• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1101-1108
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• 2018

This study is a study of the school zone safety system of the platform part in which processing between device and the application, gateway function processing, and application and service function are cooperatively processed. The device part is the beacons that are supported when the student moves in the school zone. And the section of application is a service announcement that applies to smartphones. Finally, the children's protection area sign shows the number of students registered at the gateway. Gateways operate in two types. The first type is a gateway installed to identify the movement of elementary school students. The second type is a gateway to identify students who have passed through the front door of the school. The IoT platform handles various service functions, child protection area panel support and student counter processing functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1877-1893
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• 2009

Folksonomy is a user-generated taxonomy to organize information by which a user assigns tags to resources published on the web. Triadic datas that indicate relations of between users, tags, and resources, are created by collaborative tagging from many users in folksonomy-based system. Such the folksonomy data has been utilized in the field of the semantic web and web2.0 as metadata about web resources. In this paper, we propose FCA-based folksonomy data mining approach in order to extract the useful information from folksonomy data with various points of view. And we developed tool for supporting our approach. In order to verify the usefulness of our proposed approach and FMT, we have done some experiments for data of del.icio.us, which is a popular folksonomy-based bookmarking system. And we report about result of our experiments.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.1
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• pp.469-490
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• 2018

The purpose of this study is to analyze the status of interlibrary loan (ILL) services using data from its transection. While analyzing the ILL data, agenda to improve the quality of services was identified, and suggestions were made to address them. Three data sets including National Inter-Libary Loan data, National Library Statistics System data, and local inter-library loan system analysis data were collected and analyzed. The results indicate that the size of transaction in ILL is getting bigger. The local ILL, particularly, was expanded and actively used by people. Additionally, the type of library participating in ILL networks was diverse and the number of library was increasing. Finally, this study discussed the tool to measure the contribution of each library in ILL. The collection uniqueness and collaboration index of library as well as the ILL statistics should be considered in the process of the tool development.

• Journal of Aerospace System Engineering
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• v.13 no.5
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• pp.49-56
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• 2019

The Long-Term Sustainability (LTS) guidelines have attracted the most attention in the recent formation of international norms of behavior regarding outer space activities. The discussion began at the U.N. COPUOS in 2010. In June 2019, the 21 guidelines were finally adopted. The guidelines include international cooperation to promote and support the observation of the situation of orbiting objects, including space debris, for the purpose of preserving the space environment indefinitely, sharing data and forecasts on space weather, and announcing each country's space policy in accordance with international law. Some guidelines have failed to reach a consensus as the mitigation of space debris is often difficult to separate from space weapons tests. As plans for small satellites and Rendezvous and Proximity Operations have been projected for the future, it is expected that each countries' position on preserving the space environment will become more acute.

• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.1-9
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• 2019

An agent-based simulation is a popular simulation tool to solve various problems, such as stock market, population prediction, disease prediction, and development of a traffic system. As the agents are developed and researched in different application fields, the agent has a rigid structure and may not acceptable in different domains. As a result, it is a challenging problem to define a structure for an agent structure to reflect the researcher's simulation objective. This research proposes an extendable form for an agent and its modeling environment. In order to propose a standard structure, this study adopts system entity structure and discrete event system specification formalism. Also, this research introduces the SESManager which supports the proposed specification method. The proposed environment can hierarchically define the agent structure and synthesize the agent so that it can perform the agent simulation according to the user's simulation purpose.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.12
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• pp.311-318
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• 2021

With the rapid development of the Internet of Things(IoT) technology recently, multi-access edge computing(MEC) is emerged as a next-generation technology for real-time and high-performance services. High mobility of users between MECs with limited service areas is considered one of the issues in the MEC environment. In this paper, we consider a vehicle edge computing(VEC) environment which has a high mobility, and propose a task migration algorithm to decide whether or not to migrate and where to migrate using DQN, as a reinforcement learning method. The objective of the proposed algorithm is to improve the system throughput while satisfying QoS(Quality of Service) requirements by minimizing the difference between queueing delays in vehicle edge computing servers(VECSs). The results show that compared to other algorithms, the proposed algorithm achieves approximately 14-49% better QoS satisfaction and approximately 14-38% lower service blocking rate.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.130-137
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• 2021

The characteristics of forced vibration by an external excitation force having a frequency were analyzed according to the amplitude and frequency of the excitation force. To obtain displacement, velocity, and acceleration, numerical analysis was performed to obtain the frequency response, and in particular, each FRF(Frequency Response Function) was analyzed to reveal the location of the system natural frequency and excitation frequency in the frequency domain. In the vibration model caused by external excitation, the natural frequency and distribution of the surrounding excitation mode in displacement, velocity and acceleration FRF. The FRF was also shown in the power spectrum and FRF of real and imaginary parts. The external excitation force was approximated with the excitation force of a sine wave by giving the amplitude and frequency, the mode generated by this excitation force could be distinguished. After numerical analysis by changing the equivalent mass, damping and stiffness, the forced vibration response characteristics by external excitation force were systematically analyzed.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.147-155
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• 2021

This study covers the effectiveness of SNS utilization education for the elderly. Participants in the study conducted in-depth interviews with trainees currently participating in education and mentors of the same age who are working as assistive instructors. The study deals with whether SNS utilization education, which is considered difficult, can be a more valid class when an elderly person of the same age becomes a mentor and teaches a class. The results of the study said that it was a fun and rewarding education after using SNS for the elderly, free from fear of difficult devices due to the friendly consideration and empathy of the same age. If a mentor of the same age is used for education on SNS for the elderly, SNS education, which has been considered difficult and burdensome for the elderly, is expected to be activated with more flexible education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.632-637
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• 2019

The cable tray design of an offshore plant production design is to optimally arrange the 3D modeling so that the cable can be installed without interfering with the structural members and various outfit equipment, and it is performed using a PDMS (Plant design management system), which is a 3D CAD system for an offshore plant layout. This study reviewed the development of PML (Programmable macro language) for a PDMS supporting offshore plant cable tray design and examined the efficiency compared to the existing method. Cable tray design PML developed in this paper enables fully parametric design using electrical outfit template library, allowing a rapid response to frequent modifications due to design changes and minimizing repetitive work fatigue by reflecting the accumulated design experience. In addition, the developed system was applied to the offshore plant structure module and it improved the work efficiency by more than 50% compared to the existing method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.203-212
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• 2018

Quality requirements of manufactured products or parts are given in the form of specification limits on the quality characteristics of individual units. If a product is to meet the customer's fitness for use criteria, it should be produced by a process which is stable or repeatable. In other words, it must be capable of operating with little variability around the target value or nominal value of the product's quality characteristic. In order to maintain and improve product quality, we need to apply statistical process control techniques such as histogram, check sheet, Pareto chart, cause and effect diagram, or control charts. Among those techniques, the most important one is control charting. The cumulative sum (CUSUM) control charts have been used in statistical process control (SPC) in industries for monitoring process shifts and supporting online measurement. The objective of this research is to apply Taguchi's quality loss function concept to cost based CUSUM control chart design. In this study, a modified quality loss function was developed to reflect quality loss situation where general quadratic loss curve is not appropriate. This research also provided a methodology for the design of CUSUM charts using Taguchi quality loss function concept based on the minimum cost per hour criterion. The new model differs from previous models in that the model assumes that quality loss is incurred even in the incontrol period. This model was compared with other cost based CUSUM models by Wu and Goel, According to numerical sensitivity analysis, the proposed model results in longer average run length in in-control period compared to the other two models.