Locked State Research Articles

The static friction force in commensurate structures with an asymmetric deformable substrate potential

It is used that a series of interacting atoms subjected in an asymmetric deformable substrate potential. With the increase of external driving force, the system moves from locked state to sliding state. This critical force is also known as depinning force or the maximum static friction force. It has been analyzed for the shape parameter.

A Comprehensive Study of Air Transport Liberalization Through the Lens of Strategic Airline Alliances

The present study examines the issue of the liberalization of air transport through the lens of strategic airline alliances. Alliances are seen as a corollary to the suboptimal regulatory framework governing international civil aviation, stemming from ‘the nationality rule’. The ‘nationality rule’ provides that majority ownership and effective control of an airline must be vested in the country that designates it. This requirement has nurtured the establishment of national airlines and has prevented the industry from consolidating out of fear that traffic rights, negotiated bilaterally between States, will be lost. What is more, it has locked States into a ‘prisoner’s dilemma’, stalling liberalization. Airlines have reacted by forging alliances to emulate mergers and reap merger-like efficiencies. The present study examines the way that the airline industry has positioned itself strategically within the suboptimal regulatory framework in order to unleash the benefits of liberalization. It finds that the model of open skies, metal neutrality and antitrust immunity, pioneered by KLM and Northwest in 1992, has embedded a degree of de facto liberalization. Twenty-five years after its introduction, this model seems to have exhausted its liberalizing potential, threatening to lock States into yet another prisoner’s dilemma. The International Civil Aviation Organization (ICAO) is presently preparing a broad programme to deal with a wide variety of aspects of air transport liberalization, including airline alliances. The present study aims to contribute to the ICAO’s research effort and, more broadly, to the long list of works on air transport liberalization.

A Single-Event Transient-Tolerant High-Frequency CMOS Quadrature Phase Oscillator

High-frequency oscillators developed in CMOS technologies for space applications are vulnerable to single-event transient (SET) effects caused by ionizing radiation strikes. We have designed a phase-locked loop (PLL) with a quadrature phase current-controlled oscillator (QCCO) to overcome this limitation. The feedback mechanism in the QCCO helps in improving the SET tolerance, while parallel coupling achieves wide tuning range. The oscillator is irradiated with laser pulses at a certain pulse repetition frequency, which results in spurious tones in the oscillator output spectrum. The strengths of these spurs are used for evaluating the SET tolerance of the oscillator. Under identical conditions, experiments show that the QCCO has an average of 15-dB lower spur level compared to a conventional single-phase $LC$ voltage-controlled oscillator (SVCO) and an SVCO-based PLL loses lock at a certain laser pulse energy, while the QCCO-based PLL remains in the locked state. These results confirm that the QCCO significantly improves the reliability of high-frequency PLLs in radiation environments.

Self-Power Saving Technique in State Machine Circuit of Automatic Teller Machine Application

In a finite state machine (FSM), there is only one active state while the other states are in idle states simultaneously. Thus, only one state is required to power up, the other states can be switched off to save active power. Normally, a backward traversing algorithm is used to label the power gating cells and extract the enable signals for combinational logic gates in reducing the active power consumption. This conventional power gating technique uses the extracted enable signals to turn ON/OFF these inserted NMOS switches. Then, a power management unit is required to manage these enable signals and detect the idle periods. The proposed self-power saving technique uses internally generated enable signals from state transitions to control NMOS switches inserted under the ground rail of each state. All internal enable signals are created to activate/deactivate the machine states at the same time. Based on the next state of the FSM, a decoder creates the enable signals for each state to do power gating in an Automatic Teller Machine (ATM) application. The isolation cell is designed to isolate the current state and next state for retaining data. Simulation results show the power saving from 31.99% at a WAIT state to 82.87% at a LOCK state, depending on the current state of the finite state machine. On average, the power loss is saved up to 63.2% in the FSM. An overhead area is about 12% compared to the conventional technique while timing overhead is under 5%.

Chaos Control of Third Order Phase Locked Loop Using Sliding Mode Nonlinear Controller

The nonlinear dynamics of a third-order phase locked loop (PLL) reveals a chaotic behavior for range values of loop parameter. Using bifurcation theory, it has been verified through mathematical analysis and simulation that such behavior pulls the PLL to an undesirable and unstable out-of-lock state. This paper aims to control such chaotic behavior and drive the PLL to the in-lock state, by applying a nonlinear controller based on sliding mode control theory to the PLL under consideration. The design process involves two phases. In the first phase, a sliding surface is designed such that the sliding motion meets the design specifications. In the second phase, a high-speed switching control law is selected such that the system state trajectory reaches the sliding surface. The validity of the proposed controller is tested through simulations. Results show the effectiveness of the designed nonlinear controller in stabilizing the system and driving the PLL to the phase locked state.

Power and phase dynamics of injection-locked spin torque nano-oscillators under conservative and dissipative driving signals

To describe all possible injection locking configurations of spin torque nano-oscillators (STNO), previous analytical descriptions are extended by introducing the most general form of the driving force: ℱ ∝ +. We provide the expressions of the corresponding forcing functions ℱ for the six basic conservative and dissipative forcing torques (~ × and ~ × × with = , ,), and demonstrate at the example of a uniform in-plane magnetized STNO, that the general case (| | | |) as well as special cases, can occur depending on: (i) the nature of the forcing torque, (ii) the direction with respect to the equilibrium direction, (iii) the harmonic order and (iv) the operation point (dc current). These relations provide a straightforward means to analyze more complex forcing torques such as a rotating field or the superposition of damping-like and field-like spin transfer torques. Besides the phase properties we also address in detail the power properties of the injection locked state for which two new parameters are introduced: the locking power range and the power angle. They can provide important complementary information on the driving forces from experiment. The general description presented here is not limited to STNOs and is valid for any non-isochronous auto-oscillator driven by an elliptical forcing of conservative or dissipative nature.

Interpretable Relative Squeezing bottleneck design for compact convolutional neural networks model

Convolutional neural networks (CNN) are mainly used for image recognition tasks. However, some huge models are infeasible for mobile devices because of limited computing and memory resources. In this paper, feature maps of DenseNet and CondenseNet are visualized. It could be observed that there are some feature channels in locked state and some have similar distribution property, which could be compressed further. Thus, in this work, a novel architecture — RSNet is introduced to improve the computing efficiency of CNNs. This paper proposes Relative-Squeezing (RS) bottleneck design, where the output is the weighted percentage of input channels. Besides, RSNet also contains multiple compression layers and learned group convolutions (LGCs). By eliminating superfluous feature maps, relative squeezing and compression layers only transmit the most significant features to the next layer. Less parameters are employed and much computation is saved. The proposed model is evaluated on three benchmark datasets: CIFAR-10, CIFAR-100 and ImageNet. Experiment results show that RSNet performs better with less parameters and FLOPs, compared to the state-of-the-art baseline, including CondenseNet, MobileNet and ShuffleNet.

Can quantum fluctuation enhance diffusion in a corrugated plane?

By means of the effective diffusion coefficient of a particle be determined by the envelope width of its spatial distribution, we study the influence of quantum fluctuation upon the diffusion of the particle in a corrugated plane. The model allows for a power-spectrum quantum noise and a biased periodic potential. A comprehensive method is developed, which includes three techniques: the fast Fourier transform is used to generate quantum colored noise, solving numerically the generalized Langevin equation by the Monte-Carlo method, and the quantum-averaging correction of nonlinear force is taken account into the calculation. The prominent result is demonstrated that the effective diffusion coefficient of the particle driven by quantum thermal noise is less than the classical one when the biased force arrives at its critical value, where the local minima of potential vanish just. Moreover, the time index of the position variance of a super-Ohmic damping particle varies with the biased force. This is due to a fact that the motion of particle exhibits mixing of the locked and running states in such potential, however, the quantum fluctuation increases mobility but decreases the probability of the particle in a locked state.

Optimizing a soil gas monitoring network layout across faults based on a seismogenic model

We undertake a sturdy body seismogenic model study along the northern margin of the West Qinling fault zone, China, to address some existing problems of neglecting scientific layout based on certain prediction theory and observation facts surrounding underground fluid monitoring networks across faults. A combination of high-density underground fluid measurements and vertical crustal deformation and seismological observations were used to elucidate the interplay between fluid dynamics, crustal deformation, and seismic activity and to comprehensively analyze the fault segment characteristics along the fault zone. We found correspondence between these parameters along the northern margin of the West Qinling fault zone. All parameters showed higher values in the Wu Shan (WS) segment than in the western Xia He–Huang Xiang Gou–Zhang Xian (XH-HXG-ZX) segment and eastern Tian Shui (TS) area. The 222Rn concentration reached 5.0942 at BZC, and the Hg concentration reached 3.4398 at LJG in WS. Similarly, the vertical crustal deformation and seismic activity in this area were both stronger than those in the western XH–HXG–ZX and TS area. Based on the sturdy body seismogenic model, we found that the ZX and TS segments exhibited weaker activity than the surrounding areas and may be in a deep locked state under the corresponding regional stress. Compared with existing monitoring network for background value detection and comprehensive research results, we propose a technical underground flow monitoring network prototype that includes two grade I and five grade II survey sites along the northern margin of the West Qinling fault zone based on the sturdy body seismogenic model. This prototype will provide a more reliable basis for earthquake prediction, tracking and mitigation, and disaster risk reduction. The presented scheme can be used as a guideline for deploying fault soil gas monitoring networks in China.

CapZ integrates several signaling pathways in response to mechanical stiffness.

Muscle adaptation is a response to physiological demand elicited by changes in mechanical load, hormones, or metabolic stress. Cytoskeletal remodeling processes in many cell types are thought to be primarily regulated by thin filament formation due to actin-binding accessory proteins, such as the actin-capping protein. Here, we hypothesize that in muscle, the actin-capping protein (named CapZ) integrates signaling by a variety of pathways, including phosphorylation and phosphatidylinositol 4,5-bisphosphate (PIP2) binding, to regulate muscle fiber growth in response to mechanical load. To test this hypothesis, we assess mechanotransduction signaling that regulates muscle growth using neonatal rat ventricular myocytes cultured on substrates with the stiffness of the healthy myocardium (10 kPa), fibrotic myocardium (100 kPa), or glass. We investigate how PIP2 signaling affects CapZ using the PIP2 sequestering agent neomycin and the effect of PKC-mediated CapZ phosphorylation using the PKC-activating drug phorbol 12-myristate 13-acetate (PMA). Molecular simulations suggest that close interactions between PIP2 and the β-tentacle of CapZ are modified by phosphorylation at T267. Fluorescence recovery after photobleaching (FRAP) demonstrates that the kinetic binding constant of CapZ to sarcomeric thin filaments in living muscle cells increases with stiffness or PMA treatment but is diminished by PIP2 reduction. Furthermore, CapZ with a deletion of the β-tentacle that lacks the phosphorylation site T267 shows increased FRAP kinetics with lack of sensitivity to PMA treatment or PIP2 reduction. Förster resonance energy transfer (FRET) probes the molecular interactions between PIP2 and CapZ, which are decreased by PIP2 availability or by the β-tentacle truncation. These data suggest that CapZ is bound to actin tightly in the idle, locked state, with little phosphorylation or PIP2 binding. However, this tight binding is loosened in growth states triggered by mechanical stimuli such as substrate stiffness, which may have relevance to fibrotic heart disease.

A signature dish of Bihar: Litti and Chokha

Bihar is a land locked state lying in the eastern part of India. The word Bihar comes from the Sanskrit word Vihara meaning Buddhist Monasteries. The Mauryan Empire rose from Magadha. Buddhism, which is one of the biggest religions in the world, originated in Bihar and it is also home to the ancient Nalanda University, which was a centre of learning established during the 5th century. Litti Chokha a remarkable dish which comes from the state of Bihar is not only popular in India today, but has also made a special mark globally. Litti and Chokha are absolutely delicious and is the rustic way of cooking.

Spin-layer locked gapless states in gated bilayer graphene.

Gated bilayer graphene exhibits spin-degenerate gapless states with a topological character localized at stacking domain walls. These states allow for one-dimensional currents along the domain walls. We herein demonstrate that these topologically protected currents are spin-polarized and locked in a single layer when bilayer graphene contains stacking domain walls decorated with magnetic defects. The magnetic defects, which we model as π-vacancies, perturb the topological states but also lift their spin degeneracy. One gapless state survives the perturbation of these defects, and its spin polarization is largely localized in one layer. The spin-polarized current in the topological state flows in a single layer, and this finding suggests the possibility of effectively exploiting these states in spintronic applications.

Management of Habitual Temporomandibular Joint Dislocation by Eminectomy

Temporomandibular joint (TMJ) dislocation(luxation) occurs when the condyle moves out of the glenoid fossa upon mouth opening and is locked anteriorly to the articular eminence. The dislocation leads to protective contraction or spasm of masticatory muscles, which reinforces the locked state, with or without pain. Usually, the episodes are triggered by any activities that lead to wide mouth opening such as yawning, laughing, and prolonged, excessive mouth opening during a dental or medical exam. It is a distressing and embarrassing situation for the patient. Repetitive dislocation of TMJ is defined as recurrent or habitual TMJ luxation. There are many treatment modalities available ranging from conservative approach to surgical approach. However, conservative approaches usually offer only a temporary solution and they have significant failure rate. Surgical approaches are available with varying degrees of success. Eminectomy is the most predictable surgical treatment for recurrent TMJ luxation. Herein, we report a case of a 47-year old male patient who was diagnosed with bilateral recurrent TMJ luxation that was successfully treated through bilateral eminectomy.

Direct thermo-optical tuning of silicon microresonators for the mid-infrared.

We use light from a visible laser diode to directly tune silicon-on-chip microresonators by thermo-optical effect. We show that this direct tuning is local, non invasive and has a much smaller time constant than global temperature tuning methods. Such an approach could prove to be highly effective for Kerr comb generation in microresonators pumped by quantum cascade lasers, which cannot be easily tuned to achieve comb generation and soliton-mode locked states.

Energy-efficient prediction of smartphone unlocking

We investigate the predictability of the next unlock event on smartphones, using machine learning and smartphone contextual data. In a 2-week field study with 27 participants, we demonstrate that it is possible to predict when the next unlock event will occur. Additionally, we show how our approach can improve accuracy and energy efficiency by solely relying on software-related contextual data. Based on our findings, smartphone applications and operating systems can improve their energy efficiency by utilising short-term predictions to minimise unnecessary executions, or launch computation-intensive tasks, such as OS updates, in the locked state. For instance, by inferring the next unlock event, smartphones can pre-emptively collect sensor data or prepare timely content to improve the user experience during the subsequent phone usage session.

Response of the Himalayan glacial cycles to multiple equilibrium of climate system: A review

The astronomical theory of Milankovitch supports the waxing and waning of ice sheets and polar glaciers by orbital forcing, excluding the fact that small changes in solar radiation flux are difficult to reconcile with the amplitude of glacial cycles. The numerical model explaining the 100 kyr problem has now revealed that the phase locking mechanism of orbital forcing has started to modulate the climatic transitions since ∼1.2 Myr back and remained locked till present climatic state (Rial et al., 2013). However, the true evidence to confirm it is not present. The present study is an attempt to comprehend the concept of synchronization of summer insolation modulation and internal climate forcing, responsible for glacial/interglacial termination present in and around the Himalaya-Tibet and worldwide. We present geographical evidences of glaciations from the Himalayan-Tibet region pointing out that responses (i.e. 18–24 kyr and 60–70 kyr BP glaciation events) are similar to the progression in climatic data and glaciations cycles for the last 100 kyr. The compelling evidence presents a possible explanation towards synchronized modulation of 100 kyr orbital cycles with 41 kyr obliquity cycles, coincidently resulting in unprecedentedly large glaciation around the last glacial cycle (60–70 kyr BP) and the Last Glacial Maxima (18–24 kys BP). By considering the influence of internal and external factors on glacier mechanism, we underline the most probable cause of 41 kyr cycle (obliquity) as the foremost driver of glaciations in the Himalaya and Tibet on longer timescales. We provide several lines of evidence to establish the possible connection of glaciation events and orbital cycles with the help of geographical and geological records consistent with the fact that resonance might be faded through time but the effect of frequency modulation still persists in the system.

Reversible Control of Spacing in Charged Lamellar Membrane Hydrogels by Hydrophobically Mediated Tethering with Symmetric and Asymmetric Double-End-Anchored Poly(ethylene glycol)s.

Complex materials often achieve their remarkable functional properties by hierarchical assembly of building blocks via competing and/or synergistic interactions. Here, we describe the properties of new double-end-anchored poly(ethylene glycol)s (DEA-PEGs)-macromolecules designed to impart hydrophobically mediated tethering attractions between charged lipid membranes. We synthesized DEA-PEGs (MW 2000 (2K) and 4.6K) with two double-tail (symmetric) or a double-tail and a single-tail (asymmetric) hydrophobic end anchors and characterized their equilibrium and kinetic properties using small-angle X-ray scattering. Control multilayer membranes without and with PEG lipid (i.e., single-end-anchored PEG) swelled continuously, with the interlayer spacing increasing between 30 and 90 wt % water content due to electrostatic as well as, in the case of PEG lipid, steric repulsion. In contrast, interlayer spacings in lamellar membrane hydrogels containing DEA-PEGs expanded over a limited water dilution range and reached a "locked" state, which displayed a near constant membrane wall-to-wall spacing (δw) with further increases in water content. Remarkably, the locked state displays a simple relation to the PEG radius of gyration δw ≈ 1.6 RG for both 2K and 4.6K PEG. Nevertheless, δw being considerably less than the physical size of PEG (2(5/3)1/2 RG) is highly unexpected and implies that, compared to free PEG, anchoring of the PEG tether at both ends leads to a considerable distortion of the PEG conformation confined between layers. Significantly, the lamellar hydrogel may be designed to reversibly transition from a locked to an unlocked (membrane unbinding) state by variations in the DEA-PEG concentration, controlling the strength of the interlayer attractions due to bridging conformations. The findings with DEA-PEGs have broad implications for hydrophobic-mediated assembly of lipid- or surfactant-coated building blocks with distinct shape and size, at predictable spacing, in aqueous environments.

Convergence and stability of generalized gradient systems by Łojasiewicz inequality with application in continuum Kuramoto model

The existence and uniqueness/multiplicity of phase locked solution for continuum Kuramoto model was studied in [12,29]. However, its asymptotic behavior is still unknown. In this paper we concern the asymptotic property of classic solutions to continuum Kuramoto model. In particular, we prove the convergence towards a phase locked state and its stability, provided suitable initial data and coupling strength. The main strategy is the quasi-gradient flow approach based on Łojasiewicz inequality. For this aim, we establish a Łojasiewicz type inequality in infinite dimensions for continuum Kuramoto model which is a nonlocal integro-differential equation. General theorems for convergence and stability of (generalized) quasi-gradient system in an abstract setting are also provided based on Łojasiewicz inequality.

8–10 Gbit/s full synthesised continuous‐half‐rate reference‐less all‐digital CDR with sub‐harmonic frequency extraction

Continuous-rate all-digital reference-less clock and data recovery (CDR) circuit that utilises a sub-harmonic extraction scheme for wide-range frequency detection is presented. In the proposed CDR, the capture range of the frequency locked loop (FLL) is extended to the tuning range of digital controlled oscillator, thanks to the subharmonic extraction scheme. The frequency errors of FLL in lock state are within the tracking range of CDR loop. The prototype reference-less all-digital CDR, fabricated using a 40 nm CMOS technology, successfully detects 8–10 Gbit/s PRBS 231 − 1 data and produces the recovered clock. The CDR consumes 29 mW from a supply voltage of 1 V for 10 Gbit/s input data. The measured RMS jitter of the recovered clock is 2.24 ps.

Investigation on the enhancement phenomenon of biased-diffusion in periodic potential

The noise-induced diffusion of a particle in a two-dimensional (2D) periodic potential is studied by simulating a general-damping Langevin equation, where the particle is subjected especially to both a constant force along a direction and an Ornstein–Uhlenbeck (OU) colored noise. The effective diffusion coefficient is determined by the envelope width of the spatial distribution of the particle. The enhancement phenomenon of diffusion from fluctuation-controlled one to bias-plus-correlation-controlled one is investigated. A scheme of local harmonic approximation for the OU colored noise is used to analyze our numerical findings, showing that the correlation effect of noise is beneficial to biased diffusion. Moreover, the dimensional effect is discussed by comparing the 1D and 2D treatments. The prominent result is demonstrated in the tilted periodic potential, namely, the motion of particle exhibits two modes: the locked state and the running state, thus the effective diffusion coefficient can be enhanced if the probability of a particle locked in local minima of the potential increases or the space distribution of the particle can be disintegrated into many small pieces.