A Hierarchical Cache Coherent Protocol

As the number of processors in distributed-memory multiprocessors grows, efficiently supporting a shared-memory programming model becomes difficult. We have designed the Protocol for Hierarchical Directories (PHD) to allow shared-memory support for systems containing massive numbers of processors. PHD eliminates bandwidth problems by using a scalable network, decreases hot-spots by not relying on a single point to distribute blocks, and uses a scalable amount of space for its directories. PHD provides a shared-memory model by synthesizing a global shared memory from the local memories of processors. PHD supports sequentially consistent read, write, and test- and-set operations. This thesis also introduces a method of describing locality for hierarchical protocols and employs this method in the derivation of an abstract model of the protocol behavior. An embedded model, based on the work of Johnson[ISCA19], describes the protocol behavior when mapped to a k-ary n-cube. The thesis uses these two models to study the average height in the hierarchy that operations reach, the longest path messages travel, the number of messages that operations generate, the inter-transaction issue time, and the protocol overhead for different locality parameters, degrees of multithreading, and machine sizes. We determine that multithreading is only useful for approximately two to four threads; any additional interleaving does not decrease the overall latency. For small machines and high locality applications, this limitation is due mainly to the length of the running threads. For large machines with medium to low locality, this limitation is due mainly to the protocol overhead being too large. Our study using the embedded model shows that in situations where the run length between references to shared memory is at least an order of magnitude longer than the time to process a single state transition in the protocol, applications exhibit good performance. If separate controllers for processing protocol requests are included, the protocol scales to 32k processor machines as long as the application exhibits hierarchical locality: at least 22% of the global references must be able to be satisfied locally; at most 35% of the global references are allowed to reach the top level of the hierarchy

The IUSM Scholarly Concentrations Program: Strategic Collaborative Education Across Schools and Departments

Presented as a poster at 2020 IUSM Education Day.A changing healthcare landscape calls for innovation and expansion of expertise in medical education. How does a medical school better prepare medical students to thrive in a changing profession? Through its Scholarly Concentrations Program, Indiana University School of Medicine is collaborating with non-physician experts from schools with expertise in topics that are medically relevant and of interest to medical students. Scholarly Concentrations are longitudinal experiences that enhance the medical education program through coursework and scholarly work. In addition to enhancing students’ education, it offers the opportunity to enhance campus reputation and develop research focus for students and faculty. Partnerships were created in both directions. IU School of Medicine sought out schools and departments with unique expertise on different medical campuses. Schools and departments also approached IU School of Medicine about its Scholarly Concentrations program as momentum built. These partnerships are creating mutual benefits for IUSM, partners, faculty and students. Benefits for partner organizations include mentoring opportunities, reputational enhancement, having an impact on healthcare system, and pathways to certificates and advanced degrees. For IUSM and its students, the partnerships enhance professional development through Scholarly Concentrations in areas of clinical, teaching, research, advocacy and administration

Scholarly Concentrations Program: A PRIME Approach to Addressing Care for the Medically Underserved and Vulnerable Populations

Examine how well the structure of the Scholarly Concentrations Program and content of each concentration relates to the goals of the federal Health Resources and Services Administration grant received to create more interest and prepare more medical school graduates to care for medically underserved and vulnerable populations. The grant funds the Primary Care Reaffirmation for Indiana Medical Education, or PRIME. project. A review of how concentrations align with the grant was conducted by reviewing program, concentration and course learning objectives and mapping to the grant objectives. Numerous concentrations were found to be an excellent fit, creating a PRIME opportunity to enhance the SC Program and move the needle on the grant objectives

Scholarly Concentrations: A Novel Platform for Delivery of Health Systems Science Exposure and Highlight Unique Learning Environments Across the Nine Campuses of Indiana University School of Medicine

Presented as a Poster at 2020 IUSM Education Day.Rapidly evolving challenges in health care mandate changes in the way health care professionals are educated. How do we integrate the need for new and different content into the medical school curriculum? One area of particular focus is called Health Systems Science. Health Systems Science is being called the 3rd leg of modern medical education to complement the foundational and clinical sciences curricula. IU School of Medicine is integrating Health Systems Science content into Scholarly Concentrations. Scholarly Concentrations is a program offering students longitudinal educational enhancement through coursework and scholarly work

Medical School Without Walls: 50 Years of Regional Campuses at Indiana University School of Medicine

The history of Indiana University School of Medicine (IUSM) dates to 1871, when Indiana Medical College entered into an affiliation with Indiana University in Bloomington to offer medical education. In 1971, the Indiana General Assembly passed a bill to create and fund a distributed model for medical education for which IUSM was responsible, an innovative approach to implementing a statewide medical education program. IUSM became one of the first U.S. medical schools to implement what is today known as a regional medical campus model. This regional medical campus system has permitted IUSM to expand enrollment based on national and local concerns about physician shortages, increase access to care locally, support expansion of graduate medical education, and provide opportunities for research and scholarship by faculty and students statewide. This effort was made possible by partnerships with other universities and health care systems across the state and the support of local community and state leaders. The model is a forward-thinking and cost-effective way to educate physicians for service in the state of Indiana and is applicable to others. This article highlights milestones in IUSM’s 50-year history of regional medical education, describes the development of the regional medical campus model, recognizes significant achievements over the years, shares lessons learned, and discusses considerations for the future of medical education

Bigtable: A Distributed Storage System for Structured Data

BigTable是一个分布式存储系统，它可以支持扩展到很大尺寸的数据：PB级别的数据，包含几千个商业服务器。Google的许多项目都存储在BigTable中，包括WEB索引、Google Earth 和Google Finance。这些应用对BigTable提出了截然不同的需求，无论是从数据量（从URL到网页到卫星图像）而言，还是从延迟需求（从后端批量处理到实时数据服务）而言。尽管这些不同的需求，BigTable已经为所有的Google产品提供了一个灵活的、高性能的解决方案。本文中，我们描述了BigTable提供的简单数据模型，它允许客户端对数据部署和格式进行动态控制，我们描述了BigTable的设计和实施

Labeling Preschoolers as Learning Disabled: A Cautionary Position

The purpose of this article is to explore the issues concerning the adaptation of school-based service delivery concepts for use in early childhood special education programs. The use of categorical labels for determining eligibility for preschool children is not required by law—and may be detrimental. The following concerns are discussed: (a) definitional issues in learning disabilities versus low achievement, (b) the dangers of labeling and low expectation sets, (c) repeated failure to demonstrate movement through a continuum of services (particularly to least restrictive environments), and (d) the efficacy of early intervention and school-based special services for those with mild or suspected developmental disabilities. Research is reviewed concerning definitional and assessment issues utilizing learning disabilities as a construct. Alternatives for describing the characteristics of young children who are significantly at risk or developmentally delayed are provided.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

PHD--a hierarchical cache coherent protocol

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1992.Includes bibliographical references (p. 155-157).by Deborah A. Wallach.M.S