Search

Your search keyword '"Sumantyo, Josaphat Tetuko Sri"' showing total 267 results
Start Over Author "Sumantyo, Josaphat Tetuko Sri"
267 results on '"Sumantyo, Josaphat Tetuko Sri"'

7. RF System

Author

Chua, Ming Yam, primary and Sumantyo, Josaphat Tetuko Sri, additional

Published
2023
Full Text
View/download PDF

10. Peer-Review Statements

Author

Sumantyo, Josaphat Tetuko Sri, Pulungan, Nur Ainun Harlin Jennie, Miyahara, Taira, Cahyono, Ari, Prasetya, Angga, Ma, Wanshu, Series Editor, Sumantyo, Josaphat Tetuko Sri, editor, Pulungan, Nur Ainun Harlin Jennie, editor, Miyahara, Taira, editor, Cahyono, Ari, editor, and Prasetya, Angga, editor

Published
2023
Full Text
View/download PDF

11. Peer-Review Statements

Author

Sumantyo, Josaphat Tetuko Sri, primary, Pulungan, Nur Ainun Harlin Jennie, additional, Miyahara, Taira, additional, Cahyono, Ari, additional, and Prasetya, Angga, additional

Published
2023
Full Text
View/download PDF

15. Multi-Sensor Satellite to Assess Sea Level Rise and Land Subsidence Impact on the Flood Crisis on the East Coast of North Sumatra and Medan City, Indonesia

Author

Lumban-Gaol, Jonson, primary, Sumantyo, Josaphat Tetuko Sri, additional, Tambunan, Efendy, additional, Situmorang, David, additional, Antara, I Made Oka Guna, additional, Arhatin, Risti Endriani, additional, Osawa, Takahiro, additional, Sinurat, Maya Eria, additional, and Suhita, Ni Putu Asri Ratna, additional

Published
2023
Full Text
View/download PDF

25. Small baselines techniques of time series InSAR to monitor and predict land subsidence causing flood vulnerability in Sidoarjo, Indonesia

Author

Hayati, Noorlaila, Widodo, Amien, Kurniawan, Akbar, Sanjiwani, I Dewa Made Amertha, Darminto, Mohammad Rohmaneo, Yudha, Imam Satria, and Sumantyo, Josaphat Tetuko Sri

Subjects
General Earth and Planetary Sciences, General Environmental Science
Abstract

Floods are the most common sort of natural disaster that occurs when a body of water overflows and submerges on dry terrain. Several regions in Sidoarjo District, East Java such as Kedungbanteng and Banjarasri Village, have experienced floods with varying heights since 2018 due to heavy rainfall in the areas. According to the Meteorological, Climatological, and Geophysical Agency (BMKG), rainfall intensity in these areas reach 100 mm/day. Furthermore, the physical environment in both areas shows land subsidence that causes a change in the flow pattern, which triggers its occurrence. This research incorporated different small baseline techniques of InSAR time series analysis and used GPS measurement to evaluate and monitor the land subsidence in both areas. The reseachers used Sentinel-1 SAR data both from ascending and descending for the period between 2017 and 2021. The results showed significant subsidence value by up to −200 mm/year both in Kedungbanteng and Banjarasri Village, and GPS observation also confirmed approximately −3.2 cm of subsidence value during 2 months of sampling observations. Using the neural network analysis, the reseachers predicted the time series displacement for one year and showed that a continuous trend of deformation still existed.

Published
2022

27. Differentially Fed Dual-Band Base Station Antenna with Multimode Resonance and High Selectivity for 5G Applications

Author

Liu, Xuekang, Sanz-Izquierdo, Benito, Zhang, Haiwei, Gao, Steven, Hu, Wei, Yang, Xue-Xia, Sumantyo, Josaphat Tetuko Sri, Liu, Xuekang, Sanz-Izquierdo, Benito, Zhang, Haiwei, Gao, Steven, Hu, Wei, Yang, Xue-Xia, and Sumantyo, Josaphat Tetuko Sri

Abstract

A dual-polarized antenna with multimode resonance and high selectivity is proposed in this paper to cover the 5G sub-6 GHz bands. The proposed antenna achieves dual wide impedance bandwidth characteristics by incorporating a dual mode coupled patch and four planar coupled strips around the driven patch. Through the four resonant modes of these structures, the antenna effectively covers the two desired frequency bands. Moreover, the electric/magnetic coupling between the driven patch, dual mode coupled patch, and planar coupled strips enables the creation of three radiation nulls that suppress unwanted radiation. To further improve the out-of-band rejection level and half power beamwidth, four shorted strips are introduced around the radiator. The introduction of these strips results in a 4th radiation null at higher out-of-band frequencies and expands the antenna's half power beamwidth from 52° to 62°. To demonstrate the feasibility of the design, both the proposed antenna and its array were manufactured and tested. Measured results show that the filtering element was able to operate within frequency bands of 3.24-3.83 GHz (16.7%) and 4.74-5.30 GHz (11.2%) with a reference of |Sdd11| < -14 dB. The input ports exhibited a high level of isolation, measuring 40 dB. Furthermore, the four radiation nulls proved effective in suppressing out-of-band radiation.

Published
2023

29. Circularly Polarized Lunar Regolith Simulant Antenna for Future Communication and Remote Sensing in Lunar Environment

Author

Pramono, Subuh, Sumantyo, Josaphat Tetuko Sri, Ibrahim, Muhammad Hamka, Takahashi, Ayaka, Yoshimoto, Yuki, Kashihara, Hisato, Santosa, Cahya Edy, Gao, Steven, and Ito, Koichi

Abstract

This letter presents a novel substrate with lunar regolith simulant as a major material that closely resembles the properties of the lunar regolith. It aims to support the realization of antennas as telecommunication and remote sensing infrastructures that can serve communication and lunar observation services on the moon. Lunar regolith simulant substrate has a low-measured dielectric constant $({{\varepsilon }_r})$ of 2.08 and a dissipation factor (tan-δ) of 0.00527. The 2 × 2 CP antennas work at a center frequency of 6.175 GHz, use two-staked substrates, the serial-sequential-rotation (SSR) technique, and have a total size of 70 × 70 × 4 mm3. The antenna has a measured broad impedance bandwidth of 1.98 GHz (32%), an axial ratio bandwidth of 1.06 GHz (17%), and a peak gain of 11.6 dBic. The measured half beamwidth in the E-plane and H-plane are achieved at 82° and 81°, respectively. The antenna in full circularly polarized polarimetric modes is subjected to experimental scattering tests for the applications of communication and remote sensing. The measured scattering matrix is identical to the theoretical scattering matrix. The result shows that the lunar regolith has great potential as an antenna substrate to support future telecommunication and remote sensing infrastructure in the lunar environment.

Published
2023
Full Text
View/download PDF

36. Land resource analysis in Jakarta Special Province, Indonesia

Author

Kurniasari, Santi Dewina Inggar, Rahmawati Laelina, Muhammad Dzakwan Taufiq Nur, Laksono Agung, Maulidina Wisha Puti, Putri Ratih Fitria, Harini Rika, and Sumantyo Josaphat Tetuko Sri

Subjects
Environmental sciences, GE1-350
Abstract

The increasing number of Jakarta Special Province residents further increased the amount of land required for daily usages. In order to maintain and improve the economy, agricultural land-use continued to be converted into non-agricultural land-use. The reduced amount of agricultural land-use was able to increase the population pressure on said land, surpassing the land carrying capability. Analyzing the remaining land resources of Jakarta Special Province aimed to understand the changes in land-use, land carrying capability, the scale of land resources, and to determine the population pressure of the residents of Jakarta Special Province. The methods used in this analysis was to use secondary data, presented in the form of tables, graphs, and maps, as well as quantitative and qualitative descriptive analysis. In general, Jakarta Special Province had experienced a conversion of agricultural land-use into non-agricultural land-use (e.g. residential and industrial) between the year 2010 to 2018. The number of residents had exceeded the carrying capacity of Jakarta’s land. This resulted from a growing need for non-agricultural land as well as the amount of population pressure, causing the unmet settlement needs.

Published
2020
Full Text
View/download PDF

46. A Mutual-Coupling-Suppressed Dual-Band Dual-Polarized Base Station Antenna Using Multiple Folded-Dipole Antenna

Author

Liu, Xuekang, Gao, Steven, Sanz-Izquierdo, Benito, Zhang, Haiwei, Wen, Lehu, Hu, Wei, Luo, Qi, Sumantyo, Josaphat Tetuko Sri, Yang, Xue-Xia, Liu, Xuekang, Gao, Steven, Sanz-Izquierdo, Benito, Zhang, Haiwei, Wen, Lehu, Hu, Wei, Luo, Qi, Sumantyo, Josaphat Tetuko Sri, and Yang, Xue-Xia

Abstract

An interleaved shared-aperture dual-band dual-polarized base station array antenna is proposed in this paper. The lower-band (LB) element is realized by using a multiple folded-dipole antenna (MFDA) and four parasitic loops. To interpret the working principle of the MFDA, a double folded-dipole antenna (DFDA) is firstly analyzed by using the transmission line model. Then, by combining two bended DFDAs and introducing four parasitic loops, a low cross-band scattering LB element with a high out-of-band rejection level of 16 dB is obtained to cover 2.3-2.7 GHz. The higher-band (HB) element with a wide impedance bandwidth of 42.5% (3.0-4.6 GHz), a high roll-off rate (RoR) of 249.2 dB/GHz, and a high out-of-band rejection level of 17 dB is obtained by introducing a meander line loop, a rectangular loop and V-shaped strips near the dipole arms. By combining the proposed low scattering low-pass LB element and the high RoR high-pass HB element, a novel interleaved shared-aperture dual-band dual-polarized array antenna with a small frequency ratio of 1.46 and a high cross-band isolation level of 25 dB is realized. Due to the low-scattering characteristic and filtering response of the LB element, the radiation patterns of the wideband HB sub-arrays are almost unaffected.

Published
2022

50. Effect of smoothing filter on continuous time domain in advanced consecutive DInSAR.

Author

Nishi, Katsunoshin, Kawai, Masaaki, Cahyono, Bowo Eko, Waqar, Mirza Muhammad, and Sumantyo, Josaphat Tetuko Sri

Subjects
SYNTHETIC aperture radar, GLOBAL Positioning System, ORBITS (Astronomy), MOVING average process
Abstract

Eliminating ionospheric and/or atmospheric errors from SAR images is very important to improve the detection capability of interferometric SAR. In this study, we showed the improvement of the detection ability of the advanced Consecutive DInSAR method by applying the smoothing filter on continuous time domain, which is performed by the moving average method. The analytical accuracy of the Advanced Consecutive DInSAR was verified using Sentinel-1 and GNSS(Global Navigation Satellite System) data. The error reduction was occurred clearly from the 3 pairs images in the continuous time in the descending and ascending orbits. The RMSEs were decreased by 0.28 cm and 0.36 cm at the maximum for the descending and the ascending orbits, respectively, compared to no-using the filter. In the future, more highly accurate land deformation detection is expected by applying the smoothing filter on continuous time domain in the advanced Consecutive DInSAR. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results