• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1559-1564
• /
• 2003

In this paper, a control method is presented to improve performance of haptic display on a passive haptic device equipped with passive actuators. In displaying a virtual wall with the passive haptic device, an unstable behavior occurs with excessive actions of brakes due to the time delay mainly arising from the update rate of the virtual environment and force approximation originated from the characteristics of the passive actuators. The previous T.D.P.C. (Time Domain Passivity Control) method was not suitable for the passive haptic device, since a programmable damper used in the previously introduced T.D.P.C. method easily leads to undesirable behaviors. A new passivity control method is evaluated with considering characteristics of the passive device. First, we propose a control method which is designed under the analysis of the passive FME (Force Manipulability Ellipsoid). And then a passivity control scheme is applied to the proposed control method. Various experiments have been conducted to verify the proposed method with a 2-link mechanism.

• The Journal of Korea Robotics Society
• /
• v.8 no.3
• /
• pp.186-196
• /
• 2013

Since its introduction (e.g., [4, 6]), virtual coupling technique has been de facto way to connect a haptic device with a virtual proxy for haptic rendering and control. However, because of the single dependence on spring-damper feedback action, this virtual coupling suffers from the degraded transparency particularly during contact tasks when large device/proxy-forces are involved. In this paper, we propose a novel virtual coupling technique, which, by utilizing passive decomposition, reduces device-proxy position deviation even during the contact tasks while also scaling down (or up) the apparent inertia of the coordinated device-proxy. By doing so, we can significantly improve transparency between multiple degree of freedom (possibly nonlinear) haptic device and virtual proxy. In other to use passive decomposition, disturbance observer of [3] is adopted to estimate human force with some dead-zone modification to avoid "winding-up" force estimation in the presence of device torque saturation. Some preliminary experimental results are also given to illustrate efficacy of the proposed technique.

• Journal of the Korea Safety Management & Science
• /
• v.20 no.2
• /
• pp.1-8
• /
• 2018

This study aims to provide a real-time information to the driver by effectively operating the advanced safety device attached to the freight vehicle, thereby minimizing insecure behavior of the driver such as speeding, rapid acceleration, sudden braking, And improve driving habits to prevent accidents and save energy. Advanced safety equipment is a device that warns the driver that the vehicle leaves the driving lane regardless of the intention of the driver and reduces the risk of traffic accidents by mitigating or avoiding collision by detecting a frontal collision during driving.The main contents of this report are as follows: In case of installing a warning device on a lane departing vehicle (excluding a light vehicle) and a lorry or special vehicle with a total weight exceeding 3.5 tonnes, the driver must continue to operate unless the driver releases the function.In addition, when the automatic emergency braking system is installed, the structure should be such that the braking device is operated automatically after warning the driver when the risk of collision with the running or stopped vehicle in the same direction is detected in front of the driving lane.

• Korean Journal of Computational Design and Engineering
• /
• v.19 no.2
• /
• pp.191-201
• /
• 2014

A 3D CAD system that can be used on a smart device is proposed. Smart devices are now a part of everyday life and also are widely being used in various industry domains. The proposed 3D CAD system would allow modeling in a rapid and intuitive manner on a smart device when an engineer makes a 3D model of a product while moving in an engineering site. There are several obstacles to develop a 3D CAD system on a smart device such as low computing power and the small screen of smart devices, imprecise touch inputs, and transfer problems of created 3D models between PCs and smart devices. The author discusses the system design of a 3D CAD system on a smart device. The selection of the modeling operations, the assignment of touch gestures to these operations, and the construction of a geometric kernel for creating both meshes and a procedural CAD model are introduced. The proposed CAD system has been implemented for validation by user tests and to demonstrate case studies using test examples. Using the proposed system, it is possible to produce a 3D editable model swiftly and simply in a smart device environment to reduce design time of engineers.

• The Journal of Information Systems
• /
• v.25 no.2
• /
• pp.27-50
• /
• 2016

Purpose The purpose of this study is to examine the effect of the acceptance intention towards healthcare wearable device in Korea. Specifically, this study attempted to identify the relationships among the acceptance intention towards healthcare wearable device, technical characteristics and user's personal characteristic based on UTAUT(Unified Theory of Acceptance and Use of Technology) model. Design/methodology/approach For this purpose of research, we conducted against consumers who use the wearable devices and we collected data from 219 wearable device users. The analyses were conducted using SPSS and AMOS19.0 which is powerful structural equation modeling (SEM) software. Findings The main findings are as followed; First, functional diversity, wearability, trend sensitivity and health perception are significantly related to performance expectancy, while visual aesthetic and enjoyment are not significantly related. Second, performance expectancy and effort expectancy are significantly related to acceptance intention towards healthcare wearable device. Third, effort expectancy is significantly related to performance expectancy.

• Proceedings of the KIEE Conference
• /
• 1999.11d
• /
• pp.997-999
• /
• 1999

We fabricated white light-emitting organic electroluminescent device which have a mixed single emitting layer containing poly(N-vinylcarbazole)[PVK], tris(8-hydroxyquinoline)aluminum[Alq3] and poly(3-hexylthiophene)[P3HT] and investigated the emission properties of it. We expect to obtain a blue light from PVK, green light from Alq3 and red light from P3HT The fabricated device emits white light over 18V with slight orange light. We think that the energy transfer in a mixed layer occurred from PVK to $Alq_3$ and P3HT resulted in decreasing the blue light intensity from PVK. With mixing of N, N'-diphenyl-N, N'-(3-methylphenyl)-[1,1'-biphenyl]-4, 4'-diamine[TPD], hole transport material, to the emitting layer, the luminance intensity of device was increased 50 times than that of the device which not contain TPD. We find that the efficiency of the white light electroluminescent device can be improved by injecting electron more effectively and blue light need to improve the color purity of white light.

• Journal of the Korean Society for Railway
• /
• v.13 no.6
• /
• pp.541-545
• /
• 2010

Because contemporary rolling stock system is complex and highly advanced, and it builds mutual interface, it is necessary to manage maintenance of rolling stock systematically. This study present a case, which shows how to adopt and apply RTD(Remote Transmission Device) integrated to train information collection device. After the train service is complete and the train enters the main subway station, various kinds of information collected from TCMS(Train Control Monitoring System) is transmitted to train depot information collection device through RTD. This study suggests that RTD integrated to train information collection device helps build an effective rolling stock maintenance system by improving reliability of data transmission and cutting maintenance costs.

• Korean Journal of Materials Research
• /
• v.25 no.10
• /
• pp.523-530
• /
• 2015

Electricity generation through fossil fuels has caused environmental pollution. To solve this problem, research on new renewable energy (solar, wind, geothermal heat, etc.) to replace fossil fuels is in progress. These devices are able to consistently generate power. However, they have many drawbacks, such as high installation costs and limitations in possible set-up environments. Thus, piezoelectric harvesting technology, which is able to overcome the limitations of existing energy technologies, is actively being studied. Piezoelectric harvesting technology uses the piezoelectric effect which occurs in crystals that generate voltage when stress is applied. Therefore, it has advantages such as a wider installation base and lower technological cost. In this study, a piezoelectric energy harvesting device based on constant wave motion was investigated. This device can regenerate electricity in a constant turbulent flow in the middle of the sea. The components of the device are circuitry, a steel bar, an bimorph piezoelectric element and buoyancy elements. In addition, a multiphysical analysis coupled with the structure and piezoelectric elements was conducted to estimate the performance of the device. With this piezoelectric energy harvesting device, the displacement and electric power were analyzed.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.18 no.4
• /
• pp.409-414
• /
• 2015

M125 booster is one of the reliable S&A device(safety and arming device) to determine the arming distance of fuze for gun ammunitions from 90 mm to 8 inch in diameter. And it is also well known that the arming distance of M125 booster is determined by the multiplication value of the gun tube property(traveled distance per turn of projectile) and the S&A device property(number of turns to arm), not by the projectile muzzle velocity. We have tried and succeeded in executing a proper analysis on M125 booster to figure out its characteristic constant of arming distance by considering only the gun tube properties and the S&A device properties. More detailed arming distance will be analyzed in the future by considering dynamic characteristics on all elements in the S&A device with vector analysis.

• Journal of Satellite, Information and Communications
• /
• v.6 no.2
• /
• pp.10-14
• /
• 2011

This paper suggests the method to calculate radiation limit of ISM(Industrial Scientific Medical) equipment in order to protect radio device in the situation that ISM equipment and radio device are operated in near distance. The factor for correction and protection ratio which is need for protecting radio device were considered to calculate radiation limit of ISM equipment. Also, the scenario which is required to limit radiation power of ISM equipment was referred and the S/W for calculation of radiation limit was developed by using GUI(Graphical User Interface) on Matlab. The suggested method for calculation of radiation limit of ISM equipment will be used to protect radio device from ISM equipment.