Broken electroweak phase at high temperature in the Littlest Higgs model with T-parity

We have examined in detail the nonrestoration of symmetry at high temperature in a finite-temperature Littlest Higgs model, without and with T-parity, by evaluating the one-loop-order finite-temperature integrals of the effective potential numerically, without the high-temperature approximation, We observe that in the model without T-parity it is not possible to find a transition temperature within the allowed temperature range of the model (0<T<4f) if the UV completion factors are those which give the Standard Model electroweak minimum, as the effective potential always increases with temperature in the positive direction. However, in the case of the model with T-parity, it is possible to find a transition temperature with the same set of UV completion factors, as, with the increase of temperature, the effective potential decreases in magnitude in the positive side, becomes negative, and increases in magnitude in the negative side, indicating symmetry breaking at high temperature. This type of symmetry nonrestoration at high temperature has been observed earlier in some models involving pseudo Nambu-Goldstone bosons. The behaviour of the global structure of the effective potential with T-parity in the theory indicates a strong first order electroweak phase transition, conducive to baryogenesis in the early universe.Comment: 25 pages, 9 colour figures, references updated, explanation adde

Stable Marriage with Multi-Modal Preferences

We introduce a generalized version of the famous Stable Marriage problem, now based on multi-modal preference lists. The central twist herein is to allow each agent to rank its potentially matching counterparts based on more than one "evaluation mode" (e.g., more than one criterion); thus, each agent is equipped with multiple preference lists, each ranking the counterparts in a possibly different way. We introduce and study three natural concepts of stability, investigate their mutual relations and focus on computational complexity aspects with respect to computing stable matchings in these new scenarios. Mostly encountering computational hardness (NP-hardness), we can also spot few islands of tractability and make a surprising connection to the \textsc{Graph Isomorphism} problem

Analytical and finite-element study of optimal strain distribution in various beam shapes for energy harvesting applications

Due to the increasing demand for harvesting energy from environmental vibration, for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted great interest from various parties and become one of the most common approaches to convert redundant mechanical energy into electrical energy. As the output voltage produces from a piezoelectric material depends greatly on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing geometries. This paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beams that have been overseen in most of the prior literature. Both analytical and finite element models are derived and the resultant strain distributions in the beam are computed based on MATLAB solver and ANSYS finite element analysis tools. An optimum geometry for a vibration-based energy harvester system is verified. Lastly, experimental results comparing the power density for a triangular and rectangular piezoelectric beams are also presented to validate the finding of the study and the claim as suggested in the literature is verified

On Physical Properties of Cylindrically Symmetric Self-Similar Solutions

This paper is devoted to discuss some of the features of self-similar solutions of the first kind. We consider the cylindrically symmetric solutions with different homotheties. We are interested in evaluating the quantities acceleration, rotation, expansion, shear, shear invariant and expansion rate. These kinematical quantities are discussed both in co-moving as well as in non-co-moving coordinates (only in radial direction). Finally, we would discuss the singularity feature of these solutions. It is expected that these properties would help in exploring some interesting features of the self-similar solutions.Comment: 16 pages, accepted for publication in Int. J. of Mod. Phys.

Kinematic Self-Similar Cylindrically Symmetric Solutions

This paper is devoted to find out cylindrically symmetric kinematic self-similar perfect fluid and dust solutions. We study the cylindrically symmetric solutions which admit kinematic self-similar vectors of second, zeroth and infinite kinds, not only for the tilted fluid case but also for the parallel and orthogonal cases. It is found that the parallel case gives contradiction both in perfect fluid and dust cases. The orthogonal perfect fluid case yields a vacuum solution while the orthogonal dust case gives contradiction. It is worth mentioning that the tilted case provides solution both for the perfect as well as dust cases.Comment: 22 pages, accepted for publication in Int. J. of Mod. Phys.

Pengaruh Metode Pembelajaran Peta Pikiran Terhadap Hasil Belajar Siswa Pada Materi Pokok Getaran Dan Gelombang Di Kelas VIII SMP Negeri 12 Binjai

Penelitian ini bertujuan untuk mengetahui pengaruh metodepembelajaran peta pikiran terhadap hasil belajar siswa pada materi pokok getaran dan gelombang di kelas VIII semester II SMP Negeri 12 Binjai T.A 2009/2010. Jenis penelitian ini adalah eksperimen two group pretest postest design. Dari hasil perhitungan diperoleh nilai rata-rata pretes kelas eksperimen adalah 39,89 dan kelas kontrol 36,66. Setelah dilakukan perlakuan pada masing-masing kelas diperoleh nilai rata-rata nilai postes pada kelas dengan pembelajaran metode peta pikiran sebesar 80,33 sedangkan siswa dengan pembelajaran konvensional diperoleh nilai rata-rata 64,66. Hasil pengamatan aktivitas siswa selama proses pembelajaran pada kelas dengan metode peta pikiran diperoleh rata-rata 77,5 dengan kategori nilai cukup aktif. Hasil uji-t diperoleh thitung = 6,74 dan ttabel = 1,66 pada taraf nyata a = 0,05 dan dk = 70 dimana thitung > ttabel, ini berarti ada pengaruh yang signifikan penerapan metode pembelajaran peta pikiran terhadap hasil belajar siswa pada materi pokok getaran dan gelombang di kelas VIII semester II SMP Negeri 12 Binjai T.A 2009/2010

Integrating vocational training in culinary arts and Islamic studies at juvenile rehabilitation centres: Malaysian experience

The Juvenile Rehabilitation Centres (JRC) in Malaysia aims to provide shelter, counselling and skills training to juveniles specifically for those who wish to transform themselves from the regrettable misdeeds they have committed. At JRCs, an integrated Culinary Vocational Training and Islamic education forms part of their training curriculum. The skills acquired should enable trainees to secure jobs upon completion of training. However, there are some training institutions that lack systematic training structures resulting in trainees becoming less skilful in both vocational and Islamic education. The objective of this research is to identify the effectiveness of an integrated Culinary and Islamic Education curriculum implemented at JRCs in Malaysia. This is a descriptive survey and data was obtained using questionnaire and interview. Respondents comprised 92 trainees, four managers, four culinary trainers and four Islamic education teachers, all from four different JRCs. The findings show that the trainees are happy with their trainings that brought about positive effects for them. Some suggestions have been made to provide improvements in the implementation of the course among them the inclusion of prayers in the Islamic education syllabus

Weakly coupled two slow- two fast systems, folded node and mixed mode oscillationsM

We study Mixed Mode Oscillations (MMOs) in systems of two weakly coupled slow/fast oscillators. We focus on the existence and properties of a folded singularity called FSN II that allows the emergence of MMOs in the presence of a suitable global return mechanism. As FSN II corresponds to a transcritical bifurcation for a desingularized reduced system, we prove that, under certain non-degeneracy conditions, such a transcritical bifurcation exists. We then apply this result to the case of two coupled systems of FitzHugh- Nagumo type. This leads to a non trivial condition on the coupling that enables the existence of MMOs