• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.291-299
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• 2018

PURPOSE. To assess the degree of conversion (DC) and light irradiance delivered to light-cured and dual-cured cements by application of different light sources through various types of monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) materials. MATERIALS AND METHODS. RelyX Ultimate Clicker light-cured and dual-cured resin cement specimens with 1.5-mm thicknesses (n=300, 10/group), were placed under four types of crystalline core structure (Vita Enamic, Vita Suprinity, GC Ceresmart, Degudent Prettau Anterior). The specimens were irradiated for 40 seconds with an LED Soft-Start or pulse-delay unit or 20 seconds with a QTH unit. DC ratios were determined by using Fourier transform infrared spectroscopy (FTIR) after curing the specimen at 1 day and 1 month. The data were analyzed using the Mann-Whitney U test (for paired comparison) and the Kruskal-Wallis H test (for multiple comparison), with a significance level of P<.05. RESULTS. DC values were the highest for RelyX Ultimate Clicker light-cure specimens polymerized with the LED Soft-Start unit. The combination of the Vita Suprinity disc and RelyX Ultimate Clicker dual-cure resin cement yielded significantly higher values at both timepoints with all light units (all, P<.05). CONCLUSION. Within the limitations of this study, we conclude that the DC of RelyX Ultimate Clicker dual-cure resin cement was improved significantly by the use of Vita Suprinity and the LED Soft-Start light unit. We strongly recommend the combined use of an LED light unit and dual-cure luting cement for monolithic ceramic restorations.

• Proceedings of the KACD Conference
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• 2002.11a
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• pp.675-675
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• 2002

No Abstract, See Full Text

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.117-130
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• 2008

This paper proposes a stable and robust method to distinct the color similarity for clothes using the LBG algorithm under various light sources, Since the conventional methods, such as the histogram intersection and the accumulated histogram, are profoundly sensitive to the changing of light environments, the distinction of color similarity for the same cloth can be different due to the complicated light sources. To reduce the effects of the light sources, the properties of hue and saturation which consistently sustain the characteristic of the color under the various changes of light sources are analyzed to define the characteristic of the color distribution. In a two-dimensional space determined by the properties of hue and saturation, the LBG algorithm, a non-parametric clustering approach, is applied to examine the color distribution of images for each clothes. The color similarity of images is defined by the average of Euclidean distance between the mapping clusters which are calculated from the result of clustering of both images. To prove the stability of the proposed method, the results of the color similarity between our method and the traditional histogram analysis based methods are compared using a dozen of cloth examples that obtained under different light environments. Our method successively provides the classification between the same cloth image pair and the different cloth image pair and this classification of color similarity for clothe images obtains the 91.6% of success rate.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.49-54
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• 2013

In this study, I was focusing on LED (Light Emitting Diode) light effect in growth of chrysanthemum. For this reason, I formed six monochromatic lights (red 650 nm, 647 nm, 622 nm, blue 463 nm, 450 nm, white), six mixed lights sources red : blue (9 : 1, 8 : 2, 7 : 3, 6 : 4, 5 : 5) and 3 control beds in light sources ratio between rad : blue (8 : 2) including sun light. It was totally 15 control beds. Depending on light investigation time in growth, 6/6 (on/off) was highest in the length of plant, the number of leaves, the fresh dry and leaf area. But statistical significance wasn't accepted in general. In case of monochromatic lights, length of plant and leaf area is biggest in the Blue 450 mm and the length of root is highest in RED 650 mm. Except for this 3 measuring points (length of plant, the number of leaves and fresh weight), sun light and white was highest. Besides there are monochromatic light effect but various wavelength range in light sources are needed to crop growth. In terms of mixed light resources, except for sun light, It turned out the length of plant is highest in the highest red light rate red : blue (9 : 1), and Red : white (7 : 3) is highest in fresh weight and dry weight. The sun light is the highest one in the leaf area. The results from LED light effect in growth of chrysanthemum are obviously effect on growth and building up the shape. We need to choose suitable light sources in the monochromatic lights and mixed lights for growing high quality of chrysanthemum or Supplemental Lighting.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.76-88
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• 2010

Recently, LED background image devices are used for the production of broadcasting programs. But the effective advantages of LED background image devices are not realized for good HD video quality because the correlations between lighting sources and LED background image devices are not analyzed yet. In this paper, we analyze the color change and light intensity that lighting sources and the light intensity ratio of LED background images influence on a subject, making use of equipments used in real broadcasting, and examine the correlations between HD video quality and the light intensity ratio of LED background images. As a result in this experiment, the video is most expressed having an 20[IRE] effect on a subject when the light intensity of LED background image is 6%. When the LED background image is light, the light and darkness of video is distorted and when the LED background image is dark, the colors of image are distorted.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.17-17
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• 1998

Synchrotron radiation is produced when charged particles moving with relativistic velocities a are accelerated - for example, deflected by the bending magnets which guide the electron or p positrons in circular accelerators or storage rings. By using special focusing magnetic lattices i in the particle accelerators it is possible to make the dimensions of the particle beam very small with a hi맹 charge density which results in a light source with high b디lIiance. Synchrotron light h has important properties which make it ideal for a wide range of investigations in surface s science. The fact that the spectrum of electromagnetic radiation emitted in a bending magnet e extends in a continuum from the 얹r infra red region to hard x-rays means that it is id않I for a v variety of spectroscopic studies. Since there are no convenient lasers, or other really bright l light sources, in the vacuum ultraviolet and soft x-ray re.밍ons the development of synchrotron r radiation has enabled enormous advances to be made in this di펌C비t spectr따 re밍on. P Polarization-dependent measurements, for ex없nple ellipsometry or circular dichroism studies a are possible because the radiation has a well-defined polarization - linear in the plane of orbit w with additional right-circular, or left-circular, components for emission an생es above, or below, t the horizontal, respectively. Since the synchrotron light is emitted from a bunch of charge c circulating in a ring the light is emitted with a well-defined time structure with a short flash of l light every time a bunch passes an exit port. The time structure depends on the size of the ring a and the number and sequence of filling of the bunches. A pulsed light source enables time¬r resolved studies to be performed which provide direct information on the lifetimes and decay m modes of excited states and in addition opens up the possibility of using time of flight t techniques for spectroscopic studies. The fact that synchrotron radiation is produced in a clean u ultrahi야 vacuum environment is of gr않t importance for surce science studies. The current t비rd generation synchrotron light sources provide exceptionally high baliance and stability a and open up possibilities for experiments which would have been inconceivable only a short time ago.

• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.57-69
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• 2013

Recently, an interest in functional foods has been increasing. It was recommended placing a short definition. Therefore, we performed research on the chemical functions and antioxidant ability of broccoli. This research is vital for preparing the most favorable conditions and environment for highly-functional broccoli. Broccoli produced after applying sprouting and light sources were used for research. The chemical properties of the broccoli, including composition, free sugar, citric acid, mineral and vitamin (A, C, E) content, were analyzed. In addition, the ability of broccoli compounds to reduce total phenolic compounds, SOD-liked activity, EDA (electron donating ability), and hydroxyl radicals were inspected. Total analysis relied on the SAS (statistical analysis system). Broccoli sprouts produced through plant factory system's photosynthesis, treated under different light sources, had superior amounts of crude protein, crude fat, and crude ash, compared to normal sprouts under fluorescent light. Is it a facility or does it refer to the inner metabolism of the cell? Broccoli sprouts under red light had superior amounts of glucose, fructose, malic acid, and oxalic acid, while broccoli sprouts under turquoise light had superior amounts of citric acid. Broccoli sprouts under white light had superior amounts of various minerals, such as potassium, magnesium, and sodium. In terms of antioxidant activity, data from the plant factory system shows an increase in EDA antioxidants (1.63 mg/mL, 30.82%). Sprouts applied with turquoise light had superior amounts of hydroxyl radical scavenging (65.62%), and sprouts applied with white light had superior amounts of activated SOD-like activity (52.69%). Research on dehydrated broccoli sprouts showed that sprouts dehydrated with cold air had superior amount of malic, citric, oxalic acid compared to sprouts dehydrated with hot air. In terms of vitamin levels, sprouts dehydrated with cold air had five times the normal amount of vitamin A and E, whereas sprouts dehydrated with hot air had higher amounts of vitamin C. Dehydration at low temperature also produced a higher amount of activated antioxidants (1.6 mg/mL of activated antioxidant ability, 63.04% of SOD-like activity, and 67.76% of hydroxyl radical scavenging). Our results show that antioxidant ability can vary by the type of photosynthesis and temperature level in which the sprouts are dehydrated. Therefore, thorough foundational data is required to product the most functional broccoli.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.14-22
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• 2011

The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.4
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• pp.46-54
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• 1994

Exhbitlon hghting design be done aftrr due consideration of the photochermcal reaction and h ~ ~ i i tc~.fficits~ upn exposure to light. In this study the balanced judgement is as follows. The most light-susceptible material shouid be illu~stratrui less than 50[k] (illurnlnance-hours per year : 120, 000k.h)and the illuminance of moderately sensitive rriatcrinl k 200[1x] (illuminance hours per year : 480, 0001x.h). Moreover to minimize damage the sources of light shoulcl not only contribute as little as heat possible but remove ultraviolt radiation by filters. Also the sources of light must have good color rendering and low color temperature.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.10
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• pp.491-498
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• 2001

We present a method of modeling lights from photographs taken with conventional imaging equipment. It does not use both any geometrical information and special apparatus to calculate surface reflection properties. To represent surface reflection properties of the scene, we use BRDFs which are calculated by radiance values of surface elements and light sources. And the BRDF data of each surface is further transformed to the spherical harmonic domain for efficient storage. Thus it allows to reconstruct the photo-realistic scene under different light sources, to manipulate diversely the arbitrary light source and to control exposure time of camera sensor. Moreover we test our algorithm with real image instead of synthetic image.