• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.205-211
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• 2020

Wiring defect is a major concern for safe aircraft operations. However, troubleshooting process of a wiring defect is very difficult due to extensive and complex wiring system and installed location. Recently, time domain reflectometer (TDR) equipment that enables effective defected wiring troubleshooting has been introduced. Unfortunately, TDRs have not practically adopted by most of airlines' maintenance departments because the effectiveness and usefulness of TDRs have not been verified. This study was conducted to verify if TDRs can identify the location and type of defected aircraft wiring, and whether they can be applied for troubleshooting purposes. Experimental plan was established by using various wires and connections applied to actual aircraft and the observed results were compared with the TDR operation guide. The usability of the TDR in actual aircraft wiring defect detection may be acceptable as the experimental results showed similar results to the TDR operation guide.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.38-42
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• 2012

This paper describes electrical fire on residential environment such as apartment and detached house caused by defect of interior wiring. We carried out experimental study on short circuit characteristics by the interior wiring length. We were measured arc current, arc energy and interrupting time of earth leakage current circuit breaker(ELB), when an interior wiring break out short circuit in residential environment. From the experiment results, the longer of the interior wiring, the magnitude of arc current decreased and the interrupting time of ELB increased. When applied the A maker's ELB, the strength of arc current and interrupting time of ELB was 254 A and 245 ms respectively at 30 m interior wiring length. In 3 m interior wiring length, arc current and interrupting time was 716 A and 4.24 ms respectively. Arc energy was dependent on the magnitude of arc current and the interrupting time of ELB, the longer the interrupting time, arc energy increasing. In this paper, minimum arc energy was 277 J using C maker's ELB and 3 m interior wiring length(arc current 283 A, interrupting time of breaker 6.28 ms). Therefore in the residential environment, short circuit caused by defect of the interior wiring lead to electrical fire.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.4
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• pp.116-121
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• 2018

According to the incresement of aging aircraft, Republic of Korea Air Force (RoKAF) conducted a teardown inspection of aircraft's EWIS (electrical wiring interconnection system) to determine the status of deterioration and the influence of failure occurrences due to it. The inspected aircraft were the retired fighter jets that had been used for more than 40 years. By analyzing defect type and the defect tendency, RoKAF can establish the necessary measures for the usage extension of their fleet and furthermore, the analysis results can be used as a basic data for the preparation of it's aircraft aging. EWIS inspection was done throughout careful visual inspection technique by removing all the ducts and pipes located in the fuselage and wings. For the aircraft wiring where no damage was found, the elongation tests were performed to determine the deterioration of wiring according to the location of the aircraft. The connectors, which is the main cause of intermittent failure, were completely disassembled and inspected for internal damage such as corrosion, abrasion, and traces of foreign objects. The detected defects were classified into 4 severity levels based on the type of damage, and the classified defects were weighted according to the criticality which may affects to it's system to establish the action plan.

• Journal of Veterinary Clinics
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• v.33 no.2
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• pp.124-128
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• 2016

A 7-year-old intact female Maltese dog presented with a history of bite wounds. Physical examination revealed labored breathing, four puncture wounds with subcutaneous emphysema of the thorax, and paradoxical respiratory movement of the right thoracic wall. On radiography, a segmental fracture of the right 7th rib and a single fracture of the 8th rib were evident on the dorsal thorax. An inward displacement of the fractured segment and contusion of the right caudal lung lobe were identified with computed tomography. A diagnosis of pseudo-flail chest was made. Exploratory thoracotomy revealed a full-thickness muscular defect, a marked discoloration of the right caudal lung lobe, a segmental fracture of the right 7th rib, and a single fracture of the right 8th rib. Necrotic tissues were removed using surgical debridement. The fractured 7th and 8th ribs were corrected using a single interfragmentary wiring technique. The thoracic wall was reconstructed using the latissimus dorsi muscle flap. Additional thoracic stabilization using a thermoplastic splint was applied to correct paradoxical respiratory movement. The external splint was removed 4 weeks postoperatively. There was no evidence of respiratory abnormalities 18 months postoperatively.

• Journal of Chest Surgery
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• v.50 no.6
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• pp.460-462
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• 2017

We herein present the unique case of a 68-year-old male diabetic patient who developed sterile necrosis of the sternum 1 month after myocardial revascularization with the use of bilateral internal thoracic artery grafts. The sternum had been closed by the bilateral Robicsek wiring technique. The sternum was removed, and bilateral pectoralis major flaps were used to cover the defect. The patient had an uneventful recovery.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.558-559
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• 2018

The harness wiring serves as an intermediary for transmitting the electrical signals necessary to drive the vehicle and is highly influenced by vehicle performance. Wire harness tester performs assembly test. Harness products are operated with the function of checking 0 and 1. Proceed to inspection in wire assembly process. There is a defect in the finished vehicle during use. We want to improve such defects. We design the FPGA and propose the measurement device design and the simulation result that the line and the line are disconnected by ADC precision harness inspection.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1669-1674
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• 2017

In this study, We have discussed the development of a diagnostic device to detect and prevent electrical fire due to the arc caused by contact failure and partial disconnection at the connection part of the three-phase electric heater wiring used in the industrial field. The arc caused by contact failure and partial disconnection at the connection part of the electric heater shows a change in the current effective value. Therefore, it is possible to determine whether there exists a defect by analyzing the current unbalance factor and the number of current fluctuations with the diagnostic apparatus. The three-phase unbalanced heater is considered to be capable of determining defects through periodic measurement and trend analysis of the current unbalance factor. It is also expected that this device can be used not only for electric heaters but also for detection of defects in wiring and connections of electrical equipment having a characteristic of constant load current.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.6
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• pp.11-16
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• 2021

In this paper, a quality inspection system was developed to identify the defective assembly of connectors used in automobile wiring. For waterproof connectors, an internal seal must be inserted for waterproofing. However, there are cases where it is omitted or double-inserted during production. An automatic inspection jig was designed using photosensors and touch switches to classify good and bad connector components. In the case of the existing visual inspection, 6,400 connectors were inspected when 5 people inspected for 8 hours. However, when using the inspection jig developed under the same conditions, 20,000 pieces were inspected. In other words, the productivity is greatly improved compared to the conventional visual inspection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.181-189
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• 2019

An aircraft power distribution device distributes and controls the power generated by the generator and provides overcurrent protection. There are many defect phenomena that make AC power distribution impossible during flight, which poses a problem in because some electronic equipment cannot be operated. We describe a process of deriving the root cause of defects by using vibration testing equipment to simulate the vibration conditions during aircraft flight, which result in defects. The results show that the cause of the defect is internal wiring damage caused by the vibration of the contactor of the AC power distribution device. Therefore, the shape of the contactor was improved to solve this problem. We also improved the test procedure by performing defect detection tests using vibration testing equipment to detect a faulty contactor. As a result of the improvements, a component certification test and flight test proved that the defect phenomena of the AC electrical master box were improved.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.354-356
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• 2006

In this paper, the position control performance of networked control systems is analyzed when time delay through the network is considered. Integrating a control system into a network has great advantages over the traditional control system which uses point to point connection: it allows remarkable reduction in wiring, makes it easy to install and maintain the system, and improves compability. However, a networked control system has the critical defect that network uncertainties, such as time delay, can degrade the control system's performance. Therefore, the major concern of a networked control system is analyzing the effect of network uncertainties. This paper is concerned with PID controller performance for stability region, critical stability region and unstability region under the time delay in the Controller Area Network.