• Safety and Health at Work
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• v.1 no.1
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• pp.43-50
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• 2010

Objectives: The objective of this study was to investigate the effect of chain installation condition on stress distribution that could eventually cause disastrous failure from sudden deformation and geometric rupture. Methods: Fractographic method used for the failed chain indicates that over-stress was considered as the root cause of failure. 3D modeling and finite element analysis for the chain, used in a crane hook, were performed with a three-dimensional interactive application program, CATIA, commercial finite element analysis and computational fluid dynamic software, ANSYS. Results: The results showed that the state of stress was changed depending on the initial position of the chain that was installed in the hook. Especially, the magnitude of the stress was strongly affected by the bending forces, which are 2.5 times greater (under the simulation condition currently investigated) than that from the plain tensile load. Also, it was noted that the change of load state is strongly related to the failure of parts. The chain can hold an ultimate load of about 8 tons with only the tensile load acting on it. Conclusion: The conclusions of this research clearly showed that a reduction of the loss from similar incidents can be achieved when an operator properly handles the installation of the chain.

• Safety and Health at Work
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• v.10 no.2
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• pp.213-218
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• 2019

Background: Motorcycles are one of the important members of commercial transportation because of the convenient use during congested traffic conditions and the ease of parking in narrow streets. This study investigates the characteristics of crashes and traffic signal violations caused by motorcycle couriers. Methods: From the national compensation data, this study analyzed the traffic crashes caused by 671 motorcycle couriers. Results: Among 671 injured couriers, 50.6% were aged less than 40 years, 49.2% run in a small business of <5 employees, and 47.2% had work experience of <6 months. Motorcycle crashes occurred mainly due to "rider overturned alone" (67.5%), in the daytime (73.5%), or on cloudy or clear days (77.2%). However, the violation rate caused by motorcycle couriers was high in couriers in a small business of <5 employees (13.9%), with work experience of <6 months (13.9%), on cloudy or clear days (12.4%), on an intersection (29.8%), in the type of "crash with a vehicle" (31.2%), or in a death accident (35.7%) Conclusion: The findings of this study can be used as a baseline in devising policies for preventing crashes of motorcycle couriers.

• Archives of Craniofacial Surgery
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• v.21 no.6
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• pp.384-386
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• 2020

This report describes osteotomy and iliac bone graft for malunion caused by failed mandibular fracture reduction. A 27-year-old man was referred 3 months after a motor vehicle accident. At another hospital, two operations had been performed for symphyseal fracture using two resorbable plates. Malocclusion was noted, and panoramic radiography and computed tomography revealed a misaligned dental arch, with a 9.37-mm gap between the central and the lateral incisor of the left mandible. A wafer was made from the patient's dental model, and a maxillary arch bar was applied. Through a lower gingivolabial incision, osteotomy was performed between the malunited symphyseal fracture segments. Both segments were reduced to their original position using the wafer and fixed with titanium miniplates via intermaxillary fixation (IMF). The intersegmental gap was filled with cancellous bone from the iliac crest. The gingival defect was covered with a mucosal transposition flap from the gingivolabial sulcus. IMF and the wafer were maintained for 5 and 9 weeks, respectively. At postoperative week 13, the screws were removed from the mandible and satisfactory occlusion was noted. His mouth opening improved from 2.5 to 3 finger breadths (40 mm). This case demonstrates the need for sufficient IMF when using resorbable plates.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.284-287
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• 2021

We report a case of delayed chest wall reconstruction after thoracotomy. A 53-yearold female, a victim of a motor vehicle accident, presented with bilateral multiple rib fractures with flail motion and multiple extrathoracic injuries. Whole-body computed tomography revealed multiple fractures of the bilateral ribs, clavicle, and scapula, and bilateral hemopneumothorax with severe lung contusions. Active hemorrhage was also found in the anterior pelvis, which was treated by angioembolization. The patient was transferred to the surgical intensive care unit for follow-up. We planned to perform surgical stabilization of rib fractures (SSRF) because her lung condition did not seem favorable for general anesthesia. Within a few hours, however, massive hemorrhage (presumably due to coagulopathy) drained through the thoracic drainage catheter. We performed an exploratory thoracotomy in the operating room. We initially planned to perform exploratory thoracotomy and "on the way out" SSRF. In the operating room, the hemorrhage was controlled; however, her condition deteriorated and SSRF could not be completed. SSRF was completed after about a month owing to other medical conditions, and the patient was weaned successfully.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.199-200
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• 2021

최근 어린이 보호구역 내에서의 운전자의 부주의로 사망 혹은 상해 사고를 일으킨 가해자를 가중 처벌하는 내용의 '민식이법'이 발의됨에 따라 많은 운전자들이 보호구역을 주행할 때 많은 부담감을 느끼며, 이에 대한 운전자의 부담감과 사고 피해를 최소화할 수 있는 시스템이 필요하다. 본 논문에서는 OpenCV 영상인식기술과 OCR 문자인식기술인 Tesseract를 이용해 노약자 보호구역 표지판을 인식하여 법정 제한속도를 준수하며 갑작스러운 장애물 등장 시 급정거하여 사고피해를 최소화하고, 또한, 사용자에게 알람 메시지를 전송하는 시스템을 제안한다.

• Journal of Ocean Engineering and Technology
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• v.37 no.3
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• pp.99-110
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• 2023

When a fire accident accompanied by an explosion occurs, the surrounding firewalls are affected by impact and thermal loads. Damaged firewalls due to accidental loads may not fully perform their essential function. Therefore, this paper proposes an advanced methodology for evaluating the fire resistance performance of firewalls damaged by explosions. The fragments were assumed to be scattered, and fire occurred as a vehicle exploded in a large compartment of a roll-on/roll-off (RO-RO) vessel. The impact velocity of the fragments was calculated based on the TNT equivalent mass corresponding to the explosion pressure. Damage and thermal-structural response analyses of the firewall were performed using Ansys LS-DYNA code. The fire resistance reduction was analyzed in terms of the temperature difference between fire-exposed and unexposed surfaces, temperature increase rate, and reference temperature arrival time. The degree of damage and the fire resistance performance of the firewalls varied significantly depending on impact loads. When naval ships and RO-RO vessels that carry various explosive substances are designed, it is reasonable to predict that the fire resistance performance will be degraded according to the explosion characteristics of the cargo.

• Journal of Arbitration Studies
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• v.31 no.4
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• pp.119-136
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• 2021

Due to the restriction of movement caused by the Corona epidemic and the expansion of the "big face" through human distance, the "unmanned system" based on artificial intelligence and the Internet of Things has been widely used in modern life. "Self-driving," one of the transportation systems based on artificial technology, has taken the initiative in the transportation system as the spread of Corona has begun. Self-driving technology eliminates unnecessary contact and saves time and manpower, which can significantly impact current and future transportation. Accidents may occur, however, due to the performance of self-driving technology during transportation albeit the U.S. allows ordinary people to drive automatically through experimental operations, and the product liability law will resolve the dispute. Self-driving has become popular in the U.S. after the experimental stage, and in the event of a self-driving accident, product liability should be applied to protect drivers from complicated self-driving disputes. The purpose of this paper is to investigate whether disputes caused by defects in ordinary cars can be resolved through arbitration through U.S. precedents and to investigate whether disputes caused by defects in autonomous cars can be arbitrated.

• Smart Media Journal
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• v.12 no.11
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• pp.95-102
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• 2023

Road accidents not only caused loss of human lives but also costed 3% of gross domestic product in most of the countries. The road accidents pose significant challenges to public safety and urban transportation management. There is a need to identify the high-risk area of accidents along with the critical day of week and vulnerable time period in order to implement effective preventive measures and optimizing the resource allocation. We collected 5,012 accident data from 대구교통종합정보. This study identified the high-risk locations, days of week, and time periods for accidents in Daegu and estimated the conditional probabilities of accidents occurring based on combinations of location, day of the week, and time period. The result is visualized in the form of dashboard in Tableau. This study holds substantial practical significance for urban planners, transportation authorities, and policymakers in Daegu to strategically allocate resources for traffic management, law enforcement, and targeted safety campaigns.

• Journal of Veterinary Clinics
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• v.41 no.2
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• pp.112-116
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• 2024

Uterine rupture is uncommon in small animals and can be caused by trauma, infection, dead fetus, or inappropriate obstetric techniques. A 4-year-old, intact female mixed-breed dog weighing 3 kg presented for elective ovariohysterectomy with a history of a motor vehicle accident two months previously. The patient showed no clinical signs of uterine abnormalities or evidence of pregnancy during physical examination. Clinical examinations, radiography, and ultrasonography revealed no significant findings. During ovariohysterectomy, a completely transected left uterine horn and dome-shaped ends were identified. The uterine layers were everted such that the endometrium could be seen outside the uterine horn. The dog recovered without post-operative complications and was discharged the following day. This report describes a rare case of an asymptomatic uterine rupture caused by trauma in a non-gravid dog.

• Journal of Drive and Control
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• v.21 no.1
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• pp.31-37
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• 2024

In this study, to prevent accidents in underground facilities during excavation, we developed a Lv.3 automated control system that can be configured as an electronic control system without changing the existing hydraulic system in a general excavator and utilized digital map information of underground facilities. We aimed to develop a strategy to prevent accidents caused by operator error. To implement this, a real-time excavator bucket end position recognition and control system was developed through angle measurement of the boom, arm, and bucket using an electronic joystick, RTK-GPS, and angle sensors. In addition, excavators are large, machine-based equipment, and it is difficult to control overshoot due to inertia with feedback control using position recognition information of the bucket tip. Therefore, feed-forward control is used to calculate the moving speed of the bucket tip in real-time to determine the target position. We developed a technology that can converge and verified the performance of the developed system through actual vehicle installation and field tests.