Decomposability and scalability in space-based observatory scheduling

In this paper, we discuss issues of problem and model decomposition within the HSTS scheduling framework. HSTS was developed and originally applied in the context of the Hubble Space Telescope (HST) scheduling problem, motivated by the limitations of the current solution and, more generally, the insufficiency of classical planning and scheduling approaches in this problem context. We first summarize the salient architectural characteristics of HSTS and their relationship to previous scheduling and AI planning research. Then, we describe some key problem decomposition techniques supported by HSTS and underlying our integrated planning and scheduling approach, and we discuss the leverage they provide in solving space-based observatory scheduling problems

State-based scheduling: An architecture for telescope observation scheduling

The applicability of constraint-based scheduling, a methodology previously developed and validated in the domain of factory scheduling, is extended to problem domains that require attendance to a wider range of state-dependent constraints. The problem of constructing and maintaining a short-term observation schedule for the Hubble Space Telescope (HST), which typifies this type of domain is the focus of interest. The nature of the constraints encountered in the HST domain is examined, system requirements are discussed with respect to utilization of a constraint-based scheduling methodology in such domains, and a general framework for state-based scheduling is presented

Balancing antagonistic time and resource utilization constraints in over-subscribed scheduling problems

In this paper, we report work aimed at applying concepts of constraint-based problem structuring and multi-perspective scheduling to an over-subscribed scheduling problem. Previous research has demonstrated the utility of these concepts as a means for effectively balancing conflicting objectives in constraint-relaxable scheduling problems, and our goal here is to provide evidence of their similar potential in the context of HST observation scheduling. To this end, we define and experimentally assess the performance of two time-bounded heuristic scheduling strategies in balancing the tradeoff between resource setup time minimization and satisfaction of absolute time constraints. The first strategy considered is motivated by dispatch-based manufacturing scheduling research, and employs a problem decomposition that concentrates local search on minimizing resource idle time due to setup activities. The second is motivated by research in opportunistic scheduling and advocates a problem decomposition that focuses attention on the goal activities that have the tightest temporal constraints. Analysis of experimental results gives evidence of differential superiority on the part of each strategy in different problem solving circumstances. A composite strategy based on recognition of characteristics of the current problem solving state is then defined and tested to illustrate the potential benefits of constraint-based problem structuring and multi-perspective scheduling in over-subscribe scheduling problems

Federalization\u27s Folly

Overcriminalization and overpunishment are the two key features of federal criminal law today, yet the constant drumbeat to “federalize” criminal law has accomplished precious little in terms of public safety. The failed drug war proves as much: federal prosecutors have filled the nation’s prisons with low-level drug dealers and drug users serving long sentences, but drugs remain widely available at greater purity and lower prices throughout the land — and drug overdoses are at record highs. Instead of focusing on areas of federal comparative advantage, such as terrorism, international drug trafficking, and organized crime, federal prosecutors waste scarce resources “playing district attorney” — that is to say, pursing many of the same kinds of street crimes that state prosecutors do. The result is a federal prison population that is bursting at the seams, and a national drug problem that has never been worse.The time has come for a major overhaul of federal criminal law

Proportional Mens Rea

This Essay makes the case for proportional mens rea, a proportionality-based approach to mens rea selection. Proportional mens rea would provide proportionality safeguards that are otherwise entirely lacking in substantive criminal law and,as a practical matter, unavailable in constitutional law. Creating implied mens rea requirements, where necessary to ensure proportional punishment, is not a judicial usurpation of a legislative function. Rather, it is to take seriously the role that courts play, under both constitutional and substantive criminal law, to ensure that punishment fits the crime. Moreover, proportional mens rea would represent a needed counterweight to prosecutorial behavior whereas current doctrine does not. Given that federal prosecutors do not seek to charge morally blameless people, mens rea doctrine aimed only at protecting moral blamelessness from punishment will largely be redundant of prosecutorial discretion. Proportionality of punishment, however, is a concern that federal prosecutors—bound by long standing Executive Branch mandates to seek the maximum supportable penalty in every case and oppose lenient exercises of judicial sentencing discretion—routinely ignore. Judicial mens rea selection, therefore, has a substantial contribution to make to the achievement of proportionality of punishment

The Rehnquist Court and Criminal Procedure

Much of recent discussions of conservative judicial activism has concerned the revival of federalism-based limits on Congress during the Rehnquist Court. The allure of federalism as a topic for discussion is understandable, yet I argue that constitutional criminal procedure provides a better context within which to test the Rehnquist Court\u27s commitment to judicial restraint. In this Essay, I examine the topic at hand against the background of the many important developments that have taken place in criminal procedure on Rehnquist\u27s watch. The results of this examination are surprising because they suggest that activism is not necessarily the antithesis of restraint. That is to say, although the Court has indeed been activist in criminal procedure, its activism may ultimately serve the goal of judicial restraint. If in fact it does, then believers in judicial restraint should embrace rather than condemn the Court\u27s activism

Jail for Juvenile Child Pornographers?: A Reply to Professor Leary

Even though Professor Leary and I are united in the goal of protecting children against sexual exploitation, we part company on the proper societal response to the problem of self-produced child pornography. In my view, children who produce and distribute pornographic images of themselves ordinarily should not be regarded as proper objects of punishment. In this context, child protective services, backed up if necessary by the threat of criminal prosecution, is a much more appropriate way of reforming minors and protecting them against the serious dangers to which they expose themselves by creating and distributing pornographic images of themselves. A prosecution-based response, though essential for sexual predators and others involved in the sexual exploitation of minors, would create far more problems than it would solve for minors who make the mistake of creating and distributing pornographic images of themselves