• IEIE Transactions on Smart Processing and Computing
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• v.2 no.6
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• pp.357-366
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• 2013

Spectrum sensing, as a fundamental functionality of Cognitive Radio (CR), enables Secondary Users (SUs) to monitor the spectrum and detect spectrum holes that could be used. Recently, the security issues of Cognitive Radio Networks (CRNs) have attracted increasing research attention. As one of the attacks against CRNs, a Primary User Emulation (PUE) attack compromises the spectrum sensing of CR, where an attacker monopolizes the spectrum holes by impersonating the Primary User (PU) to prevent SUs from accessing the idle frequency bands. Energy detection is often used to sense the spectrum in CRNs, but the presence of PUE attack has not been considered. This study examined the effect of PUE attack on the performance of energy detection-based spectrum sensing technique. In the proposed protocol, the stationary helper nodes (HNs) are deployed in multiple stages and distributed over the coverage area of the PUs to deliver spectrum status information to the next stage of HNs and to SUs. On the other hand, the first stage of HNs is also responsible for inferring the existence of the PU based on the energy detection technique. In addition, this system provides the detection threshold under the constraints imposed on the probabilities of a miss detection and false alarm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2046-2052
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• 2016

Ramp metering is one of the most efficient and widely used control methods for an intelligent transportation management system on a freeway. Its objective is to control and upgrade freeway traffic by regulating the number of vehicles entering the freeway entrance ramp, in such a way that not only the alleviation of the congestion but also the smoothing of the traffic flow around the desired density level can be achieved for the maintenance of the maximum mainline throughput. When the cycle of the signal detection is larger than that of the system process, the density tracking problem needs to be considered in the form of the discrete-time system. Therefore, a discrete-time sliding mode control method is proposed for the ramp metering problem in the presence of both input constraint in the on-ramp and exogenous disturbance in the off-ramp considering the random behavior of the driver. Simulations were performed using a validated second-order macroscopic traffic flow model in Matlab environment and the simulation results indicate that proposed control method can achieve better performance than previously well-known ALINEA strategy in the sense that mainstream flow throughput is maximized and congestion is alleviated even in the presence of input constraint and exogenous disturbance.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.49-57
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• 2023

The purpose of this study is to explore how adolescents' psychological characteristics affect their sense of life safety according to gender. To this end, a survey was conducted on male and female high school students in six schools in the C area, and a total of 1,048 data were used for analysis. Differences in major variables according to gender were verified, and the effect of psychological characteristics on living safety awareness was analyzed through hierarchical multiple regression analysis. As a result of the analysis, depression, anxiety, type A characteristics, and the presence or absence of experience in accidents did not significantly affect life safety awareness in the male student group. On the other hand, in the female student group, anxiety and type A characteristics had a significant effect on life safety awareness. Anxiety negatively affects living safety awareness, and type A characteristics have been shown to have a positive effect on living safety awareness. The presence or absence of depression and accident experience did not significantly affect life safety awareness. The results of these studies suggest that gender differences should be considered in education to prevent life safety awareness and that education that reflects the psychological characteristics of adolescents is necessary.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.119-127
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• 2006

A non-destructive time domain approach to examine structural damage using parameterized partial differential equations and Galerkin approximation techniques is presented. The time domain analysis for damage detection is independent of modal parameters and analytical models unlike frequency domain methods which generally rely on analytical models. The time history of the vibration response of the structure was used to identify the presence of damage. Damage in a structure causes changes in the physical coefficients of mass density, elastic modulus and damping coefficients. This is a part of our ongoing effort on the general problem of modeling and parameter estimation for internal damping mechanisms in a composite beam. Namely, in detecting damage through time-domain or frequency-domain data from smart sensors, the common damages are changed in modal properties such as natural frequencies, mode shapes, and mode shape curvature. This paper examines the use of beam-like structures with piezoceramic sensors and actuators to perform identification of those physical parameters, and detect the damage. Experimental results are presented from tests on cantilevered composite beams damaged at different locations and different dimensions. It is demonstrated that the method can sense the presence of damage and obtain the position of a damage.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.761-767
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• 2009

The detection of target echoes in a sonar image is usually difficult since reverberation is originated by the returns reflected around the boundary and volumes. Under the scenario of the target presence around the reverberation, the detection performance of existing algorithms is degraded. Since they have a similar statistical features. But proposed detector gives improvement existing algorithms Under this scenario. In this paper, 4 segmentation contrast box algorithm using maximum contrast value is proposed based on statistical segmentation, which gives better detection performance in the sense of reducing false alarms. The simulations validate the effectiveness of the proposed algorithm.

• CELLMED
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• v.7 no.2
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• pp.7.1-7.3
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• 2017

Ok-jin Gong's hunchback dance is considered to be a strange dance in Korea. However, there have been no reports of the effects of music and dance therapy as a pain treatment. The aim of this article is to argue that watching and listening to the hunchback dance of Ok-jin Gong may have significant effects as a form of pain treatment. The creator of this style of dance suspected that dance in general can be an outlet for our inner emotions. Her dance in this case has received critical and complimentary reviews as well. However she has been cited as the main culprit behind the destruction of traditional dance forms in the Korean dance world. Nonetheless, her bewitching stage presence attracted much attention. She satirized the feelings of the under privileged' through music and dance. We tend to feel somehow relative poverty and small in the presence of a rich and successful man. On the other hand, the artist felt that it is the public who would be relatively comforted and satisfied in the presence of the weak and handicapped. A free spirit that makes us forget pain is the very essence of her dancing. Her dance and music sound as if she sublimated her sadness and ugliness, changing it to happiness and beauty. She puts herself in a low position and spreads a sense of freedom and relief to the world. Hence, the author felt that innumerable people have been comforted in these ways by her dance.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.44-55
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• 2014

The goal of 3D stereoscopy is not only to maximize positive experiences (such as sense of realism) by adding depth information to 2D video but to also minimize negative experiences (such as fatigue). This study examines the impact of different depth levels induced by adjusting 3D camera convergences on positive and negative experiences and finds an optimal parameter for viewers. The results show that there are significant differences among depth levels on spatial involvement, realistic immersion, presence, depth perception, screen transmission, materiality, shape perception, spatial extension and display perception. There are also significant differences for fatigue and unnaturalness. This study suggests that reducing the camera convergence angle of an object by $0.17^{\circ}$ behind the object is the optimal parameter in a 3D stereoscopic setting.

• Journal of Korea Multimedia Society
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• v.3 no.3
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• pp.224-233
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• 2000

An important feature of virtual reality is the facility for the user to move around a virtual environment in a natural and easily controlled manner, Navigation. Navigation involves changing the perspective of the user in the virtual environment (VE). Natural locomotion methods are able to contribute to a sense of presence and reality. This paper focuses on the navigation method in the virtual environment, one of the major interfaces for the interactivity between human and virtual environments in virtual reality circumstances and worlds. It proposes a new navigation method: Intelligent Cruise-Control Navigation (ICCN), which provides a natural and user-centered navigation method in virtual environment and can improve the reality and the presence. Intelligent Cruise-Control Navigation is composed of three major phases: Constant Velocity Navigation, Collision Detection and Avoidance, and Path Adjustment. The ICCN can reduce the user's fatigue and improve the user's presence and reality in the virtual environment. Through the experimental study it has been determined that the ICCN will be a natural, straightforward, and useful interface in VE.

• Cartoon and Animation Studies
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• s.22
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• pp.81-97
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• 2011

The technology of 'Virtual Reality' has placed in advanced tools for human beings' joy and anger together with sorrow and pleasure in our generation. It has recently tried in a variety ways to use as an implication for treatment in the field of Cognitive Psychology. Especially, it widely approaches to human in terms of that a sense of reality in a virtual world through the five senses should reinterpret the meaning of cognition in the real world. Based on this paradigm shift, it allows for new treatment using the technology of virtual reality. A typical example is a field of Therapy in order to overcome panic disorder. It has advantages that in particular development of flexible interaction technologies in a virtual space can lead patients to experience psychological environments rather than physical one. the interaction technology provides environments in which users' five senses can be actively stimulated, it is very useful that information from the experiences in the virtual world allows people to learn through real experiences by renewing potential energies, advantages of Virtual Reality Therapy can be customized treatment by depending on symptoms in patients with panic disorder and are capable of differentiate application for the cure at each stage. It is to treat by leading patients to get accustomed to environments and situations in real world through care process with each symptom and stage. It is helpful that based on A Human-Sensibility Ergonomics, technologies like immersive virtual reality equipment, force-relative feedback and stereophonic sound, and like stimulating the sense of smell make people to induce experiences by stimulating human's five senses. There are many advantages of immersion in virtual world in that the phenomenon such as challenge, interaction, reality, illusion, and cooperation is expanded. As an application for therapy by growing such augmented reality, virtual space and sharing of data through the Internet and also inexpensive its availability have recently expanded the base. There are other benefits of Virtual Reality Therapy offering active interaction environments for cognitive experience which can provide appropriately adjusted environments for patients who are hard to overcome the real situation because of phobia. In addition to that it is safe and economical and patients' confidentiality is assured. Moreover, due to the principles of applying real-time navigation the Virtual Reality Therapy makes modification and supplementation easier and also it can reduce cybersickness because of the supply of Lenticular allowing people to see stereoscopy without eyeglasses, which makes sense of presence clearer. On top of that due to the development of interactive technologies, it is becoming close to sense of reality similar to real world by leading users to navigate by themselves and to operate objects in a virtual space. This paper will therefore examine, although it is of limited, characteristics of application of virtual reality technology based on A Human-Sensibility Ergonomics used for treatment for a disorder. this paper will analyse a range of its application and problems and it will suggest the future possibilities.

• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.63-69
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• 2000

The majority of patients who present with muscle pain does not have a definable myopathic disorder in the usual sense, despite intensive evaluation. Currently, most of these individuals are diagnosed with the syndrome of fibromyalgia, a condition that has been discussed under a number of different names for approximately a century. Fibromyalgia is a form of nonarticular rheumatism characterized by widespread musculoskeletal aching and stiffness, as well as tenderness on palpation at charateristic sites, called tender points. The American College of Rheumatology in 1990 set criteria for the diagnosis of fibromyalgia as that includes at least 3 months of widespread pain and the presence of at least 11 of 18 specific tender points on examination.