• Title/Summary/Keyword: Software and system safety

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A Study on the Conversion Time to Minimize of Transient Response during Inter-Conversion between Control Laws (제어법칙 간 상호 전환 시 과도응답 최소화를 위한 전환시간에 관한 연구)

  • Kim, Chongsup
    • Journal of Aerospace System Engineering
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    • v.9 no.1
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    • pp.12-18
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    • 2015
  • The inter-conversion between different control laws in flight has a lot of risk. The SWM(Switching Mechanism) including logic and stand-by mode is designed to analyze the transient response of aircraft during inter-conversion between different control laws, based on the in-house software for non-real-time and real-time simulation. The SWM applies the fader logic of TFS(Transient Free Switch) to minimize the transient response of an aircraft during the inter-conversion, and applies the reset '0' type of the stand-by mode to prevent surface saturation due to integrator effect in the disengaged flight control law. The transition time is also important to minimize the objectionable transient response in the inter-conversion, as well as the transition control law design. This paper addresses the results of non-real-time simulation for the characteristics of transient response to different transition time to select the adequate transient time, and the real-time pilot evaluation, using SSWM(Software Switching Mechanism) and HSWM(Hardware Switching Mechanism), which is met for Level 1 flying qualities and assures safety of flight.

The Design and Implementation of a Fault Diagnosis on an Electronic Throttle Control System (전자식 스로틀 제어시스템을 위한 오류 자기진단 기능 설계 및 구현)

  • Kang, Jong-Jin;Lee, Woo-Taik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.6
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    • pp.9-16
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    • 2007
  • This paper describes the design and implementation of the fault diagnosis on the Electronic Throttle Control(ETC) System. The proposed fault diagnosis consists of an input signal, actuator and a processor diagnosis. The input signal diagnosis can detect the faults of the ETC system's input signals such as the position sensor fault, source voltage fault, load current fault, and desired position fault. The actuator diagnosis is able to detect the actuator fault due to the actuator aging and an obstacle which interfere in the movement of the actuator. The processor diagnosis detects the fault which prevents the microprocessor from operating the ETC software. In order to protect the breakdown of the ETC system and assure the driving safety, appropriate reactions are also proposed according to the detected faults. The safety and reliability of the ETC system can be improved by the proposed fault diagnosis.

Design and Analysis of Load Shedding for the Electric Propulsion System (전기추진시스템의 부하저감 설계 및 해석)

  • Kim, Kyung-Hwa;Kim, Dae-Heon;Lee, Seok-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.7
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    • pp.971-977
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    • 2015
  • The electric propulsion system requires more reliability and safety than the conventional propulsion system because any sudden changes of electric system would bring tremendous effects on the ship's safety and propulsion. So it is very important to consider the potential transient effects. This paper discusses one of the worst electric accident. That is, one or two of generators are out of service in normal seagoing condition. And the appropriate measures are simulated in order to prevent the frequency decline that can bring the other generator's tripping. In addition, the relation between the transient effects and the major factors(inertia of generator/motors, governor's drooping characteristic and response speed) are also identified using the ETAP software.

A Study on selection of the Type and the Technique for the Hazard Analysis of the Train Control System(mock-up) (열차제어시스템(mock-up)의 위험원 분석을 위한 Type과 Technique의 선정에 대한 연구)

  • Han, Chan-Hee;Lee, Young-Soo;Ahn, Jin;Jo, Woo-Sic
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.614-622
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    • 2008
  • It has been studying actively that the process and the methodology for the safety security of the system suggested from international standards and domestic/abroad materials in Korea. However, these process & methodology can generate a lot of errors and deficiencies because the system is applied without considering the system characteristics and its scope (such as hardware, software, interface, etc.). Therefore, the type is defined as the safety process with the basis on general development process in this study, the potential hazards of the mock-up system which is developed are extracted thorough selecting a technique according to each type. In addition to it, the effect is compared and analyzed with various technique selection by each phase of the development process.

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Case Study of Applying DO-278A for Advanced Surface Movement Guidance & Control System (DO-278A 표준을 적용한 A-SMGCS 개발 사례 연구)

  • Jo, Sanghoon;Lee, Hongseok;Kim, Jha-young;Yi, Jin-geun
    • Journal of Advanced Navigation Technology
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    • v.20 no.2
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    • pp.127-133
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    • 2016
  • This paper proposes a case study of applying to DO-278A, which is a software development standard of ground aviation equipment in communication, navigation, surveillance/air traffic management (CNS/ATM) domain, in order to develop software of Advanced surface movement, guidance and control system (A-SMGCS). It explains considerations to application of DO-278A standard, discusses how to tailor processes or requirements specified in DO-278A in detail, and explain tailored results. And it also summary problems or issues occurred during application of DO-278A, which can be appeared when DO-278A is applied to for the first time by any development part. These are required considerations in order to reduce trial and error. To the conclusion, it explains lessons learned from application of DO-278A and suggest how to solve these problems or issues.

Development of Accident-prevention Smart Monitoring System for Woman Diver using Zigbee Module and GPS Sensor (Zigbee와 GPS를 이용한 해녀 사고예방 스마트 모니터링 시스템 개발)

  • Choi, Min Ho;Kim, Young Sang
    • Smart Media Journal
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    • v.5 no.3
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    • pp.74-80
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    • 2016
  • In this paper, we propose an accident-prevention smart monitoring system for Haenyeo(Woman diver) using Zigbee module and GPS sensor. This system can collect such information as the diving location, the body temperature, the depth of diving, and the diving time of a Woman diver working under the water and then respond immediately to an accident occurring. The research developed a smart Teawak and smart swimming goggles which can measure the state of a Woman diver and her diving activities. Smart Teawak, the buoy tool while a Woman diver is collecting seafoods under water, is able to receive GPS and transmit the data from smart swimming goggles and Zigbee Module to IHSS(IoT based Haenyeo Safety service Software) server. In addition, IHSS, a responsive web, provides the diving location and the state of a Woman diver on the smart phone. As a result, the system will be useful in the aspects of Woman diver' health care and the safety, furthermore, which will significantly contribute to global marketing of Woman diver with its being designated as a UNESCO intangible cultural asset.

Support of shaft process line Modeling for improving operation rate (Shaft 가공라인 자원 가동률 향상을 위한 모델링)

  • Lim, Sang-Baek;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.18 no.4
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    • pp.179-183
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    • 2016
  • The purposes of this research are to modelize test system of SM TESTING by ARENA, software, input several items of specimen's testing process, resources of system and transfer loop, etc, give a hypothesis and then, obtain results reducing the efficiency of the whole system finally by overload of specific facilities in the testing system through the simulation so as to obtain several materials such as specimen and testing facility, transfer loop, etc. by simple and various forms without any necessity of numerical modelization. It will add facilities of over load and reduce facilities with low operation rate, so increase the efficiency of the system.

Safe Adaptive Headlight Controller with Symmetric Angle Sensor Compensator for Functional Safety Requirement (기능 안전성을 위한 대칭형 각도센서 보상기에 기반한 안전한 적응형 전조등 제어기의 설계)

  • Youn, Jiae;Yin, Meng Di;An, Junghyun;Cho, Jeonghun;Park, Daejin
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.5
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    • pp.297-305
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    • 2015
  • AFLS (Adaptive front lighting System) is being applied to improve safety in driving automotive at night. Safe embedded system for controlling head-lamp has to be tightly designed by considering safety requirement of hardware-dependent software, which is embedded in automotive ECU(Electronic Control Unit) hardware under severe environmental noise. In this paper, we propose an adaptive headlight controller with newly-designed symmetric angle sensor compensator, which is integrated with ECU-based adaptive front light system. The proposed system, on which additional backup hardware and emergency control algorithm are integrated, effectively detects abnormal situation and restore safe status of controlling the light-angle in AFLS operations by comparing result in symmetric angle sensor. The controlled angle value is traced into internal memory in runtime and will be continuously compared with the pre-defined lookup table (LUT) with symmetric angle value, which is used in normal operation. The watch-dog concept, which is based on using angle sensor and control-value tracer, enables quick response to restore safe light-controlling state by performing the backup sequence in emergency situation.

Si/SiO2 Multilayer-based Fabry-Perot Filter for 4.26 ㎛ Filtering in Carbon Dioxide Detection (이산화탄소 감지를 위한 4.26 ㎛ 필터용 poly-Si/SiO2 다층 박막 기반의 패브리 페로-필터)

  • Do, Nam Gon;Lee, Junyeop;Jung, Dong Geon;Kong, Seong Ho;Jung, Daewoong
    • Journal of Sensor Science and Technology
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    • v.30 no.1
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    • pp.56-60
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    • 2021
  • In this study, the relationship between the transmitted light intensity and full-width-at-half-maximum (FWHM) of a Fabry-Perot filter was investigated. The measured refractive indices and absorption coefficients of the fabricated thin films were applied to the Fabry-Perot filter via simulations using optical software. Although considerable research has been conducted on Fabry-Perot filters, this study focused on the usefulness of 4.26-㎛ infrared filtering in carbon dioxide detection. Optical analysis was performed considering the effects of the thickness, refractive indices, and number of thin films in a distributed Bragg reflector. Ultimately, a clear trade-off relationship was observed wherein the transmitted light intensity decreased as the number of multilayers increased; however, the FWHM was observed to be narrower.

Deep Learning Based User Safety Profiling Using User Feature Information Modeling (딥러닝 기반 사용자 특징 정보 모델링을 통한 사용자 안전 프로파일링)

  • Kim, Kye-Kyung
    • Journal of Software Assessment and Valuation
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    • v.17 no.2
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    • pp.143-150
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    • 2021
  • There is a need for an artificial intelligent technology that can reduce various types of safety accidents by analyzing the risk factors that cause safety accidents in industrial site. In this paper, user safety profiling methods are proposed that can prevent safety accidents in advance by specifying and modeling user information data related to safety accidents. User information data is classified into normal and abnormal conditions through deep learning based artificial intelligence analysis. As a result of verifying user safety profiling technology using more than 10 types of industrial field data, 93.6% of user safety profiling accuracy was obtained.