bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral-method algorithm for modeling dispersion of acoustic modes in elastic cylindrical structures
Authors: Karpfinger Florian , Valero Henri-Pierre , Gurevich Boris , Bakulin Andrey , Sinha Bikash
Published: June 2010

A new spectral-method algorithm can be used to study wave propagation in cylindrically layered fluid and elastic structures. The cylindrical structure is discretized with Chebyshev points in the radial direction, whereas differentiation matrices are used to approximate the differential operators. We express the problem of determining modal dispersions as a generalized eigenvalue problem that can be solved readily for all eigenvalues corresponding to various axial wavenumbers. Modal dispersions of guided modes can then be expressed in terms of axial wavenumbers as a function of frequency. The associated eigenvectors are related to the displacement potentials that can be used to calcu-late radial distributions of modal amplitudes as well as stress components at a given frequency. The workflow includes input parameters and the construction of differentiation matrices and boundary conditions that yield the generalized eigenvalue problem. Results from this algorithm for a fluid-filled borehole surrounded by an elastic formation agree very well with those from a root-finding search routine. Computational efficiency of the algorithm has been demonstrated on a four-layer completion model used in a hydrocarbon-producing well. Even though the algorithm is numerically unstable at very low frequencies, it produces reliable and accurate results for multilayered cylindrical structures at moderate frequencies that are of interest in estimating formation properties using modal dispersions.
Euler deconvolution in the presence of sheets with finite widths
Authors: Thurston Jeff
Published: June 2010

Euler deconvolution of magnetic fields, induced by sheets with nonnegligible widths, provides source-location estimates that are biased away from the true locations. I have derived formulas for these biases and used the equations to model diffuse solution patterns that are owing to the interplay between integer structural indices and finite sources. These patterns closely match solutions deconvolved from aeromagnetic data over northern Canada. Motivated out of the necessity that complete harmonics be integral degreed, I have investigated and discovered the ineffectiveness of noninteger structural indices in remediating the aforementioned biases. In fact, real numbers impart similar errors to multiple Euler solutions, causing ensembles of estimated origin loci to reside below the middle of the tops of wide sheets. I have devised an approach requiring the inclusion of a term in the Euler deconvolution kernel whose independent variable is the second horizontal derivative of the total field, and whose partial slope (to be solved) is the sheet width. This approach is appropriate only if the thickness does not exceed the depth. However, precision could be sacrificed in favor of accuracy because of the presence of the second derivative. The application to aeromagnetic data over a diabase dike in northern Canada yields a depth effectively coincident with a drilling depth.
The mechanical function of linked muscles in the guinea fowl hind limb
Authors: Ellerby David J. , Marsh Richard L.
Published: June 2010

Although mechanical linkages between the proximal and distal limb are present in a range of species, their functional significance is unknown. We have investigated the mechanical function of the flexor cruris lateralis pars pelvica (FCLP), flexor cruris lateralis pars accessoria (FCLA) and gastrocnemius intermedia (GI), a system of linked muscles spanning proximal and distal limb segments in the guinea fowl (Numida meleagris) hind limb. The FCLP, which is in the anatomical position of a hamstring muscle, is the primary component of the linkage. It is connected to the distal femur via the FCLA, the tarsometatarsus via the tendon of insertion of the GI and the common Achilles tendon, and the tibiotarsus via a distal tendon of insertion. The FCLP may, therefore, potentially exert moments at the hip, knee and ankle joints depending on the joint angles and the relative states of activation in the three muscles. Evidence presented here suggests that the GI and FCLA act as actively controlled links that alter distal action of the FCLP. The FCLP and GI are coactive in the late swing and early stance phases of the stride, forming a triarticular complex, and likely act together to resist and control ankle flexion immediately after foot-down in addition to providing hip extension and knee flexion moments. The FCLP and FCLA are coactive from mid-through to late stance, acting together as a uniarticular hip extensor. Available evidence suggests that this role of the FCLP and FCLA is of increased importance in inclined running and accelerations. This linkage between a proximal muscle and alternate distal connections allows for functional flexibility, both in terms of the site at which the muscle exerts force and the nature of the muscle's mechanical function. The interactions generated between the proximal and distal limb by linkages of this type suggest that less emphasis should be placed on the distinct functional roles of specific anatomical classes of muscle within proximal and distal limb segments.
Chirping response of weakly electric knife fish (Apteronotus leptorhynchus) to low-frequency electric signals and to heterospecific electric fish
Authors: Dunlap K. D. , DiBenedictis B. T. , Banever S. R.
Published: June 2010

Brown ghost knife fish (Apteronotus leptorhynchus) can briefly increase their electric organ discharge (EOD) frequency to produce electrocommunication signals termed chirps. The chirp rate increases when fish are presented with conspecific fish or high-frequency (700–1100 Hz) electric signals that mimic conspecific fish. We examined whether A. leptorhynchus also chirps in response to artificial low-frequency electric signals and to heterospecific electric fish whose EOD contains low-frequency components. Fish chirped at rates above background when presented with low-frequency (10–300 Hz) sine-wave stimuli; at 30 and 150 Hz, the threshold amplitude for response was 1 mV cm–1. Low-frequency (30 Hz) stimuli also potentiated the chirp response to high-frequency (∼900 Hz) stimuli. Fish increased their chirp rate when presented with two heterospecific electric fish, Sternopygus macrurus and Brachyhypopomus gauderio, but did not respond to the presence of the non-electric fish Carassius auratus. Fish chirped to low-frequency (150 Hz) signals that mimic those of S. macrurus and to EOD playbacks of B. gauderio. The response to the B. gauderio playback was reduced when the low-frequency component (<150 Hz) was experimentally filtered out. Thus, A. leptorhynchus appears to chirp specifically to the electric signals of heterospecific electric fish, and the low-frequency components of heterospecific EODs significantly influence chirp rate. These results raise the possibility that chirps function to communicate to conspecifics about the presence of a heterospecific fish or to communicate directly to heterospecific fish.
Motor patterns associated with crawling in a soft-bodied arthropod
Authors: Simon Michael A. , Fusillo Steven J. , Colman Kara , Trimmer Barry A.
Published: June 2010

Soft-bodied animals lack distinct joints and levers, and so their locomotion is expected to be controlled differently from that of animals with stiff skeletons. Some invertebrates, such as the annelids, use functionally antagonistic muscles (circumferential and longitudinal) acting on constant-volume hydrostatics to produce extension and contraction. These processes form the basis for most theoretical considerations of hydrostatic locomotion in organisms including larval insects. However, caterpillars do not move in this way, and their powerful appendages provide grip independent of their dimensional changes. Here, we show that the anterograde wave of movement seen in the crawling tobacco hornworm, Manduca sexta, is mediated by co-activation of dorsal and ventral muscles within a body segment, rather than by antiphasic activation, as previously believed. Furthermore, two or three abdominal segments are in swing phase simultaneously, and the activities of motor neurons controlling major longitudinal muscles overlap in more than four segments. Recordings of muscle activity during natural crawling show that some are activated during both their shortening and elongation. These results do not support the typical peristaltic model of crawling, but they do support a tension-based model of crawling, in which the substrate is utilized as an anchor to generate propulsion.
Effects of wing deformation on aerodynamic forces in hovering hoverflies
Authors: Du Gang , Sun Mao
Published: June 2010

We studied the effects of wing deformation on the aerodynamic forces of wings of hovering hoverflies by solving the Navier–Stokes equations on a dynamically deforming grid, employing the recently measured wing deformation data of hoverflies in free-flight. Three hoverflies were considered. By taking out the camber deformation and the spanwise twist deformation one by one and by comparing the results of the deformable wing with those of the rigid flat-plate wing (the angle of attack of the rigid flat-plate wing was equal to the local angle of attack at the radius of the second moment of wing area of the deformable wing), effects of camber deformation and spanwise twist were identified. The main results are as follows. For the hovering hoverflies considered, the time courses of the lift, drag and aerodynamic power coefficients of the deformable wing are very similar to their counterparts of the rigid flat-plate wing, although lift of the deformable wing is about 10% larger, and its aerodynamic power required about 5% less than that of the rigid flat-plate wing. The difference in lift is mainly caused by the camber deformation, and the difference in power is mainly caused by the spanwise twist. The main reason that the deformation does not have a very large effect on the aerodynamic force is that, during hovering, the wing operates at a very high angle of attack (about 50 deg) and the flow is separated, and separated flow is not very sensitive to wing deformation. Thus, as a first approximation, the deformable wing in hover flight could be modeled by a rigid flat-plate wing with its angle of attack being equal to the local angle of attack at the radius of second moment of wing area of the deformable wing.
Partition of aerobic and anaerobic swimming costs related to gait transitions in a labriform swimmer
Authors: Svendsen Jon C. , Tudorache Christian , Jordan Anders D. , Steffensen John F. , Aarestrup Kim , Domenici Paolo
Published: June 2010

Members of the family Embiotocidae exhibit a distinct gait transition from exclusively pectoral fin oscillation to combined pectoral and caudal fin propulsion with increasing swimming speed. The pectoral–caudal gait transition occurs at a threshold speed termed Up–c. The objective of this study was to partition aerobic and anaerobic swimming costs at speeds below and above the Up–c in the striped surfperch Embiotoca lateralis using swimming respirometry and video analysis to test the hypothesis that the gait transition marks the switch from aerobic to anaerobic power output. Exercise oxygen consumption rate was measured at 1.4, 1.9 and 2.3 L s–1. The presence and magnitude of excess post-exercise oxygen consumption (EPOC) were evaluated after each swimming speed. The data demonstrated that 1.4 L s–1 was below the Up–c, whereas 1.9 and 2.3 L s–1 were above the Up–c. These last two swimming speeds included caudal fin propulsion in a mostly steady and unsteady (burst-assisted) mode, respectively. There was no evidence of EPOC after swimming at 1.4 and 1.9 L s–1, indicating that the pectoral–caudal gait transition was not a threshold for anaerobic metabolism. At 2.3 L s–1, E. lateralis switched to an unsteady burst and flap gait. This swimming speed resulted in EPOC, suggesting that anaerobic metabolism constituted 25% of the total costs. Burst activity correlated positively with the magnitude of the EPOC. Collectively, these data indicate that steady axial propulsion does not lead to EPOC whereas transition to burst-assisted swimming above Up–c is associated with anaerobic metabolism in this labriform swimmer.
Neuropeptides in theDrosophilacentral complex in modulation of locomotor behavior
Authors: Kahsai Lily , Martin Jean-René , Winther Åsa M. E.
Published: June 2010

The central complex is one of the most prominent neuropils in the insect brain. It has been implicated in the control of locomotor activity and is considered as a pre-motor center. Several neuropeptides are expressed in circuits of the central complex, and thus may be modulators of locomotor behavior. Here we have investigated the roles of two different neuropeptides, Drosophila tachykinin (DTK) and short neuropeptide F (sNPF), in aspects of locomotor behavior. In the Drosophila brain, DTK and sNPF are expressed in interneurons innervating the central complex. We have directed RNA interference (RNAi) towards DTK and sNPF specifically in different central complex neurons. We also expressed a temperature-sensitive dominant negative allele of the fly ortholog of dynamin called shibirets1, essential in membrane vesicle recycling and endocytosis, to disrupt synaptic transmission in central complex neurons. The spontaneous walking activity of the RNAi- or shibirets1-expressing flies was quantified by video tracking. DTK-deficient flies displayed drastically increased center zone avoidance, suggesting that DTK is involved in the regulation of spatial orientation. In addition, DTK deficiency in other central complex neurons resulted in flies with an increased number of activity–rest bouts. Perturbations in the sNPF circuit indicated that this peptide is involved in the fine regulation of locomotor activity levels. Our findings suggest that the contribution of DTK and sNPF to locomotor behavior is circuit dependent and associated with particular neuronal substrates. Thus, peptidergic pathways in the central complex have specific roles in the fine tuning of locomotor activity of adult Drosophila.
Using a Spreadsheet for Active Learning Projects in Operations Management
Authors: Gardner Leslie
Published: June 2010

This paper describes a set of active learning strategies using or supplemented by spreadsheets that enables students to learn the logic behind software packages, to gain experience using a spreadsheet to solve real problems, to have a more clear view of the dynamics of business systems, and to learn to organize and manage small scale projects.
An Interactive Spreadsheet-Based Tool to Support Teaching Design of Experiments
Authors: Enns S. T.
Published: June 2010

This paper describes an interactive spreadsheet-based tool that can be used to generate data representative of the type that might be obtained running a structured set of experiments. The purpose of this tool is to help the user experience the iterative nature of design and analysis of experiments. The tool supports quick and simple generation of data for one and two-factor problems. The underlying relationships are based on queuing approximations for a single-stage batch production environment. Factor levels are related to product lot sizes and the response is assumed to be average lot flowtimes. Variability due to replication is emulated by sampling from a statistical distribution. Statistical software packages can be used to generate linear or quadratic models from the results generated. Analysis can include the examination of main and interaction effects or the optimization of lot sizes to minimize flowtimes.
Modeling Multi-Objective Multi-Stakeholder Decisions: A Case-Exercise Approach
Authors: Feng Tianjun , Keller L. Robin , Zheng Xiaona
Published: June 2010

The multi-objective multi-stakeholder decision modeling methodology is an effective way to describe and aid context-rich idiosyncratic organizational decision making situations that traditional single attribute decision methodologies can not tackle. The purpose of this paper is to demonstrate how to teach students this methodology as a decision making tool to analyze real-life decision problems using two business decisions as examples (the StarKist decision and the Home Depot case). In particular, we discuss the specific skills students are expected to learn, such as dynamic sensitivity analysis, and typical student questions and errors during case discussion. This methodology has been taught successfully in decision analysis courses both for MBA (including full-time MBA students, business and health care executive MBA students) and undergraduate students.
Teaching Pricing and Revenue Optimization
Authors: Phillips Robert
Published: June 2010

Pricing and revenue optimization, defined as the formulation and solution of tactical pricing decisions using constrained optimization, is becoming an increasingly popular subject to be taught at the MBA level. Perhaps the best-known example of pricing and revenue optimization is revenue management whereby airlines, hotels, and other companies seek to maximize operating contribution by opening and closing fare classes. However, a number of other important business problems including markdown management, dynamic pricing for e-commerce, and customized pricing are also parts of pricing and revenue optimization. This article gives an overview of the field for those who are considering teaching the topic to MBA students. I outline the scope of the area, describe specific topics that can be included, present a sample syllabus and provide some guidance based on my own experience and links to additional resources.
Experiences Using Thematic Assignments in an Undergraduate Management Science Course
Authors: Grinde Roger B. , Kammermeyer Jill A.
Published: June 2010

This paper presents a theme-based approach for individual and group assignments in an undergraduate Management Science course. We have been using this approach since Fall 2001, with three different themes. In Fall 2001 we used a “generic” entertainment venue theme. For Spring 2002 we focused the “venue” theme, took advantage of current events, using the Winter Olympics as a basis for the assignments. In Fall 2002 we switched to Socially Responsible Investing as the theme throughout the term. The use of a theme to link assignments throughout the term is a middle ground between cases (instructor-specified) and student-defined projects. The aim was to combine some of the best features of both approaches to the active learning component in the course. This paper discusses our approach, outlines the assignments, and provides student feedback regarding their perceptions as to the effectiveness of the assignments.
Elements of End-User Software Engineering
Authors: Scheubrein Ralph
Published: June 2010

Today many end-users implement software tools on their own due to their high, general computer literacy and the increased user-friendliness of the software. The most popular and ubiquitous software packages to implement such personal productivity tools for analytical purposes are spreadsheets. A general problem is that a typical knowledge worker in the role of an end-user does not have explicit training in software engineering. Therefore, in this article some aspects of software engineering in general and spreadsheet engineering in particular are discussed. Based on this discussion several guidelines for implementing spreadsheet-based tools are given. Applying these guidelines helps to design spreadsheet-based tools that can be easily reused, extended, and shared with other users. A case study illustrates how to use Microsoft Excel to implement a tool which is in compliance with these guidelines. The case study is designed as an introduction for MBA students on how to implement spreadsheet-based analytical tools.
Beer in the Classroom: A Case Study of Location and Distribution Decisions
Authors: Köksalan Murat , Salman F. Sibel
Published: June 2010

We discuss our experience in using a case study of location and distribution decisions in undergraduate and MBA level Management Science and Operations Research courses. The Anadolu Efes case introduces a multiperiod strategic planning problem that requires the optimization of brewery location and capacity expansion decisions in addition to malt and beer distribution decisions. The case has been used effectively to improve students' skills on modeling, solving and interpreting the outputs of linear programs and mixed integer programs. The case material is based upon past collaboration with Efes on a number of projects. The problem is a hypothetical one but is similar to problems Efes has been facing. Efes' real distribution system has been simplified for the purpose of keeping the model size manageable.
Exercises for Teaching the Analytic Hierarchy Process
Authors: Bodin Lawrence , Gass Saul I.
Published: June 2010

In a related paper (Bodin and Gass 2003), we described the basic concepts that we believe must be covered when teaching the Analytic Hierarchy Process (AHP) to MBA students and outlined six exercises that can be used as in-class examples or homework problems. In this paper, we present the details of these exercises and an example of an AHP analysis.
Spreadsheet-Based Professional Modelling
Authors: Thiriez Hervé
Published: June 2010

This paper describes, with reference to several professional models developed by the author, how the use of Excel often allows for a much higher efficiency to cost ratio than more traditional approaches such as specialized packages or the use of development languages.

Used efficiently, and with the assistance of add-ins, Excel may help build models which most people are convinced would demand more sophisticated software. Of course, this often implies the use of elaborate techniques which reduce the negative impact of Excel's natural limits in terms of number of columns, calculation time, bugs, and so on.

There are many other reasons why Excel models are so interesting for business: the interactivity of these models, their reduced development time and cost, their user-friendliness, the positive user/client attitude (the model is not a black box), and the rich graphic possibilities (when the model does not limit itself to standard Excel graphs).
VA-TX Investment Corporation: Credit Card Division
Authors: Keller Christopher M. , Kros John F.
Published: June 2010

The subject matter in the VA-TX case is credit cards. Since almost everyone is familiar with credit cards, the instructor can focus on discussing the included management problems rather than being sidetracked by the intricacies of, say, widget production. The VA-TX case is used to jumpstart basic quantitative business analysis skills. The case uses simple calculations of profits, revenues, and costs. These calculations require an understanding of only simple probabilities and some notion of averages. It also touches on the ideas of a basic definition of risk, tradeoffs, and defining optimality. This case is written for business students and is flexible enough to fit either into an introductory quantitative modeling course, including operations management. The case has been used at both the senior undergraduate level and at the MBA level. The case is particularly useful as a group presentation device and the Teaching Note ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/index.php ) is addressed for instructor interaction with group presentations. Students report the case as challenging and “eye opening” to the concepts of “what if” analysis and the importance of modeling assumptions. A power point slide presentation of this case is provided here ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/VA-TXINFORMS.ppt ). In addition, an Excel model ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/VA-TXSpread1.xls ) with a sample “Starter” ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/index.php#starter1 ) explanation in written form for that model, a writing guide ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/bizcomm.php ) for executive summary style writing, and a sample executive summary ( http://archive.ite.journal.informs.org/Vol4No2/KellerKros/index.php ) for the case are included.
The HSOR Project: Insinuating OR into High School Mathematics Classrooms
Authors: Edwards Thomas G. , Chelst Kenneth R.
Published: June 2010

The field of operations research faces a visibility problem that represents a serious problem in attracting the next generation of operations researchers and in building a base of consumers of operations research studies. A major goal of the initiative described here, the High School Operations Research Outreach (HSOR), is to bring operations research into high school mathematics classrooms. This serves the dual purpose of increasing public awareness of the field of operations research and introducing rich, real-world problem situations to students of high school mathematics. HSOR has attempted to do so by developing a series of classroom materials set in OR contexts and by establishing a cadre of OR professionals who are willing and available to present these materials to groups of high school mathematics teachers.
OR/MS in A New MBA Program
Authors: Ólafsson Snjólfur
Published: June 2010

The University of Iceland launched a two-year executive MBA program in September 2000. The chairman of the program's three-person board (the author) is a professor of OR and together with the director of the program had primary influence on the planning and development of the program. The paper describes how OR/MS (Operations Research/Management Science) was included in the program.

OR was taught to some extent in five courses, in two of eleven compulsory courses and in three of ten elective courses. These courses are described in the paper, which concludes with a discussion.
How can OR/MS Educators Benefit From Creating and Using Taxonomies?
Authors: Reisman Arnold
Published: June 2010

After listing various approaches used over the years to teach OR/MS and quantitative methods and showing sample references for each, this paper suggests that taxonomies, combined with any other approach, can uniquely serve an important educational objective – showing the overall picture of the subject matter. The paper argues for using taxonomies in basic courses and in graduate education as they provide a framework in which the material to be taught, reviewed, or researched can be organized. When made explicit, the framework helps students organize knowledge gained in their own minds. Productivity Analysis (PA) is used to illustrate a taxonomy's educational potential. Lastly, for those interested in so enhancing their approach to teaching, a bibliography of publicly available taxonomies for various theoretic and applied OR/MS sub-disciplines is provided.
Selecting Student Project Teams When it Really Matters: An Optimization-Based Approach Using Internet Resources
Authors: Kirkwood Craig W.
Published: June 2010

This article presents an optimization-based approach to selecting student project teams. This approach is particularly useful when there are more projects available than can be staffed, the assignment of students to teams should be done at the same time that the projects to be conducted are selected, and the quality of the student teams is especially important. I have used this approach to select project teams in our required capstone MBA supply chain management project course for the past three years, and it has both simplified the selection process and improved the quality of the results. The approach also provides an easily understood practical illustration of the value of algebraic optimization modeling methods, and it demonstrates the use of Internet optimization resources. For instructors who need to assign project teams but who are not interested in the details of the optimization model, the approach can be applied as a “decision support system” without requiring the user to understand the specifics of the optimization model.
Bowie Kuhn's Worst Nightmare
Authors: Cochran James J.
Published: June 2010

Students are presented with a narrative concerning the contentious negotiations between Major League Baseball (MLB) franchise owners and the Major League Baseball Players Association (MLBPA) over a new collective bargaining agreement in the early 1980s. Details of the 1981 players' strike, ensuing collective bargaining agreement, and strategy for resuming the interrupted season and facilitating the playoffs are provided. Prestrike win/loss records and number of post-strike scheduled games are provided for each team. This case gives students great insight into the formulation of integer programming problems and interpretation of the resulting optimal solutions; in this case they must formulate constraint satisfaction problems with integer decision variables to assess the advisability of the MLB plan for resuming the season and revising the playoff structure to reflect the games lost to the strike (and the potential for an occurrence of Simpson's Paradox). As such, this case is also unique in its use of optimization to demonstrate a statistical phenomenon. Furthermore, although the case deals with a baseball-related problem, it is relatively self-contained and requires no understanding of how baseball is played, so students who are unfamiliar with the sport will not be seriously disadvantaged.
Teaching Decision Making with Baseball Examples
Authors: Bickel J. Eric
Published: June 2010

Sports examples can be wonderful vehicles for teaching OR/MS concepts. Baseball is particularly well suited to teaching statistics/probability, Markov decision processes, and decision analysis. This paper details a baseball example I developed to teach fundamental decision making skills. This example has been used successfully to teach decision making to undergraduates and graduates in technical and non-technical disciplines. It has also been used effectively in industry for training new MBAs and seasoned executives.
Scheduling a Professional Sports League in Microsoft® Excel: Showing Students the Value of Good Modeling and Solution Techniques
Authors: Birge John R.
Published: June 2010

Scheduling a sports league to minimize travel is a notoriously difficult task involving the coordinated solutions of multiple traveling salesperson problems (TSP) with additional constraints. Good modeling techniques can, however, sometimes reduce these problems to manageable sizes. This paper describes the use of a case based on Major League Soccer(1) that illustrates that an extremely difficult optimization problem can be reduced to a sequential optimization problem that yields a globally minimal travel schedule. Each step of the optimization procedure uses spreadsheet software. The case illustrates TSP solution methodology, column generation techniques, and integer programming formulations.
The Science of Sports: Combining Quantitative Analysis and Sports Applications in an Undergraduate Course
Authors: Willoughby Keith A.
Published: June 2010

I present the development of a one-semester undergraduate course devoted to operations research (O.R.) and statistical methodologies in sports, specifically targeted for first-year collegiate students. In particular, this class explores decision analysis and linear regression using sports as the sole basis of application. Term projects and oral presentations permit student groups the opportunity to investigate specific quantitative applications in this field. Essentially, I endeavor to couple a student's inherent interest in sports with training in basic analytical approaches.
Using Mathematics to Solve Some Problems in Industry
Authors: Stecke Kathryn E.
Published: June 2010

This paper describes how some industrial problems can be solved using relatively simple mathematical models. Models can be used also to provide insight into how industrial system components interact. This paper is useful for master's level students in that it describes what a model is as well as the modeling function. Master's students in engineering and MBAs and Ph.D. students who are interested in solving real industry problems should find this overview of models useful. Different types of industrial problems are discussed. Finally, some models that address industrial problems, such as inventory models, linear programming, network flow, decision analysis, queueing models, and simulation are examined. Future industrial modeling situations are described.
Implementing Dynamic Programs in Spreadsheets
Authors: Raffensperger John F. , Richard Pascal
Published: June 2010

This paper has two purposes: to help explain dynamic programs (DP) to students who have no background in procedural languages, and to quantitatively motivate good spreadsheet designs that can be developed and modified easily. Teachers and practitioners could benefit from using spreadsheets to solve the common problems that are suited to DP. We give examples of several important DPs, implemented in different ways with a spreadsheet.

We further analyze these DPs for their constructive complexity, which is the number of keystrokes required to write a spreadsheet for a given computational task, as a function of the input data. We show that a given DP can be written in several ways, with varying constructive complexity. The implementation can drastically affect the difficulty of writing and modifying a spreadsheet. The different examples demonstrate the value of good spreadsheet design.

Note: Please see supplemental material for the errata to this paper.
Classroom Exercises in IP Modeling: Su Doku and the Log Pile
Authors: Chlond Martin J.
Published: June 2010

Two puzzles are presented and discussed with a view to using them as classroom drill exercises in Integer Program Modeling. Mathematical formulations are presented for each puzzle and working models are offered as a resource for instructors.
On the Use of Integer Programming versus Evolutionary Solver in Spreadsheet Optimization
Authors: Baker Kenneth R. , Camm Jeffrey D.
Published: June 2010

The introduction of the evolutionary solver in Frontline Systems' Premium Solver for Education allows students to use any functions in Excel for modeling optimization problems. As a result, instructors teaching optimization now face a dilemma of how much emphasis to place on “traditional” integer programming versus the unrestricted but heuristic approach of the evolutionary solver. Our goal in this work is to shed some light on the tradeoffs in these two modeling approaches. We discuss some experimental results comparing the two approaches for a number of well-known problem types. We also report some observations of student performance with these two different approaches.
The Bread/Flour/Grain Trading Game: Bidding in and Designing Auction Events
Authors: Teich Jeffrey E. , Wallenius Hannele , Wallenius Jyrki
Published: June 2010

Strategic sourcing and more specifically, e-procurement have become part of standard industry practice in recent years with the use of forward and reverse auction events. Training materials and games to teach participants to bid in and design such events, however, has been limited. In this paper we describe a Bread/Flour/Grain trading game we developed for instructors to use with student groups. We also provide accompanying materials and suggestions for running and debriefing of the game. The game imparts design and bidding experience, which students can then apply to real world auction events. It is appropriate for group sizes ranging from six to sixty.
The Free ISP Model and Spinway, Inc.
Authors: Rolland Erik , Fedotova Daria , Patterson Raymond A.
Published: June 2010

Since 1996, several major free ISP services have been founded in the US and elsewhere, including Spinway, Inc. Spinway's services were offered primarily through, and under the name of, large consumer companies such as Yahoo!, KMart, Costco, Spiegel, Barnes & Noble, Ace Hardware, and NBC among others. By early 2001, the free ISP market had been reduced severely, primarily due to the lack of revenues associated with such “free” services. Spinway, founded in 1998, was a major, and perhaps the largest, free ISP in the US with over 6 million customers at its peak. Spinway folded in December of 2000, and the remains of their services were taken over by Kmart's BlueLight.com. In November of 2002, BlueLight.com was sold to United Online and the ISP services available through BlueLight.com are no longer free. This teaching case discusses the viability of free digital infrastructures, such as Internet Service Providers (ISP). We seek to highlight and learn from the general issues experienced at Spinway and at other ISPs and Internet companies of the time.
The Relationship Between Attitudes and Performance in Business Calculus
Authors: Depaolo Concetta , Mclaren Constance H.
Published: June 2010

Undergraduate business curricula include coursework in both statistics and calculus, subjects that can be daunting to even capable students. This study examines undergraduate business students' attitudes toward and performance in both business statistics and calculus, and determines that after controlling for ability, attitudes play a significant role in performance. Although self-reported attitudes become more positive over the course of the semester, attitudes toward calculus are less positive than those toward statistics, and negative attitudes are related to lower exam scores. For students with no prior calculus background, this relationship between negative attitudes and poor exam performance appears to be particularly strong. The conclusions have implications for increasing learning by improving attitudes.
Getting out of a (Strawberry) Jam: An Introduction to Supply Chain Analysis
Authors: Gan Heng-Soon , Khammuang Kwanniti , Wirth Andrew
Published: June 2010

In order to illustrate how various areas of operations research interact in an actual manufacturing scenario, we propose the use of a strawberry jam-making supply chain model consisting of an inventory partner, a production scheduling partner and a delivery partner. The problem is to minimise the overall supply chain cost consisting of inventory order cost, inventory unit purchasing cost, inventory storage cost, transport booking cost, jam storage cost, delivery travel distance cost and jam arrival earliness and tardiness costs. We report on how we devised and taught this case to First Year Mechanical and Manufacturing Engineering students at the University of Melbourne.
Teaching Data Envelopment Analysis using Applichem—New Perspective on a Popular Operations Case
Authors: Gavirneni Srinagesh
Published: June 2010

This paper reports an innovative use of a popular operations management case to illustrate the usefulness and application of a powerful analysis technique called Data Envelopment Analysis (DEA). DEA is often the only available tool that enables managers to evaluate the relative efficiencies of various business units in the presence of multiple performance measures. Applichem is a case study about a multinational chemical company, with six manufacturing plants located all over the world. The manufacturing plants' efficiencies are highly varied and in the presence of excessive capacity, management is having a difficult time determining which plants must be shut down. This case is often studied from an optimization perspective, with the objective of matching customer demands with plant capacities at the lowest possible cost. The case involves multiple measures of performance (e.g. labor cost, material cost, etc.), which makes it ideal for introducing and demonstrating DEA from a practical perspective. This paper details how such an analysis can be presented in a business classroom.
From Rhetoric to Reality: Business Games as Educational Tools
Authors: Ben-Zvi Tal , Carton Thomas C.
Published: June 2010

This paper discusses business games as teaching tools in Management Science (MS). The discipline's traditional teaching methods, while appropriate for the dissemination of foundational knowledge, cannot provide students with a platform to link abstract concepts and real-world problems. We suggest that business simulation games are an effective way to engage students in MS topics; that they compel students to understand and cope with the ambiguities associated with real-world organizations. Specifically, we discuss our experience with the International Operations Simulation Mark/2000 (INTOPIA), a game designed to channel students into a stream of entrepreneurial decision-making. We employed the game over 12 semesters with approximately 1000 advanced MBA candidates. Our findings indicate that business games represent a novel instructional approach: this pedagogy has a real potential to promote the exchange of new ideas on teaching and learning within and across courses in the MS discipline.
Impaired turnover of autophagolysosomes in cathepsin L deficiency
Authors: Dennemärker Julia , Lohmüller Tobias , Müller Sebastian , Aguilar Stephanie Vargas , Tobin Desmond J. , Peters Christoph , Reinheckel Thomas
Published: June 2010

Some of the phenotypes of mice deficient for the lysosomal cysteine endopeptidase cathepsin L (Ctsl) are characterized by large dysmorphic vesicles in the cytoplasm. Specifically, the heart (dilative cardiomyopathy), the thyroid (impaired thyroglobulin processing) and keratinocytes (periodic hair loss and epidermal hyperproliferation) are affected. We hypothesized that the formation of aberrant vesicles is owing to defects in macroautophagy. Therefore, primary mouse embryonic fibroblasts (MEF), which were derived fromCtsl-/-animals crossed with mice transgenic for the autophagy marker GFP-LC3, were investigated.Ctsl-/-MEF show increased number and size of vesicular structures belonging to the ‘acidic’ cellular compartment and are also characterized by GFP-LC3. Induction of autophagy by nutrient starvation or rapamycin treatment showed no significant impairment of the initiation of autophagy, the formation of autophagosomes or autophagosome-lysosome fusion inCtsl-/-MEF, but co-localization of GFP-LC3 and Lamp1 revealed unusually large autophagolysosomes filled with Lamp1. Furthermore, the soluble lysosomal enzyme cathepsin D was elevated inCtsl-/-MEF. Thus, degradation of autophagolysosomal content is impaired in the absence of Ctsl. This could slow the turnover of autophagolysosomes and result in accumulation of the dysmorphic and ‘acidic’ vesicles that were previously described in the context of the pathological phenotypes ofCtsl-/-mice.
Resveratrol treatment induces redox stress in red blood cells: a possible role of caspase 3 in metabolism and anion transport
Authors: Galtieri Antonio , Tellone Ester , Ficarra Silvana , Russo Annamaria , Bellocco Ersilia , Barreca Davide , Scatena Roberto , Laganà Giuseppina , Leuzzi Ugo , Giardina Bruno
Published: June 2010

Resveratrol, an important phytoalexine found in many plants, has been shown to be significantly effective in the treatment of several pathological conditions such as cancer, coronary heart disease and osteoarthritis. This study focuses on the effects of this drug on human red blood cells. In particular, we have examined the influence of resveratrol on Band 3, the anion exchanger protein, and hemoglobin as a function of the oxygenation-deoxygenation cycle. Moreover, special attention has been given to the metabolic changes imposed by caspase 3 activation. Resveratrol has proved to lower superoxide production, thereby decreasing heme-iron oxidation and saving the reducing power required for met-hemoglobin reduction. Oxygen binding experiments showed that resveratrol interacts with hemoglobin, shifting the T→R conformational transition towards the higher-affinity R state. This might contribute to altering the metabolic balance of the cell through an intensification of the pentose phosphate pathway. Moreover, at high oxygenation levels of the erythrocytic hemoglobin, resveratrol induces a significant activation of caspase 3, the action of which on Band 3 has a strong impact on cellular metabolism and anion transport.
Phosphorylation of caldesmon by myosin light chain kinase increases its binding affinity for phosphorylated myosin filaments
Authors: Sobieszek Apolinary , Sarg Bettina , Lindner Herbert , Seow Chun Y.
Published: June 2010

Phosphorylation of myosin by myosin light chain kinase (MLCK) is essential for smooth muscle contraction. In this study we show that caldesmon (CaD) is also phosphorylatedin vitroby MLCK. The phosphorylation is calcium- and calmodulin (CaM)-dependent and requires a MLCK concentration close to that foundin vivo. On average, approximately 2 mol Piper mol of CaD are incorporated at Thr-626 and Thr-693, with additional partial phosphorylation at Ser-658 and Ser-702. The phosphorylation rate for CaD is 20- to 50-fold slower than that for filamentous myosin; faster relative rates were obtained with CaD added to purified actomyosin or myosin preparations containing endogenous MLCK/CaM complex. Addition of CaM also augmented CaD phosphorylation. We further demonstrate that [32P] labeled CaD binds much more readily to phosphorylated filamentous myosin than to unphosphorylated myosin. For actomyosin, CaD binding affinity doubles after myosin phosphorylation, without a significant change in binding stoichiometry (approx. one CaD per myosin molecule). Unphosphorylated CaD is ineffective in competing with the phosphorylated protein for the binding site(s) on myosin filaments. The ATPase activity of reconstituted actomyosin is inhibited by unphosphorylated CaD, and this inhibition was removed by CaD phosphorylation. Our results suggest that CaD phosphorylation plays a role in modifying actomyosin interactionin vivo, particularly during prolonged muscle activation.
Antiproliferative effects induced by guanine-based purines require hypoxanthine-guanine phosphoribosyltransferase activity
Authors: Garozzo Roberta , Sortino Maria Angela , Vancheri Carlo , Condorelli Daniele Filippo
Published: June 2010

Guanine (GUA), guanosine and GMP exert a marked growth inhibition on the U87 glioma cell line that is not seen with other tested nucleotides, nucleosides and nucleobases. This effect could be replicated in several different human tumoral cell lines. Guanine shows a higher potency than guanosine or GMP, and co-treatments with adenosine or adenine are able to antagonize or revert the antiproliferative effect of guanine. The loss of the guanine effect in a cell line bearing a mutated inactive hypoxanthine-guanine phosphoribosyltransferase (HGPRT), and the decreased potency of GUA in U87 cells silenced for HGPRT transcripts, demonstrates the central role of the intracellular metabolism of GUA for growth-inhibitory effects. Considering the potential application of growth-inhibitory substances in anticancer therapy, knowledge of the molecular mechanism underlying GUA-induced effects encourages studies aimed at defining possible tumoral targets for experimental therapies.