Probability density functions in turbulent channel flow

The probability density functions (pdf's) of the fluctuating velocity components, as well as their first and second derivatives, are calculated using data from the direct numerical simulations (DNS) of fully developed turbulent channel flow. It is observed that, beyond the buffer region, the pdf of each of these quantities is independent of the distance from the channel wall. It is further observed that, beyond the buffer region, the pdf's for all the first derivatives collapse onto a single universal curve and those of the second derivatives also collapse onto another universal curve, irrespective of the distance from the wall. The kinetic-energy dissipation rate exhibits log normal behavior

Fast generation of stability charts for time-delay systems using continuation of characteristic roots

Many dynamic processes involve time delays, thus their dynamics are governed by delay differential equations (DDEs). Studying the stability of dynamic systems is critical, but analyzing the stability of time-delay systems is challenging because DDEs are infinite-dimensional. We propose a new approach to quickly generate stability charts for DDEs using continuation of characteristic roots (CCR). In our CCR method, the roots of the characteristic equation of a DDE are written as implicit functions of the parameters of interest, and the continuation equations are derived in the form of ordinary differential equations (ODEs). Numerical continuation is then employed to determine the characteristic roots at all points in a parametric space; the stability of the original DDE can then be easily determined. A key advantage of the proposed method is that a system of linearly independent ODEs is solved rather than the typical strategy of solving a large eigenvalue problem at each grid point in the domain. Thus, the CCR method significantly reduces the computational effort required to determine the stability of DDEs. As we demonstrate with several examples, the CCR method generates highly accurate stability charts, and does so up to 10 times faster than the Galerkin approximation method.Comment: 12 pages, 6 figure

Model Program Pendidikan Guru Prajabatan: Dari Penghapusan Akta IV Menuju Sertifikat Profesi

Tidak ada penyelenggaraan program pendidikan profesi guru prajabatan yang secara mapan dan masif pasca penghapusan Akta IV. Guru prajabatan yang lulus dari jenjang sarjana tidak lagi memegang Akta IV ketika di sisi lain kesempatan mengikuti pendidikan profesi guru pun belum ada. Terdapat kekosongan program dan lisensi mengajar bagi guru prajabatan. Maka bermunculan model-model program pendidikan guru prajabatan yang berperan memperkuat kompetensi guru pada masa pasca penghapusan Akta IV dan belum terselenggarakannya pendidikan profesi guru. Beberapa alternatif model program pendidikan guru prajabatan pada jenjang S1 adalah sebagai berikut. Model pertama, program mayor ganda sarjana pendidikan ditambah ilmu murni. Model kedua, program mayor ganda sarjana ilmu murni ditambah sarjana pendidikan. Model ketiga, program mayor dan gelar ganda sarjana pendidikan dari minimal dua perguruan tinggi berbeda. Model keempat, program Sarjana Pendidikan mayor-minor

Aspek Pengembangan Karier Guru Sebagai Wakil/pembantu Kepala Sekolah (Assistant Principal)

Assistant principal is often known by various names such as vice-principals, assistant principal, experts consultant. Teachers who given additional duties to assistant principal, is must be competent and able to carry out duties other than teaching. It also develops the educational administration ability in school. An assistant principal position is prior to the period between the experienced teacher who is develops his career into principal and supervisor. The role of assistant principal is very important and it should be received serious attention to improve the effectiveness and efficiency of school management

Kepemimpinan Perempuan Bernilai Kesundaan Di Bidang Pendidikan

Indonesia facing the globalization of education which is widespread. Educational leadership is critical to direct the nation's educational goals will be taken. What kind of values which are the fad will greatly determine what kind of human being will be fostered. Sundanese indigenous value as the benefits of local culture to be one that strengthens the foundations of national culture in the face of onslaught of foreign culture. Leadership education is not only the role of men but also women. Sundanese women's leadership in education have specific values that are relevant to be applied as an effort to support national education vision of global-minded but still upholds the excellence local culture. Life philosophy of Sundanese people who have been recognized to have profound meaning is cageur (healthy), bageur (kind), bener (right), pinter (clever), singer (innovative) who also used in running leadership. Next Sunda educational value derived from the typical female is moher. Moheris a cute picture of a woman or a good and beautiful. Characteristic of these women then interpreted broadly to something beautiful, pleasant and soothing various parties as a result of the creativity of each person according to their personal characteristics that became his personal responsibilit