Collaborative technologies in knowledge telework: an exploratory study

Abstract.  Knowledge workers in distributed work environments require substantial communication with colleagues and supervisors to perform their work activities, and collaborative technologies, like groupware, continue to improve the potential for such communication. This study investigates how an improvement in collaborative technology among a group of knowledge teleworkers impacts their communication patterns. The study focuses on one communication-based work process: knowledge sharing. The research involves a 6-month exploratory longitudinal case study of a group of teleworkers where a new groupware technology was implemented. The results indicate that while there are fewer instances of communication among group members after the technology is implemented, communication becomes more centralized around the district manager. These results suggest that increased collaborative technologies result in an adjustment between explicit and tacit knowledge sharing, as the availability of a centralized and updateable database reduces workgroup communications. However, consistent with structuration theory, telework group members do use communication technologies to address their most apparent needs and concerns. Other potential explanations and implications of these findings are discussed.     

Ultra-thin films and multigate devices architectures for future CMOS scaling

The nanoelectronics industry is facing historical challenges to scale down CMOS devices to meet demands for low voltage, low power, high performance and increased functionality. Using new materials and devices architectures is necessary. HiK gate dielectrics and metal gates have been introduced and have shown their ability to reduce power consumption. Fully depleted ultra-thin SOI devices are a good alternative to bulk for low power applications. Multigate devices are the current goal in device architecture...     

A UML-based pattern specification technique

Informally described design patterns are useful for communicating proven solutions for recurring design problems to developers, but they cannot be used as compliance points against which solutions that claim to conform to the patterns are checked. Pattern specification languages that utilize mathematical notation provide the needed formality, but often at the expense of usability. We present a rigorous and practical technique for specifying pattern solutions expressed in the unified modeling language (UML). The specification technique paves the way for the development of tools that support rigorous application of design patterns to UML design models. The technique has been used to create specifications of solutions for several popular design patterns. We illustrate the use of the technique by specifying observer and visitor pattern solutions.     

Study on SCS-6/Ti-6A1-4V Composite

COMPARED WITH traditional titanium alloys,titanium matrix composites exhibit much improvedmechanical properties,in terms of specific strengthsand stiffness at ambient and elevated temperatures.From1970's on,much attention has been put ontitanium matrix composite[1~31.Titanium matrixcomposites are divided into two categories:fiber-reinforced and particle reinforced.These twokinds of composites have their own advantageous.AsTSM Company solve the interface interaction betweenSCS-6fiber an…     

A mechanistic model of small intestinal starch digestion and glucose uptake in the cow

The high contribution of postruminal starch digestion (up to 50%) to total-tract starch digestion on energy-dense, starch-rich diets demands that limitations to small intestinal starch digestion be identified. A mechanistic model of the small intestine was described and evaluated with regard to its ability to simulate observations from abomasal carbohydrate infusions in the dairy cow. The 7 state variables represent starch, oligosaccharide, glucose, and pancreatic amylase in the intestinal lumen, oligosaccharide and glucose in the unstirred water layer at the intestinal wall, and intracellular glucose of the enterocyte. Enzymatic hydrolysis of starch was modeled as a 2-stage process involving the activity of pancreatic amylase in the lumen and of oligosaccharidase at the brush border of the enterocyte confined within the unstirred water layer. The Na⁺-dependent glucose transport into the enterocyte was represented along with a facilitative glucose transporter 2 transport system on the basolateral membrane. The small intestine is subdivided into 3 main sections, representing the duodenum, jejunum, and ileum for parameterization. Further subsections are defined between which continual digesta flow is represented. The model predicted nonstructural carbohydrate disappearance in the small intestine for cattle unadapted to duodenal infusion with a coefficient of determination of 0.92 and a root mean square prediction error of 25.4%. Simulation of glucose disappearance for mature Holstein heifers adapted to various levels of duodenal glucose infusion yielded a coefficient of determination of 0.81 and a root mean square prediction error of 38.6%. Analysis of model behavior identified limitations to the efficiency of small intestinal starch digestion with high levels of duodenal starch flow. Limitations to individual processes, particularly starch digestion in the proximal section of the intestine, can create asynchrony between starch hydrolysis and glucose uptake capacity.     

Development of water‐blown bio‐based thermoplastic polyurethane foams using bio‐derived chain extender

Water‐blown bio‐based thermoplastic polyurethane (TPU) formulations were developed to fulfill the requirements of the reactive rotational molding/foaming process. They were prepared using synthetic and bio‐based chain extenders. Foams were prepared by stirring polyether polyol (macrodiol), chain extender (diol), surfactant (silicone oil), chemical blowing agent (distilled water), catalyst, and diisocyanate. The concentration of chain extender, blowing agent, and surfactant were varied and their effects on foaming kinetics, physical, mechanical, and morphological properties of foams were investigated. Density, compressive strength, and modulus of foams decrease with increasing blowing agent concentration and increase with increasing chain extender concentration, but are not significantly affected by changes in surfactant concentration. The foam glass‐transition temperatures increase with increasing blowing agent and chain extender concentrations. The foam cell size slightly increases with increasing blowing agent content and decreases upon surfactant addition (without any dependence on concentration), whereas chain extender concentration has no effect on cell size. Bio‐based 1,3‐propanediol can be used successfully for the preparation TPU foams without sacrificing any properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Properties of Evaporated Si_(1-x)Sn_x and Si_(1_x)Sn_x:H Amorphous Alloys

Amorphous Si_(1-x)Sn_x alloys have been prepared by co-evaporation onto substrates maintained atliquid nitrogen temperature. Their atomic structure is investigated using density measurements,scanning high-energy electron diffraction and Mossbauer spectroscopy. The optical and electricalproperties are reported. Then, a method to hydrogenate the films during the evaporation process isdescribed and applied to the preparation of amorphous semiconductors from pure silicon to pure tin.Finally, multilayers of type Si / Si:H / ... or Si:H / Si:D / ... are studied. The modulation of hydrogen isshown by low-angle neutron scattering and measurements of hydrogen diffusivity are presented.     

Durabilité des réparations en béton projeté

Résumé Le béton projeté est un matériau de plus en plus utilisé, car il est très bien adapté à la réparation des dégradations d'ordre superficiel, dégradations de plus en plus présentes particulièrement dans les pays nordiques. Il existe deux procédés pour projeter le béton: le procédé par voie sèche et le procédé par voie humide. Les travaux à l'Université Laval ont permis de mieux conna?tre l'influence de plusieurs paramètres (ajout de fumée de silice, de fibres, d'adjuvants, etc.) sur les propriétés du béton projeté selon les deux procédés. Très souvent, les propriétés du béton projeté durci ressemblent de très près à celles d'un béton conventionnel de même composition et les résultats des essais ont bien montré qu'il est possible de fabriquer des bétons projetés durables, et qui résistent même au gel en présence de sels fondants. Ils ont aussi montré que la technique de préparation des surfaces à réparer a beaucoup d'influence sur la durabilité de l'adhérence des réparations minces en béton projeté. L'hydrodémolition semble être la technique qui donne les meilleurs résultats.

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Summary The shotcrete technique is certainly one of the most suitable for repairing superficial damage to concrete structures. In certain cases, the use of dry or wet process shotcrete leads to economy in construction costs that are related to the reduction of the time required to realize the project. This paper summarizes various test results obtained at Laval University in recent years on this subject. In dry-mix shotcrete, the use of an air entraining admixture diluted in the water used for the shooting increases the deicer salt scaling resistance, because of a significant decrease in the air void spacing factor. The use of such admixtures, irrespective of the type or the dosage (between 10 and 40 ml l⁻¹ water), does not modigy the properties of shotcrete significantly except for its compressive strength. A higher dosage leads to a reduction in strength. The use of a type 10 cement or a type 30 combined with the use of an air entraining admixture leads to excellent properties. For dry-mix shotcretes made with silica fume, the main advantage is a reduction in drying shrinkage and a low chloride ions permeability, but unfortunately these mixtures did not perform well in the deicer salt scaling tests. For wet-mix shotcrete, the use of silica fume seems to bring the same advantages as those obtained in conventional concrete. The advantages are a decrease in drying shrinkage, an increase in the resistance to freeze-thaw cycles, and a small increase in the compressive strength. Also, it seems clear that the spacing factor of the air bubbles in wet-mix shotcrete is very important for resistance to freeze-thaw cycles in the presence or absence of deicer salts. The test results indicate that it is more difficult to produce a durable wet-mix shotcrete that resists scaling in the presence of deicer salts. More research is needed to understand the mechanisms involved. The bonding between good quality shotcrete mixtures (with and without steel fibers) and concrete surfaces prepared by hydrodemolition or chipping with jackhammers followed by sandblasting was found to be generally strong and durable. The other types of surface preparation (grinding, chipping with jackhammers without sandblasting and sandblasting alone) resulted in either lower bonding strengths or a reduction in the bonding strength with time. No significant difference was observed between the bonding strength of dry or wet process shotcrete to a hydrodemolished surface.

     

MIS隧道器件电流-电压特性的数值模拟

本文建立了MLS隧道器件的电流-电压特性的数值模拟程序,提出了一种新的计算方法:龙格-库塔数值积分与边界条件的预估-校正处理相结合的算法.利用建立的程序模拟计算了两种不同氧化层厚度的MIS隧道器件的电流-电压特性.对TiW/Si肖特基二极管,考虑了界面态的静态和动态影响,模拟特性和实验结果相比,令人满意的一致.     

Amplification at 1.3 mu m in a Pr/sup 3+/-doped single-mode fluorozirconate fibre

Gain of 10.5 dB has been achieved at a wavelength of 1.3 mu m, by using a 17 m length of single mode fluorozirconate fibre doped with 560 p.p.m.w. Pr/sup 3+/, and pumped at 1.007 mu m. The gain increased almost linearly with launched pump power, with a slope efficiency of 0.019 dB/mW.<>