• Title/Summary/Keyword: detection technique

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Automatic Generation of the Personal 3D Face Model (3차원 개인 얼굴 모델 자동 생성)

  • Ham, Sang-Jin;Kim, Hyoung-Gon
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.1
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    • pp.104-114
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    • 1999
  • This paper proposes an efficient method for the automatic generation of personalized 3D face model from color image sequence. To detect a robust facial region in a complex background, moving color detection technique based on he facial color distribution has been suggested. Color distribution and edge position information in the detected face region are used to extract the exact 31 facial feature points of the facial description parameter(FDP) proposed by MPEG-4 SNHC(Synthetic-Natural Hybrid Coding) adhoc group. Extracted feature points are then applied to the corresponding vertex points of the 3D generic face model composed of 1038 triangular mesh points. The personalized 3D face model can be generated automatically in less then 2 seconds on Pentium PC.

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Preparation of Metal-p-aminobenzyl-DOTA Complex Using Magnetic Particles for Bio-tagging in Laser Ablation ICP-MS

  • Yoon, S.Y.;Lim, H.B.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3665-3670
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    • 2012
  • Metal-p-$NH_2$-Bn-DOTA (paraammionobenzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid: ABDOTA) complex was synthesized and purified for bio-tagging to quantify biological target materials using laser ablation (LA)-ICP-MS. Since the preparation of a pure and stable tagging complex is the key procedure for quantification, magnetic particles were used to purify the synthesized metal-ABDOTA complex. The magnetic particles immobilized with the complex attracted to a permanent magnet, resulting in fast separation from free un-reacted metal ions in solution. Gd ions formed the metal-complex with a higher yield of 64.3% (${\pm}3.9%$ relative standard deviation (RSD)) than Y ions, 52.3% (${\pm}2.5%$ RSD), in the pH range 4-7. The complex bound to the magnetic particles was released by treatment with a strong base, of which the recovery was 81.7%. As a reference, a solid phase extraction (SPE) column packed with Chelex-100 resin was employed for separation under similar conditions and produced comparable results. The tagging technique complemented polydimethylsiloxane (PDMS) microarray chip sampling in LA-ICP-MS, allowing determination of small sample volumes at high throughputs. For application, immunoglobulin G (IgG) was immobilized on the pillars of PDMS microarray chips and then tagged with the prepared Gd complex. IgG could then be determined through measurement of Gd by LA-ICP-MS. A detection limit of 1.61 ng/mL (${\pm}0.75%$ RSD) for Gd was obtained.

Guided Wave THz Spectroscopy of Explosive Materials

  • Yoo, Byung-Hwa;Kang, Seung-Beom;Kwak, Min-Hwan;Kim, Sung-Il;Kim, Tae-Yong;Ryu, Han-Cheol;Jun, Dong-Suk;Paek, Mun-Cheol;Kang, Kwang-Yong;Chung, Dong-Chul
    • Journal of electromagnetic engineering and science
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    • v.11 no.1
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    • pp.42-50
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    • 2011
  • One of the important applications of THz time-domain spectroscopy (TDS) is the detection of explosive materials through identification of vibrational fingerprint spectra. Most recent THz spectroscopic measurements have been made using pellet samples, where disorder effects contribute to line broadening, which results in the merging of individual resonances into relatively broad absorption features. To address this issue, we used the technique of parallel plate waveguide (PPWG) THz-TDS to achieve sensitive characterization of three explosive materials: TNT, RDX, and HMX. The measurement method for PPWG THz-TDS used well-established ultrafast optoelectronic techniques to generate and detect sub-picosecond THz pulses. All materials were characterized as powder layers in 112 ${\mu}m$ gaps in metal PPWG. To illustrate the PPWG THz-TDS method, we described our measurement by comparing the vibrational spectra of the materials, TNT, RDX, and HMX, applied as thin powder layers to a PPWG, or in conventional sample cell form, where all materials were placed in Teflon sample cells. The thin layer mass was estimated to be about 700 ${\mu}g$, whereas the mass in the sample cell was ~100 mg. In a laboratory environment, the absorption coefficient of an explosive material is essentially based on the mass of the material, which is given as: ${\alpha}({\omega})=[ln(I_R({\omega})/I_S({\omega}))]m$. In this paper, we show spectra of 3 different explosives from 0.2 to 2.4 THz measured using the PPWG THz-TDS.

A Study on the Improvement of DTW with Speech Silence Detection (음성의 묵음구간 검출을 통한 DTW의 성능개선에 관한 연구)

  • Kim, Jong-Kuk;Jo, Wang-Rae;Bae, Myung-Jin
    • Speech Sciences
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    • v.10 no.4
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    • pp.117-124
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    • 2003
  • Speaker recognition is the technology that confirms the identification of speaker by using the characteristic of speech. Such technique is classified into speaker identification and speaker verification: The first method discriminates the speaker from the preregistered group and recognize the word, the second verifies the speaker who claims the identification. This method that extracts the information of speaker from the speech and confirms the individual identification becomes one of the most efficient technology as the service via telephone network is popularized. Some problems, however, must be solved for the real application as follows; The first thing is concerning that the safe method is necessary to reject the imposter because the recognition is not performed for the only preregistered customer. The second thing is about the fact that the characteristic of speech is changed as time goes by, So this fact causes the severe degradation of recognition rate and the inconvenience of users as the number of times to utter the text increases. The last thing is relating to the fact that the common characteristic among speakers causes the wrong recognition result. The silence parts being included the center of speech cause that identification rate is decreased. In this paper, to make improvement, We proposed identification rate can be improved by removing silence part before processing identification algorithm. The methods detecting speech area are zero crossing rate, energy of signal detect end point and starting point of the speech and process DTW algorithm by using two methods in this paper. As a result, the proposed method is obtained about 3% of improved recognition rate compare with the conventional methods.

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Design of a Built-In Current Sensor for CMOS IC Testing (CMOS 집적회로 테스팅을 위한 내장형 전류 감지 회로 설계)

  • Kim, Tae-Sang;Hong, Seung-Ho;Kwak, Chul-Ho;Kim, Jeong-Beam
    • Journal of IKEEE
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    • v.9 no.1 s.16
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    • pp.57-64
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    • 2005
  • This paper presents a built-in current sensor(BICS) that detects defects in CMOS integrated circuits using the current testing technique. This circuit employs a cross-coupled connected PMOS transistors, it is used as a current comparator. The proposed circuit has a negligible impact on the performance of the circuit under test (CUT) and high speed detection time. In addition, in the operation of the normal mode, the BlCS does not have dissipation of extra power, and it can be applied to the deep submicron process. The validity and effectiveness are verified through the HSPICE simulation on circuits with defects. The area overhead of a BlCS versus the entire chip is about 9.2%. The chip was fabricated with Hynix $0.35{\mu}m$ 2-poly 4-metal N-well CMOS standard technology.

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A Fault Diagnosis Technique of an Inverter-fed PMSM under Winding Shorted Turn and Inverter Switch Open Fault (권선 단락 및 스위치 개방 고장 시의 인버터 구동 영구자석 동기전동기의 고장 진단 기법)

  • Kim, Kyeong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.5
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    • pp.94-105
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    • 2010
  • To detect faults in an inverter-fed permanent magnet synchronous motor (PMSM) drive under the circumstance having faults in a stator winding and inverter switch, an on-line basis fault detecting scheme during operation is presented. The proposed scheme is achieved by monitoring the second-order harmonic component in q-axis current and the fault is detected by comparing these components with those in normal conditions. The linear interpolation method is employed to determine the harmonic data in normal operating conditions. As soon as the fault is detected, the operating mode is changed to identify a fault type using the phase current waveform. To verify the effectiveness of the proposed fault detecting scheme, a test motor to allow inter-turn short in the stator winding has been built. The entire control algorithm is implemented using DSP TMS320F28335. Without requiring an additional hardware, the fault can be effectively detected by the proposed scheme during operation so long as the steady-state condition is satisfied.

Abnormal current-voltage characteristics of $SnO_2$ oxide semiconductor and their application to gas sensors ($SnO_2$ 산화물 반도체의 비정상적 전류 - 전압 특성과 가스센서로의 응용)

  • Lee Kyu-chung;Yoon Ho-Kun;Hur Chang-Wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.7
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    • pp.1436-1441
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    • 2004
  • Abnormal current-voltage characteristics of an oxide semiconductor have been investigated and a novel method of detecting reducing gases utilizing self-heating mechanism of sensing layer without an additional heater has been developed. Planar-type sensors based on WO3-doped SnO2 were fabricated using a screen-printing technique. The applied voltage across the sensing layer caused heating of the sensing layer and the current abruptly varied upon exposure to a gas mostly as a result of surface reactions. A unique and fascinating aspect of the gas sensing scheme is that no additional heater is necessary for detection. The new sensing method has been applied to C2H5OH gas in this preliminary work.

Simulation of Radiation Imaging based on the Scanning of Pin-hole Stereo Vision Sensors (핀홀 스테레오 비전 센서의 공간 스캔을 통한 방사선의 영상화 시뮬레이션)

  • Park, Soon-Yong;Baek, Seung-Hae;Choi, Chang-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.7
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    • pp.1671-1680
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    • 2014
  • There are always much concern about the leakage of radiation materials in the event of dismantle or unexpected accident of nuclear power plant. In order to remove the leakage of radiation materials, appropriate dispersion detection techniques for radiation materials are necessary. However, because direct handling of radiation materials is highly restricted and risky, developing radiation-related techniques needs computer simulation in advance to evaluate the feasibility. In this paper, we propose a radiation imaging technique which can acquire 3D dispersion information of radiation materials and tested by simulation. Using two virtual 1D radiation sensors, we obtain stereo radiation images and acquire the 3D depth to virtual radiation materials using stereo disparity. For point and plane type virtual radiation materials, the possibility of the acquisition of stereo radiation image and 3D information are simulated.

Optimal Machine Learning Model for Detecting Normal and Malicious Android Apps (안드로이드 정상 및 악성 앱 판별을 위한 최적합 머신러닝 기법)

  • Lee, Hyung-Woo;Lee, HanSeong
    • Journal of Internet of Things and Convergence
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    • v.6 no.2
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    • pp.1-10
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    • 2020
  • The mobile application based on the Android platform is simple to decompile, making it possible to create malicious applications similar to normal ones, and can easily distribute the created malicious apps through the Android third party app store. In this case, the Android malicious application in the smartphone causes several problems such as leakage of personal information in the device, transmission of premium SMS, and leakage of location information and call records. Therefore, it is necessary to select a optimal model that provides the best performance among the machine learning techniques that have published recently, and provide a technique to automatically identify malicious Android apps. Therefore, in this paper, after adopting the feature engineering to Android apps on official test set, a total of four performance evaluation experiments were conducted to select the machine learning model that provides the optimal performance for Android malicious app detection.

Simplified PAR Reduction Technique for MIMO-OFDM System (MIMO-OFDM 시스템에서 간략화된 PAR 감쇄 기법)

  • Song Hyoung-Kyu;Kook Hyung-Joon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.12C
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    • pp.1181-1185
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    • 2005
  • A combining of MIMO signal processing with OFDM is regarded as a promising solution of enhancing the performance of next generation wireless system. Therefore, in this paper, an OFDM-based wireless system employing layered space-time architecture is considered for a high-rate transmission. In the MIMO-OFDM system, we evaluate the PAR performance using the SLM approaches. The investigated SLM scheme for MIMO-OFDM signals selects the transmitted sequence with lowest average PAR over all transmitting antennas and retrieves the side information very accurately at the expense of a slight degradation of the PAR performance. The low probability of false side information can improve the overall detection performance of the MIMO-OFDM system with erroneous side information compared to the ordinary SLM approache, respectively. Also, we provide closed form of the average BER performance in MIMO-OFDM system using analytic approach.