• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.8 no.6
• /
• pp.445-452
• /
• 2015

Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log and power intensity function (log linear, log power and exponential power), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure, using real data set for the sake of proposing log and power intensity function, was employed. This analysis of failure data compared with log and power intensity function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.3
• /
• pp.306-311
• /
• 2016

Software reliability in the software development process is an important issue. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, reliability software cost model considering logarithmic and exponential fault detection rate based on observations from the process of software product testing was studied. Adding new fault probability using the Goel-Okumoto model that is widely used in the field of reliability problems presented. When correcting or modifying the software, finite failure non-homogeneous Poisson process model. For analysis of software reliability model considering the time-dependent fault detection rate, the parameters estimation using maximum likelihood estimation of inter-failure time data was made. The logarithmic and exponential fault detection model is also efficient in terms of reliability because it (the coefficient of determination is 80% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, the software developers have to consider life distribution by prior knowledge of the software to identify failure modes which can be able to help.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.2
• /
• pp.201-207
• /
• 2015

Turbine-generator torsional response is caused by interaction between electrical transient air-gap torque and mechanical characteristics of turbine-generator shafts. If torsional shaft torque exceeds a certain threshold, the loss of fatigue life may occur and, in the end, it is possible to happen permanent shaft failure. Therefore, it is required to understand the torsional response for reliable operation and protection of turbine-generator shaft system. In this paper, we introduced multi-mass modeling method of turbine-generator shaft system using mechanical-electrical analogy and state-space equation to verify the transient torsional response based on ElectroMagnetic Transient Program (EMTP). These simple realization methods for turbine-generator shaft torsional response could be helpful to understand torsional interaction phenomena and develop the transient torque reduction countermeasures for turbine-generator shaft system.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2016.04a
• /
• pp.405-407
• /
• 2016

최근, ICT/loT 기술과의 융합은 다양한 산업분야에 적용되고 있으며, 안정적인 전력공급 및 지능형전력망 구축에 대해 다양한 연구가 이루어지고 있다. 특히, 수요라인과 직접적으로 연관된 배전계통의 효율적인 운영 및 배전설비의 유지/관리 기술에 대한 연구에 많은 연구를 수행하고 있다. 본 논문에서는 다양한 배전설비에 대한 환경정보를 loT 센서를 통해 수집함으로써 실시간으로 정전상황을 불러올 수 있는 기자재의 고장감지 및 예측을 위한 시스템 모델을 제안한다. 제안하는 시스템 모델은 실시간으로 수집되는 정보들에 대해 시계열 기반의 필터링 및 이상점 판단을 위한 성분 분석을 실시하고, 고장진단 및 예측을 위해 기계학습 기반의 데이터 분석실시하여 기자재들의 고장감지 및 고장 발생 여부를 예측한다.

• The Journal of Korean Association of Computer Education
• /
• v.5 no.2
• /
• pp.21-28
• /
• 2002

This paper proposes a new approach to rollback-recovery using multi-agent in distributed computing system. Previous rollback-recovery protocols are dependent on inherent communication and operating system, which causes a decline of computing performance in distributed computing system. By using multi-agent, we propose rollback-recovery protocol that is independent on operating system. We define three kinds of agent. One is a recovery agent that performs rollback-recovery protocol after a failure. Other is an information agent that constructs domain knowledge as a rule of fault tolerance and information during failure-free operation. The other is facilitator agent that controls the efficient communication between agents. Also we propose rollback-recovery protocol using multi-agent and simulated the proposed rollback-recovery protocol using JAVA and agent communication language in CORBA environment.

• Archives of design research
• /
• v.19 no.4 s.66
• /
• pp.5-16
• /
• 2006

This research premises that design failure in the market can stem partially from the gap between designer's communication intension through design and consumer's signification for design. Therefore, it's necessary that designers should examine and understand consumer's signification process for design factors or overall design images that they consider in the design process. For this, this research suggests that understanding consumer's signification process is possible by performing value categorization, consumer segmentation, value identification of main target consumers and relationship examination between value of target consumers and design attributes based on Means-End model by reviewing various theoretical backgrounds. In addition, this research suggests contents and methods for performing each step of understanding consumer's signification process. Also, Laddering was suggested as a method for the study and a case study was performed by it. Finally this research claims that understanding consumer's signification process can be one of the methods that decrease failure possibility rather increase success possibility of design in the market.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.3
• /
• pp.302-308
• /
• 2011

The HVAC(Heating Ventilation and Air Conditioning) system is only controlled by turn on/turn off operations with AC 380V input. Therefore, the efficiency of the system is reduced and accoustic noise problem occurs. Also, the blower is shut down at the AC power failure. In this paper, the inverter system with UPS function for the A/C(Air Conditioning) blower is proposed. Proposed inverter system which is powered from the AC and DC voltage can control speed, operation mode, and soft-start time using CAN communication. In case of the CAN communication failure, RS-232 communication could be used to control the hardware directly by the engineer that can solve existing problems. To verify the validity of proposed inverter system, simulations and experiments are carried out.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.12
• /
• pp.105-114
• /
• 2023

In this paper, we propose a deployment and operation scheme of UxNB network toward mobile IAB. By operating a UxNB network based on SDN(Software Defined Network), UxNBs are deployed in areas where mobile communication services are desired. After deploying UxNB in the service area, IAB can be set up to perform mobile communication services. For this purpose, this paper first proposes a UxNB Network Controller consisting of a UAV Controller and an SDN Controller, and proposes the necessary functions. Next, we present a scenario in which a UxNB network can be deployed and operated in detail step by step. We also discuss the location of the UxNB network controller, how to deliver control commands from the UAV controller to the UxNB, how to apply IAB for UxNB networks, optimization of UxNB networks, RLF(radio link failure) recovery in UxNB networks, and future research on security in UxNB networks. It is expected that the proposed UxNB Network Controller architecture and UxNB network deployment and operation will enable seamless integration of UxNB networks into Mobile IAB.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.3
• /
• pp.31-35
• /
• 2024

On October 7, 2023, Hamas launched a large-scale surprise attack against Israel and war broke out. On this day, in addition to supplying rockets, they directly invaded Israeli territory in multiple areas using parariders and motorcycles. Considering the security situation on the Korean Peninsula, it is meaningful to consider why Israel allowed Hamas to attack and why it failed to deter the war in advance. Deterrence can only be successful if it is supported by capability, will, communication, and credibility. Although the capability and will were sufficient, and the communication through punitive deterrence had been sufficiently communicated, the failure to deter this war was problematic in terms of credibility. In order to increase deterrence against North Korea's threat, we need to improve customized extended deterrence, convey the will of both Korea and the United States to deter, and increase credibility in deterrence capabilities and execution ability.

• Journal of Astronomy and Space Sciences
• /
• v.22 no.2
• /
• pp.175-186
• /
• 2005

In this paper, the development of the extended kalman filter(EKF) which is based on Koreasat-3 bus system is introduced and the design result is shown through the simulation. Especially to determine the filter gains for accurate estimation, there is assumed that initial estimated parameters are not changed. But although the satellite performs the attitude control by 2Hz, it is verified that the EKF is running rightly using the changed filter gains. Also some cases are considered using the simulation : with each bias for 4-axis gyro and with gyro each axis failure. It is verified that the designed filter can be used as the back-up about gyro failure.