scholarly journals Design of the Optimum Execution Stage of Embedded Processors

Author(s):  
Masa-aki Fukase

We describe the optimum design of an execution stage for embedded processors. The execution stage is the core of embedded processors to treat basic applications for multimedia, communication and control. Considering algorithms in running such applications, the design principle of embedded processors is to achieve reliability, precision, low power, high speed and fast throughput altogether. However, it is hard to sufficiently clear the design principle by existing microprocessor technology. The one of difficult issues is the mixed sequence of integer and FP (floating point) arithmetic instructions. The different latencies of these instructions in a processor’s execution stage surely make the pipelined processing disturb and degrade throughput. The solution for this problem in this study is a wave-pipelined MFU (multifunctional unit) that is the multifunctionalization and wave-pipelining of different FUs (functional units). The high speed characteristic of wave-pipeling guarantees the reliability of processor behavior that is free from timing error. Thus, the waved MFU agrees well with overall trade-off design. In order to complement the shortage of the standard CAD tools, we explored the HS/SW (hardware/software) co-design for the waved MFU. Experimental results by using a 0.18-m CMOS standard cell technology showed the usefulness of this approach.

2015 ◽  
Vol 734 ◽  
pp. 332-335
Author(s):  
Fei Wang ◽  
Rong Rong Wu ◽  
Li Qiang Wang ◽  
Si Yuan Wu

Precision motion system is driven directly by high frequency linear motion platform, eliminating the adverse effects brought by mechanical transmission, and greatly improving the rapid reaction capability and the control accuracy of feedback system. The linear motion platform is widely used in various types of high-speed, precision machining equipment. In the paper, the one-dimensional linear motion platform is described, and design solution of mechanical part and control system is also introduced, including working principle and structure of voice coil motor, control methods of grating sensors, circuit of grating sensor, drive and control circuit. Displacement control, speed control and output force control of the one-dimensional linear motion control platform can be achieved. So the one-dimensional linear motion platform can be applied in the movement device in high-precision and high-speed.


1996 ◽  
Vol 118 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Sergio Bittanti ◽  
Fabrizio Lorito ◽  
Silvia Strada

In this paper, Linear Quadratic (LQ) optimal control concepts are applied for the active control of vibrations in helicopters. The study is based on an identified dynamic model of the rotor. The vibration effect is captured by suitably augmenting the state vector of the rotor model. Then, Kalman filtering concepts can be used to obtain a real-time estimate of the vibration, which is then fed back to form a suitable compensation signal. This design rationale is derived here starting from a rigorous problem position in an optimal control context. Among other things, this calls for a suitable definition of the performance index, of nonstandard type. The application of these ideas to a test helicopter, by means of computer simulations, shows good performances both in terms of disturbance rejection effectiveness and control effort limitation. The performance of the obtained controller is compared with the one achievable by the so called Higher Harmonic Control (HHC) approach, well known within the helicopter community.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Hongfang Ma ◽  
Rui Li ◽  
Longguang Jiang ◽  
Songlin Qiao ◽  
Xin-xin Chen ◽  
...  

AbstractPorcine reproductive and respiratory syndrome (PRRS) is a serious disease burdening global swine industry. Infection by its etiological agent, PRRS virus (PRRSV), shows a highly restricted tropism of host cells and has been demonstrated to be mediated by an essential scavenger receptor (SR) CD163. CD163 fifth SR cysteine-rich domain (SRCR5) is further proven to play a crucial role during viral infection. Despite intense research, the involvement of CD163 SRCR5 in PRRSV infection remains to be elucidated. In the current study, we prepared recombinant monkey CD163 (moCD163) SRCR5 and human CD163-like homolog (hCD163L1) SRCR8, and determined their crystal structures. After comparison with the previously reported crystal structure of porcine CD163 (pCD163) SRCR5, these structures showed almost identical structural folds but significantly different surface electrostatic potentials. Based on these differences, we carried out mutational research to identify that the charged residue at position 534 in association with the one at position 561 were important for PRRSV-2 infection in vitro. Altogether the current work sheds some light on CD163-mediated PRRSV-2 infection and deepens our understanding of the viral pathogenesis, which will provide clues for prevention and control of PRRS.


Author(s):  
Andrew Linn ◽  
Anastasiya Bezborodova ◽  
Saida Radjabzade

AbstractThis article presents a practical project to develop a language policy for an English-Medium-Instruction university in Uzbekistan. Although the university is de facto English-only, it presents a complex language ecology, which in turn has led to confusion and disagreement about language use on campus. The project team investigated the experience, views and attitudes of over a thousand people, including faculty, students, administrative and maintenance staff, in order to arrive at a proposed policy which would serve the whole community, based on the principle of tolerance and pragmatism. After outlining the relevant language and educational context and setting out the methods and approach of the underpinning research project, the article goes on to present the key findings. One of the striking findings was an appetite for control and regulation of language behaviours. Language policies in Higher Education invariably fall down at the implementation stage because of a lack of will to follow through on their principles and their specific guidelines. Language policy in international business on the other hand is characterised by a control stage invariably lacking in language planning in education. Uzbekistan is a polity used to control measures following from policy implementation. The article concludes by suggesting that Higher Education in Central Asia may stand a better chance of seeing through language policies around English-Medium Instruction than, for example, in northern Europe, based on the tension between tolerance on the one hand and control on the other.


2021 ◽  
pp. 053901842199894
Author(s):  
Frank Adloff ◽  
Iris Hilbrich

Possible trajectories of sustainability are based on different concepts of nature. The article starts out from three trajectories of sustainability (modernization, transformation and control) and reconstructs one characteristic practice for each path with its specific conceptions of nature. The notion that nature provides human societies with relevant ecosystem services is typical of the path of modernization. Nature is reified and monetarized here, with regard to its utility for human societies. Practices of transformation, in contrast, emphasize the intrinsic ethical value of nature. This becomes particularly apparent in discourses on the rights of nature, whose starting point can be found in Latin American indigenous discourses, among others. Control practices such as geoengineering are based on earth-systemic conceptions of nature, in which no distinction is made between natural and social systems. The aim is to control the earth system as a whole in order for human societies to remain viable. Practices of sustainability thus show different ontological understandings of nature (dualistic or monistic) on the one hand and (implicit) ethics and sacralizations (anthropocentric or biocentric) on the other. The three reconstructed natures/cultures have different ontological and ethical affinities and conflict with each other. They are linked to very different knowledge cultures and life-worlds, which answer very differently to the question of what is of value in a society and in nature and how these values ought to be protected.


2020 ◽  
pp. 1-17
Author(s):  
Francisco Javier Balea-Fernandez ◽  
Beatriz Martinez-Vega ◽  
Samuel Ortega ◽  
Himar Fabelo ◽  
Raquel Leon ◽  
...  

Background: Sociodemographic data indicate the progressive increase in life expectancy and the prevalence of Alzheimer’s disease (AD). AD is raised as one of the greatest public health problems. Its etiology is twofold: on the one hand, non-modifiable factors and on the other, modifiable. Objective: This study aims to develop a processing framework based on machine learning (ML) and optimization algorithms to study sociodemographic, clinical, and analytical variables, selecting the best combination among them for an accurate discrimination between controls and subjects with major neurocognitive disorder (MNCD). Methods: This research is based on an observational-analytical design. Two research groups were established: MNCD group (n = 46) and control group (n = 38). ML and optimization algorithms were employed to automatically diagnose MNCD. Results: Twelve out of 37 variables were identified in the validation set as the most relevant for MNCD diagnosis. Sensitivity of 100%and specificity of 71%were achieved using a Random Forest classifier. Conclusion: ML is a potential tool for automatic prediction of MNCD which can be applied to relatively small preclinical and clinical data sets. These results can be interpreted to support the influence of the environment on the development of AD.


2021 ◽  
pp. 1-7
Author(s):  
Renata da R. M. Rodrigues ◽  
Bruna K. Hassan ◽  
Michele R. Sgambato ◽  
Bárbara da S. N. Souza ◽  
Diana B. Cunha ◽  
...  

Abstract School-based studies, despite the large number of studies conducted, have reported inconclusive results on obesity prevention. The sample size is a major constraint in such studies by requiring large samples. This pooled analysis overcomes this problem by analysing 5926 students (mean age 11·5 years) from five randomised school-based interventions. These studies focused on encouraging students to change their drinking and eating habits, and physical activities over the one school year, with monthly 1-h sessions in the classroom; culinary class aimed at developing cooking skills to increase healthy eating and attempts to family engagement. Pooled intention-to-treat analysis using linear mixed models accounted for school clusters. Control and intervention groups were balanced at baseline. The overall result was a non-significant change in BMI after one school year of positive changes in behaviours associated with obesity. Estimated mean BMI changed from 19·02 to 19·22 kg/m2 in the control group and from 19·08 to 19·32 kg/m2 in the intervention group (P value of change over time = 0·09). Subgroup analyses among those overweight or with obesity at baseline also did not show differences between intervention and control groups. The percentage of fat measured by bioimpedance indicated a small reduction in the control compared with intervention (P = 0·05). This large pooled analysis showed no effect on obesity measures, although promising results were observed about modifying behaviours associated with obesity.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng Zhang ◽  
Ryo Noguchi ◽  
Kenta Kuroda ◽  
Chun Lin ◽  
Kaishu Kawaguchi ◽  
...  

AbstractA quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.


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