Parents,Perceptions and Belonging: Exploring Flexible Working among UK Fathers and Mothers

This paper advances knowledge regarding how fathers and mothers perceive and experience flexible working opportunities. It does this through applying the theoretical concept ‘belonging’ to ‘Parsonian’ classifications of parenting and work. In so doing it makes transparent the misconceptions and inequities which exist among parents and their organizational environments. Focusing initially on a qualitative study of fathers’ experience of working flexibly, the paper shows how fathers felt marginalized from the possibilities of flexible work due to line managers’ assumptions that men belonged to an ‘instrumental’ economic provider group. The paper contributes a new angle to debate by articulating how fathers perceived employed mothers as belonging to an ‘expressive’ child‐oriented group, with privileged access to flexibility. However, drawing upon a study of maternity and flexible work we query fathers’ assumptions that flexibility was easily available to mothers, suggesting that fathers’ perceptions of maternal privilege were misconceived. While mothers were categorized as belonging within an ‘expressive’ group associated with childcare, they were nevertheless discouraged from accessing flexibility. Inequities between women and men (with regard to flexibility) thus appeared to be less significant than fathers supposed.     

On-line bin packing with restricted repacking

Semi-on-line algorithms for the bin-packing problem allow, in contrast to pure on-line algorithms, the use of certain types of additional operations for each step. Examples include repacking, reordering or lookahead before packing the items. Here we define and analyze a semi-on-line algorithm where for each step at most k items can be repacked, for some positive integer k. We prove that the upper bound for the asymptotic competitive ratio of the algorithm is a decreasing function of k, which tends to 3/2 as k goes to infinity. We also establish lower bounds for this ratio and show that the gap between upper and lower bounds is relatively small.     

Generalized perfect domination in graphs

Let k be a positive integer and G=(V,E) be a graph. A vertex subset D of a graph G is called a perfect k-dominating set of G, if every vertex v of G, not in D, is adjacent to exactly k vertices of D. The minimum cardinality of a perfect k-dominating set of G is the perfect k-domination number γ _kp (G). In this paper, we give characterizations of graphs for which γ _kp (G)=γ(G)+k?2 and prove that the perfect k-domination problem is NP-complete even when restricted to bipartite graphs and chordal graphs. Also, by using dynamic programming techniques, we obtain an algorithm to determine the perfect k-domination number of trees.     

Partially Flexible Operating Rooms for Elective and Emergency Surgeries

In hospitals, the management of operating rooms faces a trade‐off between the need to be responsive to emergency surgeries and to conduct scheduled elective surgeries efficiently. Operating rooms can be configured as flexible and handle both electives and emergencies, or as dedicated to focus on either electives or emergencies. With flexible rooms, the prioritization of emergencies over scheduled electives can lead to schedule disruptions. Focused rooms can lead to imbalances between capacity and surgery workload. Whereas hospital administrators typically handle this trade‐off by employing either flexible rooms (complete flexibility) or dedicated rooms (complete focus), we investigate whether a combination of flexible and dedicated rooms (partial flexibility) could be a preferable alternative. The ensuing question is what is the right combination of flexible and dedicated rooms? A versatile simulation model is developed to evaluate different resource allocation policies under various environmental parameters and performance metrics, including patient wait time, staff overtime, and operating room utilization. The main result is that partial flexibility configurations outperform both complete flexibility and complete focus policies by providing solutions with improved values of expected wait time for both emergency and elective patients.     

The Effect of Demand–Supply Mismatches on Firm Risk

A supply chain management (SCM) system comprises many subsystems, including forecasting, order management, supplier management, procurement, production planning and control, warehousing and distribution, and product development. Demand–supply mismatches (DSMs) could indicate that some or all of these subsystems are not working as expected, creating uncertainties about the overall capabilities and effectiveness of the SCM system, which can increase firm risk. This article documents the effect of DSMs on firm risk as measured by equity volatility. Our sample consists of three different types of DSMs announced by publicly traded firms: production disruptions, excess inventory, and product introduction delays. We find that all three types of DSMs result in equity volatility increases. Over a 2‐year period around the announcement date, we observe mean abnormal equity volatility increases of 5.62% for production disruptions, 11.19% for excess inventory, and 6.28% for product introduction delays. Volatility increases associated with excess inventory are significantly higher than the increases associated with production disruptions and product introduction delays. Across all three types of DSMs, volatility changes are positively correlated with changes in information asymmetry. The results provide some support that volatility changes are also correlated with changes in financial and operating leverage.     

Optimal Inventory Control with Retail Pre‐Packs

A pre‐pack is a collection of items used in retail distribution. By grouping multiple units of one or more stock keeping units (SKU), distribution and handling costs can be reduced; however, ordering flexibility at the retail outlet is limited. This paper studies an inventory system at a retail level where both pre‐packs and individual items (at additional handling cost) can be ordered. For a single‐SKU, single‐period problem, we show that the optimal policy is to order into a “band” with as few individual units as possible. For the multi‐period problem with modular demand, the band policy is still optimal, and the steady‐state distribution of the target inventory position possesses a semi‐uniform structure, which greatly facilitates the computation of optimal policies and approximations under general demand. For the multi‐SKU case, the optimal policy has a generalized band structure. Our numerical results show that pre‐pack use is beneficial when facing stable and complementary demands, and substantial handling savings at the distribution center. The cost premium of using simple policies, such as strict base‐stock and batch‐ordering (pre‐packs only), can be substantial for medium parameter ranges.     

TOP INCOMES IN THE NETHERLANDS AND THE UNITED KINGDOM OVER THE 20TH CENTURY

A method is developed for using income‐tax data to investigate the evolution of the highest incomes over virtually the entire 20th century. The income shares of the top 10, 5, 1, 0.5, 0.1, and 0.05 percent are analysed for the UK and the Netherlands. For considering the top shares among themselves the “Pareto–Lorenz coefficient” is proposed. Between the two countries, the top shares appear to undergo a strikingly similar and strong decline up to the mid‐1970s. Since then British top shares have increased significantly while Dutch shares remained basically unchanged. This outcome parallels similar results for the US and France obtained by Piketty and Saez and poses interesting questions for research. (JEL: N34, D31, O15)     

Tolerable or Acceptable: A Comparison of Risk Regulation in the United Kingdom and in the Netherlands

In managing major accident hazards in industry risk, both the United Kingdom and the Netherlands use quantitative risk analysis and quantified risk criteria. These should be understood in the historical, legal, and political context in which they were drawn up. Even when criteria are numerically the same they do not necessarily mean the same thing. The legal and historical context differs widely between the two countries. Nevertheless, it is surprising that the final results in terms of land use and levels of risk are very similar.     

Generating a smallest binary tree by proper selection of the longest edges to bisect in a unit simplex refinement

In several areas like global optimization using branch-and-bound methods for mixture design, the unit n-simplex is refined by longest edge bisection (LEB). This process provides a binary search tree. For \(n>2\), simplices appearing during the refinement process can have more than one longest edge (LE). The size of the resulting binary tree depends on the specific sequence of bisected longest edges. The questions are how to calculate the size of one of the smallest binary trees generated by LEB and how to find the corresponding sequence of LEs to bisect, which can be represented by a set of LE indices. Algorithms answering these questions are presented here. We focus on sets of LE indices that are repeated at a level of the binary tree. A set of LEs was presented in Aparicio et al. (Informatica 26(1):17–32, 2015), for \(n=3\). An additional question is whether this set is the best one under the so-called \(m_k\)-valid condition.