• 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.

• Korea Trade Review
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• v.47 no.1
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• pp.79-97
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• 2022

This study aims to analyze the effects of the characteristics of startups and the role of accelerators on internationalization performance. To achieve this purpose, we collected data from the management of 180 startups promoting overseas expansion. As a result of empirical analysis, it was confirmed that among the characteristics of startups, innovativeness, learning orientation, and global orientation had a significant effect on internationalization performance. In addition, it was confirmed that the role of the accelerator has a positive effect on the internationalization performance.

• Journal of Korean Society for Quality Management
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• v.45 no.1
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• pp.65-92
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• 2017

Purpose: The performance of global major airports is evaluated and several research questions are examined relative to the measures characterizing airport performance. Methods: The two-stage internal structure of airport performance is considered by decomposing it into physical operations and revenue generation. In the physical operations stage, operating costs, number of runways, terminal area and number of employees are used as inputs, while passenger throughput, cargo throughput and aircraft movements are taken as outputs. Subsequently, in the revenue generation stage, the outputs from the preceding stage are taken as inputs, while revenue is used as output. Results: Based upon this two-stage modeling of airport performance, a multiplicative two-stage network data envelopment analysis model is employed to calculate the overall and stage efficiencies of 59 airports using the recent data in the 2014 Airport Benchmarking Report published by the Air Transport Research Society. Several internal and external factors are also considered such as airport size, airport geographical location, proportion of international passengers, ownership (listed or not) and management style, and statistical analysis is performed to examine their impacts on airport performance. Conclusion: It is shown that the airports exhibit statistically significant difference across regions, and also some statistically significant factors affecting airport performance are identified.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.3
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• pp.215-220
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• 2024

In urban areas, signals can be blocked and reflected by buildings, reducing the reliability of global navigation satellite systems (GNSS). To address this, the zonotope shadow matching (ZSM) algorithm has been proposed to estimate the set-valued receiver position by calculating the GNSS shadow based on the zonotope. However, the existing study only analyzed the performance of ZSM in dense urban areas where GNSS shadows occur frequently, and the performance analysis in various urban environments was insufficient. Therefore, in this paper, we analyzed the performance of the ZSM algorithm in four urban environments with different characteristics. The results showed that the receiver position estimation performance of ZSM was relatively poor in environments where buildings were not densely populated, and the performance of ZSM was shown to be effective in urban environments with narrow roads and tall buildings.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.1
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• pp.15-24
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• 2018

This study analyzed positioning accuracy of the multi-differential global navigation satellite system (DGNSS) algorithm that integrated GPS, GLONASS, and BDS. Prior to the analysis, four sites of which satellite observation environment was different were selected, and satellite observation environments for each site were analyzed. The analysis results of the algorithm performance at each of the survey points showed that high positioning performance was obtained by using DGPS only without integration of satellite navigation systems in the open sky environment but the positioning performance of multi-DGNSS became higher as the satellite observation environments degraded. The comparison results of improved positioning performance of the multi-DGNSS at the poor reception environment compared to differential global positioning system (DGPS) positioning results showed that horizontal accuracy was improved by 78% and vertical accuracy was improved by 65% approximately.

• Journal of Korea Technology Innovation Society
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• v.16 no.3
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• pp.605-629
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• 2013

The aim of this study is analyzing the factors and performance related to the entry control mode when a SME advances into the global market. For this, the strategic factor of the SME was divided into the enterprise capabilities consisting of technology commercial capability, internal capability, and global capability of enterprise and information capabilities that are the capabilities on the global market and on the advanced technology. In the empirical study, a total of 27 variables that include the control variables and the financial and non-financial variables as a performance variable was used. The hypothesis was also established for analyzing the effect of the entry strategies on the entry control mode and the effect of the mode on performance. Logistic regression was conducted for verifying the hypothesis, and Multiple regression analysis and T-test were carried out on the additional analysis related to the performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.1
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• pp.57-73
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• 2015

While many previous studies investigated the effect of operations performance on financial performance, most studies considered only a few performance indicators and ignored the characteristics of industries. Therefore, this study intends to analyze the effect of operations performance on financial performance, by selecting a rather comprehensive operations performance indicators from firms' financial data. In doing so, we used operating efficiency and supply chain performance indicators for operations performance and a firm's profitability and future value indicators for financial performance. For the analysis, we collected 544 firms' operations and financial performance data belonging to eight key industries from the 'Forbes Global 2000'. We first analysed the differences in operations and financial performance among high, medium and low supply chain performance groups based on the quantitative criteria of Gartner's 'Supply Chain Top 25' ranking procedure. Then we analysed the effect of operations performance indicators on financial performance for both entire industry and individual industries, using multiple regression. Based on the results, we provided practical insights into key operations performance indicators to focus on and manage in order to improve financial performance.

• International Area Studies Review
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• v.14 no.1
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• pp.141-160
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• 2010

The paper examines the determinants factor and business performance of global supply chain management. Partnership and process innovation were used as proxy for the characteristics of determinants factor of global supply chain management. Agility of business performance was used as proxy for the business performance of global supply chain management. Based on the analysis of sixty eight global supply chain management cases in Oil and Chemical Industry, the following results were found. Firstly, it was found that the process partnership of determinants factor affects agility of improved business performance. Secondly, process innovation of determinants factor was not improved more agility of improved business performance. However, there were several limitations such as characteristics of process innovation and partnership, etc.

• Journal of Distribution Science
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• v.16 no.3
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• pp.33-47
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• 2018

Purpose - The purpose of this study is to derive the performance improvement factors of courier corporations that operate global franchise systems as business strategies through their brands and to determine. Research design, data, and methodology - In the first study, 129 valid questionnaire sheets were analyzed. In the second study intended to determine whether the four performance improvement factors derived in the first study have positive effects on franchisees' business performance, 781 valid questionnaire sheets secured from six GDFFs were analyzed using AMOS analysis. Results - In the first study, four performance improvement factors were derived. In the second study, hypotheses regarding whether the performance improvement factors: leadership, communication, education and training, and brand, have positive effects on franchisees' business performance were tested, and as a result, one hypothesis was rejected and three hypotheses were adopted. Conclusions - The first and largest contribution of this study is that it derived performance improvement factors from GDFFs. The second contribution is that it determined whether the performance improvement factors that were derived have positive effects on franchisees' business performance with tests. The third contribution is that it created significant implications in terms of other studies, research value, and applications in industry fields.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.557-560
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• 2011

In the present paper, the sloshing resistance performance of an LNG carrier insulation system is evaluated by fluid-structure interaction (FSI) analysis. For this analysis, the arbitrary Lagrangian Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG motion of a KC-1 type LNG carrier cargo tank. In addition, the global-local analysis method is introduced to reduce computational time and cost. The global model is built from shell elements to reduce the sloshing analysis time. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.