• The KIPS Transactions:PartC
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• 제17C권3호
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• pp.251-258
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• 2010

In an indoor localization method taking the lateration-based approach, the location of a target is estimated with the location of anchor points (APs) and the approximated distances between the target and APs using received signal strength (RSS) measurements. The accuracy of distance estimation affects the localization accuracy of a lateration-based method. Since a radio propagation environment varies randomly in time and space, the highest RSSs do not necessarily give the best estimation of the distances between a target and APs. Thus, all APs hearing a target have been used for localization. However, the accuracy of a lateration-based method degrades if more APs beyond a certain threshold are used because the area of polygon with the APs increases. In this paper, we focus on reducing the size of the polygon to further increase the localization accuracy. We use the centroid of the polygon as a reference point to estimate the relative location of a target in the polygon. Once the relative location is estimated, only the APs which are closest to the target are used for localization to reduce the area of the polygon with the APs. We validate the proposed method by implementing an indoor localization system and evaluating the accuracy of the proposed method in the various experimental environments.

• Nuclear Engineering and Technology
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• 제21권4호
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• pp.287-293
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• 1989

The purpose of this study was to develop a rapid and effective method of laser-induced fluorescence analysis for thrace amounts of Sm, Eu and Tb in nuclear fuels. The features of the method are the use of the distinct fluorescence wavelengths and the discriminative lifetimes of the respective elements when excited by a pulsed nitrogen laser. Fluorescence signals of the three elements were isolated by adequate selection of the filters or complexing agents (HFA, TTA) or discriminative delay and gate times in the signal processing circuit. It was found that S $m^{+3}$ and E $u^{+3}$ emitted strong fluorescence in the two complexing agent solutions or HFA and TTA. But in the case or T $b^{+3}$, the fluorescence signal was detected only in HFA solution. With respect to the concentrations of S $m^{+3}$, E $u^{+3}$ and T $b^{+3}$, the fluorescence signal intensities gave superior linearities in the range of 5 ppb-10 ppm for S $m^{+3}$, 0.5 ppb-1 ppm for E $u^{+3}$, and 0.1 ppb-300 ppb for T $b^{+3}$, The detection limits obtained were 5 ppb for S $m^{+3}$, 0.1 ppb for E $u^{+3}$, and 0.01 ppb for T $b^{+3}$, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제20권7호
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• pp.1383-1388
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• 2016

Although image signal processing is used in many fields, degradation takes place in the process of transmitting image data by several causes. CWMF, A-TMF, and AWMF are the typical methods to eliminate noises from image data damaged under salt and pepper noise environment. However, those filters are not effective for noise rejection under highly dense noise environment. In this respect, the present study proposed an algorithm to remove in salt and pepper noise. In case the center pixel is determined to be non-noise, it is replaced with original pixel. In case the center pixel is noise, it segments local mask into 4 directions and uses linear interpolation to estimate original pixel. And then it applies spatial weight to the estimated pixel. The proposed algorithm shows a high PSNR of 24.56[dB] for House images that had been damaged of salt and pepper noise(P = 50%), compared to the existing CWMF, A-TMF and AWMF there were improvements by 16.46[dB], 12.28[dB], and 12.32[dB], respectively.

• Journal of the Institute of Electronics and Information Engineers
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• 제50권6호
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• pp.131-137
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• 2013

The barrel distortion makes serious problems in a wide-angle camera employing a lens of a short focal length. This paper presents a low-complexity hardware architecture for a real-time barrel distortion corrector and its implementation. In the proposed barrel distortion corrector, the conventional algorithm is modified so that the correction is performed incrementally, which results in the reduction of the number of required hardware modules for the distortion correction. The proposed barrel distortion corrector has a pipelined architecture so as to achieve a high-throughput correction. The correction rate is 74.86 frames per sec at the operating frequency of 314MHz in a $0.11{\mu}m$ CMOS process, where the frame size is $2048{\times}2048$. The proposed barrel distortion corrector is implemented with 14.3K logic gates.

• The KIPS Transactions:PartC
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• 제13C권6호
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• pp.677-684
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• 2006

This paper investigates the link margin of MB-OFDM UWB system quantitatively. Various simulations are performed considering the implementation loss by imperfect synchronization unit and the effect of multi-path fading channels. MB-OFDM UWB system uses ZP(Zero Padding) instead of CP(Cyclic Prefix) and supports two transmission modes; one is TFI(Time Frequency Interleaving) mode that transmits OFDM symbols using different carrier frequency from symbol to symbol according to Time Frequency(TF) codes, the other is FFI(Fixed Frequency Interleaving) mode that transmits OFDM symbols using a specific carrier frequency. The advantage of if and TFI is to be able to increase the transmitting power effectively compared to the existed OFDM systems that transmit the signal continuously at the same average transmitting power. From the analysis results of Ink margin, to guarantee the service range of 4m in 200Mbps mode, TFI mode must necessarily be implemented and the service range of 480Mbps mode is estimated about 1-2m in the line-of-sight multi-path channel (CMI).

• Journal of IKEEE
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• 제14권1호
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• pp.8-16
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• 2010

This paper presents a design of the successive approximation ADC(SA-ADC) applicable to a midium-low speed analog-front end(AFE) for the maximum 15MS/s CCD image processing. SA-ADC is effective in applications ranging widely between low and mid data rates due to the large power scaling effect on the operating frequency variations in some other way of pipelined ADCs. The proposed design exhibits some distinctive features. The "differential capacitor-coupling scheme" segregates the input sampling behavior from the sub-DAC incorporating the differential input and the sub-DAC output, which prominently reduces the loading throughout the signal path. Determining the MSB(sign bit) from the held input data in advance of the data conversion period, a kind of the signed successive approximation, leads to the reduction of the sub-DAC hardware overhead by 1 bit and the conversion period by 1 cycle. Characterizing the proposed design in a 3.3 V $0.35-{\mu}m$ CMOS process by Spectre simulations verified its validity of the application to CCD analog front-ends.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제27권1C호
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• pp.69-77
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• 2002

Sine digital signal processing for motion pictures requires huge amount of data computation to store, manipulate and transmit, more effective data compression is necessary. Therefore, the ITU-T recommended H.26x as data compression standards for digital motion pictures. The data compression method that eliminates time redundancies by motion estimation using relationship between picture frames has been widely used. Most video conding systems employ block matching algorithm for the motion estimation and compensation, and the algorithm is based on the minimun value of cast functions. Therefore, fast search algorithm rather than full search algorithm is more effective in real time low data rates encodings such as H.26x. In this paper, motion estimation employing the Nearest-Neighbors algorithm is designed to reduce search time using FPGA, coded in VHDL, and simulated and verified using Xilink Foundation.

• The KIPS Transactions:PartB
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• 제14B권2호
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• pp.71-80
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• 2007

In this paper, We propose face type classification, tongue region extraction and tongue color analysis method for Oriental medicine diagnosis system to supply web based medical treatment information. This presents to construct system that takes super aging society and uses ocular inspection and longue diagnosis in web-based to embody this by an IT Technology as generalization and popularization of medical benefit are social requirement and supplies medical treatment information. Place that reflect living body signal of human body ordinarily and appear becomes iris or tongue, five sensory organs etc. This paper proposes classification of face type, extraction of five sensory organs for observing a person's shape and color among diseases diagnosis based on home health care that propose to develop and region extraction and color analysis etc, of tongue which intensively represents the bio-signals of human-beings. Finally, the effectiveness of this paper is verified by several experiments.

• Journal of KIISE:Software and Applications
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• 제28권10호
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• pp.699-705
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• 2001

As it became possible to generate 3D sound on a PC environment due to the advances in computing performance and digital signal processing technology, 3D sound technology gains its focus in the multimedia area Specifically a two-channel based 3D sound technology is being studied by many researchers because of its space efficiency and economical structure. While the positional sound effect is simple in its implementation, the moving sound effect has many problems to be resolved as there are only discrete measured point of HRTF database. In this paper, we propose the method of generating smooth moving sound in a two-channel based 3D sound technique with respect to generating smooth trajectory, and the interpolation method of discrete measured HRTF data. We perform the tests in the PC environment and prove the utility of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제37권2C호
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• pp.181-187
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• 2012

Millimeter wave (MMW) readily penetrates fabrics, thus it can be used to detect objects concealed under clothing. A passive MMW imaging system can operate as a stand-off type sensor that scans people in both indoors and outdoors. However, because of the diffraction limit and low signal level, the imaging system often suffers from low image quality. Therefore, suitable statistical analysis and computational processing would be required for automatic analysis of the images. In this paper, a real-time concealed object detection is addressed by means of the multi-level segmentation. The histogram of the image is modeled with a Gaussian mixture distribution, and hidden object areas are segmented by a multi-level scheme involving $k$-means, the expectation-maximization algorithm, and a decision rule. The complete algorithm has been implemented in C++ environments on a standard computer for a real-time process. Experimental and simulation results confirm that the implemented system can achieve the real-time detection of concealed objects.