1,784 research outputs found
Adaptive algorithms for active sound-profiling
No full textThree novel adaptive algorithms are proposed for use in active sound-profiling, all based on the filtered-X least mean square (FXLMS) approach. The algorithms are analyzed for their stability properties and control effort load, and are compared with the currently used adaptive noise equalizer least mean square (ANE-LMS) algorithm. It is found that the most suitable algorithm, both in simulations and experimentally, is the phase scheduled command FXLMS (PSC-FXLMS), which possesses both low control effort and good stability in the face of plant model misestimation, especially when using an automatic phase command law
Letter to Elizabeth Rees about Distant Family
No full textLetter addressed to Elizabeth Rees, but because the last pages of this letter were lost there is no way of telling who it is from. The letter states that the author’s nephew is recovering from the swelling of his limbs and is expected to be okay. The author’s cousin Thomas will be visiting soon along with the rest of his family. Then the author continues to speak of the different marriages that have been occurring locally. This is one item from the Rees Family Correspondence Collection, which includes many letters between family members in Oregon and Ohio
Letter to a Brother of the Rees Family about Politics
No full textLetter addressed to a brother of the Rees family, but neither the author of the letter nor who the letter is to be mentioned. The letter talks about local gossip in Butteville. Then the letter cuts off and switches from March to December and talks about the Presidential candidates for 1876. It was a close race between Samuel J. Tilden and Rutherford B. Hayes, with Hayes winning the election. The author of this letter strong supports the Federalist views while talking about politics during this time. This is one item from the Rees Family Correspondence Collection, which includes many letters between family members in Oregon and Ohio
Horizontal and compact ground heat exchangers
No full textThis chapter describes horizontal ground heat exchanger (GHE) technology that is commonly applied to residential buildings and small non-residential buildings along with examples of innovative compact GHE designs. The essential physical properties and processes that are involved in shallow GHE behaviour are described - some of which are arguably more complex than have to be considered in other forms of GHE. Sources of design information and associated uncertainties are discussed along some of the developments in design models and methodologies. Two recently developed models that can be used to simulate GHE behaviour and capture the geometric complexities of certain forms of horizontal GHE are described in detail towards the end of this chapter
An introduction to ground-source heat pump technology
No full textGround-source heat pumps (GSHPs, or geothermal heat pumps) have great appeal in offering levels of efficiency for building heat and cooling that are - both theoretically and practically - higher than other technologies. This chapter introduces the technology and reviews its historical development and current state of exploitation around the world. Current challenges and prospects are discussed
A review of active noise and vibration control in road vehicles
No full textActive control works by destructive interference between the original sound or vibration field in the vehicle and that generated by a controllable, secondary, source. Physical limitations generally confine its usefulness to low frequencies and so that it complements conventional passive control methods. The development of powerful processors at an affordable cost and the increasing trend towards integration in vehicles has allowed the commercial implementation of active control systems by several manufacturers, mainly for the reduction of low frequency engine noise. As vehicles become lighter to achieve fuel efficiency targets, it is expected that active control will play an important part in maintaining an acceptable NVH environment, in terms of sound quality as well as overall level
On the future: prospects for humanity/ Martin Rees, with a new preface by the author.
No full textDescription based upon print version of record.Includes bibliographical references and index.A provocative and inspiring look at the future of humanity and science from world-renowned scientist and bestselling author Martin ReesHumanity has reached a critical moment. Our world is unsettled and rapidly changing, and we face existential risks over the next century. Various outcomes--good and bad--are possible. Yet our approach to the future is characterized by short-term thinking, polarizing debates, alarmist rhetoric, and pessimism. In this short, exhilarating book, renowned scientist and bestselling author Martin Rees argues that humanity's prospects depend on our taking a very different approach to planning for tomorrow.The future of humanity is bound to the future of science and hinges on how successfully we harness technological advances to address our challenges. If we are to use science to solve our problems while avoiding its dystopian risks, we must think rationally, globally, collectively, and optimistically about the long term. Advances in biotechnology, cybertechnology, robotics, and artificial intelligence--if pursued and applied wisely--could empower us to boost the developing and developed world and overcome the threats humanity faces on Earth, from climate change to nuclear war. At the same time, further advances in space science will allow humans to explore the solar system and beyond with robots and AI. But there is no "Plan B" for Earth--no viable alternative within reach if we do not care for our home planet.Rich with fascinating insights into cutting-edge science and technology, this accessible book will captivate anyone who wants to understand the critical issues that will define the future of humanity on Earth and beyond.Cover -- Contents -- Preface to the Paperback Edition -- Introduction -- 1. Deep in the Anthropocene -- 1.1. Perils and Prospects -- 1.2. Nuclear Threats -- 1.3. Eco-Threats and Tipping Points -- 1.4. Staying within Planetary Boundaries -- 1.5. Climate Change -- 1.6. Clean Energy-and a 'Plan B'? -- 2. Humanity's Future on Earth -- 2.1. Biotech -- 2.2. Cybertechnology, Robotics, and AI -- 2.3. What about Our Jobs? -- 2.4. Human-Level Intelligence? -- 2.5. Truly Existential Risks? -- 3. Humanity in a Cosmic Perspective -- 3.1. The Earth in a Cosmic Context -- 3.2. Beyond Our Solar System -- 3.3. Spaceflight-Manned and Unmanned -- 3.4. Towards a Post-Human Era? -- 3.5. Alien Intelligence? -- 4. The Limits and Future of Science -- 4.1. From the Simple to the Complex -- 4.2. Making Sense of Our Complex World -- 4.3. How Far Does Physical Reality Extend? -- 4.4. Will Science 'Hit the Buffers'? -- 4.5. What about God? -- 5. Conclusions -- 5.1. Doing Science -- 5.2. Science in Society -- 5.3. Shared Hopes and Fears.1 online resource (281 p.
Numerical investigation of transient buoyant flow in a room with a displacement ventilation and chilled ceiling system
No full textThis paper presents the major findings of the PhD work of Rees, who wrote the paper and is the lead author
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