Bounding the total domination subdivision number of a graph in terms of its order

The total domination subdivision number \(\mathrm{sd}_{\gamma _{t}}(G)\) of a graph G is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the total domination number. In this paper we prove that \(\mathrm{sd}_{\gamma_{t}}(G)\leq \lfloor\frac{2n}{3}\rfloor\) for any simple connected graph G of order n≥3 other than K ₄. We also determine all simple connected graphs G with \(\mathrm{sd}_{\gamma_{t}}(G)=\lfloor\frac{2n}{3}\rfloor\).     

Towards pluralistic and grassroots national identity: a study of national identity representation by the Kurdish diaspora on social media

ABSTRACT

This study examines the distinctive roles that social media play for the diasporic Kurds in regard to the political and nationhood process. It attempts to understand how the notion of Kurdayeti [Kurdish nationalism] has been affected by the growth of Kurdish social media. It argues: although the Kurdish political activism has been accelerated by the rise of social media and the ethnic identity discussions have become much more visible, the idea of a unified imagined Kurdish nation has been affected by the existing socio-political fragmentations among the Kurds and transformed into a participatory and pluralistic imagined community.     

“I’m Part of This Family”: How Five Care-Giving Partners of Gay Men Story Their Experiences

This study explores how five care-giving partners of gay men with chronic illness “story” their experiences, or how they construct their experiences in narrative form. Participants, all of whom were recruited with the help of local social service agencies, took part in two in-depth semi-structured interviews intended to invoke their stories as care-giving partners of gay men. Narrative analysis was used to conceptualize the respondents’ experiences. Several themes emerged in the study, many of which arguably related to participants’ real or perceived need to negotiate expressions of homophobia and heterosexism in the context of their care-giving narratives.     

How a Divorcee’s Sexual Life Is Socially Constructed and Understood in the Iranian Culture

Sexual well-being is an important factor in postdivorce adjustment and presents various challenges for divorced women in Iran. With an alarming number of marriages ending in divorce in Iran, the postdivorce sexuality adjustment process has become a major concern. Meanings attached to the sexuality of a divorcee necessitate different adjustment and coping strategies among women. How these meanings are generated, negotiated, and modified in Iranian contexts has yet to be explored. We used a grounded theory approach to analyze the extensive, rich data obtained through sustained interaction with the informants as well as through in-depth individual interviews and focus group discussions. “Sociosexual problems” was found to be one of the main domains in our study. Participants experienced a negative impact from divorce on their sexual lives, including sexual interactions. Social isolation and social exclusion resulted from the avoidance of stereotypic interactions and were often a consequence of difficulties with concealment of sexual needs due to stigma. Women discussed a range of negative experiences arising in response to their sexual needs in postdivorce life. The analysis revealed the complexities of gendered postdivorce sexual trajectories. Based on the findings, articulating a sexual health model specific for divorced women seems important.     

The Role of Metacognition in the Development of EFL Learners’ Listening Skill

This study investigated the impact of metacognitive instruction on the listening skill, and metacognitive knowledge of a group of male students (N = 30) who were learning English as a Foreign Language (EFL) in Iran. The study participants spoke Persian as a first language and were high-intermediate EFL learners. The participants received a guided lesson plan in metacognition (planning, monitoring, and evaluation) through a pedagogical cycle approach over a semester (eight weeks). International English Language Testing System listening tests (practice) were used to track the participants’ listening performance. Participants also completed a Metacognitive Awareness Listening Questionnaire, which examined their use of metacognitive awareness when engaged in listening tasks. Results indicated that the students improved their listening skill after being taught about metacognition; however, no significant use of metacognitive awareness was reported. This study concludes with a discussion of some potential implications, and provides scope for future research.     

A simplified algebraic method for system of linear inequalities with LP applications

In this pedagogical note we present an improved method to solve and analyze linear programming (LP) problems. The method depends on solving a system of equations and is free of any slack, surplus or artificial variables. The proposed method eliminates the need to manipulate linear inequalities to introduce additional variables and works only within the original decision variables space. We present applications of the method to handle linear optimization with varying objective function. The proposed method is easy to implement and enhances understanding of the simplex method and LP solvers transparent. We believe it is a useful alternative approach to present LP in the class room during the first few hours of introducing the subject.     

Optimal stabilization policies for housing activity

The usual approach in econometric modeling is to assume that the behavior of government agencies is exogenous. In this paper we have suggested that the policies of government agencies are not truly exogenous and should be studied in relation to the specific objectives pursued by these agencies.Within this framework, we investigated the implications of optimizing the behavior of two U.S. government agencies, Federal Home Loan Bank (FHLB) and Federal National Mortgage Association (FNMA), involved in the housing market. The technique we have utilized is dynamic programming.Based on the assumption that there agencies attempt to stabilize the housing market we have calculated the values for the optimal strategies in the past years and compared them with the historical patterns they have actually followed. Our interpretation of the behavior of these agencies is as follows: FHLB has a significant potential for housing stabilization. However, it has historically put more emphasis on keeping a uniform policy than stabilizing the housing activity. In this way, the role it has played in the housing market may be more destabilizing than stabilizing. On the other hand, FNMA's activity has had a rather uncertain effect on the housing stabilization. The conservative policies that FNMA has followed in the past are consistent with the uncertainties implicit in decision making but, at the same time, can be blamed for failing to create sufficient information regarding their effectiveness on the housing stabilization.     

Characterisation of forests with trivial game domination numbers

In the domination game, two players, the Dominator and Staller, take turns adding vertices of a fixed graph to a set, at each turn increasing the number of vertices dominated by the set, until the final set \(A_*\) dominates the whole graph. The Dominator plays to minimise the size of the set \(A_*\) while the Staller plays to maximise it. A graph is \(D\)-trivial if when the Dominator plays first and both players play optimally, the set \(A_*\) is a minimum dominating set of the graph. A graph is \(S\)-trivial if the same is true when the Staller plays first. We consider the problem of characterising \(D\)-trivial and \(S\)-trivial graphs. We give complete characterisations of \(D\)-trivial forests and of \(S\)-trivial forests. We also show that \(2\)-connected \(D\)-trivial graphs cannot have large girth, and conjecture that the same holds without the connectivity condition.