The Evolution of the Returns to Human Capital in Canada, 1980-2005

We examine the evolution of the returns to human capital in Canada over the period 1980-2005. Our main finding is that returns to education increased substantially for Canadian men, contrary to conclusions reached previously. Most of this rise took place in the early 1980s and since 1995. Returns to education also rose, albeit more modestly, for Canadian women. Another important development is that after years of expansion, the wage gap between younger and older workers stabilized after 1995. Controlling for work experience and using Canadian Census data appear to account for the main differences between our results and earlier findings.Human Capital, Wage Differentials, Canada

The Evolution of the Returns to Human Capital in Canada, 1980 - 2006

This paper examines the evolution of the returns to human capital in Canada over the period 1980-2006. Most of the analysis is based on Census data, and on weekly wage and salary earnings of full-time workers. Our main finding is that the returns to education increased substantially for Canadian men between 1980 and 2000, in contrast to conclusions reached in previous studies. For example, the adjusted wage gap between men with exactly a bachelors’ degree and men with only a high school diploma increased from 34 percent to 43 percent during this period. Most of this rise took place in the early 1980s and late 1990s. Returns to education also rose for Canadian women, but the magnitudes of the increases were more modest. For instance, the adjusted BA-high school wage differential among women increased about 4 percentage points between 1980 and 1985 and remained stable thereafter. Results based on Labour Force Survey data show the upward trend in returns to education has recently been reversed for both men and women. Another important development is that after fifteen years of expansion (1980-1995), the return to work experience measured by the wage gap between younger and older workers declined between 1995 and 2000. Finally, we find little difference between measures based on means and those based on medians of log wages for both genders. Also, the use of broader earnings measures (such as including self-employment earnings, using weekly earnings of all workers, or using annual earnings of full-time workers) does not alter the main conclusions from the analysis based on weekly wage and salary earnings of full-time workers.Human Capital, Wage Differentials, Returns to Education, Canada

Comparative Analysis Spread Spectrum and Parity Coding Steganography in E-commerce

The transaction data online has increased compared to the previous communications that mostly in the form of voice and text messaging. To improve the security, data must be protected such a way that it cannot be attacked by unauthorized parties. In this case, a good security system must be able to transmit the original information to the second party without having to know the existence and validity by a third party. One of the security systems that can be used is steganography. In this paper, we will compare the performance of Spread Spectrum and Parity Coding in e-commerce based on Android in case of processing time between insertion and retrieval information, and the changing image size during the insertion process. Our experimental results show that parity coding has better performance on client side that use low performance smart phone based on Android operating system and spread spectrum has better performance on blackberry store server that use laptop PC

Homogenization of the one-dimensional wave equation

We present a method for two-scale model derivation of the periodic homogenization of the one-dimensional wave equation in a bounded domain. It allows for analyzing the oscillations occurring on both microscopic and macroscopic scales. The novelty reported here is on the asymptotic behavior of high frequency waves and especially on the boundary conditions of the homogenized equation. Numerical simulations are reported

Analisa PSNR Pada Teknik Steganografi Menggunakan Spread Spectrum

Penelitian ini bertujuan untuk menganalisa pengaruh derau (noise) pada gambar yang terstego pada proses steganografi. Algoritma yang digunakan adalah spread spectrum dan parity coding, algoritma ini akan diterapkan pada proses steganografi untuk aplikasi ecommerce. Pesan rahasia yang distegokan meliputi nomor dan password kartu kredit. Data terstego berupa berkas gambar baru yang telah tersisipi data penting tersebut yang kemudian dikirim kembali ke server untuk proses pengembalian. Hasil akhir yang diperoleh dari penelitian ini adalah analisa ketahanan gambar jika terkena derau (noise) pada proses steganografi.Pengujian PSNR dilakukan 2 tahap, tahap pertama pada proses pembentukan gambar stego dari gambar asli, dimana kedua metode memberikan PSNR diatas 50 dB. Tahap kedua yaitu disimulasikan pada proses pengiriman gambar stego terdapat serangan MITM (man in the middle attack) dengan memberikan titik-titik hitam pada gambar, maka hasil PSNR langsung turun dibawah 30 dB. Pada pemberian titik hitam ini dilakukan pengujian sebanyak 10 titik hitam, pada metode parity coding, tidak bisa mengembalikan data yang disisipkan sedangkan pada metode spread spectrum masih bis

Effect of the measurement on the decay rate of a quantum system

We investigated the electron tunneling out of a quantum dot in the presence of a continuous monitoring by a detector. It is shown that the Schr\"odinger equation for the whole system can be reduced to new Bloch-type rate equations describing the time-development of the detector and the measured system at once. Using these equations we find that the continuous measurement of the unstable system does not affect its exponential decay, $\exp (-\Gamma t)$, contrary to expectations based on the Quantum Zeno effect . However, the width of the energy distribution of the tunneling electron is no more $\Gamma$, but increases due to the decoherence, generated by the detector.Comment: Additional explanations are added. Accepted for publications in Phys. Rev. Let

Le carcinome indifférencié des glandes salivaires

Le carcinome indifferencie primitif des glandes salivaires est rare. Son association avec le virus Epstein Barr, initialement decrite chez les esquimaux, est retrouvee dans la majorite des cas publies. Nous rapportons un nouveau cas tunisien survenu chez un homme age de 64 ans, revele par une tumefaction de la glande parotide gauche. Microscopiquement se discutait le caractere primitif ou secondaire de la tumeur, etaye par les examens complementaires. Le patient etait traite par une parotidectomie suivie d’un curage ganglionnaire et d’une radiotherapie. L’evolution etait favorable apres un an de recul.  Mots clès : Glande salivaire- Carcinome indifferencie- Virus Epstein Bar

Influence of measurement on the life-time and the line-width of unstable systems

We investigate the quantum Zeno effect in the case of electron tunneling out of a quantum dot in the presence of continuous monitoring by a detector. It is shown that the Schr\"odinger equation for the whole system can be reduced to Bloch-type rate equations describing the combined time-development of the detector and the measured system. Using these equations we find that continuous measurement of the unstable system does not affect its exponential decay to a reservoir with a constant density of states. The width of the energy distribution of the tunneling electron, however, is not equal to the inverse life-time -- it increases due to the decoherence generated by the detector. We extend the analysis to the case of a reservoir described by an energy dependent density of states, and we show that continuous measurement of such quantum systems affects both the exponential decay rate and the energy distribution. The decay does not always slow down, but might be accelerated. The energy distribution of the tunneling electron may reveal the lines invisible before the measurement.Comment: 13 pages, 8 figures, comments and references added; to appear in Phys. Rev.

Homogenized dynamics of stochastic partial differential equations with dynamical boundary conditions

A microscopic heterogeneous system under random influence is considered. The randomness enters the system at physical boundary of small scale obstacles as well as at the interior of the physical medium. This system is modeled by a stochastic partial differential equation defined on a domain perforated with small holes (obstacles or heterogeneities), together with random dynamical boundary conditions on the boundaries of these small holes. A homogenized macroscopic model for this microscopic heterogeneous stochastic system is derived. This homogenized effective model is a new stochastic partial differential equation defined on a unified domain without small holes, with static boundary condition only. In fact, the random dynamical boundary conditions are homogenized out, but the impact of random forces on the small holes' boundaries is quantified as an extra stochastic term in the homogenized stochastic partial differential equation. Moreover, the validity of the homogenized model is justified by showing that the solutions of the microscopic model converge to those of the effective macroscopic model in probability distribution, as the size of small holes diminishes to zero.Comment: Communications in Mathematical Physics, to appear, 200