• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1574-1580
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• 2021

This paper designs and presents the results of an air network simulation radio transmission link applied with a multi-beam active phase array antenna simulator in a testbed system for verifying an air network currently underway as a technology development task. Using the Ku band, the Radio transmission link was designed in consideration of the link budget to satisfy the requirements for the system being developed. Considering short-distance links and long-distance links, the required EIRP and G/T performance scales of multi-beam repeaters and mission planes were applied to confirm the minimum and maximum link margins based on Eb/No. In this Radio Transmission Link design, the application analysis results such as rainfall availability are used to effectively establish standards when selecting the operating radius of the multi-beam relay system and related system standards.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.415-424
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• 2022

This study is a user experience research on the current usage of TV multiview and evaluating the usability. From traditional TV viewing to connecting laptop or mobile devices, the scope of using TV has expanded and evolved to multipurpose. Utilizing the multiview feature offers new TV experiences, but research on its usability has not been actively conducted yet. In this research, a case study and survey were held prior to usability testing to identify user needs and behavior of TV multiview. After reviewing the results, we ran a task-based usability testing and in-depth interview. As a result, users preferred different ways of accessing and using multiview based on their situation, and the current user interface needed improvement for easier, intuitive use. This study is expected to contribute to the development of improving user experience in TV multiview.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.216-238
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• 2023

In intelligent transportation systems, traffic management is an important task. The accurate forecasting of traffic characteristics like flow, congestion, and density is still active research because of the non-linear nature and uncertainty of the spatiotemporal data. Inclement weather, such as rain and snow, and other special events such as holidays, accidents, and road closures have a significant impact on driving and the average speed of vehicles on the road, which lowers traffic capacity and causes congestion in a widespread manner. This work designs a model for multivariate short-term traffic congestion prediction using SLSTM_AE-BiLSTM. The proposed design consists of a Bidirectional Long Short Term Memory(BiLSTM) network to predict traffic flow value and a Convolutional Neural network (CNN) model for detecting the congestion status. This model uses spatial static temporal dynamic data. The stacked Long Short Term Memory Autoencoder (SLSTM AE) is used to encode the weather features into a reduced and more informative feature space. BiLSTM model is used to capture the features from the past and present traffic data simultaneously and also to identify the long-term dependencies. It uses the traffic data and encoded weather data to perform the traffic flow prediction. The CNN model is used to predict the recurring congestion status based on the predicted traffic flow value at a particular urban traffic network. In this work, a publicly available Caltrans PEMS dataset with traffic parameters is used. The proposed model generates the congestion prediction with an accuracy rate of 92.74% which is slightly better when compared with other deep learning models for congestion prediction.

• Journal of Gifted/Talented Education
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• v.22 no.1
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• pp.173-196
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• 2012

The relationship of the teacher's recommendation and performance in gifted programs for the selected student by teacher's observations and nominations was analyzed in this study. The teacher's recommendation for 9 students selected by teacher's observations and nominations in institute of Science gifted Education of C National University of Education was analyzed for this purpose. The students were categorized into 4 groups depending on the description style and contents of the teacher's recommendation and 1 student was selected from each group for analysis. It was shown that the student, a1 who was described with cognitive characteristics of the gifted in episode style in the teacher's recommendation showed the aggressive task adherence and problem solving ability. The student, a2 who was described with emotional and social characteristics in episode style attended at the class in active attitude, but the student solved the problem by the assistance of the colleagues or the teacher. The student, b1 who was listed superficially in the teacher's recommendation showed the excellent problem solving ability based on the task adherence, experiment design ability and experiment manipulation ability. The student, b2 who was listed in superficially in the teacher's recommendation attended at the class in positive and upright attitude, but the task solving was lagged behind. It is concluded from the above results that the description on the cognitive area is necessary for the teacher's recommendation to have the usefulness in selecting gifted students.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.299-306
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• 2003

This paper formulates a problem of embedded real-time system re-engineering, and presents its solution approach. Embedded system re-engineering is defined as a development task of meeting performance requirements newly imposed on a system after its hardware and software have been fully implemented. The performance requirements nay include a real-time throughput and an input-to-output latency. The proposed solution approach is based on a bottleneck analysis and nonlinear optimization. The inputs to the approach include a system design specified with a process network and a set of task graphs, task allocation and scheduling, and a new real-time throughput requirement specified as a system's period constraint. The solution approach works in two steps. In the first step, it determines bottleneck precesses in the process network via estimation of process latencies. In the second step, it derives a system of constraints with performance scaling factors of processing elements being variables. It then solves the constraints for the performance staling factors with an objective of minimizing the total hardware cost of the resultant system. These scaling factors suggest the minimal cost hardware upgrade to meet the new performance requirement. Since this approach does not modify carefully designed software structures, it helps reduce the re-engineering cycle.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.325-339
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• 2021

The purpose of the study is to examine sports-related cognitive functions through a systematic review and to suggest effective instruments to measure the cognitive functions. The present study was conducted based on the systematic review and meta-analysis protocol-the PRISMA. Of 429 articles searched through keywords from 2008 to 2020, 45 articles that met the selection criteria were analyzed. It was revealed that athletes had better cognitive functions than non-athletes, that the higher the sports expertise was, the higher the cognitive functions, and that there were differences in cognitive functions according to the sport types. The primary cognitive functions related to sports performance summarized as executive functions (inhibition ability, cognitive flexibility), information processing speed, spatial ability, and attention. As tasks for measuring each cognitive function, a stop signal task for inhibition ability, a design flexibility task for cognitive flexibility, a simple and choice reaction time test for information processing, a mental rotation task for spatial ability, and an attention network test for attention are appropriate.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.363-376
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• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.The purpose of this study is to conduct a usability assessment to ensure that ergonomic design has been applied so that the ventilator central monitoring system can improve user satisfaction, efficiency, and safety. The rapid spread of COVID-19, which began in 2019, caused significant damage global medical system. In this situation, the need for a system to monitor multiple patients with ventilators was highlighted as a solution for various problems. Since medical device software is closely related to human life, ensuring their safety and satisfaction is important before their actual deployment in the field. In this study, a total of 21 participants consisting of respiratory staffs conducted usability test according to the use scenarios in the simulated use environment. Nine use scenarios were conducted to derive an average task success rate and opinions on user interface were collected through five-point Likert scale satisfaction evaluation and questionnaire. Participants conducted a total of nine use scenario tasks with an average success rate of 93% and five-point Likert scale satisfaction survey showed a high satisfaction result of 4.7 points on average. Users evaluated that the device would be useful for effectively managing multiple patients with ventilators. However, improvements are required for interfaces associated with task that do not exceed the threshold for task success rate. In addition, even medical devices with sufficient safety and efficiency cannot guarantee absolute safety, so it is suggested to continuously evaluate user feedback even after introducing them to the actual site.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.501-506
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• 2024

Humans have been shown to engage in multitasking behavior when searching for information on two or more topics or searching an information system at the same time. When processing multiple information tasks, priorities must be established as there are cognitive and physical limitations in processing multiple information tasks at once. The level of cognitive attention involved in multitasking behavior can vary depending on the complexity and importance of the information task. The objectives of this study are to understand: (a) the relationship between attention and information task prioritization behavior when people interact with information retrieval systems to find information for multiple tasks; (b) The effect of the degree of attention on information task prioritization behavior when people interact with an IR system to find information for multiple tasks. A review of the relevant literature shows that when people interact with information retrieval systems to find information for multiple tasks, their level of attention affects how they prioritize multiple information tasks. It should be noticed that people pay more attention to things they find interesting or important. Human-centered system design based on a conceptual understanding of multitasking is discussed.

• Journal of The Korean Association of Information Education
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• v.7 no.1
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• pp.80-90
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• 2003

In this paper, we designed the on-line Real-time Video Communication Learning System(RVCLS) for Web-based project learning and develop programs for test groups. And we have also analyzed how the Web-based learning using RVCLS change the students' perception on the classroom environment, using the WIHIC which is the classroom environment examination tool As a result, the Web-based project learning activities using RVCLS had affirmative effects on the eight areas of classroom environment such as students unity, teacher support, participation in class, spontaneity, exploration activities, task-oriented mind, cooperative attitude, and equality. Also, the web -based project learning using RVCLS is expected to help students enhance the self-directed learning capacity and increase abilities to use ICT.

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.555-563
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• 2011

Nowadays, demands with respect to applications based on geo-based information on mobile device such as smartphone and those based on open platform or open source have been increasing. This trend can be regarded as significant opportunities to widen application fields and to expand industry business cases using satellite imagery. However, it needs a different approach from conventional remote sensing researches. This work focuses on SAR among many kinds of geo-based data resources. First, an application for Interferometric SAR processing based on open source was implemented. And using this, InSAR data was processed and stored into database. When smartphone users at any places request InSAR results, they can receive InSAR information and concerned metadata on their device. An smartphone application for this task was designed and implemented in this study. This provides a practical way for SAR service for smartphone, and can apply to build mobile service system of complex and compound types of remote sensing resources and their derived contents.