• Korea Trade Review
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• v.43 no.1
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• pp.177-197
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• 2018

This paper aims to analyze the effects of external uncertainty on the entry modes decision of multinational firms. On the basic assumption that the entry modes of the firms are dependent on ex-ante or ex-post perceived risk, we empirically analyzed the impacts of perceived risk factors on the investment patterns of firms. We found that the larger the population, the higher the level of GDP per capita, and the larger the trade volume as a ratio of GDP resulted in increased M&A FDI and greenfield FDI. The economic growth rate variables were found to be significantly positive effect on only greenfield entry mode. Regarding the main variables, lower levels of corruption and increased stability regarding political issues resulted in the host country receiving increased M&A investment. However, we found only a positive statistical significance of the political stability variable on the explaining greenfield FDI. Results show that M&A entry mode is affected by both corruption and political instability level. However, the greenfield FDI featuring sunk costs, seems more responsive to political instability.

• Korea Trade Review
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• v.42 no.6
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• pp.131-154
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• 2017

In international trade, transportation generally has the largest and direct impact on freight costs. However, it is also sensitive to external factors such as global economic conditions, global trade volume and exchange rate. Therefore, it is necessary to examine the relationship and influence of international trade in terms of external factors that affect the change of imports and exports by marine and air transportation through empirical analysis. In particular, the analysis of the impact of these external factors on marine and air transportation is an important topic when recent exchange rate changes are significant, and it is also necessary to analyze what transportation means are more sensitive to exchange rate changes. In this study, we use the Vector Error Correction Model to analyze the dynamic effects of changes in exchange rate and domestic and international economic conditions on marine and air transportation from January 2000 to March 2017. Respectively. Alos, Impulse response function and variance decomposition were examined.

• Korea Trade Review
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• v.48 no.2
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• pp.1-26
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• 2023

The purpose of this study is to demonstrate how internal capability adjustments made by subsidiaries in response to local market adaption and market changes, together with the use of internal and external networks, have an impact on the investment performance of such subsidiaries. From the empirical results, it was proven that the larger the extent of internal capability adjustment made by subsidiaries, and the more quickly and flexibly it is implemented, the more positive the investment performance is. The empirical findings also showed that in this process, the use of internal/external network embeddedness has a positive mediating impact on the investment performance. Additionally, the results of statistical analysis support the research hypothesis that external embeddedness has a greater mediating influence on multinational manufacturing companies entering Chinese market than internal embeddedness. It implies to the top managers of subsidiaries that the subsidiary should actively utilize external embeddedness to create a new locational competitive advantage in the local region, as well as develop a strategy to reduce foreignness costs such as cost of adapting to the local system.

• Advances in aircraft and spacecraft science
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• v.10 no.6
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• pp.495-519
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• 2023

The drone serves the customers not served by vans. At the same time, considering the safety, policy and terrain as well as the need to replace the battery, the drone needs to be transported by truck to the identified station along with the parcel. From each such station, the drone serves a subset of customers according to a direct assignment pattern, i.e., every time the drone is launched, it serves one demand node and returns to the station to collect another parcel. Similarly, the truck is used to transport the drone and cargo between stations. This is somewhat different from the research of other scholars. In terms of the joint distribution of the drone and road vehicle, most scholars will choose the combination of two transportation tools, while we use three. The drone and vans are responsible for distribution services, and the trucks are responsible for transporting the goods and drone to the station. The goal is to optimize the total delivery cost which includes the transportation costs for the vans and the delivery cost for the drone. A fixed cost is also considered for each drone parking site corresponding to the cost of positioning the drone and using the drone station. A discrete optimization model is presented for the problem in addition to a two-phase heuristic algorithm. The results of a series of computational tests performed to assess the applicability of the model and the efficiency of the heuristic are reported. The results obtained show that nearly 10% of the cost can be saved by combining the traditional delivery mode with the use of a drone and drone stations.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.596-603
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• 2021

Objective: To evaluate the feasibility and diagnostic performance of ultrasound (US)-guided fine-needle aspiration cytology and core-needle biopsy (US-FNAC/CNB) for the diagnosis of laryngo-hypopharyngeal masses. Materials and Methods: This was a single-center prospective case series. From January 2018 to June 2019, we initially enrolled 40 patients with highly suspicious laryngo-hypopharyngeal masses on laryngoscopic examinations. Of these, 28 patients with the mass involving or abutting the pre-epiglottic, paraglottic, pyriform sinus, and/or subglottic regions were finally included. These patients underwent US examinations with/without subsequent US-FNAC/CNB under local anesthesia for evaluation of the laryngo-hypopharyngeal mass. Results: Of the 28 patients who underwent US examinations, a laryngo-hypopharyngeal mass was identified in 26 patients (92.9%). US-FNAC/CNB was performed successfully in 25 of these patients (96.2%), while the procedure failed to target the mass in 1 patient (3.8%). The performance of US caused minor subclinical hematoma in 2 patients (7.7%), but no major complications occurred. US-FNAC/CNB yielded conclusive results in 24 (96.0%) out of the 25 patients with a successful procedure, including 23 patients with squamous cell carcinoma (SCC) and 1 patient with a benign mass. In one patient with atypical cells in US-FNAC, additional direct laryngoscopic biopsy (DLB) was required to confirm SCC. Among the 26 patients who received US-FNAC/CNB, the time from first visit to pathological diagnosis was 7.8 days. For 24 patients finally diagnosed with SCC, the time from first visit to the initiation of treatment was 25.2 days. The mean costs associated with US-FNAC/CNB was $272 under the Korean National Health Insurance Service System. Conclusion: US-FNAC/CNB for a laryngo-hypopharyngeal mass is technically feasible in selected patients, providing good diagnostic performance. This technique could be used as a first-line diagnostic modality by adopting appropriate indications to avoid general anesthesia and DLB-related complications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.3
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• pp.801-825
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• 2024

For Internet of Things, it is more preferred to have immediate access to environment information from sensor nodes (SNs) rather than from gateway nodes (GWNs). To fulfill the goal, mutual authentication scheme between user and SNs with session key (SK) negotiation is more suitable. However, this is a challenging task due to the constrained power, computation, communication and storage resources of SNs. Though lots of authentication schemes with SK negotiation have been designed to deal with it, they are still insufficiently secure and/or efficient, and some even have serious vulnerabilities. Therefore, we design an efficient secure authentication scheme with session key negotiation (eSAS2KN) for wireless sensor networks (WSNs) utilizing fuzzy extractor technique, hash function and bitwise exclusive-or lightweight operations. In the eSAS2KN, user and SNs are mutually authenticated with anonymity, and an SK is negotiated for their direct and instant communications subsequently. To prove the security of eSAS2KN, we give detailed informal security analysis, carry out logical verification by applying BAN logic, present formal security proof by employing Real-Or-Random (ROR) model, and implement formal security verification by using AVISPA tool. Finally, computation and communication costs comparison show the eSAS2kN is more efficient and secure for practical application.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.189-196
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• 2024

Frequent false positives alarm from the Intelligent Selective Control System have raised significant concerns. These persistent issues have led to declines in operational efficiency and market credibility among agents. Developing a new model or replacing the existing one to mitigate false positives alarm entails substantial opportunity costs; hence, improving the quality of the training dataset is pragmatic. However, smaller organizations face challenges with inadequate capabilities in dataset collection and refinement. This paper proposes an automatic human pose data collection system centered around a human pose estimation model, utilizing camera-based sensor fusion techniques and edge devices. The system facilitates the direct collection and real-time processing of field data at the network periphery, distributing the computational load that typically centralizes. Additionally, by directly labeling field data, it aids in constructing new training datasets.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.231-235
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• 2024

Marine debris entering through rivers negatively impacts the environment and poses a direct threat to human health. While barriers to prevent the outflow of floating debris are being installed, attention to their maintenance, especially the scheduling of garbage collection, is insufficient. Currently, maintenance relies on a sequential collection method based on the experience and know-how of field workers, with little systematic research to support it. In response, this study proposes a new feedback-based collection method based on YOLOv7, Monte Carlo simulation for trash collection analysis. The proposed method conducts collection based on the amount of trash detected by remote sensors such as CCTV, and the expected costs are statistically and economically compared using Monte Carlo Simulation (MCS). The results showed that the new collection strategy offers a cost advantage of about 63 % over the existing strategy.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.63-75
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• 2018

The purpose of this study is to analyze the effects of CCTV installation empirically in the economic and spatial aspects(crime displacement and diffusion effects of crime control benefits), targeting S city in Korea. In terms of economic effects, caused by CCTV installation(2012 and 2013), cost benefit analysis was conducted by means of CCTV installation costs, crime cases, and crime costs per case. The result shows that there is positive effect of 1.34(34%) in 2012. This is slightly higher than the previous study results in Korea(cost effectiveness 1.32), but a little lower than the USA cases(cost effectiveness 1.49). In the case areas in S city, the result proves that the new CCTV has gained economic profit through the crime reduction, compared to the installation expences. However, the cases in 2013 shows no economic profit effect. Secondly, an analysis was conducted in the spatial aspect(crime displacement and diffusion effects of crime control benefits) by using the analysis tool of crime displacement value called WDQ. The results are summarized as follows: The total crimes in three regions had crime diffusion effect but it was less than the direct effect, while in one region, displacement effect was found, but they were less than direct effect. In the case of theft and violence, CCTV had a positive effect, except for one region. The results of the analysis were totally different. Judging from this difference, it may conclude that the effects of CCTV are different by the types of crimes and the places of crimes. The results of this study is meaningful in that it examined and evaluated the effects of the CCTV by scientific and rational measurement tools where previous studies are not many. In addition, it has policy implication for the validity of CCTV and making effective installation plan for crime reduction and prevention.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.4
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• pp.167-178
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• 2021

The purpose of this study is to analyze the direct investment decision factors in the Kaesong Industrial Complex and Vietnam, and to contribute to the creation of domestic jobs and the revitalization of the inter-Korean economy. According to the analysis, most of the Kaesong Industrial Complex and Vietnamese investment companies are entering the complex for the purpose of utilizing cheap labor, cheap factory locations, sales/development of local markets, and bypass export production bases in third countries. This can be divided into production-efficient investors using differences in production price such as labor costs and market-oriented investors to sell and expand the local market, which seems to be consistent with global direct investment patterns such as Nike, Apple, and Amazon. However, even if the North Korea-U.S. denuclearization talks ease or lift sanctions, Vietnamese investors' willingness to invest in the North Korea has been most burdened by the possibility of closing special economic zones due to political risks. Last but not least, it is important to note that those willing to invest in North Korea are mostly smaller enterprises in textiles, sewing, footwear and leather industries-those that benefit from low-cost labor. Since their size is small, they need policy support in financing, especially in the early stages of their business. Even after they grow past the early stages, those without collateral would still need state guarantee letters to get financing. Thus, it is worth considering to use the Inter-Korean Cooperation Fund to compensate commercial banks for bad loan loss or for low-interest loans for smaller SMEs. The interviews with SMEs found that red-tape is one of the biggest difficulties they face. Thus, it is recommended that a one-stop service agency should be established to cover all processes and issues related to inter-Korean economic cooperation to eliminate redundancy and expediate government support for SMEs.