• Korea Journal of Hospital Management
• /
• v.27 no.2
• /
• pp.16-33
• /
• 2022

Purposes: Prompt evaluation of routes and contact tracing are very important for epidemiological investigations of coronavirus disease 2019 (COVID-19). To ensure better adoption of contact tracing apps, it is necessary to understand users' expectations, preferences, and concerns. This study aimed to identify main reasons why people use the apps, appropriate services, and basis for voluntary app services that can improve app participation rates and data sharing. Methodology/Approach: This study conducted an online survey from November 11 to December 6, 2020, and received a total of 1,048 survey responses. This study analyzed the questionnaire survey findings of 883 respondents in areas with many confirmed cases of COVID-19. This study used a multiple regression analysis. Findings: Respondents who had experience of using related apps showed a high intention to use contact-tracing apps. Participants wished for the contact tracking apps to be provided by the government or public health centers (74%) and preferred free apps (93.88%). The factors affecting the participants' intention to use these apps were their preventive value, performance expectancy, perceived risk, facilitative ability, and effort expectancy. The results highlighted the need to ensure voluntary participation to address participants' concerns regarding privacy protection and personal information exposure. Practical Implications: The results can be used to accurately identify user needs and appropriate services and thereby improve the development of contact tracking apps. The findings provide the basis for voluntary app that can enhance app participation rates and data sharing. The results will also serve as the basis for developing trusted apps that can facilitate epidemiological investigations.

• Journal of Welding and Joining
• /
• v.32 no.6
• /
• pp.35-40
• /
• 2014

The contact tip for gas metal arc welding has important functions to transmit the welding current to the wire and to guide the wire to molten pool. If the contact tip is damaged, it is a cause of lowering the welding productivity due to removal of welding defects and replacement of contact tip. In case of the use of a contact tip for a long time the arc is unstable because the processed hole in the contact tip center is larger, and the variation of aiming position of the welding wire causes a seam tracking error. In this study, gas metal arc welding experiments using contact tip of three different materials were performed. The contact tips with Cu-P, Cu-Cr, and Cu-ODS were used at the experiments, and the welding characteristics by each contact tip were evaluated. After welding contact tip appearance, welding spatter adhesion amount of the nozzle, and weld bead appearance were evaluated. The welding current and welding voltage were measured to verify arc stability during arc welding.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.11
• /
• pp.1001-1007
• /
• 2003

The silicone fluids have been generally used as processing agent in silicone rubber(SIR) compounding. The addition of hydroxy silicone (HS) fluids to SIR for insulator housing material is required to meet the good electrical performance and the good processability. In this study, SIR with HS fluids was evaluated to investigate how the kinds of them affect insulation properties. The contact angle of the virgin sample of 40-HS SIR was low and its recovery rate was also slow. The recovery rate of 50-HS SIR was the highest being decreased with the viscosity increase of HS fluids. The tracking resistances and the corona aging resistance of 70-HS SIR and 1,040-HS SIR were excellent Tracking resistance depended largely on heat resistance of silicone fluids. But arc resistance didn't depend merely on the kind of silicone fluids.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.7
• /
• pp.681-687
• /
• 2010

In this paper, an implementation of force control for a slave mobile robot in tele-operation environment is presented. A mobile robot is built to have a force control capability with a force sensor and tested for force tracking control performances. Both position and contact force are regulated by a PID based hybrid control method and the impedance force control method. To minimize accumulated errors due to the adaptive impedance force control method, the novel force control method with a weighted function is proposed. Experimental studies of regulating contact forces for different control algorithms are tested and their performances are compared.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.6
• /
• pp.389-396
• /
• 2016

The sealing robot must be able to calculate the slope of a contact surface for complete adherence of the sealing on different concrete shapes. After the slope is obtained, the robot will track on the surface of the concrete, but this process contains an error in the actual purpose of the force command. The reason this a phenomenon occurs, the non-linearity of the contact surface and the end-effector, is due to parasitic coupling. Errors like make it difficult to measure accurately the respective factors. Therefore, it is regarded as a disturbance that occurs when it follows the work surface it. In this paper, we selected the friction coefficient of the surface as a control factor and designed a compensator to reduce effects of disturbance. Finally, in view of the non-linearity of the end-effector of a robot to contact surfaces directly, we propose a robust force tracking controller in the finite range for managing disturbances that occur during the sealing.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2007.11a
• /
• pp.205-210
• /
• 2007

This study on the prevention of electric fire. Generally the electric fire is caused by break or disconnection of the power line, short circuit and poor contact, arcing fault ect. In these causes, this paper is studied on the detection of poor contact and arcing fault. The arcing fault is caused by poor contact mainly. The arcing fault can occurs a electric fire by interaction of flammable gas and materials and it can be caused of tracking and carbonization. These phenomenons is also caused of electric fire. Therefore this paper is studied on the detection of arcing fault and poor contact.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10a
• /
• pp.8-11
• /
• 1996

In impedance control for contact force tracking it is well known that the reference trajectory of the robot is calculated from known environment stiffness. The accuracy of estimating the environment stiffness determines the performance of the resulting force tracking. Here we present a simple technique, called the trajectory modification technique(TMT), of determining the reference trajectory under the condition that the environment stiffness is unknown. Computer simulation studies have shown that force tracking using the proposed technique is excellent for unknown environment with time varying stiffness.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2502-2507
• /
• 2003

In this paper, a crack sealing robot is developed. The crack sealing robot is built to detect, track, and seal the crack on the pavement. The sealing robot is required to brush all dirt in the crack out for preparing a better sealing job. Camera calibration has been done to get accurate crack position. In order to perform a cleaning job, the explicit force control method is used to regulate a specified desired force in order to maintain constant contact with the ground. Experimental studies of force tracking control are conducted under unknown environment stiffness and location. Crack tracking control is performed. Force tracking results are excellent and the robot finds and tracks the crack very well.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.8
• /
• pp.789-794
• /
• 2014

This paper presents some real performance of two typical bilateral teleoperation benchmark tasks: peg-in-hole and surface tracking tasks. The tasks are performed by an energy-bounding algorithm in the master control and position-based impedance algorithm in the slave control. Performance is analyzed for the position-force tracking capabilities from free space motion to surface contacting motion. In addition, preliminary user performance is evaluated by measuring the completion time and maximum/average contact forces. The quality of the measured performance is also compared with that of other existing approaches.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.14 no.1
• /
• pp.17-25
• /
• 2014

This paper presents the formulation of an impedance controller for regulating the contact force with the environment. To achieve an accurate force tracking control, uncertainties in both robot dynamics and the environment require to be addressed. As part of the framework of the proposed force tracking formulation, a neural network is introduced at the desired trajectory to compensate for all uncertainties in an on-line manner. Compensation at the input trajectory leads to a remarkable structural advantage in that no modifications of the internal force controllers are required. Minimizing the objective function of the training signal for a neural network satisfies the desired force tracking performance. A neural network actually compensates for uncertainties at the input trajectory level in an on-line fashion. Simulation results confirm the position and force tracking abilities of a robot manipulator.