• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.285-294
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• 2018

In this study, we implemented the data quality monitoring algorithm which is the previous step for real-time Global Navigation Satellite System (GNSS) correction generation and compared Global Positioning System (GPS) and BeiDou System (BDS). Signal Quality Monitoring (SQM), Data QM, and Measurement QM (MQM) that are well known in Ground Based Augmentation System (GBAS) were used for quality monitoring. SQM and Carrier Acceleration Ramp Step Test (CARST) of MQM result were divided by satellite elevation angle and analyzed. The data which are judged as abnormal are removed and presented as Root Mean Square (RMS), standard deviation, average, maximum, and minimum value.

• Journal of Distribution Science
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• v.16 no.5
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• pp.91-101
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• 2018

Purpose - This study compares the management efficiency of retailers in China, Korea and other global countries. China's retail industry is experiencing a recession. In order to strengthen the competitiveness of retailers, it is necessary to manage the efficiency. Therefore, we analyzed the management efficiency of Chinese retailers as well as Korea and global retailers who are competing with Chinese retailers. Research design, data, and methodology - The DEA(Data Envelopment Analysis) carried out for evaluating the relative efficiency of multiple DMUs (decision making units) with homogeneity. Data were collected from the American Retail Trade Association (2017). In those distributors' data, 5 of China and 5 of Korea and 10 of other global countries' analyzed. CCR and BCC analysis were performed to determine the cause of the inefficiency of DMUs by measuring the technical efficiency, pure technology efficiency and scale efficiency. Result - Among the 20 retail distributors, Costco, Kroger (Global), Eland World, BGF(Korea) are operating efficiently. Chinese retailers are operating inefficiently. Retailers' CRS status means the growth rate of input is equal to the growth rate of output. In the case of DRS status, the ratio of output to input variable is much smaller. In order to improve inefficiency, reducing input variables can be a solution. For the firms in IRS status, the rate of increase in output is relative greater than the input. That means efficiency is good condition. The analysis result shows that most retailers are showing DRS status especially Chinese retailers. Scale efficiency is a major cause of inefficiency rather than pure technology efficiency. It is recommended for ineffective retailers to reduce inputs to become efficient retailers. Otherwise, retrain existing employees or introducing advanced technologies to increase the output. Conclusions - Most of Chinese retailers are operating inefficiently which caused by the excessive investment in the inputs. On the other hand, Other global retailers are analyzed to be efficient by DEA. In this study, benchmarking targets of some retailers' suggested to improve the management efficiency especially in inputs.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.217-225
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• 2021

In this paper, we designed and implemented the integrated system to prevent adverse drug reactions of polypharmacy components in medicine by supporting component-component information and disease-component information, through data queuing algorithm and vast amounts of pharmaceutical big data. In addition, by providing information for drugs, drug components, prohibited drugs, as well as suppliers and distributors, it could help ease anxiety about taking drugs not only for health-care professionals but also for general users. The representative information provided were side effects between two drugs, main components and effectiveness of particular drugs, drugs manufactured by the same pharmaceutical company, and drug component information for patients with chronic diseases. The future work is to update the database by collecting information on rare & new diseases and new drugs.

• Bulletin of the Korean Mathematical Society
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• v.55 no.2
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• pp.591-598
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• 2018

This paper is concerned with global existence of weak solutions to the relativistic Vlasov-Klein-Gordon system. The energy of this system is conserved, but the interaction term ${\int}_{{\mathbb{R}}^n}\;{\rho}{\varphi}dx$ in it need not be positive. So far existence of global weak solutions has been established only for small initial data [9, 14]. In two dimensions, this paper shows that the interaction term can be estimated by the kinetic energy to the power of ${\frac{4q-4}{3q-2}}$ for 1 < q < 2. As a consequence, global existence of weak solutions for general initial data is obtained.

• 한국IT서비스학회:학술대회논문집
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• 2003.05a
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• pp.222-229
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• 2003

In the process of global transportation, many value chains which have different business process, system and technology level respectively are connected to each other. To obtain end-to-end visibility of transportation, these kind of discrepancy has to be solved appropriately. In this paper, the realization of global visibility is discussed in three point of view such as 'Data Sourcing', 'System integration' and 'System Operation'. First, the data sources of global visibility are described especially from the point of enterprise applications view, and then system integration is presented using various current e-commerce technologies for example XML, EDI and so on. Finally, flexible operation of visibility function is suggested which satisfies different goals of each value chain.

• Phonetics and Speech Sciences
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• v.1 no.1
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• pp.69-73
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• 2009

This paper proposes an efficient global covariance-based principal component analysis (GCPCA) for speaker identification. Principal component analysis (PCA) is a feature extraction method which reduces the dimension of the feature vectors and the correlation among the feature vectors by projecting the original feature space into a small subspace through a transformation. However, it requires a larger amount of training data when performing PCA to find the eigenvalue and eigenvector matrix using the full covariance matrix by each speaker. The proposed method first calculates the global covariance matrix using training data of all speakers. It then finds the eigenvalue matrix and the corresponding eigenvector matrix from the global covariance matrix. Compared to conventional PCA and Gaussian mixture model (GMM) methods, the proposed method shows better performance while requiring less storage space and complexity in speaker identification.

• Ocean and Polar Research
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• v.30 no.4
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• pp.373-378
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• 2008

Long-term tide-gauge data from around the Korean Peninsula were reanalyzed. Both the coastal water and the open sea surrounding the Korean Peninsula appeared to have been influenced by global warming. The long-term change in relative sea levels obtained from tidal stations showed a general rising trend, especially near Jeju Island. It is proposed that global warming may have caused shifting of the path of the Kuroshio branch (Tsushima Warm Current) toward Jeju Island, causing a persistent increase in the water levels along the coast of the island over the last few decades.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2000.09a
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• pp.176-181
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• 2000

This paper briefly outline the approach we are now setting for improving the existing global ocean tidal charts in next few years. There has been notable progress in predicting global ocean tide in mid 90s to improve correction procedures for tidal signals in altimetry with more accurate tidal models (http://podaac.jpl.nasa.gov/) than existing ones. (omitted)

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.123-128
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• 2012

Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design. The purpose of our work is to predict the surface temperature on inclined surfaces based on ISO-TRY typical weather data. To reach this goal, three studies were performed. They consisted of quantifying the accuracy of various well-known three models. The first type of models calculated diffuse horizontal irradiations from global ones and the second type models computed global irradiations on inclined planes from diffuse and global components on a horizontal surface. The third type of model calculated long-wave radiation and surface temperature from ISO-TRY typical weather data. The proposed model can provide an alternative to building designers in estimating the surface temperature and solar irradiation on inclined surfaces where only the typical meteorological data are available.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.282-285
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• 2007

Satellite observed brightness temperature simulation using a radiative transfer model (here after, RTM) is useful for various fields, for example sensor design and channel selection by using theoretically calculated radiance data, development of satellite data processing algorithm and algorithm parameter determination before launch. This study is focused on elaborating the simulation procedure, and analyzing of difference between observed and modelled clear sky brightness temperatures. For the CMDPS (COMS Meteorological Data Processing System) development, the simulated clear sky brightness temperatures are used to determine whether the corresponding pixels are cloud-contaminated in cloud mask algorithm as a reference data. Also it provides important information for calibrating satellite observed radiances. Meanwhile, simulated brightness temperatures of COMS channels plan to be used for assessing the CMDPS performance test. For these applications, the RTM requires fast calculation and high accuracy. The simulated clear sky brightness temperatures are compared with those of MTSAT-1R observation to assess the model performance and the quality of the observation. The results show that there is good agreement in the ocean mostly, while in the land disagreement is partially found due to surface characteristics such as land surface temperature, surface vegetation, terrain effect, and so on.