VCSEL-array-based angle-multiplexed optoelectronic crossbar interconnects

A large crossbar switch, which is a desirable building block for any low-latency interconnect network, is difficult to implement because of many practical problems associated with digital electronics. We propose a new method for implementing a large optoelectronic crossbar interconnect to take advantage of a unique principle of optics. Based on an emerging vertical-cavity surface-emitting laser (VCSEL) technology, a passive angle-multiplexed beam-steering architecture is proposed as a key component of the optoelectronic crossbar. Various optical system parameters are evaluated. Because there is no optical fan-out power loss, the interconnect capacity of the proposed system is determined by the diffraction-limited receiver power cutoff, and therefore interconnection of more than 1000 nodes with a per node bandwidth of 1 GHz is possible with today's technology. A 64-element VCSEL-array-based proof-of-principle optical system for studying the interconnect scalability has been built. Details of the features of the proposed system, its advantages and limitations, demonstration experimental results, and their analyses are presented.     

Actin-titin interaction in cardiac myofibrils: probing a physiological role

The high stiffness of relaxed cardiac myofibrils is explainable mainly by the expression of a short-length titin (connectin), the giant elastic protein of the vertebrate myofibrillar cytoskeleton. However, additional molecular features could account for this high stiffness, such as interaction between titin and actin, which has previously been reported in vitro. To probe this finding for a possible physiological significance, isolated myofibrils from rat heart were subjected to selective removal of actin filaments by a calcium-independent gelsolin fragment, and the "passive" stiffness of the specimens was recorded. Upon actin extraction, stiffness decreased by nearly 60%, and to a similar degree after high-salt extraction of thick filaments. Thus actin-titin association indeed contributes to the stiffness of resting cardiac muscle. To identify possible sites of association, we employed a combination of different techniques. Immunofluorescence microscopy revealed that actin extraction increased the extensibility of the previously stiff Z-disc-flanking titin region. Actin-titin interaction within this region was confirmed in in vitro cosedimentation assays, in which multimodule recombinant titin fragments were tested for their ability to interact with F-actin. By contrast, such assays showed no actin-titin-binding propensity for sarcomeric regions outside the Z-disc comb. Accordingly, the results of mechanical measurements demonstrated that competition with native titin by recombinant titin fragments from Z-disc-remote, I-band or A-band regions did not affect passive myofibril stiffness. These results indicate that it is actin-titin association near the Z-disc, but not along the remainder of the sarcomere, that helps to anchor the titin molecule at its N-terminus and maintain a high stiffness of the relaxed cardiac myofibril.     

A Geometric Strategy Algorithm for Orthogonal Projection onto a Parametric Surface

Journal of Computer Science and Technology - In this paper, we investigate how to compute the minimum distance between a point and a parametric surface, and then to return the nearest point (foot...     

Conceptualizing development in information and communication technology for development (ICT4D)

ABSTRACT

ICT4D research is faced with the challenge of rapidly changing technologies and increasingly complex social dynamics and development processes. We argue that ICT4D research requires a more acute sense of where our research is situated within a broader picture of development, e.g. with a better understanding of development processes, their ideological nature, the power structures and driving forces, and the mechanisms through which ICTs may be embedded in and shape these processes. Such a reflexivity is crucial not least in justifying our claims of contribution, but also in understanding the implications and potential impact of our research and practice. This editorial seeks to explore key conceptual components in ICT4D and their relationships, including dimensions of development, perspectives of development, conceptions of artefacts, and theory of change. A tentative conceptual schema is presented that connects these conceptual components.     

Strategic ramp-up planning in automotive production networks

In many industries, the frequency of production ramp-ups has increased due to shorter product life cycles and increased product variety. Production often takes place at globally dispersed facilities for customers in multiple markets, for example, in the automotive industry. Therefore, ramp-up planning must be carried out for a network. The planning problem at hand is to simultaneously optimise the allocation of products of a common product platform to plants, the timing of ramp-ups and ramp-downs, ramp-up duration and shape of capacity and production and transportation volumes with respect to the net present value of the profit. We develop a hierarchical planning framework and place strategic ramp-up planning therein. We provide a mixed integer programming model for this planning problem. Following the example of a German car manufacturer in the premium segment, we conduct a numerical analysis to obtain insights into optimal ramp-up and ramp-down decisions. The results show that it could be beneficial to use both steep and flat ramp-up curves. The impact of flexibility in the choice of ramp-up slots and the number of ramp-up curves provided on the objective value is substantial. The strategic ramp-up planning model outperforms sequential planning approaches.     

An Improved Supplier Driven Packaging Design and Development Method for Supply Chain Efficiency

Packaging and the role it plays in supply chain efficiency are overlooked in most design and development research. An opportunity exists to meet the needs of supply chains to increase efficiency. This research presents three propositions on how to reduce the gap between supply chain needs and satisfaction in interaction with the product and packaging system. It also proposes a supply chain focused packaging design and development method to better satisfy supply chain needs placed on packaging. An extensive literature review was conducted, and a Tetra Pak derived case study was developed. The propositions were formulated and became the basis for improving Tetra Pak's existing packaging design and development method by better integrating supply chain needs. This was accomplished by using an expanded operational life cycle perspective that includes the entire supply chain. The resulting supply chain focused packaging design, and development method enables improved supply chain efficiency while considering the product, the processes and cost. Copyright © 2016 John Wiley & Sons, Ltd.     

Elucidating the Indirect Contributions of Packaging to Sustainable Development: A Terminology of Packaging Functions and Features

Packaging has great potential to contribute to sustainable development through its functions. Previous research has indicated a need for increased knowledge among consumers, suppliers, authorities and media of how packaging functions and features influence sustainable development. Previous research also shows the need for a common terminology of packaging functions and features in order to facilitate and improve communication and understanding in development and decision processes. This conceptual paper sets out to identify, collect, analyse and systemize packaging functions and features and evaluate them based on their indirect contributions to sustainable development. The systemized functions and features are expressed in generic terminology. Three clusters of packaging functions were identified from the literature: protect, facilitate handling and communicate. Nineteen packaging features were also identified. They were grouped under the three functions and elaborated based on their indirect contributions to the environmental, social and economic dimensions of sustainable development. Fourteen potential positive indirect effects were identified including decreased product waste, reduced risk for human health hazards, increased handling and transport efficiency. Decreased product waste was generated by 13 of the features and was thus the most frequently appearing. Reducing waste is thereby indicated to be a manifold matter, but also one of great potential. The proposed terminology can contribute to an increased understanding of how packaging can actually contribute to sustainable development. In a theoretical context, this paper attempts to complement earlier work in sustainable packaging development by its emphasis on the indirect contributions of packaging to sustainable development.     

Influence of polymer molecular weight on the solid-state structure of PEG/monoolein mixtures

The polar lipid monoolein (MO) and poly(ethylene glycol), PEG, of different molar mass (1500, 4000 and 8000) were melted, mixed and left to solidify at room temperature. Analysis of the solid mixtures by differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) revealed that a phase separation occurs when MO is present in sufficient amounts. The molecular weight of the polymer determines the amount of MO that has to be added before a separate MO phase can be detected. To further understand this behaviour, the folding of the polymers and the thickness of the amorphous domains within the lamellar structure of PEG were determined by calculation of the one-dimensional correlation function from the experimental SAXS data. It revealed that the presence of MO makes the crystalline domains of PEG 1500, which crystallizes unfolded, increase at the expense of the amorphous domains. PEG 4000 and PEG 8000 obtain a higher degree of folding when the MO content in the mixtures increases. Furthermore, a second form of MO was detected when it phase separated from PEG 1500 and 4000. This behaviour was argued to be due to the secondary crystallization of the PEGs.