• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.2 s.308
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• pp.73-81
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• 2006

This paper proposes the improved orthogonal projection method as a new technique advancing the performance of the acoustic echo canceller. Comparing with the widely used NLMS adaptive algorithm which is simple and stable, it shows that this method has the improvement of the convergence speed for signals with the large auto-correlation, and has small computational quantities. In order to testify performances of the orthogonal projection method whom this paper proposes, we have coded a simulation program md executed computer simulations. We observed convergence curves by using two adaptive algorithm for noises and speeches. From simulation results for two input signals, the proposed method shows the high ERLE and the fast convergence and the stable operation in case of using speeches as well as noises.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.712-716
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• 2008

In this paper, we introduce a way to generate and control the serial music using stochastical tools. A serialism, which is one of composition techniques in the 20th century modern music, is composed using uniformly distributed notes or durations. To conserve this property, we design the optimization process to generate the random numbers which can be used to compose the serial music. The optimization are designed using chi-square test and auto-correlation test. User can also apply the additional constraint to the objective function for controlling the serial music. Using the our method, we can compose and control the traditional serial music automatically.

• Computational Structural Engineering
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• v.5 no.3
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• pp.127-137
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• 1992

A method for nonstationary response analysis of an offshore guyed tower subjected to earthquake loading is presented. The nonstationarity of the earthquake excitation is modeled by imposing a time varying envelope function onto a stationary random model. By taking the envelope function and the auto-correlation function of ground acceleration in terms of complex exponential functions of time, an analytical procedure is developed for computing time varying variances of the tower response. Example analysis indicates that the maximum responses estimated by considering nonstationary effect properly are significantly less than those obtained by the conventional frequency domain analysis method based upon the stationary assumption.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.127-134
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• 2008

This study was carried out in 14,443 subjects(8,706 men, 5,737 women, mean age $41.8{\pm}9.16$) who visited the health promotion center of one university hospital. Serum $T_3$, $T_4$ and TSH concentrations were measured with CIA using commercial kits on ADVIA Centaur Assay and Serum total cholesterol, triglyceride, and HDL-cholesterol were measured by auto-analyzer Hitach 7600 in enzyme method. 1. The prevalence of subclinical hypothyroidism was 12.6/1,000 population(men 6.0/1,000, women 22.7/1,000) and as high as about 4 times in women than in men. 2. In subclinical hypothyroidism, the values of total cholesterol and LDL-cholesterol were significantly high by 5.5 mg/dL, 4.6 mg/dL compared with normal group(p<0.05). 3. In all the tested hypercholesterolemia and hyperLDL-cholesterolemia, were correlated with TSH. There is higher correlation in women group than men group. These results indicate that the subclinical hypothyroidism and dyslipemia significantly correlated. Especially, it is very important to find that the hypercholesterolemia and hyperLDL-cholesterolemia are the high risk factors of atherosclerosis. Therefore, it is essential for the group of subclinical hypothyroidism to take the cholesterol, LDL-cholesterol and serum lipid test as well as thyroid function test.

• Advances in environmental research
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• v.4 no.2
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• pp.83-104
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• 2015

Air Quality Index (AQI) is a pointer to broadcast short term air quality. This paper presents one day ahead AQI forecasting on seasonal basis for three major cities in Maharashtra State, India by using Artificial Neural Networks (ANN) and Genetic Programming (GP). The meteorological observations & previous AQI from 2005-2008 are used to predict next day's AQI. It was observed that GP captures the phenomenon better than ANN and could also follow the peak values better than ANN. The overall performance of GP seems better as compared to ANN. Stochastic nature of the input parameters and the possibility of auto-correlation might have introduced time lag and subsequent errors in predictions. Spectral Analysis (SA) was used for characterization of the error introduced. Correlational dependency (serial dependency) was calculated for all 24 models prepared on seasonal basis. Particular lags (k) in all the models were removed by differencing the series, that is converting each i'th element of the series into its difference from the (i-k)"th element. New time series is generated for all seasonal models in synchronization with the original time line & evaluated using ANN and GP. The statistical analysis and comparison of GP and ANN models has been done. We have proposed a promising approach of use of GP coupled with SA for real time prediction of seasonal multicity AQI.

• Journal of Satellite, Information and Communications
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• v.11 no.1
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• pp.32-36
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• 2016

In this paper, a transceiver of VLC (Visible Light Communication) using LED white lighting has been implemented. We analyzed differences between conventional wireless communication and VLC with high-speed data transmission in a variety of environments, and confirmed symbols which passed through a channel using QAM. In order to get a high data rate, we found some variables that should be considered essentially though experiments. In addition, we set a bandwidth and found an optimal gain according to the distance between transmitter and receiver. We analyzed proposed system model through Labview and finally showed a system performance and to efficient data transmission and detection for VLC, we apply the orthogonal sequences to VLC system.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.60-67
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• 2007

The spectrum sensing is important for decision of using frequency band. It checks the frequency band for cognitive radio system. In this paper, we apply autocorrelation function to the energy detection method. We use the autocorrelation function to improve the performance of spectrum sensing method based on the energy detection method. This method is different from cyclostationary process method where parameters such as the mean or the autocorrelation function are time-varying periodically. And we propose improved method that is robust in poor radio environment. If the proposed method applies for sensing in the cognitive radio system, it will have the structural simplicity and the fast computation of spectrum sensing.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.691-700
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• 2017

This paper describes the design and implementation of automatic braille converter based on image processing for a person who is visually impaired. The conversion algorithm based on the image processing converts the input image obtained by the web-cam to binary image, and then calculates the cross-correlation with the stored character pattern image by labeling the character area and converts the character pattern image into the corresponding braille. The computer simulations showed that the proposed algorithm showed 95% and 91% conversion success rates for numerals and alphabets printed on A5 paper. The prototype test implemented by the servo motor using Arduino confirmed 89%, conversion performance. Therefore, we confirmed the feasibility of the automatic braille transducer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.906-912
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• 2009

Offline-based study is proceeding effectively for directly teaching and communication between a learner and a professor. In general virtual education system have been solve this problem using provides search of particular learning domain and auto feedback of relative learning domain after examination. But the learner needs personally select the right document among search result set and interconnected precedence study domain. Therefore, the unskilled learner is difficult of learning progress over against offline-based study. This paper suggests a index mechanism of varied views for helps to learner understand the flow and direction of learning and correlation between units.

• The Korean Journal of Community Living Science
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• v.23 no.3
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• pp.245-254
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• 2012

This study was performed to determine the component analysis and measurements of antioxidant activities from natural seasoning containing Lentinus edodes powder (NSLP) in order to detect the biological activities and develop novel functional resources. It was extracted with 70% ethanol and then further fractionated to hexane, chloroform, ethyl acetate, butanol and water. Methods used in this experiment were measured to examine total polyphenol contents and total flavonoid contents, reducing power and Superoxide dismutase-like activity. Composition analysis were highly composed of carbohydrate as 44.1%. The minerals of different organics were highly composed of sodium as 5,073 mg/100g. There were seventeen total amino acids in NSLP. The glutamic acid content was high up to 16.9 mg/g and aspartic acid, lysine, leucine, alanine were followed. Predominant fatty acid was linoleic acid (62.7%) in NSLP. Contents of total polyphenols in butanol fraction from NSLP were 16.38 mg/100mL. While overall butanol fraction have higher reducing power than ethanol extract, after the addition of 400 ${\mu}g/mL$ butanol fraction, auto oxidation of pyrogallol decreased to 83.62% as a result of superoxide dismutase-like activity. A positive correlation was observed between total polyphenol, flavonoid and antioxidant activities.