• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.594-603
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• 2021

This study explored the moderating effects of task difficulty for flow, learning motivation, and interesting in distant PBL classes of pre-service teachers. For this, the research model was constructed by analyzing previous studies. The research model verification was conducted by 105 students of taking courses in the curriculum. The distant PBL used a real-time video conference system. Cooperative activities were carried out in real time. After the end of the distant PBL activity, the level of learning motivation, interesting, flow, and task difficulty perception were measured. The collected data were analyzed using a test of the structural model invariance across the groups using a structural equation model. This analysis verifies the difference in path coefficients between measurement models. The control effect of task difficulty was verified through the difference in path coefficient. As a result, it was verified that interesting mediates the influence of learning motivation on flow. And the moderating effect of the perceived task difficulty appeared on the path from learning motivation to interesting.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.463-468
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• 2022

COVID-19 is a complex disaster, not an infectious disease-level disaster, and it is difficult to respond with the existing disaster response management method. As a result, experiencing psychological stress and trauma such as 'Corona Blue' has emerged as a new social problem. This study examined the changes in non-face-to-face counseling services using ICT technology and the application cases of image, AI, and VR by companies as the transition to the digital economy accelerates. Based on this, disaster psychological recovery support services were considered to improve the psychological recovery and quality of life of the people after a disaster by establishing a more efficient counseling system and developing counseling services using ICT technology.

• Smart Media Journal
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• v.11 no.2
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• pp.25-30
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• 2022

With the recent development of device performance such as smartphones, cameras, and video cameras, it has become possible to obtain human biometric information from images and photos. A German hacker group obtained human iris information from high-definition photos and revealed hacking into iris scanners on smartphones. As high-quality images and photos can be obtained with such advanced devices, the need for a suitable security system is also emerging. Therefore, in this paper, we propose a method of automatically masking human iris information in images and photos using Haar Cascades and Blur models from openCV. It is a technology that automatically masks iris information by recognizing a person's eye in a photo or video and provides the result. If this technology is used in devices and applications such as smartphones and zoom, it is expected to provide better security services to users.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.325-333
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• 2006

Recently, in the case of observing the global environment, satellite remote sensing technology has been important. It's because satellite remote sensing is valuable for assessing relatively large areas. But now, small scale remote sensing techniques are needed which can be applicable to the detail investigation of plant tree areas which afforest land after the large scale construction of roads, dams and airports. In this study, we tried to develop and propose a lower altitude sensing technique which can be used in ground remote sensing by using a CCD camera. As a result of this investigation the following can be concluded: We recognized the transference characteristics of filters which were used in comparative tests about the four ground remote sensing devices. We also found that the near-IR camera could be used for an imaging spectral radiometer in the extraction of the vegetation index. Furthermore, we found that the vegetation index has varied hour by hour during the day of the experiment. Finally, we brought about an increase phase of the NDVI in a forest fire, which caused considerable damage, by developing new ground remote sensing technology.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.13-22
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• 2023

The purpose of this paper is to explore the impact of online problem-based learning (PBL) on learners' 4C competencies and learning experience. The results of the study showed that, first, online PBL had a statistically significant effect on learners' problem-solving skills, communication skills, and pre-service teacher efficacy. Second, learners were very satisfied with the online PBL experience and perceived it to be very beneficial to their learning and to themselves as preservice teachers. Third, learners perceived that the real-time video conferencing system and instant messenger were very helpful for successful online PBL. Fourth, regarding the important factors for successful online PBL, the participants in this study perceived that communication and sincerity are very important, and the role of the leader is also important, but personal intimacy among team members is relatively less important. Fifth, learners perceive that instructor feedback is very important for successful online PBL. Finally, the implications of this study are discussed along with suggestions for future research.

• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.640-655
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• 2014

Many of today's video systems have additional depth camera to provide extra features such as 3D support. Thanks to these changes made in multimedia system, it is now much easier to obtain depth information of the video. Depth information can be used in various areas such as object classification, background area recognition, and so on. With depth information, we can achieve even higher coding efficiency compared to only using conventional method. Thus, in this paper, we propose the 2D video coding algorithm which uses depth information on top of the next generation 2D video codec HEVC. Background area can be recognized with depth information and by performing HEVC with it, coding complexity can be reduced. If current CU is background area, we propose the following three methods, 1) Earlier stop split structure of CU with PU SKIP mode, 2) Limiting split structure of CU with CU information in temporal position, 3) Limiting the range of motion searching. We implement our proposal using HEVC HM 12.0 reference software. With these methods results shows that encoding complexity is reduced more than 40% with only 0.5% BD-Bitrate loss. Especially, in case of video acquired through the Kinect developed by Microsoft Corp., encoding complexity is reduced by max 53% without a loss of quality. So, it is expected that these techniques can apply real-time online communication, mobile or handheld video service and so on.

• Korean Security Journal
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• no.10
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• pp.243-272
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• 2005

All measures related to the safety of the casino facilities guarantee safety of facilities that are targets of security guards, protect lives and properties, minimize risks of artificial and natural disaster and crimes. In summary, plan for responding to safety and accidents should be developed not only for the casino facilities but also for the facilities of annexed buildings, and lives and properties of customers and employees. Determine areas in the casino facilities that are prone to accidents and set around-the-clock guard in the areas or maintain surveillance with CCTV and prevent accidents through continuous patrol. These are the most basic and the most important requirements in safety. In addition, casinos which prompt gambling are causing economic and psychological treats to families. To resolve these social issues, casinos have adopted limited entrance system. To support this system, new forms of machine security systems such as video automatic recognition system of fingerprint pattern recognition system should be adopted too. In addition, security guards in casino facilities need to instill themselves with a sense of ownership as well as a strong sense of mission to do the best for customer security and to protect the company assets and employees and manage accidents that could occur without notice. Security guards should do their best to enable manage accidents that could occur without notice. Security guards should do their best to enable tourists who are on the rise due to increase in advanced country-style tourism and leisurely activities to get the utmost satisfaction from the casinos, and as a leader of private security company, establish the foundation for security based on the characteristics of security in Korea.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.194-201
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• 2012

Moxibustion is utilized not only to cure disease but also to increase immunity. However, it may lead to undesired effects including severe pains(blisters and burns) because of the difficulty of controlling heat intensity. To overcome these problems we developed the RF heat stimulation system which can control stimulus. Also, we developed the RF stimulation protocol for effective heat transfer in subcutaneous tissue of rabbit. RF stimulator consists of a medical RF capacitive heating device, isolation probe, isolation plate, negative pressure control part and temperature measurement part. For the designed stimulus protocol, we measured the temperature distribution on epidermis and in subcutaneous(5mm, 10mm) area of rabbit during moxibustion. A stimulation protocol was designed by controlling the ON/OFF duty ratio, repeating number, and energy of applied pulse to get the temperature distribution similar with that by moxibustion. In results, the correlation coefficients between temperature distribution by moxibustion and that of stimulator were 95% and 91% from 5mm and 10mm thick respectively. However, temperature distribution on epidermis by stimulator was remarkably lower than that of the moxibustion. Finally, the RF stimulation system showed that it can not only transfer effectively heat similar with moxibustion to the subcutaneous area, but also the influence by unwanted side effects can be minimized.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.1-8
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• 2004

The final goal of this research is to establish the relative dangerousness D/B for factors on seakeeping performance. This D/B is, essential to develope the seakeeping performance evaluation system built-on-ship. The system is composed of the apparatus for measuring a vertical acceleration to be generated by the ship's motions, computer for calculating the synthetic seakeeping performance index and monitor for displaying the evaluating diagram of navigational safety of ship. In this paper, a methodology on the establishment of the relative dangerousness D/B for factors on seakeeping performance is presented by a numerical simulations, playing an important role on the algorithm of the program for calculating the synthetic seakeeping performance index. Finally, It is investigated whether the relative dangerousness D/B can be realized an accurate values according to the loading conditions, weather conditions, wave directions and present ship's speed of a model ship.

• Journal of Internet Computing and Services
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• v.3 no.1
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• pp.81-90
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• 2002

Large-scale distributed applications based on Internet and client/server applications have to deal with series of problems. Load balancing, unpredictable communication delays, and networking failures can be the example of the series of problems. Therefore. sophisticated applications such as teleconferencing, video-on-demand, and concurrent software engineering require an abstracted group communication, CORBA does not address these paradigms adequately. It mainly deals with point-to-point communication and does not support the development of reliable applications that include predictable behavior in distributed systems. In this paper, we present our design, implementation and performance analysis of the group communication using the CORBA-ORB. JAVA-RML and Socket based on distributed computing Performance analysis will be estimated latency-lime according to object increment, in case of group communication using ORB of CORBA the average is 14.5172msec, in case of group communication using RMI of Java the average is 21.4085msec, in case of group communication using socket the average is becoming 18.0714msec. Each group communication using multicast and UDP can be estimated 0.2735msec and 0.2157msec. The performance of the CORBA-ORB group communication is increased because of the increased object by the result of this research. This study can be applied to the fault-tolerant client/server system, group-ware. text retrieval system, and financial information systems.