GK Model Research Articles

Application of GK17 Ground-Motion Model to Preliminary Processed Turkish Ground-Motion Recordings Dataset and GK Model Adjustment to the Turkish Environment by Developing Partially Nonergodic Model

Abstract The global ergodic GK17 (Graizer, 2018) ground-motion model developed using the Next Generation Attenuation-West2 database (Ancheta et al., 2014) for the active crustal regions (ACRs) was applied to the dataset of recordings from the two largest moment magnitude Mw 7.8 and 7.5 earthquakes in Türkiye (Buckreis et al., 2023a). The GK17 model demonstrates acceptable performance while mostly underpredicting spectral accelerations (SAs) at near-fault up to ∼100 km and far-field more than ∼400 km rupture distances for periods T < 1 s. The GK17 model was modified by applying additional Rrup distance and VS30 residuals corrections, creating an updated GK nonergodic model tuned for Türkiye called the GK_T model. After varying anelastic attenuation of SAs QSA, it was concluded that the average for the ACRs value of QSA=120 produces the best results. Comparisons of the model site amplification functions (SAFs) show that the GK_T SAFs are lower compared to the GK17 model. The Türkiye-specific GK_T partially nonergodic model shows better agreement with the recorded data than the ergodic GK17 model, especially at short periods and short rupture distances. As expected, application of the Türkiye-specific model results in a lower sigma. It is also lower than the within-event sigma of the GK17 model, except for the period range of 1.5 < T < 3 s. Improvements to the GK_T model can be expected with an addition of deep sediment (basin depth) information to the current dataset and other earthquakes in the region.

Analytical Model for Thermoelastic Dissipation in Oscillations of Toroidal Micro/Nanorings in the Context of Guyer–Krumhansl Heat Equation

Thermoelastic dissipation or thermoelastic damping (TED) can restrict the quality factor of micro/nanoring resonators seriously. This paper employs the non-Fourier model of Guyer–Krumhansl (GK model) to render a size-dependent formulation and analytical solution for approximating the amount of TED in micro/nanorings with circular cross-section by inclusion of nonlocal and single-phase-lagging effects. To fulfill this objective, the equation of heat conduction in the ring is first established according to GK model. Then, by placing the temperature distribution obtained from the heat conduction equation in the TED relation defined on the basis of thermal energy approach, an expression in the form of infinite series is given for TED, which includes non-classical parameters of GK model. Finally, after checking the validity of the model through a comparative study, several simulation results are prepared to emphasize on the influence of different factors such as non-classical parameters of GK model, geometry of ring, vibrational mode and ambient temperature on TED value. Numerical examples reveal that the mentioned factors along with the two- or three-dimensional heat transfer (2D or 3D) model have major influences on TED variations.

On size-dependent generalized thermoelasticity of nanobeams

In this article, a size-dependent generalized thermoelasticity model is established to appraise the small-scale effect on thermoelastic vibrations of Euler-Bernoulli nanobeams. Small-scale effect on the structure and heat conduction is captured by exploiting nonlocal strain gradient theory (NSGT) and nonclassical heat conduction model of Guyer and Krumhansl (GK model). NSGT enables the model to account for both nonlocal and strain gradient effects on structure, and GK formulation empowers the model to incorporate both nonlocal and lagging effect into heat conduction equation. The normalized forms of size-dependent equations of motion and heat conduction are provided by introducing some dimensionless parameters. This system of normalized differential equations is then solved with the aid of the Laplace transform to determine thermoelastic responses of nanobeams. Through various examples, a complete parametric study is conducted to clarify the pivotal role of nonclassical scale parameters in thermoelastic behavior of nanobeams. Comparing the results extracted based on various relative magnitudes of nonlocal and strain gradient length scale parameters implies that NSGT is capable of expounding both hardening and softening phenomenon in nanoscale structures. The outcomes also reveal that GK model anticipates less energy dissipation.

Thermoelastic damping in rectangular microplate/nanoplate resonators based on modified nonlocal strain gradient theory and nonlocal heat conductive law

Size effect is a significant factor for accurate estimation of the thermoelastic damping (TED) in microplate/nanoplate resonators. The actual TED in microstructures/nanostructures is comprehensively affected by various size-dependent mechanisms in the mechanical and thermal field and studying only one of them may lead to one-sided conclusions. In this article, the governing equations of coupled thermoelasticity in a transversely vibrating rectangular plate are derived by the modified nonlocal strain gradient theory and the nonlocal heat conductive law (GK model). Then utilizing the energy approach, a size-dependent TED model for rectangular plates is presented in the form of infinite series. The constitutive boundary conditions are considered to close the nonlocal strain gradient problem in differential form. The silicon material with typical length scale parameters and relaxation time is selected in simulation. The influences of nonlocal elasticity, strain gradient elasticity and nonlocal heat conduction on TED in rectangular plates are investigated under different frequencies, thicknesses and boundary conditions. The simulation results show that the TED expression converges rapidly and the three size-dependent parameters have distinct influences on TED value, critical thickness and critical frequency. By taking advantage of the size effects reasonably, the quality of resonators can be improved.

"My Health" - A new coaching approach for empowering people to health activities in an integrated care setting

Introduction: Gesundes Kinzigtal offers a broad range of activities and services within their integrated care model for all ages in the region. These are for example lecture series or seminars about health topics, nutrition consultation, education programes, training courses for different needs of activity, equipment training. Since the start of Gesundes Kinzigtal 2006 those services were composed into special care programes covering different chronic diseases. Starting point for these care programes is the physician´s practice, who enrols the patient and initiates care pathway including rigid procedure structure. Practice change, theory, current status and timeline: Providing the right care at the right time and a continuous improvement of care services are guiding principles of the GK model, which is about empowerment and vertical and horizontal integration of the healthcare services. Mainly huge workload for practice staff in the enrolling procedure as well as patient´s wish being more empowered was reason of developing a new care approach named “My Health” in the beginning of 2016. Final Implementation for region Kinzigtal is planned during 2017. The overall aim of “MY Health” lies in the ability to adapt the existing programmes to the specific needs, wishes of people living in Kinzigtal region and get much closer to the subject of multi-morbidity. With regard to the new developments Gesundes Kinzigtal is about breaking down the rigid structures of the programmes and to give the patient the opportunity to individually put its elements of former programmes together. These kind of modules are very clear topics, such as medicine, therapy, medication, exercise, relaxation. Every module has a huge bunch of health offers that could be either a training module, a self-management module, a psychotherapeutic brief intervention or a particular module where the physician assistant regularly. To handle this procedure a new profession called “Consultant – My Health” will be responsible for the consultation and planning of those individual offers. All the physician practice has to do is to prescribe the consultation with his recommended modules and makes an appointment for their patients. The consultation takes place in during define opening hours at different locations (office Gesundes Kinzigtal, citizen office, practice) with respect to multi-morbid persons with limited mobility. Innovativeness, impacts, sustainability, and transferability: Within the scope of the planned care approach “My Health” the introduction of a new professions lowers the barriers for patients to enter in health activities and improves cost effectiveness of the integrated care model in the long term. Tasks of this new profession, which doesn´t exists so far in the german health care system will incorporate mainly the arrangement of the new care modules and health care services based on physician´s recommendation and the individual preferences of the patient. The physicians can be relieved from their burocratic workload for enrolment and giving detailed information about care services. But still they are up to date of the care treatment process by looking in to their electronic patient record, where the consultant puts the results that were agreed with the patient directly after the consultation appointment. Consultants will be qualified and trained to be prepared for this kind of tasks. But there is no need for extensive medical knowledge because ultimately the direction is already determined by the physician and by the modules and contraindications. Therefore, this approach can be easily transferred to other regions in Germany. My Health is currently tested in 7 GP practices and provides relevant lessons to optimize the approach and the transferability.

In silico identification of novel antagonists and binding insights by structural and functional analyses of guanylate kinase of Leishmania donovani and interaction with inhibitors

Guanylate kinase (GK; EC 2.7.4.8) is an important enzyme which catalyzed the ATP-dependent phosphorylation of GMP (guanosine monophosphate) into GDP (guanosine diphosphate) for survival of parasites; this suggests that it is a good target for design inhibitor(s). Knowledge of 3D structure of GKLdv is essential for elucidating interaction studies with the inhibitors and compared with substrate binding pattern in both the built model and template structures. The final reliable model of GKLdv has revealed α/β type protein with a G-X2-G-X-G-K that has a catalytic conserved domain in both template and model structure. The core domain consists of a central five-stranded parallel β-sheet (β5, β6, β3 and β4) whereas model has both α1-α10 and β1-β9 and active sites consist of flexible loop (FL1 to FL3). The superimposition structure of main-chain atoms of the GK model with closely homologue of GK (1EX7, chain A), has revealed better alignment and its root mean square deviation (RMSD) (43% similarity) is 0.602Ǻ. The virtual screening result has suggested that the binding pocket interacts with 5GP (5′-guanylic acid) with exhibited higher score in both GOLD and LigandFit scores and involve in amino acid interaction (H-bonding) are Arg40, Try80, Tyr52, Ser36, Glu71, and Asp102. The reported antileishmanial diospyrin (IC₅₀-7.2μM) has also exhibited higher binding activities (Dock score - 49.314 and Fitness score - 52.69) with frequently involved amino acids are Arg45, Glu102, Tyr35, Tyr54, Ser38, Tyr82, Ile103, Asp104, Lys106, Lys18, Pro13 and Ser14. The sigma pi interaction between Ile103 with diospyrin ring has revealed greater stable complex after molecular dynamic simulation studies. The best scoring compounds need for further validation in-vitro test.

Nonlocal thermoelasticity based on nonlocal heat conduction and nonlocal elasticity

Abstract Thermoelastic analysis at micro and nano-scale is becoming important along with the miniaturization of the device and wide application of ultrafast lasers, even the novel laser burst technology, where size effect on heat conduction and elastic deformation increase and classical theory of thermoelastic coupling does not hold any more. In this work, a size-dependent thermoelastic model is established for higher order simple material by adopting both the size effect of heat conduction and elasticity with the aids of extended irreversible thermodynamics and generalized free energy. It is proven that the present model is in essence identical to the coupling of nonlocal heat conductive law (GK model) and nonlocal elastic (stress gradient) model. Also, higher order boundary conditions for stress tensor and heat flux are presented and discussed. For numerical evaluation, a bi-layered structure is considered with interfacial thermal contact resistance and elastic wave impendence incorporated. From numerical results, the effects of size-dependent characteristic lengths and material constants of each layer on the transient responses are discussed, systematically. This study is expected to be helpful for theoretical modeling of thermoelasticity at nano-scale, and may be beneficial to design of nano-sized and multi-layered devices.

Factors influencing local tumor control after Gamma Knife radiosurgery for intracranial metastases from breast cancer

Because evaluation of Gamma Knife radiosurgery (GKRS) for brain metastases (METs) has mainly been based on overall or progression-free survival rates, that is, patients’ general condition and control of the primary disease, we focused on factors influencing local tumor control after GKRS for METs from breast cancer. Data were retrospectively collected from our institution’s records of patients who had undergone GKRS twice or more for METs from breast cancer. Failed GKRS was defined as a tumor needing re-treatment by further GKRS or having already been treated by other modalities prior to later GKRS procedures. Influences of various factors on local tumor control were examined. GKRS was performed on 623 tumors in 123 sessions in 90 patients. Median follow up was 9months (range 1–41months). According to multivariate analysis, use of HER2-targeting agents, (hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.18–0.99, p=0.049), five or more lesions (HR 0.24, 95% CI 0.11–0.51, p<0.001), volume >1.2cm3 (HR 3.12, 95% CI 1.62–6.02, p<0.001), use of GK model B (HR 2.53, 95% CI 1.28–4.98, p=0.0076), and prescribed dosage ⩾18Gy (HR 0.19, 95% CI 0.01–0.51, p<0.001) were predictors of failed GKRS. Patients with METs from breast cancer with HER2-positive tumors, five or more lesions, and tumors of volume ⩽1.2cm3 are good candidates for GKRS. GK model C and Perfexion achieve better local tumor control than does GK model B. The recommended dosage is ⩾18Gy.

A Gas Kinetic Scheme for the Simulation of Compressible Multicomponent Flows

AbstractIn this paper, a gas kinetic scheme for the compressible multicomponent flows is presented by making use of two-species GK model in [A. D. Kotelnikov and D. C. Montgomery, A Kinetic Method for Computing Inhomogeneous Fluid Behavior, J. Comput. Phys. 134 (1997) 364-388]. Different from the conventional BGK model, the collisions between different species are taken into consideration. Based on the Chapman-Enskog expansion, the corresponding macroscopic equations are derived from this two-species model. Because of the relaxation terms in the governing equations, the method of operator splitting is applied. In the hyperbolic part, the integral solutions of the BGK equations are used to construct the numerical fluxes at the cell interface in the framework of finite volume method. Numerical tests are presented in this paper to validate the current approach for the compressible multicomponent flows. The theoretical analysis on the spurious oscillations at the interface is also presented.

Bank Leverage Cycles and the External Finance Premium

By combining the approaches of Gertler and Karadi (2011) and Bernanke et al. (1999), I develop a DSGE model with leverage constraints both in the banking and in the non-financial firm sector. I calibrate this full model to US data. In a world with only a monetary policy and a productivity shock, the full model matches the relative volatility of the external finance premium, while a BGG model generates too low volatility. The full model also matches the procyclicality of bank leverage, unlike the GK model. For a reasonably calibrated combination shocks to the net worth of banks and non-financial firms, the model reproduces a substantial share of the contraction (increase) of investment (the external finance premium) observed during the Great Recession.

Pricing Options on Foreign Currency with a Preset Exchange Rate

This paper presents a new option that can be used by agents for managing foreign exchange risk. Unlike the Garman Kolhagen model [1], (GK), this paper presents a new model with a preset exchange rate (PE), that allows the agent to take advantage of the his/her view on both the direction and magnitude of rate movement and as such provides this agent with more choices. The model has a provision for an automatic exchange of the payoff at a preset exchange rate, and upon expiration gives the agent the choice of keeping the payoff in the foreign currency or exchanging it back to the pricing currency. At the time of writing, the buyer selects the preset exchange rate. Depending on the value selected, the PE option’s price and payoff will be equal to, greater than or less than those of the GK model. A decision rule for choosing between the PE and GK models is developed by determining the expiration spot rate that equates the two models’ returns. The range of spot rates that makes the PE option’s return greater than the GK’s return is the PE preferred range. If the agent expects the expiration spot rate will be within the preferred range, the PE option is purchased. The size of the preferred range is a decreasing function of time to expiration, a decreasing function of spot rate volatility and an increasing function of the basis point spread between foreign and domestic interest rates.

Analysis of the wave properties of a new two-lane continuum model with the coupling effect

A multilane extension of the single-lane anisotropic continuum model (GK model) developed by Gupta and Katiyar for traffic flow is discussed with the consideration of the coupling effect between the vehicles of different lanes in the instantaneous traffic situation and the lane-changing effect. The conditions for securing the linear stability of the new model are presented. The shock and the rarefaction waves, the local cluster effect and the phase transition are investigated through simulation experiments with the new model and are found to be consistent with the diverse nonlinear dynamical phenomena observed in a real traffic flow. The analysis also focuses on empirically observed two-lane phenomena, such as lane usage inversion and the density dependence of the number of lane changes. It is shown that single-lane dynamics can be extended to multilane cases without changing the basic properties of the single-lane model. The results show that the new multilane model is capable of explaining some particular traffic phenomena and is in accordance with real traffic flow.

DENSITY WAVE IN A NEW ANISOTROPIC CONTINUUM MODEL FOR TRAFFIC FLOW

In this paper, we apply a new anisotropic continuum model proposed by Gupta and Katiyar (GK model, for short) [J. Phys. A: Math. Gen.38, 4069 (2005)] to study the density wave of traffic flow. The GK model guarantees the characteristic speeds are always less than or equal to the macroscopic flow speed and overcomes the wrong way travel problem which exists in many high-order continuum models. The stability condition of the GK model is obtained. Applying nonlinear analysis to the GK model, we can obtain the soliton, one type of local density wave, which is induced by the density fluctuation in traffic flow. The soliton wave, which is determined near the neutral stability line by the Korteweg-de Vries (KdV) equation, is discussed in great detail. The numerical results show that local cluster effects which are consistent with the diverse nonlinear phenomena observed in realistic traffic flow can be induced from the GK model.

The GK rat beta-cell: A prototype for the diseased human beta-cell in type 2 diabetes?

Increasing evidence indicates that decreased functional beta-cell mass is the hallmark of type 2 diabetes (T2D) mellitus. Nowadays, the debate focuses on the possible mechanisms responsible for abnormal islet microenvironment, decreased beta-cell number, impaired beta-cell function, and their multifactorial aetiologies. This review is aimed to illustrate to what extend the Goto-Kakizaki rat, one of the best characterized animal models of spontaneous T2D, has proved be a valuable tool offering sufficient commonalities to study these aspects. We propose that the defective beta-cell mass and function in the GK model reflect the complex interactions of multiple pathogenic players: (i) several independent loci containing genes responsible for some diabetic traits (but not decreased beta-cell mass); (ii) gestational metabolic impairment inducing an epigenetic programming of the pancreas (decreased beta-cell neogenesis and/or proliferation) which is transmitted to the next generation; and (iii) loss of beta-cell differentiation due to chronic exposure to hyperglycemia/hyperlipidemia, inflammatory mediators, oxidative stress and to perturbed islet microarchitecture.

Displacement, Asymmetric Information and Heterogeneous Human Capital

In a seminal paper Gibbons and Katz (1991; GK) develop and empirically test an asymmetric information model of the labor market. The model predicts that wage losses following displacement should be larger for layoffs than for plant closings, which was borne out by data from the Displaced Workers Survey (DWS). In this paper, we take advantage of many more years of DWS data to examine how the difference in wage losses across plant closing and layoff varies with race and gender. We find that the differences between white males and the other groups are striking and complex. The lemons effect of layoff holds for white males as in the GK model, but not for the other three demographic groups (white females, black females, and black males). These three all experience a greater decline in earnings at plant closings than at layoffs. This results from two reinforcing effects. First, plant closings have substantially more negative effects on minorities than on whites. Second, layoffs seem to have more negative consequences for white men than the other groups. These findings suggest that the GK asymmetric information model is not sufficient to explain all of the data. We augment the model with heterogeneous human capital and show that this model can explain the findings. We also provide some additional evidence suggestive that both asymmetric information and heterogeneous human capital are important. In support of both explanations, we demonstrate that the racial and gender effects are surprisingly robust to region, industry and occupation controls. To look at the asymmetric information, we make use of the Civil Rights Act of 1991 which induced employers to lay off protected workers in mass layoffs rather than fire them for cause. As a result, relative to whites, a layoff would be a more negative signal for blacks after 1991 than before. If information is important, this would in turn imply that blacks experience a relatively larger loss in earnings at layoffs after 1991 than prior; and that's what we find in the data. In addition, as further evidence for heterogeneous human capital, we document for the first time in the literature that the two types of layoffs reported in the DWS data, namely layoffs due to slack work and position abolished have very different features when compared to plant closings. Finally, we simulate our model and show that it can match the data.

More Emission Cones: Multi-frequency Simulation of the Pulse Profiles of PSR J0437-4715

Pulsar radio emission beams have been studied observationally for a long time, and the suggestion is that they consist of the so-called core and conal components. To reproduce these components is a challenge for any emission model, and that the pulse profile of pulsars changes with frequency presents even a greater challenge. Assuming a local surface magnetic structure (to produce the core or central beam) and a global dipole magnetic field (to produce the conal beams), Gil & Krawczyk (1997) applied curvature radiation to the pulse profile simulation of PSR J0437-4715 (hereafter the GK model). Here we present an alternative multi-frequency simulation of the same profiles within the framework of the Inverse Compton Scattering (ICS) model. It is obtained from our simulation (1) that besides the core, the inner cone and the outer cone, there is an outer-outer cone; (2) that the emission components of the core and cones evolve strongly with frequency. Some important differences between the ICS model and the GK model are discussed, which need to be tested by further observations.

Pathophysiological and genetic characterization of the major diabetes locus in GK rats.

Genetic studies of the type 2 diabetes-like GK rat have revealed several susceptibility loci for the compound diabetes phenotype. Congenic strains were established for Niddm1, the major quantitative trait locus (QTL) for postprandial glucose levels, by transfer of GK alleles onto the genome of the normoglycemic F344 rat. Despite the polygenic nature of diabetes in GK, the locus-specific diabetes phenotype was retained in the congenic strain Niddmla, containing a GK-derived genomic fragment of 52 cM from the Niddm1 locus. Furthermore, Niddm1 was divided into two non-overlapping loci, physically separated in the two congenic strains Niddmlb and Niddm1i with distinct metabolic phenotypes. Both strains displayed postprandial hyperglycemia and reduced insulin action in isolated adipose cells. Furthermore, Niddm1i already exhibits a pronounced in vivo insulin secretion defect at 65 days, while Niddm1b develops a relative insulin secretory defect at 95 days. This suggests that Niddm1i impairs mechanisms common to insulin secretion in pancreatic B-cells and insulin action in adipocytes. Niddm1b rats show signs of increasing insulin resistance with age associated with obesity, hyperinsulinemia, and dyslipidemia. Moreover, the data indicated nonallelic interaction (epistasis) between Niddm1b and Niddm1i on the postprandial glucose levels. These data emphasize the pathophysiological complexity of diabetes, even within an apparently single QTL, and demonstrate the potential of the GK model in transforming the multifactorial diabetes phenotype into single traits, suitable for positional cloning.