Perancangan Antena Mikrostrip Bentuk Segiempat Dual Frequency untuk Aplikasi WLAN 2400 Mhz dan 5000 Mhz

— Dalam penelitian ini dilakukan perancangan antena mikrostrip bentuk segiempat untuk frekuensi 2400 MHz dan 5000 MHz memenuhi standar WLAN IEEE 802.11b dan IEEE 802.11a. Antena ini memiliki impedansi masukan sebesar 50 Ω dengan ukuran patch segiempat W = 30 mm dan L = 29 mm menggunakan substrat FR4 (h = 1,6 mm). Lebar saluran pencatu adalah 3,1 mm dengan panjang 6 mm. Untuk menghasilkan dual frequency, dilakukan dengan menambahkan beban slit pada patch antena. Dari hasil simulasi diperoleh nilai return loss sebesar -13,06 dB untuk frekuensi 2400 MHz dan -31,64 dB untuk frekuensi 5000 MHz dengan nilai VSWR sebesar 1,575 untuk 2400 MHz dan 1,054 untuk 5000 MHz. Bandwidth pada frekuensi 2400 MHz dan 5000 MHz berturut-turut adalah 134 MHz (5,58%) dan 630 MHz (12,6%). Prototipe dari antena yang dirancang telah dipabrikasi, namun belum dilakukan pengujian. Rancangan yang sederhana namun mampu memenuhi tujuan yang diinginkan merupakan keunggulan dibandingkan penelitian sebelumnya. Kata kunci — Antena mikrostrip, segiempat, WLAN, dual frequency, beban sli

Thermal Radiation from Nucleons and Mesons

Thermal photon emission rates due to meson-nucleon interactions have been evaluated. An exhaustive set of reactions involving p(\bar p), n(\bar n), rho, omega, a_1, pi and eta is seen to provide a sizeable contribution to the emission rate from hot hadronic matter. Contributions from baryonic resonances are found to be negligibly small

Activity Recognition and Prediction in Real Homes

In this paper, we present work in progress on activity recognition and prediction in real homes using either binary sensor data or depth video data. We present our field trial and set-up for collecting and storing the data, our methods, and our current results. We compare the accuracy of predicting the next binary sensor event using probabilistic methods and Long Short-Term Memory (LSTM) networks, include the time information to improve prediction accuracy, as well as predict both the next sensor event and its mean time of occurrence using one LSTM model. We investigate transfer learning between apartments and show that it is possible to pre-train the model with data from other apartments and achieve good accuracy in a new apartment straight away. In addition, we present preliminary results from activity recognition using low-resolution depth video data from seven apartments, and classify four activities - no movement, standing up, sitting down, and TV interaction - by using a relatively simple processing method where we apply an Infinite Impulse Response (IIR) filter to extract movements from the frames prior to feeding them to a convolutional LSTM network for the classification.Comment: 12 pages, Symposium of the Norwegian AI Society NAIS 201

Uniform shear flow in dissipative gases. Computer simulations of inelastic hard spheres and (frictional) elastic hard spheres

In the preceding paper (cond-mat/0405252), we have conjectured that the main transport properties of a dilute gas of inelastic hard spheres (IHS) can be satisfactorily captured by an equivalent gas of elastic hard spheres (EHS), provided that the latter are under the action of an effective drag force and their collision rate is reduced by a factor $(1+\alpha)/2$ (where $\alpha$ is the constant coefficient of normal restitution). In this paper we test the above expectation in a paradigmatic nonequilibrium state, namely the simple or uniform shear flow, by performing Monte Carlo computer simulations of the Boltzmann equation for both classes of dissipative gases with a dissipation range $0.5\leq \alpha\leq 0.95$ and two values of the imposed shear rate $a$. The distortion of the steady-state velocity distribution from the local equilibrium state is measured by the shear stress, the normal stress differences, the cooling rate, the fourth and sixth cumulants, and the shape of the distribution itself. In particular, the simulation results seem to be consistent with an exponential overpopulation of the high-velocity tail. The EHS results are in general hardly distinguishable from the IHS ones if $\alpha\gtrsim 0.7$, so that the distinct signature of the IHS gas (higher anisotropy and overpopulation) only manifests itself at relatively high dissipationsComment: 23 pages; 18 figures; Figs. 2 and 9 include new simulations; two new figures added; few minor changes; accepted for publication in PR

Flavour equilibration in quark-gluon plasma

Within the framework of a dynamical and physically transparent model developed earlier, we study the time evolution of various quark flavours in the baryon-free region in ultrarelativistic heavy ion collisions. We show that even under optimistic conditions, the quark-gluon system fails to achieve chemical equilibrium

Cluster Production in Quark-Hadron Phase Transition

The problem of cluster formation and growth in first-order quark-hadron phase transition in heavy-ion collisions is considered. Behaving as Brownian particles, the clusters carry out random walks and can encounter one another, leading to coalescence and breakup. A simulation of the process in cellular automaton suggests the possibility of a scaling distribution in the cluster sizes. The experimental determination of the cluster-size distribution is urged as a means to find a clear signature of phase transition.Comment: 12 pages + 1 figure. Report # OITS-517. To be published in Phys. Rev. Lett. 71, xxx (1994