• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.140-146
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• 2018

Recently, VLC(Visible Light Communication) fusing with LED(Light Emitting Diode) used in indoor lighting and wireless communication technology has attracted attention. However, the VLC can communicate only within the coverage to measure the optical signal and the communication disconnection phenomenon is occur in the NLoS(Non-Line-of-Sight) area. In this paper, we propose VLC relay module to extend the coverage of VLC and improve the communication disconnection phenomenon in NLoS area. The proposed VLC relay module transmits the packet received from the transmitter to the VLC relay module and receiver. The experiment was carried out by installing one VLC transmitter and three VLC relay modules, communication coverage expansion and the improvement of communication disconnection phenomenon in the NLoS were confirmed by the increase of the VLC relay module. Also, we confirmed that the optical signal measurement performance is improved 2.4 times by using the dual sampling method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.163-168
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• 2011

In this paper, we propose an emotion transfer system based on LED, which presents and transmitts users emotion through Bluetooth and ZigBee using LED light. We propose an emotional LED system interacting multiple LED lighting system and implement the proposed system using smartphone and WPAN network with Bluetooth and ZigBee. For the transmission of data, ZigBee is adopted for each LED lighting system and Bluetooth is utilized for the smartphone. Also, the LED lighting systems which are connected to smartphone have both ZigBee and Bluetooth module for the heterogeneous network. The implemented system shows the validity and applicability of the proposed system.

• Fashion & Textile Research Journal
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• v.22 no.1
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• pp.55-65
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• 2020

Smart photonic clothing integrates light emitting technology inside and outside of the garment and integrates it as a fashion product. It expresses digital color that radiates light outside the body that expands the functionality of the clothing as well as makes new and various attempts visually. It is also is gradually expanding into a new area of fashion. LED, one of the digital color output devices, is a light emitting device that is suitable for presenting consumer customized designs in that the patterns and colors of clothes can be modified as desired by utilizing computer technology such as program coding. LED technology that can realize various digital colors is actively applied in various industrial design fields, but there are few previous studies on smart clothes using LED color in Korean fashion fields. Therefore, this study develops a prototype of a customized LED smart photonic garment that allows the user to directly participate in the color implementation of clothing and select a digital color suitable for the desired function. The LED module was designed to be detachable from clothing and made using a 256-pixel LED matrix. Various coding patterns of the LED were designed using the coding change of Arduino program.

• Journal of the Korean Society of Radiology
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• v.6 no.3
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• pp.207-215
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• 2012

As one of photo dynamic therapies, the existing LED photo irradiation method with 635 nm continuous wave has most frequently been used for acne treatment, it suffered from a low energy efficiency and generation of a large amount of heat in tissues requiring improvement measures. In this thesis, a LED photo irradiation system for acne treatment has been designed using PWM(Pulse Width Modulation) mode to enhance the energy efficiency and prevent thermal destruction in tissues. System configuration consisting largely of timer module, PWM module, and photo transfer device has been designed with the use of 1 W LED at a wavelength of 660 nm for the photo transfer device to increase skin penetration depth for treatment of acne. Frequency and wave form generated by using PWM control was verified along with confirmation of output energy of 660 nm LED and surface temperatures of tissues, followed by evaluation of stable energy outputs and stability of tissues. The results indicated that whereas power loss was high and thermal destruction in tissues was exhibited when C.W mode was used to obtain the optical energy of 1 W LED at a wavelength of 660 nm for acne treatment, realization of PWM mode allowed lowering of power consumption for LED through pulse width modulation, and no occurrence of thermal destruction in tissues, suggesting that PWM mode is safer and more effective for treatment of acne than C.W mode.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.95-100
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• 2010

LED (Light Emitting Diode) is 85% of the applied energy is converted into heat that is already well known. Lately, LED chips increasing the capacity as result delivered to increase the heat of the LED products and module that directly related to life span and degradation. Thus, in industry the high-power LED chip to control the heat generated during the course of the study and the existing aluminum, copper adhesives, and uses MLC (Metal clad laminate) structures using low-cost FR4 and copper CCL (Copper Clad Laminate) to reduce costs by changing to a study being carried out. In this study, using low-cost CCL Class, mounted 1W LED chip to analyze changes in the thermal resistance. In addition, heat dissipation in the CCL to facilitate a variety of thermal via design outside of the heat generated by the LED chip to control and facilitate the optimal structure of the heat dissipation is suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.252-255
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• 2010

In this thesis, it suggests large scale interactive display system which is able to various touch interaction and bases on infrared LED BAR and using 3D. Interaction layer formed on space from screen which is able to feel 3D using suggested IR LED BAR. It gets the image in real time what is composed in interaction section using infrared camera with band pass filter. The image finds touch interaction coordinate through image processing module and saves as packet. It send packet to server through network data communication. It analyze packet by metaphor analysis module and save as metaphor event and send it to contents. On contents, it practices to metaphor event result in real time so it makes use touch interaction in stereopsis. According to this process, it does not need touch the screen at firsthand but it is possible system and touch interaction so touch interaction is possible while use 3D.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.1
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• pp.103-113
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• 2019

The purpose of this study was to develop an e-textile using LEDs that can enhance visual and functional effects, and to identify their applicability to sportswear. By applying the design elements of fashion design concretely with LEDs, an e-textile design module is developed and that module is applied to the product, so LED application design can be proposed for use in a practical product. E-textiles have been divided into five categories, and their usefulness were verified by applying e-textiles to men's and women's sportswear. The product beign considered has a built-in tilt sensor, which illuminates the LEDs according to the user's movements, and allows the LEDs to be turned on or off in accordance to the user's preference. E-tatoo is a type of LED application that enhances the appearance by placing LEDs on a small area, emphasizing origin points, just like an actual tattoo. Designed with LEDs arranged in a straight line and various curved forms, e-strips can provide a function that matches the characteristics of each section of clothing or fashion item. E-wappen uses about 7-10 LEDs to give motifs a strong sense of visibility, thus adding to their vibrancy. E-panels and e-clothes were able to produce creative and high-value textures. It is also expected to be used for special purposes or bags as it is possible to produce high value-added textures that are creative and aesthetically beautiful. For instance, a progressive LED string on the straight line of female leggings can further emphasize rhythmic movements during exercise, and e-wappen also serves the purpose of nighttime protection. It is also believed that the application of dance or dance-related sportswear will make the movement of the performance more intense and lively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.284-288
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• 2015

The color temperature flexibility-typed Lighting Emitting Diode(LED) lighting control system proposed in this thesis employs Pulse Width Modulation(PWM) technique to control the brightness of LED lighting. The LED lighting used as a light source has 20W downlight composed of two types of LED chips: one is Warm White and the other is Cool white. One multi-sensor module consisting an infrared sensor, an illumination sensor, and a temperature sensor was made, to which Bluetooth wireless communication technique was applied to enable a smartphone application to control lighting brightness and identify the information collected from the sensor. CS-1000, a spectroradiometer, was used to measure LED dimming control and the changing values of a color temperature in eight steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5600K of Cool White LED.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.55-58
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• 2004

Recently the examples of a lighting design with LED source have increased rapidly, but there are few researches that are related to selecting luminous colors by LED. The research is that respondents operated color blender and got preference colors according to what they made, the colors were measured by chroma meter and marking CIE 1931 chromaticity diagram. Through the results of the research has made group preference for luminous colors. From now on, not only does it seem capable of using a designing a building-lighting to which LED but it will be actively applied to controlling with a digital technology for lighting design.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.123-133
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• 2017

In this paper, we developed an optimal flicker-free control algorithm operating within 16 luminance implementation bits and 512 brightness implementation pulses irrespective of LPM(LED Pixel Matrix) module configuration on dynamic driving method of LED display system. As an implementation method, we turned the refresh rate up by increasing the number of scans through multiple shift-latches which were devised from conventional shift-latch scheme for full color representation. As a result, the LED display system of this method has no flicker phenomenon because of the novel refresh rate higher than 2,040[Hz] incomparable to 240~480[Hz] of conventional system.