• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.80-91
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• 2002

A general goal of the AT%(Asynchronous Transfer Mode) network is to support connect across various network. On ATM networks, ABR services are provided using the remained ban after allocation CBR and VBR traffic. Realtime services such as transmitting audio or video data may be provided using CBR ado VBR which have a constrained transmission delay, but in these cases, the communications bandwidth may be wasted. In this paper a simulation has been performed to compare and evaluate the performance between the ERICA(Explicit Rate Indicate Avoidance) and EPRCA(Enhanced Proportional Rate Control Algorithm) switches which use Explicit Rate switch algorithm for ABR switch. The variation of the ACR at the source end system, the queue length, the utilization rate of the link bandwidth and the share fairness at the transient and steady states are used as the evaluation criteria for the simulation. As a result of simulation, ERICA algorithm switch was ten times long compared to ERPCA switch to achieve assigned fair share. so EPRCA switch is superior to ERICA about load response. For Fair share and stability, ERICA switch is excellent to EPRCA switch.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.75-82
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• 2021

The number of traffic accidents is about 230,000, and due to non-recurring congestion and high driving speed, the number of deaths per traffic accident on freeways is more than twice compared to other roads. Currently, traffic information is provided based on nodes and links using the centerline of the road, but it does not provide detailed speed information. Recently, installing sensors for vehicles to monitor obstacles and measure location is becoming common not only for autonomous vehicles but also for ordinary vehicles as well. The analysis using large-capacity location-based data from such sensors enables real time service according to processing speed. This study presents an mapping method for individual vehicle data analysis based on space. The processing speed of large-capacity data was increased by using method which applied a quaternary notation basis partition method that splits into two directions of longitude and latitude respectively. As the space partition was processed, the average speed was similar, but the speed standard deviation gradually decreased, and decrease range became smaller after 9th partition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• The Journal of Information Systems
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• v.28 no.3
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• pp.1-23
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• 2019

Purpose This study examines the role of corporate image and privacy concerns in intention to use of online travel services using data from Vietnam. Design/methodology/approach The data collection was implemented to a student sample at the Foreign Trade University in Hanoi, which has a high concentration of young people who are interested in online travel in Vietnam. The paper based questionnaire was directly delivered to the respondents. After sorting to eliminate unfit samples, the number of responses was 541, which exceeds 500, the minimum number typically required. To test the hypotheses, we applied structural equation modeling (SEM) and Confirmatory Factor Analysis (CFA) was used to evaluate the reliability and validity of constructs in the model. We also used direct, indirect and total effect coefficient to evaluate the total impact of factors on the intention to use online services. Findings This study found that corporate image is positively associated to intention to use online services. It found a link between corporate image and privacy concerns, which suggests another way for firms to address their customers' privacy concerns; corporate image, which has received great attention in traditional offline sales channels, but not in online services, should receive higher attention in IS research. Online travel businesses, besides increasing ease of use, perceived usefulness and trust in their services, should focus on build a reliable corporate image, which can not only promote the service use but also help to eliminate users' the privacy concerns.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.207-214
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• 2019

The speed of technological development is increasing, and high-performance digital devices are spreading. Wired digital devices such as PCs have been optimized for existing wired environments, but needs are shifting away from the constraints of space and space to smart work that enables efficient work anywhere and anytime. The Smart Work System security design is needed to secure integrity and availability in the face of various security threats including physical threats (lost, stolen, and damaged terminals), technical threats (data theft, DoS: denial of service), and unauthorized access outside the wired environment. In this study, we analyzed smart work network systems, wired / wireless link systems, and digital smart devices. We also studied cyber-attack analysis and cybersecurity design methods for a Smart Work wired system and a future wireless system. This study will be used as basic data for building a secure Smart Work system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1071-1076
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• 2020

The importance of network separation is due to the use of the Internet with existing business PCs, resulting in an internal information leakage event, and an environment configured to allow servers to access the Internet, which causes service failures with malicious code. In order to overcome this problem, it is necessary to use network virtualization to separate networks and network interconnection systems. Therefore, in this study, the construction area was constructed into the network area for the Internet and the server farm area for the virtualization system, and then classified and constructed into the security system area and the data link system area between networks. In order to prove the excellence of the proposed method, a network separation construction study using network virtualization was conducted based on the basis of VM Density's conservative estimates of program loads and LOBs.

• Electronics and Telecommunications Trends
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• v.36 no.1
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• pp.54-63
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• 2021

Since the recent COVID-19 pandemic, countries have been strengthening trade protection for their security, and the importance of securing strategic materials, such as food, is drawing attention. In addition to the cultural aspects, the global preference for food produced in Korea is increasing because of the Korean Wave. Thus, the Korean food industry can be developed into a high-value-added export food industry. Currently, Korea has a low self-sufficiency rate for foodstuffs apart from rice. Korea also suffers from problems arising from population decline, aging, rapid climate change, and various animal and plant diseases. It is necessary to develop technologies that can overcome the production structures highly dependent on the outside world of food and foster them into export-type system industries. The global agricultural industry-related technologies are actively being modified via data accumulation, e.g., environmental data, production information, and distribution and consumption information in climate and production facilities, and by actively expanding the introduction of the latest information and communication technologies such as big data and artificial intelligence. However, long-term research and investment should precede the field of living organisms. Compared to other industries, it is necessary to overcome poor production and labor environment investment efficiency in the food industry with respect to the production cost, equipment postmanagement, development tailored to the eye level of field workers, and service models suitable for production facilities of various sizes. This paper discusses the flow of domestic and international technologies that form the core issues of the site centered on the 4th Industrial Revolution in the field of agriculture, livestock, and fisheries. It also explains the environmental awareness production technologies centered on sustainable intelligence platforms that link climate change responses, optimization of energy costs, and mass production for unmanned production, distribution, and consumption using the unstructured data obtained based on detection and growth measurement data.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.507-513
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• 2022

Objective : The goal of the following statewide age and gender-coordinated cohort study in Korea is to find out if there is a link between acute myocardial infarction (AMI) and Parkinson's disease (PD). Methods : Utilizing the National Health Insurance Sharing Service cohort, patient data were collected. Six thousand four hundred seventy-five individuals with PD were distinguished by utilizing the International Classification of Diseases 10 code G20 and have enrolled in the PD group. The number of participants decreased to 5259 after excluding 1039 patients who were hospitalized less than one time or who visited an outpatient clinic less than twice. Then, 26295 individuals were selected as part of the control group after case control matching was conducted through 1 : 5 age- and gender-coordinated matching. The Cox proportional hazard regression analysis and Kaplan-Meier method were utilized to analyze the likelihood of AMI in PD. Results : After controlling for age and gender, the hazard ratio of AMI in the PD group was 3.603 (95% confidence interval [CI], 2.837-4.577). After that, the following hazard ratio of AMI in the PD group was modified against for co-morbid medical disorders, resulting in 3.551 (95% CI, 2.795-4.511). According to a subgroup analysis, in males and females aged <65 and aged ≥65 and in the non-diabetes and diabetes, hypertension and non-hypertension, dyslipidemia and non-dyslipidemia subgroups, the AMI incidence rates were dramatically higher in the PD group compared to that of the control. Conclusion : Individuals with PD have a greater chance of AMI, according to this cross-national study.

• Korean Journal of Community Nutrition
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• v.28 no.4
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• pp.329-339
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• 2023

Objectives: This study aims to explore consumer awareness and usage patterns of local food in Jecheon city during the COVID-19 pandemic, contributing to the establishment of the Jecheon City Food Plan. Methods: Surveys were conducted from July 24 to August 24, 2021, using a combination of web-link and self-administered methods for adults living in Jecheon city (n = 250). Descriptive analysis, t-test, importance and satisfaction analysis (ISA) of local food choice attributes were performed using SPSS Statistics. Results: Participants prioritized freshness when purchasing agricultural products. The freshness of Jecheon local food was the selection attribute with the highest consumer satisfaction and could provide purchase motivation. Approximately 73.6% of respondents understood the concept of local food, and 70% were familiar with Jecheon's local food. Notably, 94.8% expressed an intention to purchase but held negative views on selling local food in other areas. The need to increase the supply of local food to vulnerable populations and public school catering was highly recognized. The ISA identified 'affordable price', 'delivery service', and 'product information' as areas requiring improvement. On the other hand, 'freshness of products', 'quality for the price', and 'support for local farmers and economy' were identified as attributes to be maintained and strengthened. Conclusions: Consumers in Jecheon city recognized local foods as more than just 'consumer goods'. Our findings suggest the need for further research on local food revitalization and more comprehensive local food planning to enhance consumer satisfaction.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.37-46
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• 2009

The movement of the MR loaded on the train is confined to the bidirectional movement along the rail. Therefore, the AR connected to the MR can use the address information of the neighboring ARs and configure CoA in advance before performing L2 and L3 handoff. The MR can acquire new CoA immediately from the present AR after the movement detection procedure. The performance analysis shows that the proposed scheme can provide CoA to the MR about 1.8(s) at minimum and 4.98(s) at maximum faster than the Stateless scheme because the proposed scheme does not carry out any additional CoA and DAD procedure unlike the Stateless scheme.