• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.97-102
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• 2016

The UFMC(Universal Filtered Multi-Carrier) is one of multi-carrier transmission technique as a candidate of transmission method for the recent 5G communication system. The UFMC can be considered as the system which has both the advantages of OFDM(Orthogonal Frequency Division Multiplex) and the simplicity of FBMC(Filter Bank Multi-Carrier). CFO(Carrier Frequency Offset) causes the problem to lower the BER performance due to a mismatch between the sub-carriers in multi-carrier transmission scheme. The effect of CFO on UFMC is not greater than the OFDM. But it still degrades the system performance caused by interference between the sub-band. In this paper, we analyze the SNR degradation due to changes in the value of EsNo and CFO on UFMC system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2879-2899
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• 2021

The tone reservation (TR) scheme is an attractive method to reduce peak-to-average power ratio (PAPR) in the filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) systems. However, the high PAPR of FBMC signal will severely degrades system performance. To address this issue, a cyclic shift based TR (CS-TR) scheme with embedding side information (SI) is proposed to reduce the PAPR of FBMC signals. At the transmitter, four candidate signals are first generated based on cyclic shift of the output of inverse discrete Fourier transform (IDFT), and the SI of the selected signal with minimum peak power among the four candidate signals is embedded in sparse symbols with quadrature phase-shift keying constellation. Then, the TR weighted by optimal scaling factor is employed to further reduce PAPR of the selected signal. At the receiver, a reliable SI detector is presented by determining the phase rotation of SI embedding symbols, and the transmitted data blocks can be correctly demodulated according to the detected SI. Simulation results show that the proposed scheme significantly outperforms the existing TR schemes in both PAPR reduction and bit error rate (BER) performances. In addition, the proposed scheme with detected SI can achieve the same BER performance compared to the one with perfect SI.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.350-364
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• 2022

Traditionally, in multi-user multi-carrier systems, the neighboring subband will be gapped by one subcarrier, which is set as guard band to reduce multiple access interference (MAI) between neighboring subbands. The empty subcarrier for guard band will degrade the spectral efficiency of the whole system. In order to enhance the spectral efficiency of multi-user filter bank multiple carrier (FBMC) systems, a new subband allocation method is introduced, in which the neighboring subband is gapped by half subcarrier instead of one subcarrier. Meanwhile, in order to implement the proposed resource allocation scheme, an optimized FBMC prototype filter is designed to decrease the inter-subband interference to the neighboring subband. The detailed simulations about the comparison between the proposed spectrum assignment and traditional FBMC are given, as well as the performance in the different interference scenarios. The simulation results show that the combination of the proposed spectrum assignment scheme and the optimized filter has better performance compared to the traditional scheme. The proposed scheme can be used in the system which serves massive users to get higher spectrum efficiency.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.3-17
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• 2011

Pipelines of processor have been growing deeper and issue widths wider over the years. If this trend continues, branch misprediction penalty will become very high. Branch misprediction is the single most significant performance limiter for improving processor performance using deeper pipelining. Therefore, more accurate branch predictor becomes an essential part of modem processors for FAFF(Food, Agriculture, Forestry, Fisheries)Information Processing. In this paper, we propose a branch prediction mechanism, using variable length history, which predicts using a bank having higher prediction accuracy among predictions from five banks. Bank 0 is a bimodal predictor which is indexed with the 12 least significant bits of the branch PC. Banks 1,2,3 and 4 are predictors which are indexed with different global history bits and the branch PC. In simulation results, the proposed mechanism outperforms gshare predictors using fixed history length of 12 and 13, up to 6.34% in prediction accuracy. Furthermore, the proposed mechanism outperforms gshare predictors using best history lengths for benchmarks, up to 2.3% in prediction accuracy.

• Atmosphere
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• v.34 no.2
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• pp.107-121
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• 2024

In this study, we empirically analyzed the impact of physical risks due to climate change on the soundness and operational performance of the financial industry by combining economics and climatology. Particularly, unlike previous studies, we employed the Seasonal-Trend decomposition using LOESS (STL) method to extract trends of climate-related risk variables and economic-financial variables, conducting a two-stage empirical analysis. In the first stage estimation, we found that the delinquency rate and the Bank for International Settlement (BIS) ratio of commercial banks have significant negative effects on the damage caused by natural disasters, frequency of heavy rainfall, average temperature, and number of typhoons. On the other hand, for insurance companies, the damage from natural disasters, frequency of heavy rainfall, frequency of heavy snowfall, and annual average temperature have significant negative effects on return on assets (ROA) and the risk-based capital ratio (RBC). In the second stage estimation, based on the first stage results, we predicted the soundness and operational performance indicators of commercial banks and insurance companies until 2035. According to the forecast results, the delinquency rate of commercial banks is expected to increase steadily until 2035 under assumption that recent years' trend continues until 2035. It indicates that banks' managerial risk can be seriously worsened from climate change. Also the BIS ratio is expected to decrease which also indicates weakening safety buffer against climate risks over time. Additionally, the ROA of insurance companies is expected to decrease, followed by an increase in the RBC, and then a subsequent decrease.

• Journal of computational fluids engineering
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• v.15 no.1
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• pp.17-23
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• 2010

Performance improvements of the heat recovery steam generator(HRSG) can be achieved by improving the flow distribution of exhaust gases for a various type of different equipments. A number of design parameters are systematically investigated and their effects on an index of velocity deviation established. The parameters include the three shape of the transition duct and the wide range of the guide vane angles. The numerical results clearly reveal feature of the flow pattern in the transition duct, velocity deviation and pressure drop at tube bank part.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.285-289
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• 2009

In this paper, we propose to research the dynamic Matlab/Simulink model of supercapacitor bank(SCB) for a microgrid application. We demonstrated that this model id sufficient to design the control system of entire power storage system, SCB, the chopper and grid connected converter. The proposed dynamic model is simulated with the help of Matlab/$Simulink^{TK}$ in the MTG/PC/SCB hybrid energy system. The study results show that SCB have a good performance to curb power fluctuation in building microgrid application.

• Knowledge Management Research
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• v.17 no.3
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• pp.227-248
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• 2016

Customer satisfaction dominates research on customer-firm performance relationships; however, with a few exceptions, the authors of most prior studies did not examine the possibility that an organizations' customer relationship management can increase its knowledge management. Building on previous literature of information processing theory and transaction cost perspective, this paper investigates the effect of various characteristics of customer relationship an organization cultivates on its own innovativeness. Specifically, we identify closeness, communication, sympathy as three critical components of managing customer relationship. Data from a multi-informant survey conducted to 442 organizations in Korean bank industry show that an organization's relationship with its customers has significant effects on its innovativeness. This study highlights the importance of customer relationship in terms of enhancing innovations, and helps to explain interactive effects among customer relationship, organizational learning, and innovativeness.

• Journal of information and communication convergence engineering
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• v.1 no.4
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• pp.209-212
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• 2003

In this paper, we proposed new speech feature parameter through parts-based feature extraction of speech spectrum using Non-Negative Matrix Factorization (NMF). NMF can effectively reduce dimension for multi-dimensional data through matrix factorization under the non-negativity constraints, and dimensionally reduced data should be presented parts-based features of input data. For speech feature extraction, we applied Mel-scaled filter bank outputs to inputs of NMF, than used outputs of NMF for inputs of speech recognizer. From recognition experiment result, we could confirm that proposed feature parameter is superior in recognition performance than mel frequency cepstral coefficient (MFCC) that is used generally.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.481-483
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• 1989

This paper is concentrated on the recognition of Korean Digits. The speech signals of each of digits are fed into computer through the 18 bandpass filters, AD converter. Spectrum input data are analyzed and used. BASIC program language is used for recognition performance and the result of recognition is outputed to computer screen and printer. In this paper, the strength and weakness of filter-bank analysis method is described and the technique of real-time recognition is argued. In this experiment, Ratio of recognition for speaker dependent recognition was about 97% and recognition time was also satisfied. Therefore, A way of speaker independent recognition will be presented and using for special communication in the future.