• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2551-2562
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• 2013

Since 2006, an Intelligent Excavation Robot which automatically performs the earth-work without operator has been developed in Korea. The technologies for automatically recognizing the terrain of work environment and detecting the objects such as obstacles or dump trucks are essential for its work quality and safety. In several countries, terrestrial 3D laser scanner and stereo vision camera have been used to model the local area around workspace of the automated construction equipment. However, these attempts have some problems that require high cost to make the sensor system or long processing time to eliminate the noise from 3D model outcome. The objectives of this study are to analyze the advantages of the existing 3D modeling sensors and to examine the applicability for practical use by using Analytic Hierarchical Process(AHP). In this study, 3D modeling quality and accuracy of modeling sensors were tested at the real earth-work environment.

• Wind and Structures
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• v.36 no.4
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• pp.237-247
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• 2023

The emergence of high-rise buildings has necessitated frequent structural health monitoring and maintenance for safety reasons. Wind causes damage and structural changes on tall structures; thus, safe structures should be designed. The pressure developed on tall buildings has been utilized in previous research studies to assess the impacts of wind on structures. The wind tunnel test is a primary research method commonly used to quantify the aerodynamic characteristics of high-rise buildings. Wind pressure is measured by placing pressure sensor taps at different locations on tall buildings, and the collected data are used for analysis. However, sensors may malfunction and produce erroneous data; these data losses make it difficult to analyze aerodynamic properties. Therefore, it is essential to generate missing data relative to the original data obtained from neighboring pressure sensor taps at various intervals. This study proposes a deep learning-based, deep convolutional generative adversarial network (DCGAN) to restore missing data associated with faulty pressure sensors installed on high-rise buildings. The performance of the proposed DCGAN is validated by using a standard imputation model known as the generative adversarial imputation network (GAIN). The average mean-square error (AMSE) and average R-squared (ARSE) are used as performance metrics. The calculated ARSE values by DCGAN on the building model's front, backside, left, and right sides are 0.970, 0.972, 0.984 and 0.978, respectively. The AMSE produced by DCGAN on four sides of the building model is 0.008, 0.010, 0.015 and 0.014. The average standard deviation of the actual measures of the pressure sensors on four sides of the model were 0.1738, 0.1758, 0.2234 and 0.2278. The average standard deviation of the pressure values generated by the proposed DCGAN imputation model was closer to that of the measured actual with values of 0.1736,0.1746,0.2191, and 0.2239 on four sides, respectively. In comparison, the standard deviation of the values predicted by GAIN are 0.1726,0.1735,0.2161, and 0.2209, which is far from actual values. The results demonstrate that DCGAN model fits better for data imputation than the GAIN model with improved accuracy and fewer error rates. Additionally, the DCGAN is utilized to estimate the wind pressure in regions of buildings where no pressure sensor taps are available; the model yielded greater prediction accuracy than GAIN.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1516-1519
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• 2004

A tele-operated robot should be used to maintain and inspect nuclear power plants to reduce the radiation exposure to the human operators. During an overhaul of the nuclear power plants in Korea, a ROV(Remotely Operated Vehicle) may enter a cold-leg connected to the reactor to examine the state of the thermal sleeve and it's position in the safety injection nozzle. To measure the positions of the thermal sleeve or scratches from the video images captured during the examination, the camera parameters should be identified. However, the focal length of the CCD camera could be increased to a close up of the target and the aspect ratio and the center of the image could also be varied with capturing devices. So, it is desired to self-calibrated the intrinsic parameters of the camera and capturing device with the video images captured during the examination. In the video image of the safety injection nozzle, two or more circular grooves around the nozzle are shown as ellipse contours. In this paper, we propose a camera self-calibration method using a single image containing two circular grooves which are the greatest circles of the cylindrical nozzle whose radius and distance are known.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.503-509
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• 2015

In this paper, we designed and tested an ankle joint mechanism for a gait rehabilitation robot. Gait rehabilitation programs are designed to improve the natural leg motion of patients who have lost their walking capabilities by accident or disease. Strengthening the muscles of the lower-limbs and stimulation of the nervous system corresponding to walking helps patients to walk again using gait assistive devices. It is an obvious requirement that the rehabilitation system's motion should be similar to and as natural as the normal gait. However, the system being used for gait rehabilitation does not pay much attention to ankle joints, which play an important role in correct walking as the motion of the ankle should reflect the movement of the center of gravity (COG) of the body. Consequently, we have designed an ankle mechanism that ensures the safety of the patient as well as efficient gait training. Also, even patients with low leg muscle strength are able to operate the ankle joint due to the direct-drive mechanism without a reducer. This safety feature prevents any possible adverse load on the human ankle. The additional degree of freedom for the roll motion achieves a gait pattern which is similar to the normal gait and with a greater degree of comfort.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.634-637
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• 2003

A tele-operated hume concrete pipe laying machine has been developed to solve several problems on safety, quality, productivity, etc. It is required to propose a performance evaluation model and methodology in order to measure productivity, economic feasibility, quality and safety. The primary objective of this study is to propose a model and methodology for the performance evaluation of the developed tele-operated hume concrete pipe laying machine. Furthermore, this study evaluates its performance compared with the existing hume pipe laying work by using data which obtained in field trials. It is anticipated that the proposed model and methodology might be effectively used in analyzing the performance of other automation robots.

• Korean Journal of Construction Engineering and Management
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• v.5 no.1 s.17
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• pp.157-167
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• 2004

In developing an automated construction system, it is essential to propose a performance evaluation model and methodology, which can measure productivity, quality, safety and economic feasibility in order to verify its superiority. Recently, a tele-operated hume concrete pipe laying machine has been developed to solve several problems related to safety, quality, productivity in conventional method. The primary objective of this study is to propose a model and methodology for the performance evaluation of the developed tele-operated hume concrete pipe laying machine. Furthermore, this study evaluates the automation machine's performance compared with the existing hume pipe laying work by using data which obtained in many field trials. It is anticipated that the proposed model and methodology might be effectively used in analyzing the performance of other automation robots.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7627-7632
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• 2015

Background: The present study was conducted to evaluate the technical feasibility, safety and adequacy of surgical margins with salvage transoral robotic surgery (TORS) for recurrent or residual head and neck squamous cell carcinoma patients. Materials and Methods: Thirty patients who underwent salvage TORS using the 'DaVinci' robot were enrolled in the study and data related to their surgical time, complications and functional outcome were recorded. Results: The feasibility of salvage TORS in our study was observed to be 100%. Positive margins were encountered in only 6.7% of patients. Mean blood loss was 23.3 ml with no patient requiring blood transfusion. Postoperative complications in the form of primary haemorrhage requiring active surgical intervention occurred in 13.3%. Oral feeding could be started as early as the 3rd postoperative day in a few patients, with nasogastric tubes being removed on the 12th postoperative day. Long term gastrostomy tube dependency was seen in 10% cases. Median survival of patients was 19 months. Conclusions: Salvage TORS is a safe, effective and feasible option in the management of treatment failure cases. It offers an alternative surgical approach with unexpected benefits in terms of tracheostomy tube use, Ryle's tube and gastrostomy dependence.

• Health Policy and Management
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• v.25 no.2
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• pp.67-70
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• 2015

To establish an appropriate policy for robotic surgery in Korea, the National Evidence-based Collaborating Agency (NECA) and the Korean Society of Health Policy and Administration held a round-table conference (RTC) to gather opinions through a comprehensive discussion of scientific information in gastric cancer. The NECA RTC is a public discussion forum wherein experts from diverse fields and members of the lay public conduct in-depth discussions on a selected social issue in the health and medical field. For this study, representatives from the medical field, patient groups, industry, the press, and policy makers participated in a discussion focused on the medical and scientific evidence for the use of robotic surgery in gastric cancer. According to the RTC results, robotic surgery showed more favorable results in safety and efficacy than open surgery and it is similar to laparoscopy. When the cost-effectiveness of robotic surgery and laparoscopy is compared, robotic surgery costs are higher but there was no difference between the two of them in terms of effectiveness (pain, quality of life, complications, etc.). In order to resolve the high cost issue of the robotic surgery, a proper policy should be implemented to facilitate the development of a cost-effective model of the robotic surgery equipment. The higher cost of robotic surgery require more evidence of its safety and efficacy as well as the cost-effectiveness issues of this method. Discussions on the national insurance coverage of robotic surgery seems to be necessary in the near future.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.187-196
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• 2014

This paper suggests linearity enhancement algorithm to Ensure safety of Mobile Walker on Slope. Mobile Walker happens to get off track due to external forces from Walker's weight and the degree of the slope while slope driving. In order to compensate this, this research used the controller that estimates the external forces according to the slope of road surface and adjusts it to the motor output. Also, through comparisons between targeted rotational angular velocity which the user inputs and its velocity of the robot, algorithm was applied which applies a weight to each shaft. As a result of applying the proposed correction controller, it diverges in case of non-compensation experiments that deviates when moving, but it case of applying the ramp calibration algorithm, the deviation distance at max was within 10cm that it keeps safe driving, and change rate of deviation distance was also stabilized after 1m where no more changes occurred.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.169-175
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• 2014

In this study, it is intended to provide a slip detector is an important function in the research on the slip control can be addressed uncontrollably path withdrawal might during driving of the power wheelchair, slip phenomenon occurs. By detecting and electric wheelchairs, the state of the motor during running, the detection of the slip, slip detection information calculated using an encoder that is connected to the left and right motor with six-axis IMU sensor for the electric wheelchair using an algorithm to calculate the slip ratio. Slip rate calculated in this way is used as control variable for improving the safety of the electric wheelchair. It was confirmed from the slip phenomenon of the path the proposed experiments slim detector proposed in this study. The maximum slip ratio detection zone during the experiment, can occur during turning of the electric wheelchair has been confirmed.