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For five years, OpenPiton has provided hardware designs, build and verification scripts, and other infrastructure to enable efficient, detailed research into manycores and systems-on-chip. It enables open-source hardware development through its open design and support of a plethora of open simulators and CAD tools. OpenPiton was first designed to perform cutting-edge computer architecture research at Princeton University and opening it up to the public has led to thousands of downloads and numerous academic publications spanning many subfields within computing. In this article, we share some of the lessons learned during the development of OpenPiton, provide examples of how OpenPiton has been used to efficiently test novel research ideas, and discuss how OpenPiton has evolved due to its open development and feedback from the open-source community.

As device technology advances into the sub-10nm era, the design costs of Field Programmable Gate Arrays (FPGAs) built out of fully-custom, hand-layout blocks have increased dramatically. At the same time, Embedded FPGAs (eFPGAs) are picking up steam in heterogeneous system-on-chip designs, in which case supporting customizable FPGA architectures and reducing design costs are more crucial than squeezing the last bit of performance out of the transistors. To reduce the cost and complexity of FPGA designs, prior works have proposed to build FPGAs using Electronic Design Automation (EDA) tools and standard-cell libraries. Though functionally viable, this approach faces two challenges: 1) An accurate timing model is crucial for FPGA implementation tools to produce correct and optimal results. However, post-layout Static Timing Analysis (STA) with EDA tools is error-prone on FPGAs, because the typical FPGA routing graphs contain many cycles at design time. 2) Conventional FPGA design relies heavily on iterative/empirical improvements to achieve optimal floorplanning and time-budgeting. Without such insights, blocks may be shaped and constrained sub-optimally. This work addresses the first challenge by proposing an algorithm to derive cycle-free sub-graphs. A cycle-free subgraph is achieved by logically ranking the routing tracks and selectively removing some switch block connections. Each subgraph enables accurate, per-switch, post-layout STA, and the union of multiple sub-graphs covers all the timing arcs of the FPGA. Furthermore, our proposed approach addresses the second challenge by enabling the creation of intrinsically cycle-free FPGAs that facilitate a flat multi-block or full-chip design flow. By blending the blocks, the EDA tools can exploit more optimization opportunities and automatically adapt to heterogeneous blocks. Our experiments show that the routability of cycle-free routing graphs is comparable to conventional FPGA routing graphs, and the Quality of Results (QoR) of the FPGA layout is superior to the result of previous approaches.

Organic thin-film transistors (OTFTs) are drawing increasing attention due to their unique advantages of mechanical flexibility, low-cost fabrication, and biodegradability, enabling diverse applications that were not achievable using traditional inorganic transistors. With a growing number of complex applications being proposed, the need for expediting the design process and ensuring the yield of large-scale designs with organic technology increases. A complete digital standard cell library plays a crucial role in integrating the emerging organic technology into existing computer-aided-design (CAD) flows. In this paper, we present the design, fabrication, and characterization of a standard cell library based on bottom gate, top contact pentacene OTFTs. We also propose a commercial tool compatible, RTL-to-GDS flow along with a new organic process design kit (PDK) developed based on our process. To the best of our knowledge, this is the first open-source organic standard cell library, enabling the community to explore this emerging technology.

Organic thin-film transistors (OTFTs) are a promising technology for large-area electronics; choosing an appropriate circuit style is critical to enhancing OTFT circuit functionality and reliability. Here, we design and evaluate different types of static and dynamic logic based on complementary and p-type only technology styles, benchmarking their performance under equivalent processing and testing conditions. We find that differences in off characteristics between n-type and p-type OTFTs to be the primary factor for the choice of logic style. For complementary technology, we conclude that static logic is preferred over dynamic logic considering limited n-type transistor off characteristics, integration density, and delay. In the case of p-type transistors, pre-discharge dynamic logic is preferred over static logic, primarily due to the static power efficiency from good p-type transistor off characteristics. We expect this evaluation to be helpful for assisting design style decisions as these technologies continue to mature and develop.

Conventional microstrip unequal Wilkinson power divider is difficult to be realized when the power ratio is not small because high impedance transmission line is usually used. Although the previous unequal divider in 2012 can relax the high impedance line usage, the structure results in low impedance line issue. Therefore, this study proposed a modified unequal Wilkinson power divider using T-shaped transformers can avoid high and low impedance lines simultaneously.

Organic thin-film transistors (OTFTs) have attracted increased attention because of the possibility to produce environmentally friendly, low-cost, lightweight, flexible, and even biodegradable devices. With an increasing number of complex applications being proposed for organic and biodegradable semiconductors, the need for computation horsepower also rises. However, due to the process characteristic differences, direct adaptation of silicon-based circuit designs and traditional computer architecture wisdom is not applicable. In this paper, we analyze the architectural tradeoffs for processor cores made with an organic semiconductor process. We built an OTFT simulation framework based on experimental pentacene OTFTs. This framework includes an organic standard cell library and can be generalized to other organic semiconductors. Our results demonstrate that, compared to modern silicon, organic semiconductors favor building deeper pipelines and wider superscalar designs. To the best of our knowledge, this is the first work to explore the architectural differences between silicon and organic technology processes. CCS CONCEPTS • Hardware → Emerging architectures; Carbon based electronics; Impact on the environment; Standard cell libraries; Modeling and parameter extraction; Emerging simulation; • Social and professional topics → Sustainability

Tai chi has been increasingly applied in osteoporosis patients. However, systematic reviews of the efficacy of this practice have been few and of limited scope.This study reviews previous experimental research work using tai chi as an intervention in postmenopausal women with osteoporosis and to appraise the reported research designs used, tai chi methods used, and outcomes.A systematic review method was used to search 14 databases for articles published between January 1980 and July 2013. Searched keywords included: "tai chi," "osteoporosis," and "postmenopausal women". The 2,458 articles initially identified were reduced to 4 valid articles based on considerations of criteria and repeatability. The 4 valid articles used either a randomized clinical trial (RCT) or a controlled clinical trial (CCT). They were further analyzed and synthesized in terms of common variables such as balance, muscle strength, and quality of life.Three of the 4 studies identified significant pretest / posttest differences in physiological aspects of quality of life in participants but did not obtain consistent results in terms of the psychological aspects. While reports identified a significant and positive tai chi effect on balance, they all used different measurements to do so. Only one of the four studies identified significant improvement in muscle strength. Therefore, this review could not identify clear support for the effectiveness of tai chi on balance or muscle strength.This review did not definitively support the positive effects of tai chi on balance, muscle strength, and quality of life in postmenopausal women with osteoporosis. The designs used in the tai chi interventions may be referenced for future studies. We suggest that future studies use data triangulation rather than a single-item tool to validate the research in order to cross-verify the same information. This may strengthen the research and increase the credibility and the validity of related findings.運用太極拳於停經後骨質疏鬆婦女之成效探討—系統性文獻回顧太極拳是近年來常用於骨質疏鬆症患者的運動介入方案，但目前仍缺乏以停經後骨質疏鬆婦女為族群之系統性文獻探討。本文是回顧以太極拳為介入措施於停經後骨質疏鬆婦女之臨床實驗性研究，對於研究方法、太極拳法及其成效品質做評價，期以利太極拳運動訓練的推廣。以系統文獻回顧法搜尋1980年1月～2013年7月年間發表於14個電子資料庫，關鍵字含太極拳、骨質疏鬆、停經後婦女等字彙群組，搜尋共2,458篇文獻，排除重複性及未符合篩選標準文獻，最後剩下4篇等級較高的隨機控制實驗性研究，並針對文中相同的變項（平衡感、肌力、生活品質）進行整理與分析。4篇研究中，有3篇太極拳對於停經後骨質疏鬆婦女生活品質之生理層面項目較有顯著性成效，但心理成效研究結果較不一致，在平衡感評估，雖使用不同測量工具但都有其成效。肌力只有一篇有顯著性成效，故較難整體評價太極拳對於平衡感與肌力之影響。太極拳對停經後骨質疏鬆婦女於生活品質、平衡感與肌力之影響仍待商確，但其研究操作手法仍可提供未來介入之參考。另建議使用多元化工具測量同一項量以提供更完善的成效評價，增加研究的信效度。

Background/Purpose: We know of no validated Taiwanese-language instrument to measure a utility of the patient's health. Our aim was to evaluate the reliability and validity of a Taiwanese version of the EuroQol instrument (EQ-5D) in a Taiwanese population. Methods: Questionnaires containing the Taiwanese versions of the EQ-5D and the Short-Form 12 Health Survey (SF-12) were sent to 12,923 people in Taiwan in December 2002. Concurrent validity of the EQ-5D was analyzed by assuming that subjects with problems in any EQ-5D dimensions had decreased SF-12 scores. Discriminant validity of the EQ-5D was analyzed by assuming that subjects with the following characteristics had lowered EQ-5D indexes and scores on the EQ-5D visual analog scale (VAS): more chronic diseases than others, serious illness, more hospitalizations in the past year than others, poor general health, and more outpatient visits than others. Test-retest reliability was analyzed in a subgroup of respondents who were evaluated twice within a month by using the intraclass correlation coefficient and the κ method. Results: The general survey response rate was 12.7% (1644 of 12,923). SF-12 scores were lower in subjects reporting problems on EQ-5D dimensions than in others without such problems (p＜0.01). Subjects with more health problems than others had lower EQ-5D indexes and VAS scores (p＜0.01). The physical dimension of the EQ-5D was more strongly correlated with the SF-12 Physical Component Summary than with the Mental Component Summary; this finding satisfied the a priori hypothesis. For test-retest reliability of items on the EQ-5D, κ values ranged from 0.49 to 1 (p＜0.001). Conclusion: The Taiwanese EQ-5D instrument appears to be a moderately valid and reliable tool for measuring the health status of the general population in Taiwan.

Arylpiperazine derivatives were synthesized and investigated in this study. Two animal models, including an intraocular pressure (IOP) recovery method and an alpha-chymotrypsin-induced glaucoma model, were used to determine the ocular pharmacological effects of the arylpiperazine derivatives. In the IOP recovery method, New Zealand rabbits with normal IOP were instilled with 50 microliters of 0.5% eye drops, then 10% sodium chloride solution was infused through the ear marginal vein. The relative percent of IOPs were calculated, then delta IOPt% was obtained from the difference of IOPt% between the treated and controlled eye. In the alpha-chymotrypsin-induced glaucoma model, the induced glaucoma rabbits were topically instilled with 0.5% arylpiperazines onto the eyes, and then the IOP changes were calculated to evaluate the effect of eye drops. Our results showed that in the IOP recovery method, BG31 and YCT2-2 demonstrated a very significant effect for reducing IOP; delta IOPt% were -27.6 and -25.5 for BG31 and YCT2-2, respectively. Two other compounds, C219 and C220 also lowered IOP, but the effects were less significant. In alpha-chymotrypsin-induced glaucoma, the maximum effect of YCT2-2 on the IOP was found at 5 hrs. The delta IOP and delta delta IOP were -12.5 +/- 1.7 and -5.8 +/- 1.1 mmHg (p < 0.01), respectively. For BG-31 and C220, there existed a trend to increase IOP with time. In the study, we found that YCT2-2 with higher solubility in the acidic condition was correlated to the significant IOP lowering effect.

By the signless Laplacian of a (simple) graph G we mean the matrix Q ( G ) = D ( G ) + A ( G ) , where A ( G ) , D ( G ) denote respectively the adjacency matrix and the diagonal matrix of vertex degrees of G . It is known that connected graphs G that maximize the signless Laplacian spectral radius ρ ( Q ( G ) ) over all connected graphs with given numbers of vertices and edges are (degree) maximal. For a maximal graph G with n vertices and r distinct vertex degrees δ r > δ r - 1 > ⋯ > δ 1 , it is proved that ρ ( Q ( G ) ) ρ ( Q ( H ) ) for some maximal graph H with n + 1 (respectively, n ) vertices and the same number of edges as G if either G has precisely two dominating vertices or there exists an integer i , 2 ⩽ i ⩽ r 2 respectively, if there exist positive integers i , l with l + 2 ⩽ i ⩽ r 2 such that δ i + δ r + 1 - i ⩽ n + 1 (respectively, δ i + δ r + 1 - i ⩽ δ l + δ r - l + 1 ). Graphs that maximize ρ ( Q ( G ) ) over the class of graphs with m edges and m - k vertices, for k = 0 , 1 , 2 , 3 , are completely determined.