Noise and vibration measurements in a Viking military vehicle

Noise and whole-body vibration measurements were made in a Viking military vehicle to determine the variation that should be expected during repeat measures, the effect of speed (up to 60 km/h in 5 km/h increments), and during travel over different types of terrain (comprising concrete road, gravel track and rough cross-country). Measurements were made at various crew positions (including the driver and commander) in both the front and the rear cabs in the vehicles. Three translational axes of vibration were measured in each seat. Two speeds were investigated over road (35 km/h and 55–60 km/h) and gravel (20 km/h and 35 km/h) surfaces. The effect of varying speed of the vehicle on the measured noise and vibration magnitudes was also investigated. The highest sound pressure level (L_Aeq) of 104 dB(A) was measured at the commander’s standing position during travel over concrete road at 55 km/h. Higher noise levels occurred for a standing commander compared with when sitting on the seat. A maximum single axis frequency-weighted vibration magnitude of 1.0 m/s² r.m.s. was measured on the driver’s seat during travel over track at 35 km/h. Higher vibration magnitudes occurred during travel over track compared with travel over road. Both noise and vibration exposure of crew within the Viking vehicle increased with increasing speed of the vehicle.     

舰船研制中设计余量的权衡分析

分析了舰船及其装备研制的时间特点 ,给出了用于预测的空间特性有关计算公式 .对设计余量的种类和体现方式进行了讨论 ,并对国内外现有设计实例进行了详细的得失分析和权衡 ,在此基础上提出了分析结论 .     

Incorporation dynamic aspects and uncertainty in 1‐median location problems

In this paper we present several 1‐median formulations on a tree network which incorporate dynamic evolution and/or uncertainty of node demands and transportation costs over a planning horizon. Dynamic evolution is modeled using linear demand functions for the nodes and linear length functions for the edges. Uncertainty is modeled with the use of multiple scenarios, where a scenario is a complete specification of the uncertain node demands and/or edge lengths. We formulate our objective using minimax regret like criteria. We use two different criteria, namely, robust deviation and relative robustness. We discuss what motivated the introduction of these objectives, as well as their relation to existing literature and decision making practices. For all of the models presented, we provide low‐order polynomial time algorithms. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 147–168, 1999     

The dynamic lot size model with quantity discount: Counterexamples and correction

Federgruen and Lee ([3]) proposed an optimal algorithm for the single-item dynamic lot size model with all-unit discount. In this note we show that their algorithm fails to find the optimal solution for some special cases. We also provide a modification to the algorithm to handle them. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 419–422, 1998     

Interchange fees for bank ATM networks

Banks have found it advantageous to connect their Automated Teller Machines (ATMs) in networks so that customers of one bank may use the ATMs of any bank in the network. When this occurs, an interchange fee is paid by the customer's bank to the one that owns the ATM. These have been set by historic interbank negotiation. The paper investigates how a model based on n-player game theory concepts of Shapley value and nucleolus could be used as an alternative way of setting such fees. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 407–417, 1998     

A robust regression technique using compound estimation

Least squares fitting of regression models is a widely used technique. The presence of outliers in the data can have an adverse effect on the method of least squares, resulting in a model that does not adequately fit to the bulk of the data. For this situation, robust regression techniques have been proposed as an improvement to the method of least squares. We propose a robust regression procedure that performs well relative to the current robust methods against a variety of dataset types. Evaluations are performed using datasets without outliers (testing efficiency), with a large percentage of outliers (testing breakdown), and with high leverage outliers (testing bounded influence). The datasets are based on 2-level factorial designs that include axial points to evaluate leverage effects. A Monte Carlo simulation approach is used to evaluate the estimating capability of the proposed procedure relative to several competing methods. We also provide an application to estimating costs for government satellites. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 125–139, 1998     

Shortest path interdiction problem with arc improvement recourse: A multiobjective approach

We consider the shortest path interdiction problem involving two agents, a leader and a follower, playing a Stackelberg game. The leader seeks to maximize the follower's minimum costs by interdicting certain arcs, thus increasing the travel time of those arcs. The follower may improve the network after the interdiction by lowering the costs of some arcs, subject to a cardinality budget restriction on arc improvements. The leader and the follower are both aware of all problem data, with the exception that the leader is unaware of the follower's improvement budget. The effectiveness of an interdiction action is given by the length of a shortest path after arc costs are adjusted by both the interdiction and improvement. We propose a multiobjective optimization model for this problem, with each objective corresponding to a different possible improvement budget value. We provide mathematical optimization techniques to generate a complete set of strategies that are Pareto‐optimal. Additionally, for the special case of series‐parallel graphs, we provide a dynamic‐programming algorithm for generating all Pareto‐optimal solutions.