• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.1
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• pp.47-55
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• 2012

A structural health monitoring technique for locating impact position in a plate structure is presented in this paper. The method employs a single sensor and spatial focusing of time reversal (TR) acoustics. We first examine the TR focusing effect at the impact position and its surroundings through simulation and experiment. The imaging results of impact points show that the impact source location can be accurately estimated in any position of the plate. Compared to existing techniques for locating impact or acoustic emission source, the proposed method has the benefits of using a single sensor and not requiring material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in other ultrasonic testings of plate-like structures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.29-40
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• 2020

Korean firms have been vigorously searching and exploring overseas market opportunities through export and overseas investment. As of end of 2019, there were more than 80,000 Korean overseas subsidiaries all over the world. With Korean overseas direct investment increasing recently, it became one of the important issues for overseas investors to be successful in the global market. There are a lot of studies on factors influencing the performance of overseas subsidiaries such as 'firm' and 'country' factors. This study empirically examines subsidiary performance determinants with 'industry architectures' by using a sample of 292 overseas Korean firm subsidiaries. Industry architectures are the stable but evolving sets of rules and roles through which labor is divided within a sector. This article considers how industry architectures shape success in international expansion. Industry architectures differ between countries, are not necessarily technologically determined, shape firms' capabilities and their competitive environment, and constitute a distinct level of analysis. We extract antecedents of related theory and empirically test its impact with a survey of Korean firms expanding in emerging economies. We would say this is the first study which tries to focus on industry architectures with the performance of Korean overseas subsidiaries. We find that separability and similarity of industry architectures across countries and localization of subsidiaries are robust and important predictors of success in international expansion. Our results suggest that industry architectures should be added to firm and country as an intermediate level of analysis that helps explain success in international expansion. While we established a pattern, much more remains to be done. We focus on the success of foreign operations, but we do not consider the broader benefits of going abroad, such as the learning or network effects that accrue at the level of the entire firm. The next obvious question is whether the results would differ in the developed market context. These we leave for future research to consider.

• ETRI Journal
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• v.38 no.4
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• pp.634-644
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• 2016

Channel-based radio-frequency fingerprinting such as a channel impulse response (CIR), channel transfer function (CTF), and frequency coherence function (FCF) have been recently proposed to improve the accuracy at the physical layer; however, their empirical performance, advantages, and limitations have not been well reported. This paper provides a comprehensive empirical performance evaluation of RF location fingerprinting, focusing on a comparison of received-signal strength, CIR-, CTF-, and FCF-based fingerprinting using the weighted k-nearest neighbor pattern recognition technique. Frequency domain channel measurements in the IEEE 802.11 band taken on a university campus were used to evaluate the accuracy of the fingerprinting types and their robustness to human-induced motion perturbations of the channel. The localization performance was analyzed, and the results are described using the spatial and temporal radio propagation characteristics. In particular, we introduce the coherence region to explain the spatial properties and investigate the impact of the Doppler spread in time-varying channels on the time coherence of RF fingerprint structures.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.74-80
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• 2013

Generator faults does not happen more often than the transmission and substation facility faults. However, impacts on the power system by generator faults are very large. In order to minimize the impact of generator faults, generator protection and control system with high reliability is required. Most of the generator relay in generator protection and control system of large power plant of Korea is operated by imports from abroad. Accordingly, in order to accumulate source technology and increase the import substitution effect, localization of multi-function generator protection IED is being developed. This paper deals with the implementation of a multi-function prototype IED H/W, which can be command and data exchange through communication for measuring, monitoring, protection and control. And the IED specification, various relay elements, measurement elements, communication functions, module function, and test system for the prototype IED H/W are described.

• Biomolecules & Therapeutics
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• v.30 no.1
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• pp.64-71
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• 2022

Norovirus (NV) is the most common cause of viral gastroenteritis, with the potential to develop into a fatal disease in those who are immuno-compromised, and effective vaccines and treatments are still non-existent. In this study, we aimed to elucidate the molecular mechanism of the previously identified NV replication inhibitor utilizing a vinyl-stilbene backbone, AC-1858. First, we confirmed the inhibition of the NV RNA replication by a structural analog of AC-1858, AC-2288 with its exclusive cytoplasmic sub-cellular localization. We further validated the induction of one specific host factor, the phosphorylated form of heat shock factor (HSF)-1, and its increased nuclear localization by AC-1858 treatment. Finally, we verified the positive and negative impact of the siRNA-mediated downregulation and lentivirus-mediated overexpression of HSF-1 on NV RNA replication. In conclusion, these data suggest the restrictive role of the host factor HSF-1 in overall viral RNA genome replication during the NV life cycle.

• Korea Trade Review
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• v.46 no.2
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• pp.39-54
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• 2021

The purpose of this study is as follows. First we investigate the relationship between contact with foreign managers (CFM) of host country nationals (HCNs) working at MNC subsidiaries and their organizational identification with MNC (OIM). Second we examine the moderating effect of MNC subsidiary localization (MSL) on the relationship between CFM and OIM. For this purpose, we set hypotheses on the relationship among CFM, OIM, and MSL. To verify theses hypotheses, we conducted hierarchical regression analysis on the data from 374 HCNs in 56 MNC subsidiaries. The results of this study are as follows: Frist, CFM positively affects OIM. Second, there is a significant moderating effect of MSL on the relationship between CFM and OIM. Our findings have critical implications in that a subsidiary-level variable that has a significant impact on organizational identification with MNC is presented and in that specific managerial guidelines for subsidiaries can be drawn.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.123-129
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• 2019

Many transcription factors are involved in directing the growth of porcine oocytes. The localization and expression level of a given transcription factor often differ at each stage of early embryonic growth, which spans from fertilization to the formation of the blastocyst. A hallmark of the blastocyst stage is the separation of the endodermal and mesodermal ectoderm. The embryo's medium and its effects are known to be crucial during early development compared to the other developmental stages, and thus require a lot of caution. Therefore, in many experiments, early development is divided into the quality of oocyte and cumulus cells and used in experiments. We thought that we were also heavily influenced by genetic reasons. Here, we examined the expression patterns of five key transcription factors (CDX2, OCT4, SOX2, NANOG, and E-CADHERIN) during porcine oocyte development whose expression patterns are controversial in the pig to the literature. Antibodies against these transcription factors were used to determine the expression and localization of them during the early development of pig embryos. These results indicate that the expressions of key transcription factors are generally similar in mouse and pig early developing embryos, but NANOG and SOX2 expression appears to show speciesspecific differences between pig and mouse developing embryos. This work helps us better understand how the expression patterns of transcription factors translate into developmental effects and processes, and how the expression and localization of different transcription factors can crucially impact oocyte growth and downstream developmental processes.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.1
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• pp.69-74
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• 2016

A technique for improving estimation accuracy is introduced in order to locate the impact position of artillery shell during the weapon scoring test. Study on localization of impacts using acoustic measurement has been conducted and the usability of sensor array is verified with experiments. When the blast occurs above the ground in the firing range, the acoustic sensor above the ground can measure the directly propagated sound with the ground-reflected one. In this study, a method for reducing estimation error by using the reflection signal measurements based on the time difference of arrival method. Considering the reflection sound works as same as placing a virtual sensor symmetrically through the ground. This idea enables a virtual three-dimensional array configuration with a two-dimensional plane array above the ground as such. The time difference between the direct and the reflected propagations can be estimated using cepstrum analysis. Performance test has been made in the simulation experiment in the football size area.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.11-32
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• 1998

Globalization of economy has a significant impact on the organization of economic Space. This paper examines the concepts of globalization and localization, major trends of the changes in the organization of economic space in the Pacific rim, and the major processes of the changes. Intra-regional trade and foreign direct investments have increased considerably in the Pacific region with the progress of globalization during the last decade. Due to the Progress of globalization of economy in the Pacific rim, some growth triangles have extended their agglomeration area beyond the national boundaries and several new industrial districts have developed. The reorganization of the economic space in the Pacific rim has been resulted from industrial restructuring of NIEs, spatial division of labor along the commodity chains, and the formation of industrial networks within the region. The ‘cooperative network strategy’has been suggested to minimize the negative effects of glocalization and for the sustainable development in the Pacific rim.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.936-942
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• 2022

While indoor vehicle navigation is an essential component in large-scale parking garages of major cities, technical limitations and challenging propagation environments considerably degrade the accuracy of existing localization techniques. This paper proposes a proximity detection scheme using low-cost beacons where a handheld mobile device within a moving vehicle autonomously detects its approximate position and moving direction by only observing Received Signal Strength (RSS) values of beacon signals. The proposed approach essentially exploits the differential RSS technique of multi-directional beams to reduce the impact of the environment, vehicle, and mobile device. A low-cost multi-directional beacon prototype is developed using Bluetooth technology. The localization performance is evaluated using 96 beacons in an underground parking garage within an area of 394.8m×304.3m. Experimental results show that the 90th percentile of the average proximity detection error is 0.8m. Furthermore, our proposed scheme provides robust proximity detection performance with various vehicles and mobile devices.