Model for the Benefit Analysis of ICT

The ratio between success and failure in ICT projects suggests a need for improved understanding of the ICTimplementations. New methods to evaluate the ICT projects are sought. While process modeling has been under way inorganizations for decades, this paper presents a new approach to analyzing benefits based on the introduction of ICT services.In our approach the success of ICT projects is evaluated by analyzing the productivity benefits they enable in the businessprocesses of the users. In its novel way, this paper points out the significant role of interacting processes and related actors.With the help of the Three Viewpoint Model (3VPM) and skill-matrix approaches the critical factors related to improvementbenefits can be found. Our tool allows analyzing and evaluating the output at the time even when the ICT project is notcompleted, also taking into account the dynamic nature of processes

Analysis and Performance Evaluation of the IEEE 802.16 ARQ Mechanism

The IEEE 802.16 standard defines the ARQ mechanismas a part of the MAC layer. The functioning of the ARQmechanism depends on a number of parameters. The IEEE802.16 specification defines them but it does not provide concrete values and solutions. This paper studies the key features and parameters of the 802.16 ARQ mechanism. In particular, we consider a choice for the ARQ feedback type, an algorithm to build block sequences, the ARQ feedback intensity, a scheduling of the ARQ feedbacks and retransmissions, the ARQ block rearrangement, ARQ transmission window and the ARQ block size. We ran simulation scenarios to study these parameters and how they impact the performance of application protocols. Thesimulation results reveal that the ARQ mechanism and its correct configuration play an important role in achieving reliable data transmission

Trajectories of mental health before and after old-age and disability retirement : a register-based study on purchases of psychotropic drugs

WOS:000308570400003OBJECTIVES: Retirement from paid work is a major life event facing increasingly large numbers of people in the coming years. We examined trajectories of mental health five years before and five years after old-age and disability retirement using data on purchases of psychotropic drugs. METHODS: The study included all employees from the City of Helsinki, Finland, retiring between 2000-2008 due to old age (N=4456) or disability (N=2549). Purchases of psychotropic drugs were analyzed in 20 3-month intervals before and after retirement using graphical methods and growth curve models. RESULTS: Old-age retirement was unrelated to purchases of psychotropic drugs. Among disability retirees, psychotropic medication tripled before retirement. The average increase was 0.95 [95% confidence interval (95% CI) 0.73-1.16] daily defined doses (DDD) 5-1.5 years before retirement; from 1.5 years until retirement it was 5.68 DDD (95% CI 5.33-6.03) for each 3-month interval. After disability retirement, purchases of antidepressants decreased on average by 0.40 DDD (95% CI 0.57-0.23) for each 3-month interval, those of hypnotics and sedatives increased by 0.30 DDD (95% CI 0.12-0.47), and no changes were seen for other psychotropic drugs. The changes before and after retirement were largest among those who retired due to mental disorders and those whose retirement had been granted as temporary. CONCLUSIONS: While no overall decrease in psychotropic medication after retirement was observed, purchases of antidepressants decreased after disability retirement. Long-term trajectories suggest that disability retirement might be prevented if mental health problems were tackled more efficiently earlier in the pre-retirement period.Peer reviewe

Strain-Stiffening of Agarose Gels

Strain-stiffening is one of the characteristic properties of biological hydrogels and extracellular matrices, where the stiffness increases upon increased deformation. Whereas strain-stiffening is ubiquitous in protein-based materials, it has been less observed for polysaccharide and synthetic polymer gels. Here we show that agarose, that is, a common linear polysaccharide, forms helical fibrillar bundles upon cooling from aqueous solution. The hydrogels with these semiflexible fibrils show pronounced strain-stiffening. However, to reveal strain-stiffening, suppressing wall slippage turned as untrivial. Upon exploring different sample preparation techniques and rheological architectures, the cross-hatched parallel plate geometries and in situ gelation in the rheometer successfully prevented the slippage and resolved the strain-stiffening behavior. Combining with microscopy, we conclude that strain-stiffening is due to the semiflexible nature of the agarose fibrils and their geometrical connectivity, which is below the central-force isostatic critical connectivity. The biocompatibility and the observed strain-stiffening suggest the potential of agarose hydrogels in biomedical applications.Peer reviewe

Working conditions as risk factors for disability retirement: a longitudinal register linkage study

WOS:000308534000001Peer reviewe

Carbon dioxide exchange of a perennial bioenergy crop cultivation on a mineral soil

One of the strategies to reduce carbon dioxide (CO2) emissions from the energy sector is to increase the use of renewable energy sources such as bioenergy crops. Bioenergy is not necessarily carbon neutral because of greenhouse gas (GHG) emissions during biomass production, field management and transportation. The present study focuses on the cultivation of reed canary grass (RCG, Phalaris arundinaceae L.), a perennial bioenergy crop, on a mineral soil. To quantify the CO2 exchange of this RCG cultivation system, and to understand the key factors controlling its CO2 exchange, the net ecosystem CO2 exchange (NEE) was measured during three years using the eddy covariance (EC) method. The RCG cultivation thrived well producing yields of 6200 and 6700 kg DW ha−1 in 2010 and 2011, respectively. Gross photosynthesis (GPP) was controlled mainly by radiation from June to September. Vapour pressure deficit (VPD), air temperature or soil moisture did not limit photosynthesis during the growing season. Total ecosystem respiration (TER) increased with soil temperature, green area index and GPP. Annual NEE was −262 and −256 g C m−2 in 2010 and 2011, respectively. Throughout the studied period, cumulative NEE was −575 g C m−2. When compared to the published data for RCG on an organic soil, the cultivation of this crop on a mineral soil had higher capacity to take up CO2 from the atmosphere.Non peer reviewe