• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.76-82
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• 2017

An image hash, a discriminative and robust summary of an image, should be robust against quality-preserving signal processing steps, while being pairwise independent for perceptually different inputs. In order to improve the hash matching performance, this paper proposes a probabilistic dissimilarity matching. Instead of extracting the binary hash from the query image, we compute the probability that the intermediate hash vector of the query image belongs to each quantization bin, which is referred to as soft quantization binning. The probability is used as a weight in comparing the binary hash of the query with that stored in a database. A performance evaluation over sets of image distortions shows that the proposed probabilistic matching method effectively improves the hash matching performance as compared with the conventional Hamming distance.

• Journal of Power Electronics
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• v.16 no.1
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• pp.102-110
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• 2016

Contactless power transfer technology is gaining increasing attention in city transportation applications because of its high mobility and flexibility in charging and its commensurate power level with conductive power transfer method. In this study, an inductively coupled contactless charging system for a 48 V light electric vehicle is proposed. Although this study does not focus on system efficiency, the generic problems in an inductively coupled contactless power transfer system without ferromagnetic structure are discussed. An active load matching method is also proposed to control the power transfer on the receiving side through a load matching converter. Small signal modeling and linear control technology are applied to the load matching converter for port voltage regulation, which effectively controls the power flow into the load. A prototype is built, and experiments are conducted to reveal the intrinsic characteristics of a series-series resonant inductive power charger in terms of frequency, air gap length, power flow control, coil misalignment, and efficiency issues.

• The KIPS Transactions:PartB
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• v.13B no.6 s.109
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• pp.579-584
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• 2006

This paper proposes a nonlinear template matching measure, called counting measure, as a signal detection measure that is defined as the number of on pixels in the spot area. It is applied to classify probes for an on-off type DNA chip, where each probe spot is classified as hybridized or not. The counting measure also incorporates the maximum response search method, where the expected signal is obtained by taking the maximum among the measured responses of the various positions and sizes of the spot template. The counting measure was compared to existing signal detection measures such as the normalized correlation and the median for 2390 patient samples tested on the human papiliomavirus (HPV) DNA chip. The counting measure performed the best regardless of whether or not the maximum response search method was used. The experimental results showed that the counting measure combined with the positional search was the most preferable.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.807-815
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• 2019

In this paper, we design a power amplifier to support quad-band in wireless communication devices using RF CMOS 180-nm process. The proposed power amplifier consists of low-band 0.9, 1.8, and 2.4 GHz and high-band 5 GHz. We proposed a structure that can support each input matching network without using a switch. For maximum linear output power, the output matching network was designed for impedance conversion to the power matching point. The fabricated quad-band power amplifier was verified using modulation signals. The long-term evolution(LTE) 10 MHz modulated signal was used for 0.9 and 1.8 GHz, and the measured output power is 23.55 and 24.23 dBm, respectively. The LTE 20 MHz modulated signal was used for 1.8 GHz, and the measured output power is 22.24 dBm. The wireless local area network(WLAN) 802.11n modulated signal was used for 2.4 GHz and 5.0 GHz. We obtain maximum linear output power of 20.58 dBm at 2.4 GHz and 17.7 dBm at 5.0 GHz.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.131-147
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• 2020

RFID (Radio Frequency Identification) identifies a specific object by radio signals. As the tag provides a unique ID for the purpose of identification, RFID technology effectively solves the ambiguity and occlusion problem that challenges the laser or camera-based approach. This paper proposes an approach to track a moving object based on the integration of RFID and laser ranging information using a particle filter. To be precise, we split laser scan points into different clusters which contain the potential moving objects and calculate the radial velocity of each cluster. The velocity information is compared with the radial velocity estimated from RFID phase difference. In order to achieve the positioning of the moving object, we select a number of K best matching clusters to update the weights of the particle filter. To further improve the positioning accuracy, we incorporate RFID signal strength information into the particle filter using a pre-trained sensor model. The proposed approach is tested on a SCITOS service robot under different types of tags and various human velocities. The results show that fusion of signal strength and laser ranging information has significantly increased the positioning accuracy when compared to radial velocity matching-based or signal strength-based approaches. The proposed approach provides a solution for human machine interaction and object tracking, which has potential applications in many fields for example supermarkets, libraries, shopping malls, and exhibitions.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.671-674
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• 2005

Atmospheric correction over the ocean part is more important than that over the land because the signal from the ocean is very small about one tenth of that reflected from land. In this study, the Spectral Shape Matching Method (SSMM) developed by Ahn and Shanmugam (2004) is evaluated using Landsat imagery acquired over the highly turbid Saemangeum Coastal Area. The result of SSMM is compared with COST model developed by Chavez (1991 and 1997). In principle, SSMM is simple and easy to implement on any satellite imagery, relying on both field and image properties. To assess the potential use of these methods, several field campaigns were conducted in the Saemangeum coastal area corresponding with Landsat-7 satellite's overpass on 29 May 2005. In-situ data collected from the coastal waters of Saemangeum using optical instruments (ASD field spectroradiometer) consists of ChI, Ap, SS, aooM, F(d). In order to perform SSMM, we use the in-situ water-leaving radiance spectra from clear oceanic waters to estimate the the path radiance from total signal recorded at the top of the atmosphere (TOA), due to the reason that the shape of clear water-leaving radiance spectra is nearly stable than turbid water-leaving radiance spectra. The retrieved water-leaving radiance after subtraction of path signal from TOA signal in this way is compared with that estimated by COST model. The result shows that SSMM enabled retrieval of water-leaving radiance spectra that are consistent with in-situ data obtained from Saemangeum coastal waters. The COST model yielded significantly high errors in these areas.

• Journal of Satellite, Information and Communications
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• v.1 no.1
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• pp.59-64
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• 2006

The broadband power detector for power amplitude envelope detection of the direct-conversion Six-port output signal was designed and implemented in this paper. The power detector should be linearly operated to produce the linear amplitude and phase signal for input RF signals in required broadband frequency range. The power detector should be designed under conditions of matching circuit with low VSWR, which protect unbalanced phase signal from reflection signal due to mismatch between the output port of a six-port and the input port of a power detector. The designed power detectors, which were implemented in L-band with 50 ohm matching and Ku-band with multiple LC matching circuits and isolator, respectively, were analyzed in viewpoints of the utilization as a power detector of direct conversion Six-port. The dynamic range of designed power detectors were also measured and rvaluated as a power detector of Six-port circuit.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.1-8
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• 2015

This paper presents a Electrocardiogram(ECG) identification method using adaptive weight based on Least Mean Square Error(LMSE) optimization. With a preprocessing for noise suppression, we extracts the average ECG signal and its standard deviation at every time instant. Then the extracted information is stored in database. ECG identification is achieved by matching an input ECG signal with the information in database. In computing the matching scores, the standard deviation is used. The scores are computed by applying adaptive weights to the values of the input signal over all time instants. The adaptive weight consists of two terms. The first term is the inverse of the standard deviation of an input signal. The second term is the proportional one to the standard deviation between user SAECGs stored in the DB. Experimental results show up to 100% recognition rate for 32 registered people.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.55-58
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• 1997

In this paper, we study a signal processing method which extracts each MUAP(motor unit action potential) from EMG(Electromyogram) interference pattern or clinical diagnostic purposes. First of all, differential digital filtering is selected or eliminating the spike components of the MUAP's from the background noise. And, the algorithm identifies the spikes over the certanin threshold by template matching in frequency domain. After missing or false firing actor is cut off at the IPI(inter pulse interval) histogram, we averages the MUAP waveforms from the raw signal using the identified spikes as triggers, and Finally, measures their amplitudes, durations, and numbers of phases. Specially, We introduce algorithm performed by template matching in the frequency domain. A typical 3-s signal recorded from the biceps brachii muscle using a conventional needle electrode during a isometric contraction is used. Finally, the method decomposed five simultaneous active MUAP's from original EMG signal.

• Tribology and Lubricants
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• v.37 no.5
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• pp.164-171
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• 2021

Ultrasonic sensors show various reception characteristics based on the density of the measurement medium; hence, they are used in various fields to benefit from the characteristics of ultrasonic signals. In this study, the reception characteristics according to the thickness of the first matching layer are compared and analyzed for application to gas tank microleak detection. Accordingly, three types of sensors are manufactured with varying thicknesses of the first matching layer, namely 4.8 mm, 5.1 mm, and 5.5 mm; further, a direct measurement method is used wherein the sensor is attached to the inside of the chamber. Experiments are conducted to observe the phase change due to microleakage, which is the most linear in the sensor with the 4.8 mm thick first matching layer. This is assumed to be the result of stable signal transmission and reception with little phase deviations over time because the first matching layer is closest to the ultrasonic wavelength. The other sensors show nonlinear results with increasing thickness of the first matching layer. Through this study, it is found that appropriately selecting the thickness of the first matching layer of the ultrasonic sensor can greatly influence sensor reliability.