadcast digital television (DTV) was, at one time, seen as an opportunity to rationalise video formats. The reality is quite different with a rapid divergence as the united States' ATSC offers 18 formats to cover both standard definition (SD) and high definition (HD), and yet more are supported by Europe's DVB. At the same time multi-media is expanding both as an area for source material and for finished work. Post production needs to move away from single-format facilities as requirements for multi-format operation is already increasing. A 'format-independent' solution is described which allows efficient operation with any mix of input formats and able to output any format with high quality. Attention is given to retaining the speed, accuracy and immediacy which is a feature of today's professional facilities -even while handling the greater demands of HD. Another route, using 24 frames-per-second is also examined.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.542-551
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• 2015

The purpose of this study is to examine how Korean college students perceive and produce American English vowels /i, ɪ, eɪ, ${\varepsilon}$, ${\ae}$, ${\alpha}$, ɔ, oʊ, ʊ, u, ʌ/ embedded in CVC words, and further to examine the relationship between perception and production of the target vowels. Forty-two participants who are English major/double major were divided into 2 groups under different conditions: the control group took only theoretical lessons about English phonetics and the experimental group took 4-week phonetic training lessons in addition to the theoretical ones. The result of the pretest revealed that the two groups showed strong correlations between perception and production. However in the post-test, both of the two groups had no correlation between the two elements. The two groups showed changes in the correct percentage in the post-test and this had the influence on the correlations between perception and production. The control group showed the fluctuation in perception, whereas the experimental group showed improvement in production, and these changes in the post-test had an influence on the correlations between perception and production. Based on this analysis, pedagogical implications were discussed and limitations of the study were also described.

• Journal of The Korean Association of Information Education
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• v.20 no.1
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• pp.29-38
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• 2016

This study selected and utilized the 'Naver post' as an e-book production tool to be used for learning. The production of such SNS format e-books aimed at founding out its effect on learning attitude and academic achievement by stimulating interest and confidence in the learning of the students. To accomplish such an aim, the study selected 50 students from two classes in the fourth grade of a public elementary school. One class of 25 students went through a social studies lesson that applied SNS type e-book production activities, and the other class of 25 students underwent a regular social studies lesson as the comparative group. The major results of the study's analysis is SNS type e-book production did not significantly improve academic achievement in social studies, but SNS type e-book production significantly improved the learning attitude during social studies.

• Biomedical Science Letters
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• v.23 no.2
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• pp.111-117
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• 2017

Leukocytes in blood components are involved in diverse adverse transfusion reactions such as febrile non-hemolytic transfusion reactions. Therefore, leukocyte reduction is required to reduce these adverse reactions. The objective of this study was to compare the efficiency of pre-storage filtration and post-storage filtration. Filtration time, residual leukocyte count, RBC recovery, and hemolysis were assessed after pre-storage or post-storage filtration. Compared to pre-storage filtration, filtration time was prolonged and hemolysis was dramatically increased when post-storage filtration was performed. Residual leukocytes count and RBC recovery after post-storage filtration were similar with those obtained after pre-storage filtration. These results suggest that pre-storage filtration has better efficiency than post-storage filtration. These are thought to contribute to the production of better quality of leukoreduction blood components.