• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.4
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• pp.437-444
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• 2009

A bi-directional, multi-step numerical integrator is developed to determine the GPS (Global Positioning System) orbit based on a dynamic approach, which shows micrometer-level accuracy at GPS altitude. The acceleration due to the planets other than the Moon and the Sun is so small that it is replaced by the empirical forces in the Solar Radiation Pressure (SRP) model. The satellite orbit parameters are estimated with the least-squares adjustment method using both the integrated orbit and the published IGS (International GNSS Service) precise orbit. For this estimation procedure, the integration should be applied to the partial derivatives of the acceleration with respect to the unknown parameters as well as the acceleration itself. The accuracy of the satellite orbit is evaluated by the RMS (Root Mean Squares error) of the residuals calculated from the estimated orbit parameters. The overall RMS of orbit error during March 2009 was 5.2 mm, and there are no specific patterns in the absolute orbit error depending on the satellite types and the directions of coordinate frame. The SRP model used in this study includes only the direct and once-per-revolution terms. Therefore there is errant behavior regarding twice-per-revolution, which needs further investigation.

• Asian Journal for Public Opinion Research
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• v.12 no.1
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• pp.1-27
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• 2024

This study investigates the interplay between transformational leadership, personality, and work stress in public organizations, focusing on public servants in Putrajaya, Kuala Lumpur. Data from 702 public servants in Putrajaya, Kuala Lumpur, out of 800 distributed questionnaires, were analyzed. Rigorous analysis employed a structural equation model (SEM) with partial least squares (PLS-SEM) methodology. Our empirical analysis challenges the conventional belief of a positive correlation between transformational leadership and work stress in public organizations, revealing no direct link between transformational leadership and increased work stress in this context. Our study highlights a significant positive correlation between personality and work stress among public servants, emphasizing the role of individual personality characteristics in shaping work-related stress levels. Finally, personality emerged as a crucial mediator in the transformational leadership-work stress relationship, indicating that transformational leadership indirectly influences work stress through its impact on personality. This underscores the importance of considering personality as a mediating factor in understanding the transformational leadership-work stress dynamic in public organizations. In summary, our research provides insights into the relationship between transformational leadership, personality, and work stress in public organizations. These findings challenge conventional assumptions, emphasize individual differences in stress levels, and underscore the mediating role of personality in addressing work stress among public servants.

• Structural Engineering and Mechanics
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• v.65 no.5
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• pp.547-556
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• 2018

Based on the shaking table tests of a 1:3.52 scale one-bay and one-story ancient wooden structure, a simplified structural mechanics model was established, and the structural state equation and observation equation were deduced. Under the action of seismic waves, the damage rule of initial stiffness and yield stiffness of the joint was obtained. The force hammer percussion test and finite element calculations were carried out, and the structural response was obtained. Considering the 5% noise disturbance in the laboratory environment, the stiffness parameters of the mortise-tenon joint were identified by the partial least squares of singular value decomposition (PLS-SVD) and the Extended Kalman filter (EKF) method. The results show that dynamic and static cohesion method, PLS-SVD, and EKF method can be used to identify the damage degree of structures, and the stiffness of the mortise-tenon joints under strong earthquakes is reduced step by step. Using the proposed model, the identified error of the initial stiffness is about 0.58%-1.28%, and the error of the yield stiffness is about 0.44%-1.21%. This method has high accuracy and good applicability for identifying the initial stiffness and yield stiffness of the joints. The identification method and research results can provide a reference for monitoring and evaluating actual engineering structures.

• Korea Trade Review
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• v.41 no.2
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• pp.159-183
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• 2016

This study focuses on export venture firms in Daedeok Innopolis and examines the structural relationships among dynamic capability, technology commercialization competence, innovation performance, and competitive advantage. In particular, this study attempts to analyze dynamic capabilities that may affect technology commercialization competence, innovation performance, and competitive advantage. The development of the research model takes on a dynamic-capability view and is based on empirical studies regarding competitive advantage. A survey of 103 export venture firms was conducted from January 5, 2015, to February 4, 2015. A partial least squares structural equation model is used to test the relationships between constructs set in the study. The results of the study show that the dynamic capability of an export venture firm has a significant positive influence on the firm's technology commercialization competence, innovation performance, and competitive advantage. The study also finds evidence that the export venture firm's technology commercialization competence directly affects its innovation performance and competitive advantage. In addition, the findings indicate that the innovation performance of an export venture firm has a significant positive impact on the firm's competitive advantage. Overall, these findings contribute to a better understanding of the contexts in which dynamic capability represents a specific capability for export venture firms.

• Management & Information Systems Review
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• v.37 no.1
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• pp.19-40
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• 2018

The purpose of this study is to analyze the effects of a firm's dynamic capabilities measured by sensing, seizing, transforming, coordinating, and learning capabilities on its competitive capabilities, such as product quality, process flexibility, delivery speed, and low cost. The relationship among dynamic capabilities, competitive capabilities, and export firm performance is set up as a research model based on empirical studies related to the existing dynamic capability perspective and competitive capabilities. To test this research model, this study collected 102 samples of data using a questionnaire survey on both manufacturing and exporting firms. The partial least squares method is used and the following results are derived from an empirical analysis. First, dynamic capabilities have a positive effect on competitive capabilities, such as product quality, process flexibility, delivery speed, and low cost. Second, product quality and process flexibility have a positive effect on export firm performance. Third, unlike previous research results, this study finds that the competitive capabilities of a firm in the areas of delivery speed and low cost do not significantly affect its performance. These findings provide meaningful implications for export venture firms that need to acquire and maintain competitive advantage in a rapidly changing environment.

• Asia pacific journal of information systems
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• v.25 no.3
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• pp.597-625
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• 2015

Prior research has emphasized the significant effect of service orientation on organizational performance. However, little research on service orientation has been conducted in the financial field, including the investment management service industry in which high quality service for clients is required. In this paper, we propose a research model that centers on the concept of service orientation as a type of dynamic capability affecting firm performance. The research variables include job competency, risk management capability, operational capability, service orientation, and service performance. We assume that service orientation partially mediates the effects of risk management capability and operational capability on service performance. To test the model, we collected data from 391 fund managers in 86 teams (37 investment management companies) and analyzed it with partial least squares (PLS) method. Each of the 391 fund managers was asked to answer team level measures, which is effective for team level analysis. We find that job competency positively affects both risk management capability and operational capability, which in turn affect service orientation. Risk management capability and operational capability are assumed to directly affect service performance. However, risk management capability does not influence perceived service performance, whereas operational capability does affect it. This result indicates that risk management capability does not directly affect service performance. However, via service orientation, considering that risk management inconveniences customers and is geared to enhance service orientation, service performance is positively affected. Operational capability does not influence service orientation, whereas it affects perceived service performance. This result reveals that operational capability directly affects firm performance. As expected, service orientation significantly affects the service performance perception of fund managers. This study contributes to the literature by introducing service orientation to the financial industry and measures and tests team-level service performance. Our findings also provide insights to practitioners because to enhance team performance, managers must focus on service orientation in addition to operational capability.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.290-295
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• 2022

Background: Dried and red ginseng are well-known types of processed ginseng and are widely used as healthy food. The dried and red ginseng quality may vary with the storage period of raw ginseng. Therefore, herein, the effect of the storage period of fresh ginseng on processed ginseng quality was evaluated through multicomponent quantification with statistical analysis. Methods: A method based on ultrahigh performance liquid chromatography coupled to triple quadrupole mass spectrometry in multiple-reaction monitoring mode (UPLC-MRM-MS) was developed for quantitation of ginsenosides and oligosaccharides in dried and red ginseng. Principal component analysis and partial least squares discriminant analysis were conducted to evaluate the dynamic distributions of ginsenosides and oligosaccharides after different storage periods. Results: Eighteen PPD, PPT and OLE ginsenosides and nine reducing and nonreducing oligosaccharides were identified and quantified. With storage period extension, the ginsenoside content in the processed ginseng increased slightly in the first 2 weeks and decreased gradually in the following 9 weeks. The content of reducing oligosaccharides decreased continuously as storage time extending, while that of the nonreducing oligosaccharides increased. Chemical conversions occurred during storage, based on which potential chemical markers for the storage period evaluation of fresh ginseng were screened. Conclusion: According to ginsenoside and oligosaccharide distributions, it was found that the optimal storage period was 2 weeks and that the storage period of fresh ginseng should not exceed 4 weeks at 0 ℃. This study provides deep insights into the quality control of processed ginseng and comprehensive factors for storage of raw ginseng.