• Journal of the Korean Society of Industry Convergence
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• v.13 no.2
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• pp.99-106
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• 2010

The effects of additive and shrinkage reducing agent on the drying and autogenous shrinkage of high strength concrete are investigated in this study. As results, when the ratio of W/B(low water to binder ratio) increase, the compressive strength is decreased. Comparing with PC(portland cement) concrete, the strength is 2.8%, 3.2% and 3.8% lower respectively than that of PC when concrete mixing ratio is 0.2%, 0.3% and 0.4% in 28 days curing. Drying shrinkage strain of PC concrete showed $-650{\times}10^{-6}$ in 91 days curing. When SR(shrinkage reducing agent) of 0.2%, 0.3% and 0.4% is mixed, the drying shrinkage strains are 21%, 34% and 41% lower than those of PC in 91 days curing. Autogenous shrinkage strain of PC concrete appeared $-480{\times}10^{-6}$ in 56 days curing. When SR of 0.2%, 0.3% and 0.4% is mixed, the autogenous drying shrinkage strain are 12.5%, 19.8% and 33.3% lower than those of PC in 56 days curing. In cases of using the mineral and shrinkage agent or only using a shrinkage reducing agent also appeared same reducing effects for drying shrinkage and autogenous shrinkage.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.591-596
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• 2019

In this paper, we implemented a deep learning operation structure with less influence of local PC performance. In general, the deep learning model has a large amount of computation and is heavily influenced by the performance of the processing PC. In this paper, we implemented deep learning operation using AWS and streaming server to reduce this limitation. First, deep learning operations were performed on AWS so that deep learning operation would work even if the performance of the local PC decreased. However, with AWS, the output is less real-time relative to the input when computed. Second, we use streaming server to increase the real-time of deep learning model. If the streaming server is not used, the real-time performance is poor because the images must be processed one by one or by stacking the images. We used the YOLO v3 model as a deep learning model for performance comparison experiments, and compared the performance of local PCs with instances of AWS and GTX1080, a high-performance GPU. The simulation results show that the test time per image is 0.023444 seconds when using the p3 instance of AWS, which is similar to the test time per image of 0.027099 seconds on a local PC with the high-performance GPU GTX1080.

• Journal of Music and Human Behavior
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• v.12 no.1
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• pp.1-21
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• 2015

This study examined the effects of a tablet PC-based music-making program on the executive function of adolescents with intellectual disabilities. Four adolescents with intellectual disabilities participated in this program. Each participant received 45-minute individual sessions twice a week for a total of 16 sessions. The music-making program was designed in the sequence of planning; learning table PC operations; exploring musical elements; making rhythm, melody, and lyrics; composing loop sections; and presentation of the completed music. The Stroop test, Children's Color Trails Test, and Digit Span and Letter-Number sequencing tests were measured at pretest, midtest, and posttest in order to examine changes in executive function. The participants showed increased scores on all three tests. The participants' attention span also increased and their attempts to correct errors during tasks occurred more frequently at posttest. This study supports the effects of the technology-based program on the executive function of adolescents with intellectual disabilities and presents its expanded applicability for adolescents who show low cognitive function and limited motivation for cognitive engagement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1841-1854
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• 1993

In this paper, the packet voice protocol for the transmission of voice signal onto ethernet is implemented in a personal computer (PC). The packet voice protocol used is a modified one from CCITT G.764 packetized voice protocol. The hardware system to facilitate the voice communication onto ethernet is divided into telephone interface, speech processing, PC interface and controllers. The software structure of the protocol is designed according to the OSI seven layer architecture and is divided into three routines : ethernet device driver, telephone interface, and processing routine of the packet voice protocol. Experiments through ethernet with telephone interface show that this packet voice communication achieves satisfactory quality when the network traffic is light.

• Molecules and Cells
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• v.37 no.12
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• pp.841-850
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• 2014

Polycomb group (PcG) proteins are conserved chromatin regulators involved in the control of key developmental programs in eukaryotes. They collectively provide the transcriptional memory unique to each cell identity by maintaining transcriptional states of developmental genes. PcG proteins form multi-protein complexes, known as Polycomb repressive complex 1 (PRC1) and Polycomb repressive complex 2 (PRC2). PRC1 and PRC2 contribute to the stable gene silencing in part through catalyzing covalent histone modifications. Components of PRC1 and PRC2 are well conserved from plants to animals. PcG-mediated gene silencing has been extensively investigated in efforts to understand molecular mechanisms underlying developmental programs in eukaryotes. Here, we describe our current knowledge on PcG-mediated gene repression which dictates developmental programs by dynamic layers of regulatory activities, with an emphasis given to the model plant Arabidopsis thaliana.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.59.1-59.1
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• 2011

BSF 후면전계효과는 태양전지의 개방전압 증가를 결정하며 효율에 매우 중요한 요인이다. 본 연구에서는 p-type에서의 후면전계효과를 확인하기 위해 PC1D 시뮬레이션(Simulation)을 통해 p+ 영역의 표면농도와 깊이에 따른 전기적 특성을 분석 하였다. 최적효율을 찾기위해 면저항을 $30{\Omega}/{\square}$으로 고정하고 깊이와 표면 농도값을 가변하였다. 최적화 결과 표면농도값이 작아지고 깊이가 커질수록 효율이 좋아지는 경향이 나타났으며 Peak doping=$5{\times}10^{18}cm^{-3}$, Juction depth=12.52um에서 최고효율 19.14%를 얻을 수 있었다. 본 시뮬레이션을 바탕으로 실제 태양전지 제작 과정에 적용 가능하다. p-type 태양전지 제작에서 후면의 p+ 영역의 깊이를 증가시키고, 표면 농도를 낮추는 공정을 통해 효율향상을 기대 할 수 있다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.140-145
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• 1997

A stuey to investigate the perception characteristics of color and brightness was conducted in a combined PC and TV monitor, The objective of this study is to suggest user's favorite color temperature in PC mode and user's favorite contrast in TV mode. Investigated factors were monitor coating(coatiog vs. non-coation)and screen brightness (30fL vs. 35fL)in first experiment and monitor coating and pucture movement(static vs. dynamic) in second experiment. The first experiment was conducted in TV mode. Twenty-three subjects (male 12, female 11) perticipated in this experiment. In first experiment, average color temperatures were about 8000K in all experimental conditions. In addition, there was significant difference between coating and non-coating screen at 0.1 level. In second experiment, average contrasts were obtained in all esperimental conditions. There was significant difference between coating and ndn-coating screen at 0.05 level, In addition, there was significant difference between static picture and dynamic picture at 0.1 level

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.333-338
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• 1997

We performed a study to investigate the characteristics of color perception according to some factors and to suggest the initial setting value of color temperature in each mode of a PC and TV monitor. Investigated factors were monitor coating (coating vs. noncoating)and screen brightness(30fL vs. 35fL). Twenty-three subjects (male 12, female 11) participated in this experiment. The experiment was performed in eachmode of a PC and TV monitor. Average color temperatures were obtained in both PC- mode and TV- mode. In addition, effects of monitor coating and screen brightness were investigated.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.99-105
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• 1996

Increasing demands on precision machining of free-form surfaces have necessitated the tool to move not only with position error as small as possible, but also with smoothly varying feedrates. In this paper, linear, circular and spline interpolators were developed in reference-pulse type using PC. M-SAM and M-DAM were designed by the comparison and analysis of previous interpolation methods. Spline interpolator was designed to follow the free-form curves. To apply to the real cutting process, constant feedrate compensation and acceleration-deceleration compensation were conceived. Finally, its performance was tested using retrofitted milling machine. As a result, new interpolation algorithm is favorable in precision machining of free-form curves.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.157-163
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• 2008

Formation of ${\beta}$-amyloid $(A{\beta})$ fibrils has been identified as one of the major characteristics of Alzheimer's disease (AD). Inhibition of $A{\beta}$ fibril formation in the CNS would be attractive therapeutic targets for the treatment of AD. Several small compounds that inhibit amyloid formation or amyloid neurotoxicity in vitro have been known. Citrate has surfactant function effect because of its molecular structure having high anionic charge density, in addition to the well-known antibacterial and antioxidant properties. Therefore, we hypothesized that citrate might have the inhibitory effect against $A{\beta}$ fibril formation in vitro and have the protective effect against $A{\beta}$-induced neurotoxicity in PC12 cells. We examined the effect of citrate against the formation of $A{\beta}$ fibrils by measuring the intensity of fluorescence in thioflavin-T (Th-T) assay of between $A{\beta}_{25-35}$ groups treated with citrate and the control with $A{\beta}_{25-35}$ alone. The neuroprotective effect of citrate against $A{\beta}$-induced toxicity in PC12 cells was investigated using the WST-1 assay. Fluorescence spectroscopy showed that citrate inhibited dose-dependently the formation of $A{\beta}$ fibrils from ${\beta}$-amyloid peptides. The inhibition percentages of $A{\beta}$ fibril formation by citrate (1, 2.5, and 5 mM) were 31%, 60%, and 68% at 7 days, respectively in thioflavin-T (Th-T) assay. WST-1 assay revealed that the toxic effect of $A{\beta}_{25-35}$ was reduced, in a dose-dependent manner to citrate. The percentages of neuroprotection by citrate (1, 2.5, and 5 mM) against $A{\beta}-induced$ toxicity were 19%, 31 %, and 34%, respectively. We report that citrate inhibits the formation of $A{\beta}$ fibrils in vitro and has neuroprotective effect against $A{\beta}$-induced toxicity in PC12 cells. Neuroprotective effects of citrate against $A{\beta}$ might be, to some extent, attributable to its inhibition of $A{\beta}$ fibril formation. Although the mechanism of anti-amyloidogenic activity is not clear, the possible mechanism is that citrate might have two effects, salting-in and surfactant effects. These results suggest that citrate could be of potential therapeutic value in Alzheimer's disease.