563 research outputs found

    A decision-based perspective for the design of methods for systems design

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    Organization of material, a definition of decision based design, a hierarchy of decision based design, the decision support problem technique, a conceptual model design that can be manufactured and maintained, meta-design, computer-based design, action learning, and the characteristics of decisions are among the topics covered

    Method for Producing Conductive or Insulating Feedthroughs in a Substrate

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    A method for producing feedthroughs in a substrate having a front and back surface, wherein the substrate either has a hole or absorbs radiation at a given wavelength. The method includes selecting and intimately bonding a sheet to the back surface of the substrate with an adhesive which is absorptive at the given wavelength. If the substrate has a hole, an exposed area of the sheet is illuminated with laser radiation at the given wavelength and at a power level sufficient to ablate a portion of the sheet behind the exposed area, thereby creating the feedthrough in the substrate. If the substrate has no hole, an area on the front surface of the substrate is illuminated with laser radiation at the given wavelength and at a power level sufficient to ablate a portion of the substrate and a portion of the sheet behind the area, thereby creating the feedthrough in the substrate. The sheet can then be removed from the substrate. Alternatively, if the sheet is conductive, the sheet can remain bonded to the substrate and can serve as a ground plane for the substrate. If the sheet is an insulator, the feedthrough is an insulated feedthrough and if the sheet is conductive, the feedthrough is a conductive feedthrough. This procedure can be extended to produce a two conductor feedthrough

    Simulation reduction using the Taguchi method

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    A large amount of engineering effort is consumed in conducting experiments to obtain information needed for making design decisions. Efficiency in generating such information is the key to meeting market windows, keeping development and manufacturing costs low, and having high-quality products. The principal focus of this project is to develop and implement applications of Taguchi's quality engineering techniques. In particular, we show how these techniques are applied to reduce the number of experiments for trajectory simulation of the LifeSat space vehicle. Orthogonal arrays are used to study many parameters simultaneously with a minimum of time and resources. Taguchi's signal to noise ratio is being employed to measure quality. A compromise Decision Support Problem and Robust Design are applied to demonstrate how quality is designed into a product in the early stages of designing

    A method for robust design in a coupled decision environment

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    The design of a connected engineered system requires numerous design decisions that influence one another. In a connected system that comprises numerous interacting decisions involving concurrency and hierarchy, accounting for interactions while also managing uncertainties, it is imperative to make robust decisions. In this article, we present a method for robust design using coupled decisions to identify design decisions that are relatively insensitive to uncertainties. To account for the influence among decisions, design decisions are modelled as coupled decisions. They are defined using three criteria: the types of decisions, the strength of interactions and the decision levels. In order to make robust decisions, robust design methods are classified based on sources of uncertainty, namely, Type I (noise factors), Type II (design variables) and Type III (function relationship between design variables and responses). The design of a one-stage reduction gearbox is used as a demonstration example. To illustrate the proposed method for robust design using coupled decisions, we present the simultaneous selection of gear material and gearbox geometry in a coupled decision environment while managing the uncertainties involved in designing gearboxes.Ye

    Disentangling the complexity of permafrost soil by using high resolution profiling of microbial community composition, key functions and respiration rates

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    Thawing permafrost can stimulate microbial activity, leading to faster decomposition of formerly preserved organic matter and CO2 release. Detailed knowledge about the vertical distribution of the responsible microbial community that is changing with increasing soil depth is limited. In this study, we determined the microbial community composition from cores sampled in a high Arctic heath at Svalbard, Norway; spanning from the active layer (AL) into the permafrost layer (PL). A special aim has been on identifying a layer of recently thawed soil, the transition zone (TZ), which might provide new insights into the fate of thawing permafrost. A unique sampling strategy allowed us to observe a diverse and gradually shifting microbial community in the AL, a Bacteroidetes dominated community in the TZ and throughout the PL, a community strongly dominated by a single Actinobacteria family (Intrasporangiaceae). The contrasting abundances of these two taxa caused a community difference of about 60%, just within 3 cm from TZ to PL. We incubated subsamples at about 5°C and measured highest CO2 production rates under aerobic incubations, yet contrasting for five different layers and correlating to the microbial community composition. This high resolution strategy provides new insights on how microbial communities are structured in permafrost and a better understanding of how they respond to thaw.publishedVersio

    Designing Platforms for Customizable Produces and Processes in Markets of Non-Uniform Demand

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    This definitive article is located at http://cer.sagepub.com. Copyright (2007) Sage Publications. DOI: 10.1177/1063293X07079328.The foremost difficulty in making the transition to mass customization is how to offer product variety affordably. The answer to this quandary lies in the successful management of modularity and commonality in the development of products and their production processes. While several platform design techniques have emerged as a means to offer modularity and commonality, they are limited by an inability to handle multiple modes of offering variety for multiple design specifications. The Product Platform Constructal Theory Method (PPCTM) is a technique that enables a designer to develop platforms for customizable products while handling issues of multiple levels of commonality, multiple product specifications, and the inherent trade-offs between platform extent and performance. The method is limited, however, by its inability to handle multiple design objectives and its reliance on the assumption that demand in the market is uniform for each product variant. The authors address these limitations in this paper by infusing the utility-based compromise Decision Support Problem and demand modeling techniques. The authors further augment the PPCTM by extending it use to a new domain: the design of process parameter platforms. The augmented approach is illustrated through a tutorial example: the design of a product and a process parameter platform for the realization of a line of customizable cantilever beams.National Science Foundation (Grants #DMI-0085136 and #DMI-9900259)

    CamAPS FX hybrid closed-loop with ultra-rapid lispro compared with standard lispro in adults with type 1 diabetes: a double-blind, randomized, crossover study.

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    INTRODUCTION To evaluate hybrid closed-loop with ultra-rapid insulin lispro (Lyumjev) compared with hybrid closed-loop with standard insulin lispro in adults with type 1 diabetes. MATERIALS AND METHODS In a single-center, double-blind, randomized, crossover study, 28 adults with type 1 diabetes (mean±SD: age 44.5±10.7, HbA1c 7.1±0.9% [54±10mmol/mol]) underwent two 8-week periods comparing hybrid closed-loop with ultra-rapid insulin lispro and hybrid closed-loop with standard insulin lispro in random order. CamAPS FX closed-loop system was used in both periods. RESULTS In an intention-to-treat analysis, the proportion of time sensor glucose was in target range (3.9 to 10mmol/L; primary endpoint) was greater with ultra-rapid lispro compared with standard insulin lispro (mean±SD: 78.7±9.8% vs. 76.2±9.6%; mean difference 2.5 percentage points [95%CI 0.8 to 4.2]; p=0.005). Mean sensor glucose was lower with ultra-rapid lispro compared with standard insulin lispro (7.9±0.8mmol/L vs. 8.1±0.9mmol/L; p=0.048). The proportion of time with sensor glucose <3.9mmol/L was similar between interventions (median [IQR] ultra-rapid lispro 2.3% [1.3-2.7%] vs. standard insulin lispro 2.1% [1.4-3.3%]; p=0.33). No severe hypoglycemia or ketoacidosis occurred. CONCLUSIONS The use of ultra-rapid lispro with CamAPS FX hybrid closed-loop increases time in range and reduces mean glucose with no difference in hypoglycemia compared with standard insulin lispro in adults with type 1 diabetes
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