Pressure drop and optimization meta-models for arbitrary low-height pleated filter shapes and flowrates

Journal of Mechanical Science and Technology - This study delivers equations useful for low-height pleated fibrous filter design: two pressure drop equations and one set of optimum design equations...     

Digital self-control interventions for distracting media multitasking - A systematic review

Digital distractions can interfere with goal attainment and lead to undesirable habits that are hard to get red rid of. Various digital self-control interventions promise support to alleviate the negative impact of digital distractions. These interventions use different approaches, such as the blocking of apps and websites, goal setting, or visualizations of device usage statistics. While many apps and browser extensions make use of these features, little is known about their effectiveness. This systematic review synthesizes the current research to provide insights into the effectiveness of the different kinds of interventions. From a search of the ‘ACM’, ‘Springer Link’, ‘Web of Science’, ’IEEE Xplore’ and ‘Pubmed’ databases, we identified 28 digital self-control interventions. We categorized these interventions according to their features and their outcomes. The interventions showed varying degrees of effectiveness, and especially interventions that relied purely on increasing the participants' awareness were barely effective. For those interventions that sanctioned the use of distractions, the current literature indicates that the sanctions have to be sufficiently difficult to overcome, as they will otherwise be quickly dismissed. The overall confidence in the results is low, with small sample sizes, short study duration, and unclear study contexts. From these insights, we highlight research gaps and close with suggestions for future research.     

Output Feedback Regulation of a Class of Lower Triangular Nonlinear Systems with Arbitrary Unknown Measurement Sensitivity

International Journal of Control, Automation and Systems - In this paper, a regulation problem for a class of lower triangular nonlinear systems under unknown measurement sensitivity by output...     

PLC-RF diversity: channel outage analysis

Telecommunication Systems - Signals from indoor access points in a wireless fidelity suffer from high attenuation as a result of the thick walls and metal structures in the multilevel-storey...     

Sparse field level set method for non-convex Hamiltonians in 3D plasma etching profile simulations

Level set method [S. Osher, J. Sethian, J. Comput. Phys. 79 (1988) 12] is a highly robust and accurate computational technique for tracking moving interfaces in various application domains. It originates from the idea to view the moving front as a particular level set of a higher dimensional function, so the topological merging and breaking, sharp gradients and cusps can form naturally, and the effects of curvature can be easily incorporated. The resulting equations, describing interface surface evolution, are of Hamilton-Jacobi type and they are solved using techniques developed for hyperbolic equations. In this paper we describe an extension of the sparse field method for solving level set equations in the case of non-convex Hamiltonians, which are common in the simulations of the profile surface evolution during plasma etching and deposition processes. Sparse field method itself, developed by Whitaker [R. Whitaker, Internat. J. Comput. Vision 29 (3) (1998) 203] and broadly used in image processing community, is an alternative to the usual combination of narrow band and fast marching procedures for the computationally effective solving of level set equations. The developed procedure is applied to the simulations of 3D feature profile surface evolution during plasma etching process, that include the effects of ion enhanced chemical etching and physical sputtering, which are the primary causes of the Hamiltonian non-convexity.     

Enhanced thermal stability of a sputtered titanium-nitride film as a diffusion barrier for capacitor-bottom electrodes

The effect of a thin RuO_x layer formed on the Ru/TiN/doped poly-Si/Si stack structure was compared with that on the RuO_x/TiN/doped poly-Si/Si stack structure over the post-deposition annealing temperature ranges of 450–600°C. The Ru/TiN/poly-Si/Si contact system exhibited linear behavior at forward bias with a small increase in the total resistance up to 600°C. The RuO_x/TiN/poly-Si/Si contact system exhibited nonlinear characteristics under forward bias at 450°C, which is attributed to no formation of a thin RuO_x layer at the RuO_x surface and porous-amorphous microstructure. In the former case, the addition of oxygen at the surface layer of the Ru film by pre-annealing leads to the formation of a thin RuO_x layer and chemically strong Ru-O bonds. This results from the retardation of oxygen diffusion caused by the discontinuity of diffusion paths. In particular, the RuO_x layer in a nonstoichiometric state is changed to the RuO₂-crystalline phase in a stoichiometric state after post-deposition annealing; this phase can act as an oxygen-capture layer. Therefore, it appears that the electrical properties of the Ru/TiN/poly-Si/Si contact system are better than those of the RuO_x/TiN/poly-Si/Si contact system.     

An interregional labour market model incorporating vacancy chains and social security

This paper deals with three aspects of interregional demo-economic models which are important with respect to the analysis of regional labour market developments. First, attention is paid to forecasts of the exogenous regional variables, such as investments, exports, etc. Because data at the regional level are usually scarce, it is suggested to make these projections by means of a top-down model. Second, the social security sector is incorporated in the model framework, because changes in social security benefits, which are common in many Western countries nowaday, usually have substantial impacts on regional economic and demographic structures. Third, a vacancy chain model instead of a simple employment growth equation is tied to the standard demo-economic model framework. In this way not only employment growth but also migration, job mobility and related income effects can be taken into account.     

Reverse short channel effects in high-k gated nMOSFETs

Anomalous threshold voltage roll-up behavior, commonly referred as reverse short channel effect (RSCE), has been observed in high-k (HfO₂ on SiON buffer, Al₂O₃ on SiON buffer) gated submicron nMOSFETs, while the SiO₂ or SiON control samples show normal short channel effect (SCE) behavior. The possible causes such as inhomogeneous channel doping profile and gate oxide thickness variation near S/D ends have been ruled out. The results indicate that interface trap density that dependents on channel length is the main cause of the RSCE observed here. In addition, oxide charge also plays a role.     

Prediction and quality control of the melt index during production of high-density polyethylene

In polyolefin processes the melt index (MI) is the most important control variable indicating product quality. Because of the difficulty in the on-line measurement of MI, a lot of MI estimation and correlation methods have been proposed. In this work a new dynamic MI estimation scheme is developed based on system identification techniques. The empirical MI estimation equation proposed in the present study is derived from the 1 ^st -order dynamic models. Effectiveness of the present estimation scheme was illustrated by numerical simulations based on plant operation data including grade change operations in high density polyethylene (HDPE) processes. From the comparisons with other estimation methods it was found that the proposed estimation scheme showed better performance in MI predictions. The virtual sensor model developed based on the estimation scheme was combined with the virtual on-line analyzer (VOA) to give a quality control system to be implemented in the actual HDPE plant. From the application of the present control system, significant reduction of transition time and the amount of off-spec during grade changes was achieved     

Construction Robot Path-Planning for Earthwork Operations

In developing an intelligent mobile construction robot, a navigation system that can provide an effective and efficient path-planning algorithm is a very important element. The purpose of a path-planning method for a mobile construction robot is to find a continuous collision-free path from the initial position of the construction robot to its target position. This paper presents an improved Bug-based algorithm, called SensBug, which can produce an effective path in an unknown environment with both stationary and movable obstacles. The contributions, which make it possible to generate an effective and short path, are an improved method to select local directions, a reverse mode, and a simple leaving condition. Some emerging technologies that can be used for implementing an intelligent construction robot are introduced in this paper.