The Subtour Centre Problem

The subtour centre problem is the problem of finding a closed trail S of bounded length on a connected simple graph G that minimises the maximum distance from S to any vertex ofG. It is a central location problem related to the cycle centre and cycle median problems (Foulds et al., 2004; Labbé et al., 2005) and the covering tour problem (Current and Schilling, 1989). Two related heuristics and an integer linear programme are formulated for it. These are compared numerically using a range of problems derived from tsplib (Reinelt, 1995). The heuristics usually perform substantially better then the integer linear programme and there is some evidence that the simpler heuristics perform better on the less dense graphs that may be more typical of applications

Insertion Heuristics for Central Cycle Problems

A central cycle problem requires a cycle that is reasonably short and keeps a the maximum distance from any node not on the cycle to its nearest node on the cycle reasonably low. The objective may be to minimise maximumdistance or cycle length and the solution may have further constraints. Most classes of central cycle problems are NP-hard. This paper investigates insertion heuristics for central cycle problems, drawing on insertion heuristics for p-centres [7] and travelling salesman tours [21]. It shows that a modified farthest insertion heuristic has reasonable worstcase bounds for a particular class of problem. It then compares the performance of two farthest insertion heuristics against each other and against bounds (where available) obtained by integer programming on a range of problems from TSPLIB [20]. It shows that a simple farthest insertion heuristic is fast, performs well in practice and so is likely to be useful for a general problems or as the basis for more complex heuristics for specific problems

Data Envelopment Analysis Models of Investment Funds

Publisher PD

Integration effects of pylon geometry on a high-wing transport airplane

An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the installation effects of a series of pylons that had differing cross-sectional shapes on the pressure distributions and aerodynamic characteristics of a 1/24-scale high wing transport. The tests were conducted at Mach numbers at 0.70 and 0.80 at angles of attack from -3 degrees to 4 degrees with the pylons tested at various toe angles between 5 degrees inboard and 5 degrees outboard. Results of this study indicate that the installed drag was lowest for the pylons with a compression pylon type design which kept the flow under the wing in the pylon/wing junction comparable to the clean wing velocities

Examining the Impact of California\u27s Medical Marijuana Program on Public Health

The debate surrounding marijuana legalization has increased its popularity in recent years, as the state of California seriously considers the complete legalization of the substance for those ages 21 and over. This would make California the first government in recorded history to regulate the cultivation and sale of marijuana on a commercial level. Advocates back the economic positives concerning high tax revenues, but those opposed argue that the dangers associated with public health greatly outweigh any monetary gain. The present study attempts to reveal the possible public health concerns, even potential benefits, caused by marijuana use and its distribution. Specifically, measures of California’s Medical Marijuana Program will be assessed on the total number of drug treatment admissions in each county, taking into account treatment type and which type of drug is primarily responsible for said admissions. Findings reveal influences by both gateway and substitution effects, creating both positive and negative correlations throughout the field of public health. The influences of intangible variables, like that of the black market, make the results difficult to generalize. However, significant correlations can be found among specific health factors, like Heroin use, Crack/Cocaine use, and Residential Treatment

Planning for geographical allocation of rural development program resources in the uplands of the Province of Antique, Philippines

A problem involving geographical allocation of resources evolved over about ten years from 1975 to 1984 in the context of the Antique Upland Development Program (AUDP) in the Province of Antique, Philippines. The AUDP was a program initiated, planned, and implemented by the local government and targeted to the upland population of the province. Parallel to the evolution of the problem, a set of maps were developed in response to a succession of planning operations in the province. Early planning operations did not provide much guidance for the use of map-based information in the planning process. One later planning operation, the Local Resources Management (LRM) project, provided much greater guidance in the use of map-based information and more clearly defined the place of geo graphical analysis in the planning process. The LRM embodied a change from previous development models. The most notable change was a focus on specific poverty groups and the need to both address their basic human needs and involve the groups directly in the planning process. The LRM project approached development in a manner similar to the AUDP and specifically recognized the role of local governments in development planning. One of the tasks of local government, especially the province, was to identify priority poverty groups for inclusion in the development process, and to specify where, geographically, project resources should be concentrated. This study documented the historical developments of the AUDP, the map-based information on the province, and the planning context to analyze the place of geographical analysis in the planning process at the local government level in the Philippines. From the map-based information developed in the province and the planning criteria embodied in the LRM, this study first analyzed the upland geographical patterns in the province, especially the patterns of population distribution, and then formulated a framework for making decisions on the geographical allocation of AUDP resources. Based on experiences in the planning operations of the province and the LRM planning approach, a general set of guidelines for conducting geographical analysis in local government planning operations was formulated

The Experiences of a Rural Mississippi Mathematics Teacher: A Case Study

This study investigates my experiences as a rural Mississippi secondary mathematics teacher. The culture surrounding accountability testing and rural education as well as student perceptions of my mathematics instruction and classroom management were investigated. With recent educational legislation such as the No Child Left Behind Act of 2001, teachers and students are experiencing education differently than teachers and students of the past. Through this basic interpretive case study, I sought to increase the limited research surrounding student perceptions of rural mathematics instruction and accountability testing and to provide a descriptive image of teaching in this rural school. The students, administrators, and test-based accountability were shown to have strong influences on mathematics instruction. The use of math manipulatives, competitive games, and reward systems were perceived as beneficial to many students. Some students? perceptions regarding cooperative learning and technological implementations were not as definitive or as positive as the engaging instruction. Disruptive behaviors, poor classroom management, administrative organization, and standardized test preparations caused instructional time to be lost. Inconsistencies in scheduling, instruction, and management were shown to influence the instructional climate. Teacher preparedness to teach students of differing cultural, ethnic, and economic backgrounds was shown to create various challenges in classroom instruction. The rural characteristics of this school minimized course offerings, increased individualized instruction, and presented monetary issues that were challenging and also beneficial to the students and teachers. As for accountability testing, teachers and administrators in this school tended to accept the testing culture with some disagreements, while students believed state assessments motivated them to perform better in class despite increasing certain levels of anxiety before and after the assessments. The implications of this study describe how teaching and learning in this school were filled with obstacles both teachers and students had to overcome in order to improve student achievement. Several recommendations for this school, future educators, and state and national departments of education are provided. Finally, this study provides an in depth look at the small details that make teaching in this rural school an everyday challenge

Star formation in infrared bright and infrared faint starburst interacting galaxies

Short wavelength IUE spectra of Arp 248b and UGC 8315N are combined with optical spectra and interpreted using a combination of spectrum synthesis and spectral diagnostics to place constraints on the massive star populations of the central regions of these galaxies and to deduce information about the star formation histories in the last 10(exp 8) years. The authors find that both galaxies have substantial fractions of their optical light coming from massive stars and that Arp 248b may be dominated in the UV by WR stars. The UV spectra are dominated by radiation from evolved massive stars and the authors place and age on the burst in Arp 248b of a few tens of millions of years

I Cannot Sing You Here, But For Songs of Where: Contemporary Alt-folksong and Articulations of Place

This practice-based research questions the potential defining characteristics and status of contemporary alt-folksong and its role(s) in the articulation of place through a collection of twelve original songs with accompanying written research. The thesis relates the term ‘place’ to the notion of subjectivity, autobiography and the performance of identity as they relate to geographic experience (Tuan 1997; Agnew 2005). Place is addressed from the perspective of a subject both re- and dis-located, and as such, diasporic neurosis concerning home and authenticity leads to a focus on aspects of place related to my past (Shetland), heritage (Ireland), present (Cornwall), and ‘in between’ (Augé 1995). Methodologically, songs respond to, and inform, written/ read/ listened research, with a ‘diarist’ mode of writing linking audio and text. Songs are generated through engagement with these research methods, and through field trips and recordings, influencing the directions of page-based enquiry. Early chapters draw on theories of Popular Music (Moore 1993; Eisenberg 2005) and Postmodernism (Jameson 1998), but also look to ethnomusicology of Folksong (Gammon 2008; Boyes 1993), and interviews with practitioners (Hayman 2011; Collyer 2010), characterising the relationship between traditional music and contemporary Alt-folk. Chapter 2 introduces psychoanalytic theory (Lacan 1977; Minsky 1998) in locating the three places within development of the subject. Each place is subsequently addressed respectively through appropriation of Lacan’s Imaginary, Symbolic and Real as a means of investigating the subject’s relationship to each. Chapter 3 discusses autobiographic theory (Marcus 1994; Anderson 2001), assessing the value of such a songwriting method, and aspects of musical ‘meaning’ (Small 1998; Moore 1993). Chapter 4 investigates the use of production/recording technologies as themselves sources of meaning (Doyle 2005; Barthes 2000). Conclusions, in songs and text, work towards articulation of the ‘outside’ nature of the itinerant in these aspects of (non)place, and the capacity of Alt-folksong to voice this state