• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.1-9
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• 2022

In this study, for development of the MDO (Multi Disciplinary Optimization) framework, the flight dynamic characteristic parameters of the ChangGong-91, a light aircraft, were extracted by an analytical method based on various semi-empirical methods, and the flight test method was compared and evaluated. The semi-empirical analysis methods for comparative subjects were the Perkins method, McCormick method, and Smetana method. The major stability/control derivatives and dynamic factors were calculated, using each method. As the comparison criteria, the flight test derivative estimates and dynamic factors were processed, using the output error method. Additionally, the flight characteristics of the light aircraft were analyzed and evaluated according to the provisions of the Korean Airworthiness Standard (KAS) of the Ministry of Land, Infrastructure and Transport, and MIL-F-8785C for the U.S. military.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3C
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• pp.97-104
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• 2009

In this study, artificial neural network was performed using the data of soils characteristic value, standard penetration test, and field permeability test of the 12 embankment that are located in the near Nak-dong and Kum-ho river to estimate the coefficient of field permeability of river embankment. The 89 data of total 108, 82% was used in learning step, and the other 19 data was used in estimation step. Also the results of generally used empirical equations were compared with those of artificial neural network for evaluation of application. As results, all of the coefficient of field permeability by empirical equation showed below 0.4 in terms of the coefficient of correlation with the measured values, but the coefficient of correlation of the predicted results by artificial neural network was up 0.8 in the all case. Therefore artificial neural network could predict more the precise field permeability well than the empirical equations.

• Asia pacific journal of information systems
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• v.6 no.2
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• pp.149-169
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• 1996

The Objective of this study is empirically investigating organizational/managerial factors affecting BPR implementation. The contributions of this research project are two-fold. First, this research project provides empirically tested CSFs and CFF of BPR implementation. Especially, the influence of the organizational culture, structure, and managerial support on BPR implementation were thoroughly investigated. Second, this research found the combined effects of CSF and CFF. Top management commitment, leadership style, and collaborative work environment were found to negate employee resistance to a reengineered process and lead to a successful BPR implementation, especially when the level of employee resistance is high.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.43-46
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• 1998

Internet is now changing the paradigms of traditional commercial activities. As more and more companies are actively involved in electronic commerce using Internet, it is becoming more imperative to understand the customers' perception of electronic commerce to foster healthy growth of Internet electronic commerce. However, research on customer satisfaction in electronic commerce has been scarce. This research investigates the factors affecting customer perception of electronic commerce and suggests the models and the results of the empirical study.

• Korea Journal of Hospital Management
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• v.12 no.4
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• pp.68-95
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• 2007

The purpose of this paper is to provide the comprehensive review of empirical investigations in strategy content in healthcare organizations. Given the absence of relevant reviews in assessing an external validity of strategy content research in the healthcare industry, the paper, by taking convergent view, discern two main streams of research in the school of content: (1) the strategy-structure-performance (SSP) contingent, and (2) competitive strategies which test the propositions that business strategy, industry structure (IO economics). Finally, the paper suggests some future direction for research in this area.

• Journal of the Korean Home Economics Association
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• v.33 no.2
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• pp.19-27
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• 1995

This paper discusses the bias that results from using nonrandomly selectd samples of consumer research. A two stage system (maximum likelihood probit analysis and ordinary least square analysis) is a solution to sample selection bias. Empirical results show that correcting for sample selection bias improves the validity of consumer research results.

• Korean Journal of Remote Sensing
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• v.28 no.4
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• pp.421-434
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• 2012

Colored Dissolved Organic Matter (CDOM) is one of the important components of optical properties of seawater to determine ecosystem dynamics in a given marine area. The optical characteristics of CDOM may depend on the various ecosystem and environmental variables in the sea and those variables may vary region to region. Therefore, the retrieval algorithm for determining light absorption coefficient of CDOM ($a_{CDOM}$) using satellite remote sensing reflectance ($R_{rs}$) developed from other region may not be directly applicable to the other region, and it must be validated using an in-situ ground-truth observation. We have tested 6 known CDOM algorithms (three Semi-analytical and three Empirical CDOM algorithms) developed from other regions of the world ocean with laboratory determined in-situ values for the East Sea using field data collected during seven oceanographic cruises in the period of 2009~2011. Our field measurements extended from the coastal waters to the open oceanic type CASE-1 Waters. Our study showed that Quasi-Analytical Algorithm (QAA_v5) derived $a_{CDOM}$(412) appears to match in-situ $a_{CDOM}$(412) values statistically. Semi-analytical algorithms appeared to underestimate and empirical ones overestimated $a_{CDOM}$ in the East Sea. $a_{CDOM}$(412) value was found to be relatively high in the relatively high satellite derived-chlorophyll-a area. $a_{CDOM}$(412) value appears to be influenced by the amount of chlorophyll-a in seawater. The outcome of this work may be referenced to develop $a_{CDOM}$ algorithm for the new Korean Geostationary Ocean Color Imager (GOCI).

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.267-273
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• 2017

This study was conducted to construct a empirical yield table for Pinus densiflora in real forest. Since existing normal yield tables have been derived by studying and analyzing communities in ideal environment for tree growth, those tables provide more over-estimated values than ones from real forest. Because of this, there are some difficulties to apply the tables to empirical forest except for normal forest. In this study, therefore, we estimated stand growth for real forest on P. densiflora as the representative species of conifers. We used 1,957 sample plot data of P. densiflora in central Korea from National Forest Inventory (NFI) system, and analyzed through estimation, recovery and prediction in order by using Weibull function as a diameter distribution model. Weilbull and Schumacher models were applied for estimating mean DBH and mean basel area and it was found that the site index for P. densiflora in central Korea ranges from 8 to 14 at reference age 30. According to site 12 in the stand yield table, the Mean Annual Increment (MAI) of P. densiflora was $4.42m^3/ha$ at 30 years of age. Compared to existing volume table constructed before, it is showed that MAI of this study were lower. According to the paired t-test that is conducted with the gap of volume values between normal forest and real forest by site index and age, the P-value was less than 0.001 which is recognized to have a statistically significant difference. Based on the results in this study, it is considered to be helpful for practical management and management policy on P. densiflora in central Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5351-5363
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• 2015

In literature, empirical studies investigating how stress affects HRQOL (health related quality of life) through physical activities are insufficient. In this sense, on the basis of KNHANES dataset for 2008 ~ 2013, we conducted an empirical study. Empirical results revealed that in the male group with stress experience, HRQOL was significantly influenced by age, household income, education, occupation, physical activity level. To do so, we adapt the chi-square analysis and the logistic regression analysis. Meanwhile, in the stress non-experience group, the low level activity has lower HRQOL than the high level activity(male: OR=1.15 p<0.001, female: OR=1.18 p<0.001). In the stress experience group, the male has the same pattern of effect compared to the stress non-experience group(OR=1.79 p<0.01). However, in the female, the low level activity has the higher HRQOL than the high level activity(OR=1.18 p<0.05). Therefore, we confirmed that physical activity has a different effect on HRQOL through stress experience.

• Journal of Venture Innovation
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• v.5 no.4
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• pp.91-108
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• 2022

This study is an empirical analysis regarding what kind of factors affect the intention to use autonomous vehicles. For the empirical analysis the research model was derived from value-based adoption model base and integrated some aspects that only autonomous vehicles have. At default variables of VAM are usefulness, enjoyment, technicality, perceived cost, some autonomous vehicle related variables were added, and those are convenience, safety, security, social influence. A survey was done in order to empirically analyze with this research model, and 216 valid survey answers were chosen to analyze. Empirical analysis was done by structural equation using AMOS24. The result of empirical analysis were as follows. Variables usefulness, enjoyment, safety, security had a significant positive effect on perceived value. Technicality and perceived cost had a significant negative effect of perceived value. In addition, security and social influence had no significant effect on perceived value. Furthermore, perceived value had significant positive effect on intention to use. Among the variables that came out to be significantly positive, the most influencing variable was safety, followed by convenience, perceived cost, enjoyment, usefulness and then technicality. In addition, the analysis of mediating effect of perceived value shows that usefulness, enjoyment, convenience, safety, technicality, perceived cost had mediating role towards intention to use. However, security and social influence had no siginificant mediating effect towards intention to use. Considering all these research results this study has provided theoretical and practical implications to researchers on the intention to use autonomous vehicles.