• Journal of Korea Society of Industrial Information Systems
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• v.25 no.3
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• pp.31-38
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• 2020

In this paper, we compare and analyze smart technologies and present six obstacle detection features to help visually impaired people walk. Traditionally, visually impaired people walk with the white cane or a guide dog. With the development of IoT technology, various smart walking aids systems have been developed. Those intelligent walking aids systems have obstacle-detecting systems and route-guidance systems. Many researchers are developing the walking aids system, which detects an obstacle and provides the obstacle information by haptic feedback. Also, they are designing the database server system to share the obstacle information. Particularly the composed system can quickly give an obstacle-avoidance route using shared obstacle information. Smart walking aids systems for visually impaired people will advance more rapidly by applying machine learning and intelligent systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5684-5688
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• 2012

This paper aims to design the leaf spring of high fatigue life which guides the moving part of the horizontal linear vibrating actuator. The vertical linear vibrating actuator has been used as the vibration device for haptic and alarm function on smart phone. However, the vibrating actuator has a major cause on the limitation to make smart phone slim because of its own characteristic of vertical direction vibration. The horizontally linear vibrating actuator for smart phone slimness has been developed in recent years. One of the most significant parts of horizontal vibrating linear actuator is the guide spring which supports moving part of actuator and enables actuator to vibrate elastically. Various types of leaf springs were designed and analyzed to get the required stiffness with high fatigue life through the stress analysis using commercial structural analysis program, ANSYS. The experiments were performed with prototypes to measure vibration acceleration and life time of leaf spring.

• Korean Journal of Computational Design and Engineering
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• v.16 no.3
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• pp.216-226
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• 2011

Surgeon dentists usually rely on their experiential judgments from patients' oral plaster casts and medical images to determine the positional and directional information of implant fixtures and to perform drilling tasks during dental implant surgical operations. This approach, however, may cause some errors and deteriorate the quality of dental implants. Computer-aided methods have been introduced as supportive tools to alleviate the shortcomings of the conventional approach. In this paper, we present an approach of 3D dental implant simulation which can provide the realistic and immersive experience of dental implant information. The dental implant information is primarily composed of several kinds of 3D mesh models obtained as follows. Firstly, we construct 3D mesh models of jawbones, teeth and nerve curves from the patient's dental images using software $Mimics^{TM}$. Secondly, we construct 3D mesh models of gingival regions from the patient's oral impression using a reverse engineering technique. Thirdly, we select suitable types of implant fixtures from fixture database and determine the positions and directions of the fixtures by using the 3D mesh models and the dental images with software $Simplant^{TM}$. Fourthly, from the geometric and/or directional information of the jawbones, the gingival regions, the teeth and the fixtures, we construct the 3D models of surgical guide stents which are crucial to perform the drilling operations with ease and accuracy. In the application phase, the dental implant information is combined with the tangible interface device to accomplish 3D dental implant simulation. The user can see and touch the 3D models related with dental implant surgery. Furthermore, the user can experience drilling paths to make holes where fixtures are implanted. A preliminary user study shows that the presented approach can be used to provide dental students with good educational contents. With future work, we expect that it can be utilized for clinical studies of dental implant surgery.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.881-886
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• 2007

This study was to develope a vibrotactile display system using windows media player from digital audio signal. WMPlayer10SDK system which was plug-in tool by microsoft windows media player provided its video and audio signal information. The audio signal was tried to be change into vibrotactile display. Audio signal had 4 sections such as 8bit, 16bit, 24bit, and 32bit. Each section was computed its frequency and vibrato scale. And data was transferred to 38400bps network port(COM1) for vibration. Using this system was able to develop the music suit which presented tactile feeling of music beyond sound. Therefore, it may provide cross modal technology for fusion technology of human senses.

• Journal of the Korea Computer Graphics Society
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• v.13 no.2
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• pp.23-29
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• 2007

We are suggesting an authoring tool can be used for prototyping in the augmented reality based product design environment. This tool is for authors without an engineering background to use. Our authoring tool can adjust the properties of visual, sound, and haptic feedback at the same time for more practical prototyping. Also the proposed modulated architecture can be applied flexibly to changes of platforms or hardware. Also user interfaces can be dynamically updated by changing just description files. finally, the suggested authoring methods exploit the advantages of both graphical and tangible user interfaces. Authors can intuitively make adjustments to many parameters using the TUI, and then they can do the same thing precisely using the GVI. The proposed authoring methods can be used for exhibition and entertainment contents using multi-sensory feedback in AR environment. As a future work, qualitative and quantitative usability test will be conducted.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.103-112
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• 2006

In this paper, we propose a PC based immersive virtual environment system with expandability and compatibility in contrary to existing immersive virtual environment(IVE) systems which have been implemented by supercomputer or special computing system. The application based on commercial personal compute may have two major advantage: one is variety of resources, the other is user-friendly interface. This system intends to offer easy contact to IVE system, realistic images, and convenience. Also, the system can handle various virtual reality at real-time and make it easier to interface existing complicated haptic device. Geometric techniques are adopted to calculate and visualize the physical phenomenon to speed up the computing time. The proposed implementation method of PC based immersive virtual environment system is implemented to the example in which user move around inside of and interact with virtual office environment wearing data glove, behavior recognition devices, and HMD.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.29-36
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• 2006

Tactile displays can provide useful information without disturbing others and are particularly useful for people with visual or auditory impairments. They can also complement other displays. In this paper, we present a new vibrotactile display device for wearable, mobile, and ubiquitous computing environments. The proposed vibrotactile device has a $5{\times}5$ array configuration for displaying complex information such as letters, numbers, and haptic patterns as well as simple directional ques and situation awareness alarms. Commercially available coin-type vibration motors are embedded vertically in flexible mounting pads in order to best localize vibrations on the skin. An embedded microprocessor controls the motors sequentially with an advanced tracing mode to increase recognition rate. User studies with the vibrotactile device on the top of the foot show 86.7% recognition rate for alphabet characters after some training. In addition, applying vibrotactile device to driving situation shows 83.9% recognition rate. We also propose some potentially useful application scenarios including Caller Identification for mobile phones and Navigation Aids for GPS systems while driving.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.883-888
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• 2011

Laparoscopic surgery is being used in various surgical fields because it minimizes scarring. Laparoscopic operations require practical hand skills, so surgeons train on animals and via surgery training tool sets. However, these tool sets do not give the surgeon the sensation of touching real organs. A recently developed laparoscope simulator has a high friction force along the translational axis and a high gravity force along the pitch axis, and therefore it does not permit the operator to control his or her hands delecately. In the paper, the friction force along the axes is auumed to depend on the veolcity, and the gravity force on the angle and distance. We develop a compensation model that combines the gravity and friction force models.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.451-456
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• 2009

In this paper, a virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.359-364
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• 2013

In order to use a linear vibration motor for the actuator of a haptic interface, the motor must provide a higher reaction rate and longer service life than typical rotational motors with an eccentric mass. In this paper, we propose a linear vibration motor that is equipped with a voice-coil actuator and permanent-magnet springs. To concentrate the magnetic flux in the actuator, a Halbach-style magnetization pattern is used. Permanent-magnet springs replace mechanical springs to help increase the service life. We use the method of equivalent current sheets and the method of images to analyze and model the proposed vibration motor. These methods are validated using finite element analyses and experiments. A prototype motor is designed and fabricated. Tests with the prototype show the feasibility of the proposed linear vibration motor.