Automorphism groups of countable algebraically closed graphs and endomorphisms of the random graph

We establish links between countable algebraically closed graphs and the endomorphisms of the countable universal graph $R$. As a consequence we show that, for any countable graph $\Gamma$, there are uncountably many maximal subgroups of the endomorphism monoid of $R$ isomorphic to the automorphism group of $\Gamma$. Further structural information about End $R$ is established including that Aut $\Gamma$ arises in uncountably many ways as a Sch\"{u}tzenberger group. Similar results are proved for the countable universal directed graph and the countable universal bipartite graph.Comment: Minor revision following referee's comments. 27 pages, 3 figure

Ozone recovery in the upper stratosphere from Umkehr measurement over Syowa, Antarctica

第3回極域科学シンポジウム/第35回極域気水圏シンポジウム 11月30日（金） 国立国語研究所 ２階ロビ

DPOS: A metalanguage and programming environment for parallel processors

Journal ArticleThe complexity and diversity of parallel programming languages and computer architectures hinders programmers in developing programs and greatly limits program portability. All MIMD parallel programming systems, however, address common requirements for process creation, process management, and interprocess communication. This paper describes and illustrates a structured programming system (DPOS) and graphical programming environment for generating and debugging high-level MIND parallel programs. DPOS is a metalanguage for defining parallel program networks based on the common requirements of distributed parallel computing that is portable across languages, modular, and highly flexible. The system uses the concept of stratification to separate process network creation and the control of parallelism form computational work. Individual processes are defined within the process object layer as traditional single threaded programs without parallel language constructs. Process networks and communication are defined graphically within the system layer at a high level of abstraction as recursive graphs. Communication is facilitated in DPOS by extending message passing semantics in several ways to implement highly flexible message passing constructs. DPOS processes exchange messages through bi-directional channel objects using guarded, buffered, synchronous and asynchronous communication semantics. The DPOS environment also generates source code and provides a simulation system for graphical debugging and animation of the programs in graph form

Using utilization profiles in allocation and partitioning for multiprocessor systems

Journal ArticleThe problems of multiprocessor partitioning and program allocation are interdependent and critical to the performance of multiprocessor systems. Minimizing resource partitions for parallel programs on partitionable multiprocessors facilitates greater processor utilization and throughput. The processing resource requirements of parallel programs vary during program, execution and are allocation dependent. Optimal resource utilization requires that resource requirements be modeled as variable over time. This paper investigates the use of program profiles in allocating programs and partitioning multiprocessor systems. An allocation method is discussed. The goals of this method are to (1) minimize program execution time, (2) minimize t h e total number of processors used, (3) characterize variation in processor requirements over the lifetime of a program, (4) to accurately predict the impact on run time of the number of processors available at any point in time and (5) to minimize fluctuations in processor requirements to facilitate efficient sharing of processors between partitions on a partitionable multiprocessor. An application to program partitioning is discussed that improves partition run times compared to other methods

A communication-ordered task graph allocation algorithm

technical reportThe inherently asynchronous nature of the data flow computation model allows the exploitation of maximum parallelism in program execution. While this computational model holds great promise, several problems must be solved in order to achieve a high degree of program performance. The allocation and scheduling of programs on MIMD distributed memory parallel hardware, is necessary for the implementation of efficient parallel systems. Finding optimal solutions requires that maximum parallelism be achieved consistent with resource limits and minimizing communication costs, and has been proven to be in the class of NP-complete problems. This paper addresses the problem of static allocation of tasks to distributed memory MIMD systems where simultaneous computation and communication is a factor. This paper discusses similarities and differences between several recent heuristic allocation approaches and identifies common problems inherent in these approaches. This paper presents a new algorithm scheme and heuristics that resolves the identified problems and shows significant performance benefits

What controls long-term Ozone changes other than Ozone-Depleting Substances in the Antarctic stratosphere?

In the upper stratosphere the inter-annual variability of ozone is mostly controlled by chemical reactions and is strongly influenced by the anthropogenic ozone-depleting substances (ODS). While at middle latitudes the ODS reached the maximum in the stratosphere by the end of 1990s, at high latitudes the turning in the growth rate of the ODS has been delayed by several years. Analysis of Umkehr observations helps to understand the influence of the ODS on ozone in the middle and upper stratosphere. We investigated the long-term trend in the upper stratospheric ozone over the Antarctic using re-processed Umkehr data at Syowa station (69.0 S, 39.5 E). The long-term variability and trend observed in Umkehr ozone profile data is in good agreement with the station’s overpass subset of the SBUV V8.6 Merged Ozone Dataset. The long-term trend is affected by the changes in the polar vortex position and its persistence relative to the geophysical location of Syowa station. We have found a high correlation between the Equivalent Latitude (EqLat) at 850K (10 hPa or 32 km) and stratospheric ozone. The Southern Hemisphere Annular Mode (SAM) is also considered as one of the explanatory parameters in our analysis of ozone variability over Syowa. High correlation is found between stratospheric ozone and SAM during high solar activity years (HS, 1978-1982, 1988-1992, and 1998-2002). The largest variability in the Antarctic stratosphere related to the SAM signal is observed from September to December. Since the SAM and upper stratospheric ozone are both affected by planetary wave propagation, their correlation reflects their response to the same mechanism, especially during HS.In this presentation, we describe attribution of ozone variability to the proxies and discuss differences in factors that affect upper, middle and lower stratospheric ozone over Syowa.第4回極域科学シンポジウム個別セッション：[OM] 気水圏11月14日（木） 統計数理研究所 ３階セミナー室１（D305

Thermal Modification of Color in Red Alder Veneer. I. Effects of Temperature, Heating Time, and Wood Type

Red alder has become one of the most widely traded hardwood species in North America, and sliced red alder veneer is commonly applied as a decorative overlay on composite wood panels used by the furniture and cabinet industries. Red alder wood, however, acquires a mottled orange color following felling, which is undesirable when the wood is used for decorative purposes. Heating red alder wood remedies this problem to some extent, but there is still an unacceptable level of variability in the color of veneer sliced from heated veneer cants. This study examined the variation in color of red alder wood samples cut sequentially from the pith to the bark and subjected to heating under isothermal conditions. The aim was to examine whether within-tree variation in the susceptibility of red alder wood to thermal darkening can explain variation in color of veneer sliced from steamed red alder cants, and to determine the optimal thermal treatment (temperature and time) that can impart the tan color to red alder wood that industry is seeking. Results indicated that there was within-tree variation in the color of red alder samples following thermal treatment, but differences were pronounced only when wood was heated at a low temperature. Wood close to the bark tended to be redder than wood close to the pith when heated at 30°C, but such a difference was absent in wood heated at higher temperatures (50-90°C). Heating red alder wood, in vitro, at 70°C for 36 h produced wood that was evenly colored from pith to bark and matched the current industry color preference. It is suggested that the color of thermally modified red alder wood depends on the strength of reactions that produce orange/red chromophores in the wood, thermal darkening of the wood, and destruction of orange/red chromophores

The Infinity Mirror: Learning to Lead Through Action-Oriented Inquiry

This dissertation-in-practice is a reflective self-study exploring the lived experience of the current researcher as a leader of Lesson Study (LS) over 2 years. Drawing on the concepts of perspective and engagement articulated by Wenger-Trayner and Wenger- Trayner (2016) in their Learning in Landscapes of Practice conceptual framework, the study is organized around the primary critical question: How has my perspective on what it means to be a teacher leader been transformed through my engagement with LS in the context of a US community of educational practice? Working within the paradigm of first person action-oriented inquiry, the method of self-study was selected in order to describe, interpret, evaluate and thematize the researcher’s experience. This study is informed by a set of data comprising memos from an action reflection journal and artifacts from the leadership of LS, which include emails composed by the current researcher that were sent to colleagues and mentors. The description and interpretation aspects of this study provide an account of the current researcher’s practical knowledge about enacting LS for others to consider when planning actions in their own contexts, though the experience disclosed here is unique to the current investigator’s perceptual experience and cannot be generalized. The evaluation and thematization aspects of this study contribute to the discussion of the potential LS and action-oriented inquiry have in the guidance of professional learning for scholarly educational practitioners in the United States