Source separation using a criterion based on second-orderstatistics

It is often assumed that blind separation of dynamically mixed sources cannot be done with second-order statistics. It is shown that separation of dynamically mixed sources indeed can be performed using second-order statistics only. A criterion based on second-order statistics for the purpose of separating crosswise mixtures is stated. The criterion is used in order to derive a gradient-based separation algorithm, as well as a Newton-type separation algorithm. The uniqueness of the solution representing the separation is also investigated. This reveals that (1) the channel system is parameter identifiable under weak conditions, and (2) if the sources have the same color, there exists at most two solutions. The local convergence behavior of the proposed algorithm is studied and reveals a sufficient condition for local convergence. Furthermore, the estimates of the channel system are shown to be consistent or to locally minimize the criterion     

The response of mountain pine beetle (Dendroctonus ponderosae) to lodgepole pine trees baited with verbenone and exo-brevicomin

exo-brevicomin, a multifunctional pheromone of the mountain pine beetle,Dendroctonus ponderosae, was tested at release rates of 0.5 and 2.5 mg/day alone and in combination with the antiaggregation pheromone verbenone against unbaited controls. Significantly more lodgepole pinePinus contorta var.latifolia trees were attacked, and at higher densities, with both release rates ofexo-brevicomin than with all other treatments. Verbenone significantly reduced the response of mountain pine beetles toexo-brevicomin. Verbenone alone did not reduce the number of trees attacked by mountain pine beetle or the attack density when compared to the unbaited controls.     

An Improved Model for the Longitudinal Peak Strain in the Flange of a Roll Formed U‐Channel developed by FE‐Analyses

Today one can find cold roll forming (CRF) products in many applications, for example vehicles, furniture and in the building industry. Though CRF is a well known sheet metal process, it is still not entirely understood due to the geometrically complex forming. There are several computer aided engineering (CAE) programs on the market that can assist the tool maker when designing a new CRF machine. However, they are often based on simple formulas when predicting the stress and the strain in the strip. The main objective of this study is to improve formulas for the longitudinal peak membrane strain and the deformation length when a U‐channel is formed. These are important since they can be used to determine the number of forming steps and the distance between them. A two‐level factorial design is done using the finite element analysis to investigate which parameters affect the peak strain and the deformation length. The parameters are then used to build models for the peak strain and the deformation length.     

A Comparison of Presentation Methods for Reading on Mobile Phones

A study compares two methods of reading text-based content on mobile phones: traditional scroll-based reading and Rapid Serial Visual Presentation, which displays words rapidly in a sequence. University students used a prototype called Feedo to test both methods, and their reading comprehension, efficiency, and preference ratings were measured. The results show that efficiency increases with fast RSVP, comprehension is equal, and preference rating is lower than with self-paced scroll.     

Adaptive functioning following traumatic brain injury and orthopedic injury: a controlled study

BACKGROUND: In an effort to intensify osteosarcoma therapy, systemic ifosfamide was added pre- and postoperatively to an already aggressive three-drug regimen. In a subgroup of patients, loco-regional treatment intensification was attempted by using the intraarterial route to give cisplatin. PATIENTS AND METHODS: Patients < or = 40 years at diagnosis of a localised, de novo high-grade central extremity osteosarcoma were eligible for inclusion into study COSS-86 if registered within three weeks from biopsy. Doxorubicin, high-dose methotrexate, and cisplatin were given to all patients. Patients who fulfilled one or more of three defined high-risk criteria received early systemic treatment intensification by adding ifosfamide as the fourth agent. Preoperatively, these high-risk patients received cisplatin either intraarterially or intravenously. RESULTS: 171 eligible patients were entered, of which 128 were stratified into the high-risk group. When all 171 were analysed by intention-to-treat, actuarial overall and event-free survival rates at ten years were 72% and 66%, respectively. No benefit of intraarterial cisplatin application was detected. Cumulative treatment toxicity was considerable. CONCLUSIONS: In a multicenter setting, intensive treatment of osteosarcoma according to protocol COSS-86 led to long-term disease-free survival for two thirds of patients. We saw no benefit of using the intraarterial route to administer cisplatin.     

Intercorrelations among plasma high density lipoprotein,obesity and triglycerides in a normal population

The interrelationships among fatness measures, plasma triglycerides and high density lipoproteins (HDL) were examined in 131 normal adult subjects: 38 men aged 27–46, 40 men aged 47–66, 29 women aged 27–46 and 24 women aged 47–66. None of the women were taking estrogens or oral contraceptive medication. The HDL concentration was subdivided into HDL_2b, HDL_2a and HDL₃ by a computerized fitting of the total schlieren pattern to reference schlieren patterns. Anthropometric measures employed included skinfolds at 3 sites, 2 weight/height indices and 2 girth measurements. A high correlation was found among the various fatness measures. These measures were negatively correlated with total HDL, reflecting the negative correlation between fatness measures and HDL₂ (as the sum of HDL_2a and_2b). Fatness measures showed no relationship to HDL₃. There was also an inverse correlation between triglyceride concentration and HDL₂. No particular fatness measure was better than any other for demonstrating the inverse correlation with HDL but multiple correlations using all of the measures of obesity improved the correlations. Partial correlations controlling for fatness did not reduce any of the significant correlations between triglycerides and HDL₂ to insignificance. The weak correlation between fatness and triglycerides was reduced to insignificance when controlled for HDL₂. Presented (in part) at the Annual Meeting of the Oil Chemists' Society in St. Louis, MO, May 1978.     

Rethinking competence systems for knowledge-based organizations

Existing competence systems are based on a rationalistic view of competence. While these competence systems might work in job-based organizations, we argue that in more dynamic settings, such as in knowledge-based organizations, the interest-informed actions that capture the emergent competencies of tomorrow require different types of information technology support. The main objective of this paper is to elaborate on the possibilities and implications of using interest-activated technology as a design rationale for competence systems. This paper is based on an action case study of an implemented interest-activated Intranet recommender system prototype at Volvo Information Technology AB in Gothenburg, Sweden. On the basis of how organizational members used this prototype to find information they were interested in, our research team was able to inquire into how personal interest, embodied in information-seeking activities, could be a means for identifying competence. Building on the relation between personal interest and competence, we discuss competence systems design and spell out explicit implications for managerial practice in knowledge-based organizations.