116 research outputs found

    A MULTI-OBJECTIVE MODEL FOR TIME–COST–QUALITY–RISK TRADE-OFF PROBLEMS IN PROJECT MANAGEMENT

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    This study presents a weighted four-dimensional time-cost-quality-risk trade-off problem to assist decision-makers in planning the best possible use of resources. The proposed model aims to minimize time and cost while maximizing quality and safety and to ensure that the project is completed as required. The critical path method was used to calculate the completion time, the analytical hierarchy process method was used to determine the weights of the quality parameters, and the 3T risk assessment method was used to calculate the risk values. The algorithm was coded in GAMS and optimized using CPLEX. A construction project with a deadline of 310 days, a budget of 5,250,000 â‚ș, 88% quality and a safety index (SI) of 77% was selected to analyze the accuracy of the model. The model achieved a solution with a completion time of 310 days, costs amounting to 5,247,775 â‚ș, 88.036% quality, and 77.338% SI

    Effect of different protein levels on, testicular parameters and semen quality in Kivircik ram lambs during pubertal development

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    The aim of this study was to determine the effects of different protein levels on, testicular parameters and semen quality in Kivircik ram lambs during pubertal development. Two experimental groups were formed. Following weaning, crude protein (CP) were 12% CP in group I (low protein diet) and 18% CP in group II (high protein diet). Measurements of live weight and testicular characteristics were performed in 20 days intervals starting from 115 days up to 195 days of age. There was an increase in semen volume, spermatozoa concentration and the percentage of progressively motile sperm in both groups between 135 and 195 days of age. Group I had significantly higher semen volume on day 175 (P<0.05). Furthermore, spermatozoa concentration were higher in group I than those in group II on days 155 and 175 (P<0.05). Values of live weight, testicular diameter, testicular circumference, testicular length and testicular volume of ram lambs in group II (high protein diet) were higher than those in group I (low protein diet). Testicular length and testicular volume of group II were significantly higher than those of group I on day 195 (P<0.05). Live weight and testicular characteristics of ram lambs fed with high protein diet were affected positively during pubertal development. However, it was observed that feeding with high protein diet had negative effect on semen characteristics by impaired thermoregulation mechanism and spermatogenesis in testicles because of excessive fat accumulation in scrotum

    A Brief History of Web Crawlers

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    Web crawlers visit internet applications, collect data, and learn about new web pages from visited pages. Web crawlers have a long and interesting history. Early web crawlers collected statistics about the web. In addition to collecting statistics about the web and indexing the applications for search engines, modern crawlers can be used to perform accessibility and vulnerability checks on the application. Quick expansion of the web, and the complexity added to web applications have made the process of crawling a very challenging one. Throughout the history of web crawling many researchers and industrial groups addressed different issues and challenges that web crawlers face. Different solutions have been proposed to reduce the time and cost of crawling. Performing an exhaustive crawl is a challenging question. Additionally capturing the model of a modern web application and extracting data from it automatically is another open question. What follows is a brief history of different technique and algorithms used from the early days of crawling up to the recent days. We introduce criteria to evaluate the relative performance of web crawlers. Based on these criteria we plot the evolution of web crawlers and compare their performanc

    Effect of different protein levels on, testicular parameters and semen quality in Kivircik ram lambs during pubertal development

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    The aim of this study was to determine the effects of different protein levels on, testicular parameters and semen quality in Kivircik ram lambs during pubertal development. Two experimental groups were formed. Following weaning, crude protein (CP) were 12% CP in group I (low protein diet) and 18% CP in group II (high protein diet). Measurements of live weight and testicular characteristics were performed in 20 days intervals starting from 115 days up to 195 days of age. There was an increase in semen volume, spermatozoa concentration and the percentage of progressively motile sperm in both groups between 135 and 195 days of age. Group I had significantly higher semen volume on day 175 (P<0.05). Furthermore, spermatozoa concentration were higher in group I than those in group II on days 155 and 175 (P<0.05). Values of live weight, testicular diameter, testicular circumference, testicular length and testicular volume of ram lambs in group II (high protein diet) were higher than those in group I (low protein diet). Testicular length and testicular volume of group II were significantly higher than those of group I on day 195 (P<0.05). Live weight and testicular characteristics of ram lambs fed with high protein diet were affected positively during pubertal development. However, it was observed that feeding with high protein diet had negative effect on semen characteristics by impaired thermoregulation mechanism and spermatogenesis in testicles because of excessive fat accumulation in scrotum

    An Integrated Methodology for Supplier Selection under the Presence of Vagueness: A Case in Banking Sector, Turkey

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    A supplier selection process mainly involves evaluation of different alternative suppliers based on different criteria. This process can be handled as a combination of the customer needs and the technical requirements. Also customers can be considered as the companies to purchase the suppliers’ technical expertise. Hence, this kind of relationship can be analyzed as a house of quality model typical of quality function deployment (QFD). This paper develops a supplier evaluation approach based on the analytic network process (ANP), QFD, and the technique for order performance by similarity to ideal solution (TOPSIS) methods to help an investment bank in Turkey as a real world application. Fuzzy logic is used to capture the vagueness in people’s verbal assessments. In the first phase, matrices used to define the importance of the supplier selection criteria and the technical requirements are calculated with the fuzzy ANP method. The technical requirements and the criteria are combined in the house of quality to evaluate the relationship between them. In the second phase, fuzzy TOPSIS is used to rank the suppliers based on the weighted criteria obtained from the first phase. The study was followed by the sensitivity analysis of the results

    Disability-sensitive occupational risk assessment

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    This paper presents the findings of an ongoing National Institute for Research and Development in Occupational Safety “Alexandru Darabont” INCDPM project developed in collaborations with BAUM Engineering SRL that addresses the occupational safety issues related to workers with disabilities, with emphasis on disability-sensitive risk assessment. In our project we developed a method of occupational risk assessment that is disability-sensitive, in order to help employer and safety professionals. The disability-sensitive risk assessment method will identify all the risk factors in the system that can be the ultimate cause of injury and/or professional illness by means of predefined control lists and quantifying the risk based on the combination of gravity and probability of risk factor manifestation. The main steps in applying the method will be: establishment of the assessment team; description of the analysed system (workplace, installation); identification of risk factors in the system; assessment of the risks of occupational injury and illness; prioritizing risks and establishing prevention priorities; proposing prevention measures. Every step mentioned before will be disability-sensitive, taking account of individual workers’ differences and avoiding discrimination at the same time

    Development, test and comparison of two Multiple Criteria Decision Analysis(MCDA) models: A case of healthcare infrastructure location

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    When planning a new development, location decisions have always been a major issue. This paper examines and compares two modelling methods used to inform a healthcare infrastructure location decision. Two Multiple Criteria Decision Analysis (MCDA) models were developed to support the optimisation of this decision-making process, within a National Health Service (NHS) organisation, in the UK. The proposed model structure is based on seven criteria (environment and safety, size, total cost, accessibility, design, risks and population profile) and 28 sub-criteria. First, Evidential Reasoning (ER) was used to solve the model, then, the processes and results were compared with the Analytical Hierarchy Process (AHP). It was established that using ER or AHP led to the same solutions. However, the scores between the alternatives were significantly different; which impacted the stakeholders‟ decision-making. As the processes differ according to the model selected, ER or AHP, it is relevant to establish the practical and managerial implications for selecting one model or the other and providing evidence of which models best fit this specific environment. To achieve an optimum operational decision it is argued, in this study, that the most transparent and robust framework is achieved by merging ER process with the pair-wise comparison, an element of AHP. This paper makes a defined contribution by developing and examining the use of MCDA models, to rationalise new healthcare infrastructure location, with the proposed model to be used for future decision. Moreover, very few studies comparing different MCDA techniques were found, this study results enable practitioners to consider even further the modelling characteristics to ensure the development of a reliable framework, even if this means applying a hybrid approach

    Causes of changes in carotid intima-media thickness: a literature review

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    An Aggregate Production Planning Strategy Selection Methodology based on Linear Physical Programming

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    In this paper, a multi-objective model for aggregate production planning is presented which includes two objectives: (1) minimized cost and (2) minimized effect on the workforce motivation level caused by hire/layoff decisions. Then, six strategies are considered and the most appropriate one is determined to structure the plan. These strategies are set the regular time production quantities in a certain value which is unique for each. A preference based optimization method called Linear Physical Programming (LPP) is used to solve the model. A forecasting phase which chooses the convenient method to forecast the demand for planning horizon is embedded to study in addition to application of LPP to an APP model as another key contribution of this paper
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