• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.89-95
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• 2020

Recently, studies are being conducted to recognize a sketch image of a GUI (Graphical User Interface) based on a deep learning and to make it into a code implemented in an application. UI / UX designers can communicate with developers through storyboards when developing mobile applications. However, UI / UX designers can create different widgets for ambiguous widgets. In this paper, we propose an automatic UI detection method using symbol markers to improve the accuracy of DNN (Deep Neural Network) based UI identification. In order to evaluate the performance with or without the symbol markers, their accuracy is compared. In order to improve the accuracy according to of the symbol marker, the results are analyzed when the shape is a circle or a parenthesis. The use of symbol markers will reduce feedback between developer and designer, time and cost, and reduce sketch image UI false positives and improve accuracy.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.58-68
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• 2000

In this paper we introduce the correlation-aided distributed sample acquisition (CDSA) scheme for fast cell search in IMT-2000 W-CDMA cellular system. The proposed scheme incorporates the state symbol correlation process into the comparison-correction based synchronization process of the original DSA scheme to enable fast acquisition even under very poor channel environment. for its realization, each mobile station (MS) has to store in its memory a set of state sample sequences. which are determined by the long-period scrambling sequences used in the system and the sampling interval of the state samples. CDSA based cell search is carried out in two stages : First, the MS first acquires the slot timing by using the primary synch code (PSC) and then identifies the igniter code which conveys the state samples of the current cell . Secondly. the MS identifies the scrambling code and frame timing by taking the comparison-correction based synchronization approach and, if the identification is not done satisfactorily within preset time. it initiates the state symbol correlation process which correlates the received symbol sequence with the pre-stored state sample sequences for a successful identification. As the state symbol SNR is relatively high. the state symbol correlation process enables reliable synchronization even in very low chip-SNR environment. Simulation results show that the proposed CDSA scheme outperforms the 3GPP 3-step approach, requiring the signal power of about 7 dB less for achieving the same acquisition time performance in low-SNR environments. Furthermore, it turns out very robust in the typical synchronization environment where large frequency offset exists.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.3
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• pp.41-50
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• 2010

In this paper, an area-efficient symbol detector is proposed for MIMO communication systems with two transmit and two receive antennas. The proposed symbol detector can support both the spatial multiplexing mode and spatial diversity mode for MIMO transmission technique, and shows the optimal maximum likelihood (ML) performance. Also, by sharing the hardware block with multi-stage pipeline structure and using the complex multiplier based on polar-coordinate，the complexity of the proposed architecture is dramatically decreased. The proposed symbol detector was designed in hardware description language (HDL) and implemented with Xilinx Virtex-5 FPGA. With the proposed architecture, the number of logic slices for the proposed symbol detection is 52490 and the number of DSP48s (dedicated multiplier) is 52, which are reduced by 35.3% and 85.3%, respectively, compared with the conventional architecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4563-4567
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• 2010

In this paper, the adaptive MPSAM is suggested in order to analyze and improve problems caused by the case of the impact of delay waves on Pilot Symbol Assisted Modulation (PSAM), a singular Pilot method. PSAM predicts and compensates amplitude and phases caused on fading channels, using the Pilot Symbol. In addition, the Basic method is not only analyzed but also grafted onto the suggested method properly; therefore, the performance could be improved. Comparing to the Basic method, the BER performance can be distinguished in case that the level of delay on delay waves with the suggested method goes below 0.7. On the other hand, the BER performance can be inferior due to a considerable effect of the adjacent symbol in the event that the level of delay on delay waves is worse. However, the BER performance is rather improved on the point where the level of delay on delay waves is serious because the Basic method uses reciprocal compensation. Hence, stable improvement can be expected in all areas which receive the influence of delay waves within one symbol once grafted onto the suggested method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.752-759
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• 2010

The low power consumption is the most important design factor for the In-Body communication system of WBAN. The conventional PSSK (Phase-Silence-Shift-keying) modulation technique can be regarded as an extension from PSK modulation. And this PSSK has better power efficiency than PSK modulation, and higher spectral efficiency than FSK modulation. PSSK modulation is to transmit two orthogonal symbols. The transmission power can be lowered because the symbol rate in signal period becomes half. BER performance is improved because transmission power is lower and the modulation symbol distance is widened. In addition, PSSK preserve the low-power and increase the data rate than FSK. In this paper, we analyzed existing PSSK and like to propose a new PSPM (Phase-Shift-Position-Modulation) modulation scheme. This PSPM is evaluated in terms of considered bandwidth efficiency and BER performance, compared with the PSSK. This PSPM modulation method transmits the information data by both PSK symbol data and symbol position data, so that we can significantly improve the power efficiency. New proposed PSPM method could be very useful for the In-body communication that requires the most power efficient system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2831-2838
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• 2014

This paper proposes the off-line handwritten flowchart symbol recognition algorithm by type and strength of a cross region of the straight line strokes that is extracted based the normalized dominant slope vectors. In the proposed algorithm, first of all, a connector symbol which consisted only curves is recognized by the special features, and the other symbols with straight line strokes are recognized by type and strength of a cross region, and that is extracted by extension of minimum bounding rectangle of the clusters of the normalized dominant slope vectors, and the straight line strokes of the symbols is extracted by the normalized dominant slope vectors. To confirm the validity of the proposed algorithm, the experiments are conducted for 10 different kinds of flowchart symbols that mainly used for computer program, and the number of symbols is 198. Experiment results were obtained the recognition rate of 99.5%, and the flowchart symbols is recognized correctly robust to variations, and then the proposed algorithm were found very effective for off-line handwritten flowchart symbol recognition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.2
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• pp.249-258
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• 1998

In land mobile communication, very extensive studies on pilot symbol assisted modulation (PSAM) have been made on fading compensation. This paper analyzes the effect of power amplifier nonlinearity on PSA-QAM with maximal ratio combining space diversity. In practical PSAM, information on fading is obtained through interpolation of the pilot symbols. We employed the interpolation filter which could minimize the average power of error and analyzed effects on the system performance of the number of filter taps, period of the pilot symbol frame, and the Doppler frequency. Nonlinear power amplifiers of class AB, B, and C were incorporated in the system models and their AM/AM and AM/PM characteristics were taken into account in the performance analysis. We showed the performance variations according to the types of the nonlinear power amplifiers in the AWGN and Rayleigh fading channels using nonlinear compensation technique, Cartesian Feedback Loop (CFB).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3482-3486
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• 2013

In the case of the Pilot Symbol Assisted Modulation (PSAM) method predicting and compensating amplitude and phases caused on fading channels, there can be severe performance deterioration by Doppler spread on fast fading channels. In this paper, the fading compensation method suggested so as to improve occurring problems as well as analyze them. Doppler spread is the major cause of the bit error rate(BER) performance deterioration. Compared to the existing PSAM method, the more performance deterioration occurs, the larger Doppler spread appears but performance shows well its less $10^{-2}BER$ performance than the existing PSAM method in the suggested method whereas the existing PSAM method has about $10^{-1}BER$ its considerable performance deterioration that caused by Doppler spread within a symbol cycle with the level of delay wave interference.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1042-1046
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• 2011

In this paper, we analyze the STO (Symbol Timing Offset) problem in conventional ZP-OFDM (Zero Padding-Orthogonal Frequency Division Multiplexing) systems and propose a robust ZP-OFDM system with bi-directional overlap-add scheme to overcome the problem. The proposed ZP-OFDM system is able to preserve the orthogonality between subcarriers and reduce the interference from other ZP-OFDM symbols due to the BOA scheme, which exploits both ZP intervals of the previous and the current ZP-OFDM symbols, even though serious STOs result from inaccurate symbol timing synchronization. Simulation results verify that the proposed ZP-OFDM system is superior to the conventional ZP-OFDM system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.12
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• pp.1-7
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• 2010

In this paper, the technique for obtaining diversity gain without increasing the antenna is proposed using symbol share in the OFDM systems. Proposed technique groups symbols which are mapped into different sub-carriers and these symbols are modulated by proposed constellation. Proposed constellation has the identical minimum distance with QPSK modulation constellation and obtain more frequency diversity gain. Also, proposed modulation scheme make it possible to increase data rate using subcarriers allocated symbols.