4,613 research outputs found
Qualitative telephone interviews: Strategies for success
The use of the telephone in qualitative interviews is discouraged by traditionalists who view it as an inferior data collection instrument. However these claims have not been supported by empirical evidence and qualitative researchers who have used and compared the telephone to the face-to-face mode of interviewing present a different story. This study attempts to build on the limited existing research comparing the issues involved and the data collected using the telephone and face-to-face interview modes. The study evaluates the criticisms of traditionalists in the light of existing research. The study then presents the observations of the researcher based on a research project that involved 43 telephone, 1 Skype and 6 face-to-face interviews. These observations as well as the limited prior research are used to develop strategies for the effective use telephone interviews in qualitative research. The study concludes that for certain studies the telephone if used with the strategies recommended here provides qualitative researchers with a sound data collection instrument
Higgs properties measurements using the four lepton decay channel
The measurements of the properties of the Higgs boson are presented in the
HZZ4 (=e,) decay channel using a
data sample corresponding to an integrated luminosity of 35.9 fb of
proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the
CMS detector at the LHC. The signal-strength modifier , defined as the
production cross section of the Higgs boson times its branching fraction to
four leptons relative to the standard model expectation, is measured to be
at . Constraints
are set on the strength modifiers for the main Higgs boson production modes.
The mass is measured to be and
the width is constrained using on-shell production to be
, at CL. The fiducial cross
section is measured to be , which is compatible with
the standard model prediction of .Comment: Presented at LHCP201
An Authentication Protocol for Future Sensor Networks
Authentication is one of the essential security services in Wireless Sensor
Networks (WSNs) for ensuring secure data sessions. Sensor node authentication
ensures the confidentiality and validity of data collected by the sensor node,
whereas user authentication guarantees that only legitimate users can access
the sensor data. In a mobile WSN, sensor and user nodes move across the network
and exchange data with multiple nodes, thus experiencing the authentication
process multiple times. The integration of WSNs with Internet of Things (IoT)
brings forth a new kind of WSN architecture along with stricter security
requirements; for instance, a sensor node or a user node may need to establish
multiple concurrent secure data sessions. With concurrent data sessions, the
frequency of the re-authentication process increases in proportion to the
number of concurrent connections, which makes the security issue even more
challenging. The currently available authentication protocols were designed for
the autonomous WSN and do not account for the above requirements. In this
paper, we present a novel, lightweight and efficient key exchange and
authentication protocol suite called the Secure Mobile Sensor Network (SMSN)
Authentication Protocol. In the SMSN a mobile node goes through an initial
authentication procedure and receives a re-authentication ticket from the base
station. Later a mobile node can use this re-authentication ticket when
establishing multiple data exchange sessions and/or when moving across the
network. This scheme reduces the communication and computational complexity of
the authentication process. We proved the strength of our protocol with
rigorous security analysis and simulated the SMSN and previously proposed
schemes in an automated protocol verifier tool. Finally, we compared the
computational complexity and communication cost against well-known
authentication protocols.Comment: This article is accepted for the publication in "Sensors" journal. 29
pages, 15 figure
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