Underwater Acoustic Communication System Based on MC-MFSK

2014 ◽  
Vol 556-562 ◽  
pp. 4897-4900 ◽  
Author(s):  
Chun Xian Gao ◽  
Hong Xing Yang ◽  
Fei Yuan ◽  
En Cheng
Keyword(s):  
Frame Structure ◽  
Underwater Acoustic Communication ◽  
Water Pool ◽  
The Core ◽  
System A ◽  
Time Space ◽  
Class D ◽  
Space Frequency ◽  
Hardware Circuit ◽  
Information Frame

For the time-space-frequency varying shallow water acoustic channel, we designed a multi-carrier FH-MFSK system, so that it can be reliably transmitted over these channels. This paper also design of a wake-up signal, and synchronization obtain information frame structure, the simulation result of the algorithm is presented. In the core of DSPC6747 chip, with class D power amplifier, we designed a reasonable layout, stable and reliable hardware circuit. By simulation, adding noise experiments, and water pool experiments verify the good performance of the system, a very low bit error rate (BER) communications were archived.

MINERAL DEPOSITS OF THE MIDCONTINENT RIFT SYSTEM - A NEW TIME/SPACE CLASSIFICATION

2018 ◽  
Author(s):  
Laurel G. Woodruff ◽  
◽  
Suzanne W. Nicholson ◽  
Connie L. Dicken ◽  
Klaus J. Schulz
Keyword(s):  
Mineral Deposits ◽  
Rift System ◽  
Midcontinent Rift ◽  
System A ◽  
Time Space ◽  
Midcontinent Rift System ◽  
New Time

A New Algorithm to Reduce PAPR in STBC MIMO-OFDM System

2013 ◽  
Vol 760-762 ◽  
pp. 190-193
Author(s):  
Ya Jing Wang ◽  
Ya Zhen Li ◽  
Jing Guan
Keyword(s):  
Ofdm System ◽  
The Core ◽  
Use Of Time ◽  
Time Space ◽  
Core Technology ◽  
Mimo Ofdm ◽  
Papr Performance ◽  
And Inversion ◽  
Development Prospects ◽  
Great Development

MIMO and OFDM technology is the core technology of 4G network, and have great development prospects. The main drawback of MIMO-OFDM system is the high PAPR. This paper is based on Cross-antenna rotation and inversion and Active Constellation Extension. The paper proposed the joint algorithm to reduce PAPR in STBC MIMO-OFDM system. It makes use of time, space and frequency freedom to improve the PAPR performance. The simulation results show that the joint algorithm can effectively reduce the PAPR value and do not increase the bit error rate in STBC MIMO-OFDM system.

Modeling and analysis of LOFAR scintillation data

2021 ◽  
Author(s):  
Marcin Grzesiak ◽  
Mariusz Pożoga ◽  
Barbara Matyjasiak ◽  
Dorota Przepiórka ◽  
Hanna Rothkaehl ◽  
...  
Keyword(s):  
Full Range ◽  
Cosmic Radio ◽  
Radio Emissions ◽  
Modeling And Analysis ◽  
Plasma Irregularities ◽  
Time Space ◽  
Cosmic Medium ◽  
Evolution Characteristics ◽  
Space Frequency ◽  
Good Coverage

<p>Scintillation of beacon satellite signals or distant cosmic radio emissions can provide interesting information on the cosmic medium itself, its internal spatial structure and basic evolution characteristics. LOFAR network gives consistent scintillation data with good coverage both in time and space and for the frequency range that goes down close to the local plasma frequency (LBA) being thus sensible to ionospheric plasma irregularities. LOFAR Scintillation measurements in the LBA range exhibit very interesting morphologies. Based on scintillation simulations using the phase screen method, including multiple scattering and refraction, we try to untangle the information contained in the full range (time, space, frequency) of LOFAR data and verify a number of hypotheses about the local structure of the ionosphere and its evolution.</p>

Introduction

2019 ◽  
pp. 1-54
Keyword(s):  
Jim Crow ◽  
Federal State ◽  
Late Nineteenth Century ◽  
Indian Reservations ◽  
The Core ◽  
Detention Centers ◽  
Time Space ◽  
Early Twenty ◽  
Immigrant Detention ◽  
Jim Crow South

The introduction analyzes the ways in which distinct regimes of incarceration and removal—from jails and prisons to Indian reservations and immigrant detention centers and deportation trains—have constituted what Michel Foucault has called a “carceral continuum, network and archipelago” that stretches across time, space, and region. Foucault defined this “carceral continuum” as a disciplinary network where the prison served as the core and root of carceral power but where different branches of other carceral regimes entwined. The introduction expands Foucault’s “carceral continuum” to explore how a variety of federal, state, local, and privatized institutions developed from the late nineteenth century to the early twenty-first. The introduction situates overlapping “carceral networks” as the core nexus that connects otherwise distinct historiographies of the American West, the Jim Crow South, and the U.S.-Mexico borderlands. As a collection of essays that analyzes the intersection of carceral networks across different regions and transnationally between different nations, the introduction addresses a historiography of carceral literature that is often defined by its attachment to regional characteristics and different methodological approaches. The introduction concludes that the intersection of these carceral states may yet provide the critical lens needed to dismantle the tangled state of mass incarceration.

The Satiation of Natural Curiosity

2016 ◽  
Vol 5 (2) ◽  
pp. 27-34 ◽  
Author(s):  
Felix Schoeller
Keyword(s):  
Environmental Conditions ◽  
Dynamic Equilibrium ◽  
Human Mind ◽  
Cognitive System ◽  
Accurate Description ◽  
Internal Representations ◽  
The Core ◽  
System A

At the core of this essay is the idea that cognition is best described as a highly developed homeostatic device aiming to maintain a dynamic equilibrium between internal representations and changes in environmental conditions. The author emphasizes the fundamental role played by aesthetics in facilitating an accurate description of the human mind and introduce basic elements of a theory accounting for the influence of art on the cognitive system. A general bibliography is provided for the reader unfamiliar with the notions and desirous to pursue the analysis further.

Perceived Level of Benefits and Risk Core Functionalities of an EHR System

2011 ◽  
pp. 297-312 ◽  
Author(s):  
Diane C. Davis ◽  
Minal Thakkar
Keyword(s):  
Significant Relationship ◽  
Institute Of Medicine ◽  
The Core ◽  
System A ◽  
The Status ◽  
Research Questions ◽  
Results Management ◽  
Core Functionality ◽  
Benefit And Risk

The need to adopt an electronic health record (EHR) system in United States (U.S.) hospitals seems to be more and more obvious when evaluating the benefits of improved patient safety, quality of care, and efficiency. The purpose of the study was to identify the status of EHR systems in U.S. hospitals in regard to the core functionalities implemented (as identified by the Institute of Medicine) and to determine if there was a significant relationship between perceived level of benefit and risk with the use of each core functionality, as well as if there was a significant relationship between the status of the EHR system and size of hospital. A national survey of U.S. hospitals was conducted to answer the research questions. The results showed that 37% had some components in all.of the core functionalities of an EHR system, while 27% were using at least some functionalities. Health information and data, administrative processes, and results management were the three core functionalities that a majority of hospitals had as a part of their EHR system. A significant positive correlation between perceived benefits and risks was found in all of the eight core functionalities. There was no significant relationship found between status of EHR system and size of hospitals.

Conceptualization of the acidification theory in Swedish environmental research

1996 ◽  
Vol 4 (2) ◽  
pp. 123-132
Author(s):  
Gunilla Ôberg ◽  
Karin Bäckstrand
Keyword(s):  
Scientific Community ◽  
Qualitative Content Analysis ◽  
Research Process ◽  
Environmental Research ◽  
Review System ◽  
The Core ◽  
System A ◽  
Chain Of Evidence ◽  
Hidden Patterns ◽  
Empirical Material

The aim of the present study was to describe and analyse the process of formulating the acidification theory in the Swedish research community. The empirical material was limited to articles written by Swedish researchers during the period 1950–1989 and published in international scientific journals utilizing a peer-review system. A model was developed to represent what Swedish researchers have regarded as the core of the acidification theory. Guided by the developed model, a qualitative content analysis of the scientific articles was conducted; i.e., we examined how central components and causal relationships of the theory have been explained and discussed. It should be emphasized that the present article describes an investigation of science itself (i.e., science in action) and is not an up-to-date review of acidification research. Our analysis revealed that some parts of the chain of evidence underlying the acidification theory were accepted before they were scrutinized by the scientific community and that the acidification complex was not conceptualized in accordance with the conceptualization of its various components. Actually, the acidification problem as a whole (i.e., the sum of all of its components) was not treated as a scientific theory that needed to be evaluated. This strongly indicates that the conceptualization was guided by factors that are generally, within the scientific community, considered to be external to the research process. There is no evidence that Swedish acidification research has adhered less stringently to scientific norms than environmental research in general has. Indeed, it is likely that such hidden patterns normally influence the conceptualization of science and we, therefore, conclude that the influence of factors that are not strictly a part of the research process must be further elucidated if the prerequisites and implications of research are to be clarified.Key words: scientific conceptualization, research process, acidification.

3D Wavelet Multiresolution of Multiphase Flow CT Images

2002 ◽  
Author(s):  
Masahiro Takei ◽  
Hui Li ◽  
Mitsuaki Ochi ◽  
Yoshifuru Saito ◽  
Kiyoshi Horii
Keyword(s):  
Cross Section ◽  
Density Fluctuation ◽  
Particle Density ◽  
Three Dimensional ◽  
Density Fluctuations ◽  
Time Space ◽  
Bent Pipe ◽  
Space Frequency ◽  
Pass Through ◽  
Discrete Wavelets

The extraction of dominant particle density fluctuation in various time-space frequency levels on a pipeline cross section was performed using capacitance-computed tomography and three-dimensional discrete wavelets transform. As a result, particle density fluctuation downstream of a bent pipe is decomposed into the time-space levels in a non-choking state and a pseudo-choking state. The proposed method enables realization of the time and position at which particle density fluctuations with respect to dominant time-space levels pass through the pipeline.

The Pulse in the Machine: Automating Tibetan Diagnostic Palpation in Postsocialist Russia

2015 ◽  
Vol 57 (2) ◽  
pp. 407-434 ◽  
Author(s):  
Tatiana Chudakova
Keyword(s):  
Soviet Union ◽  
Diagnostic System ◽  
Diagnostic Techniques ◽  
Tibetan Medicine ◽  
The Core ◽  
System A ◽  
The Soviet Union ◽  
National Public Health ◽  
Knowledge And Practice ◽  
Forms Of Knowledge

AbstractThis article analyzes efforts by Soviet and present-day scientists in Russia to “rationalize” and ultimately automate the diagnostic techniques of Tibetan medicine. It tracks the institutional and conceptual histories of designing a pulse diagnostic system, a project that began in the Soviet Union in the early 1980s. It has recently been re-enlivened in Buryatia, an ethnic minority region in Southeastern Siberia, in efforts to mobilize indigenous medical practices in response to local and national public health concerns. I focus on the translational ideologies that informed efforts to develop the pulsometer as a medical imaging technology, and analyze obstacles to these efforts found at the core of the device. Scientists working on the pulsometer have systematically tried to discern whether their measurements indicate sustained bodily pathologies, or instead reflect only technological white noise, and they still recruit and rely on the embodied expertise of practitioners of Tibetan medicine to validate their findings. In so doing they reaffirm claims that Tibetan medicine in Buryatia is inextricable from the forms of knowledge and practice that their projects work to standardize. I show how the apparent failures at perfect mechanization have made the pulsometer a surprisingly productive site for creating new kinds of expert communities and forms of knowledge making.

Tunable Athermal Multi-FBG Package Using a Bending Bimetal Structure

2000 ◽  
Vol 124 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Samuel I-En Lin
Keyword(s):  
Temperature Compensation ◽  
Fiber Optic ◽  
Compensation Mechanism ◽  
Central Wavelength ◽  
Experimental Procedure ◽  
The Core ◽  
System A ◽  
Stable Temperature ◽  
Fiber Optic Communication ◽  
Optic Communication

The Fiber Bragg Gratings (FBGs) written by ultraviolet light into the core of an optical fiber have developed into a critical component for many applications in the fiber-optic communication system. A stable temperature compensation mechanism is essential to the successful usage of FBG-based devices. In this paper, the bimetal-based temperature-compensating package with tunable mechanism was developed. Such a tunable mechanism serves as prestress and post-tuning mechanisms of fixture in order to obtain a predetermined central wavelength. With the aid of developed experimental procedure, this compact and easily manufactured package can achieve temperature coefficient of 8.3×10−4 nm/°C in the temperature range from −40°C to 80°C. The same package can also be used for multi-FBG applications.

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