40 research outputs found
Coping Strategies for Youth Suffering from Online Interpersonal Rejection
The Internet and social media have rapidly changed our lives, and are profoundly affecting the social lives of adolescents, expanding and enriching their communication options. At the same time, they often operate as a platform that amplifies the real-world phenomenon of interpersonal rejection â a harsh and excruciating experience. In this study, we will examine, youth\u27s coping methods with online social rejection from a psycho-social perspective. To achieve this objective, a data-based heuristic model was developed, based on in-depth interviews with 19 adolescents from Israel who experienced online rejection. The findings show several coping strategies ranging from adaptive to maladaptive online and offline used interchangeably
Recommended from our members
Symmetric Public-Key Encryption
Public-key encryption would seem to be inherently asymmetric. in that only messages sent to a user can be encrypted using his public key. We demonstrate that the use of interactive protocols for sending encrypted messages enables a symmetric use of public keys; we give cryptographic protocols for the following tasks: 1. Probabilistic encryption, using the same public key, both of messages that are sent to a particular user as well as of messages that the user sends to others, without compromising the key. We propose a public-key cryptosystem based on these protocols which has only one key, owned by a cryptographic server. 2. Authentication both of the sender and of the receiver of a probabilistically encrypted message. 3. Probabilistic encryption which is provably secure against both chosen-message and chosen-ciphertext attack
Recommended from our members
Distributed Algorithms in Synchronous Broadcasting Networks
In this paper we consider a synchronous broadcasting network, a distributed computation model which represents communication networks that are used extensively in practice. This is the first work we know of that deals with this model in a theoretical context. The problem we consider is a basic problem of information sharing, the computation of the multiple identification function. That is, given a network of p processors, each of which contains an n-bit string of information, the question is how every processor can compute the subset of processors which have the same information as itself. The problem was suggested by Yao in his classical paper in communication complexity [17], as a generalization of the two-processor case studied in that paper. The immediate algorithm which solves this problem takes O(np) time (time = communication time in bits, which is our complexity measure). We present the following algorithms: - a. An algorithm which takes advantage of properties of strings, uses a very simple scheduling policy, and does not use arithmetic operations. (In fact, the processor can be a Turing machine). 'the algorithm's complexity is O(nlog2p+p). - b. An algorithm which uses a simulation of sorting networks by the distributed system. If t(p) is the depth of the sorting network of p processors, then our algorithm takes O( n t(p) + p) time. Using recent results on sorting networks we get an O(nlogp+p) (impractical) algorithm. The algorithm also uses addition and subtraction operations. -c. By letting the processor use modular arithmetic operations as well, we can use Yao's probabilistic version, modify our algorithms and get probabilistic algorithms (with small error) where logn replaces n in the complexity expressions. To prove lower bounds for the problem we use Yao's result to get an fl(n) bound, and we also show an fl(p) bound. We suggest open problems concerning new techniques for proving lower bounds in the presence of broadcasting, as well as other problems about efficient use of the model and comparisons between different models of distributed computation
Recommended from our members
Distributed Algorithms in Synchronous Broadcasting Networks
In this paper we consider a synchronous broadcasting network, a distributed computation model which represents communication networks that are used extensively in practice. This is the first work we know of that deals with this model in a theoretical context. The problem we consider is a basic problem of information sharing, the computation of the multiple identification function. That is, given a network of p processors, each of which contains an n-bit string of information, the question is how every processor can compute the subset of processors which have the same information as itself. The problem was suggested by Yao in his classical paper in communication complexity [17], as a generalization of the two-processor case studied in that paper. The immediate algorithm which solves this problem takes O(np) time (time = communication time in bits, which is our complexity measure). We present the following algorithms: - a. An algorithm which takes advantage of properties of strings, uses a very simple scheduling policy, and does not use arithmetic operations. (In fact, the processor can be a Turing machine). 'the algorithm's complexity is O(nlog2p+p). - b. An algorithm which uses a simulation of sorting networks by the distributed system. If t(p) is the depth of the sorting network of p processors, then our algorithm takes O( n t(p) + p) time. Using recent results on sorting networks we get an O(nlogp+p) (impractical) algorithm. The algorithm also uses addition and subtraction operations. -c. By letting the processor use modular arithmetic operations as well, we can use Yao's probabilistic version, modify our algorithms and get probabilistic algorithms (with small error) where logn replaces n in the complexity expressions. To prove lower bounds for the problem we use Yao's result to get an fl(n) bound, and we also show an fl(p) bound. We suggest open problems concerning new techniques for proving lower bounds in the presence of broadcasting, as well as other problems about efficient use of the model and comparisons between different models of distributed computation
Microstructural Evolution of Cr-Rich ODS Steels as a Function of Heat Treatment at 475°C
In the current research, the effect of heat treatment on the morphology of the dispersoids and their phase composition were investigated in three Cr-rich ferritic oxide dispersion strengthened (ODS) steels: PM2000, MA956, and ODM751. The steels were aged at 475°C for
times ranging from 100 to 1,000 h. The microstructure was characterized using transmission electron microscopy. Study of the as-recrystallized samples revealed nano-scale YâAlâO complex-oxide particles dispersed in the ferritic matrix. These dispersoids, which differ in size (10â160 nm) and geometry (polygonal and spherical), were identified as Y4Al2O9, YAlO3, and Y3Al5O12. After heat treatment, a
significant change in the morphology, size, and distribution of the dispersoids was observed. Changes in the phase composition of the oxide dispersoids were also observed: YAlO3 (with perovskite structure) was identified as the most dominant phase, indicating that it is probably the most stable phase in the Cr-rich ferritic ODS steels.JRC.F.4-Nuclear Reactor Integrity Assessment and Knowledge Managemen
One-Loop Corrections to Two-Quark Three-Gluon Amplitudes
We present the one-loop QCD amplitudes for two external massless quarks and
three external gluons (). This completes the set of one-loop
amplitudes needed for the next-to-leading-order corrections to three-jet
production at hadron colliders. We also discuss how to use group theory and
supersymmetry to minimize the amount of calculation required for the more
general case of one-loop two-quark -gluon amplitudes. We use collinear
limits to provide a stringent check on the amplitudes.Comment: plain Tex, 46 pages with 13 figures in a uuencoded file, corrected
case j=1 of eq. (IV.7), and signs in eq. (4.9
Two-Loop g -> gg Splitting Amplitudes in QCD
Splitting amplitudes are universal functions governing the collinear behavior
of scattering amplitudes for massless particles. We compute the two-loop g ->
gg splitting amplitudes in QCD, N=1, and N=4 super-Yang-Mills theories, which
describe the limits of two-loop n-point amplitudes where two gluon momenta
become parallel. They also represent an ingredient in a direct x-space
computation of DGLAP evolution kernels at next-to-next-to-leading order. To
obtain the splitting amplitudes, we use the unitarity sewing method. In
contrast to the usual light-cone gauge treatment, our calculation does not rely
on the principal-value or Mandelstam-Leibbrandt prescriptions, even though the
loop integrals contain some of the denominators typically encountered in
light-cone gauge. We reduce the integrals to a set of 13 master integrals using
integration-by-parts and Lorentz invariance identities. The master integrals
are computed with the aid of differential equations in the splitting momentum
fraction z. The epsilon-poles of the splitting amplitudes are consistent with a
formula due to Catani for the infrared singularities of two-loop scattering
amplitudes. This consistency essentially provides an inductive proof of
Catani's formula, as well as an ansatz for previously-unknown 1/epsilon pole
terms having non-trivial color structure. Finite terms in the splitting
amplitudes determine the collinear behavior of finite remainders in this
formula.Comment: 100 pages, 33 figures. Added remarks about leading-transcendentality
argument of hep-th/0404092, and additional explanation of cut-reconstruction
uniquenes
One-Loop n-Point Gauge Theory Amplitudes, Unitarity and Collinear Limits
We present a technique which utilizes unitarity and collinear limits to
construct ansatze for one-loop amplitudes in gauge theory. As an example, we
obtain the one-loop contribution to amplitudes for gluon scattering in
supersymmetric Yang-Mills theory with the helicity configuration of the
Parke-Taylor tree amplitudes. We prove that our ansatz is correct using
general properties of the relevant one-loop -point integrals. We also give
the ``splitting amplitudes'' which govern the collinear behavior of one-loop
helicity amplitudes in gauge theories.Comment: 52 pages (including figures), minor typographical errors corrected,
SLAC-PUB-641
One-Loop Amplitudes for e^+ e^- to Four Partons
We present the first explicit formulae for the complete set of one-loop
helicity amplitudes necessary for computing next-to-leading order corrections
for e^+ e^- annihilation into four jets, for W, Z or Drell-Yan production in
association with two jets at hadron colliders, and for three-jet production in
deeply inelastic scattering experiments. We include a simpler form of the
previously published amplitudes for e^+ e^- to four quarks. We obtain the
amplitudes using their analytic properties to constrain their form.
Systematically eliminating spurious poles from the amplitudes leads to
relatively compact results.Comment: Tex, 82 pages, Maple and Mathematica files containing the amplitudes
are available from the author
Listeria monocytogenes Infection in Israel and Review of Cases Worldwide
Listeria monocytogenes, an uncommon foodborne pathogen, is increasingly recognized as a cause of life-threatening disease. A marked increase in reported cases of listeriosis during 1998 motivated a retrospective nationwide survey of the infection in Israel. From 1995 to 1999, 161 cases were identified; 70 (43%) were perinatal infections, with a fetal mortality rate of 45%. Most (74%) of the 91 nonperinatal infections involved immunocompromised patients with malignancies, chronic liver disease, chronic renal failure, or diabetes mellitus. The common clinical syndromes in these patients were primary bacteremia (47%) and meningitis (28%). The crude case-fatality rate in this group was 38%, with a higher death rate in immunocompromised patients