A three-stage assembly flow shop scheduling problem with blocking and sequence-dependent set up times

This paper considers a three-stage assembly flowshop scheduling problem with sequence-dependent setup times at the first stage and blocking times between each stage in such a way that the weighted mean completion time and makespan are minimized. Obtaining an optimal solution for this type of complex, large-sized problem in reasonable computational time using traditional approaches or optimization tools is extremely difficult. Thus, this paper proposes a meta-heuristic method based on simulated annealing (SA) in order to solve the given problem. Finally, the computational results are shown and compared in order to show the efficiency of our proposed SA

Evolution of Communities in the Medical Sciences: Evidence from the Medical Words Network

BACKGROUND: Classification of medical sciences into its sub-branches is crucial for optimum administration of healthcare and specialty training. Due to the rapid and continuous evolution of medical sciences, development of unbiased tools for monitoring the evolution of medical disciplines is required. METHODOLOGY/PRINCIPAL FINDINGS: Network analysis was used to explore how the medical sciences have evolved between 1980 and 2015 based on the shared words contained in more than 9 million PubMed abstracts. The k-clique percolation method was used to extract local research communities within the network. Analysis of the shared vocabulary in research papers reflects the trends of collaboration and splintering among different disciplines in medicine. Our model identifies distinct communities within each discipline that preferentially collaborate with other communities within other domains of specialty, and overturns some common perceptions. CONCLUSIONS/SIGNIFICANCE: Our analysis provides a tool to assess growth, merging, splitting and contraction of research communities and can thereby serve as a guide to inform policymakers about funding and training in healthcare

RACE AND RAC(IAL)ISM, THE POLITICS OF PEACE AND FRIENDSHIP IN A LIBERAL CONSTITUTION: NEW REFLECTIONS OR OLD WINE IN NEW BOTTLES? A CRITICAL ANALYSIS

The context of this article is a two-part investigative documentary on ‘race’ as an enduring fault line in South African politics on etv’s 3rd degree (2010) programme as well as a true-life drama, For One Night (2006)3 which explores a 30-year old ‘tradition’ of racially segregated school dances in southern American states. The events detailed in both shows resonate strongly with the essence of this article in that they both publicly engage with and challenge pre-existing ideas about race and racialism and depict ordinary citizens having to be confronted by the ongoing uneasiness of race in their daily lives. On 3rd degree, students at University of the Free State (UFS), spoke honestly about the challenges of racism they face at UFS, on campus and in the residences. On For One Night, conservative white families had to come to terms with the possibility of their children mingling with their black counterparts at the traditionally segregated school dance for the first time in 30 years

A Comparison of the Shared Activities With the Spouse Between Men and Women: Similarities and Differences

Given the importance of joint activities in couples’ relationships and the involved gender differences, this article aims to investigate shared activities with the spouse in different aspects of everyday life and their determinants in married men and women in Tehran, the capital of Iran. Through multi-stage cluster sampling, 1,736 samples were selected from 50 districts of Tehran. A cross-sectional survey was conducted with a questionnaire instrument. Five dimensions (social contacts, spending time outdoors, spending time indoors, talking with the spouse, and money spending) were extracted from factor analysis. The results indicate that the majority of men and women have joint activities in everyday life. Compared to men, women gain more marital happiness from joint activities, but they reported fewer in some dimensions. The spousal similarity is one of the major determinants of the shared activities with the spouse, both in men and women. Education is among the factors that increase and income difference between the factors that decrease have more effective in women than men. Spousal similarity and gender attitudes have the highest share in explaining shared activities while the share of components related to life cycle is lower. Traditional gender attitudes as a reducing factor have the greatest impact on men. In general, we can say despite the similarities, shared activities with the spouse are not the same for men and women in different aspects. The explanatory power of the model is greater for women than men. It is influenced by various factors, and the impact of these factors is not the same for both sexes

Error and Attack Tolerance of Public Transportation Networks: A Temporal Networks Approach

The behaviour of complex networks under attack provides insight into their internal structure. Furthermore, advances in methods for analysing temporal networks have enabled us to perform more detailed modelling of a certain subset of dynamic complex systems specially since frequency of events and temporal correlations play a role in dynamics of the system. In this report, the temporal network approach for study of robustness is applied to public transportation networks. The focus is on providing a set of tools to model different scenarios of attack and random failure, and processing the results with or without taking into account the origin-destination demand matrix frequently used in transportation network studies. The results of the robustness analysis on temporal representation of public transport networks illustrate the distribution of accessibility and travel time after an attack or error and how it changes when more routes are removed. Furthermore we see that two methods of attack, one based on temporal betweenness centrality and one based on nominal capacity of routes, have a higher effect on increasing delays while attack methods based on centrality of routes in a static aggregated network do not perform any better than randomly removing routes

POST-APARTHEID REFLECTIONS ON CRITIQUE, TRANSFORMATION AND REFUSAL

In this article I engage with the notion of refusal, as introduced by Karin Van Marle, to post-apartheid jurisprudence as a way through which to think of life, death, law and politics against the backdrop of poverty, social misery, disease, oppression and prejudice. She proposes that we consider refusal firstly as a possible mode of critical thinking and theorising but ultimately also as an alternative approach to law and jurisprudence. For Van Marle, what lies at the heart of refusal is the ‘idea of unexpectedness that breaks with the formality and predictability of law’ — an unexpectedness that could disclose new directions for thinking about and doing law

Restoring dynamic properties of damaged buildings using pole assignment control method

In this paper pole assignment control method is used to modify dynamic properties of damaged buildings. Since the eigenvalues of open-loop system, known as poles, are related to the dynamic properties of the system, damage causes changes in their values. In terms of pole assignment, a controller will modify dynamic properties of damaged structure by moving the eigenvalues to their initial place. Using the proposed gain matrix calculation algorithm and restoring the initial eigenvalues, dynamic properties of undamaged building, which have been lost due to damage, can be restored. When feedback controller restores all the eigenvalues, damaged elements and connections can be verified from the large control forces concentrated in the nodes of damaged elements. The algorithm also represents a new approach for partial pole assignment and the effect of restoring some undesired eigenvalues can be studied individually. For numerical simulation, a typical ten-story moment frame building is employed which has experienced some damages during the 1971 Newhall earthquake. Three states of damage are defined for the finite element model of the building to consider damage in elements and connections

Calibration of Separate Window Model Factors to Calculate Land Surface Temperature using MODIS Images

Land surface temperature (LST) is one of the most important parameters influencing physical processes of energy on the land surface and in high seas, both in local and global scales. Satellite infrared temperature data (TIR) is linked directly to LST using radiation transmission models. However, direct estimation of LST from radiation in TIR spectrum will be of low accuracy. Since the radiation measured by satellites depends not only on land surface parameters (temperature and irradiance power) but also on atmospheric influences. LST calculation suggests different methods for decreasing atmospheric influences, which can be classified in three major classes: single band methods, multiple band methods, and multiple angle methods. The present article investigates multi-temporal data of MODIS images in 12 different dates with quite uniform temporal distribution during 2014 using five useful multiple band methods of calculating LST including, Price Model (1994), Becker and Li Model (1990), Platt and Prata Model (1991), Ulivieri et al. model (1994), Coll et al. model (1994). Then, coefficients of investigated models were calibrated using the least repetitive squares model. During the calibration, main coefficients of the models were used as the initial value and optimal coefficients were calculated using a series of data. Afterward, the accuracy of the modified models was evaluated using LST from MODIS and the Iranian weather stations data. Results illustrate the modified Price Model by an average of RMSE 0.41 Centigrade degree as the most accurate model. Moreover, the variance of RMSE is 0.08 for mentioned dates which confirm generalizability of the outcomes. The maximum and minimum of RMSE equals 0.26 and 0.50 respectively (February 19th and June 27th respectively) for modified Price model. Finally, the linear relation was investigated, between LST calculated using modified Price Model and data measured by Iranian weather stations. The linear regression factor of these two series of data was 0.9978 which indicates a significant linear relation between calculated LST data and reference temperatures of the Iranian weather stations