In this paper, we study the integrality gap of the Knapsack linear program in the SheraliAdams and Lasserre hierarchies. First, we show that an integrality gap of 2 − ǫ persists up to a linear number of rounds of Sherali-Adams, despite the fact that Knapsack admits a fully polynomial time approximation scheme [27, 33]. Second, we show that the Lasserre hierarchy closes the gap quickly. Specific...

Approximating the optimal social welfare while preserving truthfulness is a well studied problem in algorithmic mechanism design. Assuming that the social welfare of a given mechanism design problem can be optimized by an integer program whose integrality gap is at most α, Lavi and Swamy [1] propose a general approach to designing a randomized α-approximation mechanism which is truthful in expe...

Suppose that we are given a feasible conic program with a finite optimal value and with strong duality failing. It is known that there are small perturbations of the problem data that lead to relatively big changes in the optimal value. We quantify the notion of big change in the case of a semidefinite program (SDP). We first show that for any SDP with a finite optimal value where strong dualit...

Safety is a critical issue for the construction industry. Literature argues that human error contributes to more than half of occupational incidents and could be directly impacted by effective training programs. This paper reviews the current safety training status in the US construction industry. Results from the review evidence the gap between the status and industry expectation on safety. To...

conclusions a significant association was found between ages of women with their delays in consultation. delay is still prevalent amongst women with breast cancer. it seems necessary to design educating programs for women in both clinical and community settings, about breast cancer and early detection practices. results the mean age of women was 46.99 years. 38.4% of women were ≤ 40 years. 61% ...

There is a gap between refactoring tools and generalpurpose program transformation tools that has yet to be filled. Refactoring tools are easy to use and wellestablished, but provide only a limited number of options. On the other hand, program transformation tools are powerful but are viable only for large transformation tasks. We propose an approach in which a developer specifies transformatio...

This paper outlines a new program called E-TRAN, which bridges the gap between loadflow/stability programs and electro-magnetic transients programs. It is essentially a translation program for power systems, but includes many features to avoid manual calculations (such as the automated formation of multi-port network equivalents, initialization of machines/sources in large systems, auto-routing...

We consider constrained discounted-cost Markov control processes in Bore1 spaces, with unbounded costs. Conditions are given for the constrained problem to be solvable, and also equivalent to an equality-constrained (EC) 1' inear program. In addition, it is shown that there is no duality gap between EC and its dual program EC*, and that, under additional assumptions, also EC* is solvable, so th...