The magic of the Last Planner® System for Nigerian construction

Extremely poor economic performance of the Nigerian construction industry suggests that non-value adding activities are prevalent, which result not only in the reduction of contractors’ profit margin but economic loss for the country in general. This study analyses non-value adding activities in Nigerian construction sites. The research seeks to establish potential antidotes within the Last Planner® System (LPS) and reveal the elements of the LPS which could be abstracted into Nigerian construction to improve performance. It was found that these elements form the theoretical basis for developing a lean approach that was labelled Last Planner® thinking

Gasoline prices jump up on Mondays: An outcome of aggressive competition?

This paper examines Norwegian gasoline pump prices using daily station-specific observations from March 2003 to March 2006. Whereas studies that have analyzed similar price cycles in other countries find support for the Edgeworth cycle theory (Maskin and Tirole, 1988), we demonstrate that Norwegian gasoline price cycles involve a form of coordinated behavior. Retail gasoline prices follow a fixed weekly pattern, where retail outlets all over Norway simultaneously increase their prices to the same level every Monday at noon. Consequently, the sharp price increase is tied to time rather than the current price level. The gasoline companies’ headquarters publish a recommended price that de facto is a RPM arrangement towards the retail outlets. The vertical arrangement is industry-wide adopted, and is used to coordinate the time and the level for retail price increases among the big four gasoline companies. Monday changed from being the low-price day to becoming the high-price day almost ‘overnight’ in April 2004, and we empirically establish that the change corresponds to a significant jump in the gross margin.Gasoline Prices; Resale Price Maintenance

Evolved embodied phase coordination enables robust quadruped robot locomotion

Overcoming robotics challenges in the real world requires resilient control systems capable of handling a multitude of environments and unforeseen events. Evolutionary optimization using simulations is a promising way to automatically design such control systems, however, if the disparity between simulation and the real world becomes too large, the optimization process may result in dysfunctional real-world behaviors. In this paper, we address this challenge by considering embodied phase coordination in the evolutionary optimization of a quadruped robot controller based on central pattern generators. With this method, leg phases, and indirectly also inter-leg coordination, are influenced by sensor feedback.By comparing two very similar control systems we gain insight into how the sensory feedback approach affects the evolved parameters of the control system, and how the performances differs in simulation, in transferal to the real world, and to different real-world environments. We show that evolution enables the design of a control system with embodied phase coordination which is more complex than previously seen approaches, and that this system is capable of controlling a real-world multi-jointed quadruped robot.The approach reduces the performance discrepancy between simulation and the real world, and displays robustness towards new environments.Comment: 9 page

Competing conventions: The Big Branders’ struggle to incorporate new quality conceptions in the Norwegian food market

The paper addresses recent changes in the Norwegian agrifood industry from the analytical perspective of quality conventions. Storper and Salais’ “worlds of production” plus Boltanski and Thévenots’ “orders of worth” are used as a basis for the empirical study. First, the paper discusses how the largest Norwegian branders try to strategically adapt to “novel” quality attributes like health-enhancing food, origin/terroir, environmental sustainability and ethics. Second, the paper investigates the companies’ quality signalling strategy: How are these “novel” qualities communicated to consumers? Multiple options are available: Do they attempt to systematically incorporate “novel qualities” into their private brand equity (“conventionalizing qualities”)? Do they prefer a co-labelling scheme with a third party control, or do they use any other measures for quality signalling? The paper thereby discusses how the largest Norwegian branders in the food sector cope with conflicting and competing quality conventions.Food quality, economics of convention., Food Consumption/Nutrition/Food Safety,

Arctic air pollution: Challenges and opportunities for the next decade

The Arctic is a sentinel of global change. This region is influenced by multiple physical and socio-economic drivers and feedbacks, impacting both the natural and human environment. Air pollution is one such driver that impacts Arctic climate change, ecosystems and health but significant uncertainties still surround quantification of these effects. Arctic air pollution includes harmful trace gases (e.g. tropospheric ozone) and particles (e.g. black carbon, sulphate) and toxic substances (e.g. polycyclic aromatic hydrocarbons) that can be transported to the Arctic from emission sources located far outside the region, or emitted within the Arctic from activities including shipping, power production, and other industrial activities. This paper qualitatively summarizes the complex science issues motivating the creation of a new international initiative, PACES (air Pollution in the Arctic: Climate, Environment and Societies). Approaches for coordinated, international and interdisciplinary research on this topic are described with the goal to improve predictive capability via new understanding about sources, processes, feedbacks and impacts of Arctic air pollution. Overarching research actions are outlined, in which we describe our recommendations for 1) the development of trans-disciplinary approaches combining social and economic research with investigation of the chemical and physical aspects of Arctic air pollution; 2) increasing the quality and quantity of observations in the Arctic using long-term monitoring and intensive field studies, both at the surface and throughout the troposphere; and 3) developing improved predictive capability across a range of spatial and temporal scales

The Critical Role of Public Charging Infrastructure

Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change

Collective action of water molecules in zeolite dealumination

When exposed to steam, zeolite catalysts are irreversibly deactivated by loss of acidity and framework degradation caused by dealumination. Steaming typically occurs at elevated temperatures, making it challenging to investigate the mechanism with most approaches. Herein, we follow the dynamics of zeolite dealumination in situ, in the presence of a realistic loading of water molecules by means of enhanced sampling molecular dynamics simulations. H-SSZ-13 zeolite is chosen as a target system. Monte Carlo simulations predict a loading of more than 3 water molecules per unit cell at representative steaming conditions (450 °C, 1 bar steam). Our results show that a higher water loading lowers the free energy barrier of dealumination, as water molecules cooperate to facilitate hydrolysis of Al–O bonds. We find free energies of activation for dealumination that agree well with the available experimental measurements. Clearly, the use of enhanced sampling molecular dynamics yields a major step forward in the molecular level understanding of the dealumination; insight which is very hard to derive experimentally

Valence band study of thermoelectric Zintl-phase SrZn_2Sb_2 and YbZn_2Sb_2: X-ray photoelectron spectroscopy and density functional theory

The electronic structure of SrZn_2Sb_2 and YbZn_2Sb_2 is investigated using density functional theory and high-resolution x-ray photoemission spectroscopy. Both traditional Perdew-Burke-Ernzerhof and state-of-the-art hybrid Heyd-Scuseria-Ernzerhof functionals have been employed to highlight the importance of proper treatment of exchange-dependent Zn  3d states, Yb 4f states, and band gaps. The role of spin-orbit corrections in light of first-principles transport calculations are discussed and previous claims of Yb^(3+) valence are investigated with the assistance of photoelectron as well as scanning and transmission electron microscopy