• Journal of the Korean Statistical Society
• /
• v.35 no.1
• /
• pp.105-114
• /
• 2006

In this paper we propose a simple and computationally attractive difference-based variance estimator in nonparametric regression models with multivariate predictors. We show that the estimator achieves $n^{-1/2}$ rate of convergence for regression functions with only a first derivative when d, the dimension of the predictor, is less than or equal to 4. When d > 4, the rate turns out to be $n^{-4/(d+4)}$ under the first derivative condition for the regression functions. A numerical study suggests that the proposed estimator has a good finite sample performance.

• Journal of information and communication convergence engineering
• /
• v.5 no.1
• /
• pp.54-58
• /
• 2007

A real-time frame-layer rate control algorithm with a token bucket traffic shaper is proposed for distortion variation minimization. The proposed rate control method uses a non-iterative optimization method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder. Experimental results indicate that the proposed control method provides better visual and PSNR performances than the existing rate control method.

• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.277-287
• /
• 2022

ZEB is a building that increases the energy independence of the building itself, and new and renewable elements that can produce energy are essential, and BIPV is the most notable technology. In ZEB's design, BIPV should be planned early in the design, but BIPV plans are insufficient in the early stages. Therefore, this study derived elements for theoretical consideration of BIM and ZEB and analysis of ZEB independence rate based on BIM, a convergence design technology, and analyzed BIPV energy production and building energy consumption. Finally, by calculating the energy independence rate and reviewing the rating criteria in the project model, a basic research method for calculating the energy independence rate of ZEB at the beginning of the design was presented. Through this, it is expected that design productivity can be improved by supporting the decision of ZEB subjects.

• ETRI Journal
• /
• v.34 no.4
• /
• pp.492-502
• /
• 2012

We consider an overlaid broadcast service, where a spread spectrum (SS)-based broadcast signal is overlaid onto the existing terrestrial Digital Multimedia Broadcasting (T-DMB) band. The system is similar to the augmented data transmission in the ATSC DTV, for which it was investigated mostly in terms of link level performance, such as bit error rate. Our focus in this paper is on the system-level performances. More specifically, utilizing both a large scale path loss and a small scale fading channel model, the primary objective is to explore the tradeoff between the coverage and the achievable rate of the overlaid service and, finally, to determine the achievable rate in the overlaid service for marginal coverage reduction in the existing broadcast service. The analytical and simulation results show that an SS-based add-on service of 10 kbps to 20 kbps can co-exist with the T-DMB service while resulting in only a marginal degradation in T-DMB coverage (for example, less than one percent reduction).

• ETRI Journal
• /
• v.43 no.5
• /
• pp.881-890
• /
• 2021

Photoplethysmography (PPG) is a noninvasive technique that can be used to conveniently measure heart rate (HR) and thus obtain relevant health-related information. However, developing an automated PPG system is difficult, because its waveforms are susceptible to motion artifacts and between-patient variation, making its interpretation difficult. We use deep neural network (DNN) filters to mimic the cognitive ability of a human expert who can distinguish the features of PPG altered by noise from various sources. Systolic (S), onset (O), and first derivative peaks (W) are recognized by three different DNN filters. In addition, the boundaries of uninformative regions caused by artifacts are identified by two different filters. The algorithm reliably derives the HR and presents recognition scores for the S, O, and W peaks and artifacts with only a 0.7-s delay. In the evaluation using data from 11 patients obtained from PhysioNet, the algorithm yields 8643 (86.12%) reliable HR measurements from a total of 10 036 heartbeats, including some with uninformative data resulting from arrhythmias and artifacts.

• ETRI Journal
• /
• v.37 no.2
• /
• pp.241-250
• /
• 2015

In this paper, we present novel high-speed transmission schemes for high-speed ultra-high frequency (UHF) radio-frequency identification communication. For high-speed communication, tags communicate with a reader using a high-speed Miller (HS-Miller) encoding and multiple antennas, and a reader communicates with tags using extended pulse-interval encoding (E-PIE). E-PIE can provide up to a two-fold faster data rate than conventional pulse-interval encoding. Using HS-Miller encoding and orthogonal multiplexing techniques, tags can achieve a two- to three-fold faster data rate than Miller encoding without degrading the demodulation performance at a reader. To verify the proposed transmission scheme, the MATLAB/Simulink model for high-speed backscatter based on an HS-Miller modulated subcarrier has been designed and simulated. The simulation results show that the proposed transmission scheme can achieve more than a 3 dB higher BER performance in comparison to a Miller modulated subcarrier.

• ETRI Journal
• /
• v.26 no.4
• /
• pp.360-366
• /
• 2004

Synchronization Markup Language (SyncML) is a specification of a common data synchronization framework for synchronizing data on networked devices. SyncML is designed for use between mobile devices that are intermittently connected to a network and network services that are continuously available on the network. We have designed and developed a data synchronization system based on the SyncML protocol and evaluated the throughput of the system using the stochastic Petri nets package (SPNP) and analyzed the relationship between the arrival rate and the system resources. Using this model, we evaluate various performance measures in different situations, and we estimate the relationship between the arrival rate and the system resources. From the results, we can estimate the optimal amount of resources due to the arrival rate before deploying the developed system.

• ETRI Journal
• /
• v.34 no.2
• /
• pp.168-174
• /
• 2012

In Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) systems, additional very low-rate data can be transmitted by modulating the amplitude and polarity of the transmitter identification (TxID) signal. Although the additional data transmission scheme offers reliable transmission and has a very large coverage area, it has a limitation on the data rate. In this paper, we propose a novel additional data transmission scheme based on the TxID sequences of the ATSC DTV system and Walsh modulation. The proposed scheme not only increases the data rate significantly, but also offers a virtually identical coverage area compared to a conventional scheme.

• Journal of the Korean Society of Industry Convergence
• /
• v.15 no.3
• /
• pp.71-77
• /
• 2012

This study gives the optimal reaction conditions, reaction mechanisms, reaction rates leaded from the oxidation of phenol by electron beam accelerator and ozone used for recent water treatment. It gives the new possibility of water treatment process to effectively manage industrial sewage containing toxic organic compounds and biological refractory materials. The high decomposition of phenol was observed at the low dose rate, but at this low dose rate, the reaction time was lengthened. So we must find out the optimal dose rate to promote high oxidation of reactants. The reason why the TOC value of aqueous solution wasn't decreased at the low dose was that there were a lot of low molecular organic acids as an intermediates such as formic acid or glyoxalic acid. In order to use both electron beam accelerator and biological treatment for high concentration refractory organic compounds, biological treatment is needed when low molecular organic compounds exist abundantly in sewage. In this experiment, the condition of making a lot of organic acids is from 5 kGy into 20 kGy dose. Decomposition rate of phenol by electron beam accelerator was first order reaction up to 300ppm phenol solution on the basic of TOC value and also showed first order reaction by using both air and ozone as an oxidants.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.151-159
• /
• 2018

This study analyzes the impact of competitions clinics on the total treatment cost and anti-biotics prescription rate. The result of implementing the basic statistics, correlations, and regression analysis by facilitating the evaluation data by Health Insurance Review & Assessment Service in 2015 for acute otitis media in children is shown as follows. First, there is a significant difference for each si-gun-gu for the competition index between total treatment cost and clinics, but there is almost no significant difference for the anti-biotics prescription rate. Second, competition in clinics has statistically important impact on the total examination cost And, third, competition in clinics has no statistically important impact on the anti-biotics prescription rate. There is a need for additional studies on re-examination rate, treatment cost per visit and so forth in order to clarify other factors of competition for medical institutions impacting on the physician behavior in the future studies.