549 research outputs found
Comment on: New limit on lorentz-invariance- and CPT-violating neutron spin interactions using a free-spin-precession 3He- 129Xe comagnetometer
pre-printIn Ref. [1], the authors use a classical result for the magnetic field created by a uniform magnetization to analyze the effects of magnetic interactions between 3He and 129Xe nuclear spins. We point out that the classical result is not applicable for interaction between nuclear spins: the actual interaction is much weaker. This calls into question the results of their analysis setting limits on Lorentz invariance. We also point out that the Letter does not contain any discussion of systematic errors in the determination of Lorentz-violation coefficients
Wetting and Growth Behaviors in Adsorbed Systems with Long-Range Forces
The growth and possible wetting behaviors of an adsorbed film are studied employing a solid-on-solid model in the presence of a hard wall and external potential V(h) which is of long range. The model is analyzed with the use of position-space renormalization-group methods within the Migdal approximation. The existence of wetting transitions and their nature depends on the asymptotic behavior of V(h) at large distances. We find that critical wetting cannot take place in this model. From what is known of V(h), we conclude that wetting can be observed only along the gas-liquid phase boundary; however, first-order transitions between thin and thick films, which may be experimentally difficult to distinguish from wetting, can be observed along any phase boundary. The nature of the global phase diagram depends on the form of V(h) and several general behaviors are presented. In particular, in the layering subregime we find that the limit of layering critical points is indeed the bulk roughening temperature as had been suggested by de Oliveira and Griffiths. The scaling of these layering critical points is given explicitly
Pengaruh Layanan Bimbingan Kelompok terhadap Peningkatan Leadership Ranting Ipm di Smk Muhammadiyah 2 Pekanbaru Periode 2014/2015
The tittle of this research is the effect of guidance group towards the increasing of leadership of IPM branch. Purpose of this research is: 1. To know the leadership of IPM branch before implementing the guidance group services. 2. To know the process of implementation of guidance group services in order to increase the leadership of IPM branch. 3. To know the leadership of IPM branch after implementing the guidance group services. 4. To know the difference between before and after implementing the guidance group services to the leadership of IPM branch. 5. To know is there any influence in the implementation of the guidance group services to increase the leadership of IPM branch. This research used the quasi experiment method, by using one group pretest-posttest design. The subject of this research was members of the IPM branch at SMK Muhammadiyah 2 Pekanbaru, about to 30 peoples, by using random sampling techniques. To know the level of students' leaders by using the questionnaires. Analysis of data using statistical techniques percentage, to distinguish the leadership of students' between before and after implementing guidance services group t-test was used obtained tgreater bigger than ttable (10.92> 2.0) to the significant level of 5%. So Ho rejected and Ha accepted which means that in this research there is a difference to the improvement of the leadership before and after implementing guidance group services. And then from the product moment coefficient r = 0.53 determinant that is r2 = 0.28. Based on the results of research, it can be concluded that there is a significant increase after the implementation of the guidance group services of the leadership of IPM branch at SMK Muhammadiyah 2 Pekanbaru 2014/2015 period
Analytical Investigation of Innovation Dynamics Considering Stochasticity in the Evaluation of Fitness
We investigate a selection-mutation model for the dynamics of technological
innovation,a special case of reaction-diffusion equations. Although mutations
are assumed to increase the variety of technologies, not their average success
("fitness"), they are an essential prerequisite for innovation. Together with a
selection of above-average technologies due to imitation behavior, they are the
"driving force" for the continuous increase in fitness. We will give analytical
solutions for the probability distribution of technologies for special cases
and in the limit of large times.
The selection dynamics is modelled by a "proportional imitation" of better
technologies. However, the assessment of a technology's fitness may be
imperfect and, therefore, vary stochastically. We will derive conditions, under
which wrong assessment of fitness can accelerate the innovation dynamics, as it
has been found in some surprising numerical investigations.Comment: For related work see http://www.helbing.or
Pengaruh Layanan Bimbingan Kelompok dengan Metode Games untuk Meningkatkan Motivasi Berprestasi Siswa Kelas X SMA Negeri 14 Pekanbaru Tp. 2015/2016
The success of students in learning process are really influenced by the achievement motivation. The low achievement motivationcan make students cannot reach the optimal learning result. In this case, schools, especially guidance teachers, are expected to have competences to do the action regarding the improvement of students' achievement motivation. The objective of this research is to know the influence group guidance services by using games method in improving students' achievement motivation on the experimental group. The method of this research is real-experimental method with the pattern of pre test-post test control group design. The subject of this research is 20 students of grade X SMA Negeri 14 Pekanbaru that have low achievement motivation. The technique of analyzing data applied three formula, Wilcoxon Experiment, Spearman Rank Experiment and Man Whitney Experiment. Based on the hypothesis experiment by applying SPSS 16.0, it is obtained that the value of sig. (2-tailed) is 0,117. Due to the fact that the value of sig. (2-tailed) more than the α value (0.117 > 0.05) thus it can be concluded that There is no positive impact that significant in giving group counseling services by using games method in improving students' achievement motivation. The influence of group guidance services by using games method in order to improve students' achievement motivation give contribution is 27,7%
Pengaruh Layanan Informasi Tentang Wawasan Karir terhadap Aspirasi Karir Siswa Kelas X Bb dan Dkv Smk Negeri 4pekanbaru T.p 2014/2015
Aspiration is the hope for the success of a person in realizing the desired career destination. But at the moment many students who could not think of a direction in planning your career. Hopes of success in achisving career is not yet offset by the knowledge the students for career insights, leaving students wrong in choosing majors. This research aims. 1) to know the description of the career aspirations of students prior knowledge given the information services about career insights. 2) to know the process of granting information services about career aspirations for career insights. 3) to know the description of the career aspirations of students after the knowledge given the information services about career insights. 4) to find out the level of knowledge of students ' career aspirations before with service after being given information about the career insights. 5) to know how big is the influence of information services about career aspirations for career insight students. Data collection tools in the form of scale career aspirations. The subject of research is the grade X BB and DKV SMKN 4 Pekanbaru that add up to 110 people. Determination of a sample using simple saturated. The sample in this study as many as 110 people. The description of the career aspirations of students before the given information services about career insights are in a high category of 54,45%, medium category of 38,18% very high category of 5.45%, and low of 1,82%,. The description of the career aspirations of students after being given information about the career insights are in a higher category of 50%, very high category of 46,37% and medium category of 3.63-%. Based on the hypothesis test results are then compared with big tcount and big ttable that is the result of the calculation with the "t" test, 5% error level = 1,968 then it can be seen that tcount is greater than ttable (10 > 1,968) on levels 5% error so it can be concluded that the hypothesis be accepted is there is a significant difference between the career aspirations of students before and after do information services about career insights
- …