Comment: Bayesian Checking of the Second Level of Hierarchical Models: Cross-Validated Posterior Predictive Checks Using Discrepancy Measures

Comment: Bayesian Checking of the Second Level of Hierarchical Models [arXiv:0802.0743]Comment: Published in at http://dx.doi.org/10.1214/07-STS235B the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Quasiparticles in the XXZ model

The coordinate Bethe ansatz solutions of the XXZ model for a one-dimensional spin-1/2 chain are analyzed with focus on the statistical properties of the constituent quasiparticles. Emphasis is given to the special cases known as XX, XXX, and Ising models, where considerable simplifications occur. The XXZ spectrum can be generated from separate pseudovacua as configurations of sets of quasiparticles with different exclusion statistics. These sets are complementary in the sense that the pseudovacuum of one set contains the maximum number of particles from the other set. The Bethe ansatz string solutions of the XXX model evolve differently in the planar and axial regimes. In the Ising limit they become ferromagnetic domains with integer-valued exclusion statistics. In the XX limit they brake apart into hard-core bosons with (effectively) fermionic statistics. Two sets of quasiparticles with spin 1/2 and fractional statistics are distinguished, where one set (spinons) generates the XXZ spectrum from the unique, critical ground state realized in the planar regime, and the other set (solitons) generates the same spectrum from the twofold, antiferromagnetically ordered ground state realized in the axial regime. In the Ising limit, the solitons become antiferromagnetic domain walls.Comment: 6 figure

Distribution, relative abundance and developmental morphology of paralarval cephalopods in the Western North Atlantic Ocean

Paralarval and juvenile cephalopods collected in plankton samples on 21 western North Atlantic cruises were identified and enumerated. The 3731 specimens were assigned to 44 generic and specific taxa. This paper describes their spatial and temporal distributions and their developmental morphology. The smallest paralarvae recognized for a number of species are identified and illustrated. The two most abundant and most frequently collected taxa were identifiable to species based on known systematic characters of young, as well as on distribution of the adults. These were the neritic squids Loligo pealeii and Illex illecebrosus collected north of Cape Hatteras, both valuable fishery resources. Other abundant taxa included two morphotypes of ommastrephids, at least five species of enoploteuthids, two species of onychoteuthids, and unidentified octopods. Most taxa were distributed widely both in time and in space, although some seasonal and mesoscale-spatial patterns were indicated. The taxa that appeared to have distinct seasonal distribution included most of the neritic species and, surprisingly, the young of the bathypelagic cranchiids. In eight seasonal cruises over the continental shelf of the middle U.S. Atlantic states, neritic taxa demonstrated approximately the same seasonal patterns during two consecutive years. Interannual differences in the oceanic taxa collected on the shelf were extreme. The highest abundance and diversity of planktonic cephalopods in the oceanic samples were consistently found in the vicinity of the Gulf Stream. Only eight of the oceanic taxa appeared to have limited areal distributions, compared with twelve taxa that were found throughout the western North Atlantic regions sampled in this study. Many taxa, however, were not collected frequently enough to describe seasonal or spatial patterns. Comparisons with published accounts of other cephalopod surveys indicate both strengths and weaknesses in various sampling techniques for capturing the young of oceanic cephalopods. Enoploteuthids were abundant both in our study and in other studies using midwater trawls in several areas of the North Atlantic. Thus, this family probably is adequately sampled over its developmental range. In contrast, octopoteuthids and chtenopterygiids are rare in collections made by small to medium-sized midwater trawls but are comparatively common in plankton samples. For families that are relatively common in plankton samples, paralarval abundance, derived similarly to the familiar ichthyoplankton surveys of fisheries science, may be the most reliable method of gathering data on distribution and abundance. (PDF file contains 58 pages.

On the Geometry of Moduli Space of Polarized Calabi-Yau manifolds

In this paper, we study the Chern classes on the moduli space of polarized Calabi-Yau manifolds. We prove that the integrations of the invariants of the curvature of the Weil-Petersson metric are finite. In some special cases, they are even rational numbers

Creating a Supportive Culture for Online Teaching: A Case Study of a Faculty Learning Community

This case study describes the creation of a supportive culture for online teaching at a western university that was transitioning to a new learning management system. The case study highlighted the creation of a faculty learning community as one strategy to address the challenge of faculty working through a change process. The faculty learning community provided a space for the development of best practices in teaching, drawing from the pedagogical experiences of teachers from diverse disciplines. The learning community also provided a venue for expanding the technical knowledge level of faculty members with a range of comfort levels with varied technologies

Energy-Efficient Machining Process Analysis and Optimisation Based on BS EN24T Alloy Steel as Case Studies

Computer Numerical Controlled (CNC) machining, which is one of the most widely-deployed manufacturing techniques, is an energy-intensive process. It is important to develop energy-efficient CNC machining strategies to achieve the overall goal of sustainable manufacturing. Due to the complexity of machining parameters, it is challenging to develop effective modelling and optimisation approaches to implement energy-efficient CNC machining. To address the challenge, in this paper, BS EN24T alloy (AISI 4340) has been used as a case study to conduct energy-efficient analysis and optimisation. Using a combination of experimentation and Taguchi analysis, the impact of the key machining parameters of CNC machining processes on energy consumption has been investigated in detail. A multi-objective optimisation model has been formulated, and a novel improved multi-swarm Fruit Fly optimisation algorithm (iMFOA) has been developed to identify optimal solutions. Case studies and algorithm benchmarking have been conducted to validate the effectiveness of the optimisation approach. The relationships between energy consumption and key machining parameters (e.g., cutting speed, feed per tooth, engagement depth) have been analysed to support process planners in implementing energy-saving measures efficiently. The optimisation approach developed is effective in fine-tuning key parameters for enhancing energy efficiency while meeting other technical requirements of production