• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.526-533
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• 2014

In this study, we introduce design methodology to develop a guidance for issuing heavy rainfall warning by using both RBFNNs(Radial basis function neural networks) and SVR(Support vector regression) model, and then carry out the comparative studies between two pattern classifiers. Individual classifiers are designed as architecture realized with the aid of optimization and pre-processing algorithm. Because the predictive performance of the existing heavy rainfall forecast system is commonly affected from diverse processing techniques of meteorological data, under-sampling method as the pre-processing method of input data is used, and also data discretization and feature extraction method for SVR and FCM clustering and PSO method for RBFNNs are exploited respectively. The observed data, AWS(Automatic weather wtation), supplied from KMA(korea meteorological administration), is used for training and testing of the proposed classifiers. The proposed classifiers offer the related information to issue a heavy rain warning in advance before 1 to 3 hours by using the selected meteorological data and the cumulated precipitation amount accumulated for 1 to 12 hours from AWS data. For performance evaluation of each classifier, ETS(Equitable Threat Score) method is used as standard verification method for predictive ability. Through the comparative studies of two classifiers, neuro-fuzzy method is effectively used for improved performance and to show stable predictive result of guidance to issue heavy rainfall warning.

• Journal of the Korean Society of School Health
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• v.14 no.2
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• pp.207-213
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• 2001

Objectives: We surveyed the prevalence of smoking among the adolescent population and analysed the correlation of the two exposure biomarkers-concentration of blood cadmium and urinary cotinine-to the smoking status. Methods: Subjects were 193 middle and high school students in Chungnam province. Blood cadmium and urinary cotinine were compared by sex and smoking status. Smoking status were classified by either the concentration of urinary cotinine or subjective answering as a smoker in the questionnaire. Results: Smoking prevalence was 24.6%, 36.2% and 6.7% among all subjects, male and female subjects, respectively. Average smoking amount was 17.5 and 1.5 cigarettes per month among the male subjects and female subjects, respectively. Mean concentration of urinary cotinine among the male subjects was $135.57{\mu}g/{\ell}$, and that of female subjects was $116.59{\mu}g/$. Direct smokers showed higher concentration of urinary cotinine than those of indirect smokers, and subjects with higher urinary concentration showed higher prevalence of smoking, too. Mean concentration of blood cadmium was $0.0572{\mu}g/d{\ell}$ among the male subjects, and $0.0693{\mu}g/d{\ell}$ among the female subjects. Among the male subjects, both exposure biomarkers showed significant correlation to the smoking status, but among the female subjects urinary cotinine did not show significant correlation to the smoking status. Conclusion: Concentrations of these two biomarkers suggested that this population had significantly high evironmental tobacco smoking(ETS) and efficient stop-smoking programs to reduce ETS should be directed to this population.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.525-537
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• 2016

The paper considers a hybrid model to analyze and forecast time series data based on an empirical mode decomposition (EMD) that accommodates complex characteristics of time series such as nonstationarity and nonlinearity. We aggregate IMFs using the concept of cumulative energy to improve the interpretability of intrinsic mode functions (IMFs) from EMD. We forecast aggregated IMFs and residue with a hybrid model that combines the ARIMA model and an exponential smoothing method (ETS). The proposed method is applied to forecast KOSPI time series and is compared to traditional forecast models. Aggregated IMFs and residue provide a convenience to interpret the short, medium and long term dynamics of the KOSPI. It is also observed that the hybrid model with ARIMA and ETS is superior to traditional and other types of hybrid models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.10
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• pp.2348-2356
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• 1997

This paper describes a method of AAL(SSCOP) protocol conformance testing and its result analysis in ATM network. Terminal equipment(TE) that implements protocols for connecting ATM network shall be verified if appropriately implement by conformance testing. The protocol specifications and the testing methodology are recommended or standardized by international standardization organization(ITU-T, ISO, etc.). The ATM AAL (SSCOP) protocol which selected for describing conformance test procedure is standardized in ITU-T Q.2110 and ATM Forum UNI 3.1 which are same in contents. Also Testing standard like ATS for SSCOP is specified in ATM Forum 95-1459R2. Construction of conformance testing environment is necessary to coordinate in relations with standards, then testing must beexecuted at that environment and the results from the test system analyzed. For this, it is necessary to select any test case from standard for testing and to make ETS. The ETS is proted on the test system and conformance testing will execute on that system. Finally the result from the test system is to analyze. This conformance testing procedure is applicable to the same other test cases in SSCOP and protocols in any communcation networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1169-1178
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• 1999

In this paper, the method to improve audio noise when GMS(Global System of Mobile Communication) is built in HPC(Handheld PC)is provided. The biggest problem with quality of audio is improved by connecting GSM module with wire to the widest erea near by HPC Power Ground to reduce impedance difference, and designing amplifier and earpiece, Result of measurement is satisfied with GSM Acoustic Standard. Standard of GSM Audio is declared in GSM 11.10 ETS 300 607-1. Measuring items corresponds to that standard and B&K Type 6712 is used for measurement. The list of measurement presented in this paper is Sending Sensitivity Frequency Response and SLR, Sending Loudness Rating( SLR level), Receiving Sensitivity Loudness Rating(RLR level), Talker Sidetone(STMR), Stability margin, and Echo Loss(ERL)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.305-313
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• 2013

As an FMT (Filtered Multi-Tone) transmission method of Wideband VHF communication system specified by the ETS (European Telecommunications Standards) EN 300 392-2, this paper introduces three existing realization methods, i.e., the direct filtering method using different band SRRC (Square-Root Raised Cosine) filters for each subcarrier, the PPN-DFT method using the IDFT-PPN (Poly-Phase Network) and PPN-DFT at the transmitter and receiver, respectively, and the Extended DFT method. Then, it proposes the extended IDFT-SDFT (Sliding Discrete Fourier Transform) that computes the DFT values only for interested subcarriers every sample time, and shows that it has an advantage of blind symbol timing (using no training symbol) individually for each user signal (independently of other users' signals) in the multi-user environment where the subcarriers are assigned in contiguous or interleaved blocks to each user and each user signal possibly experiences different channels.

• Journal of Digital Contents Society
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• v.11 no.1
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• pp.47-55
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• 2010

Cultural Content Industry, a core industry based on knowledge, is becoming an economic model making new benefits by adding human creativity, imagination, sensitivity and style in to information technology. Cultural Contents Industry representing cultures of each countries is facing major changes towards a new competitive industry of each nation. Cultural content of a country is upbringing new contents power developing into a new industry by flattening the barriers within nations. But cooperations face difficulties in launching the industry because of limited information about the current market and lack of understanding in cultural differences. In order to solve this problem, this paper aims to create global network leading to increase of export and creation of new market with cultural contents and train local specialists. In order to search for the ways to maintain Korean contents in other nations and expand exportation. cooperations invite leading cultural contents groups to South Korea, let the groups experience Korea's contents. Cooperations initiated invite training, dispatch training by Korean companies and international students training. The purpose of this paper is to support education system, ETS-CS(Educational Training System for Contents Specialist) and analyse practices applied in the field to develop a better cultural contents industry.

• Journal of the Korean Data and Information Science Society
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• v.10 no.2
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• pp.485-500
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• 1999

The systematic forecast of interest rates with liberalization was on the rise to important problems in the money market. Liberalization and globalization of the money market produced a seriously change as a compatition among the money market. Profits of an organ of monetary circulation are, also, definitively influenced by a change of interest rates. Hence most of the organ of monetary circulation studied to a scientific and systematic analysis for deterministic factors which have an effect on interest rates and progress development of a forecasting model of interest rates. In this paper, we develope the forecasting system which has highly forecasting performance based on a number of time series models for interest rates and discuss practical use of this system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.89-98
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• 2006

The microbial response after treatment of antibiotics was studied for investigating the resistance pattern under simulated aquaculture environment. A marine microcosm was developed for marine fish farm environment using artificial seawater and sediment. Oxolinic acid, which has been commonly used in aquaculture, was employed for the experiment. Resistance patterns and the changes of microbial community were monitored before. during and after use of oxolinic acid. Vibrionaceae was the dominant bacterial species throughout the experiment, consisting 65-75% of total bacterial number in fish farm environment. However, some gram-positive bacteria, Micrococcos sp. and Bacillus sp. strains in marine farm environment were increased in proportion to their number during the treatment. ETS activity of the bacterial communities in aquaculture environment was reduced to 42-67% during the treatment of oxolinic acid. But recovering trends of bacterial number were also detected immediately after cease of oxolinic acid treatment. Frequent treatment of oxolinic acid under the simulated fish farm environment showed bacterial resistance to increase sharply.

• Environmental and Resource Economics Review
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• v.27 no.4
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• pp.667-694
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• 2018

We analyze the learning-by-doing effects of the allowance pricing system on the Korea's emission trading scheme. The price of allowance (Korean Allowance Unit) is influenced differently by internal market factors and economic conditions variables in the first (January 2015 to June 2016 ) and the second commitment year(January 2016 to June 2017). The prices and transaction volumes of complementary credits (KCU and KOC) as well as economic conditions variables (such as call rate, exchange rate, stock price) are statistically significant only for the second commitment year. Thus, the learning-by-doing effect makes the market participation decision on K-ETS market more efficient in the second commitment year, adopting the previous experience and knowledge in the K-ETS market. The factors estimated significantly in both commitment periods include the institutional binary variable for requiring the submission of the emissions verification reports issued both on February and March.