• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.109-115
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• 2011

In this research, three topics were studied for the elderly. The first was the elderly's error characteristics for tracing task and the second was for depth perception. The characteristics were compared with the young's. Twenty two old people and twenty two young people participated in the tracing experiment, respectively. In the depth perception experiment, twenty three old people and twenty two young people participated. A depth perception apparatus and a tracing one were used in the experiment. In the depth perception error, a significant difference was not detected on gender. However significant differences were detected with age and viewing distance. In the tracing error, significant difference was detected with age, also. The third experiment was push-button operation and fifteen old people participated in the experiment. As the result, operation time error was increased with the button size and the moving distance. The result of this study will be able to be considered in its user interface design to reduce the elderly's error while using a product.

• Journal of Korean Institute of Industrial Engineers
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• v.16 no.2
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• pp.99-107
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• 1990

Many accidents related to robot operation occur during the robot teaching process. This paper deals with recommendations for the teach pendant design parameters to enhance safety and performances in human-robot interactions. In order to investigate the optimum location and the size of the emergency stop button on the teach pendant, an experiment was conducted with a simulated teach pendant which can accomodate four different locations and three sizes of the button. Under a simulated emergency condition, the reach time to the emergency stop button was measured at random combination of the location and the size of button. The reach time was significantly affected by the location and the size of the emergency stop button. The fastest average reach time was attained with 1.5 inch-diameter button on the upper center of the teach pendant.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.115-122
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• 2011

Background: The intramural coronary artery has been known as a risk factor for early death after an arterial switch operation (ASO). We reviewed the morphological characteristics and evaluated the early and mid-term results of ASO for patients with an intramural coronary artery. Materials and Methods: From March 1994 to September 15th 2010, 158 patients underwent ASO at Dong-A and Pusan National University Hospitals for repair of transposition of the great arteries and double outlet right ventricle. Among these patients, 14 patients (8.9%) had an intramural coronary artery. Mean age at operation was $13.4{\pm}10.2$ days (4 to 39 days) and mean body weight was $3.48{\pm}0.33$ kg (2.88 to 3.88 kg). All patients except one were male. Eight patients had TGA/IVS and 4 patients had an aortic arch anomaly. Two patients (14.3%) had side-by-side great artery relation, of whom one had an intramural right coronary artery and the other had an intramural left anterior descending coronary artery. Twelve patients had anterior-posterior relation, all of whom had an intramural left coronary artery (LCA). The aortocoronary flap technique was used in coronary transfer in 8 patients, of whom one patient required a switch to the individual coronary button technique 2 days after operation because of myocardial ischemia. An individual coronary button implantation technique was adopted in 6, of whom 2 patients required left subclavian artery free graft to LCA during the same operation due to LCA injury during coronary button mobilization and LCA torsion. Results: There was 1 operative death (7.1%), which occurred in the first patient in our series. This patient underwent an aortocoronary flap procedure for coronary transfer combining aortic arch repair. Overall operative mortality for 144 patients without an intramural coronary artery was 13.2% (19/144). There was no statistical difference in operative mortality between the patients with and without an intramural coronary artery (p>0.1). There was no late death. The mean follow-up duration was $52.1{\pm}43.0$ months (0.5 to 132 months). One patient who had a subclavian artery free graft required LCA stenting 6.5 years after surgery for LCA anastomotic site stenosis. No other surviving patient needed any intervention for coronary problems. All patients had normal ventricular function at latest echocardiography and were in NYHA class 1. Conclusion: The arterial switch operation in Transposition of Great Arteries or Double Outlet Right Ventricle patients with intramural coronary can be performed with low mortality; however, there is a high incidence of intraoperative or postoperative coronary problems, which can be managed with conversion to the individual coronary button technique and a bypass procedure using a left subclavian free graft. Both aortocoronary flap and individual coronary button implantation techniques for coronary transfer have excellent mid-term results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.53-66
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• 2017

In order to improve traffic flow and vehicular safety, installation of roundabouts is encouraging recently. Roundabouts are generally installed at which traffic flow and pedestrian flow is relatively low intersections. Roundabouts reduce vehicle speed, minimize vehicle weaving, and reduce critical conflict points. For these reasons, roundabouts are generally operated unprotected pedestrian crosswalk, thus a shortcoming for pedestrian safety always exists at roundabouts. The purpose of this study is developing a dynamic signal metering algorithm for traffic and pedestrian at four-way-approach with two-lane roundabouts in which three different operation algorithms(fixed-time pedestrian, vehicle signal metering, and vehicle and pedestrian signal metering) are suggested and its performance is tested by using VISSIM. The results of the fixed pedestrian signal operation show that there is a big average delay increase in general and that increases up to 51.4 seconds/vehicle(42.5%) when the total number of approaching vehicle is 3,800 vehicle/hour. However, the results of the simultaneous dynamic signal metering operation for the vehicle and pedestrian crossing with push button show that there is a substantial average delay reduction up to 40.6 seconds/vehicle(42.7%) when the total number of approaching vehicle is 3,000 vehicle/hour.

• Journal of Chest Surgery
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• v.55 no.3
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• pp.243-245
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• 2022

True aneurysms of the coronary artery after aortic root replacement in Marfan syndrome patients are very rare. An anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva adds complexity during aortic root surgery. We present a case of a 37-year-old male patient with Marfan syndrome who had an RCA anomaly and a 4.5-cm true aneurysm of the common coronary button 14 years after a previous Bentall procedure. A redo Bentall operation and hemi-arch replacement were successfully performed. The anomalous origin of the RCA from the left sinus of Valsalva was safely divided and anastomosed as separate coronary buttons to the prosthetic composite valve graft. To prevent coronary button aneurysms after aortic root surgery in Marfan patients, the coronary buttons and the corresponding side holes on the prosthetic graft must be reduced to the maximum possible extent.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.356-364
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• 2002

Background: This study was undertaken to investigate the outcome of composite graft aortic root replacement using coronary button reimplantation technique for the treatment of aneurysms of the ascending aorta involving the aortic root. Material and Method: Between April 1995 and September 2001, 54 patients having aortic root replacement with a composite valve graft using direct coronary button reimplantation were reviewed retrospectively. Left ventricular dysfunction was present in 14 patients(25.9%), aortic regurgitation in 48(89%), and Marfan's syndrome in 17(31.5%). The indications for operation were annuloaortic ectasia in 29 patients(53.7%), aortic dissection in 11(20.4%), aneurysms of the ascending aorta involving aortic root in 12(22.2%), and aortitis in 2(3.7%). Six patients(11.1%) had previous cardiac or ascending aortic operations. Concomitant procedures were arch replacement in 21 patients(38.9%), coronary artery bypass graft in 7(13%), mitral valve repair or replacement in 4(7.4%), and others in 6. The mean time of circulatory arrest, total bypass, and aortic crossclamp were 18 $\pm$ 9 minutes, 177 $\pm$ 42 minutes, and 127 $\pm$ 31 minutes, respectively. Result: There was 1 early death(1.9%). Mean follow-up was 24.6$\pm$ 19.5 months. There were two late deaths(3.8%) including one death due to the traumatic cerebral hemorrhage. The Kaplan-Meier survival rate was 98.0 $\pm$ 2.0% and 93.1 $\pm$ 5.1% at 1 and 6 years, respectively. Two patients required reoperation owing to a false aneurysm at the root anastomosis site and a malfunction of prosthetic aortic valve(3.8%). Staged operation for dissection of the remaining thoracoabdominal aorta was performed in 1 patient. The freedom rate from reoperation was 97.8 $\pm$ 2.0% and 65.3 $\pm$ 26.7% at 1 and 6 years, respectively.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.181-186
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• 2017

In recent years, robots have been actively used for children's creativity learning and play, but most robots have a stereotyped form and have a high dependency on the program, making it difficult to learn creativity and play. In order to compensate for these drawbacks, We have created a robot that can easily and reliably combine each other. The robot can memorize the desired operation and execute the memorized operation by using one button. Also, in case multiple modules are combined, pressing the button once on any module makes it possible to easily adjust the operation of all the combined modules. In order to verify the actual operation, two, three, and five modules are combined to demonstrate the usefulness of the proposed structure and algorithm by implementing a gobbling motion and a walking robot. It is required to study intelligent modular robots that can control over the Internet by supplementing the wireless connection method.

• Journal of Chest Surgery
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• v.27 no.2
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• pp.153-156
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• 1994

Bentall`s operation for repair of annuloaortic ectasia has been associated with postoperative bleeding and with false aneurysm of the anastomotic site between the coronary orifice and composite graft.Among 5 cases, 2 cases have been operated direct anastomosis between coronary artery and vascular graft.Remained 3 cases have been operated with doughnutlike Teflon felt buttress.The technique of sandwiching the freed button of aortic wall bearing the coronary artery ostium between an outer Teflon felt doughnutlike buttress and the inner composite graft provides a leak-proof anastomosis.We experienced one case reoperation for bleeding at coronary anastomotic site above method.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.129-137
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• 2019

Ubiquitous computing technology is emerging as information technology advances. In line with this, a number of studies are being carried out to increase device miniaturization and user convenience. Some of the proposed devices are user-friendly and uncomfortable with hand-held operation. To address these inconveniences, this paper proposed a virtual button that could be used in watching television. When watching a video on television, a camera is installed at the top of the TV, using the fact that the user watches the video from the front, so that the camera takes a picture of the top of the head. Extract the background and hand area separately from the filmed image, extract the outline to the extracted hand area, and detect the tip point of the finger. Detection of the end point of the finger produces a virtual button interface at the top of the image being filmed in front, and the button activates when the end point of the detected finger becomes a pointer and is located inside the button.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.121-128
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• 2009

This study has proposed the signal operating system to use both semi-actuated signal control and pedestrian push-button as a way to make up for the problems of 3 leg intersections which are operated inefficiently in the signal operation, one of the methods of traffic operations. In case of the semi-actuated signal control, it can reduce delay inside the intersection by serving to uncongested traffic on the main road where there is not much traffic volume on the secondary road and push-button signal can reduce unnecessary waiting time it could happen to vehicles by operating it though there is no pedestrian. Quantitative analysis was tried regarding the average delay reduction per vehicle using VISSIM, microscopic simulation program regarding how much effect it has compared with the existing signal control system and semi-actuated signal control system when the above two advantages are collected. The field test was performed for one three-leg intersection of Incheon. According to respectively signal control method pedestrian traffic changed and executed a sensitivity analysis. The result which compares the average delay time per a vehicle of scenarios, the signal control method of using the pedestrian push-button system in comparison with the fixed signal control method showed to decrease effect of a minimum 3.7 second (10%), a maximum 5.8 second (16%). When the pedestrian traffic volume was 20% or less of the measurement traffic volume, The signal control method of using the pedestrian push-button system appeared to be more efficient the semi-actuated signal control with object intersection.