This paper examines electromagnetic energy transmission through a narrow slot in a thick conducting plate when a plane wave is incident to the slot. The slot in the thick plate creates a waveguide structure. From the perspective of cutoff frequency, the transmission characteristics are classified into three modes. The transmission cavity resonance (TCR) mode in the range above the cutoff depends on the plate thickness, and peak transmission cross-sections (TCSs) appear periodically along the plate thickness, known as Fabry-Perot resonance. The near-cutoff resonance transmission (NCRT) mode depends on the slot length and plate thickness, and the maximum TCS appears only once as a slot length resonance (or transverse resonance). The peak TCS for the NCRT mode occurs with a thin plate thickness, which produces slot length resonance. The non-transmission cavity (NTC) mode is a non-transmission and non-resonance mode and is not propagated. All the maximum TCSs for the TCR and NCRT modes occur in parallel resonance. The analysis results show that the classification of the three transmission modes through the thick plate slot is effectively explained by the TCS and aperture impedance.
This paper presents the transmission cross-section (TCS) of a dual plate with narrow small slots when a plane wave is incident from the left half-space. Numerical results show that the TCS depends mainly on the plate spacing for a specified frequency. The TCS fluctuates with the plate spacing; the fluctuation period is approximately 0.5λ. When the plate spacing is larger than 0.5λ, the TCS reduces to 90% in the single plate case, and TCS enhancement is extremely difficult. However, when the plate spacing is less than 0.5λ, the TCS decreases gradually to approximately 36% in the single plate case, and TCS enhancement can be realized using two parallel wires. The analysis results show that resonance transmission is effectively obtained by the wires connected on the slots for a plate spacing within 0.5λ. Experimental measurements are presented to validate the theory.
The purpose of this study was to investigate the importance of recreation, park and cultural amenities relative to four other quality of life attributes in the location selection processes of four types of companies. the study solicited input from three sets of factors: company officials, economic development professionals and relocation consultants. Relative importance of the attributes was determined by a constant sum scale and multiple comparison tests. Results suggest that recreation and cultural amenities are less important than other factors such as cost of living and education. Several explanations are suggested as well as ideas for future research.
L'analyse de Fourier tient une place majeure dans l'analyse et la comprehension de nombreux phenomenes de la physique et de l'ingenierie contemporaines. Pourtant les etudiants, qui ont souvent decouvert cette notion a travers des travaux numeriques, ne cernent pas forcement toute la richesse qui peut etre tiree de l'analyse conjointe dans les do-maines temporels et spectraux, notamment dans le domaine de l'optique. Nous avons mis en place dans le cadre de la seconde annee du master Physique Lasers et Materiaux de l'Universite de Bourgogne une experience permettant d'insister sur ces notions et de montrer sur un exemple non trivial de modulation de phase periodique, les precautions a prendre dans l'interpretation des differents spectres accessibles experimentalement. Cette seance de travaux pratiques, rendue possible grâce a l'utilisation de l'infrastructure de recherche, constitue egalement une introduction a l'utilisation de materiel standard des telecommunications optiques.
