• The Korean Journal of Applied Statistics
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• v.36 no.4
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• pp.295-307
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• 2023

The heterogeneous autoregressive (HAR) model is a simple linear model that is commonly used to explain long memory in the realized volatility. However, as realized volatility has more complicated features such as conditional heteroscedasticity, leverage effect, and volatility clustering, it is necessary to extend the simple HAR model. Therefore, to better incorporate the stylized facts, we propose a threshold HAR model with GARCH errors, namely the THAR-GARCH model. That is, the THAR-GARCH model is a nonlinear model whose coefficients vary according to a threshold value, and the conditional heteroscedasticity is explained through the GARCH errors. Model parameters are estimated using an iterative weighted least squares estimation method. Our simulation study supports the consistency of the iterative estimation method. In addition, we show that the proposed THAR-GARCH model has better forecasting power by applying to the realized volatility of major 21 stock indices around the world.

• Journal of the Korean Dietetic Association
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• v.9 no.1
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• pp.1-12
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• 2003

The purpose of this study was to investigate the knowledge and perception for Kimchi in middle school students. A questionnaire was used as the instrument of investigation. The subjects were 375 male students and 278 female students in Masan and Changwon City. The main results of this study are as follows. Ninety-three point three percent of the subjects were nuclear family type and 61.7% of respondent's mother had job. The average knowledge score for Kimchi of the subjects was 5.27 out of possible 10 points and the average value score on Kimchi was 41.25 out of 50 points. Eighty-six point one percent of students think they should eat Kimchi because Kimchi is good for the health(38.6%) and Kimchi is our traditional food(31.4%), and it was significantly difference between gender(p<0.01), male students more realized 'Kimchi is good for the health(41.6%)', whereas female students more realized 'Kimchi is our traditional food(38.9%)'. The subjects perceived that the additive material making for Kimchi were powdered red pepper(80.2%), garlic(62.5%), salt(62.0%), salted, fermented shrimp(50.2%). ginger(49.5%), green onion(39.8%), salted, fermented anchovy(34.9%), sesame(25.0%), carrot(22.4%). More than 70% of the subjects estimated for Kimchi 'Kimchi is our traditional food(84.1%)', 'Kimchi must be developed the international food'(73.7%), 'Kimchi must be in succession(75.8%)', 'Kimchi is very nutritious food(70.3%)'. However, they thought Kimchi have to be improved more hygienically(38.8%) and less stimulative taste(25.7%). The knowledge for Kimchi showed a positive correlation with the value on Kimchi and the preferences for Kimchi, and the value on Kimchi was a positively related to the preferences for Kimchi(p<0.01). Therefore it is need to the development of program for the knowledge for Kimchi and the value on Kimchi in order to improvement the preferences for Kimchi.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.1
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• pp.32-37
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• 2023

This study has evaluated the genomic estimated breeding value (GEBV) of the commercial Hanwoo population using the genomic best linear unbiased prediction (GBLUP) method and genomic information. Furthermore, it analyzed the accuracy and realized accuracy of the GEBV. 1,740 heads of the Hanwoo population which were analyzed using a single nucleotide polymorphism (SNP) Chip has selected as the test population. For carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS), the mean GEBVs estimated using the GBLUP method were 3.819, 0.740, -0.248, and 0.041, respectively and the accuracy of each trait was 0.743, 0.728, 0.737, and 0.765, respectively. The accuracy of the breeding value was affected by heritability. The accuracy was estimated to be low in EMA with low heritability and high in MS with high heritability. Realized accuracy values of 0.522, 0.404, 0.444, and 0.539 for CWT, EMA, BFT, and MS, respectively, showing the same pattern as the accuracy value. The results of this study suggest that the breeding value of each individual can be estimated with higher accuracy by estimating the GEBV using the genomic information of 18,499 reference populations. If this method is used and applied to individual selection in a commercial Hanwoo population, more precise and economical individual selection is possible. In addition, continuous verification of the GBLUP model and establishment of a reference population suitable for commercial Hanwoo populations in Korea will enable a more accurate evaluation of individuals.

• The Korean Journal of Health Service Management
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• v.10 no.3
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• pp.1-12
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• 2016

Objectives : This study examined relations between investment efficiency and management performance as indexes related to productivity of Korean regional public hospitals. Methods : The analysis data are financial information of Korean regional public hospitals from 2011 to 2014. For the indicators, value added to total assets, value added to productive activity tangible fixed assets, and value added to personnel expenses, operating margin to revenues, net profit to total earnings, and ratio of value added. Results : Significant relevance was not shown among indicators of investment efficiency. However, Significant relevance was shown between value added to personnel expense and productivity per value added. Conclusions : It confirmed that outside support funds like subsidy did not have effect on improving the management performance. Also, it could be known that availability about input of capital and labor was not realized organically.

• Journal of the Korean Society of Systems Engineering
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• v.4 no.2
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• pp.35-43
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• 2008

Application of system engineering should be realized on necessary condition being to propel National Defense R&D Program. But, these necessity is yet not realized easily to many project managers of Defense Acquisition Program Administration(DAPA). As one person of DAPA project manager, system engineering hard to approaches easily by the word itself. There are a lot of difficult sections where should apply how. This paper established DAPA Project Manager and Acquisition Point of Contact of demand Military by main customer (reader), and wished to make understood more easily and approach system engineering application to these. Also, this paper studied project management example that scientific project management techniques of Earned Value Management(EVM) and Cost As an Independent Variable(CAIV) etc. is taken abuzz in DAPA inside by Project management technique that become reform, arc Integrated in system engineering.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.121-125
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• 2010

In this study, we have constructed this algorithm that theoretical method for prediction performance of the internal ballastic analysis. And we have confirmed reliability, compared the value calculated by realized program with the value computed by modeling program. A basic concept of algorithm expresses combustion phenomenon to move each factor(node) according to the time increment like as Finite element method. And we have confirmed this realized program has sufficient possibility to utilize in the internal ballastic analysis.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.66-80
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• 2022

Even before the Covid-19 outbreak, the second-hand fashion market has been growing as the fashion industry strives towards sustainability. It has also accelerated due to the economic contraction caused by the pandemic. In previous studies, the second-hand market has been steadily studied; however, the research is insufficient compared to the diversified market. Therefore, this study investigates changes in consumers' perception of the second-hand fashion market affected by Covid-19. This study collected text data with the keyword 'second-hand fashion' from various blogs. We analyzed 24,000 posts before and after the Covid-19 outbreak by applying the LDA algorithm for topic modeling and content analysis. Seven and nine different topics for the period before and after the pandemic respectively were derived. The results revealed that during the pandemic the consumers realized the practical value of sustainability in their daily lives than they did before the pandemic. Furthermore, they tried to minimize transaction anxiety by using diverse platforms with advanced technology. They also realized economic value by buying and selling sneakers in the popular sneakers resale market. The results could help understand the rapidly growing second-hand fashion market during Covid-19.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.620-623
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• 2000

A very simple control approach using neural network for the robust position control of a Permanent Magnet Synchronous Motor(PMSM) is presented The linear quadratic controller plus feedforward neural network is employed to obtain the robust PMSM system approximately linearized using field-orientation method for an AC servo. The neural network is trained in on-line phases and this neural network is composed by a fedforward recall and error back-propagation training. Since the total number of nodes are only eight this system can be easily realized by the general microprocessor. During the normal operation the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. And the state space analysis is performed to obtain the state feedback gains systematically. IN addition the robustness is also obtained without affecting overall system response. This method is realized by a floating-point Digital Singal Processor DS1102 Board (TMS320C31) The basic DSP software is used to write C program which is compiled by using ANSI-C style function prototypes.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.104.2-104
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• 2001

In the intelligent integrated systems, the delay time must be reduced using highly parallel processors, as well as high throughput performance. In this paper, we propose a new concept for building 3D highly parallel processors using multi-layer printed wiring boards with built-in soldering heater (BISH-PWB). The proposed BISH is realized with the long and narrow cupper wiring pattern on the internal layer in the terminal pattern area. Based on the linearity of the cupper resistance vs. temperature, we can measure the BISH, temperature and its calorific value from the heater voltage and current measurements. If we provide the BISH temperature control systems for each BISH, selective multi-point soldering can be realized with same ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.179.2-179
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• 2001

This paper is about to consist of neutralization public decision system which is level controled the amount of inflow and outflow water to make use of PLC in automatic system and according to numerical value of PH, which is projected into a water tank counteragent automatically. But neverthless, appearance of extended PLC, there is a limit to realize from automatic system to intellectual system which is more efficient and active. There are two problems in PLC. First, there is not generalized that a module of PLC (which is installed in PLC) is realized control algorithm form. Second, there is a difficulty of expression that provided PLC control language is realized. There fore I take fuzzy inference control technique of various intellectual algorithm and 1 make a control rule and ...