Balancing contractual and relational approaches for PPP success and sustainability

Useful synergies are targeted by proposing a convergence of hitherto parallel international endeavours towards: (1) developing better and sustainable relationships for more productive construction project teams, in general; and (2) optimising the necessarily long term contractual arrangements of PPPs in particular. Examples are drawn from Africa and Latin America to reinforce reported PPP experiences from other regions, in building up a case for injecting ‘relational contracting approaches’ in order to develop more productive and sustainable PPPs. Strong and sustainable relationships are shown to be essential, and complementary to appropriate contractual incentives, that would together empower PPP project teams to focus on developing sustainable infrastructure and ultimately on overall sustainable development. These propositions are merged into a basic model that merits further investigation and development, in order to ensure that planned PPPs benefit the community at large, in respect of both present and future generations

Solution of Linear Programming Problems using a Neural Network with Non-Linear Feedback

This paper presents a recurrent neural circuit for solving linear programming problems. The objective is to minimize a linear cost function subject to linear constraints. The proposed circuit employs non-linear feedback, in the form of unipolar comparators, to introduce transcendental terms in the energy function ensuring fast convergence to the solution. The proof of validity of the energy function is also provided. The hardware complexity of the proposed circuit compares favorably with other proposed circuits for the same task. PSPICE simulation results are presented for a chosen optimization problem and are found to agree with the algebraic solution. Hardware test results for a 2–variable problem further serve to strengthen the proposed theory

Helicity-1/2 Mode as a Probe of Interactions of Massive Rarita-Schwinger Field

We consider the electromagnetic and gravitational interactions of a massive Rarita-Schwinger field. Stueckelberg analysis of the system, when coupled to electromagnetism in flat space or to gravity, reveals in either case that the effective field theory has a model-independent upper bound on its UV cutoff, which is finite but parametrically larger than the particle's mass. It is the helicity-1/2 mode that becomes strongly coupled at the cutoff scale. If the interactions are inconsistent, the same mode becomes a telltale sign of pathologies. Alternatively, consistent interactions are those that propagate this mode within the light cone. Studying its dynamics not only sheds light on the Velo-Zwanziger acausality, but also elucidates why supergravity and other known consistent models are pathology-free.Comment: 18 pages, cutoff analysis improved, to appear in PR

The effect of time manipulation on immersion in digital games

Many empirical studies look into identifying factors that influence the quality of experience in video games. In this paper, we present research into the effect of playing time and players’ perception of the time on their immersion in the game. We invited 20 participants to play a puzzle game Bejeweled 2 for 7 min. They played the game in two conditions, namely, correct time (timer was programmed to be exactly 7 min) and wrong time (the countdown was set to be for 6 min, but was presented as a 7 min timer to the player). Players’ immersion scores were measured after the game using the IEQ. The results show no significant difference in immersion scores between the two conditions and participants’ comments also revealed that they perceived no difference in playing time between the conditions. This suggests that there is a dissociation between gaming time and subjective experience of gaming. Further research is required to investigate the relationship between playing time and positive gaming experiences