Cambridge Model Research Articles

ELASTOPLASTIC CONSTITUTIVE MODEL AND MECHANICAL BEHAVIOR OF UNSATURATED LOESS

To address the issue of the absence of a suitable loess constitutive model in the study of seismic response in loess tunnels, the elastoplastic constitutive model of unsaturated loess was established by replacing the fixed yield surface with the yield surface (i.e., the variable loading surface). This model improves the algorithm of integration since the shape and position change in the stress space due to the continuous loading of unsaturated loess after yielding. In this study, the elastoplastic constitutive model was used in isotropic compression, drained triaxial compression, and undrained triaxial compression tests. The test results were compared with the Cambridge model. The results revealed that the elastoplastic constitutive model achieved a smooth transition between elasticity and plasticity and can effectively simulate soil behavior. The numerical experiment of triaxial drainage compression conformed to the theoretical concept of the boundary surface model and provided ideal simulation properties. From the undrained dynamic triaxial compression numerical test, it was seen that the constitutive model can describe the elastoplastic deformation in the yield surface and better reflect the cyclic strength softening and cyclic stiffness degradation of soil.

Validation of prevalent diabetes risk scores based on non-invasively measured predictors in Ghanaian migrant and non-migrant populations – The RODAM study

BackgroundNon-invasive diabetes risk models are a cost-effective tool in large-scale population screening to identify those who need confirmation tests, especially in resource-limited settings. AimsThis study aimed to evaluate the ability of six non-invasive risk models (Cambridge, FINDRISC, Kuwaiti, Omani, Rotterdam, and SUNSET model) to identify screen-detected diabetes (defined by HbA1c) among Ghanaian migrants and non-migrants. Study designA multicentered cross-sectional study. MethodsThis analysis included 4843 Ghanaian migrants and non-migrants from the Research on Obesity and Diabetes among African Migrants (RODAM) Study. Model performance was assessed using the area under the receiver operating characteristic curves (AUC), Hosmer-Lemeshow statistics, and calibration plots. ResultsAll six models had acceptable discrimination (0.70 ≤ AUC <0.80) for screen-detected diabetes in the overall/combined population. Model performance did not significantly differ except for the Cambridge model, which outperformed Rotterdam and Omani models. Calibration was poor, with a consistent trend toward risk overestimation for screen-detected diabetes, but this was substantially attenuated by recalibration through adjustment of the original model intercept. ConclusionThough acceptable discrimination was observed, the original models were poorly calibrated among populations of African ancestry. Recalibration of these models among populations of African ancestry is needed before use.

Solidification Treatment of Wastewater and Waste Soil Generated during Binhai Reclamation: A Study on Mechanical Properties and Resource Utilization

Coastal reclamation projects generate an accumulation of wastewater and waste soil, resulting in highly saturated soft soil. Presently, there is a scarcity of research regarding the lightweight solidification and three-dimensional mechanical properties of these soils. Additionally, there is a dearth of specialized models for stabilizing soils containing wastewater using lightweight solidification technology, and pertinent engineering solutions are lacking. By introducing solidifying agents and foaming agents to treat wastewater in soft fill soil, a novel type of solidified lightweight material is produced, imparting strength. This study investigates its three-dimensional mechanical properties. During triaxial tests with equal stress (σ3) and equal b values, the softening of the curve noticeably diminished at b = 0.25. In the plane strain test, cohesion increased by 10.7% compared to the traditional triaxial tests, and the internal friction angle increased by 11%. Subsequently, a three-dimensional Cambridge model was established. At elevated confining pressures, the corrected curve closely approximated the test curve, demonstrating a minimum model accuracy of approximately 96% at a confining pressure of 20 KPa. These findings offer valuable numerical references and a theoretical foundation for the efficient utilization of wastewater and waste soil.

Research on the Fracture Propagation Law of Separate Layered Fracturing in Unconventional Sandstone Reservoirs

The unconsolidated sandstone is a type of rock that has poor cementation, a low strength, a high porosity, and permeability. It is highly compressible under high stress and exhibits non-linear plastic deformation during hydraulic fracturing construction in its reservoir. In this study, the mechanical properties of unconsolidated sandstone with a different permeability were studied, and a three-dimensional hydraulic fracture propagation numerical model was established based on the modified traditional Cambridge model. This model was used to simulate the fracture propagation law of unconsolidated sandstone in separate layer fracturing under different construction conditions. During hydraulic fracturing construction, the fracturing fluid slowly invades the reservoir when the displacement of the fracturing fluid is small. The unconsolidated sandstone undergoes compaction and hardening, followed by shear expansion, and then complete destruction. A larger displacement will cause the reservoir rock to directly enter the state of destruction from compaction and hardening. This study found that several critical parameters are obtained for fracturing construction. When the displacement is greater than 5 m3/min, the fracturing fluid exceeds 100 mPa·s, or when the filtration coefficient exceeds 1.2 × 10−3 m/s, the second and third layers will be penetrated. This study provides valuable insights into the mechanical properties of unconsolidated sandstone and reveals the critical parameters for the successful hydraulic fracturing construction in this type of reservoir.

CatBoost–Bayesian Hybrid Model Adaptively Coupled with Modified Theoretical Equations for Estimating the Undrained Shear Strength of Clay

The undrained shear strength of clay is an important index for the calculation of the bearing capacity of the foundation soil, the calculation of the soil pressure of the foundation pit, and the analysis of the slope stability. Therefore, the purpose of this paper is to conduct a comprehensive study of the combined use of machine learning with clay theoretical equations to estimate it. Under the Bayesian framework, the CatBoost algorithm (CatBoost–Bayesian) based on Bayesian optimization algorithm was developed to obtain the feature importance level of soil parameters affecting the undrained shear strength of clay, so as to adaptively couple the theoretical equation of undrained shear strength of K0 consolidated clay, which was derived from the modified Cambridge model. Then, the theoretical equation of undrained shear strength of the isotropically consolidated clay was established from the critical state of the clay parameters. Finally, it was illustrated and verified using the experimental samples of Finnish clay. The results indicate that the theoretical equation established by the overconsolidation ratio and effective overburden pressure parameters can well estimate the undrained shear strength of isotropically consolidated clays, and the parameter uncertainty can be considered explicitly and rigorously.

Analyses on face stability of shallow tunnel considering different constitutive models

Based on the finite element limit analysis method, the stability of the face in case of active failure under three constitutive models, the Mohr-Coulomb model (MC), the modified Cambridge model (MCC) and the Drucker-Prager model (DP), were analyzed. The ultimate support pressure of the face and the influence of factors such as different burial depth ratios (C/D), cohesion (c) and friction angle (φ) in the MC model are also discussed. The results show that the safety factor obtained by the MCC model under the same support pressure is always smaller than that of the MC model, and the difference is the largest when there is no support pressure. As the support pressure increases, it will gradually approach the MC model. When the support pressure is small, the safety factor obtained by the DP model is larger than the MC model, but when the support pressure is large, it is smaller than the MC model, and the final difference tends to be stable. It is necessary to select an appropriate constitutive model according to different rock masses in practical engineering. The self-stabilizing performance of the face is not affected by C/D, and the ultimate support pressure will increase with the increase of C/D, decrease linearly with the increase of cohesion, and decrease with the increase of friction angle. When the friction angle is small, the ultimate support pressure is greatly affected by C/D, and when the friction angle is large, it is hardly affected by C/D.

POZİTİF SENTİNEL LENF DÜĞÜMÜ OLAN MEME KANSERLİ HASTALARDA TAMAMLAYICI AKSİLLER DİSEKSIYON GEREKLİLİĞİNİN NOMOGRAM YÖNTEMLERİNİN DEĞERLENDİRİLMESİYLE BELİRLENMESİ

AIM: Our aim was to evaluate the efficacies of different nomogram approaches, including the Memorial Sloan Kettering Cancer Centre (MSKCC), Stanford University, Tenon Hospital, Cambridge University and TR methods, in patients operated for breast cancer.&#x0D; MATERIAL AND METHOD: The study included 60 breast cancer patients who were operated on for breast cancer at Ankara Numune Training and Research Hospital, A2 General Surgery Clinic, between 2007 and 2012. All patients were sentinel lymph node (SLN)-positive and had undergone axillary lymph node dissection (ALND). Five different scoring systems were applied retrospectively to these 60 patients. Receiver operating characteristics (ROC) curves were created for the nomograms and the area under the curve (AUC) sensitivity and specificity results were calculated.&#x0D; RESULTS: Twenty-two patients (37%) had axillary non-SLN metastases. AUC values of MSKCC, Stanford, Cambridge, Tenon and TR nomogram were calculated as 0.646, 0.644, 0.62, 0.595, and 0.66, respectively. A significant difference was found between the groups with and without non-SLN metastasis in terms of SLN metastasis size (p = 0.013).&#x0D; CONCLUSION: The MSKCC, Stanford, Cambridge, Tenon, and TR nomogram models were found to have insufficient power to discriminate between patients with and without non-SLN metastases in patients with SLN-positive breast cancer (AUC values

Research on Fuzzy Plastic Constitutive Model Based on Membership Function

Soil has no obvious yield point, and the classical elastoplastic theory contradicts the uncertainty of the plastic yield point of the soil. Therefore, a fuzzy plastic Cambridge model based on the membership function was designed by combining the fuzzy mathematics with the Cambridge model. This model made the plastic membership function to correspond with the fuzzy yield function. The plastic strain at any stress state was calculated using the fuzzy Cambridge model and was compared with the indoor triaxial test results, and they were in good agreement. Therefore, it is appropriate to use fuzzy mathematics to express the unobvious soil yield property. The characteristics of soil yield in any stress state is reflected by the fuzzy plastic theory, which indicates that there is entirely no elasticity at any stress state. Moreover, the varying degrees of plasticity and the degree of plastic yield were uniquely determined by the plastic membership function. The fuzzy plastic model used the membership function change to replace the complex hardening. Additionally, the cyclic loading path was clear and appropriate for the cyclic loading and unloading calculations.

Fuzzy Plastic Constitutive Model and Its Application to Subgrade

The subgrade of a road is subjected to cyclic loading and unloading under the action of traffic loads. To study this mechanical response, the plastic membership function was introduced into the modified Cambridge model, and thus, the fuzzy plastic Cambridge constitutive model was obtained. With the continuous evolution of the plastic membership function from 0 to 1, the fuzzy plastic Cambridge constitutive model continuously transitions the plastic properties inside and outside the initial yield surface. The evolution of the plastic membership function can replace the complex hardening law. The reliability of the model was verified using triaxial tests and simple cyclic loading and unloading tests. Using the finite element method, the mechanical response of the subgrade under cyclic loading was calculated. The fuzzy plastic Cambridge model can explain the insignificant yield characteristics of geotechnical media. In the fuzzy plasticity theory, the stress inside and outside the initial yield surface can produce plasticity. Absolute plasticity was not observed; only different degrees of plasticity existed.

Numerical Analysis of the Preloading Consolidation of the Soft Foundation with a Plastic Drainage Plate

The permeability coefficient and void ratio are related to the stress state of the soil, which manifests as the temporal and spatial variability of consolidation. Based on the modified Cambridge model, this paper quotes the functional relationship between the soil permeability coefficient and void ratio and soil stress obtained by Tylor’s research and then uses finite-element software ABAQUS and its secondary development platform to establish a plastic drainage plate surcharge preloading numerical model that considers the influence of the void ratio and permeability coefficient with stress changes. The results show that considering the variability of the permeability coefficient in the consolidation process of the soft foundation has a great influence on the change of the consolidation state but has a small effect on the final consolidation state. For soft foundation surcharge preloading reinforcement treatment, if the strength of the soft foundation is low but the surcharge is large, the geometric nonlinearity and material nonlinearity should be considered. Using the theory of large deformation consolidation to calculate the consolidation of soil is closer to the actual situation.

214-OR: Cambridge Hybrid Closed-Loop in Children and Adolescents with T1D: A Multicentre Six-Month Randomised Trial

Aims: We assessed safety and efficacy of Cambridge hybrid closed-loop (HCL) compared with usual care over 6 months in children and young people with T1D. Methods: In an open-label multicentre multinational parallel randomised controlled trial, we randomly assigned participants on insulin pump therapy aged 6 to 18 years to receive either HCL therapy (CL) or continue usual care (control) for 6 months. We used the same Cambridge model predictive control algorithm in two consecutive hardware iterations, FlorenceM then CamAPS FX. Primary endpoint was central laboratory HbA1c at 6 months. Results: We randomised 133 participants: 65 to CL and 68 to control (baseline HbA1c 8.2±0.7% vs. 8.3±0.8%). At 6 months mean HbA1c was 0.32% lower in CL compared to control (95% CI -0.59 to -0.04; p=0.02). Closed-loop usage was low (40% [26, 53]; median [IQR]) with FlorenceM due to hardware issues, and high (93% [88, 96]) with CamAPS FX. In the CamAPS FX CL group (n=21) HbA1c was 1.05% lower (95% CI -1.43 to -0.67; p Conclusion: Cambridge HCL is safe and significantly improves glycaemic control in children and young people with T1D. Efficacy relies on consistent usage of closed-loop, as demonstrated by CamAPS FX. Disclosure J. Fuchs: None. B. A. Buckingham: Advisory Panel; Self; Medtronic, Tolerion, Inc., Research Support; Self; Beta Bionics, Inc., Insulet Corporation, Medtronic, Tandem Diabetes Care. N. Davis: None. L. Dimeglio: Advisory Panel; Self; MannKind Corporation. N. Mauras: Advisory Panel; Self; Novo Nordisk, Research Support; Self; LifeScan, Medtronic, Novo Nordisk. R. Besser: None. A. Ghatak: None. S. A. Weinzimer: Advisory Panel; Self; Dompe, Zealand Pharma A/S, Speaker’s Bureau; Self; Medtronic. K. K. Hood: Consultant; Self; Cecelia Health, Cercacor, LifeScan Diabetes Institute. D. Fox: None. L. Kanapka: None. C. K. Boughton: None. C. Kollman: Consultant; Self; Diasome Pharmaceuticals, Inc., Research Support; Self; Dexcom, Inc., Tandem Diabetes Care. J. Sibayan: None. R. Beck: Consultant; Self; Bigfoot Biomedical, Inc., Diasome Pharmaceuticals, Inc., Insulet Corporation, Lilly Diabetes, vTv Therapeutics, Research Support; Self; Beta Bionics, Inc., Dexcom, Inc., Medtronic, Novo Nordisk, Tandem Diabetes Care. R. Hovorka: Research Support; Self; Abbott Laboratories, Dexcom, Inc., Medtronic, Speaker’s Bureau; Self; Dexcom, Inc., Eli Lilly and Company, Stock/Shareholder; Self; CamDiab Ltd. Dan05 consortium: n/a. J. M. Allen: None. M. E. Wilinska: Consultant; Self; CamDiab Ltd. M. Tauschmann: None. L. Denvir: None. A. Thankamony: None. F. Campbell: n/a. R. Wadwa: Consultant; Self; Tandem Diabetes Care, Research Support; Self; Dexcom, Inc., Eli Lilly and Company, Tandem Diabetes Care. Funding National Institute of Diabetes and Digestive and Kidney Diseases (UC4DK108520)

Symptom Descriptions in Psychopathology: How Well Are They Working for Us?

In this article, we examine how symptoms are conceptualized in theories of psychopathology. We identify five questions that need to be asked about symptoms, including what kind of constructs they are, how we should describe them, and what causal explanations they support. We then examine how three different theoretical frameworks address these questions: the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, the symptom-network-modeling approach, and the Cambridge model of symptom formation. We show that the assumptions these frameworks make affect the kinds of theoretical models they support and the research approaches they advocate. When symptoms are viewed as empirical observations, the focus of inquiry is directed elsewhere. However, when symptoms are understood as complex constructs in their own right, that are themselves built on certain theoretical assumptions, then understanding them becomes crucial to theoretical progress. We conclude by calling for greater focus on research that unpacks the constructs underlying symptoms.

Alternative Models of Psychopathology: The Diagnostic and Statistical Manual of Mental Disorders, the Hierarchical Taxonomy of Psychopathology, Research Domain Criteria, Network Analysis, the Cambridge Model, and the Five-Factor Model

Wilshire, Ward, and Clark (this issue, p. 323) critiqued the classification of psychopathology in the Diagnostic and Statistical Manual of Mental Disorders, offering as an alternative a “Cambridge model” that focuses on symptoms rather than syndromes. They compared their model with additional alternatives, such as the Research Domain Criteria, the Hierarchical Taxonomy of Psychopathology, and network analysis. In this commentary, I offer further comparisons, considering as well the five-factor model alternative to the DSM syndromal classification of personality disorder.

Hybrid closed-loop glucose control with faster insulin aspart compared with standard insulin aspart in adults with type 1 diabetes: A double-blind, multicentre, multinational, randomized, crossover study.

To evaluate the use of hybrid closed-loop glucose control with faster-acting insulin aspart (Fiasp) in adults with type 1 diabetes (T1D). In a double-blind, multinational, randomized, crossover study, 25 adults with T1D using insulin pump therapy (mean ± SD, age 38 ± 9 years, HbA1c 7.4% ± 0.8% [57 ± 8 mmol/mol]) underwent two 8-week periods of unrestricted living comparing hybrid closed-loop with Fiasp and hybrid closed-loop with standard insulin aspart in random order. During both interventions the CamAPS FX closed-loop system incorporating the Cambridge model predictive control algorithm was used. In an intention-to-treat analysis, the proportion of time sensor glucose was in the target range (3.9-10.0 mmol/L; primary endpoint) was not different between interventions (75% ± 8% vs. 75% ± 8% for hybrid closed-loop with Fiasp vs. hybrid closed-loop with standard insulin aspart; mean-adjusted difference -0.6% [95% CI -1.8% to 0.7%]; p < .001 for non-inferiority [non-inferiority margin 5%]). The proportion of time with sensor glucose less than 3.9 mmol/L (median [IQR] 2.4% [1.2%-3.2%] vs. 2.9% [1.7%-4.0%]; p = .01) and less than 3.0 mmol/L (median [IQR] 0.4% [0.2%-0.7%] vs. 0.7% [0.2%-0.9%]; p = .03) was reduced with Fiasp versus standard insulin aspart. There was no difference in mean glucose (8.1 ± 0.8 vs. 8.0 ± 0.8 mmol/L; p = .13) or glucose variability (SD of sensor glucose 2.9 ± 0.5 vs. 2.9 ± 0.5 mmol/L; p = .90). Total daily insulin requirements did not differ (49 ± 15 vs. 49 ± 15 units/day; p = .45). No severe hypoglycaemia or ketoacidosis occurred. The use of Fiasp in the CamAPS FX closed-loop system may reduce hypoglycaemia without compromising glucose control compared with standard insulin aspart in adults with T1D.

Triple-Shear Elastoplastic Constitutive Models for Normally Consolidated Unsaturated Soils Based on the Coordinate Translation Method

The unified triple-shear strength criterion for unsaturated soils was established with the single-stress variable method and the double-stress variable method, and the corresponding triple-shear failure stress ratios were derived with the coordinate translation method. Then the triple-shear failure stress ratios were combined with the modified Cambridge model for unsaturated soils, the triple-shear elastoplastic constitutive models for normally consolidated unsaturated soils under the single-stress variable and double-stress variable were built, and the secondary development of ABAQUS was carried out. With the Nanchang unsaturated remolded clay as the research object, the consolidation and drainage (CD) test verification and true triaxial CD test simulation of unsaturated soils were done, and the effects of intermediate principal stress influence coefficient b and matrix suction s on the calculation model for the gravity retaining wall were studied. The results show that, the proposed 2 constitutive models can well describe the deformation characteristics of normally consolidated unsaturated soils in CD tests, and the simulation results of the coordinate translation method under double-stress variables are more close to the real test data. In the simulation of true triaxial CD tests, the shear stress and the volume strain obtained with the double-stress variable method are more close to the results of the single-stress variable method. With the increase of intermediate principal stress influence coefficient b, the shear stress and the volume strain of the 2 constitutive models will also increase. The gravity retaining wall calculation model with the double-stress variable method is more stable. With the increase of intermediate principal stress influence coefficient b or matrix suction s, the soil displacement of the retaining wall model will decrease, while the strength and stability of the soils behind the wall will increase.

O SUPERMULTIPLICADOR SRAFFIANO, A INSTABILIDADE FUNDAMENTAL DE HARROD E O DILEMA DE “OXBRIDGE”

O trabalho compara o modelo de crescimento liderado pela demanda do supermultiplicadorsraffiano com os principais modelos de crescimento pós-keynesianos,usando um esquema analítico simples. Demonstramos que: o modelo permite o ajustamentoda capacidade à tendência da demanda, em contraste com o modelo de Harrod;que nos modelos de Cambridge há a tendência oposta de ajustamento da demanda àcapacidade produtiva; e que o supermultiplicador mantém a hipótese de distribuiçãoexógena, mas sem a necessidade de ter que supor que o grau efetivo de utilização dacapacidade é endógeno, como nos modelos baseados em Kalecki e Steindl.

Elastoplastic Model and Three-Dimensional Method for Unsaturated Soils

This paper proposed a new elastoplastic constitutive model to predict the deformation and strength behaviour of unsaturated soils. Applying the modified Cambridge model as a generalization, the degree of saturation is introduced into the elastoplastic model of unsaturated soil. Under the condition of ensuring that the model parameters are unchanged, the model is transformed into three dimensions based on the SMP criterion transformation stress method. Enhanced modified van Genuchten model under true triaxial conditions is also proposed in this paper to describe hydromechanical behaviours of unsaturated soils. The proposed constitutive model can capture the observed mechanical and hydraulic behaviours. Then, the model is validated via equal p and equal b value true triaxial tests, and the results show that a reasonable agreement can be obtained.

Underpinning of the sharing knowledge about immunisation (SKAI) communication approach: A qualitative study using recorded observations

ObjectiveTo refine communication strategies to assist clinician conversations with vaccine hesitant and declining parents as part of the Sharing Knowledge About Immunisation (SKAI) package. MethodsWe recorded and analysed consultations held in two Specialist Immunisation Clinics in tertiary hospitals in Australia between consenting clinicians and parents. We undertook content analysis that was both iterative and informed by the Calgary Cambridge Model of health communication and motivational interviewing. ResultsWe found common strengths and opportunities in clinician's communication styles. Strengths included: rapport building; communicating care for both the parent and child; exhibiting depth of vaccination-specific communication skill and content knowledge. Opportunities for strengthening communication practices included: eliciting parents' concerns to saturation early in the consultation; structuring the consultation to prioritise and address parents' concerns; recognising and responding to parents' motivation to vaccinate; effectively closing consultations. ConclusionThis study has synthesised clinical communication strategies from expert vaccination communicators using well-established communication frameworks to advance a unique approach to the challenging task of addressing vaccine hesitancy and refusal. Practice implicationsThe clinic observations helped us to create a structured consultation guide that can enhance and provide greater structure to a clinician's existing communication skills.

Effects of overconsolidation ratio on undrained shear strength of clay considering pressuremeter of limited length: cases study

Undrained shear strength (Su) of foundation soils were estimated from the results of pressuremeter tests conducted on slightly overconsolidated and overconsolidated clays in two test sites. To investigate the effects of overconsolidation ratio (OCR) and pressuremeter of limited length on the undrained shear strength of clays, three kinds of evaluation methods based on the cavity expansion theory were used in this study.Where the direct traditional method suggested by Gibson and Anderson ignores the effect of pressuremeter of limited length and OCR, the analytic method based on modified Cambridge model proposed by Cao only considers the effect of OCR, the finite element method (FEM) in view of the modified Cambridge model take the effects both of pressuremeter of limited length and OCR into account. The results show that the undrained shear strength obtained from the direct traditional method is significantly smaller than that obtained from the analytic method due to the effect of OCR, and with the increase of OCR, the difference between the two increases. The undrained shear strength estimated from the analytical method is larger than that estimated from the FEM in virtue of the effect of pressuremeter of umlimited length, and with the increase in OCR, the effect of pressuremeter of limited length rapidly decreased.When performing a PMT in clay with pressuremeter of limited length, there is a critical value of OCR, where the length effect is higher than the OCR effect when the OCR is below this critical value, while the effect of OCR and the length cancel each other out when the OCR is above this critical value. The threshold value is predicted to be 23 for the OC silty clay in case 1,and the actual value of the threshold is 34 for the OC silty clay in case 2.

Unemployment and Growth: Putting Unemployment into Post Keynesian Growth Theory

ABSTRACTPost Keynesian (PK) growth models typically fail to model unemployment. That shows up in the absence of an equilibrium condition requiring the growth of employment to equal labor-supply growth. Consequently, the models can have an imploding or exploding unemployment rate. The underlying analytical problem is failure to resolve the Harrod (1939)–Solow (1956) knife-edge problem. This paper shows how that knife-edge problem can be resolved via a Kaldor–Hicks technological progress function. It applies the concept to several different PK growth models. In the Harrod, super-multiplier, Cambridge, and neo-Kaleckian models the warranted rate rules the roost and natural rate forces have no impact on the equilibrium growth rate. However, in a modified neo-Kaleckian model, with labor market distribution conflict, both warranted rate and natural rate forces impact steady state growth.