• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.104-110
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• 2015

LED has added value as a lighting source in the illuminating industry because of its high efficiency and low power consumption. In LED production processes, the chip cutting process, which mainly uses a scribing process with a laser has an effect on quality and productivity of LED. This scribing process causes problems like heat deformation, decreasing strength. The inner laser method, which makes a void in wafer and induces self-cracking, can overcome these problems. In this paper, cutting sapphire wafer for fabricating LED chip using the inner laser scribing process is proposed and evaluated. The aim is to settle basic experiment conditions, determine parameters of cutting, and analyze the characteristics of cutting by means of experimentation.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.66-68
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• 2014

Most commercial white LED lamps use blue chip coated with yellow emitting phosphor. The use of blue excitable red and green phosphors is expected to improve the CRI. Several phosphors, such as $SrGa_2S_4:Eu^{2+}$ and $(Sr,Ba)SiO_4:Eu^{2+}$, have been suggested in the past as green components. However, there are issues of the sensitivity and stability of such phosphors. Here, we describe gallium substituted $YAG:Ce^{3+}$ phosphor, as a green emitter. YAG structures are already accepted by the industry, for their stability and efficiency. LEDs with improved CRI could be fabricated by choosing $Y_3Al_4GaO_{12}:Ce^{3+}$ (green and yellow), and $SrS:Eu^{2+}$ (red) phosphors, along with blue chip. Also, the effect of a slight change in chip wavelength is studied, for two phosphor-coated w-LEDs. The reduction in particle size of the coated phosphors also gives improved w-LED characteristics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1512-1516
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• 2018

The power system and control system constantly reveals surge voltage such as switching surge of lighting devices and power conversion devices, operating and stops surge of rotating devices, charge & discharge surge, opening & closing surge of circuit breakers and the like. Such a surge voltages can cause damage or malfunction of the element such as CPU, Memory, semiconductor etc. In the industry, in order to protect the system from the surge voltage, a surge protector with low discharge starting voltage, fast response time, and low capacitance is required, and technical development research for that is ongoing. In this paper, in order to solve the problem of the existing GDT discharge tube not discharging from the transient voltage which is higher than the commercial voltage and lower than the discharge voltage of the discharge element, we have developed a discharge element having the control electrode & control circuit. The discharge element having the control electrode and the control circuit can control the discharge voltage according to the needs of the consumer and can satisfy the requirement of the discharge element and the technology of the surge protector downsizing technology and the surge protection technology. It is judged to be effective for development.

• Journal of the Korea Computer Industry Society
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• v.3 no.12
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• pp.1765-1774
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• 2002

A face recognition is currently the field which many research have been processed actively. But many problems must be solved the previous problem. First, We must recognize the face of the object taking a location various lighting change and change of the camera into account. In this paper, we proposed that new method to fund feature within fast and correct computation time after scanning PC camera and ID card picture. It converted RGB color space to YUV. A face skin color extracts which equalize a histogram of Y ingredient without the luminance. After, the method use V' ingredient which transformes V ingredient of YUV and then find the face feature. The reult of the experiment shows getting correct input face image from ID Card picture and PC camera.

• Journal of the Korea Computer Industry Society
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• v.6 no.5
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• pp.741-748
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• 2005

Power saving module which is consisted of ferroelectric ceramic capacitor and time delay switching circuit was installed into electronic ballast in order to enhance energy efficacy and extend life time of fluorescent lamp. The impedance matching of negative resistance characteristics of F/L was optimized with the characteristics of ferroelectric ceramics capacitor to increase the light efficiency of the electronic ballast. The high efficiency of the electronic ballast was achieved by minimizing wasted power at the filament of F/L during the lighting by using the switching function of time delay circuit from preheating mode to non-preheating mode. The life time of F/L was also extended by eliminating the reverse electromotive force using time delay circuits to minimize the impacts to the filament of F/L from unwanted high voltage peaks during light-up period. As the results, the electronic ballast with the first grade energy efficiency was developed using ferroelectric ceramics and time delay module.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.114-119
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• 2011

There is a limit to technology of improving luminous intensity uniformity and glare, known as a weakness of existing LED lamp. Because of Using many LED, LED lamp not only waste energy but have bad effect on efficiency. Our goal is to develop security lights solution which is contented with suitable area in KS(Korean Industrial Standards) and to remove glare by combining asphere in optical system with different concept. To improve luminous intensity uniformity, a reflect mirror system was used after an aspheric optical system design for this study. We made a mirror and measured it after analysing luminance changes depend on aspheric shapes with simulation program to see if aspheric shapes effect luminance distribution. We made progress to find problems and improve them by comparing measured data and analysed data. This result of the study will contribute to industry of LED lighting through developing solution of emotional illumination of LED security lights by knowing the importance of reflectivity with this study and improving luminous intensity uniformity with solving the problem.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.81-85
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• 2011

Recently, the electronic parts are to be thinner plate, smaller size, light weight material and CPU, HDD and DRAM in all the parts have been produced on the basis of the high speed and greater capacity. Also, conventional goods have replaced a LED (Light-Emitting Diode) in lighting products so; such industry devices need to have cooling. To maximize all the performance on the heat-radiated products, the area of heat-radiated parts is required to be cooled for keeping the life time extension and performance of product up. Existing cooling systems are using radiant heat plate of aluminum, brass by extrusion molding, heat pipe or hydro-cooling system for cooling. There is a limitation for bringing the light weight of product, cost reduction, molding of the cooling system. So it is proposed that an alternative way was made for bringing to the cooling system. EP (Engineering Plastic) of low-cost ABS (Acrylonitrile butadiene styrene Resin) and PC (Polycarbonate) was coated with brass and the coating made the radiated heat go up. The performance of radiant heat plate is the similar to the existing part. We have studied experimentally on the radiated heat plate for the light-weight, molding improvement and low-cost. From now on, we are going to develop the way to replace the exiting plate with exterior surface of product as a cooling system.

• Korean Institute of Interior Design Journal
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• v.16 no.5
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• pp.81-88
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• 2007

Energy consumption has been increased world widely, and the energy retain is one of the most important economic alternatives. These tendencies expand the nuclear power plants not only quantitatively but also qualitatively. Despite of the increasing construction of nuclear power plants and related facilities, every system in main control room(MCR) has been designed and administered solely based on the safety-first principles because of the specificity of nuclear industry. However, recent main control rooms started with the concept that the operators' performance could be optimized though the organic interrelation between human, machine, and environments. Now, it has been recognised in the scope of Ergonomics and Space Design which acknowledge our living spaces as Man-Environment Interface and this change connotes the MCR spaces should be special spaces rather than ordinary spaces. This research investigated domestic and foreign nuclear power plants' MCRs to suggest basic alternatives which can be applied to future MCR. With the review of characteristics of MCR, an integration of interior design, lighting and Ergonomics was explored and classified as types. Futhermore, the classification of environmental characteristics within the relationships between human, machine, and environments was developed through the case analysis of nuclear power plants. The results of this study will provide a basis of space design for system environments that the high level of safety and function are extremely important.

• KIEAE Journal
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• v.3 no.4
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• pp.3-14
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• 2003

Remodeling for an aged building is emerging as a potential alternative towards the future of the building industry. It is a more effective method than the new construction in environmental friendly view. Most of remodeling were aimed at the improvement of the function of the deteriorated finishing materials. But, at the early stage of remodeling process, energy performance of a building can be improved by adopting passive design solutions such as daylighting and natural ventilation. The purpose of this study is to explain the passive design strategy in remodeling process and to suggest a application of LT method. LT method is an energy-design tool which responds to parameters available early in design development. It provides an output of annual primary energy for lighting, heating, cooling and ventilation in non-domestic buildings. LT method basically uses the concept of passive zone and non-passive zones and should be used to evaluate the energy performance of a number of options and to make comparisons. In this paper, the process of LT method is introduced and investigated an applicability in our office building.

• Archives of design research
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• v.16 no.1
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• pp.199-208
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• 2003

The Israel-born Ron Arad is one of Britain's "superstar" designers, an it has been said that he is Britain's answer to Philippe Starck. Arad is a highly individualistic designer whose ideas stem from a mental process that has more in common with that of the fine artist than of the jobbing designer for industry. His imagination expresses itself in the form of things. By the early 1990s he had become internationally recognized for his "ready-made" work. His furniture and lighting designs required extremely costly labour-intensive techniques to produce. As his work was highly evocative, suggesting a post-industrial world in which the urban landscape was characterized by materials in a state of decay. More recently, through collaborations with Italian and German manufactures, his work has reached a new level of sophistication and finish, which differentiates it from the earlier designs. As Arad reputation as a designer of workshop-based furniture came to an end and the era of "democratic" Arad furniture came into being. By middle of the decade he had become one of the most-discussed designers of the day. The spirituality that emanates from all his work is a product of his particular vision of the creative process, far removed from the typical, stereotyped trends in the sphere of modern industrialization. He goes one step further in his work by attempting to restore aesthetic dignity to the objects of daily life, in a search for beauty within the immediate environment.hin the immediate environment.