Information hiding in product development: the design churn effect

Execution of a complex product development project is facilitated through its decomposition into an interrelated set of localized development tasks. When a local task is completed, its output is integrated through an iterative cycle of system-wide integration activities. Integration is often accompanied by inadvertent information hiding due to the asynchronous information exchanges. We show that information hiding leads to persistent recurrence of problems (termed the design churn effect) such that progress oscillates between being on schedule and falling behind. The oscillatory nature of the PD process confounds progress measurement and makes it difficult to judge whether the project is on schedule or slipping. We develop a dynamic model of work transformation to derive conditions under which churn is observed as an unintended consequence of information hiding due to local and system task decomposition. We illustrate these conditions with a case example from an automotive development project and discuss strategies to mitigate design churn.

Development and gamma-scintigraphy study of Hibiscus rosasinensis polysaccharide-based microspheres for nasal drug delivery

Objective: This work describes the application of natural plant polysaccharide as pharmaceutical mucoadhesive excipients in delivery systems to reduce the clearance rate through nasal cavity.

Methods: Novel natural polysaccharide (Hibiscus rosasinensis)-based mucoadhesive microspheres were prepared by using emulsion crosslinking method for the delivery of rizatriptan benzoate (RB) through nasal route. Mucoadhesive microspheres were characterized for different parameters and nasal clearance of technetium-99m (^99mTc)-radiolabeled microspheres was determined by using gamma-scintigraphy.

Results: Their Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies showed that the drug was stable during preparation of microspheres. Aerodynamic diameter of microspheres was in the range 13.23?±?1.83–33.57?±?3.69?µm. Change in drug and polysaccharide ratio influenced the mucoadhesion, encapsulation efficiency and in-vitro release property. Scintigraphs taken at regular interval indicate that control solution was cleared rapidly from nasal cavity, whereas microspheres showed slower clearance (p?Conclusion: Natural polysaccharide-based microspheres achieved extended residence by minimizing effect of mucociliary clearance with opportunity of sustained delivery for longer duration.     

Microstructure and Property Evolution for Hot-Rolled and Cold-Rolled Austenitic Stainless Steel 316L

Grain boundary character distribution plays an important role in determining the functional and mechanical properties of polycrystalline materials. The aim of this work was to achieve improved coincident site lattice (CSL) fraction without increasing low angle grain boundary (LAGB) proportion. We utilized single-step thermo-mechanical processing route involving rolling followed by short heat treatment and compared the effect of rolling temperature. Our results indicated that rolling at elevated temperature led to significant increase in the fraction of special boundaries while keeping the fraction of LAGB very low, as desired. We conducted thermal stability of our sample-conditions at elevated temperatures for various lengths of time and found the microstructure of the samples to be stable up to 1000 °C. This study showed that even commercially suitable process (single step processing with short heat treatment duration) could lead to microstructure with considerable increase in CSL boundaries fraction, improved hardness values and good thermal stability.     

Breakthrough Curves and Simulation of Virus Transport through Fractured Porous Media

In this paper, an advective dispersive virus transport equation, including first-order adsorption and an inactivation constant, is used for simulating the movement of viruses in fractured porous media. The implicit finite-difference numerical technique is used to solve the governing equations for viruses in the fractured porous media. In this work, the focus is (1)?to investigate the transport processes of the movement of viruses in both fractured rock and porous rock without fracture and (2)?to simulate the experimental data of biocolloids through a fractured aquifer model. It is seen that movement of the contaminant is faster in the fractured rock than in the porous rock formation. Higher values of diffusion coefficient, matrix porosity, mass transfer constant, and inactivation rate reduce both temporal and spatial virus concentrations in the fracture. Also, experimental data of biocolloids in the fractured aquifer model with constant and time-dependent inactivation rates were simulated successfully.     

The influence of the coating technique on the high cycle fatigue life of alumina coated Al 6061 alloy

The primary objective of this study is to evaluate the influence of coating technique on the high cycle fatigue of an Al6061 alloy. Towards this purpose, Al6061 alloy fatigue samples have been coated with Al₂O₃ utilising the detonation spray, air plasma spray, micro arc oxidation and hard anodizing techniques. The high cycle fatigue life of these coated samples has been evaluated over a range of alternating stress values and compared with the fatigue life of the uncoated Al6061 alloy. It is observed that the detonation spray coated sample exhibits a higher fatigue life than the uncoated sample. In contrast, the samples coated using the other techniques exhibit poorer fatigue life compared to the uncoated sample especially at lower alternating stress values. These results have been explained on the basis of the nature of the coating-substrate interface which is strongly determined by the coating technique used to deposit the Al₂O₃ coatings.     

Linear-code multicast on parallel architectures

Parallel architectures involve communication with the aim of fast receiving of complete information at each node. Several architectures have been proposed to overcome the problem of high communicational and computational time complexity for transferring and receiving information. To reduce the complexity of such communication, we have implemented Linear Network Coding (LNC) in the parallel environment. For verification of our approach, we have considered some parallel architecture for implementing network coding approach and examined our results on these networks in a generic environment. We have formulated a standard approach for parallel networks, showing that by applying this approach effect of faulty nodes, information size and communication complexity exponentially decreases with code length.     

A Mechanism for Carbon Depletion at Bondline of High-Frequency Electric-Resistance-Welded X70 Pipeline Steel

Metallurgical and Materials Transactions A - The bondline of electric-resistance-welded (ERW) linepipe steel, often etched white (i.e., ferrite) in optical microscopy, is generally believed to be...     

Efficient use of commercial electromagnetic simulators for microwave and millimeter-wave circuits

Efficient use of electromagnetic simulators is accomplished by classification of EM problems into three categories—characterization of circuit elements, optimization of circuit elements, and creation of circuit element libraries. Real circuit examples in each of the three categories are given to demonstrate the practical aspects of efficient EM simulations and the computer resources required. © 1995 John Wiley & Sons, Inc.     

A novel fault detection and recovery technique for cluster‐based underwater wireless sensor networks

The performance of underwater wireless sensor network gets affected by the working of a cluster in the network. The cluster head (CH) or cluster member (CM) fails because of energy depletion or hardware errors that increase delay and message overhead of the network. To recover the affected cluster, a technique is required to identify the failed CH or CM. We propose a fault detection and recovery technique (FDRT) for a cluster‐based network in this paper. Primarily, while selecting the CH, a backup cluster head (BCH) is selected using fuzzy logic technique based on parameters such as node density, residual energy, load, distance to sink, and link quality. Then, failure of CH, BCH, and CM is detected. If fault is detected at CH, then the BCH will start performing the task of failed CH. Simultaneously, when BCH failed, any other CM will be elected as BCH. If any of the CM appears to be nonperforming, then CH will detect the communication failure and request BCH to transfer the data from the failed CM to CH. The comparison of proposed FDRT is performed with existing FDRTs EDETA, RCH, and SDMCGC on the basis of packet drop, end‐to‐end delay, energy consumption, and delivery ratio of data packets. By simulation results, it is shown that FDRT for cluster‐based underwater wireless sensor network results in quicker detection of failures and recovery of the network along with the reduction in energy consumption, thereby increasing the lifespan of the network.