• 항공우주시스템공학회지
• /
• 제7권2호
• /
• pp.29-34
• /
• 2013

Safety requirements for aircraft and system functions include minimum performance constraints for both availability and integrity of the function. These safety requirements should be determined by conducting a safety assessment. The depths and contents of aircraft system safety assessment vary depending on factors such as the complexity of the system, how critical the system is to flight safety, what volume of experience is available on the type of system and the novelty and complexity of the technologies being used. Requirements that are defined to prevent failure conditions or to provide safety related functions should be uniquely identified and traceable through the levels of development. This will ensure visibility of the safety requirements at the software and electronic hardware design level. This paper has prepared to study on promoting the efficiency of establishing hierarchical safety requirements from aircraft level function to item level through system safety processes.

• 전기학회논문지P
• /
• 제65권4호
• /
• pp.242-249
• /
• 2016

The railway system is being converted to the computer system from the existing mechanical device, and the dependency on software is being increased rapidly. Though the size and degree of complexity of software for railway system are slower than the development speed of hardware, it is expected that the size will be grown bigger gradually and the degree of complexity will be increased also. Accordingly, the validation of reliability and safety of embedded software for railway system was started to become influential as the important issue. Accordingly, various software test and validation activities are highly recommended in the international standards related railway software. In this paper, we presented a software coding analysis tool using symbolic execution for railway system, and presented its result of implementation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 D
• /
• pp.2166-2168
• /
• 2001

Reactor Noise is defined as the fluctuations of measured instrumentation signals during full-power operation of reactor which have informations on reactor system dynamics such as neutron kinetics. The Reactor internal structures which consist of many complex components are subjected to flow-induced vibration due to high temperature and pressure in reactor coolant system. The above flow-induced vibration causes degradation of structural integrity of the reactor and may result in loosing mechanical binding component which might impact other equipment and component or cause flow blockage. It is important to analyze reactor noise signal for the early detection of potential problem or failure in order to diagnosis reactor integrity in the point of view of safety and plant economics. Detailed design of hardware diagnostic system reactor internal structures using neutron noise(RIDS).

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.81-83
• /
• 2005

The Reactor Protection System (RPS) is a very important system in a nuclear power plant because the system shuts down the reactor to maintain the reactor core integrity and the reactor coolant system pressure boundary if the plant conditions approach the specified safety limits. This paper describes the unavailability assessment of a digital reactor protection system using the fault tree analysis technique. The fault tree technique can be expressed in terms of combinations of the basic event failures. In this paper, a prediction method of the hardware failure rate is suggested for a digital reactor protection system. and applied to the reactor protection system being developed in Korea.

• 시스템엔지니어링학술지
• /
• 제14권2호
• /
• pp.73-82
• /
• 2018

In this work, a hardware based cryptographic module for the cyber security of nuclear power plant is developed using a system engineering approach. Nuclear power plants are isolated from the Internet, but as shown in the case of Iran, Man-in-the-middle attacks (MITM) could be a threat to the safety of the nuclear facilities. This FPGA-based module does not have an operating system and it provides protection as a firewall and mitigates the cyber threats. The encryption equipment consists of an encryption module, a decryption module, and interfaces for communication between modules and systems. The Advanced Encryption Standard (AES)-128, which is formally approved as top level by U.S. National Security Agency for cryptographic algorithms, is adopted. The development of the cyber security module is implemented in two main phases: reverse engineering and re-engineering. In the reverse engineering phase, the cyber security plan and system requirements are analyzed, and the AES algorithm is decomposed into functional units. In the re-engineering phase, we model the logical architecture using Vitech CORE9 software and simulate it with the Enhanced Functional Flow Block Diagram (EFFBD), which confirms the performance improvements of the hardware-based cryptographic module as compared to software based cryptography. Following this, the Hardware description language (HDL) code is developed and tested to verify the integrity of the code. Then, the developed code is implemented on the FPGA and connected to the personal computer through Recommended Standard (RS)-232 communication to perform validation of the developed component. For the future work, the developed FPGA based encryption equipment will be verified and validated in its expected operating environment by connecting it to the Advanced power reactor (APR)-1400 simulator.

• 비파괴검사학회지
• /
• 제27권6호
• /
• pp.483-500
• /
• 2007

Emerging sensor-based structural health monitoring (SHM) technology can play an important role in inspecting and securing the safety of aging civil infrastructure, a worldwide problem. However, implementation of SHM in civil infrastructure faces a significant challenge due to the lack of suitable sensors and reliable methods for interpreting sensor data. This paper reviews recent efforts and advances made in addressing this challenge, with example sensor hardware and software developed in the author's research center. It is proposed to integrate real-time continuous monitoring using on structure sensors for global structural integrity evaluation with targeted NDE inspection for local damage assessment.

• 한국컴퓨터정보학회지
• /
• 제14권2호
• /
• pp.205-214
• /
• 2006

유비쿼터스 컴퓨팅 시대의 업무를 위하여 인터넷을 통한 원격 접속이 필요하고, 입력되는 ID와 패스워드에 대한 기밀성 무결성의 네트워크 보안을 위하여 OTP를 적용하고 있다. 현재의 OTP는 Token이라는 하드웨어를 보유하고 있어야 하며, 보안에서도 취약점이 있다. 본 논문에서는 OTP 네트워크에 스니핑 도구를 설치하고, Cain을 이용하여 ARP Cache poisoning 공격을 시행하여 사용자 암호에 대하여 스니핑으로 취약점을 확인한다. 새로운 보안 방안으로 Tokenless OTP를 적용할 수 있는 새로운 시스템을 제안하고, 기밀성과 무결성을 보장하고자 한다. 외부에서 원격 접속 시 Tokenless OTP를 활용하여 접근제어를 위한 테스트를 하고, 접속에서 인증시스템과 연동하여 접속제어를 할 수 있었다. 만약 인증과정에서 해킹을 당해도 사용자만이 알고 있는 핀 번호 없이는 접속이 불가능하다는 것이 확인되었다. 이 결과 Tokenless OTP를 적용할 시에 패스워드의 유출 및 오용과 해킹에 대한 방어가 되어 보안성을 강화하고, 안전성을 높이는 보안 시스템으로 평가되었다.

• 한국컴퓨터정보학회논문지
• /
• 제12권1호
• /
• pp.107-116
• /
• 2007

유비쿼터스 컴퓨팅 시대에서 업무를 위하여 인터넷을 통한 원격 접속을 할 때, 정보보안을 위해 입력되는 ID와 패스워드에 대한 기밀성, 무결성의 네트워크 보안을 위하여 OTP를 적용하고 있다. 현재의 OTP는 Token이라는 하드웨어를 보유하고 있어야 하며, 보안에서도 취약점이 있다. 본 논문에서는 OTP 네트워크에 스니핑 도구를 설치하고, Cain을 이용하여 ARP Cache poisoning 공격을 시행하여 사용자 암호에 대하여 스니핑으로 취약점을 확인한다. 새로운 보안 방안으로 Tokenless OTP를 적용할 수 있는 새로운 시스템을 제안하고, 기밀성과 무결성을 보장하고자 한다. 외부에서 원격 접속 시 Tokenless OTP를 활용하여 접근제어를 위한 테스트를 하고, 접속에서 인증시스템과 연동하여 접속제어를 할 수 있었다. 만약 인증과정에서 해킹을 당해도 사용자만이 알고 있는 핀 번호 없이는 접속이 불가능하다는 것이 확인되었다. 이 결과 Tokenless OTP를 적용할 시에 패스워드의 유출 및 오용과 해킹에 대한 방어가 되어 보안성을 강화하고, 안전성을 높이는 보안 시스템으로 평가되었다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 학술대회 논문집
• /
• pp.371-374
• /
• 2004

Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

• 대한의용생체공학회:의공학회지
• /
• 제44권6호
• /
• pp.428-442
• /
• 2023

In this study, we have a goal to develop usability evaluation guidelines for heuristic-based artificial intelligence-based Software as a Medical Device (SaMD) in the medical field. We conducted a gap analysis between medical hardware (H/W) and non-medical software (S/W) based on ten heuristic principles. Through severity assessments, we identified 69 evaluation domains and 112 evaluation criteria aligned with the ten heuristic principles. Subsequently, we categorized each evaluation domain into five types, including user safety, data integrity, regulatory compliance, patient therapeutic effectiveness, and user convenience. We proposed usability evaluation guidelines that apply the newly derived heuristic-based Software as a Medical Device (SaMD) evaluation factors to the risk management process. In the discussion, we also have proposed the potential applications of the research findings and directions for future research. We have emphasized the importance of the judicious application of AI technology in the medical field and the evaluation of usability evaluation and offered valuable guidelines for various stakeholders, including medical device manufacturers, healthcare professionals, and regulatory authorities.