• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.65-72
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• 2022

In this paper, a zero trust-based complex biometric authentication was proposed in a passwordless environment. The linkage of FIDO 2.0 (Fast IDENTITY Online) transaction authentication platforms was designed in conjunction with metaverse. In particular, it was applied with the location information of a smart terminal according to a geomagnetic sensor, an accelerator sensor, and biometric information for multi-factor authentication(MFA). At this time, a FIDO transaction authentication platform was presented for adaptive complex authentication with user's environment through complex authentication with secondary authentication based on situational awareness such as illuminance and temperature/humidity. As a result, it is possible to authenticate secondary users based on zero trust with behavior patterns such as fingerprint recognition, iris recognition, face recognition, and voice according to the environment. In addition, it is intended to check the linkage result of the FIDO platform for complex integrated authentication and improve the authentication accuracy of the linkage platform for transaction authentication using FIDO2.0.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.175-184
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• 2022

This study investigates the impact of COVID-19 anxiety on dietary lifestyle and the effect of different dietary lifestyle on the intention to use drone food delivery services. A questionnaire survey was conducted among 356 Chinese consumers aware of drone food delivery services. Results show that First, COVID-19 anxiety significantly impacted dietary lifestyle, including health pursuit, safety pursuit, and convenience pursuit. Second, the dietary lifestyle of health pursuit, fashion pursuit, and convenience pursuit positively affected service perceptions, including perceived safety and perceived rapidity, perceived compatibility. The dietary lifestyle of taste pursuit positively associated with safety of drone food delivery service, while the dietary lifestyle of safety pursuit positively related to safety and rapidity of drone food delivery services. Third, the perceptions related to security, rapidity, and compatibility of drone food delivery services enhanced service usage intention. Results show that COVID-19 anxiety was positively associated with dietary lifestyle, influencing consumer attitudes toward drone food delivery services.

• Nutrition Research and Practice
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• v.17 no.1
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• pp.103-121
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• 2023

BACKGROUND/OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has affected the entire world population in many ways. This study aimed to analyze the patterns of changes in eating, food purchasing and preparation, physical activity, and subjective health after COVID-19 outbreak by various sociodemographic factors and to understand the factors associated with changes in subjective health. SUBJECTS/METHODS: A cross-sectional survey using a representative sample from Seoul was used for the analysis. The data collection was conducted from September to October 2020. A total of 3,833 citizens aged more than 18 years old participated in the Seoul Food Survey. Descriptive statistics and generalized ordinal logistic regression models were used to understand the changes in health behaviors, health indicators, and subjective general health by various socioeconomic status. RESULTS: It was shown that the changes in household income, food expenditure, food consumption and physical activities differed significantly by age, education, occupation, income, weight, and food security status. Low-income and food-insecure households were affected more severely by the pandemic. Older age, household food insecurity, income reduction, increased home cooking and frequency of having instant foods, decreased physical activity and weight gain were significant factors explaining worse perceived health during the COVID-19 pandemic. CONCLUSIONS: The results suggest that focusing on older populations and low-income families with food insecurity should be prioritized during infectious disease outbreaks. In addition, the role of physical activities and instant food consumption in explaining perceived health should be investigated further in this prolonged battle with the pandemic situation.

• Steel and Composite Structures
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• v.47 no.2
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• pp.253-267
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• 2023

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

• KNOM Review
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• v.22 no.1
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• pp.42-51
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• 2019

Recently, the amount of internet traffic is increasing due to the increase in speed and capacity of the network environment, and protocol data is increasing due to mobile, IoT, application, and malicious behavior. Most of these private protocols are unknown in structure. For efficient network management and security, analysis of the structure of private protocols must be performed. Many protocol reverse engineering methodologies have been proposed for this purpose, but there are disadvantages to applying them. In this paper, we propose a methodology for inferring a detailed protocol structure based on network trace analysis by hierarchically combining CSP (Contiguous Sequential Pattern) and SP (Sequential Pattern) Algorithm. The proposed methodology is designed and implemented in a way that improves the preceeding study, A²PRE, We describe performance index for comparing methodologies and demonstrate the superiority of the proposed methodology through the example of HTTP, DNS protocol.

• Korean Journal of Legislative Studies
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• v.27 no.3
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• pp.35-68
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• 2021

In the German federal election in 2021, the Social Democrats returned to power by a narrow margin and the Green Party emerged as the biggest winner. The two political parties took the lead by proposing policies that met the expectations of the people in the policies of climate and environment, pandemic response and health, and labor and social security. The Merkel effect did not play a significant role in the election, and it is highly likely that it will lead to government policy after the formation of a coalition. While the class cleavage in voting behavior has weakened, the generational cleavage has grown relatively large. Older people showed more support for the two major parties, while younger people showed higher support for the Green Party and the FDP. If the generational cleavage continues, it can be linked to the growth of the Green Party and the FDP, the continued weakening of the two major parties and the emergence of other new parties. In addition, the regional cleavage between the former East and West Germany still remain, which will affect the direction of the AfD and the Left and combine with other political cleavages. The 2021 German federal election can be said to be an election that heralds the realignment of the political party system.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.761-770
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• 2023

This study was conducted to identify factors affecting depression in the elderly using three-year Community Health Survey data from 2020, when COVID-19 was declared an epidemic. Differences in depression according to general characteristics, health behavior, subjective health level, and medical use among 220,921 elderly were analyzed using complex samples t-test and ANOVA, and multiple regression analysis was performed to identify factors affecting depression it was carried out. As a result of the study, the level of depression among elderly women was found to be high, with an average of 1.21±0.01 for elderly men and 1.74±0.02 for elderly women, and there was a difference in generation type, with depression being higher in the first generation for elderly men and the third generation for elderly women. Variables that had a great influence on depression were the experience of depression and perceived stress.

• Steel and Composite Structures
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• v.50 no.3
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• pp.265-280
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• 2024

The collapse behavior observed in single-story beam-column assembly (SSBCA) do not accurately represent the actual overall stress characteristic of multi-story frame structure (MSFS) under column loss scenario owing to ignoring the interaction action among different stories, leading to a disconnection between the anti-collapse behaviors of "components" and "overall structures", that is, the anti-collapse performance of frame structures with two different structural scales has not yet formed a combined force. This paper conducts a numerical and theoretical study to explore the difference of the collapse behaviors of the SSBCA and MSFS, and further to reveal the internal force relationships and boundary constraints at beam ends of models SSBCA and MSFS. Based on the previous experimental tests, the corresponding refined numerical simulation models were established and verified, and comparative analysis on the resistant-collapse performance was carried out, based on the validated modeling methods with considering the actual boundary constraints, and the results illustrates that the collapse behaviors of the SSBCA and MSFS is not a simple multiple relationship. Through numerical simulation and theoretical analysis, the development laws of internal force in each story beam under different boundary constraints was clarified, and the coupling relationship between the bending moment at the most unfavorable section and axial force in the composite beam of different stories of multi story frames with weld cover-plated flange connections was obtained. In addition, considering the effect of the yield performance of adjacent columns on the anti-collapse bearing capacities of the SSBCA and MSFS during the large deformation stages, the calculation formula for the equivalent axial stiffness at the beam ends of each story were provided.

• Korea Journal of Hospital Management
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• v.28 no.4
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• pp.62-72
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• 2023

Based on the basic ideology of health care, this study realized the seriousness of annual unmet medical need and conducted a study to confirm the relationship between the subjective perception of regional healthcare environment and unmet medical needs. The independent variable was classified into attitude 'satisfaction' and 'unsatisfaction' toward regional healthcare, and the dependent variable was classified as whether unmet medical needs occurred annually. Based on previous studies, the control variables were selected as demographic and socioeconomic characteristics that can affect the occurrence of unmet medical care annually and characteristics related to health behavior. Descriptive statistics were conducted for each variable on the extracted sample, and multivariate survey logistic regression analysis was conducted to confirm the association between variables. As a result, more unmet medical needs occurred annually than those who were satisfied with the medical services in the area where they lived. In addition, more unmet medical need occurred annually in "unsatisfied" households compared to households "satisfied" with local medical services. In residential areas, women live in "metropolis" and "rural areas" compared to "urban," women live in men, lower education levels, and poor subjective health levels, and less satisfied with local medical services. As such, the impact of environmental factors in the community on the use of health and medical services is one of the major areas of interest in the field of health science, such as health policy and social dynamics. Therefore, hospitals in each region need to make efforts in terms of hospital management to increase the overall satisfaction of medical services in the region by continuously monitoring the attitude of residents to achieve universal health security, and policymakers should also be interested and propose new policies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.456-477
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• 2024

With information technology's rapid development, the Internet faces serious security problems. Studies have shown that malware has become a primary means of attacking the Internet. Therefore, adversarial samples have become a vital breakthrough point for studying malware. By studying adversarial samples, we can gain insights into the behavior and characteristics of malware, evaluate the performance of existing detectors in the face of deceptive samples, and help to discover vulnerabilities and improve detection methods for better performance. However, existing adversarial sample generation methods still need help regarding escape effectiveness and mobility. For instance, researchers have attempted to incorporate perturbation methods like Fast Gradient Sign Method (FGSM), Projected Gradient Descent (PGD), and others into adversarial samples to obfuscate detectors. However, these methods are only effective in specific environments and yield limited evasion effectiveness. To solve the above problems, this paper proposes a malware adversarial sample generation method (PixGAN) based on the pixel attention mechanism, which aims to improve adversarial samples' escape effect and mobility. The method transforms malware into grey-scale images and introduces the pixel attention mechanism in the Deep Convolution Generative Adversarial Networks (DCGAN) model to weigh the critical pixels in the grey-scale map, which improves the modeling ability of the generator and discriminator, thus enhancing the escape effect and mobility of the adversarial samples. The escape rate (ASR) is used as an evaluation index of the quality of the adversarial samples. The experimental results show that the adversarial samples generated by PixGAN achieve escape rates of 97%, 94%, 35%, 39%, and 43% on the Random Forest (RF), Support Vector Machine (SVM), Convolutional Neural Network (CNN), Convolutional Neural Network and Recurrent Neural Network (CNN_RNN), and Convolutional Neural Network and Long Short Term Memory (CNN_LSTM) algorithmic detectors, respectively.