Integer k-matching preclusion of graphs

As a generalization of matching preclusion number of a graph, we provide the (strong) integer $k$-matching preclusion number, abbreviated as $MP^{k}$ number ($SMP^{k}$ number), which is the minimum number of edges (vertices and edges) whose deletion results in a graph that has neither perfect integer $k$-matching nor almost perfect integer $k$-matching. In this paper, we show that when $k$ is even, the ($SMP^{k}$) $MP^{k}$ number is equal to the (strong) fractional matching preclusion number. We obtain a necessary condition of graphs with an almost-perfect integer $k$-matching and a relational expression between the matching number and the integer $k$-matching number of bipartite graphs. Thus the $MP^{k}$ number and the $SMP^{k}$ number of complete graphs, bipartite graphs and arrangement graphs are obtained, respectively.Comment: 18 pages, 5 figure

Derivation of logic programs

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Complete Issue 7(4)

Complete digitized issue (volume 7, issue 4, May 1970) of Speaker & Gavel

Ethnic Party Bans and Civil Unrest: a Measurement Modeling Approach to Predicting Effects of Constitutional Engineering

Political representation through exclusively ethnic parties has long been thought to create, or enforce, social cleavages leading to conflict. To gain support and mobilize ethnic constituents, ethnic party leadership has incentive to exaggerate differences between, or even antagonize, members of other ethnic groups through the process of ethnic outbidding. Classic political theory cautions that the exclusive nature of ethnic parties can also produce a dangerous zero sum game between ethnic groups that cannot be solved by compromise via democratic institutions. Several institutional solutions have been proposed to counter the problem of instability ethnic divisions create for new democracies, encountering varying levels of success. Constitutional ethnic party bans are designed with the intention of coercing ethnic groups to form inclusive, multiethnic political parties. Party membership, then, takes on a national, rather than communal, character, which is thought to prevent extremism and encourage moderate political parties. Opponents of this method of party regulation argue that prohibiting ethnic groups from forming parties obstructs advancement of interests exclusive to the ethnic group and that this practice is especially repressive for ethnic minorities. The theory I present in this dissertation makes the case that ethnic party bans, in the form of constitutional party regulations with spatial distribution requirements, instead prevent majority ethnic groups from resorting to extremism by restricting parties to compete in elections only when the party has diverse membership. To garner support across ethnic cleavages, through a kind of party-level federalism, party leaders are compelled to moderate political platforms in order to form winning coalitions. I argue that this institutional arrangement is not only effective at reducing conflict, but that the design is more stabilizing than power-sharing or proportional representation. To date, there is no consensus on whether the risk of unrest is heightened by ethnic party competition or subsequently dampened by the banning of ethnic party participation in politics. Recent empirical inquiries into the relationship between ethnic parties, or banned ethnic party activity, and conflict have returned contradictory results. Some of the discrepancy in findings can be attributed to differing approaches to research design. In particular, in Ishiyama\u27s 2011 study his mixed findings indicate that in certain statistical models ethnic parties are more prone to conflict whereas utilizing alternative modeling strategies, there is no apparent relationship. I argue that the problem requires a deeper inquiry into measurement attributes of the data which can offer insight into the selection of appropriate modeling techniques. My research deals with this measurement problem by utilizing alternating least squares optimal scaling (ALSOS) regression to effectively transform the ordinal dependent variable to its least biased linear form. As an added attempt to reduce endogeneity, I employ causal inference techniques to stratify a sample of most similar cases between ethnic groups with parties, without parties, and those who have been banned from party operation. This scaling solution will both improve this particular model of ethnic conflict and demonstrate the value of ALSOS regression in myriad social science applications. The analysis follows with discussion of several cases of constitutional ethnic party bans, examining the specific features of the institution that prove most useful. I find that constitutional ethnic party bans are an effective tool in the prevention of ethnic outbidding. Ethnic groups banned from forming exclusively ethnic parties engage in lower levels of unrest as compared to groups with ethnic parties. I also show that bans with spatial distribution requirements work well to facilitate minority ethnic group representation within multiethnic parties and that bans are less effective in countries with already well-established ethnic parties

Dielectric-barrier discharge plasma actuators for turbulent friction-drag manipulation via spanwise oscillations

Ein Plasmaaktuator wird über instationäre Betriebsmodi angesteuert, um wandnahe Fluidoszillationen zu erzeugen. Das Ziel ist es, spannweitig oszillierende Wände zugunsten einer Verringerung des turbulenten Reibungswiderstands nachzuahmen. Da der Aktuator keine beweglichen Teile besitzt, könnte er sich als nicht-mechanischer Ersatz der oszillierenden Wand eignen. Die Kombination von Betriebsmodus und zugrundeliegender Elektrodenanordnung ist eine Neuerung, welche die spannweitige Homogenität der Strömung solcher virtuellen Wandoszillationen verbessert. Die mechanische Charakterisierung wird mittels eines planaren Feldmessverfahrens durchgeführt, um sowohl die induzierten Strömungstopologien als auch die Effekte von Volumenkraft und „virtueller Wandgeschwindigkeit“, d.h. Reaktion des Fluids, aufzuzeigen. Daraus wird zur Bewertung und Optimierung der Leistungsfähigkeit des Aktuators ein universelles Diagramm hinsichtlich aktuatorspezifischer Parameter abgeleitet. Da die berechnete Volumenkraft die Art der Kraftausübung gut widerspiegelt, kann diese modellhaft zu verbesserten numerischen Simulationen der Aktuatorik dienen. Ferner wird eine neue Vorgehensweise für die Bestimmung der elektrischen Leistung von Aktuatoren mit mehreren Hochspannungselektroden bereitgestellt, welche die potenzielle Abschätzung des Nettogewinns in aktiven Kontrollszenarien ermöglicht. Zuletzt wird die unmittelbare Auswirkung der oszillatorischen Kraftausübung auf den Reibungswiderstand in der Querebene einer voll entwickelten turbulenten Kanalströmung mittels einer stereoskopischen Feldmesstechnik untersucht. Im Wesentlichen verbleibt die Strömung im sich entwickelnden Stadium und erfährt auf dem Aktuator eine Erhöhung des Reibungswiderstands, während sich dieser stromab des Aktuators verringert

Concurrent Participation in Federally-Funded Welfare Programs and Empowerment toward Economic Self-Sufficiency

The purpose of this research was to determine the odds for low-income households to become and remain economically self-sufficient as a result of participating in federallyfunded welfare programs. An evaluation in nature, this study assessed the merits and shortcomings of federally-funded welfare programs. Using the public-use version of the 2008 Survey of Income and Program Participation (SIPP) Panel, this quasi-experimental investigation compartmentalized 4,216 low-income households into two groups: an intervention group (n = 2,436) and a comparison group (n = 1,780). Households in the intervention group received one or more federal means-tested welfare benefits for the most part of the 2008-2013 quinquennium. By contrast, those in the comparison group— although eligible for these benefits—did not receive them. Based on the premises of the theory of policy design and social construction, the culture of poverty theory, the racial classification model, and the social control thesis, the following two hypotheses were formulated: (1) Low-income households who receive one or more lower-tier federal means-tested benefits will be less likely to attain and maintain economic self-sufficiency vii than their counterparts who do not participate in federal welfare programs and (2) Lowincome households that enroll in more welfare programs will have worse self-sufficiency outcomes than their counterparts that participate in fewer programs. The survey respondents were measured repeatedly over a 56-month period to assess whether welfare receipt impacts their household income steadily beyond 150 percent of the federal poverty level, after controlling for known predictors. Findings from binomial logistic regression displayed medium effect sizes indicating that participation in public assistance did decrease the likelihood of attainment and maintenance of economic self-sufficiency among low-income American households. These findings were interpreted within the context of pre-existing differences that may have existed between the intervention group and the comparison group which were not accounted for in the multivariate analysis. Macro-implications of these findings for poverty and social welfare stakeholders were discussed