• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.61-69
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• 2020

This study examined the braking characteristics of a heavy haul freight train with P4a distribution valves applied to domestic high-speed freight trains. A freight train was composed of 50 cars, which is twice the normal operation. A braking test was performed to confirm the characteristics of the braking of a heavy haul. The brake cylinder pressures were measured for emergency and service braking on the 1st, 10th, 20th, 30th, and 50th cars. Because the brake signal is transmitted to the pressure through the braking tube connected to the end of the train, the rear vehicle is braking later than the vehicle ahead. Therefore, it is necessary to predict the brake pressures in all cars in a train to supplement the results of the limited tests and calculate the braking distance. The pressure in each car was determined using empirical models of linear interpolation, stepwise, and exponential models, which provided reliable information. The predictive results of the empirical models were compared with the measured results, and the exponential model was predicted relatively accurately. These results are expected to contribute to the safe operation of heavy haul freight trains and can be used to predict the braking distance and calculate the level of impact between vehicles during braking.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.78-78
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• 2002

The role of heat shock proteins in shielding organism from environmental stress is illustrated by the large-scale synthesis of these protein by the organism studied to date. However, recent evidence also suggests an important role for heat shock protein in fertilization and early development of mammalian embryos. Effects of elevated in vitro temperature on in vitro produced bovine embryos were analysed in order to determine its impact on the expression of heat shock protein 70 (HSP70) by control and frozen-thawed after in vitro fertilization (IVF) or nuclear transfer (NT). The objective of this study was to assess the developmental potential in vitro produced embryos with using of the various containers and examined expression and localization of heat shock protein 70 after it's frozen -thawed. For the vitrification, in vitro produced embryos at 2 cell, 8 cell and blastocysts stage after IVF and NT were exposed the ethylene glycol 5.5 M freezing solution (EG 5.5) for 30 sec, loaded on each containers such EM grid, straw and cryo-loop and then immediately plunged into liquid nitrogen. Thawed embryos were serially diluted in sucrose solution, each for 1 min, and cultured in CRI-aa medium. Survival rates of the vitrification production were assessed by re-expanded, hatched blastocysts. There were no differences in the survival rates of IVF using EM grid, cryo-loop. However, survival rates by straw were relatively lower than other containers. Only, nuclear transferred embryos survived by using cryo-loop. After IVF or NT, in vitro matured bovine embryos 2 cell, 8 cell and blastocysts subjected to control and thawed conditions were analysed by semiquantitive reverse transcription polymerase chain reaction methods for hsp 70 mRNA expression. Results revealed the expression of hsp 70 mRNA were higher thawed embryos than control embryos. Immunocytochemistry used to localization the hsp70 protein in embryos. Two, 8-cell embryos derived under control condition was evenly distributed in the cytoplasm but appeared as aggregates in some embryos exposed frozen-thawed. However, under control condition, blastocysts displayed aggregate signal while Hsp70 in frozen-thawed blastocysts appeared to be more uniform in distribution.

• Korea Trade Review
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• v.42 no.5
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• pp.113-136
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• 2017

New product preannouncement through global supply chain management and international strategic alliances is a critical issue for firm's survive and gaining the competitive advantage in the global smart-phone market. To identify the impact of exploration alliance and exploitation alliance on the short-term's Firm Performance, respectively, This study implemented the event study and the cross sectional regression analysis, focusing on the case of Galaxy Note series. Research results identified that new technologies by exploration alliance and the existing technologies through exploitation alliance have a positive effect on the short-term's performance of vendors related. Furthermore, information for the new products showed higher the excess earning rate than information related to the existing technologies. This implies the firms that provides new technologies have a stronger innovative ability than the companies serving the existing technologies, recognizing as a positive signal in the market. Finally, this study implicates that new technologies by exploration alliance enhances innovative abilities from new product preannouncement, and is a critical variable that can determines whether to survive in the market.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.233-239
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• 2006

Most research for until at now link travel time were research for mean link travel time calculate or estimate which uses the average of the individual vehicle. however, the link travel time distribution is divided caused by with the impact factor which is various traffic condition, signal operation condition and the road conditional etc. preceding study result for link travel time distribution characteristic showed that the patterns of going through traffic were divided up to 2 in the link travel times. therefore, it will be more accurate to divide up the link travel time into the one involving delay and the other without delay, rather than using the average link travel time in terms of assessing the traffic situation. this study is it analyzed transit hour distribution characteristic and a cause using examine to the variables which give an effect at link travel time distribute using simulation program and determinate link travel time distribute ratio estimation model. to assess the distribution of the link travel times, this research develops the regression model and the fuzzy model. the variables that have high level of correlations in both estimation models are the rest time of green ball and the delay vehicles. these variables were used to construct the methods in the estimation models. The comparison of the two estimation models-fuzzy and regression model- showed that fuzzy model out-competed the regression model in terms of reliability and applicability.

• Phonetics and Speech Sciences
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• v.15 no.4
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• pp.91-100
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• 2023

Reverberation time (T60) is a typical acoustic parameter that provides information about reverberation. Since the impacts of reverberation vary depending on the frequency bands even in the same space, frequency-dependent (FD) T60, which offers detailed insights into the acoustic environments, can be useful. However, most conventional blind T60 estimation methods, which estimate the T60 from speech signals, focus on fullband T60 estimation, and a few blind FDT60 estimation methods commonly show poor performance in the low-frequency bands. This paper introduces a modified approach based on Attentive pooling based Weighted Sum of Spectral Decay Rates (AWSSDR), previously proposed for blind T60 estimation, by extending its target from fullband T60 to FDT60. The experimental results show that the proposed method outperforms conventional blind FDT60 estimation methods on the acoustic characterization of environments (ACE) challenge evaluation dataset. Notably, it consistently exhibits excellent estimation performance in all frequency bands. This demonstrates that the mechanism of the AWSSDR method is valuable for blind FDT60 estimation because it reflects the FD variations in the impact of reverberation, aggregating information about FDT60 from the speech signal by processing the spectral decay rates associated with the physical properties of reverberation in each frequency band.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.145-159
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• 2004

The conventional method for assessment of liquefaction potential proposed by Seed and Idriss has been widely used in most countries because of simplicity of tests. Even though various data such as stress, strain, stress path, and excess pore water pressure can be obtained from the dynamic test, especially, two simple experimental data such as the maximum deviatoric stress and the number of cycles at liquefaction have been used in the conventional assessment. In this study, a new detailed assessment for liquefaction potential to reflect both characteristics of real earthquake motion and dynamic soil resistance is proposed and verified. In the assessment, the safety factor of the liquefaction potential at a given depth of a site can be obtained by the ratio of a resistible cumulative plastic shear strain determined through the performance of the conventional cyclic test and a driving cumulative plastic shear strain calculated from the shear strain time history through the ground response analysis. The last point to cumulate the driving plastic shear strain to initiate soil liquefaction is important for this assessment. From the result of cyclic triaxial test using real earthquake motions, it was concluded that liquefaction under the impact-type earthquake loads would initiate as soon as a peak loading signal was reached. The driving cumulative plastic shear strain, therefore, can be determined by adding all plastic shear strains obtained from the ground response analysis up to the peak point. Through the verification of the proposed assessment, it can be concluded that the proposed assessment for liquefaction potential can be a progressive method to reflect both characteristics of the unique soil resistance and earthquake parameters such as peak earthquake signal, significant duration time, earthquake loading type, and magnitude.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1591-1604
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• 2023

In ocean color remote sensing, atmospheric correction is a vital process for ensuring the accuracy and reliability of ocean color products. Furthermore, in recent years, the remote sensing community has intensified its requirements for understanding errors in satellite data. Accordingly, research is currently addressing errors in remote sensing reflectance (R_rs) resulting from inaccuracies in meteorological variables (total ozone, pressure, wind field, and total precipitable water) used as auxiliary data for atmospheric correction. However, there has been no investigation into the error in R_rs caused by the variability of the water vapor profile, despite it being a recognized error source. In this study, we used the Second Simulation of a Satellite Signal Vector version 2.1 simulation to compute errors in water vapor transmittance arising from variations in the water vapor profile within the GOCI-II observation area. Subsequently, we conducted an analysis of the associated errors in ocean color products. The observed water vapor profile not only exhibited a complex shape but also showed significant variations near the surface, leading to differences of up to 0.007 compared to the US standard 62 water vapor profile used in the GOCI-II atmospheric correction. The resulting variation in water vapor transmittance led to a difference in aerosol reflectance estimation, consequently introducing errors in R_rs across all GOCI-II bands. However, the error of R_rs in the 412-555 nm due to the difference in the water vapor profile band was found to be below 2%, which is lower than the required accuracy. Also, similar errors were shown in other ocean color products such as chlorophyll-a concentration, colored dissolved organic matter, and total suspended matter concentration. The results of this study indicate that the variability in water vapor profiles has minimal impact on the accuracy of atmospheric correction and ocean color products. Therefore, improving the accuracy of the input data related to the water vapor column concentration is even more critical for enhancing the accuracy of ocean color products in terms of water vapor absorption correction.

• Asia Marketing Journal
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• v.15 no.4
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• pp.131-159
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• 2014

Corporate rebranding has been evident in the qualitative corporate rebranding studies as an imposed organizational change that induces mixed reactions and ambivalent attitudes among consumers. Corporate rebranding for the established and familiar corporate brands leads to more ambivalent attitudes as these companies represent larger targets for disparaging information. Consumers are found to hold both positive and negative reactions toward companies and brands that they are familiar with. Nevertheless, the imposed change assumption and ambivalent attitude, in particular corporate rebranding, have never been widely explored in the quantitative corporate rebranding studies. This paper aims to provide a comprehensive empirical examination of the ambivalence towards rebrandingrebranded brand attitude-purchase intention relationships. The author proposes that corporate rebranding for familiar corporate brands is a double-edged sword that not only raises the expectation for better performance, but also induces conflicted and ambivalent attitudes among consumers. These consumers' ambivalent attitudes are influenced by both the parent brands-related and general attitude factors which further affect their rebranded brand attitude and purchase intention. A total of 156 useable questionnaires were collected from Malaysian working adults; and two established Malaysian airfreight operators were utilized as the focal parent brands. The study found a significant impact of prior parent brand attitudes on ambivalence towards rebranding (ATR). The parent brand attitudes served as anchors in influencing how new information was processed (Mazaheri et al., 2011; Sherif & Hovland, 1961) and closely related to behavioral intention (Prislin & Quellete, 1996). The ambivalent attitudes experienced were higher when individuals held both positive and negative reactions toward the parent brands. Consumers also held higher ambivalent attitudes when they preferred one of the parent brands; while disliked the other brand. The study also found significant relationships between the lead brand and the rebranded brand attitude; and between the partner brands and ATR. The familiar but controversial partner brand contributed significantly to the ambivalent attitudes experienced; while the more established lead brand had significant impact on the rebranded brand attitude. The lead and partner brands, though both familiar, represented different meanings to consumers. The author attributed these results to the prior parent brand attitudes, the skepticism and their general ambivalence toward the corporate rebranding. Both general attitude factors (i.e. skepticism and general ambivalence towards rebranding) were found to have significant positive impacts on ATR. Skeptical individuals questioned the possibility of a successful rebranding (Chang, 2011) and were more careful with their evaluations toward 'too god to be true' or 'made in heaven' pair of companies. The embedded general ambivalent attitudes that people held toward rebranding could be triggered from the associative network by the ambiguous situation (Prislin & Quellete, 1996). In addition, the ambivalent rebranded brand attitude was found to lower down purchase intention, supporting Hanze (2001), Lavine (2001) and van Harreveld et al. (2009)'s studies. Ambivalent individuals were found to prefer delay decision making by choosing around the mid-ranged points in 'willingness to buy' scale. The study provides several marketing implications. Ambivalence management is proven to be important to corporate rebranding to minimize the ambivalent attitudes experienced. This could be done by carefully controlling the parent brands-related and general attitude factors. The high ambivalent individuals are less confident with their own conflicted attitudes and are motivated to get rid of the psychological discomfort caused by these conflicted attitudes (Bell & Esses, 2002; Lau-Gesk, 2005; van Harreveld et al., 2009). They tend to process information more deeply (Jonas et al., 1997; Maio et al., 2000; Wood et al., 1985) and pay more attention to message that provides convincible arguments. Providing strong, favorable and convincible message is hence effective in alleviating consumers' ambivalent attitudes. In addition, brand name heuristic could be utilized because the rebranding strategy sends important signal to consumers about the changes that happen or going to happen. The ambivalent individuals will pay attention to both brand name heuristic and rebranding message in their effort to alleviate the psychological discomfort caused by ambivalent attitudes. The findings also provide insights to Malaysian and airline operators for a better planning and implementation of corporate rebranding exercise.

• Management & Information Systems Review
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• v.36 no.1
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• pp.233-249
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• 2017

This study investigates the relation of managerial ability and firm performance in case of Chaebol in Korea. We employ non-financing firms at Korean markets for the period 2000-2015. Most important decision is made by the head of Chaebol which increases firm value eventually and he has such a strong dominant power that managers belongs to Chaebol have to follow mother firm's decision directions. So it is expected that managers belongs to Chaebol have to focus on long term performance rather than short term profits, which means they concentrate their managerial ability much on the firm value. Otherwise, managers in which non-Chaebol focus their ability on periodic accounting earnings. Thus, this study examines an empirical analysis on the relation of managerial ability and firm performance and the effect of Chaebol on the relation of managerial ability and firm performance. Empirical results are as follows: First, there exists a statistically significant positive relation between managerial ability and firm performance either short- or long-term. Second, we extend this relationship into Chaebol condition and find that managerial ability of Chaebol positively influences on the firm value which is long-term performance, rather than return on assets which is short-term performance. These results imply that managers belongs to Chaebol much concentrate their ability on long-term value which is differenciated from the case of non-Chaebol samples. Chaebol is an important issue in Korea because it dominates most of Korean local economy so its' impact from small changes on our economy is big enough. Our study examining the relationships between managerial ability of Chaebol and firm performance is meaningful and it is a good signal that they concentrate their ability much on the long-term value rather than short-term profits. We expect that the results of this study will provide the academic and practical references. This study will contribute to the future research in accounting through an analysis of managerial ability which is a new measure, Chaebol, and firm value.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.2
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• pp.1-18
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• 2020

This study is to identify the influence of major variables that affect the participation intention of securities type crowdfunding investors and how participation intention and perceived behavioral control affect investors' herd behavior including indirect effect analysis based on the theory of planned behavior. The ultimate purpose of this study is to understand the investment behavior of securities type crowdfunding investors and to help the relevant parties to develop various policies and business plans to revitalize the system and protect investors. An online survey was conducted on people who are interested or have experience in securities type crowdfunding to receive a total of 276 responses. Excluding outliers, a total of 261 responses were taken into account for the final analysis. For the data analysis, structural equation model analysis using SPSS 22.0 and Amos 22.0 statistical package was conducted. As a result, two of the major variables of the theory of planned behavior-attitude and subjective norm-have been found to have a positive effect on the participation intention of securities type crowdfunding investors. And after analyzing the indirect effect, the participation intention was found to play a mediating role between attitude, subjective norm and herd behavior. However, the perceived behavioral control presented as a major variable of behavioral intention in the theory of planned behavior showed that the effect on participation intention was statistically insignificant. Instead, it was found to have a direct positive effect on herd behavior. This is significant because it empirically confirmed that even if investors perceive securities type crowdfunding as easy to participate, perceived behavioral control does not seem to have a significant impact on participation intention because securities type crowdfunding is an investment in an early-stage business with a high risk of loss. On the other hand, the study has great significance in that it empirically confirmed that domestic securities type crowdfunding investors perceive the funding progress information provided by the platform as a signal and imitate many other investors, showing herd behavior when they actually make an investment. It is expected that this study will provide meaningful insights for the policy making of crowdfunding supervisory offices and platform operators by empirically identifying major variables that influence the participation intentions and herd behavior of domestic securities type crowdfunding investors.