• Smart Media Journal
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• v.9 no.4
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• pp.97-101
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• 2020

Using passive electric field sensor which operates in non-contact mode, we can measure the electric potential induced from the change of electric charges on a sensor caused by the movement of human body or hands. In this study, we propose a new method, which utilizes PLN induced to the sensor around the moving object, to detect one's hand movement and extract gesture frames from the detected signals. Signals from the EPS sensors include a large amount of power line noise usually existing in the places such as rooms or buildings. Using the fact that the PLN is shielded in part by human access to the sensor, signals caused by motion or hand movement are detected. PLN consists mainly of signals with frequency of 60 Hz and its harmonics. In our proposed method, signals only 120 Hz component in frequency domain are chosen selectively and exclusively utilized for detection of hand movement. We use FFT to measure a spectral-separated frequency signal. The signals obtained from sensors in this way are continued to be compared with the threshold preset in advance. Once motion signals are detected passing throng the threshold, we determine the motion frame based on period between the first threshold passing time and the last one. The motion detection rate of our proposed method was about 90% while the correct frame extraction rate was about 85%. The method like our method, which use PLN signal in order to extract useful data about motion movement from non-contact mode EPS sensors, has been rarely reported or published in recent. This research results can be expected to be useful especially in circumstance of having surrounding PLN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3C
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• pp.302-313
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• 2010

In this paper, we propose an enhanced AGC (Automatic Gain Control) structure and P-SCH detection method for initial cell search in 3GPP (3rdGenerationPartnershipProject) LTE (Long Term Evolution) FDD(Frequency Division Duplex) / TDD (Time Division Duplex) dual mode system. Since TDD frame structure consists of uplink subframe and downlink subframe, conventional AGC structure causes P-SCH detection performance degradation by increase of AGC variation due to signal power difference between uplink and downlink subframe. Also, P-SCH detection performance is degraded by distortion of P-SCH correlation characteristic in frequency offset and multipath fading channel environments. Therefore, we propose an AGC structure which can minimize P-SCH detection performance degradation with stable operation in 3GPP LTE TDD mode as well as FDD mode. Also we propose a P-SCH detection method which can reduce distortion of correlation chareteristics in frequency offset and multipath fading environments and obtain good P-SCH detection performance. Simulation results show that the proposed AGC structure and P-SCH detection method have stable AGC operation and excellent P-SCH detection performance for 3GPP LTE TDD / FDD dual mode downlink receiver in various channel environments.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.94-105
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• 2001

Background : Examining the biological susceptibility of Mycobacterium tuberculosis to pyrazinamide (PZA) in vitro is very difficult as PZA is inactive under normal culture conditions. The biological susceptibility test, an enzyme assay for Pzase activity, and a genetic test for pncA gene mutations, were performed in order to predict PZA resistance. Methods : 28 cultured clinical isolates of Mycobacterium tuberculosis were tested. The biological susceptibility was performed by the absolute concentration method using Lowenstein-Jensen media. The PZase activity was tested by means of Wayne's method. A 710-bp region includes the entire open reading frame of pncA was amplified and sequenced. Results : All six strains with positive PZase activity exhibited no pncA mutations with one strain showing a false resistance in the biological susceptibility test. Among the 22 strains with no PZase activity, 21 exhibited showed pncA mutations. In the biological susceptibility test, 20 strains were resistant, and one was susceptible, and the other flied to test. The mutation types varied with ten missense, one silent and one nonsense mutation 1 slipped-strand mispairing, and 6 frameshift mutations. Three strains had an adenine to guanine mutation at position -11 upstream of the start codon. Conclusion : The mutation at the pncA promotor region is frequent at -11 upstream position. Automatic sequencing of pncA is a useful tool for rapid and accurate detection of PZA resistant M. tuberculosis, and for demonstrating the epidemiological relatedness of the PZA resistant M. tuberculosis strains.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.169-179
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• 2013

Change detection algorithms take two image frames and return the locations of newly introduced objects which cause differences between the images. This paper presents a new change detection method, which classifies intensity changes due to introduced objects, reflected light and shadow from the objects to their neighborhood, and the noise, and exactly localizes the introduced objects. For classification and localization, first we analyze the histogram of the intensity difference between two images, and estimate multiple threshold values. Second we estimate candidate object boundaries using the gradient difference between two images. Using those threshold values and candidate object boundaries, we segment the frame difference image into multiple regions. Finally we classify whether each region belongs to the introduced objects or not using textures in the region. Experiments show that the proposed method exactly localizes the objects in various scenes with different lighting.

• Clean Technology
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• v.11 no.2
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• pp.69-74
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• 2005

A metal ion detector with a submicron size electrode was fabricated by field-induced AFM oxidation. The square frame of the mesa pattern was functionalized by APTES for the metal ion detection, and the remaining portion was used as an electrode by the self-assembly of MPTMS for Au metal deposition. The conductance changed with the quantity of adsorbed copper ions, due to electron tunneling between the mobile and surface electrodes. The smaller electrode has a lower limit of detection due to the enhancement in electron tunneling through metal ions that are adsorbed between the conductive-tip (mobile) and the surface (fixed) electrode. This two-electrode system immobilized with different functional groups was successfully used in the selective adsorption and detection of target materials.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.129-136
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• 2020

In this paper, we propose a thermal imagery-based object detection algorithm for low-light level nighttime surveillance system. Many features selected by Haar-like feature selection algorithm and existing Adaboost algorithm are often vulnerable to noise and problems with similar or overlapping feature set for learning samples. It also removes noise from the feature set from the surveillance image of the low-light night environment, and implements it using the lightweight extended Haar feature and adaboost learning algorithm to enable fast and efficient real-time feature selection. Experiments use extended Haar feature points to recognize non-predictive objects with motion in nighttime low-light environments. The Adaboost learning algorithm with video frame 800*600 thermal image as input is implemented with CUDA 9.0 platform for simulation. As a result, the results of object detection confirmed that the success rate was about 90% or more, and the processing speed was about 30% faster than the computational results obtained through histogram equalization operations in general images.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.384-390
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• 2016

It is important to have a pipeline leak-detection system that determines the presence of a leak and quickly identifies its location. Current leak detection methods use a acoustic emission sensors, microphone arrays, and camera images. Recently, many researchers have been focusing on using cameras for detecting leaks. The advantage of this method is that it can survey a wide area and monitor a pipeline over a long distance. However, conventional methods using camera monitoring are unable to target an exact leak location. In this paper, we propose a method of detecting leak locations using leak-detection results combined with multi-frame analysis. The proposed method is verified by experiment.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.20-29
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• 2013

The compression of video data is intended for real-time transmission of band-limited channels. Compressed video bit-streams are very sensitive to transmission error. If we lose packets or receive them with errors during transmission, not only the current frame will be corrupted, but also the error will propagate to succeeding frames due to the spatio-temporal predictive coding structure of sequences. Error detection and concealment is a good approach to reduce the bad influence on the reconstructed visual quality. To increase concealment efficiency, we need to get some more accurate error detection algorithm. In this paper, We hide specific data into the motion vector difference of each macro-block, which is obtained from the procedure of inter prediction mode in H.264/AVC. Then, the location of errors can be detected easily by checking transmitted specific data in decoder. We verified that the proposed algorithm generates good performances in PSNR and subjective visual quality through the computer simulation by H.324M mobile simulation tool.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1577-1585
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• 1999

In this paper, we propose detection methods for gradual scene changes such as dissolve, pan, and zoom. The proposal method to detect a dissolve region uses scene features based on spatial statistics of the image. The spatial statistics to define shot boundaries are derived from squared means within each local area. We also propose a method of the camera motion detection using four representative motion vectors in the background. Representative motion vectors are derived from macroblock motion vectors which are directly extracted from MPEG streams. To reduce the implementation time, we use DC sequences rather than fully decoded MPEG video. In addition, to detect the gradual scene change region precisely, we use all types of the MPEG frames(I, P, B frame). Simulation results show that the proposed detection methods perform better than existing methods.

• Journal of Broadcast Engineering
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• v.19 no.3
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• pp.296-306
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• 2014

This paper addresses a problem of non-dialog section detection for the DVS authoring, the goal of which is to find meaningful section from the broadcasting audio, where audio description can be inserted. The broadcasting audio involves the presence of various sounds so that it first discriminates between speech and non-speech for each audio frame. Proposed method jointly exploits the inter-channels structure and speech source characteristics of the broadcasting audio whose number of channel is stereo. Also, rule based post-processing is finally applied to detect the non-dialog section whose length is appropriate for audio description. Proposed method provides more accurate detection compared to conventional method. Experimental results on real broadcasting contents show that qualitative superiority of the proposed method.