• KIEAE Journal
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• v.17 no.2
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• pp.13-20
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• 2017

Meteorological data is one of the important factors in the calculation of building energy demand. The purposes of this study are to review the limitations of the typical meteorological data of ECO2 program and to create the new typical meteorological data and then analyze the building energy demands for additional regions which are not included in the existing 13 region in the ECO2 program. The extended typical meteorological data to a total of 33 regions were based on IWEC(International Weather for Energy Calculations) data files and were created in the form applicable to the building energy efficiency rating certification system. As a result of comparing the heating energy demands of a representative region with the surrounding regions in each of five regions in Korea, the variance of Cv(RMSE) ranged from 36% to 344% and MBE ranged from -32% to 190% for the whole regions. This suggests that the difference of heating energy demand may vary greatly depending on the region where the meteorological data is used and the meteorological data of more detailed regions is needed for reliable calculation of building energy demand.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.933-950
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• 2018

In Japan, Wagyu cattle include four Japanese breeds; Black, Brown, Shorthorn, and Polled. Today, the renowned brand name Wagyu includes not only cattle produced in Japan, but also cattle produced in countries such as Australia and the United States. In recent years, the intramuscular fat percentage in beef (longissimus muscle) from Japanese Black cattle has increased to be greater than 30%. The Japanese Black breed is genetically predisposed to producing carcass lipids containing higher concentrations of monounsaturated fatty acids than other breeds. However, there are numerous problems with the management of this breed including high production costs, disposal of untreated excrement, the requirement for imported feed, and food security risks resulting from various viral diseases introduced by imported feed. The feeding system needs to shift to one that is more efficient, and improves management for farmers, food security for consumers, and the health environment for residents of Japan. Currently, we are developing a metabolic programming and an information and communications technology (ICT, or Interne of Things) management system for Wagyu beef production as future systems. If successful, we will produce safe, high-quality Wagyu beef using domestic pasture resources while solving the problems of how to utilize increasing areas of abandoned agricultural land and to make use of the plant-based feed resources in Japan's mountainous areas.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.74-85
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• 2020

This paper presents an algorithm that evaluated the overload influence by bus upon the distribution system by calculating the daily load curve of PEVs charging by bus based on the daily charging patterns of PEVs according to PEVs penetration scenarios. The proposed algorithm calculates the number of PEVs to estimate the number of households by bus; the probability density function of the charging start time of PEVs, considering driving characteristics of PEVs and the daily load curve of PEVs charging by bus considering battery characteristics according to PEVs penetration scenarios. To verify the evaluation of the overload influence by bus on the distribution system in terms of the proposed algorithm, the cases were reviewed on the target bus(apartment and detached houses) among the feeders of the distribution systems at Dongtan new-town in Korea.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.19-24
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• 2020

Artificial intelligence technology, which is the core of the 4th industrial revolution, is making intelligent judgments through deep learning techniques and machine learning that it is impossible to predict if it is applied to stock prediction beyond human capabilities. In US fund management companies, artificial intelligence is replacing the role of stock market analyst, and research in this field is actively underway. In this study, we use BLSTM to reduce errors that occur in unidirectional prediction of the existing LSTM method, reduce errors in predictions by predicting in both directions, and macroscopic indicators that affect stock prices, namely, economic growth rate, economic indicators, interest rate, analyze the trade balance, exchange rate, and volume of currency. To help stock investment by accurately predicting the target price of stocks by analyzing the PBR, BPS, and ROE of individual stocks after analyzing macro-indicators, and by analyzing the purchase and sale quantities of foreigners, institutions, pension funds, etc., which have the most influence on stock prices.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.410-416
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• 2013

In this paper, we propose a chaotic correlation delay shift keying(CDSK) using digital retrodirective array antenna (RDA) for improving security and receive performance. Chaotic signals provide improved security due to non-periodic and non-predictable performance of chaotic signals. However, the receive performance of these chaotic signals is degraded due to self-interference and interference signals. Therefore, this paper, we analyze the receive BER performance of chaos communication system which has digital RDA based on CDSK modulation schemes for improving security without receive performance degradation. Simulation results show that the proposed system can get the same receiving performance compared to BPSK modulation schemes when array elements of RDA are 5.

• Journal of Korea Port Economic Association
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• v.33 no.1
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• pp.61-74
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• 2017

The aim of this study is to analyze informatization competencies of the international ship supply companies at Busan port. This study comprehensively suggests certain issues attributed to the successful implementation of total information management system for ship supply. To achieve this objective, evaluation was undertaken based on the model of the National Competency Standards (NCS). This model consisted of three evaluation areas, including 20 items. Analysis of information competencies of ship supply companies was undertaken using the Importance-Performance Analysis (IPA) method. Survey data was collected from ship supply companies located in the ship supply center at Busan port. Results found that there were significant differences between importance and performance. In addition, overall informatization competency was very low. Thus, in order to ensure successful implementation of total information management system, re-education programs for ICT usage and dedicated support organization are necessary.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1933-1941
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• 2016

This paper compares the performance of wireless communication technologies to replace the wired networks by wireless networks on avionics intra-communication. Due to the drawbacks of wired network, such as complexity, weight, maintenance cost and scalability, it leads to the high data rate and network traffic demands of avionics systems. Therefore, in WAIC(Wireless Avionics Intra-Communications) system suggested by ITU(International Telecommunication Union), based on environment of avionics system and requirements of a wired network, wireless network structures are defined to solve the problems of wired networks. In this paper, we consider features, advantages and disadvantages of wireless communication technologies which can be used for wireless avionics network, and we propose suitable wireless communication technology candidates for wireless avionics networks in WAIC environments.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.175-180
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• 2017

In accordance with the development of IT industry worldwide, software industry has also grown tremendously, and it is exerting influence on the general society starting from daily life to financial organizations and public institutions. However, various security threats that can inflict serious threat to provided services in proportion to the growing software industry, have also greatly increased. In this thesis, we suggest a smart fuzzing system combined with black box and white box testing that can effectively detectxdistinguish software vulnerability which take up a large portion of the security incidents in application programs.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.129-136
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• 2020

The purpose of this study is to identify the influence of external-social and cultural factors on the perception of corruption in the public society through the Structural Equation Model(SEM) and to seek ways to reduce corruption in the public society. Currently the level of corruption in public sectors that people think is still large, and it is necessary to continuously reduce corruption in public sectors in order to improve national competitiveness. Since one society is a part of a country in system theory and social network theory, public society needs quantitative research in order to find the causes of corruption and solve them. The model was built and the variables were defined in SEM based on 600 questionnaires. As a result of analysis, corruption in public offices has decreased since the implementation of the solicitation and graft law, and socio-cultural factors have had a direct impact on corruption in public offices. The further research area is to seek detailed ways for transforming the education and awareness of civil society across the country in addition to the efforts of the public officials themselves in order to reduce corruption in public offices.

• Biomedical Engineering Letters
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• v.8 no.4
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• pp.383-392
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• 2018

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.