Towards a change process planning tool

The relationship between a product and its design process is generally complex and not fully understood. When modifying a product, industry still rarely considers the implementation process and its consequences for other design activities in the company, which is hard to assess with conventional planning methods. Although change processes are highly constrained, product and process constraints are not usually considered together or traded off against each other when planning the change. Inadequate assessment and planning of the change implementation process can lead to costly knock-on effects across the product and the design process. This paper argues for a combination of change and process research and discusses requirements for a change process planning tool. It proposes a system for the analysis of the impact of change on the product as well as other company activities. Then, a more informed selection between change alternatives is possible

Relating the radar backscattering coefficient to leaf-area index

The relationship between the radar backscattering coefficient of a vegetation canopy, sigma(0) sub can, and the canopy's leaf area index (LAI) is examined. The relationship is established through the development of a model for corn and sorghum and another for wheat. Both models are extensions of the cloud model of Attema and Ulaby (1978). Analysis of experimental data measured at 8.6, 13.0, 17.0, and 35.6 GHz indicates that most of the temporal variations of sigma(0) sub can can be accounted for through variations in green LAI alone, if the latter is greater than 0.5

A functional analysis of change propagation

A thorough understanding of change propagation is fundamental to effective change management during product redesign. A new model of change propagation, as a result of the interaction of form and function is presented and used to develop an analysis method that determines how change is likely to propagate. The analysis produces a Design Structure Matrix, which clearly illustrates change propagation paths and highlights connections that could otherwise be ignored. This provides the user with an in-depth knowledge of product connectivity, which has the potential to support the design process and reduce the product's susceptibility to future change

The Policy of Enforcement: Red Light Cameras and Racial Profiling

The article of record as published may be located at http://dx.doi.org/10.1177/1098611115586174We explore the question of whether some of the often conflicting evidence of racial profiling can be cleared up using red light camera observations to measure racial disparities in traffic violations. Using data from cameras at intersections matched to census data, we find that although citations from the red light cameras are issued to a disproportionate number of minorities based on the racial composition of the surrounding location, the racial composition of the violator is consistent with the racial composition of the block group in which they reside. Our study indicates that red light cameras may have a present and future role in assisting public policy makers on issues of racial profiling thresholds

Inert gas clearance from tissue by co-currently and counter-currently arranged microvessels

To elucidate the clearance of dissolved inert gas from tissues, we have developed numerical models of gas transport in a cylindrical block of tissue supplied by one or two capillaries. With two capillaries, attention is given to the effects of co-current and counter-current flow on tissue gas clearance. Clearance by counter-current flow is compared with clearance by a single capillary or by two co-currently arranged capillaries. Effects of the blood velocity, solubility, and diffusivity of the gas in the tissue are investigated using parameters with physiological values. It is found that under the conditions investigated, almost identical clearances are achieved by a single capillary as by a co-current pair when the total flow per tissue volume in each unit is the same (i.e., flow velocity in the single capillary is twice that in each co-current vessel). For both co-current and counter-current arrangements, approximate linear relations exist between the tissue gas clearance rate and tissue blood perfusion rate. However, the counter-current arrangement of capillaries results in less-efficient clearance of the inert gas from tissues. Furthermore, this difference in efficiency increases at higher blood flow rates. At a given blood flow, the simple conduction-capacitance model, which has been used to estimate tissue blood perfusion rate from inert gas clearance, underestimates gas clearance rates predicted by the numerical models for single vessel or for two vessels with co-current flow. This difference is accounted for in discussion, which also considers the choice of parameters and possible effects of microvascular architecture on the interpretation of tissue inert gas clearance

Discovery of new TeV supernova remnant shells in the Galactic plane with H.E.S.S

Supernova remnants (SNRs) are prime candidates for efficient particle acceleration up to the knee in the cosmic ray particle spectrum. In this work we present a new method for a systematic search for new TeV-emitting SNR shells in 2864 hours of H.E.S.S. phase I data used for the H.E.S.S. Galactic Plane Survey. This new method, which correctly identifies the known shell morphologies of the TeV SNRs covered by the survey, HESS J1731-347, RX 1713.7-3946, RCW 86, and Vela Junior, reveals also the existence of three new SNR candidates. All three candidates were extensively studied regarding their morphological, spectral, and multi-wavelength (MWL) properties. HESS J1534-571 was associated with the radio SNR candidate G323.7-1.0, and thus is classified as an SNR. HESS J1912+101 and HESS J1614-518, on the other hand, do not have radio or X-ray counterparts that would permit to identify them firmly as SNRs, and therefore they remain SNR candidates, discovered first at TeV energies as such. Further MWL follow up observations are needed to confirm that these newly discovered SNR candidates are indeed SNRs

Chandra detection of diffuse X-ray emission from the globular cluster Terzan 5

Terzan 5, a globular cluster (GC) prominent in mass and population of compact objects, is searched for diffuse X-ray emission, as proposed by several models. We analyzed the data of an archival Chandra observation of Terzan 5 to search for extended diffuse X-ray emission outside the half-mass radius of the GC. We removed detected point sources from the data to extract spectra from diffuse regions around Terzan 5. The Galactic background emission was modeled by a 2-temperature thermal component, which is typical for Galactic diffuse emission. We detected significant diffuse excess emission above the particle background level from the whole field-of-view. The surface brightness appears to be peaked at the GC center and decreases smoothly outwards. After the subtraction of particle and Galactic background, the excess spectrum of the diffuse emission between the half-mass radius and 3' can be described by a power-law model with photon index $\Gamma$ = 0.9$\pm$0.5 and a surface flux of F$_X$ = (1.17$\pm$0.16) 10$^{-7}$ erg s$^{-1}$ cm$^{-2}$ sr$^{-1}$ in the 1--7 keV band. We estimated the contribution from unresolved point sources to the observed excess to be negligible. The observations suggest that a purely thermal origin of the emission is less likely than a non-thermal scenario. However, from simple modeling we cannot identify a clearly preferred scenario.Comment: 6 pages, 4 figures, accepted for publication by A&