The Implications of Parental and Child Smartphone Use on Parent-Child and Family Relationships: a Case-Study of the Turkish-Speaking Community in London

This qualitative research study explores the implications of parental and child smartphone use on parent-child and family relationships. It also explores the role of smartphones in children’s contact with distant family members and the implications of smartphones for children’s learning, health and entertainment. In exploring all these, this thesis aims to contribute to the literature on digital device use and its various implications for immigrant ethnic minority children and families. The theoretical framework of this study draws on different strands of literature at the intersection of parent-child relationship and media. By focusing on this intersection, the study explores how the experiences and perceptions of parent-child and family relationships are influenced by smartphone use. The study data are based on semi-structured, in-depth interviews with 14 families, 19 interviews with children and 15 interviews with parents. The study concluded that with the wide integration of smartphones into family life, there are interferences with the everyday experiences of parent-child and family time. It also concluded that immersion into and/or distraction by smartphones weakens the quality of parent-child communication, parent-child relationship and parenting. The study further concluded that smartphones play a positive role in children’s connection with their extended family members in Turkey, which was valued both by the children and their parents. In terms of the role of smartphones for children’s entertainment, for all of the interviewed children smartphones were found to be playing a significant role in this respect. As for smartphones’ role in children’s learning, most of the interviewed children seemed to value smartphones as a tool that helps them with their learning and feeding their interests. Children and parents associated positive feelings with children's smartphone use for learning whilst describing their non-educational smartphone use as a “waste of time” or “useless”. With respect to the impact of smartphone use on children's health, both parents and children reported concerns in this respect. The findings of this study highlight that the way smartphones are used can either lead them to be perceived as facilitating and connecting devices that lead to improved connection and satisfaction whilst meeting various needs or separating devices that fracture/interfere with parent-child and family relationships, which can in turn be a source of conflict and dissatisfaction. This thesis is a first step in illustrating the implications of smartphone use on parent-child and family relationships in the Turkish-speaking community in London. Further diverse research on this subject on immigrant ethnic minority communities will help to gain a broader understanding of the implications of digital device use on parent-child and family relationships within immigrant ethnic minority communities

A multi-stage stochastic programming approach in master production scheduling

Master Production Schedules (MPS) are widely used in industry, especially within Enterprise Resource Planning (ERP) software. The classical approach for generating MPS assumes infinite capacity, fixed processing times, and a single scenario for demand forecasts. In this paper, we question these assumptions and consider a problem with finite capacity, controllable processing times, and several demand scenarios instead of just one. We use a multi-stage stochastic programming approach in order to come up with the maximum expected profit given the demand scenarios. Controllable processing times enlarge the solution space so that the limited capacity of production resources are utilized more effectively. We propose an effective formulation that enables an extensive computational study. Our computational results clearly indicate that instead of relying on relatively simple heuristic methods, multi-stage stochastic programming can be used effectively to solve MPS problems, and that controllability increases the performance of multi-stage solutions

Kinematic synthesis of flight control systems for light aircrafts

In this paper, kinematic synthesis of a planar flight control system mechanism has been conducted for a light aircraft designed and built by TAL To achieve a simple construction, the four-bar linkages are used in the synthesis. Freudenstein's Method and Bloch's Method are utilized for analytical three and four bar position syntheses respectively. A case study of an elevator flight control system is presented

Large and dynamical tuning of a chalcogenide Fabry-Perot cavity mode by temperature modulation

Cataloged from PDF version of article.Te-enriched chalcogenide glass Ge15As25Se15Te45 (GAST) is synthesized, thermo-optically characterized and used to fabricate a one dimensional photonic crystal cavity mode that is dynamically and reversibly tuned by temperature modulation. The optical cavity mode is designed using GAST and As2S3 glasses after fully determining their temperature dependence of the complex refractive indices in the visible and near infrared spectrum using spectroscopic ellipsometry. By making use of the very large thermo-optic coefficient (dn/dT = 4x10(-4)/degrees C) of GAST glass at 1.2 mu m, the cavity mode of the multilayer was tuned reversibly more than 16 nm, which is, to the best of our knowledge, an order of magnitude larger for this kind of cavity modulation. Wide and dynamical spectral tuning of low bandgap chalcogenide glasses via temperature modulation can be utilized in photonic crystal based integrated optics, quantum dot resonance matching, solid state and gas laser components, and infrared photonic crystal fibers. (C) 2010 Optical Society of Americ

Lot sizing with piecewise concave production costs

Cataloged from PDF version of article.We study the lot-sizing problem with piecewise concave production costs and concave holding costs. This problem is a generalization of the lot-sizing problem with quantity discounts, minimum order quantities, capacities, overloading, subcontracting or a combination of these. We develop a dynamic programming algorithm to solve this problem and answer an open question in the literature: we show that the problem is polynomially solvable when the breakpoints of the production cost function are time invariant and the number of breakpoints is fixed. For the special cases with capacities and subcontracting, the time complexity of our algorithm is as good as the complexity of algorithms available in the literature. We report the results of a computational experiment where the dynamic programming is able to solve instances that are hard for a mixed-integer programming solver. We enhance the mixed-integer programming formulation with valid inequalities based on mixing sets and use a cut-and-branch algorithm to compute better bounds. We propose a state space reduction–based heuristic algorithm for large instances and show that the solutions are of good quality by comparing them with the bounds obtained from the cut-and-branch

Stochastic lot sizing problem with controllable processing times

Cataloged from PDF version of article.In this study, we consider the stochastic capacitated lot sizing problem with controllable processing times where processing times can be reduced in return for extra compression cost. We assume that the compression cost function is a convex function as it may reflect increasing marginal costs of larger reductions and may be more appropriate when the resource life, energy consumption or carbon emission are taken into consideration. We consider this problem under static uncertainty strategy and α service level constraints. We first introduce a nonlinear mixed integer programming formulation of the problem, and use the recent advances in second order cone programming to strengthen it and then solve by a commercial solver. Our computational experiments show that taking the processing times as constant may lead to more costly production plans, and the value of controllable processing times becomes more evident for a stochastic environment with a limited capacity. Moreover, we observe that controllable processing times increase the solution flexibility and provide a better solution in most of the problem instances, although the largest improvements are obtained when setup costs are high and the system has medium sized capacities

Vesicles in solutions of hard rods

The surface free energy of ideal hard rods near curved hard surfaces is determined to second order in curvature for surfaces of general shape. In accordance with previous results for spherical and cylindrical surfaces it is found that this quantity is non-analytical when one of the principal curvatures changes signs. This prohibits writing it in the common Helfrich form. It is shown that the non-analytical terms are the same for any aspect ratio of the rods. These results are used to find the equilibrium shape of vesicles immersed in solutions of rod-like (colloidal) particles. The presence of the particles induces a change in the equilibrium shape and to a shift of the prolate-oblate transition in the vesicle phase diagram, which are calculated within the framework of the spontaneous curvature model. As a consequence of the special form of the energy contribution due to the rods these changes cannot be accounted for by a simple rescaling of the elastic constants of the vesicle as for solutions of spherical colloids or polymers.Comment: 11 pages, 7 figures, submitted to Phys. Rev.

Multi-period supplier selection under price uncertainty

Cataloged from PDF version of article.We consider a problem faced by a procurement manager who needs to purchase a large volume of multiple items over multiple periods from multiple suppliers that provide base prices and discounts. Discounts are contingent on meeting various conditions on total volume or spend, and some are tied to future realizations of random events that can be mutually verified. We formulate a scenario-based multi-stage stochastic optimization model that allows us to consider random events such as a drop in price because of the most favoured customer clauses, a price change in the spot market or a new discount offer. We propose certainty-equivalent heuristics and evaluate the regret of using them. We use our model for three bidding events of a large manufacturing company. The results show that considering most favored customer clauses in supplier offers may create substantial savings that may surpass the savings from regular discount offers

Release Time Scheduling and Hub Location for Next-Day Delivery

Cataloged from PDF version of article.Inspired by a real-life problem faced by one of the largest ground-based cargo companies of Turkey, the current study introduces a new facet to the hub location literature. The release time scheduling and hub location problem aims to select a specified number of hubs from a fixed set of demand centers, to allocate each demand center to a hub, and to decide on the release times of trucks from each demand center in such a way that the total amount of cargo guaranteed to be delivered to every potential destination by the next day is not below a threshold and the total routing cost is minimized. The paper introduces integer programming models to solve this problem in the special cases when the cargo uniformly arrives to each demand center during the day and the more realistic pattern of when the cargo arrivals exhibit a piecewise linear form. Several classes of valid inequalities are proposed to strengthen the formulations. Extensions with multiple service levels and discrete sets for release times are also discussed. Computational results show the computational viability of the models under realistic scenarios as well as the validity of the proposed problems in answering several interesting questions from the cargo sector’s perspective

Structural Coloring in Large Scale Core-Shell Nanowires

Cataloged from PDF version of article.We demonstrated two complementary size-dependent structural coloring mechanisms, interference and scattering, in indefinitely long core-shell nanowire arrays. The unusual nanostructures are comprised of an amorphous semiconducting core and a polymer shell layer with disparate refractive indices but with similar thermomechanical properties. Core-shell nanowires are mass produced from a macroscopic semiconductor rod by using a new top-to-bottom fabrication approach based on thermal size reduction. Nanostructures with diameters from 30 to 200 nm result in coloration that spans the whole visible spectrum via resonant Mie scattering. Nanoshell coloration based on thin film interference is proposed as a structural coloration mechanism which becomes dominant for nanowires having 700-1200 nm diameter. Controlled color generation in any part of visible and infrared spectral regions can be achieved by the simple scaling down procedure. Spectral color generation in mass-produced uniform core-shell nanowire arrays paves the way for applications such as spectral authentication at nanoscale, light-scattering ingredients in paints and cosmetics, large-area devices, and infrared shielding