Open Lecture : Urban Development in a Global Era

This discussion is focused on urban development in advanced industrial nations over the past thirty years. Ten cities are selected and these include New York, Detroit, Houston, Toronto, Liverpool, Glasgow, Paris, Marseilles, Milan and Naples. The cities were chosen because they represent prosperous and distressed cities within each of five nations (United States, Canada, United Kingdom, France and Italy). The cities portray a wide range of urban policy responses and these resoponses are used to analyze successes and failures. Propositions are advanced that 1) cities have undergone very different changes and taken different development paths 2) globalization has profoundly affected cities and shaped their development strategies 3) certain characteristics and strategies enable cities to better cope with global transformation. After reviewing these characteristics an observation is made that there is an inherent tension between effective development strategies and socially redistributive policies. The discussion is concluded with recommendations for the most effective development strategies in an era of globalization. The recommendations are intended to apply to Tokyo as well as other advanced cities

Distinguishing sequences for partially specified FSMs

Distinguishing Sequences (DSs) are used inmany Finite State Machine (FSM) based test techniques. Although Partially Specified FSMs (PSFSMs) generalise FSMs, the computational complexity of constructing Adaptive and Preset DSs (ADSs/PDSs) for PSFSMs has not been addressed. This paper shows that it is possible to check the existence of an ADS in polynomial time but the corresponding problem for PDSs is PSPACE-complete. We also report on the results of experiments with benchmarks and over 8 * 106 PSFSMs. © 2014 Springer International Publishing

The Computational Complexity of Knot and Link Problems

We consider the problem of deciding whether a polygonal knot in 3-dimensional Euclidean space is unknotted, capable of being continuously deformed without self-intersection so that it lies in a plane. We show that this problem, {\sc unknotting problem} is in {\bf NP}. We also consider the problem, {\sc unknotting problem} of determining whether two or more such polygons can be split, or continuously deformed without self-intersection so that they occupy both sides of a plane without intersecting it. We show that it also is in NP. Finally, we show that the problem of determining the genus of a polygonal knot (a generalization of the problem of determining whether it is unknotted) is in {\bf PSPACE}. We also give exponential worst-case running time bounds for deterministic algorithms to solve each of these problems. These algorithms are based on the use of normal surfaces and decision procedures due to W. Haken, with recent extensions by W. Jaco and J. L. Tollefson.Comment: 32 pages, 1 figur

САМОПОГЛОЩЕНИЕ ИЗЛУЧЕНИЯ НА ДЛИНЕ ВОЛНЫ 213 нм ПРИ ЛАЗЕРНОМ ВОЗДЕЙСТВИИ НА РОГОВИЦУ ГЛАЗА

The laser ablation efficiency of cornea at 213 nm radiation was investigated and optimized. It is shown that self-absorption of radiation at 213 nm in a thin cloud of ablated material takes place and strongly influences the ablation efficiency. Ablation products are being blown out in the lateral direction along the cornea surface, as a result of which the pulse fluence at the pit boundary Fbnd is more than the threshold fluence Fth. As a consequence, a pit radius rbnd is less than a laser beam radius rth corresponding to the threshold fluence Fth that should be taken into account in planning ablation surgery at 213 nm radiation. Исследована и оптимизирована эффективность лазерной абляции роговицы глаза УФ-излучением с длиной волны 213 нм. Показано, что самопоглощение лазерного излучения 213 нм в тонком облаке испаренного материала сильно влияет на эффективность абляции. Продукты абляции выбрасываются в боковом направлении вдоль поверхности роговицы, в результате чего плотность энергии импульса на границе абляционной лунки Fbnd выше, чем пороговая плотность энергии Fth. Как следствие, радиус лунки rbnd меньше радиуса rth  лазерного луча, соответствующего пороговой плотности энергии импульса Fth, что необходимо учитывать при планировании абляционной хирургии глаза излучением 213 нм.

Spatial Dynamics Of Vertical And Horizontal Intergovernmental Collaboration

Although researchers have made progress in understanding motivations behind local government collaboration, there is little research that explores the spatial dynamics of such interactions. Does the idea of collaboration travel horizontally, passed from neighbor to neighbor, or is vertical leadership from state, county, or regional actors more important in influencing local governments’ decisions to share resources and functions? What factors influence local governments’ choices to collaborate with their neighbors versus a regional entity, county, or state government? In this article, we investigate the importance of vertical and horizontal influences when local governments decide to collaborate around land use planning. Using data from a survey of Michigan local government officials, we take a spatial statistical approach to answering this question. We find widespread evidence of collaboration at multiple scales, and observe patterns of both horizontal and vertical influence. We also find that contextual factors help to explain these patterns of collaboration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112248/1/juaf12139.pd

ЛАЗЕРНАЯ АБЛЯЦИОННАЯ ОБРАБОТКА РОГОВИЦЫ ГЛАЗА КОМБИНИРОВАННЫМ ИЗЛУЧЕНИЕМ 213+1440 нм

The laser ablation efficiency of eye cornea for UV (213 nm) and combined IR+UV (213 nm + 1444 nm) ablation treatment in safe conditions, preventing laser coagulation at 1444 nm, was investigated. It is shown that the IR+UV combination, when, at the first stage of cornea treatment, an IR laser pulse at 1444 nm, falling into a water absorption band with an absorption coefficient of about 31 cm–1, dehydrates a superficial corneal layer and at the second stage, in about 100 ms, a UV laser pulse at 213 nm ablates a thin (about 1–3 mm) collagen layer, gives promising results. Due to the controlled dehydration of the corneal surface, the process of 213 nm + 1444 nm laser ablation ensures a better reproducibility and a higher productivity. Исследована эффективность лазерной абляции роговицы глаза УФ-излучением (213 нм) и комбинированным УФ+ИК-излучением (213 нм + 1444 нм) в условиях обработки, когда лазерная коагуляция на длине волны 1444 нм не происходит. Показано, что комбинированное УФ+ИК-воздействие, когда сначала ИК-лазерный импульс (1440 нм), попадающий в полосу поглощения воды с коэффициентом поглощения около 31 см–1, обезвоживает поверхностный слой роговицы и следующий через ~100 мкс УФ-лазерный импульс (213 нм) удаляет тонкий поверхностный слой (1–3 мкм) коллагена, дает многообещающие результаты. Благодаря контролируемому обезвоживанию поверхности роговицы процесс лазерной абляции комбинированным (213 нм + 1444 нм) излучением обеспечивает лучшую воспроизводимость и более высокую производительность.

ОЦЕНКА ЭФФЕКТИВНОГО КОЭФФИЦИЕНТА ПОГЛОЩЕНИЯ РОГОВИЦЫ ГЛАЗА НА ДЛИНЕ ВОЛНЫ 213 НМ ИЗ АБЛЯЦИОННЫХ ИЗМЕРЕНИЙ

It is shown experimentally that a cornea represents a 213 nm UV inhomogeneous material both at depth and around a surface in relation to UV effective absorption coefficient and local laser depth ablation rate, which should be taken into account for a more exact planning of a profile of removed cornea collagen material during eye vision correction. Экспериментально показано, что роговица глаза для УФ-излучения (213 нм) представляет собой неоднородный материал как по глубине, так и вдоль поверхности, в отношении эффективного коэффициента поглощения и локальной скорости абляционного удаления материала роговицы, что необходимо учитывать для более точного планирования профиля удаляемого коллагена роговицы при операциях коррекции зрения.

PSPACE-completeness of Modular Supervisory Control Problems*

In this paper we investigate computational issues associated with the supervision of concurrent processes modeled as modular discrete-event systems. Here, modular discrete-event systems are sets of deterministic finite-state automata whose interaction is modeled by the parallel composition operation. Even with such a simple model process model, we show that in general many problems related to the supervision of these systems are PSPACE-complete. This shows that although there may be space-efficient methods for avoiding the state-explosion problem inherent to concurrent processes, there are most likely no time-efficient solutions that would aid in the study of such “large-scale” systems. We show our results using a reduction from a special class of automata intersection problem introduced here where behavior is assumed to be prefix-closed. We find that deciding if there exists a supervisor for a modular system to achieve a global specification is PSPACE-complete. We also show many verification problems for system supervision are PSPACE-complete, even for prefix-closed cases. Supervisor admissibility and online supervision operations are also discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45090/1/10626_2004_Article_6210.pd