Mapping of the vehicle routing processes in timber transport

Transportation represents 10-15 % of wood supply costs. It is therefore important to improve efficiency in the transport system to decrease these costs. The aim of this study is to map the timber vehicle routing processes used by a sample of timber hauling contractors and to identify possible links between the vehicle routing process and service and economic variables. The study was carried out at Södra Skog in autumn 2008. 15 timber hauling contractors were sampled and interviewed about their work with timber transports. A base model for a timber vehicle routing process was mapped. The main steps in the timber vehicle routing process were: Data collection - Trucking company receives transport orders and information from transport administrators Preparatory planning - The trucking company prepares an overview of possible transport routes Main planning decisions - The trucking company takes into consideration the factors that restrict the execution Resource allocation – The trucking company takes into consideration the factors that determine the coordination of labour. The main variants of the base model were also mapped and compared with respect to their service and economic variables. The two most significant deviations from the base model concern the occurrence of follow-up of delivery quotas in Preparatory planning and certain combinations of activities in Main planning decisions. In the results of this study increasing service levels are negatively related to profitability. Follow-up of delivery quotas is linked to increasing service level but negatively related to profitability. This is because Follow-up of delivery quotas directs the trucking company to specific landings and (hence) restricts the routing planning. In Main planning decisions there are restrictions such as availability and the volumes of the landings. Inclusion of these restrictions in routing is linked to both higher service levels and profitability. Profitability is also affected by how many hours each lorry is used per year. Higher capacity utilization than 4000 hrs/yr per truck is linked to lower profitability

Social capital and self-rated health – a study of temporal (causal) relationships

Despite the vast amount of research over the past fifteen years, there is still lively debate surrounding the role of social capital on individual health outcomes. This seems to stem from a lack of consistency regarding the definition, measurement and plausible theories linking this contextual phenomenon to health. We have further identified a knowledge gap within this field - a distinct lack of research investigating temporal relationships between social capital and health outcomes. To remedy this shortfall, we use four waves of the British Household Panel Survey to follow the same individuals (N = 8114) between years 2000 and 2007. We investigate temporal relationships and association between our outcome variable self-rated health (SRH) and time-lagged explanatory variables, including three individual-level social capital proxies and other well-known health determinants. Our results suggest that levels of the social capital proxy ‘generalised trust’ at time point (t-1) are positively associated with SRH at subsequent time point (t), even after taking into consideration levels of other well-known health determinants (such as smoking status) at time point (t-1). That we investigate temporal relationships at four separate occasions over the seven year period lends considerable weight to our results and the argument that generalised trust is an independent predictor of individual health. However, lack of consensus across a variety of disciplines as to what generalised trust is believed to measure creates ambiguity when attempting to identify possible pathways from higher trust to better health

Generalized Kahler Geometry from supersymmetric sigma models

We give a physical derivation of generalized Kahler geometry. Starting from a supersymmetric nonlinear sigma model, we rederive and explain the results of Gualtieri regarding the equivalence between generalized Kahler geometry and the bi-hermitean geometry of Gates-Hull-Rocek. When cast in the language of supersymmetric sigma models, this relation maps precisely to that between the Lagrangian and the Hamiltonian formalisms. We also discuss topological twist in this context.Comment: 18 page

First-order supersymmetric sigma models and target space geometry

We study the conditions under which N=(1,1) generalized sigma models support an extension to N=(2,2). The enhanced supersymmetry is related to the target space complex geometry. Concentrating on a simple situation, related to Poisson sigma models, we develop a language that may help us analyze more complicated models in the future. In particular, we uncover a geometrical framework which contains generalized complex geometry as a special case.Comment: 1+19 pages, JHEP style, published versio

T-duality and Generalized Complex Geometry

We find the explicit T-duality transformation in the phase space formulation of the N=(1,1) sigma model. We also show that the T-duality transformation is a symplectomorphism and it is an element of O(d,d). Further, we find the explicit T-duality transformation of a generalized complex structure in this model. We also show that the extended supersymmetry of the sigma model is preserved under the T-duality.Comment: 18 pages; added references; published versio

On small tension p-branes

This paper deals with p-branes with small but non-zero tension. We prove the existence of canonical transformations, within a perturbation theory, that link specific geometries of p-branes to solvable theories, namely string-like and particle-like theories. The specific shapes correspond to stretched configurations. For configurations linked to string-like theories one will upon quantization get a critical dimension of (25+p).Comment: 7 page

On-board Clutch Slippage Detection and Diagnosis in Heavy Duty Machine

In order to reduce unnecessary stops and expensive downtime originating from clutch failure of construction equipment machines; adequate real time sensor data measured on the machine in combination with feature extraction and classification methods may be utilized. This paper presents a framework with feature extraction methods and an anomaly detection module combined with Case-Based Reasoning (CBR) for on-board clutch slippage detection and diagnosis in heavy duty equipment. The feature extraction methods used are Moving Average Square Value Filtering (MASVF) and a measure of the fourth order statistical properties of the signals implemented as continuous queries over data streams. The anomaly detection module has two components, the Gaussian Mixture Model (GMM) and the Logistics Regression classifier. CBR is a learning approach that classifies faults by creating a new solution for a new fault case from the solution of the previous fault cases. Through use of a data stream management system and continuous queries (CQs), the anomaly detection module continuously waits for a clutch slippage event detected by the feature extraction methods, the query returns a set of features, which activates the anomaly detection module. The first component of the anomaly detection module trains a GMM to extracted features while the second component uses a Logistic Regression classifier for classifying normal and anomalous data. When an anomaly is detected, the Case-Based diagnosis module is activated for fault severity estimation

Breast cancer genetic risk profile is differentially associated with interval and screen-detected breast cancers

Background: Polygenic risk profiles computed from multiple common susceptibility alleles for breast cancer have been shown to identify women at different levels of breast cancer risk. We evaluated whether this genetic risk stratification can also be applied to discriminate between screen-detected and interval cancers, which are usually associated with clinicopathological and survival differences. Patients and methods: A 77-SNP polygenic risk score (PRS) was constructed for breast cancer overall and by estrogen-receptor (ER) status. PRS was inspected as a continuous (per standard deviation increment) variable in a case-only design. Modification of the PRS by mammographic density was evaluated by fitting an additional interaction term. Results: PRS weighted by breast cancer overall estimates was found to be differentially associated with 1,865 screen-detected and 782 interval cancers in the LIBRO-1 study (age-adjusted ORperSD [95% confidence interval]=0.91 [0.83-0.99], p=0.023). The association was found to be more significant for PRS weighted by ER-positive breast cancer estimates (ORperSD=0.90 [0.82-0.98], p=0.011). This result was corroborated by two independent studies (combined ORperSD=0.87 [0.76-1.00], p=0.058) with no evidence of heterogeneity. When enriched for “true” interval cancers among nondense breasts, the difference in the association with PRS in screen-detected and interval cancers became more pronounced (ORperSD=0.74 [0.62-0.89], p=0.001), with a significant interaction effect between PRS and mammographic density (pinteraction=0.017). Conclusion: To our knowledge, this is the first report looking into the genetic differences between screendetected and interval cancers. It is an affirmation that the two types of breast cancer may have unique underlying biology.Swedish Research CouncilSwedish Cancer SocietyStockholm County CouncilBreast Cancer Theme Centre Consortium (BRECT)Accepte