Should I make or should I buy? Innovation strategies and governance structures in the Italian food sector

This paper analyses the “make or buy” decision of food firms applied to innovation strategy using 389 Italian food firms data from the Unicredit 2007 database. We develop a set of hypothesis from three theoretical perspectives such as transaction cost economics, strategic management and resource-based view. Our paper aims at highlight whether or not different firm’s features can be linked to the decision to make or buy. We found out that these two decisions are positively interlinked. Moreover we also found out that it is difficult to indicate a clear-cut behaviour for the Italian food firms if we refer to making or buying decisions. We discuss these results and use them to bring some interesting outcomes to discuss managerial implications and/or policy interventions in this highly strategic domain

A static cost analysis for a higher-order language

We develop a static complexity analysis for a higher-order functional language with structural list recursion. The complexity of an expression is a pair consisting of a cost and a potential. The former is defined to be the size of the expression's evaluation derivation in a standard big-step operational semantics. The latter is a measure of the "future" cost of using the value of that expression. A translation function tr maps target expressions to complexities. Our main result is the following Soundness Theorem: If t is a term in the target language, then the cost component of tr(t) is an upper bound on the cost of evaluating t. The proof of the Soundness Theorem is formalized in Coq, providing certified upper bounds on the cost of any expression in the target language.Comment: Final versio

Ternary cluster decay within the liquid drop model

Longitudinal ternary and binary fission barriers of $^{36}$Ar, $^{56}$Ni and $^{252}$Cf nuclei have been determined within a rotational liquid drop model taking into account the nuclear proximity energy. For the light nuclei the heights of the ternary fission barriers become competitive with the binary ones at high angular momenta since the maximum lies at an outer position and has a much higher moment of inertia.Comment: Talk presented at the 9th International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTERS'07

Rotational velocities of A-type stars II. Measurement of vsini in the northern hemisphere

This work is the second part of the set of measurements of vsini for A-type stars, begun by Royer et al. (2002). Spectra of 249 B8 to F2-type stars brighter than V=7 have been collected at Observatoire de Haute-Provence (OHP). Fourier transforms of several line profiles in the range 4200--4600 A are used to derive vsini from the frequency of the first zero. Statistical analysis of the sample indicates that measurement error mainly depends on vsini and this relative error of the rotational velocity is found to be about 5% on average. The systematic shift with respect to standard values from Slettebak et al. (1975), previously found in the first paper, is here confirmed. Comparisons with data from the literature agree with our findings: vsini values from Slettebak et al. are underestimated and the relation between both scales follows a linear law: vsini(new) = 1.03 vsini(old) + 7.7. Finally, these data are combined with those from the previous paper (Royer et al. 2002), together with the catalogue of Abt & Morrell (1995). The resulting sample includes some 2150 stars with homogenized rotational velocities.Comment: 16 pages, includes 13 figures, accepted in A&

Probing viscoelastic properties of a thin polymer film sheared between a beads layer and quartz crystal resonator

We report measurements of viscoelastic properties of thin polymer films of 10-100 nm at the MHz range. These thin films are confined between a quartz crystal resonator and a millimetric bead layer, producing an increase of both resonance frequency and dissipation of the quartz resonator. The shear modulus and dynamic viscosity of thin films extracted from these measurements are consistent with the bulk values of the polymer. This modified quartz resonator provides an easily realizable and effective tool for probing the rheological properties of thin films at ambient environment.Comment: submitted to ap

The perturbed sublimation rim of the dust disk around the post-AGB binary IRAS08544-4431

Context: Post-Asymptotic Giant Branch (AGB) binaries are surrounded by stable dusty and gaseous disks similar to the ones around young stellar objects. Whereas significant effort is spent on modeling observations of disks around young stellar objects, the disks around post-AGB binaries receive significantly less attention, even though they pose significant constraints on theories of disk physics and binary evolution. Aims: We want to examine the structure of and phenomena at play in circumbinary disks around post-AGB stars. We continue the analysis of our near-infrared interferometric image of the inner rim of the circumbinary disk around IRAS08544-4431. We want to understand the physics governing this inner disk rim. Methods: We use a radiative transfer model of a dusty disk to reproduce simultaneously the photometry as well as the near-infrared interferometric dataset on IRAS08544-4431. The model assumes hydrostatic equilibrium and takes dust settling self-consistently into account. Results: The best-fit radiative transfer model shows excellent agreement with the spectral energy distribution up to mm wavelengths as well as with the PIONIER visibility data. It requires a rounded inner rim structure, starting at a radius of 8.25 au. However, the model does not fully reproduce the detected over-resolved flux nor the azimuthal flux distribution of the inner rim. While the asymmetric inner disk rim structure is likely to be the consequence of disk-binary interactions, the origin of the additional over-resolved flux remains unclear. Conclusions: As in young stellar objects, the disk inner rim of IRAS08544-4431 is ruled by dust sublimation physics. Additional observations are needed to understand the origin of the extended flux and the azimuthal perturbation at the inner rim of the disk.Comment: Accepted for publication in A&A, 13 figures, 13 page

Wave-number Selection by Target Patterns and Side Walls in Rayleigh-Benard Convection

We present experimental results for Rayleigh-Benard convection patterns in a cylindrical container with static side-wall forcing induced by a heater. This forcing stabilized a pattern of concentric rolls (a target pattern) with the central roll (the umbilicus) at the center of the cell after a jump from the conduction to the convection state. A quasi-static increase of the control parameter (epsilon) beyond 0.8 caused the umbilicus of the pattern to move off center. As observed by others, a further quasi-static increase of epsilon up to 15.6 caused a sequence of transitions. Each transition began with the displacement of the umbilicus and then proceeded with the loss of one convection roll at the umbilicus and the return of the umbilicus to a location near the center of the cell. Alternatively, with decreasing epsilon new rolls formed at the umbilicus but large umbilicus displacements did not occur. In addition to quantitative measurements of the umbilicus displacement, we determined and analyzed the entire wave-director field of each image. The wave numbers varied in the axial direction, with minima at the umbilicus and at the cell wall and a maximum at a radial position close to 2/3 Gamma. The wave numbers at the maximum showed hysteretic jumps at the transitions, but on average agreed well with the theoretical predictions for the wave numbers selected in the far field of an infinitely extended target pattern.Comment: ReVTeX, 11 pages, 16 eps figures include

Conserving Water in Irrigated Agriculture: The Economics and Valuation of Water Rights

The effective management of water resources in Alberta is crucial to sustainable agriculture, industrial development, and environmental management. The historical water allocation mechanism, administrative apportionment, has been viewed in recent years as ineffective and cumbersome. Accordingly, the revision of the Water Act in 1996, included an attempt to improve the efficiency of water allocation. By making the transfer of water rights possible, the revised Act provides many new options for water use and flexibility. The implications of transferable water rights in Alberta water policy must be carefully considered in order to determine the viability and suitability of such a system in the provincial context. This project examines some of the economic aspects of transferable water rights and the potential for effective water allocation by way of transfers in an Alberta setting. As a major part of this project, a hedonic price model, focusing on land values in southern Alberta, was constructed based on similar models, which have been used elsewhere to value water rights or agricultural products. The hedonic approach to market analysis uses the relationship between the price of land and the attributes of the land, such as water availability, soil quality and location, to explain differences in land prices. In this process, the hedonic model is used to estimate the implicit marginal price or value of each land attribute -- in our case, the marginal value of irrigation water. This value will provide us with an indirect estimate of the value of water rights in the region studied. An advantage of the technique is that it estimates the value that farmers express for irrigation water in the market place for land. Such values, then, give us an indication of the anticipated prices, which might prevail for water rights in southern Alberta. The focus of the study was an area of southern Alberta encompassing the counties of Wheatland, Newell, Cypress, Forty Mile, Taber, Warner, Lethbridge and Vulcan and the irrigation districts of Western, Eastern, St.Mary's, Taber, Lethbridge Northern, and portions of Raymond. Information was collected on the physical and economic characteristics of 230 land parcels, which were sold in this region in 1993 and early 1994. A crude comparison of the value of irrigated agricultural land and non-irrigated agricultural land in the sample reveals that irrigated land was worth, on average, $325 more per acre than non-irrigated land. In the ensuing analysis, it was estimated that the value of a parcel of land was determined largely by the buildings on it, the number of acres in the parcel, the proximity of the parcel to a major city (in this case Calgary or Lethbridge), and by the availability of irrigation water. In the hedonic model, the coefficient values of the variables included represent the marginal impact of each of these characteristics on land prices holding all other things constant. For example, the value of water rights represents the average difference between land values of farms that have access to irrigation and farms that do not. This study estimated that every dollar of improvements to farm buildings translates to a one cent increase in the per acre price of the land parcel, where the addition of one extra acre of land to a land parcel lowers the price per acre by$5.17 per acre. Land prices were seen to increase with the proximity of the parcel to large cities. Similarly, the results of the preferred model indicate that the implicit value of having access to irrigation water in southern Alberta is approximately $190 per acre, or, using the conventional estimate that irrigating one acre of land requires 1.5 acre feet of water, this translates to$126 per acre foot of irrigation water. Accordingly, it is revealed that the existence of water rights adds approximately 35% to the value of non-irrigated land. Since this value represents the implicit amount farmers are willing to pay for access to water, it could also be construed as an indirect measure of the value of water rights. From these results, it is reasonable to conclude that water rights do have a measurable impact on land values. Accordingly, proper incentives may be needed to ensure that water is used efficiently and not incorrectly treated as a relatively free or cheap good. One possible method of policy reform to achieve such a system would be the institution of a system of transferable water rights, permitting water to be traded, or effectively sold, at its market price or scarcity value. Further work was done to determine the potential effects of transferable water rights on the Eastern Irrigation District in southern Alberta. Farm budget information was used to gather information and create twelve representative farm types whose financial performance was analysed using linear programming with increasing water quantity constraints. The resulting productive water values were then used to imply potential reallocations of water among farm types and cropping systems. Analysis of the data gathered revealed that all representative farms faced downward sloping demand functions for water. The overall value of water for a 1% reduction ranged from $8 to$250 per acre foot, with the lowest value belonging to largely pasture operations and the highest value attributed to specialty crop producers. This large range in water values for the region indicates that there is sufficient heterogeneity within the EID to accommodate a transferable rights system. Further analysis of the data reveals that the implementation of a transfer system would result in water being transferred to specialty crop producers and the acreage devoted to specialty crops would increase. Small irrigated pasture operations and cereal crop producers would be the first to give up their water allocations under a transfer system. The analysis indicates that there is considerable potential for economic gains from water trade within this district, the main constraint being the market limitations to expanded specialty crop production. Using these two major studies and other sources, this report concludes with a brief evaluation of the economic advantages, disadvantages and other issues involved in instituting a system of transferable water rights in Alberta. Experience elsewhere, primarily in Australia and the western United States, strongly suggests that transferable water rights, despite some drawbacks and problems of implementation, can be a very worthwhile water policy tool. Now that such tradable water rights are permissible under the revised Water Resources Act of 1996, it is recommended that a pilot project involving transferable water rights be instituted in a water short basin or sub-basin in southern Alberta once a water management plan for that basin is completed.Resource /Energy Economics and Policy,

Charm and Beauty in Particle Physics

The spectra of states containing charmed and beauty quarks, and their regularities, are reviewed.Comment: 29 pages, LaTeX, 10 EPSF figures submitted separately. Presented at CERN in September, 1994 at a symposium in honor of Andre Martin To be submitted to Comments on Nuclear and Particle Physic

Making On-Demand Routing Efficient with Route-Request Aggregation

In theory, on-demand routing is very attractive for mobile ad hoc networks (MANET), because it induces signaling only for those destinations for which there is data traffic. However, in practice, the signaling overhead of existing on-demand routing protocols becomes excessive as the rate of topology changes increases due to mobility or other causes. We introduce the first on-demand routing approach that eliminates the main limitation of on-demand routing by aggregating route requests (RREQ) for the same destinations. The approach can be applied to any existing on-demand routing protocol, and we introduce the Ad-hoc Demand-Aggregated Routing with Adaptation (ADARA) as an example of how RREQ aggregation can be used. ADARA is compared to AODV and OLSR using discrete-event simulations, and the results show that aggregating RREQs can make on-demand routing more efficient than existing proactive or on-demand routing protocols