Location Of Units Research Articles

The Students for Peace Project: A Comprehensive Violence-Prevention Program for Middle School Students

Students for Peace is a three-year project (October 1993- September 1996) designed to evaluate a comprehensive, school-based intervention that seeks to prevent violence among sixth-, seventh-, and eighth-grade students in a large urban school district in Texas. This study examines the hypothesis that students exposed to a two-year multiple-component intervention will reduce aggressive behavior compared to students who receive the district's "usual care" of violence prevention activities. Students for Peace is based largely on Social Learning. Theory (SLT), which addresses both the psychosocial dynamics underlying health behavior and the methods of promoting behavior change, while emphasizing cognitive processes and their effect on behavior. SLT explains human behavior in terms of a model in which three factors-behavior, social-environmental influences, and personal factors (such as personality, perceptions and expectations, and affect)-all interact. Theoretically, an individual's behavior is uniquely determined by a combination of these factors; thus, these factors become the elements for intervention strategies. The intervention program includes four main components: (1) modification of the school environment, (2) a violence-prevention curriculum, (3) peer leadership, and (4) parent education. Students for Peace is using a nested cross-sectional and cohort design in which school is the unit of design, allocation, and analysis. Eight schools, four intervention and four control, are participating. In May 1994, a questionnaire was administered to all students in school the day of the survey. A posttest evaluation was taken in the spring of 1995 and will be followed by a final posttest in spring 1996. A total of 8,865 students responded to the baseline survey. Nearly all variables indicated comparability between treatment and control conditions. As a population, Students for Peace participants are largely Hispanic (65%) or African American (19%). Violence-related variables indicated 30-day fighting prevalence, 23%; 12-month prevalence of injuries due to fighting, 14%; 30-day hand-gun carrying prevalence, 11%; 30-day prevalence of taunts and threats at school, 27%, and threats going to and from school, 26%. Overall, the data from Year 1 activities indicate a population in need of violence-prevention intervention. The challenge is to mold existing district resources into a theoretically sound program of interventions. If that program is found effective, the district will already have the necessary documentation, personnel, and skills for broader dissemination.

Has general practitioner computing made a difference to patient care? A systematic review of published reports

To review findings from studies of the influence of desktop computers on primary care consultations. Systematic review of world reports from 1984 to 1994. The computerised catalogues of Medline, BIDS, and GPlit were searched, as well as conference proceedings, books, bibliographies, and references in books and journal articles. 30 papers met the inclusion criteria and were included for detailed review. A validated scheme for assessing methodological adequacy was used to score each paper. Papers were rated on sample formation, baseline differences, unit of allocation, outcome measures, and follow up. Differences in outcomes were also recorded. Four of the six papers dealing with the consultation process showed that consultations took longer. Doctor initiated and "medical" content of consultations increased at the expense of a reduction in patient initiated and "social" content. Each of the 21 studies which looked at clinician performance showed an improvement when a computer was used (from 8% to 50%, with better results for single preventive measures). Only one of the three studies looking at patient outcomes showed an improvement (diastolic blood pressure control 5 mm Hg better after one year, with fewer doctor-patient consultations). Using a computer in the consultation may help improve clinician performance but may increase the length of the consultation. More studies are needed to assess the effects on patient outcomes of using a computer in consultations.

Multiversion object constellations: A new approach to support a designer's database work

The logical organization of database support for CAD applications is considered, which has to account for specific requirements including versioning, consistency and design transactions. A new approach to the organization, manipulation and management of design objects in a design database is described, which is based on the notion of an objectconstellation. A constellation is a set of multiversion objects together with all their subobjects. Constellations can be versioned intoconfigurations, which comprise one version of each object of the underlying constellation. We argue that constellations are adequate units of allocation to individual designers, while configurations form appropriate units of consistency. We show how the constellation approach renders a flexible support of hierarchically organized, cooperative design processes possible, by employing specific transactions whose scope is limited to well-defined portions of a database. Most importantly, the approach provides new insight into the consistency problem for design databases, by providing an adequate approach to multilevel consistency, and by making consistency of a design context-dependent.

Methods for Comparing Event Rates in Intervention Studies When the Unit of Allocation is a Cluster

The aim of many research investigations is to compare the proportion of individuals in each of several groups that have a certain characteristic. The unit of allocation for such investigations is often an intact social unit, as in randomizing families, medical practices, schools, or entire communities, to different intervention groups. Standard statistical methods are not appropriate for these designs, since they do not take into account the dependencies among individuals within the same cluster. The authors review the strengths and weaknesses of several approaches for dealing with this problem, using data from a school-based smoking cessation trial. A principal conclusion is that the choice of method should depend on whether or not random allocation is used in the assignment of interventions.

Networking and Information Distribution in Robots Composed of Identical Units.

Robotic systems composed of identical units can be made flexible in size, degrees of freedom, and output motions in response to desired tasks. There are three basic characteristics which are desirable in such systems : (1) expandability, (2) perceptibility of unit's location, and (3) fault tolerance. These characteristics can be varied depending on the networking and information distribution scheme adopted. The present paper proposes a method of classifying and comparing networking schemes for such robotic systems based on the above-mentioned basic characteristics, and the optimal networking scheme is then clarified for a particular application. An experimental transfer robot composed of identical units, each of which has nineteen arms, was constructed, and the experimental results are shown to support the proposed method.

The Doppler sensitivity of large TW phase modulated waveforms

The narrowband approach to coherent processing of large-TW waveforms in Doppler delay multiplies the data stream by the complex conjugate of the undilated envelope and uses FFT processing to test Doppler. This results in a correlation loss that depends fundamentally on the TW product of the waveform envelope and the amount of Doppler-induced time-base dilation occurring in the data. It is shown that it is possible to reduce the number of dilated envelope replicas required to cover a given Doppler band by dividing the band into subbands. Each narrowband is processed using an envelope replica with a fixed dilation parameter, and the width of each band is a function of a specified correlation loss limit, the TW product, and a Doppler sensitivity parameter that depends on the specific time-frequency allocation of the envelope. Examples are provided for envelopes with both continuous and discrete (FSK) allocations with emphasis on the class of unit allocation (UA) codes that includes all full Costas arrays, for which upper and lower bounds for Doppler sensitivity are derived.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On Networking and Knowledge Distribution in Robots Composed of Identical Units.

Robotic systems can be made flexible in their size, degrees of freedom, outputs for a desired task by composing them of identical units. There are three basic characteristics which are desirable in such systems; (1) expandability, (2) perceptibility of unit's location, and (3) fault tolerance. These characteristics of the system can be varied by the networking and knowledge distribution scheme employed. This paper proposes a method of classifying and comparing networking schemes for such robotic systems based on the above-mentioned three basic characteristics, and the optimal networking scheme is then made clear for a particular application. An experimental transfer robot composed of identical units, each of which has nineteen arms, was built and the experimental results are shown to support the proposed method.

Some properties of the sequential Markovian allocation problem

This paper deals with a stochastic allocation problem associated with the Markov chain. The object is to maximize the expected present value of the sum of the values of the random variables sampled from the process. The maximum number of the allocation units is fixed and the decision to accept or reject the current observation is based on the known and unknown transition probabilities. The problem is formulated and the optimal decision rule derived by the technique of dynamic programming. Certain computational aspects of the optimal decision rule with some numerical results are also presented, and finally, some promising real-life applications and extensions of the models are discussed.

An object oriented approach to virtual nodes: are package types an answer?

It is considered that a language supporting the construction of distributed systems must possess some structuring feature enabling the construction of components suitable to serve as units of network allocation and system reconfiguration. In some earlier studies of the distribution of Ada such units have been referred to as virtual nodes. [Hutcheon and Wellings 1988, Atkinson et al 1988].This paper discusses whether objects in the sense of object oriented systems are suitable to serve as virtual nodes (VNs). It then considers whether the introduction of package types could provide the kind of class object which is found in object oriented languages.In a system for the support of distribution there must also be support for network communications. The paper discusses briefly how network communication between objects can be provided.

BELGIAN HEART DISEASE PREVENTION PROJECT: INCIDENCE AND MORTALITY RESULTS

Results are presented from the Belgian Heart Disease Prevention Project, part of the WHO European Collaborative Trial in the Multifactorial Prevention of Coronary Heart Disease (CHD). 19 409 men aged 40-59 yr took part; they were employed in thirty factories which formed the allocation units for a randomised controlled trial lasting 5-6 yr. The intervention package consisted largely of health education promoting a cholesterol-lowering diet, smoking cessation, weight control, physical activity, and treatment of arterial hypertension. A programme of information was supplemented by face-to-face counselling at the workplace by two physicians attached to the project. The coronary risk profile was reduced in the intervention group, compared with that in the control group, especially during the first 4 yr, by effects on serum cholesterol, number of cigarettes smoked daily, and arterial blood-pressure. Total mortality was 17·5% lower in the intervention group than in the control group (p=0·038). Coronary mortality was reduced by a non-significant 20·8% whereas CHD incidence (non-fatal myocardial infarction plus fatal myocardial infarction plus sudden deaths) was reduced by 24·5% (p=0·031). Non-fatal myocardial infarction (not a major end-point) was similarly reduced by 26·1% (p=0·030).

UK HEART DISEASE PREVENTION PROJECT: INCIDENCE AND MORTALITY RESULTS

Results are presented for the UK centre of the WHO European Collaborative Trial in the Multifactorial Prevention of Coronary Heart Disease (CHD). 18 210 men took part, aged 40 to 59; they were employed in 24 factories, which formed the allocation units for a randomised controlled trial lasting 5-6 years. Intervention comprised advice on cholesterol-lowering diet, smoking cessation, weight control, exercise, and treatment of hypertension. Advice was given mainly through factory medical departments, the staff being supplemented a little by a visiting central team. Self-reported cigarette smoking was moderately reduced, but changes in other risk factors were small and not well sustained. There was no clear effect on hard CHD end-points (coronary deaths and myocardial infarction) or on all-causes mortality. However, there was a 36% reduction in the rate at which intervention subjects reported ill with other CHD (principally angina) during the study, and at the end fewer intervention men gave positive responses to a self-administered questionnaire on angina and chest pain. These apparent benefits were not substantiated by electrocardiographic evidence, suggesting that participation in a heart disease prevention campaign may bias reporting of symptoms. Experience in other centres of the Collaborative Trial, however, suggests that more effective risk factor control does reduce CHD incidence and mortality. This implies that for the UK the problem is to find means of enhancing the acceptance of health advice.

Single-unit activity in the auditory cortex of monkeys actively localizing sound sources: Spatial tuning and behavioral dependency

Single-unit recordings were made from the auditory cortex of unanesthetized rhesus monkeys which were trained to perform a sound localization task. Recordings were made from 196 units in 4 animals. Five sound sources were located at 0° (midline) and on either side at azimuths of 37.5° and 75°. Although most units responded to each of the 5 sources, 49% of the units had peak firing rates for the source on the contralateral side at 75° azimuth. Another 26% of the units had peak firing rates at the 37.5° contralateral location, while only 11% had peak rates for the ipsilateral locations. In order to determine whether the behavior of actively locating a sound source affected units in auditory cortex, response rates were compared under two behavioral conditions: one which required the detection of a sound regardless of location and another condition which required identification of a sound's location. Of the 196 units, 16 had different response rates for the two conditions, with 15 of the 16 units having higher evoked rates in the localization task. For the 16 units, the difference in firing rate was typically observed only for a single speaker location. No correlation could be determined between a unit's location within the subdivisions of auditory cortex and its spatial tuning response properties or its dependency upon behavioral condition.

INTERCOMMUNITY SPILLOVERS AND THE PROVISION OF PUBLIC EDUCATION

This paper develops a conceptual framework for the systematic analysis of inter-community spillovers and their implications for local expenditure-investment decisions. Spillovers are distinguished on the basis of the effects they have upon the rate of exchange between current goods for private consumption and publicly provided goods. The mechanisms of spillovers—economic interaction, fiscal inter-dependence, and migration—and the concept of community are examined in this context. A diagrammatic analysis is used to demonstrate the influence of spill-overs on the decision making unit's allocation of resources. Methodological issues and problems involved in estimating spillover magnitudes are presented. A case study provides numerical counterparts for the theoretical quantities of the analysis. While emphasis is on publicly provided education in the United States, the framework and methodology should be applicable to other local governments and their services.

Gewann System and Jori System

In areas where the Jori-system (a kind of township in old Japan) still exists, the term “Aza” is used to mark sections of the field. “Aza” usually corresponds with “Tsubo” which is the smallest unit of “Ri”.Each section of “Aza” is usually irregular Blockflur, but in the areas where the Jori-system still exists the strips are regular Streifenflur (about 13m×130m) and is similar to Kruzstreifenflur, according to G. Niemeier's classification of field patterns.The type of field corresponding to Langstreifenflur, Which is the oldest type of field found in Germany according to him, are not found in Japan.The strips of Jori have frequently been changed into Block-flur during the years with the redistribution of land.Gewann and Feld were regional units which controlled communal land ownership and agricultural operation (in Germany). As for “Aza” in Japan, in paddy fields requiring irrigation, strips in the same “Aza” were and still are frequently irrigated by the same irrigation canal. The smallest group of people engaged in rice-planting or irrigation is formed among farmers who have paddy-fields in the same “Aza” rather than among neighbors.If we look at a section in the old Chinese Seiden system, which is a prototype of the Japanese Jori-system, we see that this section is a square which eight families cultivated, and one unit with the same communal controls for irrigation and cultivation.The writer would take “Aza” and Gewann for the smallest unit of the regior, ecotop. However, in contrast to Gewann and Feld in the three field system of western Europe, “Aza” has played no regional function as a unit of property allocation.