• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.169-180
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• 2018

White light-emitting diodes (LEDs) are more economical than fluorescent lights, and provide high brightness, a high lifetime expectancy, and greater durability. As LEDs are closely connected with people's daily lives, dimming control of LED is an important component in providing energy savings and improving quality of life. In visible light communications systems using these LEDs, multiple input multiple output (MIMO) technology has attracted a lot of attention, in that it can attain the channel capacity in proportion to the number of antennas. This paper analyzes the power performance of three kinds of modulation in visible light communications (VLC) systems applied space-time block code (STBC) techniques. The modulation schemes are return-to-zero on-off keying (RZ-OOK), variable pulse position modulation (VPPM), and overlapping pulse position modulation (OPPM), and dimming control was applied. The power requirements and power consumption were used as metrics to compare the power efficiency in $2{\times}2$ STBC-VLC environments under the three kinds of modulation. We confirm that dimming control affects the communications performance of each modulation scheme. VPPM showed greater consumption among the three modulations, and OPPM showed energy savings comparable to VPPM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.455-464
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• 2018

This study investigated whether the whitening effects of fullerene serum occurred through improvement of melanin production and skin tone and evaluated its potential for use as a cosmetic material for adult women aged 30-55 with dull skin color and pigmentation. Subjects were divided into a control group with fullerene-less serum (B) and an experimental group with serum containing 0.1% fullerene (A) and evaluated over 8 weeks. Visual assessment and measurement of skin conditions (melanin index, skin brightness) were conducted before use of and 4 and 8 weeks after use of the product, and a questionnaire survey and safety assessment were conducted at the end of the experiment. The results revealed that the highest decrease was 0.37% in the experimental group (A) after eight weeks of use of the product, but that this difference was not statistically significant. Moreover, no significant differences were observed upon inter-group comparison. Evaluation of changes in the melanin index and inter-group comparison revealed a significant decline in the experimental group (A) at all time points. Additionally, the $L^*$ value (skin brightness) of the experimental group (A) showed a significant increase (improvement) after eight weeks, while in inter-group comparison revealed a significant increase (improvement) at all time points (4 and 8 weeks later) (p<0.05). Based on a questionnaire survey of efficacy, positive response rates such as improvement of the target parts on week 8 were high in terms of 'improvement of skin color.' Moreover, the safety assessment revealed no adverse reactions. In conclusion, serum containing 0.1% fullerene revealed improved melanin production and skin tone (brightness) and confirmed its potential for use as a cosmetic material with brightening efficacy. Taken together, the results of this study indicate systematic investigation of the effective application and cosmetics formulations of this product are warranted.

• Electrical & Electronic Materials
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• v.12 no.7
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• pp.7-11
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• 1999

Fully sealed field emission display in size of 4.5 inch has been fabricated using single-wall carbon nanotubes-organic vehicle com-posite. The fabricated display were fully scalable at low temperature below 415$^{\circ}C$ and CNTs were vertically aligned using paste squeeze and surface rubbing techniques. The turn-on fields of 1V/${\mu}{\textrm}{m}$ and field emis-sion current of 1.5mA at 3V/${\mu}{\textrm}{m}$ (J=90${\mu}{\textrm}{m}$/$\textrm{cm}^2$)were observed. Brightness of 1800cd/$m^2$ at 3.7V/${\mu}{\textrm}{m}$ was observed on the entire area of 4.5-inch panel from the green phosphor-ITO glass. The fluctuation of the current was found to be about 7% over a 4.5-inch cath-ode area. This reliable result enables us to produce large area full-color flat panel dis-play in the near future. Carbon nanotubes (CNTs) have attracted much attention because of their unique elec-trical properties and their potential applica-tions [1, 2]. Large aspect ratio of CNTs together with high chemical stability. ther-mal conductivity, and high mechanical strength are advantageous for applications to the field emitter [3]. Several results have been reported on the field emissions from multi-walled nanotubes (MWNTs) and single-walled nanotubes (SWNTs) grown from arc discharge [4, 5]. De Heer et al. have reported the field emission from nan-otubes aligned by the suspension-filtering method. This approach is too difficult to be fully adopted in integration process. Recently, there have been efforts to make applications to field emission devices using nanotubes. Saito et al. demonstrated a car-bon nanotube-based lamp, which was oper-ated at high voltage (10KV) [8]. Aproto-type diode structure was tested by the size of 100mm $\times$ 10mm in vacuum chamber [9]. the difficulties arise from the arrangement of vertically aligned nanotubes after the growth. Recently vertically aligned carbon nanotubes have been synthesized using plasma-enhanced chemical vapor deposition(CVD) [6, 7]. Yet, control of a large area synthesis is still not easily accessible with such approaches. Here we report integra-tion processes of fully sealed 4.5-inch CNT-field emission displays (FEDs). Low turn-on voltage with high brightness, and stabili-ty clearly demonstrate the potential applica-bility of carbon nanotubes to full color dis-plays in near future. For flat panel display in a large area, car-bon nanotubes-based field emitters were fabricated by using nanotubes-organic vehi-cles. The purified SWNTs, which were syn-thesized by dc arc discharge, were dispersed in iso propyl alcohol, and then mixed with on organic binder. The paste of well-dis-persed carbon nanotubes was squeezed onto the metal-patterned sodalime glass throuhg the metal mesh of 20${\mu}{\textrm}{m}$ in size and subse-quently heat-treated in order to remove the organic binder. The insulating spacers in thickness of 200${\mu}{\textrm}{m}$ are inserted between the lower and upper glasses. The Y\ulcornerO\ulcornerS:Eu, ZnS:Cu, Al, and ZnS:Ag, Cl, phosphors are electrically deposited on the upper glass for red, green, and blue colors, respectively. The typical sizes of each phosphor are 2~3 micron. The assembled structure was sealed in an atmosphere of highly purified Ar gas by means of a glass frit. The display plate was evacuated down to the pressure level of 1$\times$10\ulcorner Torr. Three non-evaporable getters of Ti-Zr-V-Fe were activated during the final heat-exhausting procedure. Finally, the active area of 4.5-inch panel with fully sealed carbon nanotubes was pro-duced. Emission currents were character-ized by the DC-mode and pulse-modulating mode at the voltage up to 800 volts. The brightness of field emission was measured by the Luminance calorimeter (BM-7, Topcon).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.319-327
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• 2020

Particulate matters (PM) are small particulate pollution that decrease the function of skin barrier, which causes inflammatory skin diseases and extrinsic aging. In this study, we evaluated the effect of preventing the adherence of PMs from several cosmetic products applied to human skin using iron oxide black. The PM floating chamber consists of skin exposure area, PM inlet, floating power device, and an outlet so that PM can be naturally attached to the skin while floating in the chamber. The change in skin brightness according to the floating concentration of alternative fine dust was checked to confirm the optimal floating concentration conditions. The intensity difference (before-after intensity, Δ) before and after adhesion of iron oxide black was proportional to the amount of PM adhered. The anti-adherence effect of iron oxide black on five cosmetic products were evaluated through 20 each subjects by comparing the amount of iron oxide black adhered on the control and treatment. The difference in brightness before and after the iron oxide black attached to the skin was calculated and compared with the control group(p < 0.05). When over 150 mg of iron oxide black was adhered on the skin, the interference of intensity was low and clearly showed the skin adhered pattern. According to the application of the five cosmetics, the intensity difference was significantly lower than the control group. This means that depending on the product, it prevented the attachment of iron oxide black. This study is a safe and useful method to confirm the prevention of PM skin adherence. In conclusion, cosmetics can prevent the adherence of PM on the skin according to the formulation or ingredients characteristics.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.765-771
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• 2015

This study was performed to examine the quality characteristics and antioxidant activity of the curd yogurt with different contents (0.5-2%, w/w) of acanthopanax powder (AP). The pH decreased with increasing AP content until 16 h, whereas the treated groups showed higher pH levels than the control group after 20 h. The viscosity and the viable cell counts of the yogurt with 2% AP were lower than those of the control group during fermentation, significantly. Color values of AP yogurt were lower in terms of brightness, whereas redness and yellowness values were higher compared to the control group. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and soluble content significantly increased with increasing AP content. Consumer acceptability score of yogurt with 0.5% AP was ranked higher than other yogurts. Yogurt added with 0.5% AP showed no differences in pH, titrable acidity, and viable cell counts compared to the control group after storage at $4^{\circ}C$ for 14 days.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1006-1013
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• 2014

This study is aimed at examining the usefulness of mugwort as an alternative of western herb by making widely known tomato sauce with mugwort powder added, the ingredient that has a bio-active substance. The control group showed the highest percentage of water from tomato sauce, 89.24%. The sauce with mugwort added in by 2% showed the lowest pH, 4.55. The brightness L value for chromaticity got lower significantly (p>0.001) as the amount of added mugwort increased, and red a value and yellow b value were high in the control group for 18.06 and 16.84 respectively, and got reduced as the amount of added mugwort increased. The salinity was the highest in the sauce mugwort added in by 2% for 1.02. Sugar content and reducing sugar were the lowest in the sauce mugwort added in by 2% for 9.49 and 56.01. As measuring total count change, no microorganism was found until $10^{th}$ day of storage, and was 0% $1.7{\times}10^3CFU/mL$ on the $15^{th}$ day, and no microorganism was found in the 1.5% and 2% added groups. Lastly for 60 days of storage, the control group without mugwort showed the highest microorganism count for $3.1{\times}10^8CFU/mL$ In a sensory test, color was in the 1% added group was 5.28, higher than the control group which showed 4.78, but there was no significant difference. Taste was rated most highly in the 1.5% added group for 5.65. After taste was also rated most highly in the 1.5% added group for 5.8. Overall preference was the highest in the 1% added group for 5.79. From the results, tomato sauce with mugwort added in showed the high storage capacity and was rated highly in the preference test. The possibility of the alternative of western spice and the potential to use Korean spice for other western spice were observed again.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.625-631
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• 2017

This study was performed to examine the quality characteristics and antioxidant activity of curd yogurt with varying content (0.5-2% (w/w)) of lemon grass hot-water extract (LGHWE). The pH decreased with higher LGHWE content until 8 h, with the treated groups showing higher pH values than the control group after 12 h. The viscosity and the viable cell counts of the yogurt with 2% LGHWE were significantly lower than those of the control group during fermentation. Color values of LGHWE yogurt were lower in terms of brightness, whereas redness and yellowness values were higher compared to the control. The DPPH radical scavenging activity and soluble content significantly increased with higher LGHWE content. Consumer acceptability score of yogurt with 0.5% LGHWE was ranked higher than that of other yogurts. Yogurt containing 0.5% LGHWE showed no differences in pH and titratable acidity compared to control after storage at $4^{\circ}C$ for 14 days.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.432-437
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• 2017

Yellow sticky traps have been commonly used for monitoring tobacco whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect tobacco whitefly capture. Therefore, the use of light-emitting traps can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out in tomato greenhouses to evaluate the light-emitting trap as potential attractants for Bemisia tabaci adults. The results showed that B. tabaci adults on average preferred (p>0.05) traps in yellow lights (590 nm) ($168{\pm}7.6adults/trap$) compared to traps in white lights ($106{\pm}4.6adults/trap$) and traps without lights ($60{\pm}4.8adults/trap$). The yellow light trap(590 nm) showed the most attractive to B. tabaci adults, followed by a little lower attraction to the white light trap(450-625 nm), whereas the control (no light trap) was little attractive to B. tabaci adults. These results suggested that yellow and white light traps could have a promising use in greenhouses for the identification, monitoring, and pest control tools of tobacco whiteflies.

• Journal of Technologic Dentistry
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• v.25 no.1
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• pp.41-62
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• 2003

In this research, we manufactured the paste opaque porcelains using Propylene Glycol (PG) and Buthylene Glycol (BG) as a solvent, and compared the composition of solvents, the coefficient of thermal expansion, the particle size distribution, the viscosity and bonding strength to metal, and the tone with those of the commercial products(Duceram Plus, Duceram GmbH; VMK 95, Vita Co.; Noritake EX-3, Noritake Co.)used in the clinical field. The results of the research were as follows: 1. The result of solvent analysis indicated that the solvents included in the paste opaque porcelains of the control group were mainly composed of Glycols. 2. From the Coefficient of thermal expansion measurement, we drew out the following results; testing group: $14.0\times10^{-6}/^{\circ}C$, Duceram Plus: $13.9\times10^{-6}/^{\circ}C$, VMK 95: $14.3\times10^{-6}/^{\circ}C$, and Noritake EX-3: $13.3\times10^{-6}/^{\circ}C$. 3. Seen from the result of particle size distribution measurement, the experimental group was similar to the control group in 1$\mu m$ below, but the experimental group marked the highest distribution of 61% in the case of between 1$\mu m$ and 5$\mu m$. Between 5$\mu m$ and 10$\mu m$, they showed relatively similar distribution, and Noritake EX-3 was turned out the highest distribution of 29% in 10$\mu m$ above. 4. From the result of viscosity measurement, Duceram plus showed the highest viscosity throughout all the measurements followed by Noritake Ex-3, experimental group and VMK 95 in decreasing order. 5. The result of bonding strength measurement was EX 35.53 $\beta\acute{A}$, DU 40.88 $\beta\acute{A}$, VM 39.43 $\beta\acute{A}$, and NO 35.39 $\beta\acute{A}$, and no significant difference was found between the experimental group and the control groups(P>0.05). 6. The measurement of the tone indicated that the $L^*$ value of the experimental group was 86.89 0.63 in average, which is higher than the control group in its brightness. In the case of the $a^*$ value, Duceram Plus, VMK 95 and EX-3 showed positive value, whereas the testing group was turned out negative value. In $b^*$ value, Duceram Plus proved the highest. From the results of this research, the paste opaque porcelains using Propylene Glycol (PG) and Buthylene Glycol (BG) as a solvent did not make differences from the commercial products that are actually used in the clinical fields. Therefore, it is possible to utilize Propylene Glycol (PG) and Buthylene Glycol (BG) for the paste opaque porcelains of P.F.M crown. It is also recommended that further researches concerning the compositions and forms of powder, the types of organic solvent components and the ratio of mixture proceeded in order to improve the level of productivity in the future.

• Food Science and Preservation
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• v.19 no.4
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• pp.510-518
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• 2012

In this research, to modernize traditional food and to make functional bokryung-byung, bokryung-byungwas made with Poriacocos Wolf powder added. During its storage, its moisture content ranged from 42.89 to 44.85%. The control group had the highes tmoisture content (44.85%), and it was reduced significantly as the Poriacocos Wolf powder in creased. The longer the storage period was, the lower the pH and the higher the acidity was. The total bacterial count increased from 2.70 to 3.00 Log CFU/g right after the manufacture and increased rapidly on the fourth day of the storage with more than 7.00 Log CFU/g. There was no difference between the control group and the bokryung-byung, though. The Hunter's color value after the manufacture, with the increase in the added Poriacocos Wolf powder, showed a significantly reduced brightness, but significantly increased redness and yellowness. Their chromaticity did not change, how ever, during their storageat a temperature of $20^{\circ}C$. The hardness, solidity, gumminess, and cohesiveness of the bokryung-byung increased, unlike in the control group, and its brittleness increased. In terms of the overall preference, the preference for the control group was high, but was higher when 5 % Poria cocos Wolf powder was added during the manufacture of the bokryung-byung. As a result of these correlations, it is believed that elastic and chewy dduks are preferred and bokryung-byungs could be developed as functional dduks.