• Journal of the Korean Society of Safety
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• v.9 no.4
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• pp.132-136
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• 1994

The new spray system is proposed by using a pipe with hygroscopic needle electrode In order to develop an air-cleaning ESP with high collection efficiency for submicron particles and high removal efficiency for NOx, SO$_2$, NH$_3$. Fundamental characteristics of charging water spray, which is not an usual wet type, are investigated experimentally. As a result, corona discharging mode and ozone generation rate are significantly affected by the operational conditions, such as the applied voltage and wet condition of the needle electrode.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.3
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• pp.157-165
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• 2022

As the number of the installed escalators in Korea continues to increase, the accident rate is also increasing. Therefore, it would be necessary to proactively secure safety. PESSRAE is a controller that implements safety functions as electric/electronic/programmable electronic devices to respond to risks that may occur in escalators. Safety Integrity Level (SIL) is assigned to the safety functions of PESSRAE and it must be verified that the quantitative target value according to the SIL level is satisfied. In this paper, the initial PESSRAE is analyzed using the FMEDA (Failure Mode, Effects and Diagnostic Analysis), which is a quantitative safety analysis method, and design improvement specifications are derived from the analysis in order to satisfy the quantitative target values. Based on the derived design specifications, the improved PESSRAE controller was manufactured. And the appropriateness of the design was verified experimentally in a testbed environment simulating the real environment.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.838-843
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• 1998

Risk importance measures are widely wed to rank risk contributors in risk-based applications. Typically, Fussell-Vesely (F-V) importance and risk achievement worth (RAW) are used in the component importance raking for the reliability centered maintenance (RCM) analysis of safety system in nuclear power plants (NPPs). This study was performed as part of feasibility study on RCM for domestic NPPs, which is focused on the component importance ranking approach the maintenance recommendation. The approach of modulizing faulting tree basic events was applied in the simplification process of the PSA model and the validity of the approach was evaluated As a result of the case study, this paper included the importance and the maintenance recommendations for the safety-related equipments associated with safety injection and containment spray in large loss of coolant accident sequences.

• International Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.31-37
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• 2015

Passenger plane flying motion graphics is very important for route, control of the flight altitude and passenger safety. For all that, it is quite useful for route away from the disruptive influences such as vibrations caused by storms or turbulence during the flight and in processes such as re-arrest of the specified route. Therefore, the response time against the adverse effects of the shape and the system is so necessary for both safety and comfort. In this study motion and route graphics were obtained under the control of an airliner C # interface with the program. In this way, graphics were obtained in solving the equations of motion in short time and design time was shortened.

• The Journal of Korean Medicine
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• v.44 no.1
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• pp.128-128
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• 2023

Objectives: This research aimed to develop a guideline for evaluating safety and performance of electronic warm-acupuncture apparatus. With the development of medical devices like electronic warm-acupuncture apparatus with improved performance, convenience and safety measures compared to traditional warm-acupuncture needling, safety and performance guideline is a necessity. Methods: By referring to existing standards and guidelines of other electronic devices for Korean medicine with heating function, guideline for safety and performance assessment of electronic warm-acupuncture apparatus was drafted Results: The guideline, presents explanation for adequate temperature and settings of the apparatus, and safety measurements providing against thermal runaway situations along with guidelines for the manual. Guideline for detailed test method for the performance of the apparatus such as accuracy of temperature increase and the timer, and safety unit was also provided. The test items and suggested test methods for the requirements of biological, electrical and electromagnetic safety were referred to Korean approval documents of ministry of Food and Drug Safety. Conclusion: We proposed the relevant items to verify performance and safety of warm-acupuncture apparatus to assure patient safety and improve the quality of currently developing devices for application in clinical field.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.120-128
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• 2004

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, the electronic equipment of a satellite consists of an aluminum case containing PCB. Each PCB has resistors and IC. Noise and vibration of the wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation, random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when the frequency of random vibration meets with natural frequency of PCB, fatigue fracture may occur in the part of solder joint. The launching environment, thus, needs to be carefully considered when designing the electronic equipment of a satellite. In general, the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM or vibration test. In this study, the natural frequency and dynamic deflection of PCB are measured by FEM, and the safety of the electronic components of PCB is evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs ranging from the electronic equipments of a satellite to home electronics.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.6
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• pp.267-276
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• 2021

The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

• Journal of Applied Reliability
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• v.15 no.1
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• pp.27-32
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• 2015

Functional safety is part of the overall safety relating to the equipment under control (EUC) and the EUC control system that depends on the correct functioning of the electrical/electronic/programmable electronic (E/E/PE) safety-related systems. Since the complexity of the medical equipment is increased, manufactures have to obtain functional safety as well as basic safety. This study proposes a perspective for applying functional safety to medical equipment. The research is carried out with respect to overall safety life-cycle of functional safety and essential performance of the medical equipment. The relationship between functional safety and essential performance is identified centered on the safety function. The essential performance using E/E/PE systems is defined as a safety function of functional safety. This approach is applied to a ultrasound imaging system as a case study.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.81-87
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• 2008

The reliability prediction and evaluation for general electronic components are required to guarantee in quality and in efficiency. Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. In this study reliability prediction of electronic components, that is the interface card, which is used in the CNC(Computerized Numerical Controller) of machine tools, was carried out using PRISM reliability prediction specification. Reliability performances such as MTBF(Mean Time Between Failure), failure rate and reliability were obtained, and the variation of failure rate for electronic components according to temperature change was predicted. The results obtained from this study are useful information to consider a counter plan for weak components before they are used.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.49-58
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• 2017

This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and POP(Point of Production) terminal through electronic document server and electronic pen, bluetooth receiver and form paper in disassembly and process inspection works. The proposed model shows that the new method by electronic document automation system can more efficiently perform to reduce processing time for maintenance work, compared with the current approach by handwritten processing system. It is noted in case of the method by electronic document automation system that the effects of proposed model are as follows; (a) While the processing time per equipment for maintenance by the current method was 300 minutes, the processing time by the new method was 50 minutes. (b) While the processing error ratio by the current method was 20%, the error ratio by the new method was 1%.