• New & Renewable Energy
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• v.16 no.3
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• pp.1-12
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• 2020

Shingled technology is the latest cell interconnection technology developed in the photovoltaic (PV) industry due to its reduced resistance loss, low-cost, and innovative electrically conductive adhesive (ECA). There are several advantages associated with shingled technology to develop cell to module (CTM) such as the module area enlargement, low processing temperature, and interconnection; these advantages further improves the energy yield capacity. This review paper provides valuable insight into CTM loss when cells are interconnected by shingled technology to form modules. The fill factor (FF) had improved, further reducing electrical power loss compared to the conventional module interconnection technology. The commercial PV module technology was mainly focused on different performance parameters; the module maximum power point (Pmpp), and module efficiency. The module was then subjected to anti-reflection (AR) coating and encapsulant material to absorb infrared (IR) and ultraviolet (UV) light, which can increase the overall efficiency of the shingled module by up to 24.4%. Module fabrication by shingled interconnection technology uses EGaIn paste; this enables further increases in output power under standard test conditions. Previous research has demonstrated that a total module output power of approximately 400 Wp may be achieved using shingled technology and CTM loss may be reduced to 0.03%, alongside the low cost of fabrication.

• Transactions on Electrical and Electronic Materials
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• v.5 no.3
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• pp.89-92
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• 2004

For improving solar efficiencies, down conversion of high-energy photons to visible lights is discussed. The losses due to thermalization of charge carriers generated by the absorption of high-energy photons, can largely be reduced in a solar cell if more than one electron-hole pair can be generated per incident photon. The solar cell was constructed of dye-sensitized anatase-based TiO$_2$, approximately 30nm particle size, 6$\mu\textrm{m}$thickness, and 6${\times}$6$\textrm{mm}^2$ active area, Pt counter electrode and I$_3$$\^$-/I$_2$$\^$-/ electrolyte. After correction for losses due to light reflection and absorption by the conducting glass, the conversion of photons to electric current is practically quantitative in the plateau region of the curves. The incident photon to current conversion efficiency(IPCE) of N3 used as a dye in this work is about 80% at around 590nm and 610nm which is the emission spectrum of Eu doped LGF. The Eu doped LGF powder was prepared by conventional ceramic process, and used as a down converter for DSC after spin coated on the slide glass and fired.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.195-198
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• 2012

The N basis functions are typically chosen so that Surface reflectance functions(SRFs) and spectral power distributions (SPDs) can be accurately reconstructed from their N-dimensional vector codes. Typical rendering applications assume that the resulting mapping is an isomorphism where vector operations of addition, scalar multiplication, component-wise multiplication on the N-vectors can be used to model physical operations such as superposition of lights, light-surface interactions and inter-reflection. The vector operations do not mirror the physical. However, if the choice of basis functions is restricted to characteristic functions then the resulting map between SPDs/SRFs and N-vectors is anisomorphism that preserves the physical operations needed in rendering. This paper will show how to select optimal characteristic function bases of any dimension N (number of basis functions) and also evaluate how accurately a large set of Munsell color chips can approximated as basis functions of dimension N.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.711-717
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• 2010

In this paper, a new automatic punching system that generates pinholes expressing texts or images on a plastic plate is developed. The pin-holed plate is used as a new glamorous display board reflecting colourful lights from the light emitting diode (LED) installed on the edge side of the plate. The punching system has four actuators which work together to make multiple holes with accurate position and depth on the plastic plate. For even reflection of the lights from texts or images on the board and fast production of the pin-holed boards, we developed an accurate actuating structure of the system cooperating with a PID control algorithm. We also built a GUI-based integrated control system to help users easily design luminous texts or images on the plastic plate. Also, we conducted a performance test of the system to verify the punching speed and depth control of the pin holes on the plastic plate.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.8-15
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• 2008

In this paper, in order to analyze property of frequency response in optical microphone, system was implemented. The capacitance microphone and fiber-optic transmission path type fiber-optic microphone (FOM) have weaknesses in directivity, size, weight, and price. However suggested optical microphone can be constituted by cheap devices, so it has many benefits like small size, light weight, high directivity, etc. Head part of optical microphone which is suggested in this paper is movable back and forth by sound pressure with the attached reflection plate. Operating point is determined by measuring the respond characteristics and choosing the point on which has maximum linearity and sensitivity while changing the distance between optical head and vibrating plate. We measured the output of the O/E transformed signal of the optical microphone while frequency of sound signal is changed using sound measurement/analysis program, Smaart Live and USBPre, which are based on PC, and compared the result from an existing capacitance microphone. The measured Optical microphone showed almost similar output characteristics as those of the compared condenser microphone, and its bandwidth performance was about 300[Hz]-3[kHz] at up to 3 [dB].

• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1474-1486
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• 2010

In this paper, we propose an algorithm which represents the distance depiction technique of real painting that named "Aerial Perspective" in painterly rendering. It is a painting technique that depicts the attenuations of light in the atmosphere, and the scattering effect is changed by the distance, altitude and density of atmospheres. For the reflection of these natures, we use the depth information corresponding to an input image and user-defined parameters, so that user changes the effect level. We calculate the distance and altitude of every pixel with the depth information and parameters about shot information, and control the scattering effects by expression parameters. Additionally, we accentuate the occluding edges detected by the depth information to clarify the sense of distance between fore and back-ground. We apply our algorithm on various landscape scenes, and generate the distance-emphasized results compared to existing works.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.577-585
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• 2010

This paper is a part of developing a software that predicts the infrared signal emitted from a ground object by considering solar irradiation. The radiance emitted from a surface can be calculated by using the temperature and optical characteristics of the surface object. The bidirectional reflectance distribution function (BRDF) is defined as the ratio of reflected radiance to incident irradiance. It is a very important surface reflection property that decides the reflected radiance from the object. In this paper, the spectral radiance received by a remote sensor over the mid-wave infrared(MWIR), and the long-wave infrared(LWIR) regions are computed and compared each other for several different materials. The results show that the optical surface properties such as the BRDF and the emissivity of the object surface can play a major role in generating the infrared signatures of various objects, and the largest infrared signal may reach up to 10 times the smallest one when the infrared signals obtained from a flat plate with different surface conditions under the sun light.

• Journal of Korea Game Society
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• v.7 no.4
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• pp.53-62
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• 2007

Although radiosity can represent diffuse reflections of the object surfaces by modeling energy exchange in 3D space, there are some restrictions for real-time applications because of its computation loads. Therefore, GPU(Graphics Processing Unit) based radiosity algorithms have been presented actively to improve its rendering performance. We implement the progressive refinement radiosity on GPU by G. Coombe in 3D scene that is constructed with HDR(High Dynamic Range) radiance map. This radiosity method can generate a photo-realistic rendering image in 3D space, where the synthetic objects were illuminated by the environmental light sources. In the simulation results, the rendering performance is analyzed according to the resolution of the texel in the environmental map and mipmaping. In addition, we compare the rendering results by our method with those by the incremental radiosity.

• Journal of the Korean Society of Costume
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• v.20
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• pp.125-135
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• 1993

The purposes of this research are firstly to define the characteristics of movement on the costume, secondly to demonstrate that fine art, expecially in relation to kinetic art, has become a good motif in modern costume de-sign, and thirdly to examin the characteristics of movement as shown in modern costume de-sign. For this study, we selected and analyzed some costume designs among those introduced in fashion magazines, which are Collections, Fashion-Preview, Fashion Show, Collezioni, and L'Officiel that have been issued since 1988. As this research is carried out only through the analysis of pictures, it is not ac-companied by a study on material itself. The result of this study is that the ex-pression of movement on modern fashion can be shown in two ways, one is the inclusive and subordinate movement expressed on the cloth-ing according to the motion of body when they are worn, and the other is the movement caused by the very designs of clothing. And the latter can be also divided in two ways, the illusionistic movement and the actual move-ment. The expression of actual movement is made through the emphasis of direction, rhythm, and dimension of the costume. And the illusionistic movement is expressed by the de-sign to which the textile pattern or reflection of light is applied so that the movement is larger than the actual movement. A sense of direction expressed on the cos-tume by the actual movement creates a light rhythm and adds interest to the costume. This reflects a part of psychology of modern men who are not accustomed to the statics. In the rapidly changing society of information our modern men seek after movement even in the statics. It is also true in the clothing and they seem to get a psychological rest through the immediated visual change as shown in fashion design. The simple and cheerful rhythm expressed by the illusionistic movement on the costume is attempted in order to overcome the static tediousness caused by simple design. These elements of movement cause the en-largement of visible range and create another enlarged shape other than the real one, so that they come to remove the dullness and monot-ony in costume design and provoke interest in costume, as if kinetic art reveals the various aspects that transcend the closed area of fine art upon the motif of 'movement'. finally, as this paper deals with the ex-pression of movement as shown in the costume design which prevailed after 1988, it is desir-able hereafter to study more about the fashion since 1950 when kinetic art began in earnest, along with the comparative study on the ex-pression of movement in our Korean designer's and foreign designer's works.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.358-373
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• 1997

Resin modified glass ionomers were introduced in 1988 to overcome the problems of moisture sensitivity and low early mechanical strength of conventional glass ionomers and to maintain their clinical advantages. The purpose of this study was to evaluate the color stability of four resin modified glass ionomers(Fuji II LC, Vitremer, Dyract and VariGlass), one resin composite material(Z-100), and one conventional glass ionomer(GC Fuji II) under several conditions. These conditions were as follows: 1) before curing, 2) after curing, 3) after polishing, 4) after 500 thermocycling, 5) after 1,000 thermocycling, 6) after 1,500 thermocycling and 7) after 2,000 thermocycling. Three specimens of each material/shade combination were made. Materials were condensed into metal mold with a diameter of 10 mm and a thickness of 2.0 mm, and were pressed between glass plates. The material was polymerized using a light polymerizing unit(Visilux II, 3M, USA). After removal of excess, the surface was polished sequentially on wet sandpapers. A reflection spectrophotometer(Model TC-6FX, Tokyo Denshoku Co., Japan) was used to determine CIELAB coordinates($L^*,a^*$ and $b^*$) of each specimen. CIE standard illumination C was used as the light source. The results were as follows : 1. In comparing different shades of same material, CIELAB color difference(${\Delta}E^*$) value was not significantly different from each other(p>0.05). 2. CIELAB color difference(${\Delta}E^*$) values between after-curing and after-polishing were ranged from 5.53 to 27.08. These values were higher than those of other condition combinations. 3. CIELAB color difference(${\Delta}E^*$) values between before-thermocycling and after-thermocycling were ranged from 1.40 to 7.81. Despite the number of thermocycling increased, CIELAB color difference(${\Delta}E^*$) value was low. 4. The color stability of resin modified glass ionomers was more stable than that of conventional glass ionomers but less stable than that of Z100.