Hard copies of monographs and back issues (Volume 1, Issue 1 through Volume 8, Issue 3) are available for purchase. Prices and ordering information can be found at http://www.uchsc.edu/ai/ncaianmhr/pdf_files/Journal_Order_Form.pdf. This article describes the collective experience of a multidisciplinary network of researchers, practitioners, and program evaluators who support appropriate research and evaluation methods in working with Native peoples. Our experience underlines the critical importance of culture in understanding and conducting research with the diverse populations of American Indians and Alaska Natives, and documents the need for community-based, collaborative, participatory action research. We discuss the major findings of the first American Indian Research and Program Evaluation Methodology national symposium, and articulate a set of 20 guiding principles for conducting research and program evaluation.Keywords: American Indians and Alaska Natives, Community-based Participatory Research, Participatory Action Research, CultureThis article presents a call for systematic change in how research and program evaluation are conducted in Indian Country. 3 The authors do not intend to offer innovative research and evaluation methods; rather, we draw upon our collective experience, much of it based on working with individuals who have chronic illnesses and disabilities, to offer consolidated documentation for requiring that research and program evaluation in Indian Country be participatory. Further, we offer 20 guiding American Indian and Alaska Native Mental Health Research Copyright: Centers for American Indian and Alaska Native Health Colorado School of Public Health/University of Colorado Anschutz Medical Campus (www.ucdenver.edu/caianh) 2 VOLUME 12, NUMBER 1 principles, derived through the First Symposium of the Work Group on American Indian Research and Program Evaluation Methodology (AIRPEM), that we believe are basic to culturally respectful research and program evaluation. While the purposes of research and program evaluation activities often differ, the methods employed may be quite similar; for this reason, reference to research throughout this article can generally be assumed to apply to program evaluation as well.The special circumstances of American Indians and Alaska Natives (AI/ANs) affect research, program evaluation, and service delivery in Indian Country. In this regard, two fundamental considerations merit particular mention: tribal sovereignty and diversity. Tribal sovereignty means that AI/AN communities are sovereign political entities, each with its own form of governance, culture, and history. Second, AI/ANs are often mistakenly viewed as a single ethnic minority population (also referred to as the homogeneity assumption). In fact, over 560 Native nations and tribal entities exist in this country, constituting distinct cultural as well as political groups. In Alaska, for instance, there are at least four different cultural groups often referred to as Alaska Natives: Eskimos, Ale...

This paper describes the design and modelling of a new variable stiffness actuator (CompAct-VSA). The principle of operation of CompAct-VSA is based on a lever arm mechanism with a continuously regulated pivot point. The proposed concept allows for the development of an actuation unit with a wide range of stiffness and a fast stiffness regulation response. The implementation of the actuator makes use of a cam shaped lever arm with a variable pivot axis actuated by a rack and pinion transmission system. This realization results in a highly integrated and modular assembly. Size and weight are indeed an open issue in the VSAs design, which ultimately limit their implementation in multi-dof robotic systems. The paper introduces the mechanics, the principle of operation and the model of the actuator. Preliminary results are presented to demonstrate the fast stiffness regulation response and the wide range of stiffness achieved by the proposed CompAct-VSA design.

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A b s t r a c t Multilevel Fiduccia-Mattheyses (MLFM) hypergraph partitioning [3, 22, 241 is a fundamental optimization in VLSI CAD physical design. The leading implementation, hMetis [23], has since 1997 proved itself substantially superior in both runtime and solution quality to even very recent works (e.g., [13,17, 251). In this work, we present two sets of results: (i) new techniques for flat FM-based hypergraph partitioning (which is the core of multilevel implementations), and (ii) a new multilevel implementation that offers leadingedge performance.Our new techniques for flat partitioning confirm the conjecture from [lo], suggesting that specialized partitioning heuristics may be able t o actively exploit fixed nodes in partitioning instances arising in the driving top-down placement context. Our FM variant is competitive with traditional FM on instances without terminals [l] and considerably superior on instances with fixed nodes (i.e., arising during top-down placement [SI).Our multilevel FM variant avoids several complex heuristics and non-trivial tunings that often lead to complex implementations; it achieves trade-offs between solution quality and run time that are comparable or better than those achieved by hMetis-1.5.3 (the latest available version). Following [6], we attempt to provide algorithm descriptions that are as detailed and unambiguous as possible, to allow replicability and speed improvements in future research. I n t r o d u c t i o nHypergraph partitioning is important to many application domains including data mining, job scheduling, hardwaresoftware partitioning, VLSI circuit layout and numerical linear algebra. Balanced partitioning typically represents the "divide" step of "divide-and-conquer" algorithms and seeks to assign the nodes of a [hyperlgraph into groups of approximately equal total weight (i.e., satisfying balance constraints) while minimizing the number of [hyperledges that are cut (i.e., adjacent t o nodes in different groups).In some applications (notably in top-down VLSI circuit placement), problem instances have fixed nodes. These instances are easier than the "free hypergraph instances that have dominated VLSI partitioning research in the past [lo]. Therefore, in addition to the ISPD-98 "free hypergraph" suite released by IBM [l], similar instances with fixed nodes were released at ISPD-99 [8].[lo] suggested that specialized partitioning heuristics may be able to actively exploit fixed nodes, in contrast t o common FM variants which simply tolerate fixed nodes. In our first set of contributions we demonstrate such a technique with the additional property of not incurring significant overhead when there are no terminals (cf.[lo]).Our second set of contributions is in multilevel partitioning. This algorithm framework entails a clustering of the original hypergraph so that clusters can be partitioned, after which the clustered partitioning solution is refined in many steps [22, 241. The technique is used, e.g., by the leading hypergraph partitioning tool for large hyper...

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