Comment on “Approximation algorithms for quadratic programming”

Journal of Combinatorial Optimization - The radius of the outer Dikin ellipsoid of the intersection of m ellipsoids due to Fu et al. (J. Comb. Optim., 2, 29-50, 1998) is corrected from m to...     

The economic case for “High performance buildings”

A well-planned approach to building design and development can lead to the construction of facilities that are green “both ways”—that is, facilities that are not only more environmentally-benign, but also facilities that are more economically-beneficial for their owners and operators than those based on more traditional designs, processes, and materials. “Green buildings,” or “high performance buildings” as they are increasingly being called, are being commissioned in growing numbers. As more of these facilities come on line, the data supporting the economic case for them is also growing, and that case is very compelling. In this article, the author examines comparisons between traditional and “high performance” buildings to highlight the long-term competitive advantage.     

Strategies for leader cognition: Viewing the glass “half full” and “half empty”

Leader cognition proves to be central to organizational functioning as leaders generate solutions and provide direction when organizations encounter problems. This study examined the effects of utilizing different general thinking strategies for thinking through organizational problems on the formation of problem solutions and statements articulating a future vision. Specifically, the effects of focusing on the positive, the negative, or balancing positivity and negativity were examined regarding their influence on the quality, originality, and elegance of solutions and the viability of vision statements. Participants were asked to assume the role of a leader in an educational technology firm and provide a solution and vision statement to address the firm's challenges. The results revealed that a positivity strategy – thinking about positive outcomes and means for attaining success – resulted in lower quality solutions and less viable visions than a balanced positive–negative strategy—either thinking about negative outcomes and means for attaining success or positive outcomes and means for avoiding failure. Solution originality, however, was moderated by attribution of responsibility such that thinking about negative outcomes and avoiding failure resulted in more original solutions when responsibility for the conditions confronting the firm could be attributed externally rather than internally. The implications of these findings for understanding leader cognition and performance are discussed.     

Preparing for business model change: the “pre-stage” finding

The purpose of this paper is to investigate managers’ initiatives in the context of an emergent technology and their effect on the business models of firms. Building on four case studies of organizations interested in using an emergent technology for commercial purposes, this study applies a process-based framework of business model change. The main finding is that managers’ initiatives occur in the context of a “pre-stage” of potential business model change, which includes processes of experimenting and learning. The pre-stage finding gives a better understanding of when change initiatives affect a business model and when they do not, allowing managers to adopt a more proactive behaviour and guide their organizations towards effective business model change. The main contribution of this paper is to suggest the inclusion of the pre-stage idea in research and practice, since it is an intermediary step in the process of business model change that has been overlooked.     

A model for regulatory reform in Canada: From “command-and-control” to “assured compliance”

Due, in part, to severe budget constraints, the Alberta Energy and Utilities Board (EUB) moved from a traditional command-and-control regulatory system to a system that incorporates several characteristics of self-regulation. The EUB, the regulatory body for the energy industry in Alberta, Canada, refers to the new system as “compliance assured by audit and penalty”. This new system, which may have relevance to other nations struggling with similar developments, utilizes a classification scheme based on a company's past performance. This allows the EUB to target resources toward companies identified as having the greatest need for regulatory performance improvement. This case study discusses the drivers for change, the process of change and the lessons learned, and raises several questions relating to the business implications.     

Contingencies or cognitions? Two paths for research on organization and technology

This article reviews and criticizes the treatment of the concepts of technology in organization theories. It pays special attention to how authors of the contingency school interpret empirical results concerning relationships between technology and organization structure. When authors have encountered contradictory results, they attempt to find flaws in previous research and to ask for methodologically more precise research. As this way of dealing with anomalies yields little fruit in the long run, organization theorists need new frameworks for investigating the significance of technology for the design of organizations. An actor-oriented approach can frame investigations into the cognitive processes dissolving or modifying the relationships.     

Optimal semi-online algorithm for scheduling with rejection on two uniform machines

In this paper we consider a semi-online scheduling problem with rejection on two uniform machines with speed 1 and s≥1, respectively. A sequence of independent jobs are given and each job is characterized by its size (processing time) and its penalty, in the sense that, jobs arrive one by one and can be either rejected by paying a certain penalty or assigned to some machine. No preemption is allowed. The objective is to minimize the sum of the makespan of schedule, which is yielded by all accepted jobs and the total penalties of all rejected ones. Further, two rejection strategies are permitted thus an algorithm can propose two different schemes, from which the better solution is chosen. For the above version, we present an optimal semi-online algorithm H that achieves a competitive ratio ρ _H (s) as a piecewise function in terms of the speed ratio s.     

Where To Go From Here? Thoughts on Future Directions for Research on Individual‐Level Technology Adoption with a Focus on Decision Making*

This article recognizes the maturity of individual‐level technology‐adoption research and suggests three broad future research directions. They are: (i) business process change and process standards, (ii) supply‐chain technologies, and (iii) services. Each of these areas is identified based on the topics likely of interest to the readers of the Decision Sciences by closely examining Decision Sciences' editorial mission and the recent research published in it. Within each of these three different broad topic areas, a few different specific directions are identified. The directions outlined here are not meant to be exhaustive but rather potential directions that can result in a theoretical contribution to individual‐level technology‐adoption research and the specific topic area.     

Redundant configuration of automated flow lines based on “Industry 4.0”-technologies

Over the past decades, robots have been heavily used for flow lines to increase productivity and product quality and to relieve workers of repetitive and dangerous tasks. However, despite continuous improvement of robots, the occurrence of failures remains a significant challenge in the operation of automated flow lines. Due to the connection of the stations in a flow line via a material handling system, failures at one station can quickly lead to throughput losses due to blocking and starving of upstream and downstream stations, respectively. To some extent, these throughput losses can be reduced by installing buffers between the stations. However, the installation of buffers requires considerable investments and scarce factory space. Therefore, the minimization of the total number of buffers is one of the primary objectives in flow line planning. Due to the advances of manufacturing technologies that form the foundation of “Industry 4.0”, new solutions to reduce throughput losses caused by equipment failures open up. One solution is a redundant configuration, in which downstream stations automatically take over the operations of failed stations in the event of failure. The throughput loss in these situations mainly depends on the level of redundancy designed into the system. Based on existing methods for the design of automated flow lines, we present two line balancing formulations for the configuration of automated flow lines under consideration of redundancies. The first formulation aims at maximizing the lines’ level of redundancy. The second formulation aims at a balanced allocation of redundancies along the line. To evaluate the presented formulations, we compare the performance with an existing line balancing approach for automated lines. With respect to this approach, improvements of the throughput rate between 3 % and 7 % are achieved.     

Voter’s Perceptions on Candidate Choice for Director of Public Educational Institutions

Public Organization Review - This study aimed to verify whether the voters’ perceptions (trust, expertise, attractiveness, image and perceived quality) from the academic community influence...     

A modularised typology for flow design based on decoupling points – a holistic view on process industries and discrete manufacturing industries

Management of production activities covers a wide range of decisions. In this paper, a modularised approach is suggested that, through configuration, generates a case-specific flow design. The approach is based on identification of decision categories that are generic and fundamental in the flow design, covering both discrete manufacturing industries and process industries. Each decision category identifies a unique property of the flow which changes at a particular point: this is termed a ‘decoupling point’. A three-dimensional modularised typology is developed by combining three different decision categories. Cases from the steel industry and the tooling industry are used to illustrate how the typology can be applied. The modularised approach provides a typology for the application of both qualitative and quantitative methods for flow management, including planning, control and performance management.     

What is the “right” market orientation for new entrepreneurial ventures?

A general notion in research on entrepreneurial marketing is that new ventures that adopt both strong market orientation and entrepreneurial orientation outperform other firms. The present research provides a more fine-grained analysis of this common wisdom. First, while extant research focuses on responsive market orientation, this research seeks to differentiate responsive from proactive market orientations in young ventures. Second, the study examines the moderating effects of the degree of entrepreneurial orientation on proactive and responsive market orientation’s performance consequences in the context of new ventures since these ventures must understand which orientations are worth pursuing, especially given their resource constraints. The theoretically developed research model is tested using survey data of 259 ventures in operation less than fifteen years from five national cultures in order to detect national dependencies and establish the robustness of the findings. Recommendations concerning which type of market orientation entrepreneurial and less entrepreneurial new ventures should follow are provided.     

A new model for successful management of engineering design firms — “superpositioning”

A SuperPositioning model for successful management of engineering design firms is discussed which allows firms to be categorized within a matrix bounded by two primary drivers, their engineering Design Techology (how they do their work) and their Values (the primary reward thrusts or motivations of the owners). Technologies are separated into Strong Idea (Brains), Strong Service (Gray Hair) and Strong Delivery (Routine Procedure). Values are divided between Practice Centered Business and Business Centered Practice.The firm's Design Technology affects the optimal way it should handle Project Design, Project Decision Making, Middle and Lower Level Staffing, Markets, What it Sells, What it Can Charge, and Best Management Style. Its choice of Values impacts the Organization Structure, Organization Decision-Making, Staffing at the Top, How it Markets, Best Clients, Marketing Organization, Profit Strategy, Reward and Management Style. Firms that optimize their strategies for these elements to match their choice of drivers are observed to perform better for their clients and in terms of their owner's satisfaction.     

A short proof of a result on a Vizing-like problem for integer total domination

In this note, we provide a short proof of a recent result on a Vizing-like problem for integer total domination in graphs given by Li and Hou (J. Comb. Optim., 2008).     

A polynomial time approximation scheme for?embedding a directed hypergraph on a weighted ring

Given a directed hypergraph H=(V,E _H ), we consider the problem of embedding all directed hyperedges on a weighted ring. The objective is to minimize the maximum congestion which is equal to the maximum product of the weight of a link and the number of times that the link is passed by the embedding. In this paper, we design a polynomial time approximation scheme for this problem.     

A Comparison of Regulatory Implications of Traditional and Exact Two-Stage Dose–Response Models

We compare the regulatory implications of applying the traditional (linearized) and exact two-stage dose–response models to animal carcinogenic data. We analyze dose–response data from six studies, representing five different substances, and we determine the goodness-of-fit of each model as well as the 95% confidence lower limit of the dose corresponding to a target excess risk of 10^–5 (the target risk dose TRD). For the two concave datasets, we find that the exact model gives a substantially better fit to the data than the traditional model, and that the exact model gives a TRD that is an order of magnitude lower than that given by the traditional model. In the other cases, the exact model gives a fit equivalent to or better than the traditional model. We also show that although the exact two-stage model may exhibit dose–response concavity at moderate dose levels, it is always linear or sublinear, and never supralinear, in the low-dose limit. Because regulatory concern is almost always confined to the low-dose region extrapolation, supralinear behavior seems not to be of regulatory concern in the exact two-stage model. Finally, we find that when performing this low-dose extrapolation in cases of dose–response concavity, extrapolating the model fit leads to a more conservative TRD than taking a linear extrapolation from 10% excess risk. We conclude with a set of recommendations.