Agricultural cooperatives have the main goals of meeting economic, social and cultural needs their members. Although they do not seek profits, must be competitive since compete with other companies in market. In this sense, search for technical efficiency to give a better market position contrasts difficulty these organizations face obtaining foreign capital enable greater investments. There is...

Complete row and column symmetry breaking in constraint models using the lex leader method is generally prohibitively costly. Double lex, which is derived from lex leader, is commonly used in practice as an incomplete symmetrybreaking method for row and column symmetries. Double lex is based on a rowwise canonical variable ordering. However, this choice is arbitrary. We investigate other canoni...

Expectations surrounding the role of e-learning need to be tempered by an awareness of the variety of technical, institutional, social and economic constraints on the innovation process. This paper reports on a case study of the introduction into a university of one of the most central e-learning initiatives in higher education, an enterprise-wide virtual learning environment. Findings identify...

Vegetable production constitutes an important sub-sector of the agricultural economy of KwaZulu-Natal. Most vegetables are cultivated in mixed-cropping types of farming systems. The technical efficiency of vegetable based cropping systems was estimated in order to identify the potential increase in production without incurring additional costs. The factors affecting technical efficiency and con...

Abstract The leather value chain starts with livestock, the key source of hides and skins, main raw materials for industry. Despite having second-largest livestock population in Africa, Tanzania is only 11th largest exporter on continent, underlining disproportionate contribution sector to economy. This study presents results a recent assessment aimed at identifying performance bottlenecks Tanz...

Linear equality and inequality constraints arise naturally in specifying many aspects of user interfaces, such as requiring that one window be to the left of another, requiring that a pane occupy the leftmost 1/3 of a window, or preferring that an object be contained within a rectangle if possible. Current constraint solvers designed for UI applications cannot efficiently handle simultaneous li...