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Publication Metadata only “Beware the young doctor and the old barber”: development and validation of a job age-type spectrum(Elsevier, 2021) Reeves, Michael Dennis; Fritzsche, Barbara Ann; Smith, Nicholas Anthony; Ng, Yin Lu; Department of Business Administration; Marcus, Justin; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 124653Taking a worker-centric approach, with evidence based on the experiences of working individuals, the current study examines the age-related stereotypes of jobs, the characteristics of age-stereotyped jobs, and the consequences of occupying them. In Study 1, we utilize samples of working adults from the US, Turkey, and Malaysia to establish validation evidence for a spectrum of 160 jobs (n = 123 raters per job). Study 1 findings indicate that entry-level jobs and jobs requiring manual labor or the use of technology are younger-typed, whereas senior level jobs and jobs requiring large investments in training or education are older-typed. The age-typing of jobs was found to be similar across countries for the vast majority of jobs. We then provide criterion validity evidence in Study 2, by testing the interactive effects of chronological age, job age-type, and sex on psychological age and perceived age and sex discrimination across samples of workers from these same three countries (n = 1469). Results upheld theoretical predictions based upon career timetables theory, prototype matching theory, and intersectional salience of ageism theory. The interactive effects of chronological age and job age-type were stronger for women than for men; the hypothesized patterns of effects were overall consistent for women but not for men.Publication Metadata only A bicriteria approach to the two-machine flow shop scheduling problem(Elsevier Science Bv, 1999) N/A; Department of Business Administration; Department of Business Administration; Sayın, Serpil; Karabatı, Selçuk; Faculty Member; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; College of Administrative Sciences and Economics; 6755; 38819In this paper we address the problem of minimizing makespan and sum of completion times simultaneously in a two-machine flow shop environment. We formulate the problem as a bicriteria scheduling problem, and develop a branch-and-bound procedure that iteratively solves restricted single objective scheduling problems until the set of efficient solutions is completely enumerated. We report computational results, and explore certain properties of the set of efficient solutions. We then discuss their implications for the Decision Maker.Publication Metadata only A bilevel fixed charge location model for facilities under imminent attack(Pergamon-Elsevier Science Ltd, 2012) Aras, Necati; Department of Business Administration; Aksen, Deniz; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 40308We investigate a bilevel fixed charge facility location problem for a system planner (the defender) who has to provide public service to customers. The defender cannot dictate customer-facility assignments since the customers pick their facility of choice according to its proximity. Thus, each facility must have sufficient capacity installed to accommodate all customers for whom it is the closest one. Facilities can be opened either in the protected or unprotected mode. Protection immunizes against an attacker who is capable of destroying at most r unprotected facilities in the worst-case scenario. Partial protection or interdiction is not possible. The defender selects facility sites from m candidate locations which have different costs. The attacker is assumed to know the unprotected facilities with certainty. He makes his interdiction plan so as to maximize the total post-attack cost incurred by the defender. If a facility has been interdicted, its customers are reallocated to the closest available facilities making capacity expansion necessary. The problem is formulated as a static Stackelberg game between the defender (leader) and the attacker (follower). Two solution methods are proposed. The first is a tabu search heuristic where a hash function calculates and records the hash values of all visited solutions for the purpose of avoiding cycling. The second is a sequential method in which the location and protection decisions are separated. Both methods are tested on 60 randomly generated instances in which m ranges from 10 to 30, and r varies between 1 and 3. The solutions are further validated by means of an exhaustive search algorithm. Test results show that the defender's facility opening plan is sensitive to the protection and distance costs.Publication Metadata only A Bilevel p-median model for the planning and protection of critical facilities(Springer, 2013) Aras, Necati; Piyade, Nuray; Department of Business Administration; Aksen, Deniz; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 40308The bilevel p-median problem for the planning and protection of critical facilities involves a static Stackelberg game between a system planner (defender) and a potential attacker. The system planner determines firstly where to open p critical service facilities, and secondly which of them to protect with a limited protection budget. Following this twofold action, the attacker decides which facilities to interdict simultaneously, where the maximum number of interdictions is fixed. Partial protection or interdiction of a facility is not possible. Both the defender's and the attacker's actions have deterministic outcome; i.e., once protected, a facility becomes completely immune to interdiction, and an attack on an unprotected facility destroys it beyond repair. Moreover, the attacker has perfect information about the location and protection status of facilities; hence he would never attack a protected facility. We formulate a bilevel integer program (BIP) for this problem, in which the defender takes on the leader's role and the attacker acts as the follower. We propose and compare three different methods to solve the BIP. The first method is an optimal exhaustive search algorithm with exponential time complexity. The second one is a two-phase tabu search heuristic developed to overcome the first method's impracticality on large-sized problem instances. Finally, the third one is a sequential solution method in which the defender's location and protection decisions are separated. The efficiency of these three methods is extensively tested on 75 randomly generated instances each with two budget levels. The results show that protection budget plays a significant role in maintaining the service accessibility of critical facilities in the worst-case interdiction scenario.Publication Metadata only A bilevel partial interdiction problem with capacitated facilities and demand outsourcing(Elsevier, 2014) Akça, Sema Şengul; Aras, Necati; Department of Business Administration; Aksen, Deniz; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 40308In this paper, partial facility interdiction decisions are integrated for the first time into a median type network interdiction problem with capacitated facilities and outsourcing option. The problem is modeled as a static Stackelberg game between an intelligent attacker and a defender. The attacker's (leader's) objective is to cause the maximum (worst-case) disruption in an existing service network subject to an interdiction budget. On the other hand, the defender (follower) is responsible for satisfying the demand of all customers while minimizing the total demand-weighted transportation and outsourcing cost in the wake of the worst-case attack. She should consider the capacity reduction at the interdicted facilities where the number of interdictions cannot be known a priori, but depends on the attacker's budget allocation. We propose two different methods to solve this bilevel programming problem. The first one is a progressive grid search which is not viable on large sized instances. The second one is a multi-start simplex search heuristic developed to overcome the exponential time complexity of the first method. We also use an exhaustive search method to solve all combinations of full interdiction to assess the advantage of partial interdiction for the attacker. The test results suggest that under the partial interdiction approach the attacker can achieve a better utilization of his limited resources.Publication Metadata only A bourdieuan relational perspective for entrepreneurship research(Wiley, 2014) Tatli, Ahu; Vassilopoulou, Joana; Forson, Cynthia; Slutskaya, Natasha; Department of Business Administration; Özbilgin, Mustafa; Other; Department of Business Administration; College of Administrative Sciences and Economics; N/AIn this paper, we illustrate the possibilities a relational perspective offers for overcoming the dominant dichotomies (e.g., qualitative versus quantitative, agency versus structure) that exist in the study of entrepreneurial phenomena. Relational perspective is an approach to research that allows the exploration of a phenomenon, such as entrepreneurship, as irreducibly interconnected sets of relationships. We demonstrate how Pierre Bourdieu's concepts may be mobilized to offer an exemplary toolkit for a relational perspective in entrepreneurship research.Publication Metadata only A construal level account of the impact of religion and god on prosociality(Sage, 2020) N/A; N/A; Department of Business Administration; Canlı, Zeynep Gürhan; Karataş, Mustafa; PhD Student; Faculty Member; Department of Business Administration; Graduate School of Business; College of Administrative Sciences and Economics; N/A; 16135This research shows that the two most prevalent religious constructs-God and religion-differentially impact cognition. Activating thoughts about God (vs. religion) induces a relatively more abstract (vs. concrete) mindset (Studies 1a-1c). Consequently, time donation intentions (Study 2) and actual monetary donations (Study 3) after a God (vs. religion) prime increase when people are presented an abstractly (vs. concretely) framed donation appeal. Similarly, people donate more money to distant (vs. close) donation targets, which are construed relatively abstractly (vs. concretely), when a religious speech activates predominantly God-specific (vs. religion-specific) thoughts (Study 4). These effects are mediated by "feeling right" under construal level fit (Study 3). Overall, this research significantly advances extant knowledge on religious cognition and past research on the link between religion and prosociality.Publication Metadata only A decomposition model for continuous materials flow production systems(Taylor & Francis, 1997) Yeralan, Sencer; Department of Business Administration; N/A; Tan, Barış; Faculty Member; N/A; Department of Business Administration; College of Administrative Sciences and Economics; N/A; 28600; N/AThis study presents a general and flexible decomposition method for continuous materials flow production systems. The decomposition method uses the station model developed in the first part of this study (Yeralan and Tan 1997). The decomposition method is an iterative method. At each iteration the input and output processes of the station model are matched to the most recent solutions of the adjacent stations. The procedure terminates when the solutions converge and the conservation of materials flow is satisfied. The decomposition method does not alter the station parameters such as the breakdown, repair, and service rates. This method can be used to analyse a wide variety of production systems built from heterogeneous stations. The properties of the decomposition method are studied for the series arrangement of workstations. The convergence and uniqueness of the decomposition method are discussed. The method is compared to other approximation methods. The complexity of the decomposition method is empirically investigated and is shown to be in the order of N-2 where N is the number of stations in the line, irrespective of the buffer capacities.Publication Metadata only A game theoretic model and empirical analysis of spammer strategies(Conference on Email and Anti-Spam, CEAS, 2010) Parameswaran, Manoj; Rui, Huaxia; Whinston, Andrew B.; Department of Business Administration; Sayın, Serpil; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 6755Network security problems are deteriorating worldwide, and can potentially undermine the growth of the digital economy and imperil the multitude of innovations that have been a significant driver of economic growth as well as providing increased services to individuals, businesses, and governments. The emergence of botnets as a powerful force undermining security has raised new and important issues. In particular, the difficulty of detection, elimination and prevention of botnets or spam caused thereof on an absolute scale using computing technologies alone have focused attention on studying behavior patterns of botnets and spammers, to help devise better countermeasures. This paper has two objectives; first to introduce a theoretical modeling approach to spammer behavior and derivation of the model, and second, to compare some of the derivations with data that has been collected from blocklist organizations. By making inferences about the blocklist rules, the spammer can strategize to maximize the amount of spam sent, and we find evidence of spammers using multiple strategies. The blocklist can achieve reduction of spam by investigating longer history of a node's behavior instead of focusing on detection alone. While some of the derivations seem consistent with the data there is considerable room for modification and extension of the modeling approach. The paper concludes with suggestion for the extension of the model.Publication Metadata only A location-routing problem for the conversion to the "click-and-mortar" retailing: the static case(Elsevier, 2008) Altınkemer, Kemal; Department of Business Administration; Aksen, Deniz; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 40308The static conversion from brick-and-mortar retailing to the hybrid click-and-mortar business model is studied from the perspective of distribution logistics. Retailers run warehouses and brick-and-mortar stores to meet the demand of their walk-in customers. When they decide to operate on the Web as an e-tailer, also click-and-mortar stores are needed which can serve both walk-in and online customers. While the distance between home and the nearest open store is used as a proxy measure for walk-in customers, a quality of service (QoS) guarantee for online customers is timely delivery of their orders. We describe and solve a static location-routing based problem for companies that embrace the clicks-and-bricks strategy in their retail operations. An augmented Lagrangian relaxation method embedded in a subgradient optimization procedure generates lower bounds, whereas a heuristic method finds feasible solutions. The performance of the Lagrangian-based solution method is tested on a number of randomly generated test problems.