Humanoid robots are highly redundant, and finding whole-body optimal trajectories for various tasks is very complex. This paper proposes a method to find an energy-optimal, dynamically balanced, and collision-free trajectory of the 20 degrees of freedom humanoid robot in pick and place application. The task of pick and place is divided into three subtasks using the Pseudoinverse Jacobian method of redundancy resolution. The three subtasks are end effector trajectory represented by $\mathcal {T}_1$, hip trajectory represented by $\mathcal {T}_2$, and maximizing the manipulability represented by $\mathcal {T}_3$. The Pseudoinverse Jacobian method is coupled with particle swarm optimization (PSO) to find the optimal trajectories. The main contribution of this paper is the decomposition of the whole-body task of the humanoid robot into three distinct subtasks to find energy-optimal, dynamically balanced, and obstacle-free trajectories. The concept of virtual surface is used to avoid dragging objects on the table surface. The problem is optimized with Particle Swarm Optimization. Simulations were conducted to pick up and place objects from a table and constrained spaces like a drawer. The results show that the robot can pick and place objects from defined locations on the table.

A decisive voter’s exact ideological preferences can be hard to predict, even for seasoned candidates. We develop a novel theory of electoral competition where candidates are evaluated on ideological and nonideological dimensions. The key feature of our theory is that an electorate’s partisan leaning serves as a signal of the median voter’s ideological position where extreme leanings are more informative about voters than centrist leanings. We show that this leads to an endogenous sorting of districts between “extreme” and “centrist” and that an increase in the importance of candidate competence for voters increases polarization—but only in extreme districts. We evaluate our theory using data from mayoral elections in Brazil’s 95 largest municipalities and exploit COVID-19 as a shock to the salience of candidate competence. We show that COVID-19 increases the salience of competence in these elections, leading to increased political polarization, which is concentrated in cities with extreme partisan leanings.

While reformulation policies are commonly used to incentivise manufacturers to improve the nutrient profile of the foods and beverages they produce, only a few countries have implemented mandatory reformulation policies. This paper aimed to review evidence on the design, implementation challenges and effectiveness of mandatory reformulation policies and compare them to voluntary reformulation policies. The systematic search retrieved seventy-one studies including twelve on mandatory reformulation policies. Most mandatory reformulation policies were aimed at reducing trans-fatty acids or sodium in foods. Overall, mandatory reformulation policies were found to be more effective than voluntary ones in improving dietary intakes. Mandatory policies were implemented when voluntary policies either failed or were found to be insufficient to improve the composition of foods. Typical features of mandatory policies could also improve the design of voluntary policies. Examples include strict but attainable targets and a tight monitoring of compliance.

In this paper, we propose a hybrid sparse array design utilizing Delaunay Triangulation algorithm for element positioning and Convex algorithm for element excitation optimization. This Delaunay Triangulation algorithm yields a radiation pattern devoid of grating lobes. Then Convex algorithm is used to optimize the element excitations to further decrease side-lobe-level. The minimum inter-element distance is as large as 8 times of wavelength. The peak-side-lobe-level can be −17.3 dB. Furthermore, beam steering can be achieved with good performance within 80° field-of-view range.

This article documents a trend of declining flexibility in share repurchase policies over the last 4 decades. We show that repurchases have become particularly sticky for firms with repurchase programs in place. We also exploit the additional inflexibility within existing repurchase programs to show that repurchase stickiness can have real effects for firms. Using the 2008 financial crisis as a shock to firms’ ability to raise capital, we find that firms with ongoing share repurchase programs ending after Dec. 2007 reduced investment, employment, and R&D spending by more than similar firms with programs ending before the onset of the crisis.

Founded a century ago upon the initiative of three European men, each with links to colonial administration or mission, the International African Institute subsequently developed in directions that could hardly have been predicted. Most of those directly involved in the first two decades were from Belgium, Britain, France, Germany, Italy and Switzerland, including a growing number of academics. In addition to promoting creative writing in Africa and a common orthography for African languages, the Institute secured private American funding for a big research programme involving social anthropological fieldwork. After 1945, with decolonization on the horizon, the focus was on systematically producing ethnographic and linguistic handbooks. From the 1960s onwards the Institute endeavoured to shake off its remaining links to colonialism and – to a modest degree – to africanize itself. Its successes lay in organizing a series of International African Seminars, held at newly emerging African universities, and in continuing to produce the journal Africa, as well as several series of monographs.

The marketing of unhealthy foods has been implicated in poor diet and rising levels of obesity. Rapid developments in the digital food marketing ecosystem and associated research mean that contemporary review of the evidence is warranted. This preregistered (CRD420212337091)1 systematic review and meta-analysis aimed to provide an updated synthesis of the evidence for behavioural and health impacts of food marketing on both children and adults, using the 4Ps framework (Promotion, Product, Price, Place). Ten databases were searched from 2014 to 2021 for primary data articles of quantitative or mixed design, reporting on one or more outcome of interest following food marketing exposure compared with a relevant control. Reviews, abstracts, letters/editorials and qualitative studies were excluded. Eighty-two studies were included in the narrative review and twenty-three in the meta-analyses. Study quality (RoB2/Newcastle–Ottawa scale) was mixed. Studies examined ‘promotion’ (n 55), ‘product’ (n 17), ‘price’ (n 15) and ‘place’ (n 2) (some > 1 category). There is evidence of impacts of food marketing in multiple media and settings on outcomes, including increased purchase intention, purchase requests, purchase, preference, choice, and consumption in children and adults. Meta-analysis demonstrated a significant impact of food marketing on increased choice of unhealthy foods (OR = 2·45 (95 % CI 1·41, 4·27), Z = 3·18, P = 0·002, I2 = 93·1 %) and increased food consumption (standardised mean difference = 0·311 (95 % CI 0·185, 0·437), Z = 4·83, P < 0·001, I2 = 53·0 %). Evidence gaps were identified for the impact of brand-only and outdoor streetscape food marketing, and for data on the extent to which food marketing may contribute to health inequalities which, if available, would support UK and international public health policy development.

This article provides the first comprehensive evidence that the return extrapolation behavior of investors leads to biases in the expectations of volatility. Lower past returns are associated with higher expectations of volatility when using the physical, risk-neutral, and survey measures to estimate volatility expectations. Consistent with the return extrapolation framework, recent past returns have a larger impact than distant past returns on volatility expectations. Biases in volatility expectations are i) distinct from extrapolating past realized volatility, ii) asymmetrically induced by recent past negative returns, and iii) lead investors to pay more to insure against the perceived higher expected volatility.

We show theoretically and empirically that the cross-section of stock return idiosyncratic volatilities contains useful information about the ICAPM. We construct a proxy cross-sectional bivariate idiosyncratic volatility (CBIV) for the covariance risk between the market and the unobserved hedge portfolio under the ICAPM. Consistent with the ICAPM pricing relation, CBIV is a robust and significant predictor of the equity risk premium. We further show that the return predictability of the tail index in Kelly and Jiang (2014) can be explained by the ICAPM covariance risk.

Collaborative robotics in manufacturing introduces a new era of seamless human–robot collaboration (HRC), enhancing production line efficiency and adaptability. However, guaranteeing safe interaction while maintaining performance objectives presents significant challenges. Integrating safety with optimal robot performance is paramount to minimize task time and ensure its completion. Our work introduces an architecture for safety in confined human–robot workspaces by integrating existing safety and productivity methods into a unified framework specifically designed for constrained environments. By employing an improved artificial potential field, we optimize paths based on length and bending energy and compare baseline algorithms like gradient descent algorithm and rapidly exploring random tree (RRT*). We propose an evaluation metric for system performance that objectively maps to the system’s safety and efficiency in diverse collaborative scenarios. Additionally, the architecture supports multimodal interaction, including gesture-based inputs, for intuitive control and improved operator experience. Safety measures address static and dynamic obstacles using potential fields and safety zones, with a real-time safety evaluation module adjusting trajectories under specified constraints. A performance recovery algorithm facilitates swift resumption of high-speed operations post safety interventions. Validation includes comparing the algorithmic performance through simulations and experiments using the 6-degrees of freedom UR5 robot by universal robots to identify the most suitable algorithm. Results demonstrate an 83.87% improvement in system performance compared to ideal case scenarios, validating the effectiveness of the proposed architecture, evaluation metric, and multimodal interaction in enhancing safety and productivity.