| Judul | Abstract | Halaman |
|---|
| Combination of Minimum-Maximum (m-m) Attribute and Zero-INTENS-Difference (z-i-d) Attribute for Estimating Seismically Thin-Bed Thickness | This paper demonstrates a new alternative way in estimating seismically thin-bed (below-tuning) thickness. Initial thickness is built by bandpass filtering the amplitude display of a zero-phase seismic. The filter removes the non minimum and or non maximum and left the maximum and or the minimum of seismic amplitude. The unresolved below-tuning thickness is then corrected by zero-INTENS-difference (z-i-d) attribute. INTENS is integrated energy spectra, an attribute which can be derived from spectral analysis. z-i-d attribute is zero difference of INTENS between the seismic and its synthetic. The method generates INTENS difference profile by subtracting seismic INTENS and its synthetic INTENS iteratively. The iteration is controlled by dipole space shifting from distance to closer or vice versa. The true thickness is derived by locating z-i-d which laid in INTENS different profile. It has found that, for free noise true seismic and perfect-wavelet (a wavelet which only approximately similar with wavelet which constructing the true seismic) synthetic seismic, in INTENS different profile, the z-i-d location always corresponds to true dipole space or thickness. The method could resolve all thickness of a wedge-modeled seismic with three different dominant frequencies. When the synthetic seismic is constructed with imperfect wavelet, slightly different analysis is needed to locate z-i-d attribute and the result is not as perfect as when perfect wavelet constructing synthetic seismic. A quiet similar result is got when the method is implemented for noisy wedge-modeled seismic. Bad thickness estimation is resulted for 20% noise seismic. The method algorithm is extended for similar dipole polarity model and multilayer model to bring the method to real seismic data nearer. The extension is done by estimating thickness of every layer of a stacked-wedge-modeled seismic. The algorithm then generalized for estimating layers thickness with several thickness combinations. The method was able to delineate shallow channel of Stratton Field by providing good pseudo-acousticimpedance (pseudo AI) map. | 79-100 |
| Autonomous Coastal Land Cover Assessment Using Polarimetric Decomposition of SAR Data | The paper reports an experiment on classification using fully polarimetric SAR data. Many reports have been presented mentioning test sites in temperate regions utilizing polarimetric SAR data from airborne and/or spaceborne SAR sensors. However, few studies are dedicated to tropical region which highly dynamic land uses are observed. Using the AirSAR Sungai Wain fully polarimetric data, capability to extract features in coastal region has been demonstrated by an unsupervised classification technique fed by the CloudePottier decomposition theorem. | 101-112 |
| Synthesis of γ-Al2O3 Catalyst Support from Kaolin of Indonesian Origin | Kaolin has been identified as a potential raw material for the production of γ-Al2O3 for hydrotreating catalyst support. This work explores the technical feasibility of applying the potassium hydroxide (KOH) e xtraction synthesis route on kaolin from the Belitung Island in Indonesia. The application of a published synthesis method to Belitung kaolin requires an approximately twofold increase in kaolin calcination time, an increase in kaolin calcination temperature from 950 to 1000 °C, and a tenfold increase in metakaolin extraction time, to obtain a specific surface area higher than 200 m2/g. The highest specific surface area of 233 m2/g was obtained when the kaolin was calcined at 1000 °C for 24 hours, and the metakaolin was extracted by concentrated KOH solution for 12 hours. Phase characterization of the final product confirmed the formation of γ-Al2O3, but with the inclusion of low-surface area γ-Al2O3 phase. | 113-126 |
| An LMI Approach to H∞ Performance Analysis of Continuous-Time Systems with Two Additive TimeVarying Delays | This paper investigates the problem of H∞ performance analysis for continous–time systems with two additive time -varying delays in the state. Our objective is focused on stability analysis of a continuous system with two timevarying delays with an H∞ disturbance attenuation level γ. By exploiting Lyapunov-Krasovski functional and introducing free weighting matrix variables, LMI stability condition have been derived. | 127-138 |
| A New Voltage Control Method for Single-Phase PWM Inverters | A new voltage control method for single-phase full-bridge PWM inverters that having an output LC filter is proposed in this paper. The proposed voltage controller has a capability to realize a zero steadystate output voltage error with fast response. The zero steady-state output voltage error is achieved by using a controller that is derived by using the virtual LC resonant circuit. Fast response is obtained by using a virtual resistance that is connected in parallel with the filter capacitor. The validity of the proposed method is verified by experimental results. | 139-152 |
| Sorption and Degradation Capacity of Natural Estrogens in Freshwater Environmental System in Japan | The sorption and the degradation capacity of natural estrogens in freshwater environmental system in Japan were performed. Batch experiments were examined in water-sediment suspensions using six layers of sediment under aerobic and anaerobic conditions. The results indicated that the water-sediment partition coefficient of E1 (KdE1) was higher than E2 (KdE2). The degradation rate of E1 (kE1) was smaller than E2 (kE2). Under aerobic and anaerobic conditions, E1 was formed from E2. The degradation rate of E2 (kE2) from the surface to bottom of sediment layers was estimated fell in the range from 0.114 to 0.026 h-1 and 0.05 to 0.014 h-1 under aerobic and anaerobic conditions, respectively. | 153-160 |
