• Electronics and Telecommunications Trends
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• v.34 no.4
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• pp.65-75
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• 2019

Sensory substitution involves mapping the characteristics of one sensory modality to the stimuli of another sensory modality. In general, when a person is visually impaired or deaf, they do not actually lose their ability to see or hear completely; however, they only lose their ability to transmit sensory signals from the periphery to the brain. It has been experimentally proven that a person who has lost the ability to retrieve data from the retina can still visualize subjective images by using data transferred from other sensory modalities such as tactile or auditory modalities. This is because vision processing pathways are still intact in most cases. Therefore, sensory substitution uses human perception and the plasticity of the human brain to transmit sensory signals through pathways that have not been lost. In this study, we analyze the characteristics and problems of various devices used for sensory substitution and summarize the recent technological trends in these devices.

• Journal of Life Science
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• v.11 no.4
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• pp.346-353
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• 2001

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) a prototype of the highly toxid halogenated arylhydrocarbons, bioaccumulates in the food chain and induces a complex spectrum of pathological responses. However, its effect on the nerve system is relatively not well studied. In this study we evaluated TCDDs cytotoxicity on the cortical cell and investigated its effect on the expression 2,3-cyclic nucleotide 3-phosphodiesterase(CNPase), a marker for oilgodendrocytes, The survival rates of 4 DIV cortical cells, that are dissociated from E18 rat cortex and maintained in the presence of TCDD, were 88.8, 83.6, 78.5, and 78.6%(5,10, 20 and 50 nM, respectively) where the reduction in 20 and 50mM TCDD were statistically very significant(p<0.01). Imunocytochemistry of cultured cells revealed that the intensities of immunostaining with an anti-CNP1&2 antibody depended on the concentrations of the toxin. Immunoblot analysis also showed differential expression of CNP1 and CNP2 in the presence of TCDD; the CNP1 expression was dose-dependently decreased. Interestingly, the expression of CNP2 in the presence if TDCC; the CNP1 expression was dose-dependently decreased. Interestingly, the expression of CNP2 fluctuated with the TCDD concentration. These results indicated that CNP1 and 2 are differentially regulated by TCDD, implying the functions of oligodendrocytes are modulated by the toxin.

• Journal of KIISE:Software and Applications
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• v.29 no.11
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• pp.837-850
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• 2002

In this paper, we propose an EEG-based response time prediction method during a yes/no cognitive decision task. In the experimental task, a subject goes through responding of visual stimulus, understanding the given problem, controlling hand motions, and hitting a key. Considering the subject's varying brain activities, we model subjects' mental states with defining CT (cut time), ST (selection time), and RP (repeated period). Based on the assumption between ST and RT in the mental model, we predict subjects' response time by detection of selection time. To recognize the subjects' selection time ST, we extract 3 types of feature from the filtered brain waves at frequency bands of $\alpha$, $\beta$, ${\gamma}$ waves in 4 electrode pairs combined by spatial relationships. From the extracted features, we construct specific rules for each subject and meta rules including common factors in all subjects. Applying the ST detection rules to 8 subjects gives 83% success rates and also shows that the subjects will hit a key in 0.73 seconds after ST detected. To validate the detection rules and parameters, we test the rules for 2 subjects among 8 and discuss about the experimental results. We expect that the proposed detection method can be a basic technology for brain-computer-interface by combining with left/right hand movement or yes/no discrimination methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.4
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• pp.1-9
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• 2009

In this paper, a small area 12-bit 300MSPS CMOS Digital-to-Analog Converter(DAC) is proposed for display systems. The architecture of the DAC is based on a current steering 6+6 segmented type, which reduces non-linearity error and other secondary effects. In order to improve the linearity and glitch noise, an analog current cell using monitoring bias circuit is designed. For the purpose of reducing chip area and power dissipation, furthermore, a noble self-clocked switching logic is proposed. To verify the performance, it is fabricated with $0.13{\mu}m$ thick-gate 1-poly 6-metal N-well Samsung CMOS technology. The effective chip area is $0.26mm^2$ ($510{\mu}m{\times}510{\mu}m$) with 100mW power consumption. The measured INL (Integrated Non Linearity) and DNL (Differential Non Linearity) are within ${\pm}3LSB$ and ${\pm}1LSB$, respectively. The measured SFDR is about 70dB, when the input frequency is 15MHz at 300MHz clock frequency.

• Journal of Technologic Dentistry
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• v.32 no.4
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• pp.341-350
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• 2010

Purpose: This study focused on achieving desired shades by combining zirconia core with different thickness porcelain in order to make dental prostheses effectively. Methods: White and colored $LAVA^{TM}$ All Ceramic (3M-ESPE, Seefeld, Germany), and Zirkonzahn (Bruneck, Italy) Trans and prettau were used to have Zirconia. LAVATM Ceram (3M-ESPE, Germany) and ICE (Zirkonzahn, Italy) powder were used to have the porcelain. We made quadrilateral specimen of thickness 0.3mm, 0.5mm, 0.7mm and diameter 10 to use zirconia ceramics system of 2 kinds that color tone reappearance way is different and produced total 120 specimens to 4 experimental groups. We used Spectrophotometer to analyze color tone. Data's value getting by dispersal colorimetry period found L*, a*, b* value using Excel program. We used one-way ANOVA to use SPSS WIN 12.0 program. Results: All L*, a*, b* indexes of zirconia core and porcelain veneer in LAVA group and Zirkonzahn group were different. When you combine the white zirconia core of LAVA group with a porcelain veneer, the thickness of the porcelain must be more than 0.5mm to meet the standard target. When all the colored zirconia cores of LAVA group were combined with porcelain veneers, there was no significant difference from the standard target. When the zirconia cores of Zirkonzahn group are combined with porcelain veneers, the thinner thicknesses were closer to the standard tab than thicker thicknesses; however, there was a significant difference in all combinations, with Delta E* value indicating more than 3. Conclusion: When it comes to colored zirconia, which is the most popular, the thicknesses of both a core and a dentin veneer must be more than 0.3mm to get an appropriate shade. There is more possibility to get desirable shades when the thicknesses of a white core are thinner; however, they would be vulnerable to the environment and lose their color. When combine a zirconia core with a dentin veneer, using Zirkonzahn group needs more considerations in order to meet the standard target.

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.145-150
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• 2004

Two experiments were conducted to evaluate the nutritional values of rice bran and to examine effects of its dietary supplementation on broiler performances. In the first experiment, true metabolizable energy(TME), nitrogen corrected true metabolizable energy(TMEn), and true amino acid availability(TAAA) values of the rice bran were determined by force-feeding sixteen roosters(ISA-Brown). In the second experiment, 3-week-old male broiler chickens(Avian) were divided into four groups and fed each one of four experimental diets containing 0, 5, 10 or 15% rice bran for 21 days. TME and TMEn values of the rice bran(dry matter basis) were 3.25 kcal/g and 3.12 kcal/g, respectively, and the average TAAA value of the 16 amino acids was 76.21%. The average feed intake and body weight gain of the birds fed diets containing rice bran were apparently greater than those of the control group although the differences were not significant statistically. From the results, it can be concluded that feed formulation using bioavailability values, such as TMEn and TAAA, is an effective method for protecting the high variation in growth performances and that rice bran can be used for broiler feeds to 15% without any significant negative effects.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.168-178
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• 2012

The objective of this study is applied to office buildings to evaluate quantitative evaluation method about performance of double-skin at design stage to establish the basis for the purpose of evaluation performance. Select the evaluation building about design plan for applying the double-skin using the dynamic heat load analysis program the annual heating and cooling load of before and after the double-skin. Using CFD to analyze wind factor and applied ventilation for realistic results. Effects of double-skin to apply, and control techniques that can be done more realistically proposed through to set and control for shade control mode of ventilator and inside cavity wall of double-skin. Apply for the building the double-skin due to interpretation of the annual heating and cooling loads applied to interpret the quantitative effect confirmed the possibility. According to the form of a double skin was confirmed cavity environmental changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.91-99
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• 2019

Naval Ships have a number of requirements related to performance. Naval ship acquisition takes a long time from initial planning to delivery, and various products such as drawings and reports are created. In complex systems, such as naval ships, it is difficult to maintain the required traceability through these outputs. The basic design of the ship is an important step to determine the specifications, performance, and equipment of the ship. It is necessary to apply the systematic requirements management process. The basic design manages the requirements in accordance with the systems engineering-based technical review process, but the actual system architecture design process is not presented. The traceability between the requirements and the functional and physical architectures of components is unclear. This paper examined how to design the system architecture required for specification and system design, and the design results were verified using SE-based technical review process for requirements management. A step-by-step process for designing a submarine system architecture is presented and verified using the SE technical review. This facilitates the specification of the requirements and system architecture design, and supports traceability management and verification of the requirements. The proposed process can be applied in various ships including submarines.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.96-104
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• 2018

Military vessels are complex weapon systems consisting of various integrated onboard equipment. Since their acquisition of military equipment takes a long period of time and a prototype ship is deployed and tested, vessel development has relied on its proprietary process. However, due to the growing complexity of onboard equipment technology, application of systems engineering (SE) process has become indispensable. Nonetheless, an effective design process complementing the existing design with the SE has not yet been developed. As such, we have studied an improved basic design process for submarines based on SE. To do so, we analyzed the processes for the basic design, technical review, and requirement management. Included reviews and requirements are SRR, SFR and PDR, and SSRS, SSS, and SSDD. By combining the results in the SE framework, we built an improved basic design process that can be applied in parallel with the SE-based technical review and requirement management. To assess the process, we applied our proposed model to the submarine development undergoing the basic design phase. It is possible to effectively manage the requirements, design artifacts and improve traceability, and also utilize them as test and evaluation materials. The SE-based basic design process is expected to be useful in other kinds of vessel design.

• Journal of Climate Change Research
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• v.5 no.2
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• pp.179-187
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• 2014

The global warming caused by GHG has emerged as a global environmental problem. For this reason the continued efforts to reduce GHG emission by international cooperation and each country are in progress. This study was performed for a successful accomplishment of Korea's ETS aims in 2015, that is to reduce GHG emission, maintain competitiveness of the domestic industries and to reinforce competitiveness of the environmental management of domestic companies through comparing analysis research of major overseas ETSs with main features of Korea's ETS and the analysis of semiconductor industry. In this study, the cases of already being implemented ETS countries such as the European Union, the United States and New Zealand etc. have been investigated by comparing to Korea's ETS. We also suggested the detailed political proposals to stabilize the introduction of Korea's ETS at the enterprise level.