Method for measuring the low-frequency sound power from a complex sound source based on sound-field correction in a non-anechoic tank

Similar to air reverberation chambers, non-anechoic water tanks are important acoustic measurement devices that can be used to measure the sound power radiated from complex underwater sound sources using diffusion field theory. However,the problem of the poor applicability of low-frequency measurements in these tanks has not yet been solved. Therefore,we propose a low-frequency acoustic measurement method based on sound-field correction(SFC) in an enclosed space that effectively solves the problem of measuring the sound power from complex sound sources below the Schroeder cutoff frequency in a non-anechoic tank. Using normal mode theory, the transfer relationship between the mean-square sound pressure in an underwater enclosed space and the free-field sound power of the sound source is established, and this is regarded as a correction term for the sound field between this enclosed space and the free field. This correction term can be obtained based on previous measurements of a known sound source. This term can then be used to correct the mean-square sound pressure excited by any sound source to be tested in this enclosed space and equivalently obtain its free-field sound power. Experiments were carried out in a non-anechoic water tank(9.0 m × 3.1 m × 1.7 m) to confirm the validity of the SFC method. Through measurements with a spherical sound source(whose free-field radiation characteristics are known),the correction term of the sound field between this water tank and the free field was obtained. On this basis, the sound power radiated from a cylindrical shell model under the action of mechanical excitation was measured. The measurement results were found to have a maximum deviation of 2.9 d B from the free-field results. These results show that the SFC method has good applicability in the frequency band above the first-order resonant frequency in a non-anechoic tank. This greatly expands the potential low-frequency applications of non-anechoic tanks.

Approach to the Geopolitical Influences of Great Powers in Southeast Asia: Case Studies of China and the US

A quantitative approach to the national geopolitical influence is helpful to provide a reference for national sustainable development on the international stage, based on describing national diplomatic capacity and overseas influence. Herein, this study proposes a complex geopolitical influence model, considering the affected nations' response. The geopolitical influences of great power in the affected nation are correlated with overall strength, the acceptance degree of the affected nation to the great power and the distance between both sides. Then, the geopolitical influences of China and the US in Southeast Asia countries are empirically analyzed from 2005 to 2015. The geopolitical influence of China in Southeast Asia has been largely growing for the past decades, accompanying with a constant trend of the US' effects. It is believed that China and the US can coexist peacefully in Southeast Asia to promote the regional development, and jointly create an open, inclusive and balanced regional cooperation architecture that benefits all nations in this region and great powers, through mutual political trust and economic beneficial cooperation. This study may contribute to advancing the policy debate and determining the optimal cooperation in pledging commitment to a new and sustainable model of great power relationship among the various regional geopolitical options.

Shifting Great Power Relations: Toward Consolidation of US Hegemony

The series of unilateral foreign policies taken by US President Donald Trump has worsened relations between the US and other powers including China, Russia, the EU and Japan, prompting their officials to turn to seeking bilateral arrangements when need arises. Though among these countries there is willingness to cooperate, the US seeks to consolidate hegemony. The US focus is to contain China and sanction Russia in economic and trade fields. In geopolitics and security, the EU and Japan are heavily dependent on the US and follow the US lead.

COMPLEX POWER OF HERMITE OPERATOR

In this paper the authors define complex power of Hermite operator and give some applications in Riemann Zeta function.

Realignment of Great Power Relations

Wang: Speaking of Sino-U. S. relations, actually it touches upon great power relationship. The current Iraqi crisis became a focus in UN. There is a clear demarcation line between those countries supporting a war and those countries in favor of weapons inspections within

An Analysis of the Great Power Strategy of India's Modi Government

Over the past two years, India's Modi government has demonstrated the following features: focusing on the goals of becoming a great power and shaping India's South Asian dominance, expanding the scope of diplomatic strategy, emphasizing the role of soft power and focusing on self-development as well as external environment. Modi's great power strategy is deeply influenced by the Indian realistic international political outlook and, to a certain extent, reflects the governing philosophy of the Bharatiya Janata Party. The great power strategy is Modi's governing foundation and governing style, embedding Modi distinctive personal style. Under the influence of the great power strategy, China and India have increased their economic cooperation scope, widening the forms of public diplomacy, with an obvious geopolitical collision; India is taking more measures to check China.

An Analytical Model of the Power Law Distributions in the Complex Network

It is known that complex networks in nature exhibit some significant statistical features. We notice power law distributions which frequently emerge with respect to network structures of various quantities. One example is the scale-freeness which is described by the degree distribution in the power law shape. In this paper, within an analytical approach, we investigate the analytical conditions under which the distribution is reduced to the power law. We show that power law distributions are obtained without introducing conditions specific to each system or variable. Conversely, if we demand no special condition to a distribution, it is imposed to follow the power law. This result explains the universality and the ubiquitous presence of the power law distributions in complex networks.

The Current Situation and Characteristics of the Great Power Mentality of China’s Netizens

The Great Power Mentality possessed by the citizens is an important part of the country’s soft power and a necessary condition for China’s rise.Based on the operational measurement of the Great Power Mentality,this paper uses the data of the 2015"Public Social Awareness Survey"as a support to examine the current status of the Chinese people's Great Power Mentality and the characteristics of the Great Power Mentality in different groups.The main research conclusions are as follows:First,the Great Power Mentality can be specifically operated into three types:self-confidence,normal mentality,and responsibility mentality;second,overall,among the three Great Power Mentality of the public,the self-confidence has the highest score(3.93),the normal mentality is second(3.32),and the responsibility mentality is the lowest(2.67);third,whether it is self-confidence,normal mentality,or responsibility mentality,the ideological position has a significant impact on people’s Great Power Mentality.The"Left"people’s Great Power Mentality scores higher.

Discussion on the Application of Complex Power Network to Software Engineering

Along with the further development of science and technology, computer hardware and the Intemet are in a rapid development, and information technology has been widely used in all fields so that complex problems are simply solved. Because of the needs for the development, software starts to mutually integrate with complex power network, making the scale of software increase greatly. Such a growing trend of software promotes soft-ware development to go beyond a general understanding and control and thus a complex system is formed. It is necessary to strengthen the research of complex network theory, and this is a new way to help people study the complexity of software systems. In this paper, the development course of complex dynamic network is introduced simply and the use of complex power network in the software engineering is summarized. Hopefully, this paper can help the crossover study of complex power network and software engineering in the future.

The New Trend of India's Rising as a Great Power

Since Modi took office as Indian prime minister in 2014,India has quickened its pace toward great power status.Although the Indian government did not issue relevant documents and did not systematically give official statements,from the perspective of Modi’s domestic and foreign policies the outline of its strategy of rising as a great power

An In-Depth Study of Complex Power System Dynamic Behavior Characteristics for Chinese UHV Power Grid Security

In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.

NEW METHOD TO ESTIMATE SCALING EXPONENTS OF POWER-LAW DEGREE DISTRIBUTION AND HIERARCHICAL CLUSTERING FUNCTION FOR COMPLEX NETWORKS

A new method and corresponding numerical procedure are introduced to estimate scaling exponents of power-law degree distribution and hierarchical clustering function for complex networks. This method can overcome the biased and inaccurate faults of graphical linear fitting methods commonly used in current network research. Furthermore, it is verified to have higher goodness-of-fit than graphical methods by comparing the KS （Kolmogorov-Smirnov） test statistics for 10 CNN （Connecting Nearest-Neighbor） networks.

Topographic Map Analysis of Laramie Range Bedrock-Walled Canyon Complex and the Goshen Hole Escarpment-Surrounded Basin, Albany and Platte Counties, Southeast Wyoming, USA

The Laramie River after flowing in a north direction through southeast Wyoming’s Laramie Basin abruptly turns in an east direction to flow across the north-to-south oriented Laramie Range in a bedrock-walled canyon and eventually reaches the lower elevation Great Plains and southeast-oriented North Platte River. The North Laramie River, Bluegrass Creek, and North Sybille/Sybille Creek also flow from the Laramie Basin in separate bedrock-walled valleys into the Laramie Range before eventually joining the Laramie River. Bedrock-walled through valleys link the various Laramie Range stream and river crossing valleys and detailed topographic maps were used to determine how this anastomosing bedrock-walled canyon complex and the large escarpment-surrounded Goshen Hole basin (located just to the east of the anastomosing canyon complex) originated. Map evidence shows multiple streams of water must have diverged in the Laramie Basin from the north-oriented Laramie River to enter the Laramie Range before converging in or east of the Laramie Range and also shows how present day through valleys enabled diverging and converging streams of water to cross the Laramie Range. The anastomosing bedrock-walled valley complex studied here extends from north of the North Laramie River valley to south of the North Sybille/Sybille Creek valley. Large volumes of water flowing from the Laramie Basin to the Great Plains are interpreted to have eroded the anastomosing canyon complex and the “downstream” Goshen Hole escarpment-surrounded basin. Headward erosion of the north-oriented Sybille and Chugwater Creek valleys across large sheets of east-oriented water are interpreted to have left the Goshen Hole escarpment-surrounded basin as a large abandoned headcut. A water source was not determined, although a continental ice sheet that deeply eroded and warped the North American continent is considered to be a possible source.

Power Balance of Multi-Harmonic Components in Nonlinear Network

The main harmonic components in nonlinear differential equations can be solved by using the harmonic balance principle. The nonlinear coupling relation among various harmonics can be found by balance theorem of frequency domain. The superhet receiver circuits which are described by nonlinear differential equation of comprising even degree terms include three main harmonic components: the difference frequency and two signal frequencies. Based on the nonlinear coupling relation, taking superhet circuit as an example, this paper demonstrates that the every one of three main harmonics in networks must individually observe conservation of complex power. The power of difference frequency is from variable-frequency device. And total dissipative power of each harmonic is equal to zero. These conclusions can also be verified by the traditional harmonic analysis. The oscillation solutions which consist of the mixture of three main harmonics possess very long oscillation period, the spectral distribution are very tight, similar to evolution from doubling period leading to chaos. It can be illustrated that the chaos is sufficient or infinite extension of the oscillation period. In fact, the oscillation solutions plotted by numerical simulation all are certainly a periodic function of discrete spectrum. When phase portrait plotted hasn’t finished one cycle, it is shown as aperiodic chaos.

A novel low-complexity power allocation algorithm based on the NOMA system in a low-speed environment

For future wireless communication systems,Power Domain Non-Orthogonal Multiple Access(PD-NOMA)using an advanced receiver has been considered as a promising radio access technology candidate.Power allocation plays an important role in the PD-NOMA system because it considerably affects the total throughput and Geometric Mean User Throughput(GMUT)performance.However,most existing studies have not completely accounted for the computational complexity of the power allocation process when the User Terminals(UTs)move in a slow fading channel environment.To resolve such problems,a power allocation method is proposed to considerably reduce the search space of a Full Search Power(FSP)allocation algorithm.The initial power reallocation coefficients will be set to start with former optimal values by the proposed Lemma before searching for optimal power reallocation coefficients based on total throughput performance.Step size and correction granularity will be adjusted within a much narrower power search range while invalid power combinations may be reasonably discarded during the search process.The simulation results show that the proposed power reallocation scheme can greatly reduce computational complexity while the total throughput and GMUT performance loss are not greater than 1.5%compared with the FSP algorithm.

Magic Numbers of the Great Pyramid: A Surprising Result

Recently attention has been drawn to the frequently observed fifth power of the golden mean in many disciplines of science and technology. Whereas in a forthcoming contribution the focus will be directed towards Fibonacci number-based helical structures of living as well as inorganic matter, in this short letter the geometry of the Great Pyramid of the ancient Egyptians was investigated once more. The surprising main result is that the ratio of the in-sphere volume of the pyramid and the pyramid volume itself is given by π⋅φ5, where φ = 0.618033987⋅⋅⋅ is nature’s most important number, the golden mean. In this way not only phase transitions from microscopic to cosmic scale are connected with φ5, also ingenious ancient builders have intuitively guessed its magic before.

Optimized Complex Power Quality Classifier Using One vs. Rest Support Vector Machines

Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power quality classification techniques focused on single power quality events and did not include an optimal feature selection process. This paper presents a classification system that employs Wavelet Transform and the RMS profile to extract the main features of the measured waveforms containing either single or complex disturbances. A data mining process is designed to select the optimal set of features that better describes each disturbance present in the waveform. Support Vector Machine binary classifiers organized in a “One Vs Rest” architecture are individually optimized to classify single and complex disturbances. The parameters that rule the performance of each binary classifier are also individually adjusted using a grid search algorithm that helps them achieve optimal performance. This specialized process significantly improves the total classification accuracy. Several single and complex disturbances were simulated in order to train and test the algorithm. The results show that the classifier is capable of identifying >99% of single disturbances and >97% of complex disturbances.

Industrial Policy and the Great Power Competition

Since the end of the Cold War,major powers have avoided direct military confrontation,wary of the devastating consequences of nuclear warfare.Yet the arms race and regional conflicts remain important forms of power competition.Nonetheless,in the era of globalization,rapid advancements in new technologies and industries have eclipsed the utility of geopolitical maneuvers and military competition.In today’s world,the great power competition goes beyond the arms race and GDP aggregates.What matters more is the race to innovate and apply new technologies through a complete range of industrial sectors.In a world where technology has a controlling influence,industrial security has become the linchpin of national security.As globalization reshapes the world’s industrial landscape,a country’s economic influence,military might and national security depend increasingly on its industrial structure.National security is contingent upon industrial strength.In the era of globalization,industrial policy,cutting-edge technologies and market size are dominant factors influencing a country’s competitive position.The essence of the great power competition are industrial policies that fully unlock a country’s industrial potential and implementation of the policies.