• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.109-116
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• 2019

This study proposed a robust detection algorithm. It detects face more stably with respect to changes in light and rotation for the identification of a face shape. Also it satisfies both efficiency of calculation and the function of detection. The algorithm proposed segmented the face area through pre-processing using a face shape as input information in an environment with a single camera and then identified the shape using a Self Organized Feature Map(SOFM). However, as it is not easy to exactly recognize a face area which is sensitive to light, it has a large degree of freedom, and there is a large error bound, to enhance the identification rate, rotation information on the face shape was made into a database and then a principal component analysis was conducted. Also, as there were fewer calculations due to the fewer dimensions, the time for real-time identification could be decreased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.1
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• pp.79-87
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• 1989

The influence of anchor slope on behavior of sheet pile is analysed by results of model test. It can be seen that the larger inclination of anchor causes more causes more increases of the horizontal and vertical deflection of wall, but the bending moment is less influenced by the inclination of anchor. The negative friction against vertical settlement of wall has the yielding point at the excavation level of 0.71-0.80 H. The redistribution of earth pressure on the sheet pile with dredging must be considered by soil-arching. The zero pressure point from the toe of wall is 20% higher than that of the Free Earth Support Method. It is also observed that the angle of failure planes to major principal plane is larger than the angle of $45^{\circ}+{\phi}/2$.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.6
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• pp.1-8
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• 1999

Multi-carrier CDMA is a transmission scheme where data symbols are spread in the frequency domain with a spread code then transmitted using multiple carriers. It is robust against narrowband interference because of its long symbol duration. However, due to large sidebands of the rectangular window frequency response, subchannels spectrally overlap with neighboring subchannels, which leads to substantial intercarrier interference in a dispersive channel. In this paper, we consider a mult-carrier CDMA system where subchannel spectral containment is achiveved by M-band cosine modulated filter bank (CMFB). In CMFB based MC-CDMA, subchannel spectral containment is achieved using the filter bank of longer impulse response than that of conventional discrete Fourier transform (DFT) filter bank. We show that spectral containment feature of the CMFB based fading channel is analyzed using computer simulations.

• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1227-1238
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• 2005

Recently, with the advance of network and internet technologies, it is appeared the Problem that the digital contents such as image, voice and video are illegally pirated and distributed. To protect the copyright of the digital contents, the digital watermarking technology of inserting the provider's information into the contents has been widely used. In this paper, we propose the method of applying the digital watermarking into biometric information such as fingerprint and iris in order to prevent the problem caused by steal and misuse. For that, we propose the method of inserting watermark in frequency domain, compare the recognition performance before and aster watermark inserting. Also, we experiment the robustness of proposed method against blurring attack, which is conventionally taken on biometrics data. Experimental results show that our proposed method can be used for protecting iris and fingerprint data, efficiently.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.53-61
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• 2006

This paper is proposed adaptive fuzzy-neuro controller for high performance of induction motor drive. The design of this algorithm based on fuzzy-neural network controller that is implemented using fuzzy control and neural network. This controller uses fuzzy nile as training patterns of a neural network. Also, this controller uses the back-propagation method to adjust the weights between the neurons of neural network in order to minimize the error between the command output and actual output. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the adaptive fuzzy-neuro controller is evaluated by analysis for various operating conditions. The results of experiment prove that the proposed control system has strong high performance and robustness to parameter variation, and steady-state accuracy and transient response.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.40-49
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• 2008

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications and so of due to their excellent power to weight ratio. To obtain maximum efficiency in these applications, this paper proposes the neural network control method. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the error back propagation algorithm(EBPA) of neural network. The minimization of loss is possible to realize eHciency optimization control for the IPMSM drive. This paper proposes high performance and robust control through a real time calculation of parameter variation such as variation of back emf constant, armature resistance and d-axis inductance about the motor operation. Proposed algorithm is applied IPMSM drive system, prove validity through analysis operating characteristics con011ed by efficiency optimization control.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.347-356
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• 2017

It is well-known that the face recognition method via sparse representation has been proved very robust and showed good performance. Its weakness is, however, that its time complexity is very high because it should solve $L_1$-minimization problem to find the sparse solution. In this paper, we propose to use the ROMP(Regularized Orthogonal Matching Pursuit) method for the sparse solution, which solves the $L_2$-minimization problem with regularization condition using the greed strategy. In experiments, we shows that the proposed method is comparable to the existing best $L_1$-minimization solver, Homotopy, but is 60 times faster than Homotopy. Also, we proposed C-SCI method for classification. The C-SCI method is very effective since it considers the sparse solution only without reconstructing the test data. It is shown that the C-SCI method is comparable to, but is 5 times faster than the existing best classification method.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.189-193
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• 1997

Aspheric pick-up lenses are increasingly used in consumer products such as computer and multimedia, as their mass production has become possible owing to the injection molding process. However still much work needs to be done for more effective manufacture of aspheric lenses, one area of which is the in-line inspection of produced lenses. In this paper, we present a lateral-shearing interferometer that has specially been designed to have a high immunity to external vibration and atmospheric disturbance. The interferometer comprises four prisms. They are directly attached to each other using an immersion oil so that relative sliding motions between the prisms are allowed. Their relative displacement can readily generate necessary lateral-shearing and phase-shifting to determine the wavefront of the beam collimated by the lens under inspection. A special phase-measuring algorithm of arbitrary-bucket is adopted to compensate the phase-shifting error caused by the thickness reduction in the immersion oil. Zernike polynomial fitting has done for determinating quantitative aberration of aspheric pick-up lenses. The interferometer built in this work is robust to external mechanical vibration and atmospheric disturbance so that experimental results show that it has a repeatability of less than λ/100.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10A
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• pp.816-829
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• 2003

In this paper, we evaluate the performance of PN (Pseudo Noise) code based time hopping sequences for M-ary UWB (Ultra Wide Band) multiple access systems using the equicorrelated signal sets. In particular, we consider two different types of M-ary UWB systems in UWB indoor wireless multipath channels: The first type of the systems (System #1) has identical symbol transmission rate regardless of the number of symbols M since the length of signal pulse train is fixed while M increases, and the second type of the systems (System #2) has the same bit transmission rate regardless of M since the length of signal pulse train is extended according to the increase of M. We compare the proposed systems with those using the ideal random time hopping sequence in terms of the symbol error rate performance. Simulation results show that the PN code based time hopping sequence achieves quite good performance which is favorably comparable to that of the ideal random sequence. Moreover, as M increases, we observe that System #2 shows better robustness against multiple access interference than System # 1.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.9
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• pp.889-897
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• 2010

Recently, a cutting-edge large-scale image database system has demanded these attributes: search with alarming speed, performs with high accuracy, archives efficiently and much more. An image identifier (descriptor) is for measuring the similarity of two images which plays an important role in this system. The extraction method of an image identifier can be roughly classified into two methods: a local and global method. In this paper, the proposed image identifier, LFH(Local Feature's Histogram), is obtained by a histogram of robust and distinctive local descriptors (features) constrained by a district sub-division of a local region. Furthermore, LFH has not only the properties of a local and global descriptor, but also can perform calculations at a magnificent clip to determine distance with pinpoint accuracy. Additionally, we suggested a way to extract LFH via GPU (OpenGL and GLSL). In this experiment, we have compared the LFH with SIFT (local method) and EHD (global method) via storage capacity, extraction and retrieval time along with accuracy.