5,240 research outputs found

    Implementation of a fixing strategy and parallelization in a recent global optimization method

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    Electromagnetism-like Mechanism (EM) heuristic is a population-based stochastic global optimization method inspired by the attraction-repulsion mechanism of the electromagnetism theory. EM was originally proposed for solving continuous global optimization problems with bound constraints and it has been shown that the algorithm performs quite well compared to some other global optimization methods. In this work, we propose two extensions to improve the performance of the original algorithm: First, we introduce a fixing strategy that provides a mechanism for not being trapped in local minima, and thus, improves the effectiveness of the search. Second, we use the proposed fixing strategy to parallelize the algorithm and utilize a cooperative parallel search on the solution space. We then evaluate the performance of our study under three criteria: the quality of the solutions, the number of function evaluations and the number of local minima obtained. Test problems are generated by an algorithm suggested in the literature that builds test problems with varying degrees of difficulty. Finally, we benchmark our results with that of the Knitro solver with the multistart option set

    A symmetric rank-one Quasi-Newton line-search method using negative curvature directions

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    We propose a quasi-Newton line-search method that uses negative curvature directions for solving unconstrained optimization problems. In this method, the symmetric rank-one (SR1) rule is used to update the Hessian approximation. The SR1 update rule is known to have a good numerical performance; however, it does not guarantee positive definiteness of the updated matrix. We first discuss the details of the proposed algorithm and then concentrate on its numerical efficiency. Our extensive computational study shows the potential of the proposed method from different angles, such as; its second order convergence behavior, its exceeding performance when compared to two other existing packages, and its computation profile illustrating the possible bottlenecks in the execution time. We then conclude the paper with the convergence analysis of the proposed method

    Proceedings of the Conference on Human and Economic Resources

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    The global marketplace consists of an increasingly complex arena of competitors within a rapidly changing international environment. New companies are formed on a daily basis, from small businesses to Internet-based operations, to expanding global conglomerates originating from major takeovers and mergers. In the face of these sophisticated and cluttered market conditions, firms try to be heard. They attempt to speak with clear voices about the natures of their operations and the benefits associated with the firm’s goods and services. With so many choices available, and so many media bombarding potential customers with messages, it is vital that what should be communicated is reaching buyers in a clear and consistent manner. External customers are influenced by the internal promise deliverers: the employees, channel partners, customer service personnel, packing and delivery people. Marketing can help by working with human resources departments to identify the key elements in employee motivation, including the effect of incentives and the development of training and improvement programs. This paper explores the impact of integrated marketing communications (IMC) programs in enhancing manager and employee performance and so productivity. From a managerial context, response to this apparently cluttered and amorphous marketing environment has led many organizations to desirable integration of their communications efforts under the umbrella of one strategic marketing communications function - namely integrated marketing communications. The logic of this strategic move would seem to rest partly on assumptions concerning the desire for organizational influence of consumer perceptions. Manager performance and development is possibly an overlooked part of an IMC program. Effective marketing departments and advertising agencies must develop pipelines of new, talented creatives, media buyers, promotions managers, database Web masters, and others in order to succeed in the long term. Also, new people must be trained and prepared for promotions for more important roles over time. Employee performance attitudes reflect morale within the marketing department and also relations with other departments and groups. An effective IMC plan consists of building bridges with other internal departments so that everyone is aware of the thrust and theme of the program. Satisfied and positive employees are more likely to help the firm promote its image.Integrated Marketing Communications Programs, Manager and Employee Performance

    An Inexact Successive Quadratic Approximation Method for Convex L-1 Regularized Optimization

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    We study a Newton-like method for the minimization of an objective function that is the sum of a smooth convex function and an l-1 regularization term. This method, which is sometimes referred to in the literature as a proximal Newton method, computes a step by minimizing a piecewise quadratic model of the objective function. In order to make this approach efficient in practice, it is imperative to perform this inner minimization inexactly. In this paper, we give inexactness conditions that guarantee global convergence and that can be used to control the local rate of convergence of the iteration. Our inexactness conditions are based on a semi-smooth function that represents a (continuous) measure of the optimality conditions of the problem, and that embodies the soft-thresholding iteration. We give careful consideration to the algorithm employed for the inner minimization, and report numerical results on two test sets originating in machine learning

    Classification of Turkish extra virgin olive oils by a SAW detector electronic nose

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    An electronic nose (e-nose), in combination with chemometrics, has been used to classify the cultivar, harvest year, and geographical origin of economically important Turkish extra virgin olive oils. The aroma fingerprints of the eight different olive oil samples [Memecik (M), Erkence (E), Gemlik (G), Ayvalik (A), Domat (D), Nizip (N), Gemlik-Edremit (GE), Ayvalik-Edremit (AE)] were obtained using an e-nose consisting a surface acoustic wave detector. Data were analyzed by principal component analysis (PCA) and discriminant function analysis (DFA). Classification of cultivars using PCA revealed that A class model was correctly discriminated from N in two harvest years. The DFA classified 100 and 97% of the samples correctly according to the cultivar in the 1st and 2nd harvest years, respectively. Successful separation among the harvest years and geographical origins were obtained. Sensory analyses were performed for determining the differences in the geographical origin of the olive oils and the preferences of the panelists. The panelists could not detect the differences among olive oils from two different regions. The cultivar, harvest year, and geographical origin of extra virgin olive oils could be discriminated successfully by the e-nose.Scientific and Technical Research Council of Turkey (104O333

    Social Participation of Turkish and Arabic Immigrants in the Neighborhood: Case Study of Moabit West, Berlin

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    Social participation of immigrants in district activities and local planning processes is given significance in Germany. It has become an important issue with the introduction of Neighborhood Management concept in the 1990s. This concept deals with districts which have a considerable percentage of low-income, unemployed, low-educated,immigrant population and social help beneficiaries. Immigrants are usually seen as the cause of the problems in those areas by the authorities since they are not integrated into the host societyand to the other immigrant groups. Since the 1990s, they have started to be seen as potential solution to the problems by means of an active social participation in their neighborhood. Desired level of social participation, however, has not been reached due to a number of reasons although there are a few immigrants who take part in social, cultural and planning activities in their district.The aim of this article is to outline the reasons of low participation rates, motivations of the participant immigrants and the forms of participation among Turkish and Arabic immigrantsin a neighborhood of Berlin, Moabit West, based on in-dept interviews made with both nonparticipant and participant immigrants and with some immigrant associations. The field research was carried out in June 2005, within the framework of the project ‘Immigrants in the City’. The reasons of low participation which were found as a result of this research study are language deficiency, different cultural understandings of participation, looking for concrete results of participatory actions and lack of information. The participant immigrants are motivated to solve the problems in the district and to change it, to increase integration of the immigrant youth into the society and of the immigrants, to the established society. Lastly, participant immigrants usually take part in street festivals and youth social work, and in immigrant associations instead of German ones
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