Lifting, tilting and fractional programming, though seemingly different, reduce to a common optimization problem. This connection allows us to revisit key properties of these three problems on mixed integer linear sets. We introduce a simple common framework for these problems, and extend known results from each to the other two.

We consider the logical theory of the monoid of subsets of N endowed solely with addition lifted to sets: no other set theoretical predicate or function, no constant (contrarily to previous work by Jeż and Okhotin cited below). We prove that the class of true Σ5 formulas is undecidable and that the whole theory is recursively isomorphic to second-order arithmetic. Also, each ultimately periodic...

This study investigated the effects of initial load height and foot placement instruction in four lifting techniques: free, stoop (bending the back), squat (bending the knees) and a modified squat technique (bending the knees and rotating them outward). A 2D dynamic linked segment model was combined with an EMG assisted trunk muscle model to quantify kinematics and low back loading in 10 subjec...

OBJECTIVES To assess the criterion-related validity of the five Ergo-Kit (EK) functional capacity evaluation (FCE) lifting tests in construction workers on sick leave due to musculoskeletal disorders (MSDs). METHODS Six weeks, 6 months and 1 year after the first sick leave day due to MSDs, construction workers underwent two isometric and three dynamic EK FCE lifting tests, and completed the I...

This study recruited 14 young male participants to examine human 4-h maximum acceptable weight of lifting (MAWL) and maximum weight of lifting (MWL) for different modes of asymmetric lifting and containers. The results showed that asymmetric lifting with trunk rotation decreased MAWL and MWL by 9.1 and 17.3%, respectively, and asymmetric lifting with body turn decreased MAWL and MWL by 6.1%, wh...

A semantic formulation of Lindley and Stark’s >>-lifting is given. We first illustrate our semantic formulation of the >>-lifting in Set with several examples, and apply it to the logical predicates for Moggi’s computational metalanguage. We then abstract the semantic >>-lifting as the lifting of strong monads across bifibrations with lifted symmetric monoidal closed structures.

Occupational low back pain (LBP) is an immense burden for both industry and medicine. Ergonomic and personal risk factors result in LBP, but psychosocial factors can influence LBP disability. Epidemiologic studies clearly indicate the role of mechanical loads on the etiology of occupational LBP. Occupational exposures such as lifting, particularly in awkward postures; heavy lifting; or repetiti...

We consider the problem of separating maximally violated inequalities for the precedence constrained knapsack problem. Though we consider maximally violated constraints in general, special emphasis is placed on induced cover inequalities and induced clique inequalities. Our contributions include a new partial characterization of maximally violated inequalities, a new safe shrinking technique, a...