THE OPTIMUM SPEED OF VISUAL INSPECTION USING A RANDOM SEARCH STRATEGY

Choosing a standard speed for visual inspection is difficult using standard work measurement techniques. This paper uses a different approach, taking a model of human functioning in inspection and deriving an optimum speed of working so as to balance the cost of time against the cost of errors. Random search is used as the model and both self-paced and externally-paced conditions are derived for multiple fault types. Optimization using a Golden Section search is used to provide optimum inspection speed.     

Combining a new data classification technique and regression analysis to predict the Cost-To-Serve new customers

Identifying the Cost-To-Serve (CTS) of customers is one of the most challenging problems in Supply Chain Management because of the diversity in their business activities. For the particular case of the industrial gas business, we are interested in predicting the cost to deliver bulk (liquefied) gas to new customers using a multifactor linear regression model. Developing a single model, i.e. analyzing the observations all at once, produces poor prediction results. Therefore prior to the regression analysis, a new supervised learning technique is used to group customers who are similar in some sense. Classes of customers are represented by hyper-boxes and a linear regression model is subsequently built within each class. The combination of data classification and regression is proven to increase the accuracy of the prediction.Two Mixed-Integer-Linear Programming (MILP) models are developed for data classification purposes. Although we are dealing with a supervised learning method, classes are not predefined in our case. Rather, we input a continuous “classification” attribute that is optimally discretized by the MILP’s in order to minimize the number of misclassifications. Therefore our data classification model offers a broader range of applications. A number of illustrative examples are used to prove the effectiveness of the proposed approach.     

Household Activity Pattern Problem with Autonomous Vehicles

Networks and Spatial Economics - The pace of changes in automating cars has sped up in the last few decades. Autonomous Vehicles (AVs) will dramatically change the future of transportation, and...     

Fabrication of Ultrasensitive TES Bolometric Detectors for HIRMES

The high-resolution mid-infrared spectrometer (HIRMES) is a high resolving power (R ~?100,000) instrument operating in the 25–122 μm spectral range and will fly on board the Stratospheric Observatory for Far-Infrared Astronomy in 2019. Central to HIRMES are its two transition edge sensor (TES) bolometric cameras, an 8 × 16 detector high-resolution array and a 64 × 16 detector low-resolution array. Both types of detectors consist of Mo/Au TES fabricated on leg-isolated Si membranes. Whereas the high-resolution detectors, with a noise equivalent power (NEP) ~ 1.5 × 10^?18 W/rt (Hz), are fabricated on 0.45 μm Si substrates, the low-resolution detectors, with NEP ~ 1.0 × 10^?17 W/rt (Hz), are fabricated on 1.40 μm Si. Here, we discuss the similarities and differences in the fabrication methodologies used to realize the two types of detectors.     

Operations planning with real time pricing of a primary input

We examine the problem of planning the operation of an air separation plant where the price of its primary production input, electricity, changes hour to hour, a situation commonly referred to as real time pricing (RTP). We present a solution approach where operating decisions are obtained from optimizing a mixed integer program embedded in a rolling horizon procedure. A simulation study is conducted to assess the effect of unreliable and finite information on the efficiency of the operations plans generated by the procedure. Results of the study suggest that the rolling horizon procedure generates robust plans. An additional simulation study is conducted to identify the conditions under which RTP is attractive vis-a-vis other selected electricity pricing schemes. Results of the study indicate that RTP is most appealing when there is substantial flexibility in the operating environment in terms of the load placed on the plant (customer demand) and with regard to ramp-up (akin to set-up) times. Although this appeal diminishes with increased loads and longer ramp-ups, it is nevertheless the case that the operational inflexibility must be significant before RTP loses its allure.     

An Integrative Model-Based Approach to Hospital Layout

The issues of facility layout and bed allocation in health care settings are typically evaluated separately using very different model-based approaches. This paper describes a two-phase approach to the hospital layout problem that incorporates a number of considerations from typical layout models and methods used in determining bed allocations. The first phase involves a quadratic integer goal programming model that determines a configuration and recommended allocation of beds to hospital services. The detailed ramifications of the proposed layout are then evaluated in the second phase via a simulation model. The application of the optimization-simulation approach in a general purpose hospital is described.     

Scp160p,a new yeast protein associated with the nuclear membrane and the endoplasmic reticulum,is necessary for maintenance of exact ploidy

We have cloned a new gene, SCP160, from Saccharomyces cerevisiae, the deduced amino acid sequence of which does not exhibit overall similarity to any known yeast protein. A weak resemblance between the C-terminal part of the Scp160 protein and regulatory subunits of cAMP-dependent protein kinases from eukaryotes as well as the pstB protein of Escherichia coli was observed. The SCP160 gene resides on the left arm of chromosome X and codes for a polypeptide of molecular weight around 160 kDa. By immunofluorescence microscopy the Scp160 protein appears to be localized to the nuclear envelope and to the endoplasmic reticulum (ER). However, no signal sequence or membrane-spanning region exists, suggesting that the Scp160 protein is attached to the cytoplasmic surface of the ER–nuclear envelope membranes. Disruption of the SCP160 gene is not lethal but results in cells of decreased viability, abnormal morphology and increased DNA content. This phenotype is not reversible by transformation with a plasmid carrying the wild-type gene. Crosses of SCP160 deletion mutant strains among each other or with unrelated strains lead to irregular segregation of genetic markers. Taken together the data suggest that the Scp160 protein is required during cell division for faithful partitioning of the ER–nuclear envelope membranes which in S. cerevisiae enclose the duplicated chromosomes.     

Approaches for Discrete Alternative Multiple Criteria Problems for Different Types of Criteria

In this paper we address two classes of sdiscrete alternative multiple criteria decision making problems: problems in which ordinal and cardinal criteria are simultaneously involved and problems in which only cardinal criteria are involved. We suggest variations of our previously developed ordinal criteria approach [5] and we test the approaches on randomly generated problems. Our evaluation criteria are: the capability of the approach to find a highly preferred alternative and the amount of information required of a decision maker.     

A hierarchical procedure for multi-skilled sales force spatial planning

Marketing and sales comprise an important part of a company's core processes. We study this core component in a very large corporation in the process industry. This company has thousands of employees worldwide involved in sales and marketing activities. The optimal utilization of this large workforce is rigorously analyzed in this paper. We develop a hierarchical procedure including a sequence of mathematical models to address workload determination and sales force planning within the company. In particular, our sequence of models determines: (a) the optimal number of visits to each of the existing customers with the goal of retaining them; (b) the optimal number of employees with different kinds of skills for satisfying the workload obtained using model (a) including the time to hunt for new customers; and (c) the optimal way of providing the workforce calculated in part (b) (i.e., optimal strategies for hiring, relocation or dismissal of current workforce). Moreover, we face some nonlinear constrained integer programming problems in our sequence of mathematical models which are not easily solved by commercial software. We develop our own efficient methods for solving such problems optimally.     

An Automated Network Generation Procedure for Routing of Unmanned Aerial Vehicles (UAVs) in a GIS Environment

In this paper, the problem of creating a network to facilitate planning of an air reconnaissance mission is investigated. A comprehensive review of the literature shows that limited work has been done on the design of such networks in a hostile environment and that little research has accounted for terrain information. Ideally, in any routing problem a sample network is used as reference to determine paths to achieve a specified goal. The objective of this paper is to propose an automated generalized procedure developed within a Geographical Information System environment, to identify the nodes and links of a network based on the topographic information of the enemy terrain. This information is made available in the form of a Triangulated Irregular Network (TIN). Inputs to the network generation process include (I) a user-specified threshold altitude value to avoid radar detection and terrain collisions, (II) a specification of the node density in the study area and (III) the minimum/maximum lengths for the links in the desired network. The generated networks are evaluated based on traditional network analysis measures and on the area covered based on a visibility analysis. The methodology is particularly useful for air mission of Unmanned Aerial Vehicles (UAVs) and robot motion planning. As an example, a case study using elevation data from the state of Colorado is presented.