1,065 research outputs found

    The viability of IS enhanced knowledge sharing in mission-critical command and control centers

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    Engineering processes such as the maintenance of mission-critical infrastructures are highly unpredictable processes that are vital for everyday life, as well as for national security goals. These processes are categorized as Emergent Knowledge Processes (EKP), organizational processes that are characterized by a changing set of actors, distributed knowledge bases, and emergent knowledge sharing activities where the process itself has no predetermined structure. The research described here utilizes the telecommunications network fault diagnosis process as a specific example of an EKP. The field site chosen for this research is a global undersea telecommunication network where nodes are staffed by trained personnel responsible for maintaining local equipment using Network Management Systems. The overall network coordination responsibilities are handled by a centralized command and control center, or Network Management Center. A formal case study is performed in this global telecommunications network to evaluate the design of an Alarm Correlation Tool (ACT). This work defines a design methodology for an Information System (IS) that can support complex engineering diagnosis processes. As such, a Decision Support System design model is used to iterate through a number of design theories that guide design decisions. Utilizing the model iterations, it is found that IS design theories such as Decision Support Systems (DSS), Expert Systems (ES) and Knowledge Management Systems (KMS) design theories, do not produce systems appropriate for supporting complex engineering processes. A design theory for systems that support EKPs is substituted as the project\u27s driving theory during the final iterations of the DSS Design Model. This design theory poses the use of naive users to support the design process as one of its key principles. The EKP design theory principles are evaluated and addressed to provide feedback to this recently introduced Information System Design Theory. The research effort shows that use of the EKP design theory is also insufficient in designing complex engineering systems. As a result, the main contribution of this work is to augment design theory with a methodology that revolves around the analysis of the knowledge management and control environment as a driving force behind IS design. Finally, the research results show that a model-based knowledge captunng algorithm provides an appropriate vehicle to capture and manipulate experiential engineering knowledge. In addition, it is found that the proposed DSS Design Model assists in the refinement of highly complex system designs. The results also show that the EKP design theory is not sufficient to address all the challenges posed by systems that must support mission-critical infrastructures

    A new method for providing a model to analyze a kite wind turbine

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    The ultimate purpose of simulating kite wind turbine is to predict the kite movement and the power generated by its mechanism. To simulate because when the initial estimate of the intended values is found, we may have to manipulate the simulation to find the most efficient design for manufacturing our system and then predict the final power generated for our mechanism. Simulation for the system is based on two parts: Simulation of steady-state and dynamic model, which include differential equations. In this paper, we have presented a novel idea for a proper simulation of the system based on the two static and dynamic parts in order to numerical solution of the required amount and to calculate the output power.Keywords: Kite wind turbine; Simulation; Static model; Dynamic model;Winch; Torqu

    Communication: Nanosize-induced restructuring of Sn nanoparticles

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    Stabilities and structures of β- and α-Sn nanoparticles are studied using density functional theory. Results show that β-Sn nanoparticles are more stable. For both phases of Sn, nanoparticles smaller than 1 nm (∼48 atoms) are amorphous and have a band gap between 0.4 and 0.7 eV. The formation of band gap is found to be due to amorphization. By increasing the size of Sn nanoparticles (1–2.4 nm), the degree of crystallization increases and the band gap decreases. In these cases, structures of the core of nanoparticles are bulk-like, but structures of surfaces on the faces undergo reconstruction. This study suggests a strong size dependence of electronic and atomic structures for Sn nanoparticle anodes in Li-ion batteries

    Fibulin-2 is required for basement membrane integrity of mammary epithelium

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    Fibulin-2 (FBLN2) is a secreted extracellular matrix glycoprotein which has been associated with tissue development and remodelling. In the mouse mammary gland, FBLN2 can be detected during ductal morphogenesis in cap cells and myoepithelial cells at puberty and early pregnancy, respectively. In an attempt to assign its function, we knocked down Fbln2 in the mouse mammary epithelial cell line EpH4. FBLN2 reduction led to an increase in the size of spheroidal structures when compared to scrambled control shRNA-transduced cells plated on Matrigel matrix. This phenotype was associated with a disruption of the collagen IV sheath around the epithelial spheroids and downregulation of integrin β1, suggesting a role for FBLN2 in stabilizing the basement membrane (BM). In contrast to mice, in normal adult human breast tissue, FBLN2 was detected in ductal stroma, and in the interlobular stroma, but was not detectable within the lobular regions. In tissue sections of 65 breast cancers FBLN2 staining was lost around malignant cells with retained staining in the neighbouring histologically normal tissue margins. These results are consistent with a role of FBLN2 in mammary epithelial BM stability, and that its down-regulation in breast cancer is associated with loss of the BM and early invasion

    Fibulin-2 is required for basement membrane integrity of mammary epithelium

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    Fibulin-2 (FBLN2) is a secreted extracellular matrix glycoprotein which has been associated with tissue development and remodelling. In the mouse mammary gland, FBLN2 can be detected during ductal morphogenesis in cap cells and myoepithelial cells at puberty and early pregnancy, respectively. In an attempt to assign its function, we knocked down Fbln2 in the mouse mammary epithelial cell line EpH4. FBLN2 reduction led to an increase in the size of spheroidal structures when compared to scrambled control shRNA-transduced cells plated on Matrigel matrix. This phenotype was associated with a disruption of the collagen IV sheath around the epithelial spheroids and downregulation of integrin β1, suggesting a role for FBLN2 in stabilizing the basement membrane (BM). In contrast to mice, in normal adult human breast tissue, FBLN2 was detected in ductal stroma, and in the interlobular stroma, but was not detectable within the lobular regions. In tissue sections of 65 breast cancers FBLN2 staining was lost around malignant cells with retained staining in the neighbouring histologically normal tissue margins. These results are consistent with a role of FBLN2 in mammary epithelial BM stability, and that its down-regulation in breast cancer is associated with loss of the BM and early invasion

    Age, sex ratio, spawning season, gonadosomatic index, and fecundity of Cobitis faridpaki (Actinopterygii, Cobitidae) from the Siahrud River in the southeastern Caspian Sea basin

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    Cobitis faridpaki Cobitis faridpaki (Mousavi-Sabet, Vasil'eva, Vatandoust and Vasil'ev, 2011) is found in streams of the Siahrud River in the southeastern Caspian Sea basin, and this is the first report on reproductive parameters of the newly described endemic loach. Reproductive conditions are key parameters of fish populations, and their assessment is very important for endemic fishes. To study reproduction biology of this fish, sampling was done at monthly intervals throughout the year and 258 individuals of Cobitis faridpaki, were caught from Siahrud River in the southeastern Caspian Sea basin, in the north of Iran. Age, sex ratio, fecundity, oocytes diameter and gonadosomatic index were estimated. A regression analysis was used to find relationships between fecundity and fish size (length and weight), gonad weight and age. Sex ratio differed significantly from unity and was biased to females. The mature females and males were longer than 40 and 30 mm in total length, and +2 and +1 in age, respectively. The average egg diameter was 0.578 mm. Spawning took place from beginning of May to late July when water temperature was between 19.4 to 25.1 °C. Average GSI value at the beginning of the reproduction period was 9.12% and ranged between 2% to 20% in ripe mature females. The averages of absolute and relative fecundity were calculated as 1366 and 508, respectively. The absolute fecundity was significantly related to body weight and gonad weight. Based on the pattern of gonadosomatic index, it was concluded that this fish has a prolonged active reproduction period, which is a type of adaptation of short-lived small fishes to environmental conditions
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