- Mala-Jetmarova, Helena, Schwarz, S., Barton, Andrew, Le Roux, S, Smalley, P., Gerke, S.
- Authors: Mala-Jetmarova, Helena , Schwarz, S. , Barton, Andrew , Le Roux, S , Smalley, P. , Gerke, S.
- Date: 2011
- Type: Text , Conference proceedings
- Full Text: false
- Description: Hydraulic simulation models have become a valuable tool to manage water distribution networks commencing from their initial design through their operation, assessment of the level of service to customers, system performance improvement, analysis of planning alternatives, to system optimisation. The development of hydraulic models can be a time consuming task with complex and large scale water distribution networks being particularly challenging. The Wimmera Mallee Pipeline (WMP) in Western Victoria, Australia is a recently constructed and unique regional scale water distribution system which consists of over 8,800 km of pressurised pipelines spreading across an area of approximately 20,000 km 2. Currently, the WMP provides water to 34 townships, rural farms and other water users across the Wimmera Mallee region with an annual design capacity of 31.6 mil. m 3. The WMP sources its water from multiple reservoirs in the Grampians mountain ranges in the south and the River Murray in the north. Grampians Wimmera Mallee Water (GWMWater) is the local water organisation responsible for managing the WMP. GWMWater is currently initiating the development of a water market to generate and support growth, and to ensure that water is available for the highest value social, economic or environmental use. The hydraulic models discussed in this paper will assure that informed decisions are made by GWMWater regarding the capacity to deliver water through the pipeline system, and therefore the extent of trade by customers. The philosophy for development of the WMP hydraulic models was to replicate the real system as credibly as possible into the level of required accuracy for decision making, yet enable simple model operation, maintenance and update. The network is modelled to the individual customer level in order to accommodate small diameter pipes. Modelling at this level simplifies the future model maintenance and updates, and also ensures the compatibility with other GWMWater's systems such as Geographic Information System (GIS) and the customer database. A major part of the model development consisted of data preparation. This was undertaken by using "as constructed" GIS asset data captured during the WMP construction and entered into a GIS database (ArcGIS by ESRI). Due to the scale of the system and associated amounts of data, it was essential to develop sophisticated data transformation and validation procedures to simplify the model build which thereby minimised manual data entry and potential sources of errors. This paper focuses on the methodologies and techniques used in data preparation for hydraulic models and development of hydraulic models. An example is also provided of how the models will be used as a decision support tool in water supply and allocation planning.
A comprehensive spectrum trading scheme based on market competition, reputation and buyer specific requirements
- Hassan, Md Rakib, Karmakar, Gour, Kamruzzaman, Joarder, Srinivasan, Bala
- Authors: Hassan, Md Rakib , Karmakar, Gour , Kamruzzaman, Joarder , Srinivasan, Bala
- Date: 2015
- Type: Text , Journal article
- Relation: Computer Networks Vol. 84, no. (2015), p. 17-31
- Full Text:
- Reviewed:
- Description: In the exclusive-use model of spectrum trading, cognitive radio devices or secondary users can buy spectrum resources from licensed users or primary users for a short or long period of time. Considering such spectrum access, a trading model is introduced where a buyer can select a set of candidate sellers based on their reputation and their offers in fulfilling its requirements, namely, offered signal quality, contract duration, coverage and bandwidth. Similarly, a seller can assess a buyer as a potential trading partner considering the buyer's reliability, which the seller can derive from the buyer's reputation and financial profile. In our scheme, seller reputation or buyer reliability can be either obtained from a reputation brokerage service, if one exists, or calculated using our model. Since in a competitive market, the price of a seller depends on that of other sellers, game theory is used to model the competition among multiple sellers. An optimization technique is used by a buyer to select the best seller(s) and optimize purchase to maximize its utility. This may result in buying from multiple sellers of certain amount of bandwidth from each, depending on price and meeting requirements and budget constraints. Stability of the model is analyzed and performance evaluation shows that it benefits sellers and buyers in terms of profit and throughput, respectively. © 2015 Elsevier B.V. All rights reserved.
- Authors: Hassan, Md Rakib , Karmakar, Gour , Kamruzzaman, Joarder , Srinivasan, Bala
- Date: 2015
- Type: Text , Journal article
- Relation: Computer Networks Vol. 84, no. (2015), p. 17-31
- Full Text:
- Reviewed:
- Description: In the exclusive-use model of spectrum trading, cognitive radio devices or secondary users can buy spectrum resources from licensed users or primary users for a short or long period of time. Considering such spectrum access, a trading model is introduced where a buyer can select a set of candidate sellers based on their reputation and their offers in fulfilling its requirements, namely, offered signal quality, contract duration, coverage and bandwidth. Similarly, a seller can assess a buyer as a potential trading partner considering the buyer's reliability, which the seller can derive from the buyer's reputation and financial profile. In our scheme, seller reputation or buyer reliability can be either obtained from a reputation brokerage service, if one exists, or calculated using our model. Since in a competitive market, the price of a seller depends on that of other sellers, game theory is used to model the competition among multiple sellers. An optimization technique is used by a buyer to select the best seller(s) and optimize purchase to maximize its utility. This may result in buying from multiple sellers of certain amount of bandwidth from each, depending on price and meeting requirements and budget constraints. Stability of the model is analyzed and performance evaluation shows that it benefits sellers and buyers in terms of profit and throughput, respectively. © 2015 Elsevier B.V. All rights reserved.
Identifying tobacco retailers in the absence of a licensing system : lessons from Australia
- Baker, John, Masood, Mohd, Rahman, Muhammad Aziz, Thornton, Lukar, Begg, Stephen
- Authors: Baker, John , Masood, Mohd , Rahman, Muhammad Aziz , Thornton, Lukar , Begg, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Tobacco Control Vol. 31, no. 4 (2021), p. 543-548
- Full Text:
- Reviewed:
- Description: ObjectivesTo estimate the proportion of retailers that sell tobacco in the absence of appropriate local government oversight, and to describe the characteristics by which they differ from those that can expect to receive such oversight.MethodsA database of listed tobacco retailers was obtained from a regional Victorian local government. Potential unlisted tobacco retailers were added using online searches, and attempts to visit all retailers were undertaken. GPS coordinates and sales type information of retailers that sold tobacco were recorded and attached to neighbourhood-level data on socioeconomic disadvantage and smoking prevalence using ArcMap. Logistic regression analyses, χ2 tests and t-tests were undertaken to explore differences in numbers of listed and unlisted retailers by business and neighbourhood-level characteristics.ResultsOf 125 confirmed tobacco retailers, 43.2% were trading potentially without government oversight. Significant differences were found between listed and unlisted retailers by primary business type (p<0.001), and sales type (p<0.001) but not by the other characteristics.ConclusionsThe database of tobacco retailers was inaccurate in two ways: (1) a number of listed retailers no longer operated or sold tobacco, and (2) 43.2% of businesses confirmed as selling tobacco were missing. As no form of licensing system exists in Victoria, it is difficult to identify the number of retailers operating, or to determine how many receive formal regulatory oversight. A positive licensing system is recommended to regulate the sale of tobacco and to generate a comprehensive database of retailers, similar to that which exists for food registration, gaming and liquor-licensed premises.
- Authors: Baker, John , Masood, Mohd , Rahman, Muhammad Aziz , Thornton, Lukar , Begg, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Tobacco Control Vol. 31, no. 4 (2021), p. 543-548
- Full Text:
- Reviewed:
- Description: ObjectivesTo estimate the proportion of retailers that sell tobacco in the absence of appropriate local government oversight, and to describe the characteristics by which they differ from those that can expect to receive such oversight.MethodsA database of listed tobacco retailers was obtained from a regional Victorian local government. Potential unlisted tobacco retailers were added using online searches, and attempts to visit all retailers were undertaken. GPS coordinates and sales type information of retailers that sold tobacco were recorded and attached to neighbourhood-level data on socioeconomic disadvantage and smoking prevalence using ArcMap. Logistic regression analyses, χ2 tests and t-tests were undertaken to explore differences in numbers of listed and unlisted retailers by business and neighbourhood-level characteristics.ResultsOf 125 confirmed tobacco retailers, 43.2% were trading potentially without government oversight. Significant differences were found between listed and unlisted retailers by primary business type (p<0.001), and sales type (p<0.001) but not by the other characteristics.ConclusionsThe database of tobacco retailers was inaccurate in two ways: (1) a number of listed retailers no longer operated or sold tobacco, and (2) 43.2% of businesses confirmed as selling tobacco were missing. As no form of licensing system exists in Victoria, it is difficult to identify the number of retailers operating, or to determine how many receive formal regulatory oversight. A positive licensing system is recommended to regulate the sale of tobacco and to generate a comprehensive database of retailers, similar to that which exists for food registration, gaming and liquor-licensed premises.
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