Modeling and Maximum Likelihood Fitting of Gamma-Ray and Radio Light Curves of Millisecond Pulsars Detected with Fermi

Pulsed gamma rays have been detected with the Fermi Large Area Telescope (LAT) from more than 20 millisecond pulsars (MSPs), some of which were discovered in radio observations of bright, unassociated LAT sources. We have fit the radio and gamma-ray light curves of 19 LAT-detected MSPs in the context of geometric, outer-magnetospheric emission models assuming the retarded vacuum dipole magnetic field using a Markov chain Monte Carlo maximum likelihood technique. We find that, in many cases, the models are able to reproduce the observed light curves well and provide constraints on the viewing geometries that are in agreement with those from radio polarization measurements. Additionally, for some MSPs we constrain the altitudes of both the gamma-ray and radio emission regions. The best-fit magnetic inclination angles are found to cover a broader range than those of non-recycled gamma-ray pulsars.Comment: 4 pages, 3 figures, 2011 Fermi Symposium proceedings - eConf C110509 -- v2 corrects caption of Figure 1, v3 corrects missing fil

An observational study of mother-child interaction.

Thesis (M.S.)--Boston Universit

Timed Fault Tree Models of the China Yongwen Railway Accident

Safety is an essential requirement for railway transportation. There are many methods that have been developed to predict, prevent and mitigate accidents in this context. All of these methods have their own purpose and limitations. This paper presents a new useful analysis technique: timed fault tree analysis. This method extends traditional fault tree analysis with temporal events and fault characteristics. Timed Fault Trees (TFTs) can determine which faults need to be eliminated urgently, and it can also provide a safe time window to repair them. They can also be used to determine the time taken for railway maintenance requirements, and thereby improve maintenance efficiency, and reduce risks. In this paper, we present the features and functionality of a railway transportation system based on timed fault tree models. We demonstrate the applicability of our framework via a case study of the China Yongwen line railway accident

The Technology Acceptance Model and the Decision to Invest in Information Security

Security breaches have increasingly become a major threat to organizations. Nevertheless, according to recent reports, many organizations do not plan to increase spending on information security. In fact, little is known about an organization’s motivation to invest in information security. This paper uses the Technology Acceptance Model as a basis for studying factors that might motivate organizations to invest (or not to invest) in information security. It proposes that perceived usefulness and ease of use of information security influence such investment decisions. It further proposes that seven other variables influence perceived usefulness and ease of use. They are: external environment, prior information security experiences, perceived risks of not securing information, information security budget, security planning, confidence in information security, and security awareness and training. The research proposes a model of information security investment. A Delphi study and a mail survey will be used to test it

Review of \u3cem\u3eOpen Moral Communities.\u3c/em\u3e Seymore J. Mandelbaum. Reviewed by Alice K. Johnson

Book review of Seymour J. Mandelbaum. Open Moral Communities. Cambridge, MA: MIT Press, 2000. $30.00 hardcover

To Waive or Not to Waive? Filing Deadlines and Hearing Requests in Administrative Adjudications

In Part II of this Article, I provide an overview of subject matter jurisdiction in relation to filing timeframes. I review the distinction between original and appellate jurisdiction using Maryland case law and a sample survey of other state case law to provide background to the question of filing deadlines and hearing requests in administrative adjudications. In Part III of this Article, I elaborate upon Supreme Court precedent on administrative filing deadlines. In Part IV of this Article, I analyze the nature of filing deadlines for hearing requests before various state agencies, with an emphasis on Maryland’s scheme. The case law among the states is limited and contradictory, which raises the question in Part V of how to proceed with an untimely filing. What emerges from my review of time limitations in state and Supreme Court cases is that whether a jurisdictional bar exists is often a question of legislative intent. Because of the harshness of jurisdictional deadlines, I recommend that the relevant agency statute and regulations be carefully parsed to determine if there is any flexibility in the filing deadline

The effectiveness of contextualization on second language acquisition using the situational discourse semantic model

In traditional classrooms a second language is taught via thematic word sets, grammatical explanations, and patterned syntactic practice. This study compared the traditional teaching approach to a scaffolded teaching approach, consisting of words taught within a narrative context. Five fifth-grade students were taught Spanish as a second language during a ten-week intervention. Vocabulary learning and sentence generation were measured following each session, as well as a pre-posttest measure. Results showed that print was an important support used by participants in the traditional condition. However across time, vocabulary learning and sentence length increased significantly more in the scaffolded condition

A survey of nursery school children's interest in creative activities

Thesis (M.A.)--Boston University, 1948. This item was digitized by the Internet Archive

The Strategic Value of Information Security Research Participation

Although information security is an important issue, the ability to obtain subjects to participate in information security research is a challenge. The proposed research will study the link between the perceived strategic value of participating in information security research and the decision to participate. First, a perception of strategic value (PSV) instrument will be used to guide structured interviews to identify the value-drivers for such participation. Second, drawing on previous research and interview results, an instrument will be developed to assess the strategic value of participating in information security research. That instrument will then be used to answer research questions about the link between the perceived strategic value of participating in information security research and the decision to participate. The results of the study would help practitioners to understand the value of participating in information security research, thus resulting in more such studies and discoveries to enhance information security