Papers by Syariza Abdul Rahman
The selection of landfill, which happens to be an environmental issue, has attracted the attentio... more The selection of landfill, which happens to be an environmental issue, has attracted the attention of many researchers from the fields of waste management and environmental sciences worldwide. Hence, in the attempt to overcome this problem, some decision-making techniques, including Geographic Information Systems (GIS) and Multi-Criteria Decision Analysis (MCDA), have been widely utilized in prior studies, where multiple criteria, particularly in site selection process, have been employed. With that, this article identifies the selection criteria for landfill selection and presents a review concerning decision-making techniques that have been used in past studies for two important phases involved during the process of site selection, namely, (1) preliminary site screening, and (2) assessment of site suitability. As such, some 82 articles chosen from 34 peer-reviewed journals had been investigated in detail. The results showed that 42.68% of the selected articles integrated GIS and M...
Many successful approaches to examination timetabling consist of multiple stages, in which a cons... more Many successful approaches to examination timetabling consist of multiple stages, in which a constructive approach is used for finding a good initial solution, and then one or more improvement approaches are employed successively to further enhance the quality of the solution obtained during the previous stage. Moreover, there is a growing number of studies describing the success of approaches which make use of multiple neighbourhood structures. In this study, we investigate the methods of ordering neighbourhood structures within a Variable Neighbourhood Search approach using a great deluge move acceptance method. We also analyse how this approach performs as an improvement algorithm when combined with different initialisation strategies while performing multiple runs for examination timetabling. The empirical results over a well known examination timetabling benchmark show that the performance of Variable Neighbourhood Search great deluge performs reasonably well, ranking second among previously proposed approaches, with the right choice of initialisation and neighbourhood ordering methods.
A tour-package is a prearranged tour that includes products and services such as food, activities... more A tour-package is a prearranged tour that includes products and services such as food, activities, accommodation, and transportation, which are sold at a single price. Since the competitiveness within tourism industry is very high, many of the tour agents try to provide attractive tour-packages in order to meet tourist satisfaction as much as possible. Some of the criteria that are considered by the tourist are the number of places to be visited and the cost of the tour-packages. Previous studies indicate that tourists tend to choose economical tour-packages and aiming to visit as many places as they can cover. Thus, this study proposed tour-package model using heuristic approach. The aim is to find economical tour-packages and at the same time to propose as many places as possible to be visited by tourist in a given geographical area particularly in Langkawi Island. The proposed model considers only one starting point where the tour starts and ends at an identified hotel. This study covers 31 most attractive places in Langkawi Island from various categories of tourist attractions. Besides, the allocation of period for lunch and dinner are included in the proposed itineraries where it covers 11 popular restaurants around Langkawi Island. In developing the itinerary, the proposed heuristic approach considers time window for each site (hotel/restaurant/place) so that it represents real world implementation. We present three itineraries with different time constraints (1-day, 2-day and 3-day tour-package). The aim of economic model is to minimize the tour-package cost as much as possible by considering entrance fee of each visited place. We compare the proposed model with our uneconomic model from our previous study. The uneconomic model has no limitation to the cost with the aim to maximize the number of places to be visited. Comparison between the uneconomic and economic itinerary has shown that the proposed model have successfully achieved the objective that minimize the tour cost and cover maximum number of places to be visited.
This paper suggests a simple approach to solve future budget allocation problems at Universiti Ut... more This paper suggests a simple approach to solve future budget allocation problems at Universiti Utara Malaysia's library specifically, and with minor justification, all university libraries in general. The general objective of this suggestion is to help the library to allocate its annual budget efficiently whereby the acquisitions budget is distributed to all of its clients in a manner that considers a balance between continuing commitment and new initiatives, a balance between resources to support undergraduate learning and those to support graduate work and research, and a balance between subject disciplines. In order to achieve the goals, the suggested approach starts with the construction of a mathematical model to determine the total amount of its budget that should be allocated to each of its clients. Next, based on the budget allocated to each client, the approach continues with the construction of another mathematical model to determine the budget acquisition distribution for books and journals for each client. Upon determining the amount to be allocated for books and journals, the suggested approach ends with the construction of yet another mathematical model to identify the specific books and journals to be purchased for each client.
European Journal of Operations Research, Jul 19, 2013
In this paper, we investigate adaptive linear combinations of graph coloring heuristics with a he... more In this paper, we investigate adaptive linear combinations of graph coloring heuristics with a heuristic modifier to address the examination timetabling problem. We invoke a normalisation strategy for each parameter in order to generalise the specific problem data. Two graph coloring heuristics were used in this study (largest degree and saturation degree). A score for the difficulty of assigning each examination was obtained from an adaptive linear combination of these two heuristics and examinations in the list were ordered based on this value. The examinations with the score value representing the higher difficulty were chosen for scheduling based on two strategies. We tested for single and multiple heuristics with and without a heuristic modifier with different combinations of weight values for each parameter on the Toronto and ITC2007 benchmark data sets. We observed that the combination of multiple heuristics with a heuristic modifier offers an effective way to obtain good solution quality. Experimental results demonstrate that our approach delivers promising results. We conclude that this adaptive linear combination of heuristics is a highly effective method and simple to implement.
Annals of Operations …, Oct 2011
In this study, we investigate an adaptive decomposition and ordering strategy that automatically ... more In this study, we investigate an adaptive decomposition and ordering strategy that automatically divides examinations into difficult and easy sets for constructing an examination timetable. The examinations in the difficult set are considered to be hard to place and hence are listed before the ones in the easy set in the construction process. Moreover, the examinations within each set are ordered using different strategies based on graph colouring heuristics. Initially, the examinations are placed into the easy set. During the construction process, examinations that cannot be scheduled are identified as the ones causing infeasibility and are moved forward in the difficult set to ensure earlier assignment in subsequent attempts. On the other hand, the examinations that can be scheduled remain in the easy set. Within the easy set, a new subset called the boundary set is introduced to accommodate shuffling strategies to change the given ordering of examinations. The proposed approach, which incorporates different ordering and shuffling strategies, is explored on the Carter benchmark problems. The empirical results show that the performance of our algorithm is broadly comparable to existing constructive approaches.
… , 2009. ISCIS 2009. …, 2009
In this paper, we combine graph coloring heuristics, namely largest degree and saturation degree ... more In this paper, we combine graph coloring heuristics, namely largest degree and saturation degree with the concept of a heuristic modifier under the framework of squeaky wheel optimization for solving a set of examination timetabling problems. Both heuristics interact intelligently and adaptively determine the ordering of examinations to be processed during each of iteration. A variety of approaches based on different heuristics and their combinations are investigated. Experimental results on a set of benchmark problems show that the proposed approaches can produce high quality solutions comparable to the other constructive methods. For one problem instance, the best results based on constructive heuristics provided in the literature are improved by one of the proposed methods. We conclude that our approach is simple, yet effective.
In Proceedings of the 8th International Conference on the Practice and Theory of Automated Timetabling, (PATAT 2010), 2010
In this study, we investigate an adaptive decomposition strategy that automatically divides exami... more In this study, we investigate an adaptive decomposition strategy that automatically divides examinations into difficult and easy sets for constructing an examination timetable. The examinations in the difficult set are considered to be hard to place and hence are listed before the ones in the easy set. Moreover, the examinations within each set are ordered using different strategies based on graph colouring heuristics. Initially, the examinations are placed into the easy set. During the construction process, the examinations that cannot be scheduled are identified as the ones causing infeasibility and are moved forward in the difficult set to ensure earlier assignment than the others for the subsequent attempts. On the other hand, the examinations that can be scheduled remain in the easy set. Within the easy set, a new subset called the boundary set
is introduced to accommodate shuffling strategies to change the given ordering of examinations. The proposed approach which incorporates different ordering and shuffling strategies is explored
on the Carter benchmark problems. The empirical results show that its performance is promising and comparable to existing constructive approaches.
In Proceedings of the 24th International Symposium on Computer and Information Sciences, 2009
In this paper, we combine graph coloring heuristics,
namely largest degree and saturation degree... more In this paper, we combine graph coloring heuristics,
namely largest degree and saturation degree with the concept of a
heuristic modifier under the framework of squeaky wheel
optimization for solving a set of examination timetabling
problems. Both components interact adaptively to determine the
best ordering of examinations to be processed at each iteration. A
variety of approaches using different combinations of graph
coloring heuristics and heuristic modifiers are investigated on a
benchmark of examination timetabling problems. Experimental
results show that our approaches can produce high quality
solutions that are comparable to the ones obtained from
previously proposed constructive methods. We conclude that our
approach is simple, yet effective.
Journal of Statistical …, 2011
This paper suggests a simple approach to solve future budget allocation problems at Universiti Ut... more This paper suggests a simple approach to solve future budget allocation problems at Universiti Utara Malaysia's library specifically, and with minor justification, all university libraries in general. The general objective of this suggestion is to help the library to allocate its annual budget efficiently whereby the acquisitions budget is distributed to all of its clients in a manner that considers a balance between continuing commitment and new initiatives, a balance between resources to support undergraduate learning and those to support graduate work and research, and a balance between subject disciplines. In order to achieve the goals, the suggested approach starts with the construction of a mathematical model to determine the total amount of its budget that should be allocated to each of its clients. Next, based on the budget allocated to each client, the approach continues with the construction of another mathematical model to determine the budget acquisition distribution for books and journals for each client. Upon determining the amount to be allocated for books and journals, the suggested approach ends with the construction of yet another mathematical model to identify the specific books and journals to be purchased for each client.
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Papers by Syariza Abdul Rahman
is introduced to accommodate shuffling strategies to change the given ordering of examinations. The proposed approach which incorporates different ordering and shuffling strategies is explored
on the Carter benchmark problems. The empirical results show that its performance is promising and comparable to existing constructive approaches.
namely largest degree and saturation degree with the concept of a
heuristic modifier under the framework of squeaky wheel
optimization for solving a set of examination timetabling
problems. Both components interact adaptively to determine the
best ordering of examinations to be processed at each iteration. A
variety of approaches using different combinations of graph
coloring heuristics and heuristic modifiers are investigated on a
benchmark of examination timetabling problems. Experimental
results show that our approaches can produce high quality
solutions that are comparable to the ones obtained from
previously proposed constructive methods. We conclude that our
approach is simple, yet effective.
is introduced to accommodate shuffling strategies to change the given ordering of examinations. The proposed approach which incorporates different ordering and shuffling strategies is explored
on the Carter benchmark problems. The empirical results show that its performance is promising and comparable to existing constructive approaches.
namely largest degree and saturation degree with the concept of a
heuristic modifier under the framework of squeaky wheel
optimization for solving a set of examination timetabling
problems. Both components interact adaptively to determine the
best ordering of examinations to be processed at each iteration. A
variety of approaches using different combinations of graph
coloring heuristics and heuristic modifiers are investigated on a
benchmark of examination timetabling problems. Experimental
results show that our approaches can produce high quality
solutions that are comparable to the ones obtained from
previously proposed constructive methods. We conclude that our
approach is simple, yet effective.