The Design of Human–Machine Interface for Accident Support in Nuclear Power Plants

As feedback from Three Mile Island No. 2, a large amount of human–machine interface (HMI) design has been proposed to support operators during accidents by presenting information on plant status, some of which is implemented in commercial nuclear power plants (NPPs). However, it has not yet been discussed what role HMI should play under conditions where operators must take action as instructed under emergency operating procedure. Regarding this principal issue, an HMI design is proposed together with specific screen images. The advantage of this design is based on the involvement of an ex-operator in NPP in this paper. The participation of users in the design of HMI has been rare. Accordingly the proposed HMI is comprehensive for average operators and is expected to be acceptable for future implementation in commercial NPPs. The effectiveness of the proposed HMI has been examined in a small experiment.     

The Kalman–Yakubovich–Popov inequality for differential-algebraic systems: Existence of nonpositive solutions

The Kalman–Yakubovich–Popov lemma is a central result in systems and control theory which relates the positive semidefiniteness of a Popov function on the imaginary axis to the solvability of a linear matrix inequality. In this paper we prove sufficient conditions for the existence of a nonpositive solution of this inequality for differential-algebraic systems. Our conditions are given in terms of positivity of a modified Popov function in the right complex half-plane. Our results also apply to non-controllable systems. Consequences of our results are bounded real and positive real lemmas for differential-algebraic systems.     

The Depletion–Power–Integration–Latency (DPIL) model of spaced and massed repetition

Although several models have been suggested in the literature to describe the relationship between learning and forgetting, this relationship is still not fully understood. This paper proposes the Depletion–Power–Integration–Latency (DPIL) model, which assumes that performing a task repetitively depletes the available encoding resources for that task. The DPIL model fitted five empirical datasets well, reflecting different procedural/episodic learning settings, experimental paradigms (massed/spaced repetition, study time), tests (accuracy, latency), and retention intervals. The model was also fitted to empirical data collected from a quality inspection station at an industrial firm. The DPIL model has the advantage of predicting the length of the final break (interruption) that optimizes performance. This finding is important as it has many industrial engineering applications. The numerical results in this paper show that performance improves as the length of each break preceding the final break increases. This is consistent with empirical findings that moderately short breaks are optimal for performance.     

Model predictive control of a DC–DC converter for battery emulation

A battery emulator is used instead of a real traction battery to supply an electric motor inverter on a test bed for hybrid and electric powertrains under deterministic conditions. The use of virtual battery models eliminates the need for expensive battery prototypes. Virtual battery properties such as chemistry, state of charge or state of health can be changed instantly. However, the control of a battery emulator is a challenging problem. Very fast reference tracking is required for battery impedance emulation but motor inverters act as constant power loads that have a negative influence on the tracking performance and can even lead to instability. In this paper an MPC strategy is proposed for solving this problem. Scheduling of local controllers is utilized in order to handle the nonlinear and destabilizing load. Furthermore, a fast algorithm is presented that allows real-time MPC subject to input and output constraints. Experimental results obtained with a battery emulator supplying an electric drive inverter demonstrate the performance of the stabilizing controller.     

Reprint of “The Kalman–Yakubovich–Popov inequality for differential-algebraic systems: Existence of nonpositive solutions”

The Kalman–Yakubovich–Popov lemma is a central result in systems and control theory which relates the positive semidefiniteness of a Popov function on the imaginary axis to the solvability of a linear matrix inequality. In this paper we prove sufficient conditions for the existence of a nonpositive solution of this inequality for differential-algebraic systems. Our conditions are given in terms of positivity of a modified Popov function in the right complex half-plane. Our results also apply to non-controllable systems. Consequences of our results are bounded real and positive real lemmas for differential-algebraic systems.     

Assumption–Commitment Support for CSP Model Checking

We present a simple formulation of Assumption–Commitment reasoning using CSP (Communicating Sequential Processes). An assumption–commitment style property of a process SYS takes the form $COM \sqsubseteq SYS \| ASS $ , for ‘assumption’ and ‘commitment’ processes ASS and COM. We describe proof rules that allow derivation of assumption–commitment style properties of a composite system from such properties of its components, given appropriate side conditions. Most of the rules have a superficially appealing ‘homomorphic’ quality: the overall assumption and commitment processes are composed similarly to the overall system. We also give a ‘non-homomorphic’ rule that corresponds quite well to classical assumption–commitment rules. Antecedants and side conditions can be expressed as refinements and checked separately by the refinement-style model checker FDR. Examples illustrate application of our theory.     

The Human–Artifact Model: An Activity Theoretical Approach to Artifact Ecologies

Although devices of all shapes and sizes currently dominate the technological landscape, human–computer interaction (HCI) as a field is not yet theoretically equipped to match this reality. In this article we develop the human–artifact model, which has its roots in activity theoretical HCI. By reinterpreting the activity theoretical foundation, we present a framework that helps addressing the analysis of individual interactive artifacts while embracing that they are part of a larger ecology of artifacts. We show how the human–artifact model helps structuring the understanding of an artifact's action-possibilities in relation to the artifact ecology surrounding it. Essential to the model is that it provides four interconnected levels of analysis and addresses the possibilities and problems at these four levels.

Artifacts and their use are constantly developing, and we address development in, and of, use. The framework needs to support such development through concepts and methods. This leads to a methodological approach that focuses on new artifacts to supplement and substitute existing artifacts. Through a design case, we develop the methodological approach and illustrate how the human–artifact model can be applied to analyze present artifacts and to design future ones. The model is used to structure such analysis and to reason about findings while providing leverage from activity theoretical insights on mediation, dialectics, and levels of activity.     

A Linear–Programming Method for the Combinatorial Grouping of an Incomplete Power Set

Abstract

The Combinatorial Grouping Problem is defined as the general problem of computing a set of boolean bounds (GLB, LUB) for an incomplete power set P(U)so that a system of lattice-theoretic filter-ideal intersections (GLB, LUB) results which optimizes a cost function defined on the parent set U.

The problem arises as a mathematical formulation of the Group-Technology Problem of Industry. A system of independent Production Cells is required which provides the manufacturing capacity for the commercial life of an industrial product. A group of components is matched with a group of facilities so that there is a maximal degree of scheduling flexibility and a minimal cost of manufacture.

A Set-Partitioning Algorithm has been developed which may be adapted to solve a wide class of related combinatorial problems.     

Bus-Switch Encoding for Power Optimization of Address Bus

This paper presents a novel encoding technique to minimize the switch activities on the highly capacitive memory address bus so as to reduce power dissipation of bus. This technique is based on the temporal locality and spatial locality of instruction address. The experimental results based on an instruction set simulator and SPEC2000 benchmarks show that the presented encoding technique can reduce signal transitions on the address bus by 83.8%, and the actual overhead of the encoder circuit is estimated after encoder has been designed and synthesized with 0.18-μm CMOS technology. The results show that our technique well outperforms specialized low-power encoding schemes presented in the past.     

The Probability Model of the Multi-valued Shrinking Generator

This paper constructs the probability model of the general multi-valued shrinking generator, which takes two-valued key stream shrinking generator and generalized shrinking generator as special cases. It discusses the probability properties of their output sequences, and gets the formulae of the coincidence of the output sequences with the original input sequences in particular. It also analyzes the properties and success and failure of this kind of generator in view of probability theory.     

Model predictive control for uncertain max–min-plus-scaling systems

In this paper we extend the classical min–max model predictive control framework to a class of uncertain discrete event systems that can be modelled using the operations maximization, minimization, addition and scalar multiplication, and that we call max–min-plus-scaling (MMPS) systems. Provided that the stage cost is an MMPS expression and considering only linear input constraints then the open-loop min–max model predictive control problem for MMPS systems can be transformed into a sequence of linear programming problems. Hence, the min–max model predictive control problem for MMPS systems can be solved efficiently, despite the fact that the system is non-linear. A min–max feedback model predictive control approach using disturbance feedback policies is also presented, which leads to improved performance compared to the open-loop approach.     

A Substitution Based Model for the Implementation of PROLOG——The Design and Implementation of LPROLOG

Since PROLOG has been chosen as the Fifth Generation Computer's Kernal Language,it ispresently one of the hottest topics among computer scientists all over the world.Recently,theimplementation technique and the application of PROLOG have been developed rapidly.In thispaper,a new implementation scheme for PROLOG is proposed.The scheme is based on thesubstitution of instantiated veriable values.It has many advantages,such as a higher runningspeed,less main memory requirement,and easier to be implemented.The scheme has beenimplemented by the authors on IBM4341.     

Multigrid Methods for a Mixed Finite Element Method of the Darcy–Forchheimer Model

An efficient nonlinear multigrid method for a mixed finite element method of the Darcy–Forchheimer model is constructed in this paper. A Peaceman–Rachford type iteration is used as a smoother to decouple the nonlinearity from the divergence constraint. The nonlinear equation can be solved element-wise with a closed formulae. The linear saddle point system for the constraint is reduced into a symmetric positive definite system of Poisson type. Furthermore an empirical choice of the parameter used in the splitting is proposed and the resulting multigrid method is robust to the so-called Forchheimer number which controls the strength of the nonlinearity. By comparing the number of iterations and CPU time of different solvers in several numerical experiments, our multigrid method is shown to convergent with a rate independent of the mesh size and the Forchheimer number and with a nearly linear computational cost.     

Model organism proteomics as a tool for the study of host–microbiome interactions

All organisms live in constant contact with the microbial world. In recent years it has become evident that these microbial communities are not only responsible for the development of certain diseases, but are also an indispensable factor for homeostasis. The inherent complexity of meta-organisms hampers a straightforward elucidation of the molecular processes regulating the interactions of the host and its microbiome, as well as the influence of exogenic factors, for example, nutrition. Modern approaches such as meta-proteomics are now capable of deciphering the major processes in microbial communities, but the complete analysis of their interactions with their host is still in its infancy. In order to get easier access, the study of nonmammalian model organisms bears great potential. These organisms provide advantages such as reduced complexity, ease of cultivation in great numbers, and amenity to a range of genetic and biochemical manipulations. We highlight the potentials provided by model organism proteomics for the study of host–microbiome interactions and outline major challenges and demands for technological improvements that will be necessary for the understanding of the manifold interactions within meta-organisms.     

The input–output version of the Aizerman–Myshkis problem for retarded systems

Non-linear retarded systems are considered. Conditions for the input-output stability are derived. They are formulated in terms of the zeros of the corresponding quasi-polynomials. In addition, it is proved that retarded systems with positive impulse (Green) functions satisfy the Aizerman-Myshkis conjecture in the input-output version.     

“NTT's Joint Utilization Tests of Multimedia Communications”--Utilization Tests for CATV and VOD over FTTH

NTT is carrying out Utilization Tests for CATV Video Transmissions that provide CATV video transmissions, Video-on-demand (VOD) and ISDN services on an integrated basis to participating subscribers. In these tests, optical fibers are installed under the Fiber-to-the-Home (FTTH) concept in three trial areas, each having about 300 subscribers, and two types of transmission systems are used: FDM-PON and ATM-PON. The trial is scheduled to finish at the end of March, 1997.