China
Africa
Explore chapters and articles related to this topic
Avoiding Risk
Published in Kenneth L. Mossman, Radiation Risks in Perspective, 2006
The refusal of the U.S. to adopt the modern metric system continues to cause communication problems in the international arena. The U.S. is the only industrialized country in the world not officially using the modern metric system. Because of its many advantages, including easy conversion between units of the same quantity, the modern metric system has become the internationally accepted system of measurement units. The U.S. government should adopt it with the gray (Gy) as the fundamental unit of absorbed dose. The U.S. NRC has already initiated an effort to use the modern metric system. Since 1993, the agency has published new regulations, regulatory guides, and other agency documents in dual units (English system and modern metric system) to facilitate use of modern metrics by licensees.32 This is not a perfect solution, but it is a worthwhile effort to get licensees and others to use the modern metric system. By doing so, the U.S. will align itself with the rest of the world. We should think globally rather than locally about radiological health and safety.
Fundamental Concepts and Quantities
Published in Shaheen A. Dewji, Nolan E. Hertel, Advanced Radiation Protection Dosimetry, 2019
The modern metric system of measurement is the International System of Units (SI). The International Bureau of Weights and Measures (BIPM) was established in 1875 with the task of ensuring the unification of measurements via the fundamental standards and scales used for the measurement of the principal physical quantities, as well as to maintain international prototypes. The BIPM publishes an SI brochure (Bureau International des Poids et Mesures (BIPM) 2006) that describes and defines the various quantities and units used in the SI. The National Institute of Standards and Technology (NIST) is tasked with implementing the SI system in the United States, and NIST Special Publication (SP) 330 (Taylor and Thompson 2008) is the U.S. version of the BIPM SI brochure.
General Information
Published in Fiona Cobb, Structural Engineer’s Pocket Book, 2020
The most universal system of measurement is the International System of Units, referred to as SI, which is an absolute system of measurement based upon the fundamental quantities of mass, length and time, independent of where the measurements are made. This means that while mass remains constant, the unit of force (newton) will vary with location. The acceleration due to gravity on earth is 9.81 m/s2.
Backstepping control for stochastic nonlinear strict-feedback systems based on observer with incomplete measurements
Published in International Journal of Control, 2022
Lidong Wang, Xiaoping Liu, Xinze Xue, Yingxin Wei, Tong Li, Xuebo Chen
If the output measurement satisfies with a saturation level , then and If we have , and the saturation can be described as . In the scenario of data-losing or the sensors that collect the system output signal being attacked, , the received data will be discarded, and the loss data is replaced with the previous normal acquisition value. Accordingly, the data-losing function can be defined as , where , which is considered as a constant, i.e. , denotes the last normal output of the system. In this paper, it is assumed that the start and end time of the system output measurement states such as normal, saturation and data-losing are known. Thus, the is also known.
The evaluating on EEDI and fuel consumption of an inland river 800PCC integrated with solar photovoltaic system
Published in Journal of Marine Engineering & Technology, 2021
Chengqing Yuan, Pengcheng Pan, Yuwei Sun, Xinping Yan, Xujing Tang
The Differential Positioning System (DGPS) measurement system was used to conduct the sailing speed tests. To allow comparison of the actual sailing speed data with the outcomes of increased speeds, five different main engine speeds of the left and right engines were set for testing: 340, 363, 389, 413 and 428 r/min, respectively. The average speed of the one-way trip under the same working conditions is the hydrostatic speed of the ship during the tests. Making use of the data collected under the different engine speeds in calm water when the ship has an average draught of 2.72 m. The results of sailing speed tests are shown in Table 6.
The US failure to adopt the metric system: the high cost of teaching the English system
Published in International Journal of Mathematical Education in Science and Technology, 2022
Mary C. Enderson, David D. Selover
This study points out that little research has been carried out recently in the US related to the adoption of the metric system of measurement. It has been long established that geometry and measurement at the elementary and middle levels can present challenges for teachers to teach (Clements, 2003; Smith et al., 2005), but there has been very little focus on the metric system specifically. More research in this area of measurement would help provide additional evidence for the US to eliminate the English system of measurement from the elementary and middle school curricula and instruction.