Incorporating just-in-time into a decision support system environment

In this paper, a Decision Support System is proposed for a Just-In-Time production system. The Decision Support System includes three components: database, model base, and interface. The database contains the predefined parameters together with the data generated for the considered Just-In-Time production system. In the model base, both deterministic and stochastic aspects of the system are considered. The deterministic system is examined by constructing a linear programming model whereas simulation is used as a tool for the stochastic system. Furthermore, a sensitivity analysis is performed on the Just-In-Time production system with the help of the Decision Support System environment for the unit load size changes under different demand patterns by using the alternative solutions obtained from the model base. © 1991

General behavior of pull production systems: the allocation problems

The design of tandem production systems has been well studied in the literature with the primary focus being on how to improve their efficiency. Considering the large costs associated, a slight improvement in efficiency can lead to very significant savings over its life. Division of work and allocation of buffer capacities between workstations are two critical design problems that have attracted the attention of many researchers. In this study, first an understanding into how the system works is to be provided. Except for the integration of two allocation problems, the basic model utilized here is essentially the same as the previous studies. Theoretical results that characterize the dynamics of these systems may also provide some heuristic support in the analysis of large-scale pull production systems

Analytical loading models in flexible manufacturing systems

It would be difficult to efficiently implement a manufacturing system without solving its design and operational problems. Based on this framework, a system configuration and tooling problem is modeled. The model turns out to be a large mixed integer linear program, so that some alternative optimal seeking and heuristic techniques are used to solve the model for constructing a flow line structured Flexible Manufacturing System. As a result, it may be possible to construct flexible, efficient, simple and easily controllable manufacturing systems. © 1993

5-Bromo-3-(indan-1-yl­oxy)pyridin-2-amine

The title compound, C14H13BrN2O, was obtained by reaction of indan-1-yl methane­sulfonate with 2-amino-5-bromo­pyridin-3-ol in the presence of caesium carbonate. The indane ring system is approximately planar [all but one of the C atoms are coplanar within 0.03 Å, the latter atom being displaced by 0.206 (2) Å from the mean plane through the remaining atoms] and forms a dihedral angle of 58.41 (4)° with the pyridine ring. In the crystal, centrosymmetrically related mol­ecules are linked into dimers by N—H⋯N hydrogen bonds

The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst

We report on quasi-simultaneous observations from radio to X-ray frequencies of the neutron star X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the observations show radio to millimetre spectra consistent with emission from a jet, with a spectral break from optically thick to optically thin synchrotron emission that decreases from ~100 GHz to <5.5 GHz during the transition from a hard to a soft accretion state. The 5.5 GHz radio flux density as the source reaches the soft state, 0.82 ± 0.03 mJy, is the highest recorded to date for this source. During the decay of the outburst, the jet spectral break is detected again at a frequency of ~30-100 GHz. The flux density is 0.75 ± 0.03 mJy at 97.5 GHz at this stage. This is the first time that a change in the frequency of the jet break of a neutron star X-ray binary has been measured, indicating that the processes at play in black holes are also present in neutron stars, supporting the idea that the internal properties of the jet rely most critically on the conditions of the accretion disc and corona around the compact object, rather than the black hole mass or spin or the neutron star surface or magnetic field

Tackling Biased Baselines in the Risk-Sensitive Evaluation of Retrieval Systems

Abstract. The aim of optimising information retrieval (IR) systems using a risk-sensitive evaluation methodology is to minimise the risk of performing any par-ticular topic less effectively than a given baseline system. Baseline systems in this context determine the reference effectiveness for topics, relative to which the effectiveness of a given IR system in minimising the risk will be measured. How-ever, the comparative risk-sensitive evaluation of a set of diverse IR systems – as attempted by the TREC 2013 Web track – is challenging, as the different systems under evaluation may be based upon a variety of different (base) retrieval models, such as learning to rank or language models. Hence, a question arises about how to properly measure the risk exhibited by each system. In this paper, we argue that no model of information retrieval alone is representative enough in this respect to be a true reference for the models available in the current state-of-the-art, and demonstrate, using the TREC 2012 Web track data, that as the baseline system changes, the resulting risk-based ranking of the systems changes significantly. In-stead of using a particular system’s effectiveness as the reference effectiveness for topics, we propose several remedies including the use of mean within-topic sys-tem effectiveness as a baseline, which is shown to enable unbiased measurements of the risk-sensitive effectiveness of IR systems.

4,5-Bis(2,4-di-tert-butyl­phen­oxy)phthalonitrile

In the title compound, C36H44N2O2, the dihedral angles between the phthalonitrile ring and the two di-tert-butyl­benzene rings are 68.134 (8) and 70.637 (11)°. The two nitrile groups are almost coplanar with the phthalonitrile ring except for one of the N atoms which deviates from the plane by 0.125 (4) Å. One of the tert-butyl groups is disordered over two orientations, with refined occupancies of 0.814 (6) and 0.186 (6). Intra­molecular C—H⋯O inter­actions stabilize the molecular structure. The crystal packing is stabilized by inter­molecular C—H⋯N inter­actions

Modelling spectral and timing properties of accreting black holes: the hybrid hot flow paradigm

The general picture that emerged by the end of 1990s from a large set of optical and X-ray, spectral and timing data was that the X-rays are produced in the innermost hot part of the accretion flow, while the optical/infrared (OIR) emission is mainly produced by the irradiated outer thin accretion disc. Recent multiwavelength observations of Galactic black hole transients show that the situation is not so simple. Fast variability in the OIR band, OIR excesses above the thermal emission and a complicated interplay between the X-ray and the OIR light curves imply that the OIR emitting region is much more compact. One of the popular hypotheses is that the jet contributes to the OIR emission and even is responsible for the bulk of the X-rays. However, this scenario is largely ad hoc and is in contradiction with many previously established facts. Alternatively, the hot accretion flow, known to be consistent with the X-ray spectral and timing data, is also a viable candidate to produce the OIR radiation. The hot-flow scenario naturally explains the power-law like OIR spectra, fast OIR variability and its complex relation to the X-rays if the hot flow contains non-thermal electrons (even in energetically negligible quantities), which are required by the presence of the MeV tail in Cyg X-1. The presence of non-thermal electrons also lowers the equilibrium electron temperature in the hot flow model to <100 keV, making it more consistent with observations. Here we argue that any viable model should simultaneously explain a large set of spectral and timing data and show that the hybrid (thermal/non-thermal) hot flow model satisfies most of the constraints.Comment: 26 pages, 13 figures. To be published in the Space Science Reviews and as hard cover in the Space Sciences Series of ISSI - The Physics of Accretion on to Black Holes (Springer Publisher