Extending the p-cycle concept to path segment protection for span and node failure recovery

The paper introduces an extension to the method of p-cycles for network protection. The p-cycle concept is generalized to protect path segments of contiguous working flow, not only spans that lie on the cycle or directly straddle the p-cycle. The original span protecting use of the p-cycle technique is extend to include path protection or protection of any flow segment along a path. It also gives an inherent means of protecting working flows that transit a failed node. We use integer linear programming to study the new concept and determine its inherent capacity requirements relative to prior p-cycle designs and other types of efficient mesh-survivable networks. Results show that path-segment-protecting p-cycles ("flow p-cycles") have capacity efficiency near that of the shared backup path-protection (SBPP) scheme currently favored for optical networking. Because its protection paths are fully preconnected and because it protects path segments (not entire paths), it has the potential for both higher speed and higher availability than SBPP. We also develop capacity optimization models to support 100% restoration of transiting flows through failed nodes. Only a very small additional spare capacity is needed to achieve both 100% span and intermediate node-failure restorabilities, and a very high transiting traffic restorability can be accomplished for node failure restorability given spare capacity only for span-failure protection. An immediate practical application is to suggest the use of flow p-cycles to protect transparent optical express flows through a regional network.     

From business reengineering to business process change management:a longitudinal study of trends and practices

Business process reengineering has been prominently discussed and implemented in a large number of firms around the world. While the notion of radical change is intuitively appealing to “fix” organizational woes, it has not always met with the degree of success originally claimed by its many proponents. This article studies the evolution of the reengineering concept and its evolution toward the broader notion of process change management. Reported here are the results of two studies that explore reengineering from a project implementation perspective and an organizational perspective at two different points in time. The results show remarkable consistency in the importance of nontechnology management issues concerning strategy, change and people. Further, the notion of continuous change seems to be becoming,more important. The study provides a foundation for identifying key variables that can be studied in order to effectively manage this multifaceted phenomenon     

Constitution of pinastric acid

New observations in support of the revised constitution for pinastric acid based on a study of its reactions with o-phenylene diamine, dimethylaniline, and oxidation with sodium periodate.     

Improvement of duty-cycle heating compensation in NMR spin relaxation experiments

To reliably measure NMR relaxation properties of macromolecules is a prerequisite for precise experiments that identify subtle variations in relaxation rates, as required for the determination of rotational diffusion anisotropy, CSA tensor determination, advanced motional modeling or entropy difference estimations. An underlying problem with current NMR relaxation measurement protocols is maintaining constant sample temperature throughout the execution of the relaxation series especially when rapid data acquisition is required. Here, it is proposed to use a combination of a heating compensation and a proton saturation sequence at the beginning of the NMR relaxation pulse scheme. This simple extension allows reproducible, robust and rapid acquisition of NMR spin relaxation data sets. The method is verified with (15)N spin relaxation measurements for human ubiquitin.     

Relativistic α-particles emitted in Fe-emulsion interactions at 1.7A GeV

Relativistic α-particles have been studied in 423 interactions of Fe in emulsion at 1.7A GeV. Comparisons of the observed angular distribution with that from ¹⁶O-emulsion reactions at 2.1A GeV reveal that more α-particles are observed at large angles in the Fe-emulsion reactions. The α-particles at large angles cannot be explained by fragmentation from a clean-cut spectator. Comparison of the experimental data with moving relativistic Boltzmann distributions shows that a single Boltzmann distribution cannot fit the fragmentation peak and the tail simultaneously. A thermal source (fireball) explaining the tail part of the distribution needs to be formed by a mechanism other than a simple clean-cut participant-spectator process. A large transverse momentum transfer to the spectator before fragmentation may explain the tail.     

Obtuse cones in Hilbert spaces and applications to partial differential equations

The positive cone K in a partially ordered Hilbert space is said to be obtuse with respect to the inner product if the dual cone $\text{K}{}^1\text{? K}$. Obtuseness of cones with respect to non-symmetric bilinear forms is also defined and characterized. These results are applied to the generalized Sobolev space associated with an elliptic boundary value problem, in particular to the question of determining the non-negativity of the Green's function. A notion of strict obtuseness is defined, characterized and applied to the question of strict positivity of the Green's function. Applications to positivity preserving semi-groups are also given.     

Random partial diffuser as beam splitter in a new,common path interferometer

Use of a random partial diffuser is suggested as a beam spitter. An aberration-free reference beam coaxial with the test beam is obtained when the latter converges on the diffuser. Based on this principle, an interferometer has been realised for absolute measurements with a sensitivity equal to that of a Mach-Zehnder interferometer. A large variety of optical components can be tested by this simple and inexpensive interferometer which could replace the already existing ones in optical workshops.