We explore the effect of dimensionality on the nearest neighbor problem. We show that under a broad set of conditions (much broader than independent and identically distributed dimensions), as dimensionality increases, the distance to the nearest data point approaches the distance to the farthest data point. To provide a practical perspective, we present empirical results on both real and synthetic data sets that demonstrate that this effect can occur for as few as 10-15 dimensions. These results should not be interpreted to mean that high-dimensional indexing is never meaningful; we illustrate this point by identifying some high-dimensional workloads for which this effect does not occur. However, our results do emphasize that the methodology used almost universally in the database literature to evaluate high-dimensional indexing techniques is flawed, and should be modified. In particular, most such techniques proposed in the literature are not evaluated versus simple linear scan, and are evaluated over workloads for which nearest neighbor is not meaningful. Often, even the reported experiments, when analyzed carefully, show that linear scan would outperform the techniques being proposed on the workloads studied in high (10-15) dimensionality!.

When is nearest neighbor meaningful

Sociological studies sensitive to the issue of place are rarely labeled thus, and at the same time there are far too many of them to fit in this review. It may be a good thing that this research is seldom gathered up as a “sociology of place,” for that could ghettoize the subject as something of interest only to geographers, architects, or environmental historians. The point of this review is to indicate that sociologists have a stake in place no matter what they analyze, or how: The works cited below emplace inequality, difference, power, politics, interaction, community, social movements, deviance, crime, life course, science, identity, memory, history. After a prologue of definitions and methodological ruminations, I ask: How do places come to be the way they are, and how do places matter for social practices and historical change?

A Space for Place in Sociology

/pdf/preventing-crime-what-works-what-doesn-t-what-s-promising-1jp2dkc4ik.pdf

Preventing Crime: What Works, What Doesn't, What's Promising. Research in Brief. National Institute of Justice.

No wonder you activities are, reading will be always needed. It is not only to fulfil the duties that you need to finish in deadline time. Reading will encourage your mind and thoughts. Of course, reading will greatly develop your experiences about everything. Reading invisible colleges diffusion of knowledge in scientific communities is also a way as one of the collective books that gives many advantages. The advantages are not only for you, but for the other peoples with those meaningful benefits.

Invisible colleges : diffusion of knowledge in scientific communities

The literature on fear of crime has grown rapidly in the last three decades. This paper examines the reasons for this growth and attempts to put some structure on the work to date. The inadequacies of measures of fear of crime are discussed and alternative approaches suggested. Alternative explanatory theories are compared and strategies for reducing fear reviewed.

Fear of crime: A review of the literature.

This paper describes the latest stage of an ongoing attempt to update and upgrade CPTED’s concepts and actions and link them more closely to developments in architecture, design and crime science. The concept of territoriality, for example, is central to the practice domain of CPTED. Yet territoriality is only vaguely defined within that domain, as are the other core concepts such as activity support and target hardening; and all of them confusingly intersect and overlap. The paper attempts a remedy by developing a suite of definitions in depth, relating the core concepts to various frameworks and discourses developed for crime prevention and design against crime, and more generally exploring ways in which CPTED could become richer and more subtle. It will also consider the ‘dark side’ of the environment, covering offenders’ countermoves to prevention and their own counter-exploitation of space, buildings and what they contain. The ultimate intention is to produce a more rigorous, yet deeper and better-integrated conception of CPTED useful for practice, research and theory alike. The paper should be considered as work in progress, indicating what might be possible and stimulating debate rather than offering a definitive resolution of the issue. Further steps are suggested and constructive contributions from readers are invited.

Deconstructing CPTED… and Reconstructing it for Practice, Knowledge Management and Research

Most evaluations of crime prevention are carried out with little regard for methodological probity. Of work that aspires to methodological adequacy, the standard designs are the before-after comparison group and the interrupted time series. The critical questions are whether a program has an effect (and if not, whether because of theory failure, implementation failure, or measurement failure), the extent of any effect achieved, and the means by which it was achieved. The reduction of crime is a measure of outcomes, but others are often used. Clarity is necessary in the use of noncrime measures. Too often, evaluators settle for the "consolation prizes" of reductions in fear and incivilities. Distinct evaluative requirements attach to different types of prevention. Improvements in standard methodology and innovation by nonstandard approaches are needed. The "scientific realist" tradition eschews conventional one-shot quasi experimentation in favor of repeated manipulations leading to the cataloging of possible mechanisms and consistency of outcome pattern with presumed mechanisms. Different actors (practitioners, evaluators, administrators) have different objectives and interests; evaluators must take account of those differences. Language: en

Evaluating Crime Prevention

In showing more interest in the crime event than the offender, situational crime prevention has tended to be at the margins of mainstream academic criminology. Yet offenders can only exploit potential crime opportunities if they have the resources to take advantage of them. To understand how crime patterns are generated, situational crime prevention must also consider offender resources and their distribution and social-technical change. Resources have been central to much traditional offendei-centred criminology but mainly for understanding what motivates offending. Consideration of crime-resource needs, availability, development, distribution and change provides a potential bridge between traditional offender-centred criminology and situational crime prevention.

Going equipped - Criminology, situational crime prevention and the resourceful offender

This paper, in the only long-standing academic series covering situational crime prevention, initiated exploration of the purpose, nature and management of crime prevention knowledge It arose from my longstanding experience in practical prevention and its evaluation; awareness of failure in government programmes promulgating ‘evidence-based practice’ and interest in research-led demonstration projects; and international interest in ‘good practice’ databases

Viewing knowledge as a means for improving performance, the paper addresses a paradox: over-exact replication of interventions means poor adaptation to new, and different, contexts The resolution requires treating replication like innovation: practitioners should copy a design-like 'process' rather than an 'end product', replicating 'generic preventive principles', not detailed 'intervention methods', cookbook fashion 

Social/technological change and adaptive offenders demands continual replenishment of knowledge through ‘evolutionary’ and anticipatory techniques to out-innovate offenders 5Is closely integrates with the iterative process which characterises practice-led design and linkages are now being developed to guide design practitioners

The work reported generated a practical knowledge management schema applied within both UK and European Crime Prevention Network (EUCPN), based on my process model, the 5Is (which explicitly realises the arguments of this paper), and my Conjunction of Criminal Opportunity framework 5Is arose from the Danish Crime Prevention Council’s invitation to develop internationally transferable means for crime prevention practitioners to describe good practice It was used for successive EUCPN conferences A version was adopted by Swedish National Crime Prevention Council for filtering/enhancing local applications for funding; 5Is appears on a Mexican public security website ‘Research Utilisation’ researchers used my typology of knowledge The international Beccaria project for crime prevention quality incorporated the 5I’s concepts I have presented 5Is at the European Police College, it is used in teaching Masters students at UCL, and by the Japanese Urban Security Research Institute A book (Palgrave Macmillan) on 5I’s is in development

From the Source to the Mainstream is Uphill: The Challenge of Transferring Knowledge of Crime Prevention Through Replication, Innovation and Anticipation

Crime, unlike mercy, doesn’t fall like a gentle rain evenly covering the land – it gathers in pools. Risk of crime is concentrated in particular places (Eck et al., 2007), on particular victims (Farrell and Pease, 2008) and on particular products, the focus of this chapter. This concentration has two kinds of implication. On the one hand it gives strong clues about the causation of criminal events, whether concerning the targets or tools of those crimes or the insecurity of their immediate situation; on the other, it guides the kind of situational crime prevention (SCP) strategy that can be adopted. That strategy can be developed either in reaction to an established pattern of risk, or in anticipation, but in either case the underlying rationale is the same. If you – as policy-maker, police officer, designer, manufacturer or consumer – can identify the targets and tools at elevated risk of featuring in crime, then you can respectively concentrate your preventive policies and practices, direct your costly operational resources, design and incorporate elevated security performance in particular products, and choose the make and model of product you buy according to security ratings, as happens, say, with the UK car theft index (Laycock, 2004). 

There is much practice and research into how the design of the built environment increases, or decreases, the risk of crime. But this chapter covers products, essentially two- or three-dimensional objects that have been designed and manufactured in some way, and which may be portable (e.g. laptops), mobile (e.g. cars), movable (e.g. home cinema TV sets), incorporated (e.g. a tamper-evident lid for a medicine container) or installed (e.g. a cash machine). 

Classes of items at elevated risk of crime have been dubbed ‘hot products’ (Clarke, 1999), revisited below. Products may be hot by virtue of their intrinsic material value (such as jewellery or bronze statuary), their manufactured-in value (such as a mobile phone) or some combination. In either case, this ‘reward’ value (using rational choice perspective terms – Cornish and Clarke, 1986) is often accompanied by some kind of opportunity, enabling the product to be taken with relatively little effort or risk to the offender. Of course, risk and effort may partly reside in the nature of the environment in which the products are typically found, such as whether guardians of targets (Cohen and Felson, 1979) or other kinds of crime preventer (Ekblom, 2011) are present, capable and motivated. But much of that opportunity may reside in the rewarding and/or vulnerable design of the product itself; and even if the design is not obviously ‘culpable’ (e.g. an easy-to-steal car or a provocative poster) design solutions may be the most reliable and/or cost-effective remedy.

The first section of this chapter begins by defining key terms such as risk and risk factors. It then reviews how the latter feature in situational crime prevention notably via the phenomenon of hot products; the underlying causes of elevated risk; the risk life-cycle of products. The second part covers the response to elevated risk, notably via intervention through design, covering both content and process; anticipation of future risks; and evidence of effectiveness. As said, the focus is on two-and three-dimensional manufactured products excluding buildings and landscapes although some such products can be considered enclosures (such as handbags or vehicles) with ‘access control’ resemblances to buildings (you can break into a building or car, or slip or slash open a handbag or purse, to reach the contents you wish to steal). (The architectural approach known as Crime Prevention Through Environmental Design (CPTED – e.g. Armitage, [ref to chapter in this volume]) has developed its own terminological traditions – not always clear ones – and concepts and theory need integrating with SCP.) The important role of businesses in creating or reducing crime opportunities in manufactured products, and the difficulties of influencing their ‘design decision-making’ to give some weight to security, is covered only briefly; more is in Ekblom (2012a) and Hardie and Hobbs (2005). The creativity of criminals themselves is well-addressed in Cropley et al. (2010). The role of government in incentivising and otherwise leading on design is discussed in Clarke and Newman (2005) and was exemplified in the UK Home Office’s Design and Technology Alliance (see www.designcouncil.org.uk/our-work/challenges/security/design-out-crime/ for useful case studies).

/pdf/designing-products-against-crime-4astzsni8m.pdf

Paul Ekblom

Papers

Deconstructing CPTED… and Reconstructing it for Practice, Knowledge Management and Research

Evaluating Crime Prevention

Going equipped - Criminology, situational crime prevention and the resourceful offender

From the Source to the Mainstream is Uphill: The Challenge of Transferring Knowledge of Crime Prevention Through Replication, Innovation and Anticipation

Designing Products Against Crime