Polynomiality for Bin Packing with a Constant Number of Item Types

We consider the bin packing problem with d different item sizes s_i and item multiplicities a_i, where all numbers are given in binary encoding. This problem formulation is also known as the 1-dimensional cutting stock problem. In this work, we provide an algorithm which, for constant d, solves bin packing in polynomial time. This was an open problem for all d >= 3. In fact, for constant d our algorithm solves the following problem in polynomial time: given two d-dimensional polytopes P and Q, find the smallest number of integer points in P whose sum lies in Q. Our approach also applies to high multiplicity scheduling problems in which the number of copies of each job type is given in binary encoding and each type comes with certain parameters such as release dates, processing times and deadlines. We show that a variety of high multiplicity scheduling problems can be solved in polynomial time if the number of job types is constant

Unsatisfying Wars: Degrees of Risk and the \u3ci\u3eJus ex Bello\u3c/i\u3e

Self-defensive war uses violence to transfer risks from one’s own people to others. We argue that central questions in just war theory may fruitfully be analyzed as issues about the morality of risk transfer. That includes the jus ex bello question of when states are required to accept a ceasefire in an otherwise-just war. In particular, a “war on terror” that ups the risks to outsiders cannot continue until the risk of terrorism has been reduced to zero or near zero. Some degree of security risk is inevitable when coexisting with others in the international community, just as citizens within a state must accept some ineradicable degree of crime as a fact of community life. We define a conception of morally legitimate bearable risk by contrasting it with two alternatives, and argue that states must stop fighting when they have achieved that level. We call this requirement the Principle of Just Management of Military Risk. We also argue that states should avoid exaggerated emphasis on security risks over equivalent risks from other sources—the Principle of Minimum Consistency Toward Risks. This latter principle is not a moral requirement. Rather, it is a heuristic intended to correct against well-known fallacies of risk perception that may lead states to overemphasize security risks and wrongly export the costs of their security onto others. In conclusion, we suggest that states must invest in non-violent defensive means as a precondition for legitimately using force externally

The Online Laboratory: Conducting Experiments in a Real Labor Market

Online labor markets have great potential as platforms for conducting experiments, as they provide immediate access to a large and diverse subject pool and allow researchers to conduct randomized controlled trials. We argue that online experiments can be just as valid---both internally and externally---as laboratory and field experiments, while requiring far less money and time to design and to conduct. In this paper, we first describe the benefits of conducting experiments in online labor markets; we then use one such market to replicate three classic experiments and confirm their results. We confirm that subjects (1) reverse decisions in response to how a decision-problem is framed, (2) have pro-social preferences (value payoffs to others positively), and (3) respond to priming by altering their choices. We also conduct a labor supply field experiment in which we confirm that workers have upward sloping labor supply curves. In addition to reporting these results, we discuss the unique threats to validity in an online setting and propose methods for coping with these threats. We also discuss the external validity of results from online domains and explain why online results can have external validity equal to or even better than that of traditional methods, depending on the research question. We conclude with our views on the potential role that online experiments can play within the social sciences, and then recommend software development priorities and best practices

Accountability, Incentives and Behavior: The Impact of High-Stakes Testing in the Chicago Public Schools

The recent federal education bill, No Child Left Behind, requires states to test students in grades three to eight each year, and to judge school performance on the basis of these test scores. While intended to maximize student learning, there is little empirical evidence about the effectiveness of such policies. This study examines the impact of an accountability policy implemented in the Chicago Public Schools in 1996-97. Using a panel of student-level, administrative data, I find that math and reading achievement increased sharply following the introduction of the accountability policy, in comparison to both prior achievement trends in the district and to changes experienced by other large, urban districts in the mid-west. I demonstrate that these gains were driven largely by increases in test-specific skills and student effort, and did not lead to comparable gains on a state-administered, low-stakes exam. I also find that teachers responded strategically to the incentives along a variety of dimensions -- by increasing special education placements, preemptively retaining students and substituting away from low-stakes subjects like science and social studies.

The BG News January 19, 2017

The BGSU campus student newspaper. January 19, 2017. Volume 96-Issue 36.https://scholarworks.bgsu.edu/bg-news/9955/thumbnail.jp

Center for Professional Ethics, Volume 4, Issue 2, 2003

Table of Contents: Waiting for the Courage to Die : The Role of Live Theatre in Medical Education by Fran Heller Building Bridges with Jonathan Sadowksy: A Reprint from the CWRU Observer Using Children in Research, Dr. Eric Kodish Explores and Explains A Glance at Professor Philip C. Bobbit: The Ends and Means of Stimulating Discussion Industry-Sponsored Research -- What\u27s Wrong? Professor Andrew Trew Talks About IRBs, Ethics and Patients Director\u27s Corner: The Aftermath of War by Robert P. Lawry Spring, 2003 News, Notes, and Future Eventshttps://scholarlycommons.law.case.edu/professional_ethics/1039/thumbnail.jp