• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.83-90
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• 2008

Input shaping is an efficient tool to eliminate transient and residual vibration caused by motion of mechanical systems. However, the rise time of the systems tends to increase due to the presence of input shapers. This paper is concerned with the rise time reduction when using input shaping. To this end, this paper proposes an input shaper design method for an undamped single mode vibration system using a virtual mode, which is not an actual mode but reflected in the design process. The essence of the proposed method is to design a three-impulse input shaper as if a single mode system has two modes: one actual mode and one virtual mode. The natural frequency of the virtual mode is a design parameter to change the rise time of the system. This paper discusses the performance of the proposed input shapers by simulation.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.192-199
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• 2016

Mixed and augmented reality technique deals with mixing content between real world and virtual world containing augmented reality and augmented virtuality excluding of pure real and pure virtual world. In mixed and augmented reality, if a live actor and entity moving in real world can be embedded more naturally in 3D virtual world, various advanced applications such 3D tele-presence, 3D virtual experience education and etc can be serviced. Therefore, in this paper, we propose a standard model which is supporting to embed the live actor and entity into 3D virtual space, and to interact with each other. And also the natural embedding and interaction of live actor and entity can be performed based on the proposed model.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.487-493
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• 2018

In recent years, various virtual reality contents have been explosively developed, and the 'chance operation' in previous studies was mentioned. This study tries to implement the Step Sequencer in the virtual reality. Through the theoretical background analysis and case studies of virtual reality, three major experiential values such as Value of Overcoming Constraints, Value of Strengthening Experience, and Value of Creating New Experience were induced. A convergencestep sequencer with the presence and immersion elements was developed and presented so that the music contents divided into 4 areas can be understood easily controlled more conveniently while keeping the identity of the step sequencer. It is expected that various convergence VR contentscan be developed in the future studies.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.120-128
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• 2022

While online social interactions have been more prevalent with the increased popularity of Metaverse platforms, little has been studied the effects of facial expressions in virtual reality (VR), which is known to play a key role in social contexts. To understand the importance of presenting facial expressions of a virtual avatar under different contexts, we conducted a user study with 24 participants where they were asked to have a conversation and play a charades game with an avatar with and without facial expressions. The results show that participants tend to gaze at the face region for the majority of the time when having a conversation or trying to guess emotion-related keywords when playing charades regardless of the presence of facial expressions. Yet, we confirmed that participants prefer to see facial expressions in virtual reality as well as in real-world scenarios as it helps them to better understand the contexts and to have more immersive and focused experiences.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.70-77
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• 2003

가상환경에서의 실재감을 증대시키는 방법 중에 하나는 상호작용을 이용하는 방법이다. 즉, 사용자가 가상환경에 변화를 줄 수 있게 하여, 사용자와 가상환경 사이의 결속감을 통해, 사용자가 가상환경 속에 있는 듯한 느낌을 주는 것이다. 그러나, Architectural Walkthrough 혹은 Navigation 시스템은 기능적으로 가상객체와에 affordance 와 그 밖의 interactivity cue를 적용하여 사용자로 하여금 시각적으로만 상호작용감을 유발하게 하여, 사용자의 실재감을 높이기 위한 방법에 대한 것이다. 두 개의 가상환경에 대하여 아무런 visual cue가 없는 경우, 텍스트를 이용한 직접 표현 방법, 객체가 simulation 된 trace 그리고 affordance cue 등 총 4가지 방법들, 즉 총 8가지 실험 조합에서 사용자가 느끼는 상호작용성과 실재감을 측정하였는데 interactivity유도를 위한 간접적인 visual cue가 쓰였을 경우 통계적으로 유의하게 상호작용성 및 실재감이 증대하는 결과를 보여주었다. 이는 적은 모델링만의 노력으로, 실제 인터액션에 대한 구현 없이 가상환경에서 어느 정도의 실재감을 높일 수 있는 방법을 제시하고 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.309-316
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• 2017

In shuttle vans designed to transport children, the recognition of a child's approach and departure is very important. Ultrasonic sensors are generally used for a short distance around a vehicle. Although ultrasonic sensors are cheaper than other ADAS sensors, the number of sensors installed in a van should be optimized. In order to recognize the presence of a child around a shuttle van, this paper proposes the placement of ultrasonic sensors in the van. Considering the turning radius of the van and the distance from each sensor to a child, collision risk is classified as 'safe', 'warning', and 'danger'. The sensor placement and the recognition algorithm are verified in a virtual driving environment.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.2
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• pp.124-130
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• 2005

Obstacle avoidance of underwater robots based on a modified virtual force field algorithm is proposed in this paper. The VFF(Virtual Force Field) algorithm, which is widely used in the field of mobile robots, is modified for application to the obstacle avoidance of underwater robots. This Modified Virtual Force Field(MVFF) algorithm using the fuzzy lgoc can be used in moving obstacles avoidance. A fuzzy algorithm is devised to handle various situations which can be faced during autonomous navigation of underwater robots. The proposed obstacle avoidance algorithm has ability to handle multiple moving obstacles. Results of simulation show that the proposed algorithm can be efficiently applied to obstacle avoidance of the underwater robots.

• Journal of the Korea Computer Graphics Society
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• v.9 no.1
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• pp.19-27
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• 2003

Most interaction schemes in virtual environment are indirect in one way or another. ln particular, without a haptic device (which introduces its own problems due to its cumbersomeness), users must rely on visual (or/and aural) feedback, and can not directly appreciate the 3Dness of the interaction object even with stereoscopy. This causes a drop in object presence because people are used to, for instance, observing objects in one's hand, rotating and manipulating them with physical contact. To alleviate this problem, this paper proposes a hand-held cubic screen, named TangibleScreen, on which the appearance of the target interaction object is projected. We choose the Relief Texture Mapping as the rendering method to correctly generate the viewer dependent textures to be projected on the non-planar surfaces of the TangibleScreen.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.40-42
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• 2003

We implement a 3D virtual conference using IPv6 multicast protocol suites. PIM-SM(Protocol Independent Multicast-Sparse Mode) is chosen for multicast. To provide users with the virtual reality that they are actually participating in an academic conference, 3D interface is built on VRML. Various multicast activities such as join/leave of a user into/out of sessions are represented by enter/exit of corresponding avatar to maximize the "sense of presence."nce."quot;

• 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.