Approximate solution of a profit maximization constrained virtual business planning problem

A virtual business problem is studied, in which a company-contractor outsources production to specialized subcontractors. Finances of the contractor and resource capacities of subcontractors are limited. The objective is to select subcontractors and distribute a part of the demanded production among them so that the profit of the contractor is maximized. A generalization of the knapsack problem, called Knapsack-of-Knapsacks (K-of-K), is used to model this situation, in which items have to be packed into small knapsacks and small knapsacks have to be packed into a large knapsack. A fully polynomial time approximation scheme is developed to solve the problem K-of-K.     

Estimation of Some Nonlinear Panel Data Models With Both Time-Varying and Time-Invariant Explanatory Variables

The so-called “fixed effects” approach to the estimation of panel data models suffers from the limitation that it is not possible to estimate the coefficients on explanatory variables that are time-invariant. This is in contrast to a “random effects” approach, which achieves this by making much stronger assumptions on the relationship between the explanatory variables and the individual-specific effect. In a linear model, it is possible to obtain the best of both worlds by making random effects-type assumptions on the time-invariant explanatory variables while maintaining the flexibility of a fixed effects approach when it comes to the time-varying covariates. This article attempts to do the same for some popular nonlinear models.     

Understanding founder–CEO’s replacement in venture-backed companies: A theoretical and empirical analysis

This research provides an accurate picture of situations in which founder–CEOs are replaced (or not) by venture capitalists. Our analysis aims to go further than the schematic case of the founder being simply dismissed by investors in a conflictual context. We first review the literature dedicated to this subject in the light of the agency theory (AT) and the resource-based view (RBV). However, the limits of these theoretical frameworks lead us to investigate their extensions: the entrenchment theory (ET), the dynamic capabilities approach (DCA) and the cognitive governance perspective (CGP). In a second phase, in order to decode the replacement process, we designed an exploratory methodology based on qualitative data, thus deepening our understanding of the issues it entails in venture-backed companies. Finally, this field analysis allows us to build a typology of replacement scenarii, with each scenario being interpreted by combining relevant theories to explain all aspects of it. In line with the AT, the ET focuses on the FCs strategy to retain their position. The DCA analyses the CEOs’ resources from a dynamic angle, in accordance with the RBV. The CGP is mobilised to characterise a conflict originating in a lack of skills. These results lead us to rethink the role of time and the nature of conflicts in the relationships between FCs and venture capitalists.     

Benefit-of-the-doubt aggregation and the diet problem

In this note we show that the diet problem and the benefit-of-the-doubt (BoD) aggregation are linear programming duals. That is, the primal (dual) formulation of the diet problem is equivalent to the dual (primal) formulation of the BoD model as long as food prices are set equal to one. In addition, we show that the diet problem and the inverted BoD model are linear programming equivalent as long as the nutritional requirements are set equal to one.     

少数民族童谣在铸牢中华民族共同体意识中的教育功能和实现路径

少数民族文化是中华优秀传统的重要组成部分,其中,如“母语记忆”般的少数民族童谣,虽形式短小、简单,却承载着各民族文化的根脉,各民族语言、艺术各具特色,更因历史文化联系多元又一体。笔者通过实地调查、资料收集、整理与比较、文献研究等方式, 认为儿童阶段是播撒中华民族共同体意识种子的基础阶段,少数民族童谣无疑是一种很好的载体,在认知、美育、促进情感发展和文化认同方面可以发挥极大的教育功能。同时提出在教育主战场、文旅融合、创作创新以及儿童活动中的实现路径思考,期待独具魅力的中国少数民族童谣,凝聚成中华民族同心同向的文化力量,蓬勃向上,源远流长！该研究对于推动铸牢中华民族共同体意识,以及我国少数民族地区文化教育、社会稳定、民族团结等方面具有重要的现实意义。     

Human Capabilities Versus Human Capital: Guaging the Value of Education in Developing Countries

The purpose of this study is to defend the view that education should be evaluated in terms of the capability to achieve valued functionings, rather than mental satisfaction or resources. In keeping with Amartya Sen’s capabilities approach we argue that mental satisfaction provides an inaccurate metric of well-being because of the phenomenon of adaptive preferences. Equally, resources cannot be used as a metric of well-being because of inequalities in the ability to convert income and commodities into valued functionings. Hence, interpreting education as a means to create human capital is also impoverished because it evaluates education solely in terms of the accumulation of resources. In order to provide evidence in support of the human capabilities approach we statistically examine the channels through which educational attainment affects the health functionings implied by life expectancy. Using panel data analysis for 35 developing countries for the years 1990, 1995 and 2000 we compare the health functionings (as indicated by life expectancy) that are achieved by the income growth generated by educational attainment, with the total health functionings that are achieved by educational attainment. We find that educational attainment (as indicated by average years of schooling) has a significant effect on life expectancy independently of its effect by way of income growth. A 1% increase in per capita income increases life expectancy by 0.073954% while a 1% increase in average years of schooling directly increases life expectancy by 0.055324%. Because it shows that income underestimates the health functionings achieved by educational attainment, our empirical findings lend support to the claim that the value of education should be measured in terms of the capability for functioning, rather than resources.     

Midwives’ provision of health promotion in antenatal care: A qualitative explorative study

ProblemStudies indicate that health promotion in antenatal care can be improved. Moreover, a schism seems to exist between health promotion and prevention in antenatal care.BackgroundAntenatal care to support and improve maternal health is a core midwifery activity in which prevention as well as HP and woman-centeredness are important.AimTo explore how Danish midwives experienced antenatal care and practiced health promotion.MethodsMidwives undertaking antenatal care were interviewed individually (n = 8) and two focus groups (n = 10) were created. Thematic analysis was performed inductively, and the theoretical models from Piper’s health promotion practice Framework for midwives were used to analyse the midwives’ health promotion approach.FindingsTwo major themes were highlighted. Theme 1: ‘The antenatal care context for health promotion’ described factors contributing to quality in health promotion in antenatal care, such as communication and building relationships with the pregnant women. Theme 2: ‘The health promotion approach in antenatal care’ described both midwife-focused and woman-focused approaches to pregnant women’s health. Barriers to high-quality antenatal care and a holistic health promotion approach were identified, such as shared-care issues, documentation demands and lack of time.DiscussionThe midwives’ experiences were discussed in the context of a health promotion approach. Why midwives practice using a midwife-centred approach has many explanations, but midwives need to learn and help each other understand how they can practice woman-focused care while simultaneously providing prophylactic, evidence-based care.ConclusionMidwives mainly had a midwife-focused approach. To further promote women’s health, midwives need to focus on a woman-focused approach.     

Unsold Versus Unbought Commitment: Minimum Total Commitment Contracts with Nonzero Setup Costs

We study a minimum total commitment (MTC) contract embedded in a finite‐horizon periodic‐review inventory system. Under this contract, the buyer commits to purchase a minimum quantity of a single product from the supplier over the entire planning horizon. We consider nonstationary demand and per‐unit cost, discount factor, and nonzero setup cost. Because the formulations used in existing literature are unable to handle our setting, we develop a new formulation based on a state transformation technique using unsold commitment instead of unbought commitment as state variable. We first revisit the zero setup cost case and show that the optimal ordering policy is an unsold‐commitment‐dependent base‐stock policy. We also provide a simpler proof of the optimality of the dual base‐stock policy. We then study the nonzero setup cost case and prove a new result, that the optimal solution is an unsold‐commitment‐dependent (s, S) policy. We further propose two heuristic policies, which numerical tests show to perform very well. We also discuss two extensions to show the generality of our method's effectiveness. Finally, we use our results to examine the effect of different contract terms such as duration, lead time, and commitment on buyer's cost. We also compare total supply chain profits under periodic commitment, MTC, and no commitment.     

Information Diffusion among Agents: Implications for Humanitarian Operations

The basis for this article is an information‐processing view of the UN's cluster approach. We use agent‐based modeling and simulations to show that clusters, if properly utilized, encourage better information flow and thus facilitate effective response to disasters. The article intends to turn the attention of the humanitarian community to the importance of sharing information and the role of cluster leads in facilitating humanitarian aid. Our results indicate that if cluster leads act as information hubs, information reaches its target faster, enabling a prompt humanitarian response. In addition, we show that information quality is critical for effective resource utilization—if cluster leads filter information, it moves faster. We also found evidence that the willingness to exchange information plays a larger role in transmitting information than that of an information hub, particularly during later stages of response operations.     

Bounds of Relative Regret Limit in p‐Robust Supply Chain Network Design

This research studies the p‐robust supply chain network design with uncertain demand and cost scenarios. The optimal design integrates the supplier selection together with the facility location and capacity problem. We provide a new framework to obtain the relative regret limit, which is critical in the robust supply chain design but is assumed to be a known value in the existing literature. We obtain lower and upper bounds for relative regret limit and obtain a sequence of optimal solutions for series relative regret limits between the upper and lower bounds. An algorithm for p‐robust supply chain network design is provided. A series of numerical examples are designed to find the properties of the bottleneck scenarios. A scenario with low probability and a low optimal objective function value for the scenario has a greater chance of being a bottleneck. To focus only on the influence from the relative regret, we also introduce three separate new objective functions in p‐robust design. The proposed new theories and approaches provide a sequence of options for decision makers to reduce the marketing risks effectively in supply chain network design.