منابع مشابه
Quaternionic Product of Circles and Cycles and Octonionic Product for Pairs of Circles
This paper concerns with a product of circles induced by the quaternionic product considered in a projective manner. Several properties of this composition law are derived and on this way we arrive at some special numbers as roots or powers of unit. We extend this product to cycles as oriented circles and to pairs of circles by using the algebra of octonions. Three applications of the given pro...
متن کاملQuality Ladders, Competition and Endogenous Growth
We examine a theory of competitive innovation in which new ideas are introduced only when diminishing returns to the use of existing ideas sets in. After an idea is introduced, the knowledge capital associated with that idea expands, and its value falls. Once the value falls far enough, it becomes profitable to introduce a new idea. The resulting theory is consistent with fixed costs of innovat...
متن کاملThe Long and Short (of) Quality Ladders∗
Prices are typically used as proxies for countries’ export quality. I relax this strong assumption by exploiting both price and quantity information to estimate the quality of products exported to the U.S. Higher quality is assigned to products with higher market shares conditional on price. The estimated qualities reveal substantial heterogeneity in product markets’ scope for quality different...
متن کاملQuantum Phase Transitions and Matrix Product States in Spin Ladders
X iv :q ua nt -p h/ 06 12 20 7v 1 2 5 D ec 2 00 6 Quantum Phase Transitions and Matrix Product States in Spin Ladders M. Asoudeh,∗ V. Karimipour†,‡ and A. Sadrolashrafi§ Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran, Iran (Dated: December 28, 2006) Abstract We investigate quantum phase transitions in ladders of spin 1/2 particles by engineering suitable mat...
متن کاملCompressing Product Development Cycles
• Cost saving The gun turret drive on a combat vehicle presents a very complex design challenge. When the vehicle travels over rough terrain, the gun turret drive compensates for the vehicle’s motion and keeps the gun pointed precisely at its target with 99.5% accuracy. In the past, General Dynamics Land Systems (GDLS) engineers used separate simulations to evaluate different aspects of the gun...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Quarterly Journal of Economics
سال: 1991
ISSN: 0033-5533
DOI: 10.2307/2937947