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For estimating an unknown parameter θ, we introduce and motivate the use of balanced loss functions of the form Lr, w, d0(q, d)=wr(d0, d)+ (1-w) r(q, d){L_{\rho, \omega, \delta_0}(\theta, \delta)=\omega \rho(\delta_0, \delta)+ (1-\omega) \rho(\theta, \delta)}, as well as the weighted version q(q) Lr, w, d0(q, d){q(\theta) L_{\rho, \omega, \delta_0}(\theta, \delta)}, where ρ(θ, δ) is an arbitrary loss function, δ 0 is a chosen a priori “target” estimator of q, w ? [0,1){\theta, \omega \in[0,1)}, and q(·) is a positive weight function. we develop Bayesian estimators under Lr, w, d0{L_{\rho, \omega, \delta_0}} with ω > 0 by relating such estimators to Bayesian solutions under Lr, w, d0{L_{\rho, \omega, \delta_0}} with ω = 0. Illustrations are given for various choices of ρ, such as absolute value, entropy, linex, and squared error type losses. Finally, under various robust Bayesian analysis criteria including posterior regret gamma-minimaxity, conditional gamma-minimaxity, and most stable, we establish explicit connections between optimal actions derived under balanced and unbalanced losses.  相似文献   
3.
This study presents an investigation of enhancing the capability of the Scatter Search (SS) metaheuristic in guiding the search effectively toward elite solutions. Generally, SS generates a population of random initial solutions and systematically selects a set of diverse and elite solutions as a reference set for guiding the search. The work focuses on three strategies that may have an impact on the performance of SS. These are: explicit solutions combination, dynamic memory update, and systematic search re-initialization. First, the original SS is applied. Second, we propose two versions of the SS (V1 and V2) with different strategies. In contrast to the original SS, SSV1 and SSV2 use the quality and diversity of solutions to create and update the memory, to perform solutions combinations, and to update the search. The differences between SSV1 and SSV2 is that SSV1 employs the hill climbing routine twice whilst SSV2 employs hill climbing and iterated local search method. In addition, SSV1 combines all pairs (of quality and diverse solutions) from the RefSet whilst SSV2 combines only one pair. Both SSV1 and SSV2 update the RefSet dynamically rather than static (as in the original SS), where, whenever a better quality or more diverse solution is found, the worst solution in RefSet is replaced by the new solution. SSV1 and SSV2 employ diversification generation method twice to re-initialize the search. The performance of the SS is tested on three benchmark post-enrolment course timetabling problems. The results had shown that SSV2 performs better than the original SS and SSV1 (in terms of solution’s quality and computational time). It clearly demonstrates the effectiveness of using dynamic memory update, systematic search re-initialization, and combining only one pair of elite solutions. Apart from that, SSV1 and SSV2 can produce good quality solutions (comparable with other approaches), and outperforms some approaches reported in the literature (on some instances with regards to the tested datasets). Moreover, the study shows that by combining (simple crossover) only one pair of elite solutions in each RefSet update, and updating the memory dynamically, the computational time is reduced.  相似文献   
4.
In this paper, we investigate the effect of a cold standby component on the mean residual life (MRL) of a system. When the system fails, a cold standby component is immediately put in operation. We particularly focus on the coherent systems in which, after putting the standby component into operation, the failure of the system is due to the next component failure. For these systems, we define MRL functions and obtain their explicit expressions. Also some stochastic ordering results are provided. Such systems include k-out-of-n systems. Hence, our results extend some results in literature.  相似文献   
5.
Abstract

Even though supply chain agility (SCA) has been considered an essential concept in supply chain management (SCM) research, the way it is experienced and manifested, especially by small and medium-sized enterprises (SMEs), has received much less attention. Our purpose is to focus on SME organisational vulnerabilities in the context of increased environmental uncertainty, and explore how SCA is developed and applied by SMEs amid their vulnerabilities. By relying on insights from comparative case studies of three British SMEs, we examine SME SCA as an acclimatisation process and delve into SMEs’ experiences of facing environmental uncertainty while developing and applying SCA. Our findings highlight that organisational attitudes underlie how SMEs perceive environmental uncertainty, tackle organisational vulnerabilities and develop SCA as an acclimatisation process. Our findings also reveal that resource constraints, supply chain relationships, interorganisational power dynamics, and access to information play important roles in developing SCA.  相似文献   
6.
It is well known that the testing of zero variance components is a non-standard problem since the null hypothesis is on the boundary of the parameter space. The usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold because of this null hypothesis. To circumvent this difficulty in balanced linear growth curve models, we introduce an appropriate test statistic and suggest a permutation procedure to approximate its finite-sample distribution. The proposed test alleviates the necessity of any distributional assumptions for the random effects and errors and can easily be applied for testing multiple variance components. Our simulation studies show that the proposed test has Type I error rate close to the nominal level. The power of the proposed test is also compared with the likelihood ratio test in the simulations. An application on data from an orthodontic study is presented and discussed.  相似文献   
7.
Through the investigation of kolberi (cross-border labor), this paper sheds light on the state’s policy of de-development (or internal colonialization) of the Kurdish region (known as Rojhelat) in Iran. While the most dangerous form of labor, kolberi has become a dominant employment opportunity for Rojhelat Kurds in the last decade. There are no Iranian state laws criminalizing kolberi, and yet those laborers die on a regular basis—being shot or thrown off mountain cliffs by the state forces, stepping into minefields, and so forth. Nevertheless, there is not a single scholarly paper on this subject. Using the mixed methods research approach, our study analyzes the existing data along with in-depth interviews with 20 people who are currently engaged in kolberi to contextualize this understudied phenomenon. Our finding demonstrates that kolberi is a direct outcome of a uni-ethno-religious policies of development and part and parcel of the state's Perso-Shi‘ification strategy in Kurdistan. Therefore, kolberi is more of a political phenomenon than an economic one.  相似文献   
8.
This note is an answer to a previous model on conformity in public goods contributions developed by Carpenter (2004), where a population evolution is allowed according to the standard replicator dynamic (Taylor and Jonker, 1978, Maynard Smith, 1982). To confirm his theoretical prediction, Carpenter developed an experiment showing that free riding actually grows faster when agents have the information necessary to conform. The model and the experiment are, however, inherently different, for the time scales of the model are not able to capture the short run convergence of behavior in the experimental laboratory.We here present a model of conformity which offers the same laboratory results as Carpenter without resorting to evolutionary models, and also gives agents the chance to adopt different strategies implying various levels of cooperation.  相似文献   
9.
Muslims constitute about 14% population of India and are the largest religious minority community spread over the length and breadth of the country. The minority community in question has been relegated to the lowest socio-economic stratum in Indian society especially after the partition and independence of the country. However, in the state of Jammu and Kashmir, Muslims are in majority constituting about 67% population of the state. In the current study, the Concentration Index of Muslim population, variation in literacy rate and work participation, occupational structure across region and religion, as well as the interrelationship between concentration of Muslim population, literacy rate and work participation in Jammu and Kashmir has been explored and explained. The present study is based upon secondary information obtained from Census 2001 and is also supplemented with government reports, published work wherever necessary. As far as share of Muslims in the sphere of education and employment in the state of Jammu and Kashmir is concerned, they have reported lower share among the population of literates, category of other workers and higher share in the occupational category of cultivators, agricultural labourers, household industry workers and non-workers in comparison to all religious groups. This means that despite being in majority, their situation is similar to their co-religionists at the all India level.  相似文献   
10.
This study aims to identify the challenges and approaches to improve a multicultural competency among teachers in multi-ethnic schools environment based on school leaders’ perspective. Data collection method used in this study is qualitative method. A total of nine school leaders from the states of Kedah, Penang, and Perak were included in the interview session. The results of this study show that the challenges faced by teachers in practicing the multicultural competency are lack of experience toward cultural diversity. A late exposure to cultural diversity makes it difficult for teachers to accept and adapt in a multi-ethnic school environment. The approaches suggested by school leaders to improve the multicultural competency are as follows: (1) Courses on cultural diversity should be organized to enhance the knowledge about cultural diversity; (2) the development of more open and better policy for education system in Malaysia in order to prepare teachers with a higher multicultural competency for teaching students from diverse ethnic and cultural groups; (3) an early exposure to cultural diversity in order to increase the multicultural competency, especially during teaching practicum.  相似文献   
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