• ETRI Journal
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• v.31 no.6
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• pp.784-794
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• 2009

We present a full HD (1080p) H.264/AVC High Profile hardware encoder based on fast motion estimation (ME). Most processing cycles are occupied with ME and use external memory access to fetch samples, which degrades the performance of the encoder. A novel approach to fast ME which uses shared multibank memory can solve these problems. The proposed pixel subsampling ME algorithm is suitable for fast motion vector searches for high-quality resolution images. The proposed algorithm achieves an 87.5% reduction of computational complexity compared with the full search algorithm in the JM reference software, while sustaining the video quality without any conspicuous PSNR loss. The usage amount of shared multibank memory between the coarse ME and fine ME blocks is 93.6%, which saves external memory access cycles and speeds up ME. It is feasible to perform the algorithm at a 270 MHz clock speed for 30 frame/s real-time full HD encoding. Its total gate count is 872k, and internal SRAM size is 41.8 kB.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.12-16
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• 2007

In this paper, The 3rd-IMD of class-F power amplifier is improved using CMRC structure in order to remove the parasitic End harmonic at the output load of class-F power amplifier. The total size is very small more than class-F power amplifier using PBG. (Photonicband Gap) structure during improved 3rd-IMD characteristic performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2622-2627
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• 2010

The accuracy of face recognition used unmanned security system is very important and necessary. However, face recognition is a lot of restriction due to the change of distortion of face image, illumination, face size, face expression, round image. We propose a hybrid neural network for improve the performance of the face recognition. The proposed method is consisted of SOM and LVQ. In order to verify usefulness of the proposed method, we make a comparison between eigenface method, hidden Markov model method, multi-layer neural network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.487-492
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• 2016

In this paper, a device for analyzing the pressure distribution during walking was produced by using the pressure sensor on the heel. This device was limited to a frequency band by using the 1st low-pass filter. And an algorithm to analyze the value of the quantity to pressure using a analog to digital converter. It is used by using the threshold voltage of pressure sensor, it is suggested the algorithm. The algorithm is detected the peak which is exceeded the threshold voltage. and thus in accordance, it is detected the number of steps. And the calorie consumption were detected by using it. Also it used an MCU and Bluetooth. And by confirming the data at the LCD of the other MCU, it was to reduce the size of the device. According to this algorithm, it has the advantage that there is no restriction on the activity than when using an imaging device and it is inexpensive than other sensors such as an acceleration sensor or a gyro and it is easy to handle.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.355-358
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• 2010

As CMOS technology continues to scale down, signal processing is favorably done in the digital domain, which requires Analog-to-Digital (A/D) Converter to be integrated on-chip. This paper presents a design methodology of 12-bit 1-MS/s Rail-to-Rail fully differential SAR ADC using Deep N-well Switch based on binary search algorithm. Proposed A/D Converter has the following architecture and techniques. Firstly, chip size and power consumption is reduced due to split capacitor array architecture and charge recycling method. Secondly, fully differential architecture is used to reduce noise between the digital part and converters. Finally, to reduce the mismatch effect and noise error, the circuit is designed to be available for Rail-to-Rail input range using simple Deep N-well switch. The A/D Converter fabricated in a TSMC 0.18um 1P6M CMOS technology and has a Signal-to-Noise-and-Distortion-Ratio(SNDR) of 69 dB and Free-Dynamic-Range (SFDR) of 73 dB. The occupied active area is $0.6mm^2$.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.149-159
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• 2011

In this paper, we study the problem of how to design a medical-grade wireless local area network (WLAN) for healthcare facilities. First, unlike the IEEE 802.11e MAC, which categorizes traffic primarily by their delay constraints, we prioritize medical applications according to their medical urgency. Second, we propose a mechanism that can guarantee absolute priority to each traffic category, which is critical for medical-grade quality of service (QoS), while the conventional 802.11e MAC only provides relative priority to each traffic category. Based on absolute priority, we focus on the performance of real-time patient monitoring applications, and derive the optimal contention window size that can significantly improve the throughput performance. Finally, for proper performance evaluation from a medical viewpoint, we introduce the weighted diagnostic distortion (WDD) as a medical QoS metric to effectively measure the medical diagnosability by extracting the main diagnostic features of medical signal. Our simulation result shows that the proposed mechanism, together with medical categorization using absolute priority, can significantly improve the medical-grade QoS performance over the conventional IEEE 802.11e MAC.

• ETRI Journal
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• v.38 no.5
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• pp.847-857
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• 2016

Broadcasting services such as multi/single channel HDTV and 3DTV/2DTV use a multi-channel encoder that changes the bitrate and composition of the video service depending on the time. However, this type of multi-channel encoder could cause a longer latency owing to the variable bitrate and relatively bigger size of the buffers, which results in the same delay as in 3DTV even for a conventional DTV service. On the other hand, systems built based on separate encoders, each of which is optimized for the target service, might not have such latency problems. Nevertheless, there might be a distortion problem in the image and sound at the time of a switchover between two encoders with different output bitrates and group of picture structures. This paper proposes a system that can realize a seamless video service conversion using two different video encoders optimized for each video service. An overall functional description of the video service change control server, which is a main control block for the proposed system, is also provided. The experiment results confirm the seamless switchover and reduced broadcasting latency of DTV services compared with a broadcasting system composed of a multi-channel encoder system.

• Fashion & Textile Research Journal
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• v.13 no.3
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• pp.398-408
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• 2011

This study shows that the self-satisfaction individually is rising and social life is attracted effective and successful in image making field by structuring the facial image improvement program through experimental study in order to improve unbalance of women's face. Experiment is conducted by electing 3 samples for 12 weeks and analyzing the measurement and visual analysis, infrared thermography, and evaluation of experts in order to check the facial unbalance. Subject 1 had the effect at approximately in 4 weeks with the severely distorted chin line and mouth appendage. The facial outline became softer to turn entire image to be softer and more feminine. Subject 2 had the severe distortion of location and size of eyes and nose. But the skin was getting better at first, followed by eyes getting clearer with the location changed in left and right. Subject 3 had the twisted nose and lower chin, but after two weeks, the eye area and skin were better and the width of left and right chin was similarly changed. On the basis of the above research result, the program to effectively improve the image was structured and presented with the resolution of facial unbalance. Program is consist of the training of breathing method, face washing method, facial muscle exercise.

• Journal of Magnetics
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• v.12 no.3
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• pp.103-107
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• 2007

Magnetic field induced structural transition has been systematically investigated for $La_{1-x}Ba_xMnO_3$ with the fine control of carrier doping $(0.15{\leq}x{\leq}0.20)$. Application of a magnetic field results in the suppression of the rhombohedral-orthorhombic transition temperature $(T_s)$ and the increase of insulator-metal transition temperature $(T_{MI})$. Near x = 0.17, where $T_S$ is similar to $T_{MI}$ at zero magnetic field, we found that the $T_S$ smoothly decreased with magnetic field even though it intersected the $T_{MI}$ near 3 T. Also, the magnetostructural phase diagram obtained from the temperature sweep and from the magnetic field sweep is not significantly modified. By comparing the magnetostructural transition in $La_{1-x}Sr_xMnO_3$, we have suggested that the large disorder originated from ionic size differences between La and Ba may weaken the sensitivity of the kinetic energy of $e_g$ electrons on the degree of lattice distortion in $La_{1-x}Ba_xMnO_3$.

• Wind and Structures
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• v.9 no.1
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• pp.23-35
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• 2006

The effect of buildings on flow in urban canopy is one of the most important problems in local/micro-scale meteorology. A large eddy simulation model is used to simulate the flow structure in an urban neighborhood and the bulk effect of the buildings on surrounding flows is analyzed. The results demonstrate that: (a) The inflow conditions affect the detailed flow characteristics much in the building group, including: the distortion or disappearance of the wake vortexes, the change of funneling effect area and the change of location, size of the static-wind area. (b) The bulk effect of the buildings leads to a loss of wind speed in the low layer where height is less than four times of the average building height, and this loss effect changes little when the inflow direction changes. (c) In the bulk effect to environmental fields, the change of inflow direction affects the vertical distribution of turbulence greatly. The peak value of the turbulence energy appears at the height of the average building height. The attribution of fluctuations of different components to turbulence changes greatly at different height levels, in the low levels the horizontal speed fluctuation attribute mostly, while the vertical speed fluctuation does in high levels.