On the total outer-connected domination in graphs

A set S of vertices of a graph G is a total outer-connected dominating set if every vertex in V(G) is adjacent to some vertex in S and the subgraph induced by V?S is connected. The total outer-connected domination number γ _toc (G) is the minimum size of such a set. We give some properties and bounds for γ _toc in general graphs and in trees. For graphs of order n, diameter 2 and minimum degree at least 3, we show that $\gamma_{toc}(G)\le \frac{2n-2}{3}$ and we determine the extremal graphs.     

Incentives in a Stage‐Gate Process

Many large organizations use a stage‐gate process to manage new product development projects. In a typical stage‐gate process project managers learn about potential ideas from research and exert effort in development while senior executives make intervening go/no‐go decisions. This decentralized decision making results in an agency problem because the idea quality in early stages is unknown to the executive and the project manager must exert unobservable development effort in later stages. In light of these challenges, how should the firm structure incentives to ensure that project managers reveal relevant information and invest the appropriate effort to create value? In this study, we develop a model of adverse selection in research and moral hazard in development with a go/no‐go decision at the intervening gate. Our results show that the principal's uncertainty regarding early‐stage idea quality—a term we refer to as idea risk—alters the effect of late‐stage development risk. The presence of idea risk can alter the incentives offered to the agent and may lead the principal to reject projects that otherwise seem favorable in terms of positive net present value. A simulation of early‐stage ideas, found through search on a complex landscape, shows that the firm can mitigate the negative effects of idea risk by encouraging breadth of search and high tolerance for failure.     

A New Era in Governmental Reform: Realizing Community

The good government models of the 1990s realized a focus that included reinventing, reengineer-ing, rethinking, quality, empowerment, and devolution of the organization. These organizational reform ideologies sought to increase involvement, improve productivity, manage performance, and drive results. One essential key that has been disregarded in these government models is the involvement of community in the decision-making process. This paper points to the importance of involving and empowering citizens in the decision-making process, particularly in regard to community justice based on the notion of restorative justice system. Community justice, a modern day reform movement with international proportions, is based on the principles of empowering community, repairing harm caused by a crime or disturbance, and reducing risk to the community.     

Risk Estimation and Value-of-Information Analysis for Three Proposed Genetic Screening Programs for Chronic Beryllium Disease Prevention

Genetic differences (polymorphisms) among members of a population are thought to influence susceptibility to various environmental exposures. In practice, however, this information is rarely incorporated into quantitative risk assessment and risk management. We describe an analytic framework for predicting the risk reduction and value-of-information (VOI) resulting from specific risk management applications of genetic biomarkers, and we apply the framework to the example of occupational chronic beryllium disease (CBD), an immune-mediated pulmonary granulomatous disease. One described Human Leukocyte Antigen gene variant, HLA-DP beta 1*0201, contains a substitution of glutamate for lysine at position 69 that appears to have high sensitivity (approximately 94%) but low specificity (approximately 70%) with respect to CBD among individuals occupationally exposed to respirable beryllium. The expected postintervention CBD prevalence rates for using the genetic variant (1) as a required job placement screen, (2) as a medical screen for semiannual in place of annual lymphocyte proliferation testing, or (3) as a voluntary job placement screen are 0.08%, 0.8%, and 0.6%, respectively, in a hypothetical cohort with 1% baseline CBD prevalence. VOI analysis is used to examine the reduction in total social cost, calculated as the net value of disease reduction and financial expenditures, expected for proposed CBD intervention programs based on the genetic susceptibility test. For the example cohort, the expected net VOI per beryllium worker for genetically based testing and intervention is $13,000, $1,800, and $5,100, respectively, based on a health valuation of $1.45 million per CBD case avoided. VOI results for alternative CBD evaluations are also presented. Despite large parameter uncertainty, probabilistic analysis predicts generally positive utility for each of the three evaluated programs when avoidance of a CBD case is valued at $1 million or higher. Although the utility of a proposed risk management program may be evaluated solely in terms of risk reduction and financial costs, decisions about genetic testing and program implementation must also consider serious social, legal, and ethical factors.     

AN IMPROVED HEURISTIC FOR STAFFING TELEPHONE CALL CENTERS WITH LIMITED OPERATING HOURS

Many telephone call centers that experience cyclic and random customer demand adjust their staffing over the day in an attempt to provide a consistent target level of customer service. The standard and widely used staffing method, which we call the stationary independent period by period (SIPP) approach, divides the workday into planning periods and uses a series of stationary independent Erlang‐c queuing models—one for each planning period—to estimate minimum staffing needs. Our research evaluates and improves upon this commonly used heuristic for those telephone call centers with limited hours of operation during the workday. We show that the SIPP approach often suggests staffing that is substantially too low to achieve the targeted customer service levels (probability of customer delay) during critical periods. The major reasons for SIPP‘ s shortfall are as follows: (1) SIPP's failure to account for the time lag between the peak in customer demand and when system congestion actually peaks; and (2) SIPP’ s use of the planning period average arrival rate, thereby assuming that the arrival rate is constant during the period. We identify specific domains for which SIPP tends to suggest inadequate staffing. Based on an analysis of the factors that influence the magnitude of the lag in infinite server systems that start empty and idle, we propose and test two simple “lagged” SIPP modifications that, in most situations, consistently achieve the service target with only modest increases in staffing.     

Psychosocial versus biomedical risk factors in Kevorkian's first forty-seven physician-assisted deaths

This article examines biomedical and psychosocial data on the first forty-seven cases of physician-assisted suicide (PAS) of Kevorkian as collected by means of both a physical autopsy and a preliminary psychological autopsy. The following patterns emerge: 1) The physical condition of these PAS patients was not typical of the conditions that lead to death in the United States. 2) Consistent with the above findings, our pilot data indicate that only 31.1 percent of these patients were terminal. While 73.9 percent were described as reporting pain, only 42.6 percent were revealed at autopsy to have a specific anatomical basis for their pain. However 36 percent were described as depressed, 66 percent as having some disability, and perhaps of key importance, 90 percent expressed a fear of dependency. Most important, our pilot data suggest the possibility of large gender differences, since 3) 68.1 percent of these forty-seven PAS's are women and only 31.9 percent are men. This represents the reverse of the gender pattern for completed suicides in the United States in 1995, resembling instead the approximate pattern for unsuccessful suicide attempts. 4) Approximately 75 percent of both men and women in the above sample were described as reporting pain. Men were almost twice as likely to have had an anatomical basis for the pain and three times as likely to be terminal. Our pilot data indicate PAS women are more likely to be described as depressed and twice as likely to have had a history of previous unsuccessful suicide attempts. 5) Kevorkian's patients were older than the typical unaided suicides in America. Reported pain decreases with age as does depression; however anatomical basis for pain increases slightly with age, and no age effect emerges for terminality. 6) Approximately two-thirds of those physician-assisted suicides were at middle SES levels. History of disability was the biggest risk factor for the low SES patients and fear of dependency for the high SES patients.     

How to shape positive relationships in medical practices and hospitals

Managing workplace conflict is one of the most important, stressful, and time-consuming tasks faced by today's medical leaders. Poorly managed workplace conflict can alienate patients, demoralize staff, increase turnover, damage relationships with valued referral sources and third party carriers concerned about patient satisfaction, and lead medical practices to costly "corporate divorces." Physician executives cannot solve the problems caused by disruptive doctors simply by bolstering their own conflict management skills or by policing offenders. The larger contexts within which inappropriate workplace behavior occurs must also be assessed and addressed. The true leadership challenge is to intervene in ways that help to foster a "culture" of appropriate interpersonal dynamics throughout your organization. This requires learning to think and to intervene systematically.