• Transactions on Electrical and Electronic Materials
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• v.8 no.6
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• pp.268-273
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• 2007

In this study, It was studied about the luminance characteristics of 17 inch direct-type back light using EEFL(external electrode fluorescent lamp) and CCFL(cold cathode fluorescent lamp). The EEFL has a long life time because the electrode is installed outside of lamp. And it is produced in lower price than conventional CCFL. Moreover, it does not need process of installing internal electrode. However, the EEFL technology has several problems such as difficulty of designing driving inverter and preventing this phenomenon along the skin of lamps. We suggested two types of backlight unit for LCD TV application using the EEFL and the CCFL. We found optimized optical design parameters. We set the optical variation parameters such as lamp height, lamp distance, total thickness, and angles of inner walls. We achieved 7580 nits of center luminance, 82% of luminance uniformity by using 20 lamps of the EEFL and 7297 nits of center luminance, 78% of luminance uniformity by using 16 lamps of the CCFL.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.6
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• pp.366-371
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• 2017

In this paper, we introduce an electrocardiogram (ECG) system designed to solve problems caused by wetgels and motion artifacts in measuring active movement. The system is called a dry-contact ECG and was designed by considering impedance matching between skin and electrode as well as the frictional electricity between electrode and clothes. In order to create the system, we measured impedance on the skin-electrode interface, and the result was applied to the electronic circuit scheme. Moreover, we added an electrode on the back of the measurement electrode to make a flow path to ground the electrical noise. The final ECG circuit and novel electrode were used to detect real human cardiac signals from a subject who was tested while standing still and walking. The signals obtained from the two activities were nicely shaped, without any motion artifact noise. We took electrode size into account in this study because the impedance depended on the area of the electrode. An electrode of 50 mm diameter showed the best curve for the ECG signal without any electrical noise.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.179-184
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• 2015

An app is designed and developed for safe use of cosmetics by notifying the expiration date of cosmetics. According to increasing uses of cosmetics for modern people, the expiration date of cosmetics is becoming more important. The app proposed in this paper will be used for self management. People may manage themselves by registering the expiration date of their cosmetics. The cosmetics are registered and managed by category. This app also provides some beauty tips depending on the skin types of people.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.79-85
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• 2017

Understanding of human emotion has a high importance in interaction between human and machine communications systems. The most expressive and valuable way to extract and recognize the human's emotion is by facial expression analysis. This paper presents and implements an automatic extraction and recognition scheme of facial expression and emotion through still image. This method has three main steps to recognize the facial emotion: (1) Detection of facial areas with skin-color method and feature maps, (2) Creation of the Bezier curve on eyemap and mouthmap, and (3) Classification and distinguish the emotion of characteristic with Hausdorff distance. To estimate the performance of the implemented system, we evaluate a success-ratio with emotional face image database, which is commonly used in the field of facial analysis. The experimental result shows average 76.1% of success to classify and distinguish the facial expression and emotion.

• Electronics and Telecommunications Trends
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• v.34 no.5
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• pp.48-57
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• 2019

As the super-aged society approaches rapidly, the number of people suffering from post-stroke and other neurological disorders is significantly increasing, where prompt and intensive rehabilitation is essential for such people to resume their physical activities in normal daily lives. To overcome the inherent limitations of manual physical therapy, various types of exoskeleton robots are being employed. However, the need of the hour is softer, thinner, lighter, and even stretchable systems for precisely monitoring the motion of each joint without restricting the patients' movements in rehabilitation tasks. In this paper, we discuss the technological trends and current status of emerging stretchable rehabilitation systems, in which sensors, interconnects, and signal-processing circuits are monolithically integrated within a single stretchable substrate attachable to the skin. Such skin-like stretchable rehabilitation devices are expected to provide much more convenient, user-friendly, and motivating rehabilitation to patients with neurological impairments.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.1
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• pp.82-89
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• 2016

And by entering into an aging society with economic growth "beautiful and healthy desire to live', aesthetics industry as promote interest in 'Anti-aging' is emerging as a promising business increased significantly the skin care market. However, the management of the hospital or the temporal order to receive professional care providers, spatial, and cost constraints caused many companies to solve this problem began to approach the Home Care Area. Global trends in personal skin care market has been activated, the domestic has been activated at low cost, private market due to the recession. We have performed this test in order to develop a skin care device for home in order to compensate for this point.In this paper, we develop a low-level laser to create a personal skin care products and sought to incorporate them into the skin cosmetic.Expand the pores by using the low-level laser to the skin by to the dermal layer of the skin was penetrated aim experiment the ampoule, and by a comparison of the medical low-level laser reliability and determine the effectiveness or absence of the performance and efforts to commercialize.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.1
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• pp.14-19
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• 2021

This study has attempted to use ozone for the treatment of skin diseases as research results that ozonated olive oil has an excellent therapeutic effect on skin diseases are known. However, there is hardly any accurate data in Korea. Usually, animal tests related to cosmetics are not performed, but toxicity tests were conducted because they were absolutely necessary. In general, there are not many cases of measuring actual data through animal tests for the purpose of confirming the performance of cosmetics, but in the case of toxicity tests, it is recommended to accurately measure skin reactions, so this experiment was conducted. In this experiment, in order to evaluate the skin irritation of ozonated oil (high concentration) on the rabbit, the test substance was applied to the back of the rabbit for 24 hours, and then mortality, general symptoms and skin irritation were evaluated. Experimental Results As a result of evaluating the treatment site of the test substance after a certain period of time, no skin irritation was observed in all animals.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.525-530
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• 2023

Stretchable piezoelectric energy harvester (S-PEHs) based on composite materials are considered one of the potential candidates for realizing wearable self-powered devices for smart clothing and electronic skin. However, low energy conversion performance and expensive stretchable electrodes are major bottlenecks hindering the development and application of S-PEHs. Here, we fabricated the S-PEH by adopting the piezoelectric composites with enhanced stress transfer properties and kirigami-patterned textile electrodes. The optimum contents of piezoelectric BaTiO₃ nanoparticles inside the carbon nanotube/ecoflex composite were selected as 30 wt% considering the trade-off between stretchability and energy harvesting performance of the device. The final S-PEH shows an output voltage and mechanical stability of ~5 V and ~3,000 cycles under repeated 150% of tensile strain, respectively. This work presents a cost-effective and scalable way to fabricate stretchable piezoelectric devices for self-powered wearable electronic systems.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.2
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• pp.163-172
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• 2005

When tracking a human face in the moving pictures with complex background under irregular lighting conditions, the detected face can be larger including background or smaller including only a part of the face. Even background can be detected as a face area. To solve these problems, this paper proposes a new face tracking method using a block difference image and a Kalman estimator. The block difference image allows us to detect even a small motion of a human and the face area is selected using the skin color inside the detected motion area. If the pixels with skin color inside the detected motion area, the boundary of the area is represented by a code sequence using the 8-neighbor window and the head area is detected analysing this code. The pixels in the head area is segmented by colors and the region most similar with the skin color is considered as a face area. The detected face area is represented by a rectangle including the area and its four vertices are used as the states of the Kalman estimator to trace the motion of the face area. It is proved by the experiments that the proposed method increases the accuracy of face detection and reduces the fare detection time significantly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.81-87
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• 2021

In this study the skin care system was designed and tested by introducing V-IPL(Variable-Intense Pulse Light) methods that allow various skin treatments. The discharge method, a new method of switching on the flash lamp sequentially according to the lesions, was used. Pulse shape control is implemented in the system using the conventional LC variable method and the switching method control method of the switching element. As a result, the pulse width could be varied up to 1[㎛] by using a microprocessor, and by turning on the flash lamp sequentially along the lesions the depth and width, the pulse shape and pulse shape could be more diverse. We could also make long pulses of up to 1~100[ms] in various pulse width. And the special differences between the existing system and the proposed system in this study are as follow. Existing system is one pulse(pulse width : 1~40ms) and proposed system is three pulse(pulse width : 1~100ms).