• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.417-425
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• 2013

Digital communication technology have been focused on the higher data efficiency and the effective coding of information. Also, it is very important to improve security and minimize the interference of the external sources, Chaos communications system is studied to improve security and minimize the interference by effective encoding of information in the nonlinear systems such as DCSK(Differential Chaos Shift Keying) and CDSK(Correlation Delay Shift Keying). In this paper, we evaluate anti-jamming performance of chaos communications system using the DCSK and CDSK system. The simulation results show that the Gauss iterated map has better BER performance than the other maps(tent map, logistic map, Henon map). Also, DCSK and CDSK system can get the better anti-jamming performance by applying different chaotic maps.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.45-52
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• 2021

The article proves the relevance of developing conceptual frameworks for managing the quality assurance of logistics activities in the context of socio-economic interaction of their participants. It is established that the fundamental difference of the logistic approach in management from traditional approaches is the allocation of a single management function of previously separated, disparate material flows, as well as economic, technological, information integration of chain links into a single system capable of effective management of these flows. It is substantiated that the functioning of the enterprise as a logistics system can be represented in the form of a triad of logistics components, namely: supply logistics, production logistics, sales logistics. Management of quality assurance processes of logistics activities in the context of socio-economic interaction of their participants is a functional component of the entire logistics system due to the quality of work and interaction of all participants in the implementation of certain activities. The quality of logistics activities will affect the level of economic potential, rationalization and optimization of all logistics flows. It is proved that the management of quality assurance processes of logistics activities in the context of socio-economic interaction of their participants involves the following main areas: the introduction of a quality system of logistics processes; development and implementation of the general strategy of quality improvement at the enterprise; internal integration; controlling. Management of quality assurance processes of logistics activities in the context of socio-economic interaction of its participants requires compliance with the following requirements: systematic and comprehensive management of all flow processes; coordination of criteria and indicators for assessing the effectiveness of the entire logistics system; dissemination of the use and application of information technology; ensuring partnerships and close interaction of all participants in sales networks.

• Journal of the military operations research society of Korea
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• v.32 no.2
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• pp.165-187
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• 2006

The aim of this study is to suggest the direction of implementing the new defense logistics systems for the network centric warfare in the future. For this purpose, we reviewed SARL(Sense and Response Logistics) which receives great attention from the U.S. Department of Defence as the future logistic concept of network centric warfare, coupled with recent development in information technologies which give technical revolution in the future logistics information system. Also, we analyzed problems underlying logistics information system currently used in the Korean Armed Forces. Finally, we suggested the direction of implementing the new logistics information system for the network centric warfare, expecting to reduce total logistics cost, speed up logistics velocity, and enhance the efficiency of the combat support.

• Journal of Information Processing Systems
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• v.16 no.2
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• pp.377-393
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• 2020

Freight management systems require a new business model for rapid decision making to improve their business processes by dynamically analyzing the previous experience data. Moreover, the amount of data generated by daily business activities to be analyzed for making better decisions is enormous. Online-to-offline or offline-to-online (O2O) is an electronic commerce (e-commerce) model used to combine the online and physical services. Data analysis is usually performed offline. In the present paper, to extend its benefits to online and to efficiently apply the big data analysis to the freight management system, we suggested a system architecture based on O2O services. We analyzed and extracted the useful knowledge from the real-time freight data for the period 2014-2017 aiming at further business development. The proposed system was deemed useful for truck management companies as it allowed dynamically obtaining the big data analysis results based on O2O services, which were used to optimize logistic freight, improve customer services, predict customer expectation, reduce costs and overhead by improving profit margins, and perform load balancing.

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.406-415
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• 2013

The present study examines a set of financial ratios in predicting the up or down movements of stock prices in the context of a securities law, the Sarbanes-Oxley Act of 2002 (SOA), controlling for macroeconomic variables. Using the logistic regression with proxy betas to alleviate the incompatibility problem between the firm-specific financial ratios and macroeconomic indicators, we report evidence that financial ratios are meaningful predictors of stock price changes, which subdue the influence of macroeconomic indicators on stock returns, and more importantly that the SOA truly improves the stock price predictability of financial ratios for the markup sample. The empirical results further suggest that industry and time effects exist and that for the markdown sample the SOA actually deteriorates the predictive power of financial ratios.

• Journal of Forest and Environmental Science
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• v.28 no.3
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• pp.179-184
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• 2012

Dipterocarps (Dipterocarpaceae) is a dominant tree family of tropical rainforest in Southeast Asia. Dipterocarps have been exploited for its timber and disappearing fast in East Kalimantan. In this study, we predicted the distribution of dipterocarpus, one of the main dipterocarps genera, by evaluating its habitat suitability using logistic regression analysis with specimen collection points and environmental factors from GIS data. Current distribution of dipterocarpus was generated by combining the habitat suitability classes with an updated forest cover map. Rainfall, soil type, followed by elevation was the main factors that influence the distribution of dipterocarpus in East Kalimantan. Dipterocarpus can be found in a quarter of the current forest cover, which is highly suitable as habitat of Dipterocarpus.

• Journal of Preventive Medicine and Public Health
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• v.40 no.1
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• pp.64-70
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• 2007

Objectives : This study was conducted to investigate the current status of outsourcing in Korean hospital information systems and the factors influencing its introduction. Methods : The authors surveyed 136 hospitals located in Seoul and its surrounding vicinities from June 7 to June 23, 2006. The facilitators and inhibitors to outsourcing in hospital information systems were derived from literature and expert reviews. Multiple logistic regression analysis was applied to identify the major influencing factors on outsourcing in hospital information systems. Results : Eighty-six (63.2%) of the 136 hospitals surveyed, which were mainly tertiary hospitals, responded to using outsourcing for their hospital information systems. "Hardware and software maintenance and support," "application development," and "management of service and staff" were the major areas of outsourcing. Outsourcing had been employed for $4\sim7$ years by 45.5% of the hospitals and the proportion of the budget used for outsourcing was less than 20%. A need for an extension in outsourcing was agreed on by 76.5% of the hospitals. The multiple logistic regression analysis showed that both consumer satisfaction and security risk have an influence on hospital information system outsourcing. Conclusions : Outsourcing in hospital information systems is expected to increase just as in other industries. One primary facilitator to outsourcing in other industries is consumer satisfaction. We found that this was also a facilitator to outsourcing in hospital information systems. Security risk, which is usually considered an inhibitor to information technology outsourcing, was proven to be an inhibitor here as well. The results of this study may help hospital information systems establish a strategy and management plan for outsourcing.

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.19-30
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• 2004

Due to the inefficient operation of the existing logistic facilities, the complicated distribution structure, and closed utilization of logistic information are causing high logistic costs. The general improvement in the distribution structure and the expansion of the logistic facilities are needed for solving these problems. However, existing unit-scale forecast is not considering the loading and unloading characteristics of the trucks and the improvement of operation efficiency from the mechanization and automation of the loading and unloading works. The queuing theory based on the status quo of the cargo trucks to the cargo terminals is considered in this study. The optimal scale estimation method(OSCM) which the loading and unloading characteristics of the cargo trucks were taken into consideration was suggested. Also, the relationship between the optimal scale of the cargo terminal and the mechanization, automation, and informationization of the present loading and unloading system was investigated. As a result, it showed that the regularity of the truck arrival and service times had less influence on the scale of the cargo terminal, but the improvement of the loading and unloading speeds and the service rate of the trucks did more influence on it.

• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.63-71
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• 2016

This paper is about applying efficient data mining method which improves the score calculation and proper building performance of credit ranking score system. The main idea of this data mining technique is accomplishing such objectives by applying Correlation based Feature Selection which could also be used to verify the properness of existing rank scores quickly. This study selected 2047 manufacturing companies on KOSPI market during the period of 2009 to 2013, which have their own credit rank scores given by NICE information service agency. Regarding the relevant financial variables, total 80 variables were collected from KIS-Value and DART (Data Analysis, Retrieval and Transfer System). If correlation based feature selection could select more important variables, then required information and cost would be reduced significantly. Through analysis, this study show that the proposed correlation based feature selection method improves selection and classification process of credit rank system so that the accuracy and credibility would be increased while the cost for building system would be decreased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.99-104
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• 2000

In this paper, as a digital watermark we propose to use a chaotic sequence instead of the conventional Gaussian sequence. It is relatively easy to generate the chaotic sequence and is very sensitive to the change of initial value. The chaotic sequence adopted in this paper is a modified version of logistic map to give the sequence distribution of Chebyshev map. In the experiments, we applied the Gaussian sequence and chaotic sequence to wavelet coefficients of images to compare the similarity distribution. The results show that, as id the DCT-based watermarking system, the chaotic sequence is robust for various signal processing attacks, Moreover, the similarity variance is smaller than the Gaussian sequence for iterative experiments. It also shows a better performance for compression errors than the Gaussian sequence.