• Nuclear Engineering and Technology
• /
• 제51권3호
• /
• pp.692-701
• /
• 2019

Recently, instrumentation and control (I&C) systems in nuclear power plants have undergone digitalization. Owing to the unique characteristics of digital I&C systems, the reliability analysis of digital systems has become an important element of probabilistic safety assessment (PSA). In a reliability analysis of digital systems, fault-tolerant techniques and their effectiveness must be considered. A fault injection experiment was performed on a safety-critical digital I&C system developed for nuclear power plants to evaluate the effectiveness of fault-tolerant techniques implemented in the target system. A software-implemented fault injection in which faults were injected into the memory area was used based on the assumption that all faults in the target system will be reflected in the faults in the memory. To reduce the number of required fault injection experiments, the memory assigned to the target software was analyzed. In addition, to observe the effect of the fault detection coverage of fault-tolerant techniques, a PSA model was developed. The analysis of the experimental result also can be used to identify weak points of fault-tolerant techniques for capability improvement of fault-tolerant techniques

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 1987년도 춘계학술발표회 논문집
• /
• pp.82-85
• /
• 1987

This paper describes the technology for the improvement of subxdriber loop utilization. Nearly all customer loops are now carried at voice frequency on individual wire pairs. Reenct digital technology improvements together with the increasing cost of wire, have resulted in some penetration of carrier systems into the loop plant. Moreover the increasing use of local digital switching systems should permit digital carrier systems to become an important factor in the loop plant in the future.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
• /
• pp.383-388
• /
• 1991

This paper analizes two numerical integration methods, both based on the Runge Kutta 4-th order formula for deterministic systems, for digital simulation of a differential equation driven by white noise. It is shown that a "standard' Runge Kutta method for stochasitic systems yields solutions of Stratonovich differential equations, while Riggs and Phillips' method results in solutions of Ito differential equations. Therefore the white noise differential equation must be converted into the equivalent Ito equation before the latter method is used. Digital simulation results for a simple differential equation are also presented.nted.

• ETRI Journal
• /
• 제32권1호
• /
• pp.154-156
• /
• 2010

Oscillation-based testing of analog-to-digital converters represents a viable option for low-cost built-in self-testing in mixed-signal design. While numerous papers have addressed implementation issues, little attention has been paid to the measurement accuracy. In this letter, we highlight an inherent measurement uncertainty which has to be considered when deriving the parameters from the oscillation frequency.

• Journal of Ship and Ocean Technology
• /
• 제8권4호
• /
• pp.45-55
• /
• 2004

How to achieve engineering collaboration among diverse engineering activities is one of the key topics in manufacturing fields nowadays. The infrastructure for collaborative engineering is essential, and it can be realized by information technologies and intelligent engineering applications in digital environments. Digital Manufacturing is a technology to facilitate effective product developments and agile productions by computer models representing the physical and logical schema and the behavior of real manufacturing systems including products, processes and factories. A digital factory as a well-designed and integrated digital environment is incorporated in it. In this paper, digital manufacturing is recommended as a good strategy for collaborative engineering, especially in product developments and productions. By business process analysis and some case studies, we suggested sophisticated digital models are very useful to concurrent and collaborative engineering. It is expected that digital manufacturing is a very good strategy for achieving dramatic time and cost savings in many engineering activities of many manufacturing industries, including machinery, automotive and shipbuilding.

• Asian Journal of Innovation and Policy
• /
• 제11권2호
• /
• pp.183-201
• /
• 2022

The purpose of this article is to provide preliminary findings on the state of digital technology applications of startups in Southeast Asia and to discuss issues related to digital health adoption in the region. This exploratory study is based on an empirical analysis of startups and digital technology applications information from various publicly available website databases. Public and private organizations would benefit from a better understanding of the current state of digital technology applications provided by startups and the challenges faced in digital health adoption. This article contributes to the existing literature by offering an overview of startups and digital technology applications in the digital health space in the fast-growing region of Southeast Asia. It offers advice to organizations intending to pursue healthtech initiatives on the types of health services provided by startups and issues that need to be addressed to increase the adoption rate.

• 한국실내디자인학회논문집
• /
• 제14권5호
• /
• pp.226-235
• /
• 2005

Since the late 20th century, digital technology has changed our environment in many ways. The representative advanced homes today embed digital facilities such as a sensor infrastructure, a networking system, and ubiquitous display. In this point of view, this study was intended to define the apartment residents' diverse needs for digital home design. The subjects are 400 wives who live in Busan. The findings are as follows; (1) The factors of the housing activities are extracted as 'guest hosting,' 'family entertaining,' 'digital network,' 'daily domestic affair,' 'non-daily domestic affair,' 'media using,' and 'bathing & exercising' activities. (2) The 'digital network activities' occurred more frequently in the households with non-employed wife and preschool children, and with employed wife and preschool and elementary school children. (3) The factors of the digital home system were extracted as 'safety & maintenance,' 'health & convenience,' 'educational & housekeeping,' and 'cultural & entertaining' systems. (4) The needs of non-employed wives for the safety & maintenance and the educational & housekeeping systems are varied by family life cycle and wife age. While, the needs of employed wives for the educational & housekeeping and the culture & entertaining systems are varied by dwelling-size and wife age.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
• /
• pp.279-282
• /
• 2000

As digital systems continue to use components with faster edge rates and clock speeds, transmission of the digital information in these systems approaches the microwave realm. At these speeds digital signal fidelity becomes both a critical success factor and design challenge. The noise sources in digital systems include the noise in power supply, ground and packaging media due to simultaneous switching of drivers, signal reflections and distortions on single and multiple transmission lines. This paper presents theory, case studies and design considerations of gigabit interconnection for network and communication systems. The case studies show HSPICE and Ampredictor simulations of alternate approaches. Various subjects including skin effect and dielectric losses, interconnect simulations and crosstalks of connector, affected signal discontinuity, are addressed.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
• /
• pp.176-179
• /
• 2000

This paper addresses a fuzzy controller for nonlinear systems control using a pole placement in a specified disk and fuzzy controller is redesign for Intelligent digital redesign method. for nonlinear system, we obtain continuous time state feedback gain that guarantee stability of globally TS fuzzy system. The feedback gain is satified pole placement in a specified disk region so that the closed loop system is stable, For digital control redesgin of continuous time TS fuzzy model, we does state matching and obtain feedback gain of digital controller. Finally, it is shown that the proposed method is feasible through a computer simulation.

• International Journal of Control, Automation, and Systems
• /
• 제4권4호
• /
• pp.506-515
• /
• 2006

This paper studies an intelligent digital control for nonlinear systems with multirate sampling. It is worth noting that the multirate control design is addressed for a given nonlinear system represented by Takagi-Sugeno (T-S) fuzzy models. The main features of the proposed method are that i) it is provided that the sufficient conditions for stabilization of the discrete-time T-S fuzzy system in the sense of Lyapunov stability criterion, which is can be formulated in the linear matrix inequalities (LMIs); and ii) the stability properties of the trivial solution of the digital control system can be deduced from that of the solution of its discretized versions. An example is provided for showing the feasibility of the proposed method.