Hasil Pencarian  ::  Simpan CSV :: Kembali

"The electromagnetic wave propagation in the mobile communication environments can be predicted by using ray tracing approach which incorporates reflection and diffraction. However, the ddiffuse scatering effects are often non-negligible in the experiment, since the roughness of the building surfaces is comparable with or larger than wavelength.In this paper we present Method of Moments (MOM) analysis of the scattering from the 2D rough surface model of the building. The fluctuation of the field strength due to the change of the specular reflection point on the surface has been evaluated by statistical properties (the cumulative distribution and the autocorrelation). The effects of the incident angle and frequency are also studied."

"This book focuses on recent developments in the area of seismic wave propagation and scattering through the randomly heterogeneous structure of the earth, with emphasis on the lithosphere. The presentation combines information from many sources to present a coherent introduction to the theory of scattering in acoustic and elastic materials and includes analyses of observations using the theoretical methods developed. The second edition especially includes new observational facts such as the spatial variation of medium inhomogeneities and the temporal change in scattering characteristics and recent theoretical developments in the envelope synthesis in random media for the last ten years."

"Cloud propagation over Sumatra and the surrounding area (10S-10N, 70-120E) during the Coupling Processes inthe Equatorial Atmosphere-I (CPEA-I) campaign (10 April to 9 May 2004) was tracked using brightness temperature(Tb) data from the GOES-9 satellite. The cloud tracking was based on three-dimensional data with a threshold of Tb <210 K. During the campaign, westward-moving clouds were more dominant than eastward-moving systems, with a ratioof approximately 4:1. This characteristic coincided with the dominant easterly wind aloft. Most clouds propagated witha speed varying between 4 and 35 m/s, with a mean value of 13.7 m/s. If the westward and eastward propagations wereseparated, the average duration, speed, and span of the westward (eastward) moving clouds are 7.7 (5.8 h), -14.5 (9.8m/s), and 435.5 (187.1 km), respectively. The characteristics of cloud propagation during the CPEA-I were influencedby environmental factors such as relative humidity, temperature, the vertical movement of air, and wind shear. Suchfactors interacted with the inactive and active phases of the Madden-Julian Oscillation.Statistik Pergerakan Awan di Sumatera Selama CPEA-I. Karakteristik awan konvektif di Sumatera dan daerahsekitarnya (10LS-10LU, 70-120BT) selama proyek Coupling Processes in the Equatorial Atmosphere-I (CPEA-I)dari 10 April hingga 9 Mei 2004 telah diteliti menggunakan data brightness temperature (Tb) dari satelit GOES-9.Metode pelacakan pergerakan awan memanfaatkan data Tb tiga dimensi dengan nilai ambang <210 K. Secara umumpergerakan awan ke arah barat lebih banyak dari pada pergerakan ke timur, dengan perbandingan 4:1. Hal ini konsistendengan dominannya angin yang berhembus ke barat pada atmosfir atas. Sebagian besar awan bergerak dalam rentangkecepatan 4?35 m/s dengan kecepatan rata-rata 13,7 m/s. Pergerakan ke barat secara berturut-turut memiliki rata-rataumur, kecepatan, dan jarak penjalaran sekitar 7,7 jam, -14,5 m/s, dan 435,5 km sedangkan untuk awan yang ke timursecara berturut-turut adalah 5,8 jam, 9,8 m/s, dan 187,1 km. Hasil analisis menunjukkan pergerakan awan selamaCPEA-I dipengaruhi oleh faktor lingkungan seperti: kelembaban, temperatur, pergerakan udara ke atas, dan pergerakanangin yang berinteraksi dengan fase tidak aktif dan aktif osilasi Madden-Julian yang terjadi selama CPEA-I."

"This exceptional book introduces the reader to the principles, theory and applications of physical layer wireless/mobile communications. In the area of wireless, the antennas, propagation and the radio channel used are interrelated; this book offers an explanation of that relationship which is fundamental to the development of systems with high spectral efficiency.The book emphasises the basic principles needed to establish an understanding of this technology. However, the tools required - such as the mathematics and statistics - are treated in the manner of a practical handbook, avoiding detailed derivations. The reader will develop a clear insight into the physics and effects of multipath and the use of multipath channels for communications. Propagation modelling, simulation and measurement, scattering, antenna principles, array antennas, adaptive antennas and smart antennas are also covered."

"Penelitian ini mengkaji tentang potensi bahaya tsunami di Kecamatan Bayah, Kabupaten Lebak yang berbatasan langsung dengan Samudra Hindia, tempat zona subduksi berada. Kecamatan Bayah berhadapan dengan zona subduksi Megathrust Selat Sunda yang memiliki potensi kekuatan maksimum gempabumi sebesar 8.7 Mw berdasarkan penelitian oleh Pusat Studi Gempa Nasional (PuSGeN). Tujuan dari penelitian ini adalah memodelkan perkiraan tsunami yang terjadi di Kecamatan Bayah berdasarkan potensi gempabumi di zona megathrust segmen Selat Sunda. Metode yang digunakan berupa pemodelan numerik tsunami menggunakan perangkat lunak COMCOT V1.7 dengan skenario gempabumi sebesar 8.7 Mw. Terdapat 2 skenario pemodelan yang dilakukan, skenario 1 menggunakan layer resolusi tinggi dan skenario 2 menggunakan layer dengan resolusi lebih rendah. Berdasarkan dari analisis hasil pemodelan menggunakan COMCOT V1.7 diketahui waktu yang dibutuhkan gelombang tsunami pertama dari episenter menuju Kecamatan Bayah berkisar antara 15 – 19 menit dengan ketinggian gelombang tsunami berkisar dari 6.5 – 18.9 meter mengikuti pola topografi ketinggian wilayah. Rata – rata kedalaman rendaman air yang terjadi berkisar antara 6 – 10 meter (skenario 1) dan 0.5 – 3 meter (skenario 2). Luas area yang tergenang mencapai 951.08 ha (skenario 1) dan 645.78 ha (skenario 2) dengan Jarak inundasi maksimun tsunami sejauh 3.7 km (skenario 1) dan 1.8 km (skenario 2). Potensi bahaya tsunami di Kecamatan Bayah termasuk dalam kategori tinggi mengingat ketinggian tsunami yang terjadi mencapai lebih dari 3 meter dari permukaan.

---

This research examines the potential danger of tsunamis in Bayah District, Lebak Regency, which borders directly with the Indian Ocean, where the subduction zone is located. Bayah District faces the Megathrust Subduction Zone of the Sunda Strait which has a maximum earthquake strength potential of 8.7 Mw, according to research by the National Earthquake Study Center (PuSGeN). This study aims to model the estimated tsunami in the Bayah District based on the earthquake potential in the megathrust zone of the Sunda segment. The method used is numerical tsunami modeling using COMCOT V1.7 software with an earthquake scenario of 8.7 Mw. There are two modeling scenarios carried out; scenario 1 uses high-resolution layers, and scenario 2 uses layers with lower resolution. Based on the analysis of modeling results using COMCOT V1.7, it is known that the time required for the first tsunami wave from the epicenter to Bayah District ranges from 15 – 19 minutes, with a tsunami wave height ranging from 6.5 – 18.9 meters following the topographic pattern of the region's elevation. The average water immersion depth ranges from 6 – 10 meters (scenario 1) and 0.5 – 3 meters (scenario 2). The area submerged reaches 951.08 ha (scenario 1) and 645.78 ha (scenario 2), with a maximum inundation distance of 3.7 km (scenario 1) and 1.8 km (scenario 2). The potential danger of tsunamis in Bayah District is included in the hazardous category considering that the height of the tsunami that occurs reaches more than 3 meters from the surface."