Fixed Fee Licenses and Welfare Reducing Innovation: A Note

This note shows that the fixed fee oligopolistic license model developed by Kamien and Tauman (1986) yields the result that the private returns from innovation can be greater than the social returns when the number of firms in the industry is equal to or larger than 3. This result implies that an innovation does not always improve welfare, even when it is profitable for the innovator. We also show that the auction license model yields the same result as the fixed fee.

Specific-heat study on successive magnetic transitions in α-Dy2S3 single crystals under magnetic fields

Specific heat measurements in magnetic fields have been performed on !-Dy2S3 single crystal that shows successive magnetic transitions at TN1 = 11.4 K and TN2 = 6.4 K. The specific heat in no magnetic field exhibits sharp peaks at both temperatures of TN1 and TN2.The change of magnetic entropy across each transition is estimated as Rln2/2 per mol-Dy,which suggests magnetic moments on only one Dy site between two crystallographically inequivalent Dy sites order at each transition temperature. When the magnetic field is applied along the b-axis of the orthorhombic system, two peaks of the specific heat shift toward lower temperatures. On the other hand, the magnetic field perpendicular to the b-axis shifts the peaks toward higher temperatures. The TN1 shifts to 9.6 K (H// b) and 12.5 K (H⊥b) under the magnetic field of 2 T. The peak of TN2 broadens gradually with increasing magnetic field for each direction, and the peak is consequently obscure under the field of 2 T

A Search for Water Masers in the Saturnian System

We searched for H2O 6(1,6)-5(2,3) maser emission at 22.235 GHz from several Saturnian satellites with the Nobeyama 45m radio telescope in May 2009. Observations were made for Titan, Hyperion, Enceladus and Atlas, for which Pogrebenko et al. (2009) had reported detections of water masers at 22.235 GHz, and in addition for Iapetus and other inner satellites. We detected no emission of the water maser line for all the satellites observed, although sensitivities of our observations were comparable or even better than those of Pogrebenko et al.. We infer that the water maser emission from the Saturnian system is extremely weak, or sporadic in nature. Monitoring over a long period and obtaining statistical results must be made for the further understanding of the water maser emission in the Saturnian system.Comment: 8 pages, 2 figures, accepted for publication in PASJ (Letter

Incentives in R&D and the Optimization of Patent Length-The structure of the Nordhaus model: A reexamination-

This paper reconsiders the theory of the optimal patent length developed by Nordhaus(1969), and, by using Takahashi(2007), sheds new light on its implications for how best to benefit society. Patents, by protecting innovators from imitation, give them the incentive to bear the costs of their development efforts, and in doing so benefit society. However, it also works against benefitting society, since it makes the market monopolistic. This tradeoff can be mitigated by choosing the patent length carefully. The Nordhaus model successfully implies that, for maximizing social benefits, the patent length should be terminated in a finite period. He obtains this theoretical implication by assuming that any privately profitable innovation will benefit society, an idea that was first presented in Arrow(1962). In this article, these discussions are explained fully. Finally, this paper also shows that the optimal patent length may be zero for a minor innovation. This conjecture is derived from Takahashi(2007), and shows that Nordhaus\u27 assumption does not hold when the innovation occurs in an oligopolistic market and the size of innovation is small

Formation mechanism of plateau, rapid fall and tail in phosphorus diffusion profile in silicon based on the pair diffusion models of vacancy mechanism and interstitial mechanism

P diffuses predominantly by the interstitial mechanism in Si. Assuming that there is a strong binding energy between P and I, therefore, the basic process of P diffusion is the diffusion of (PI), where I and (PI) represent self-interstitials and P-I pairs, respectively. In the high-P-concentration region, excess I is generated by the dissociation of (PI) and the limiting process of P diffusion depends on whether or not excess I is controlled. That is, if the concentration of excess I decreases relatively to the equilibrium I concentration due to the effect of the decrease in quasi self-interstitial formation energy, or if excess I is removed by the recombination with vacancies, P diffuses fast and the plateau is formed; if not, P diffuses slowly and the rapid fall is formed. In the tail region, the P concentration is low and the limiting process of P diffusion is the basic process of P diffusion, that is, the diffusion of (PI). Excess I generated in the high-P-concentration region diffuses into the low-P-concentration region, and I is supersaturated there. Therefore, the concentration of (PI) increases, resulting in the fast diffusion of P and the formation of the tail

Cooperative non-cell and cell autonomous regulation of Nodal gene expression and signaling by Lefty/Antivin and Brachyury in Xenopus

AbstractDynamic spatiotemporal expression of the nodal gene and its orthologs is involved in the dose-dependent induction and patterning of mesendoderm during early vertebrate embryogenesis. We report loss-of-function studies that define a high degree of synergistic negative regulation on the Xenopus nodal-related genes (Xnrs) by extracellular Xenopus antivin/lefty (Xatv/Xlefty)-mediated functional antagonism and Brachyury-mediated transcriptional suppression. A strong knockdown of Xlefty/Xatv function was achieved by mixing translation- and splicing-blocking morpholino oligonucleotides that target both the A and B alloalleles of Xatv. Secreted and cell-autonomous inhibitors of Xnr signaling were used to provide evidence that Xnr-mediated induction was inherently long-range in this situation in the large amphibian embryo, essentially being capable of spreading over the entire animal hemisphere. There was a greater expansion of the Organizer and mesendoderm tissues associated with dorsal specification than noted in previous Xatv knockdown experiments in Xenopus, with consequent exogastrulation and long-term maintenance of expanded axial tissues. Xatv deficiency caused a modest animal-ward expansion of the marginal zone expression territory of the Xnr1 and Xnr2 genes. In contrast, introducing inhibitory Xbra-EnR fusion constructs into Xatv-deficient embryos caused a much larger increase in the level and spatial extent of Xnr expression. However, in both cases (Xatv/Xlefty-deficiency alone, or combined with Xbra interference), Xnr2 expression was constrained to the superficial cell layer, suggesting a fundamental tissue-specific competence in the ability to express Xnrs, an observation with direct implications regarding the induction of endodermal vs. mesodermal fates. Our experiments reveal a two-level suppressive mechanism for restricting the level, range, and duration of Xnr signaling via extracellular inhibition by Xatv/Xlefty coupled with potent indirect transcriptional repression by Xbra

Time-Efficient Light-Field Acquisition Using Coded Aperture and Events

We propose a computational imaging method for time-efficient light-field acquisition that combines a coded aperture with an event-based camera. Different from the conventional coded-aperture imaging method, our method applies a sequence of coding patterns during a single exposure for an image frame. The parallax information, which is related to the differences in coding patterns, is recorded as events. The image frame and events, all of which are measured in a single exposure, are jointly used to computationally reconstruct a light field. We also designed an algorithm pipeline for our method that is end-to-end trainable on the basis of deep optics and compatible with real camera hardware. We experimentally showed that our method can achieve more accurate reconstruction than several other imaging methods with a single exposure. We also developed a hardware prototype with the potential to complete the measurement on the camera within 22 msec and demonstrated that light fields from real 3-D scenes can be obtained with convincing visual quality. Our software and supplementary video are available from our project website.Comment: Accepted to IEEE/CVF Computer Vision and Pattern Recognition Conference (CVPR) 202