Modified harmony search algorithm for location-inventory-routing problem in supply chain network design with product returns

This paper presents a study on the integration of location-inventory-routing problem by considering the returned products of an economic production quantity model in supply chain network design. This model assumes that the returned products can be re-furbished and re-entered into the market to be re-sold. The problem aims to minimise the total cost of establishing the depots, the cost of setup the production and inventory holding, and the cost of delivery travelled by the vehicles. This problem is solved by a proposed Modified Harmony Search (MHS) algorithm with dynamic parameter setting and multi-local neighbourhood search techniques. Computational experiments on benchmark instances show that the proposed MHS outperformed a standard HS for all cases, as well as most of the approaches from the literature

The effect of curriculum design on the employability competency of Malaysian graduates

For a country to support the transition of all economic sectors to a knowledge-driven one, attract foreign investment, and drive labor productivity, it is necessary to have access to skilled workforce. However, there is currently an insufficient talent supply and the workforce demand does not match the talent supply because of low graduate employability stemming from the low quality of higher education in Malaysia. To address this issue, this study proposed a conceptual framework to illustrate the perception of graduates towards the impact of curriculum design, the curriculum vision, the operationalization of the curriculum vision, the curriculum delivery, and curriculum evaluation, on employability competency. A sample of 299 employed graduates participated in this research. Smart Partial Least-Squares (SmartPLS) version 3 software was used to evaluate the hypotheses of the survey. The findings of this study reveal that curriculum design positively and significantly influenced employability competency. Hence, this study contributes important insights into the implementation of effective curriculum design, striking a balance between practical and theoretical bases, in private and public Higher Education Institutions (HEIs)

Harmony search for multi-depot vehicle routing problem

This study considers the multi-depot vehicle routing problem in supply chain network design. Vehicle routing is one of the important system in supply chain. The objective is to find the minimum distance travelled by the vehicles, from the depot to the customers. We proposed an improved harmony search algorithm for solving this problem. Firstly, the Clarke & Wright saving algorithm is used for the initialisation of a solution vector in harmony search. Three simple heuristics approaches; swapping, insertion and relocation are proposed as the local optimisation techniques during the implementation of the harmony search. The roulette wheel approach is implemented for the selection procedure. Computational experiments are conducted using the benchmark dataset of Cordeau's problem instances. Computational results show that the proposed harmony search algorithm is comparable to other metaheuristic approaches from the literature

Harmony search algorithm for location-routing problem in supply chain network design

The interdependence of facility location and vehicle routing has been recognized among the practitioners and researchers. The integration of these problems is more challenging in a supply chain network design problem. This paper considers a location-routing problem, which integrates the facility location problem and the vehicle routing problem. To effectively solved the problem, it is decomposed into three sub problems which are: location-allocation problem, multi-depot vehicle routing problem and multi-depot routing-allocation problem. The objective is to minimize the total operating facilities cost and the total travel distance cost between the depots and customers. A harmony search algorithm is proposed with several local optimisation approaches to further enhance the solution quality. The problem is tested with several benchmark dataset from the literature. The performance of the proposed algorithm is compared with other heuristic and metaheuristic approaches from the literature

Studies on heavy metal contaminantion of water and sediment from Pahang River, Pahang, Malaysia

A study was conducted in order to determined heavy metal concentration in water and sediment at selected sites of Sg. Pahang, Pekan, Pahang (Pahang River). A total of three monitoring stations were established along Sg. Pahang. Three selected sampling point is located near Kampung Batu Sawar, Kampung Padang Rambia and Taman Merdeka, Pahang. Samplings were conducted seven times over a period of seven months from March 2010 to September 2010. Concentrations of heavy metals such as Zinc (Zn), Plumbum (Pb ), Copper (Cu) and Cadmium (Cd) were determined. The results were then compared with the Interim National Water Quality Standards for Malaysia (INWQS). In determination of heavy metals, water and sediment samples were analysed using Atomic Absorption Spectrophotometer (AAS). Results of this study indicated that Sg. Pahang is classified into Class I -Class II base on (INWQS). The trend of heavy metals in water and sediments of Sg. Pahang is Zn> Pb> Cu> Cd. All heavy metals were detected at low concentartion in water and sediment samples. The concentrations of heavy metals in the river water ranged between Zn, (15.22 - 52.91) µg/L.; Pb, (2.75- 12.38); µg/L. Cu, (2.79- 9.92) µg/L.; Cd, (0.16- 0.37) µg/L and the concentrations of heavy metals in sediment ranged between Zn, (20.92- 189.34) µg/g.; Pb, (8.91 - 38.52) µg/g.; Cu, (3.83 - 26.54) µg/g. It was found that the concentration for metals increased as the river water flow from Kampung Batu Sawar to Taman Merdeka. This may be due to agricultural activities, sand mining, fishing activities, sea dumping and industrial development near Pekan. Generally, the concentrations of heavy metals were relatively low and it can be concluded that the river status is clean and under Class II

The kinetics and mechanism of micelle-vesicle transitions in aqueous solution

Bi-chained surfactants, e.g. sodium dialkylbenzenesulphonates, can spontaneously form vesicles when salts (e.g. NaCl) are added to water. Critical vesicle concentrations can be readily determined. The kinetics and mechanism for the breakdown and formation of vesicles will be discussed. A mechanism for assembly/disassembly is proposed. Organic dyes can be encapsulated inside the vesicles and their release rates can be monitored using flow experiments. It is found that the vesicle bilayer provides a rather low energy barrier to the transport of the dye from the vesicle core to the external aqueous medium