Mechanical

In this paper, a design for robust facility layout is proposed under the dynamic demand environment. The general strategy for a multi period layout planning problem is adaptive approach. This approach for Dynamic Plant Layout Problem (DPLP) assumes that a layout will accommodate changes from time to time with low rearrangement and production interruption costs, and that the machines can be easily relocated. On the other hand the robust layout approach, assumes that rearrangement and production interruption costs are too high and hence, tries to minimize the total material handling costs in all periods using a single layout. Robust approach suggests a single layout for multiple scenarios as well as for multiple periods. As a solution procedure for the proposed model, a Simulated Annealing (SA) algorithm is suggested, which perform well for the problems from literature and QAPLIB website. The application of suggested model for robust layout to cellular layouts has given better results compared to the robust cellular layout model of literature. For the standard DPLP of the literature, the solution values of the suggested model are very near to the results of adaptive approach. The Total Penalty Cost (TPC) is used to test the suitability of the suggested layout to be a robust layout for the given data set. TPC values indicate that the suggested layout is suitable as robust layout for the given data sets.

In this paper, a design for robust facility layout is proposed under the dynamic demand environment. The general strategy for a multi period layout planning problem is adaptive approach. This approach for Dynamic Plant Layout Problem (DPLP) assumes that a layout will accommodate changes from time to time with low rearrangement and production interruption costs, and that the machines can be easily relocated. On the other hand the robust layout approach, assumes that rearrangement and production interruption costs are too high and hence, tries to minimize the total material handling costs in all periods using a single layout. Robust approach suggests a single layout for multiple scenarios as well as for multiple periods. As a solution procedure for the proposed model, a Simulated Annealing (SA) algorithm is suggested, which perform well for the problems from literature and QAPLIB website. The application of suggested model for robust layout to cellular layouts has given better results compared to the robust cellular layout model of literature. For the standard DPLP of the literature, the solution values of the suggested model are very near to the results of adaptive approach. The Total Penalty Cost (TPC) is used to test the suitability of the suggested layout to be a robust layout for the given data set. TPC values indicate that the suggested layout is suitable as robust layout for the given data sets.

Based on a power system model, this paper studies how different policy decision evolves the future Indian electricity system of the year 2040. As of 2017, fossil fuels provided 80% of the electricity generation in India and there is a critical concern of increasing emissions in the future with a steady increase in demand. To overcome this concern, the Indian Government promotes the greening of the electricity system by setting renewable energy addition targets and other favourable policies. This paper mainly focuses on the long-term goal set in the draft national energy policy 2017, aiming 36% renewable energy in the power generation mix in 2040.

The present work investigates the potential of different biomasses for air-steam gasification using thermodynamic equilibrium model. A stoichiometric thermodynamic equilibrium model considering char conversion and tar formation is developed using MATLAB software to compare the gasification performance of different biomasses in terms of product gas yield, heating value and energy efficiency. Regression analysis is performed and correlations for the yield of different syngas constituents are developed in terms of temperature, steam to biomass ratio and equivalence ratio for all the biomasses. For a temperature of 1000 K, steam to biomass ratio of unity and equivalence ratio of 0.25, maximum mole fraction of hydrogen (14.89 %) was obtained from rubber seed shell with a lower heating value and gas yield of 4.71 MJ/Nm 3 and 1.18 Nm 3 /h, respectively.

Retailers often use discount pricing and promotional efforts to prop up declining demand of deteriorating item nearing the end of their shelf life. In this context, we study the problem of discount pricing, promotion and ordering of noninstantaneous deteriorating single period product subject to promotional efforts and deterioration. In this paper, we first modify price-and time-dependent demand function (covering demand running through stages of market lifecycle) to include demand accrued from the promotional efforts and then develop inventory model to determine discount selling price and order size that maximizes total profit considering the deterioration. Later, the optimal selling period is determined using enumerative search method. The numerical examples presented to illustrate results show the benefits of exerting optimal level of promotional efforts; benefits of lengthening the non-deterioration period-larger profit with smaller order size; existence of optimal selling period; deleterious effect of deterioration-reduced profit even with enlarged order size. The model developed for non-instantaneous deteriorating item can be used for non-deteriorating as well as instantaneous deteriorating item.

In the literature, most mathematical models for supply chains assume that transportation links will not fail. However, in reality, transportation links are subject to various sorts of disruptions. Furthermore, in most supply chain models, there is little consideration given to the diminishing value of the product. In this paper, we have designed an integrated supply chain network for perishable products that takes into account random disruptions in transportation links. We also consider several capacitated manufacturing facilities and retail outlets and stochastic demands. This model considers both demand and process uncertainty (which is incorporated through random disruptions in the transportation link between the manufacturers and the retailers), simultaneously. The model also investigates the manufacturer’s facility locations and shipment decisions in the supply chain and minimizes the total cost of the entire supply chain. The paper discusses the model output through a numerica...

Purpose-Since the 2010s, market conditions for container shipping companies have been deteriorating owing to decreasing container cargo trade and increasing supply capacity. This study aims to contribute to the empirical literature on the container shipping industry market structure. Specifically, this study aims to investigate the extent of market competition. Design/methodology/approach-This study analyzes the market structure and evaluates the market power of shipping companies through a non-structural test. Findings-The H-statistic for the entire period of 2004-2018 was 0.37, which is significantly different from zero. This indicates the absence of monopoly pricing throughout the entire period. For the time-phased estimates, the H-statistic between 2004 and 2008 is 0.15, which is not significantly different from zero. On the other hand, the H-statistic from 2009 to 2018 was 0.40, which differs significantly from zero. Originality/value-As the Far East Freight Conference had released tariffs and charge rates by item for container shipping routes, monopolistic pricing is said to have appeared until the European Union abolished the European Economic Community (No. 4056/86) in 2008, before the economic crisis. However, this study indicates that pricing in the container shipping industry has been distinctly non-monopolistic; further, competition seems to have intensified since 2008. Industry competitiveness is of interest not only to academics but also to practitioners, including policymakers, especially when considering competition policies.

Design of a solar system is complex because of the
presence of both predictable and unpredictable
parameters. Predictable parameters include
performance characteristics of collectors and other
components and the latter mainly concern weather data
such as solar radiation, ambient temperature, wind
speed and direction. This work analyzes the use of fchart
method in designing liquid solar heating systems
due to its simplicity and ability to estimate the fraction
of total heating load supplied by solar heating system.
This method can be used for designing both active and
passive solar heating systems, especially in selecting
the sizes and type of solar collectors that provide the
hot water and heating loads. Paper includes the design
of a solar water heating system for a family of six
members in CALICUT using f-chart method. Variation
of fraction of total load supplied by solar energy is
studied. Optimum collector area for the required load
is found out.

In this work, the direct position kinematics of a 3 degree-of-freedom parallel manipulator with three identical limbs, type revolute-prismatic-spherical (RPS), is analyzed. In contrast to the previous studies on this class of manipulators, the revolute joints of the proposed manipulator are actuated rather than the prismatic joints. Direct position kinematics of the manipulator leads to a system of three nonlinear equations in three unknowns that are reduced to a univariate polynomial of degree eight and two quadratic equations in sequence using Sylvester dialytic elimination method. In addition, to show the efficiency of the presented method a numerical example is provided.