• Smart Media Journal
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• v.12 no.2
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• pp.15-26
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• 2023

Due to the global COVID-19 pandemic, which has led to a shift towards remote work, the frequency of external access to important internal resources by companies has increased exponentially, exposing them to various security threats. In order to address these access security issues, ZTA (Zero Trust Architecture) has gained attention. ZTA operates on the principle of not trusting external or internal users, and manages access authentication and authorization strictly according to pre-established policies. This paper analyzes the definition of ZTA and key research trends, and summarizes different ZTA solutions for each company.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.571-578
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• 2022

Objective: Cognitive-motor trainings had a positive impact on cognitive function and dual-task trainings led to improvements of global cognitive function. The brain activity of the prefrontal cortex (PFC) is another indicator that can infer cognitive function. This study aims to confirm the usability of the interactive system cognitive-motor training program and the changes in the prefrontal cortex through training. Design: Cross-sectional study Methods: In this study, two cognitive tasks were randomly applied to 20 adults as cognitive-motor training using an interactive system, and the same task was performed using the original method. During all tasks, the brain activity of the prefrontal cortex was measured by the change in oxyhemoglobin (HbO) in real-time using Functional Near-Infrastructure. After performing the tasks, the usability of the developed interactive system was evaluated by a usability questionnaire which consists of five items, and each item consists of a 7-point Likert scale that responds from 1 point to 7 points. Results: The HbO levels were increased during cognitive task performance than at the resting phase. And evaluating the usefulness of the interactive system, a questionnaire result showed that it would be useful for cognitive-motor programs. Conclusions: The cognitive-motor training using the interactive system increased the activity of the prefrontal cortex, and the developed wearable sensor-based interactive system confirmed its usefulness.

• Smart Media Journal
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• v.13 no.2
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• pp.129-135
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• 2024

In this paper, we propose a new approach that enhances the continuous optimization performance of the MAP-Elites algorithm. The existing self-referencing MAP-Elites algorithm employed the "DE/rand/1/bin" operator from the differential evolution algorithm, which, due to its lack of rotational invariance, led to a degradation in optimization performance when there were high correlations among variables. The proposed algorithm replaces the "DE/rand/1/bin" operator with the "DE/current-to-rand/1" operator. This operator, possessing rotational invariance, ensures robust performance even in cases where there are high correlations among variables. Experimental results confirm that the proposed algorithm performs better than the comparison algorithms.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.25-38
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• 2021

The aim of this study is to protect workers and pedestrians from accidents at night or bad weather by attaching optical fiber to existing safety clothing that is made only with fluorescent fabrics and retroreflective materials. A safety vest was designed and manufactured by applying optical fiber, and energy-harvesting technology was developed. The safety vest was designed to emit light using the automatic flashing of optical fibers attached to the film, and an energy harvester was manufactured and attached to drive the light emission of the optical fiber more continuously. As a result, first, the vest wearer' body was recognized from a distance through the optical fiber and retroreflection, which helped prevent accidents. Thus, this concept helps in saving lives by preventing accidents during night-time work on the roadside or activities of rescue crew and sports activities, or by quickly finding the point of an accident with a signal that changes the optical fiber light emission. Second, to use the wasted energy, a piezoelectric-element power generation system was developed and the piezoelectric-harvesting device was mounted. Potentially, energy was efficiently produced by activating the effective charging amount of the battery part and charging it auxiliary. In the existing safety vest, detecting the person wearing the vest is almost impossible in the absence of ambient light. However, in this study, the wearer could be found within 100 m by the light emission from the safety vest even with no ambient light. Therefore, in this study, we will help in preventing and reducing accidents by developing smart safety clothing using optical fiber and energy harvester attached to save lives.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.66-75
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• 2010

We proposed an occupant sensing system using single video camera and ultrasonic sensor for the advanced airbag. To detect the occupant form and the face position in real-time, we used the skin color and motion information. We made the candidate face block image using the threshold value of the color difference signal corresponding to skin color and difference value of current image and previous image of luminance signal to gel motion information. And then it detects the face by the morphology and the labeling. In case of night without color and luminance information, it detects the face by using the threshold value of the luminance signal get by infra-red LED instead of the color difference signal. To evaluate the performance of the proposed occupant detection system, it performed various experiments through the setting of the IEEE camera, ultrasonic sensor, and infra-red LED in vehicle jig.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.741-743
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• 2017

The visible light communication is a communication method of outputting binary data based on the illumination threshold value at the light receiving diode of the receiving unit, when the LED of the transmitting unit transmits light. However, separate receiver is necessary to receive the optical signal, there is a problem that a device not equipped with such a receiver can not utilize visible light communication. To solve this problem, this paper proposes a portable visible light receiver applicable to devices using USB OTG. Implemented portable visible light receiver converts the binary data received from the LED into a character string of ASCII code and transmits it to another device. Through data transmission experiments using smart phone confirmed that it is possible to transmit ASCII codes in the proposed method.

• Korean Journal of Optics and Photonics
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• v.34 no.2
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• pp.45-52
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• 2023

In this study, we have investigated the effect of photobiomodulation (PBM) on corneal wound healing, using a low-power light-emitting diode (LED) at different wavelengths. We found that LEDs with wavelengths ranging from 623 to 940 nm had no significant cytotoxic effects on corneal epithelial cells. The effect of PBM on promoting cell migration was analyzed by scratch assay, and it was found that PBM at 623 nm significantly increased cell migration and promoted wound healing. Furthermore, the expression of genes related to cell migration and wound healing was analyzed, and it was found that PBM at 623 nm upregulated the expression of the genes FGF-1 and MMP2, which are known to promote cell proliferation and extracellular matrix degradation. These findings suggest that PBM with low-powered light at specific wavelengths, particularly 623 nm, could be utilized to treat corneal injury.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.787-797
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• 2017

In this study, we investigated the features of using smart devices in socioscientific issues (SSI) debate classes. Twenty-seven high school students in Gyeonggi-do participated in this study. The processes of the SSI debate classes with smart devices were classified into five stages: data searching, data sharing, summary and organization of data, debate in the classroom, and online debate. Then some features at each stage were identified. It was found that they collected self-directed and in-depth data while reflecting their knowledge and experience, and selected data which were easy to understand at the stage of data searching. The specificity and validity of the evidences gathered and the clarity of the sources were improved at the stage of data sharing, although they shared more data offline than online. They organized their data by using paper rather than smart devices at the stage of summary and organization of data. Most of them failed to use the summary in debate. They argued and refuted based on concrete grounds at the stage of debate in the classroom, which raised students' interest in debate and led students to participate actively. At the stage of online debate, they were able to rearrange and review the arguments of both sides, and the participation of the students who were passive in classroom debate was enhanced. Based on these results, we suggest some effective teaching methods for SSI debate classes using smart devices.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.11
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• pp.205-210
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• 2014

This is concerned with the technology to display the design on Porcelain and adjust malfunction for moving effect and light intensity by curator. More precisely, the technology makes it possible that the porcelain is connected to Light module which is the device for controlling light emission and rotating rolling plate, etc that are connected to LED light module, optical fiber and controller that is for scenario from the given storytelling. In addition, with a WiFi portable device (Smart-phone, other mobile device). equipped with a scenario programs, information for operation, failure and malfunction can be obtained and analyzed in real-time, and menu color and alarm is alerted when the displaying design is in abnormal status, which makes the early reactions to the status. Furthermore, the collected data can be sent through WiFi network to the device and PC managed by the curator specialized in managing the design on the Porcelain, thus the technology could help the curator who have less knowledge about moving pattern on the Porcelain. There is always a possibility of malfunction due to various condition that are caused by wring-harness when modules are wired-connected. In this research, in order to overcome this problem, we propose a system configuration that can do monitoring and diagnosis with a device for collecting data from LED control module, Light emission sensor and a personal WiFi device. Also, we performed connection between optical Fiber and LED and interlock for the system defined by the definition for information and storytelling scenario.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4545-4553
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• 2014

Mobile GPU has led to the rapid development of smart phone graphic technology. Most recent smart phones are equipped with high-performance multi-core GPU. How a multi-core mobile GPU can be utilized efficiently will be a critical issue for improving the smart phone performance. On the other hand, most current research has focused on a single-core mobile GPU; studies of multi-core mobile GPU are rare. In this paper, the job scheduling patterns and the efficiency of multi-core mobile GPU are analyzed. In the profiling result, despite the higher number of GPU cores, the total processing time required for certain graphics applications were increased. In addition, when GPU is processing for 3D games, a substantial amount of overhead is caused by communication between not only the CPU and GPU, but also within the GPUs. These results confirmed that more active research for multi-core mobile GPU should be performed to optimize the present mobile GPUs.