Asim: a performance model framework

The longevity and usefulness of a microprocessor performance model has historically depended on the model writer's skills and discipline. However, at Compaq the models became extremely complex and unmanageable because designers lacked a structured way to develop them. To cope with these complexities, Compaq researchers began developing Asim in late 1998 to allow model writers to faithfully represent the detailed timing of complex modern machines and effectively manage the large software projects needed to model such machines. Asim addresses these needs by providing a modular and reusable framework for creating many models. The framework's modularity helps break down the performance-modeling problem into individual pieces that can be modeled separately, while its reusability allows using a software component repeatedly in different contexts     

Long-term energy projections for the U.S.A.

This report starts by surveying a series of papers that are representative of recent U.S. work on national and international energy policy. Among professional analysts, there are the beginnings of a consensus on energy demand projections and on energy-economy interactions. Moreover, it is recognized that conservation policies will be difficult to implement unless domestic prices are raised to the international level. The paper includes a series of long-term energy projections based upon ETA-MACRO. This model allows for: energy-economy interactions, cost-effective conservation and interfuel substitution between electric and nonelectric energy. the calculations are based upon a somewhat less optimistic view of synthetic fuels and of ‘backstop’ technologies than appear in the Carter Administration's recent proposals. With synfuels, backstops and nuclear energy—and with realistically reduced projections of demand growth—there is a reasonable prospect that the U.S. could meet an international commitment to limit oil and gas imports. U.S. import reductions could be achieved directly through the market price mechanism, without tariffs or quota limitations. For this to happen, however, the international price of oil would have to be doubled (in constant dollar terms) by the year 2000. A policy of gradual OPEC oil price increases would facilitate the transition away from oil, and could serve the long-run interests of both the producing and consuming nations.     

A genetic algorithm approach to the multiple machine tool selection problem

A number of earlier researches have emphasized the on-the-job scheduling problems that occur with a single flexible machine. Two solutions to the problem have generally been considered; namely minimization of tool switches and minimization of tool switching instances. Methods used to solve the problems have included KTNS heuristic, dual-based relaxation heuristic, and non-LP-based branch-and-bound methods. However, scant literature has considered the case of job scheduling on multiple parallel machines which invokes another problem involving machine assignment. This paper addresses the problem of job scheduling and machine assignment on a flexible machining workstation (FMW) equipped with multiple parallel machines in a tool-sharing environment. Under these circumstances, the authors have attempted to model the problem with the objective of simultaneously minimizing both the number of tool switches and the number of tool switching instances. Furthermore, a set of realistic constraints has been included in the investigation. A novel genetic algorithm (GA) heuristic has been developed to solve the problem, and performance results show that GA is an appropriate solution.     

Nonmulberry Silk Based Ink for Fabricating Mechanically Robust Cardiac Patches and Endothelialized Myocardium‐on‐a‐Chip Application

Bioprinting holds great promise toward engineering functional cardiac tissue constructs for regenerative medicine and as drug test models. However, it is highly limited by the choice of inks that require maintaining a balance between the structure and functional properties associated with the cardiac tissue. In this regard, a novel and mechanically robust biomaterial‐ink based on nonmulberry silk fibroin protein is developed. The silk‐based ink demonstrates suitable mechanical properties required in terms of elasticity and stiffness (≈40 kPa) for developing clinically relevant cardiac tissue constructs. The ink allows the fabrication of stable anisotropic scaffolds using a dual crosslinking method, which are able to support formation of aligned sarcomeres, high expression of gap junction proteins as connexin‐43, and maintain synchronously beating of cardiomyocytes. The printed constructs are found to be nonimmunogenic in vitro and in vivo. Furthermore, delving into an innovative method for fabricating a vascularized myocardial tissue‐on‐a‐chip, the silk‐based ink is used as supporting hydrogel for encapsulating human induced pluripotent stem cell derived cardiac spheroids (hiPSC‐CSs) and creating perfusable vascularized channels via an embedded bioprinting technique. The ability is confirmed of silk‐based supporting hydrogel toward maturation and viability of hiPSC‐CSs and endothelial cells, and for applications in evaluating drug toxicity.     

Web warehouse – a new web information fusion tool for web mining

In this study, we introduce a web information fusion tool – web warehouse, which is suitable for web mining and knowledge discovery. To formulate a web warehouse, a four-layer web warehouse architecture for decision support is firstly proposed. According to the layered web warehouse framework architecture, an extraction–fusion–mapping–loading (EFML) process model for web warehouse construction is then constructed. In the web warehouse process model, a series of web services including wrapper service, mediation service, ontology service and mapping service are used. Particularly, two kinds of mediators are introduced to fuse the heterogeneous web information. Finally, a simple case study is presented to illustrate the construction process of web warehouse.     

A decision analysis of the U.S. breeder reactor program

Past modelling efforts have failed to reach a consensus on breeder R & D strategy. These failures have led some to question the usefulness of benefit-cost analysis for a problem as complex and as politicized as this one has become. Our paper examines some of the major weaknesses of past benefit-cost analyses and then reformulates the breeder investment decision in a decision tree framework. Decision analysis is used to evaluate alternative R & D strategies that range from accelerating the current effort to abandoning the entire program.

Breeder benefits are assessed through ETA-MACRO, a model of interactions between the energy sector and the rest of the U.S. economy. A dynamic non-linear optimization procedure is used to examine how breeder timing could depend upon alternative assumptions with respect to:

1. (a) uranium supply,

2. (b) energy demand growth,

3. (c) environmental constraints upon coal and shale oil production, and

4. (d) the availability of alternative energy sources.

Subjective probabilities have been estimated through a Delphi questionnaire on the critical uncertainties. Each individual's responses have been used independently to calculate an optimal strategy. A fairly simple rule-of-thumb has emerged from this experiment. If a respondent believes that the probability of positive benefits (P) exceeds 0.03, there are positive expected dollar benefits from any breeder development program. If P is less than 0.03, however, the expected economic benefits of such a program would be negative. The costs of the R & D program would then exceed their actuarial value.     

White Organic LED with a Luminous Efficacy Exceeding 100 lm W−1 without Light Out‐Coupling Enhancement Techniques

Luminous efficacy (LE), which is given by the ratio of luminous flux to power, is commonly used to measure the power consumption of a light source. Unfortunately, the LE of white organic light‐emitting diodes (OLEDs) still lags behind those of inorganic LED for practically used (>100 lm W^?1). In this paper, an ultraefficient white OLED is discussed based on a newly designed thermally activated delayed fluorescent exciplex host. The resulting white OLED delivers an unusually high forward‐viewing LE of 105.0 lm W^?1 and external quantum efficiency (EQE) η_ext of ≈30% (without using any optical out‐coupling techniques). As far as it is known, specifically, these efficiencies are the highest values among the published white OLEDs to date. Two‐color warm white emission is realized with Commission International de I'Eclairage coordinates of (0.40, 0.48) at a brightness of 1000 cd m^?2. Furthermore, the well‐matched energy alignment endows the device with an extremely low turn‐on voltage (≈2.5 V). Such high efficiencies and excellent device performance should benefit from the advantages of exciplex material solely used as the host. Therefore, this study anticipates that the findings have great potential to boost the LE of OLEDs, and more importantly, fulfill the power efficacy requirement for lighting applications.     

A Hierarchical Z‑Scheme α‐Fe2O3/g‐C3N4 Hybrid for Enhanced Photocatalytic CO2 Reduction

The challenge in the artificial photosynthesis of fossil resources from CO₂ by utilizing solar energy is to achieve stable photocatalysts with effective CO₂ adsorption capacity and high charge‐separation efficiency. A hierarchical direct Z‐scheme system consisting of urchin‐like hematite and carbon nitride provides an enhanced photocatalytic activity of reduction of CO₂ to CO, yielding a CO evolution rate of 27.2 µmol g^?1 h^?1 without cocatalyst and sacrifice reagent, which is >2.2 times higher than that produced by g‐C₃N₄ alone (10.3 µmol g^?1 h^?1). The enhanced photocatalytic activity of the Z‐scheme hybrid material can be ascribed to its unique characteristics to accelerate the reduction process, including: (i) 3D hierarchical structure of urchin‐like hematite and preferable basic sites which promotes the CO₂ adsorption, and (ii) the unique Z‐scheme feature efficiently promotes the separation of the electron–hole pairs and enhances the reducibility of electrons in the conduction band of the g‐C₃N₄. The origin of such an obvious advantage of the hierarchical Z‐scheme is not only explained based on the experimental data but also investigated by modeling CO₂ adsorption and CO adsorption on the three different atomic‐scale surfaces via density functional theory calculation. The study creates new opportunities for hierarchical hematite and other metal‐oxide‐based Z‐scheme system for solar fuel generation.     

Optimal inventory control policy and supply chain coordination problem with carbon footprint constraints

Carbon footprint constraints exert pressure on supply chains to reexamine decisions. In this paper, we consider carbon transfer cost and carbon holding cost in a supply chain. A multiperiod dynamic programming model with carbon footprint constraints is presented to investigate the impact of carbon transfer cost and carbon holding cost on inventory control policy as well as the supply chain coordination problem. A two‐control limit inventory control policy is proved to be optimal and a contract with wholesale price, subsidy, and fixed setup cost is verified analytically to coordinate the supply chain. Finally, a numerical study is conducted to reveal managerial insights. We find that when the supply chain is coordinated, the chain's profit is more sensitive to carbon transfer cost while inventory level is more sensitive to carbon holding cost. Additionally, because of the complexity of the coordinated contract, when it is not easy to coordinate the supply chain, it is better to keep the values of wholesale price, subsidy, and fixed setup cost below the corresponding values for the coordinated supply chain.