TWENTY YEARS OF CYBERWAR

For many years after its introduction in the early 1990s, the cyberwar concept - which outlined a new mode of conflict that would emphasize disruption of information systems and flows - was given little credence. Over the past several years, however, cyberwars of both irregular and somewhat more conventional types have erupted (e.g., see respectively Estonia in 2007 and Georgia in 2008). Global awareness of cyberwar has risen sharply, and many nation-states are preparing their defenses, as well as their capabilities for mounting offensive operations. The American military's declaration in 2011 that cyberspace is a 'warfighting domain' highlights a need to explore the ethical implications and nuances of cyberwar. This article finds that classic jus ad bellum constructs come under great pressure from cyberwar, while jus in bello concerns may prove more manageable. Another key theme is that disproportionate attention is given to the notion of employing cyberwar 'strategically' (i.e., to strike directly at other nations' infrastructures), where its use is less likely to achieve 'victory' and is more problematic ethically. Instead, a focus on the application of cyberwar techniques in battle may lead to shorter, less bloody, 'more ethical' conflicts.     

Evaluating appointment postponement in scheduling patients at a diagnostic clinic

Diagnostic clinics are among healthcare facilities that suffer from long waiting times which can worsen medical outcomes and increase patient no-shows. Reducing waiting times without significant capital investments is a challenging task. We tackle this challenge by proposing a new appointment scheduling policy that does not require significant investments for diagnostic clinics. The clinic in our study serves outpatients, inpatients, and emergency patients. Emergency patients must be seen on arrival, and inpatients must be given next day appointments. Outpatients, however, can be given later appointments. The proposed policy takes advantage of this by allowing the postponement of the acceptance of appointment requests from outpatients. The appointment scheduling process is modeled as a two-stage stochastic programming problem where a portion of the clinic capacity is allocated to inpatients and emergency patients in the first stage. In the second stage, outpatients are scheduled based on their priority classes. After a detailed analysis of the solutions obtained from the two-stage stochastic model, we develop a simple, non-anticipative policy for patient scheduling. We evaluate the performance of this proposed, easy-to-implement policy in a simulation study which shows significant improvements in outpatient indirect waiting times.     

Deterrence and overseas stability

The use of conventional armed forces in a deterrent role merits close consideration. Instability in weak or failing states can have global ramifications, while efforts to build stability take time. In principle, conventional deterrence can be used to buy the time required for such stabilization efforts. Attempts at deterrence will, however, need to overcome credibility problems stemming from the technical limitations associated with conventional armed forces, and with the likely requirement for multiple external actors to deter multiple intrastate audiences. While deterrence might work under certain circumstances, it will not play as central a role in strategy as it did during the Cold War.     

Robustness of the normal approximation of lead-time demand in a distribution setting

Previous studies criticize the general use of the normal approximation of lead-time demand on the grounds that it can lead to serious errors in safety stock. We reexamine this issue for the distribution of fast-moving finished goods. We first determine the optimal reorder points and quantities by using the classical normal-approximation method and a theoretically correct procedure. We then evaluate the misspecification error of the normal approximation solution with respect to safety stock, logistics-system costs, total costs (logistics costs, including acquisition costs), and fill rates. The results provide evidence that the normal approximation is robust with respect to both cost and service for seven major industry groups. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 165–186, 1997     

An inventory model of incentives for on-time delivery in just-in-time purchasing contracts

This article formulates an analytic model of just-in-time purchasing contracts and compares the minimum cost solution with the cost attainable through vertical integration. The models use standard inventory theory cost parameters and decision variables. The results quantify the increase in cost of buying an item rather than making it. Optimal incentives are characterized when JIT purchasing contracts are used. When JIT purchasing is implemented, buffer inventories are typically reduced. This inventory reduction makes on-time delivery critical to the buyer; yet timeliness is controlled by the supplier. As an incentive to provide on-time delivery, the buyer offers the supplier a bonus for on-time delivery. The supplier chooses a flow time allowance based upon the bonus offered. First- and second-order conditions are characterized in general, and examples are provided for exponentially and uniformly distributed flow times. The delivery timeliness obtainable in a vertically integrated firm is determined and compared with timeliness obtainable between separate firms. This comparison indicates that buyers who choose to purchase materials from a separate firm are more likely to experience late deliveries. The relationship between the value of the bonus and the proportion of on-time deliveries is also considered. The bonus required to achieve the same probability of on-time delivery as under vertical integration is also determined. © 1993 John Wiley & Sons, Inc.     

Scheduling customer arrivals to a stochastic service system

An efficient algorithm for determining the optimal arrival schedule for customers in a stochastic service system is developed. All customers arrive exactly when scheduled, and service times are modeled as iid Erlang random variables. Costs are incurred at a fixed rate per unit of time each customer waits for service, and an additional cost is incurred for every unit of time the server operates beyond a scheduled closing time. The objective is to minimize total operating cost. This type of problem arises in many operational contexts including transportation, manufacturing, and appointment‐based services. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 549–559, 1999     

Inventory rotation policies for slow moving items

In this article we present a stochastic model for determining inventory rotation policies for a retail firm which must stock many hundreds of distinctive items having uncertain heterogeneous sales patterns. The model develops explicit decision rules for determining (1) the length of time that an item should remain in inventory before the decision is made on whether or not to rotate the item out of inventory and (2) the minimum sales level necessary for retaining the item in inventory. Two inventory rotation policies are developed, the first of which maximizes cumulative expected sales over a finite planning horizon and the second of which maximizes cumulative expected profit. We also consider the statistical behavior of items having uncertain, discrete, and heterogeneous sales patterns using a two-period prediction methodology where period 1 is used to accumulate information on individual sales rates and this knowledge is then used, in a Bayesian context, to make sales predictions for period 2. This methodology assumes that over an arbitrary time interval sales for each item are Poisson with unknown but stationary mean sales rates and the mean sales rates are distributed gamma across all items. We also report the application of the model to a retail firm which stocks many hundreds of distinctive unframed poster art titles. The application provides some useful insights into the behavior of the model as well as some interesting aspects pertaining to the implementation of the results in a “real-world” situation.     

Security sector reform,ethnic representation and perceptions of safety: evidence from Kosovo

This article explores the relationship between ethnic representation in security sector institutions and perceptions of safety. While most studies on post-conflict institutional reform focus on national institutions and outcomes, this article argues that a more nuanced view on ethnic representation is fruitful in order to account for the everyday perceptions of local people. Drawing on post-conflict Kosovo, the article analyzes how the representation of ethnic minorities in security institutions affects perceptions of safety among individuals across Kosovo’s municipalities. It also analyzes original interview data collected in the Pristina and Mitrovica municipalities that are typical cases of our sample. Both approaches validate that those municipalities that have ethnically representative security institutions also have higher levels of perceived safety.