AC voltage regulation of a bidirectional high-frequency link converter using a deadbeat controller

This paper presents a digital controller for AC voltage regulation of a bidirectional high-frequency link (BHFL) inverter using Deadbeat control. The proposed controller consists of inner current loop, outer voltage loop and a feed-forward controller, which imposes a gain scheduling effect according to the reference signal to compensate the steady-state error of the system. The main property of the proposed controller is that the current- and the voltage-loop controllers have the same structure, and use the same sampling period. This simplifies the design and implementation processes. To improve the overall performance of the system, additional disturbance decoupling networks are employed. This takes into account the model discretization effect. Therefore, accurate disturbance decoupling can be achieved, and the system robustness towards load variations is increased. To avoid transformer saturation due to low frequency voltage envelopes, an equalized pulse width modulation (PWM) technique has been introduced. The proposed controller has been realized using the DS1104 digital signal processor (DSP) from dSPACE. Its performances have been tested on a one kVA prototype inverter. Experimental results showed that the proposed controller has very fast dynamic and good steady-state responses even under highly nonlinear loads

Tracking human movement in office environment using video processing

In this paper, we proposed an approach of multi-person movement tracking in office environment without any identity conflicts. Simple image processing with frame differentiation method is applied to identify multiple human motion. An Expert System is applied to predict next camera occurrence of the tracking human. The main objective of this work is to detect and track multi-human motion using single camera in more than a room in an office

Pengaruh Temperatur terhadap Pembentukan Pori Arang Cangkang Sawit sebagai Adsorbansi

Had been conducted to influence temperature in burning process for getting carbon (C) and palm shell pore, that\u27s important to explore activated carbon otherwise useful for absorption. Carbonization process had been done for palm shell became activated carbon product varied with temperature to know the difference. Carbonization process had done with vacuum furnace with temperature 500 oC and 1000 oC, each as 40 minutes. During carbonization process, many smoke out at temperature 500 oC and after temperature 1000 oC no anymore smoke out. After that condition, it will getting activated carbon and thus it will done testing laboratory XRF to determine the composition. Testingresult shows that forming the graphite phase to all carbon obtained result content of carbon to high enough as 48 % for 500 oC and 50 % for 1000 oC. Testing Laboratory for SEM shows that for forming porous size was obtained 10 μm for 500 oC and 5 μm for 1000 oC. Temperature higher will getting large amount porous palm shell. Large amount active palm shell will good for using as absorber

Identification of Phytophthora spp. from perennial crops in Malaysia, its pathogenicity and cross-pathogenicity

Phytophthora is one of the most important plant pathogens of perennial crops in the tropics. This study characterised the pathogen(s) responsible for cocoa black pod rot, rubber pod rot and durian stem canker. Eighteen Phytophthora isolates were collected from several states in Malaysia, namely Pahang, Johor and Selangor. A total of 12 Phytophthora palmivora and six Phytophthora nicotianae isolates were isolated and identified based on the morphological and molecular characteristics. Internal transcribed spacer (ITS) sequences enabled Phytophthora identification to species level. Inoculation of 18 isolates on detached leaves and unripen cocoa pods successfully demonstrated the progressive development of lesions on its original host. Lesions were also observed in all wounded detached leaves of young durian (clone D24) and rubber (clone RRIM600) and unripen cocoa pods (clone BAL244) regardless of host and isolates. Phytophthora isolates from durian (DSCI) and rubber (R4A) used to inoculate cocoa pods exhibited lesion sizes of 11.6±0.75 and 9.6±0.64 mm, respectively. However, Phytophthora isolates from cocoa (CPR25) developed a longer length of lesion of 18.6±0.47 mm. On durian leaves, Phytophthora isolate from rubber (R4A) and cocoa (CPR25) recorded 11.73±1.04 and 5.22±0.57 mm length of lesion while Phytophthora isolates from durian (DSCB4) produced 13.13±1.29 mm lesion on its native host. Isolates from cocoa (CPR22) and durian (DSCE3) infected rubber leaves with 3.74±0.48 and 2.55±0.31 mm length of lesion, in comparison to rubber isolates (R1B) with 5.43±0.23 mm length of lesion. Differences in the length of lesion demonstrated higher level of virulence on the native host

Deskripsi Pisang Beranga Pada Dua Habitat Yang Berbeda

This research was conducted from September to December 2005 in Ende (Flores) and Kupang (Timor). The aims of this research were to describe the morphology of growth of banana and production of banana fruits especially variety of Baraga, identify the environment of growth, and analyze the nutrient content of fruits, especially, variety of Baraga, cultivated in the two different locations. The morphology growth of Baraga cultivated in Ende was rapidly than Baraga cultivated in Kupang. The contents of vitamin C, fat, and protein showed significant differences. These differences possibly were caused by the different characteristic of land geomorphology, main material of landform, fertility of soil, especially, pH and availability of phosphor

Morphologies of Nanostuctured ZnO prepared by matrix-assisted method and its effects on photocatalytic activity

Zinc oxide nanoparticles have been successfully synthesized by matrix-assisted method using activated carbon as a matrix and zinc nitrate and zinc acetate as ZnO precursors. Different weight percentages (10-40 wt %) of Zn precursor were loaded onto activated carbon and calcined in air at 500 and 600 ºC, producing highly crystallined ZnO particles with a wurtzite structure. Nanospherical ZnO and a mixture of nanosphere and nanorod ZnO were produced from zinc nitrate and zinc acetate, respectively. The efficiency study of the synthesized ZnO in the photodegradation of rhodamine 6G indicated that ZnO produced from zinc acetate is more effective than that from zinc nitrate, possibly due to the differences in the morphology of the synthesized ZnO

Persepsi Masyarakat Desa Sungai Awan Kanan terhadap Keberadaan Hutan Mangrove di Kawasan Pantai Air Mata Permai Kabupaten Ketapang

Mangrove forest in the coastal area of Air Mata Permai is one source of the livelihood of local people. The relation between communities and the existence of mangrove forests has led to the perception of the communities as an effort to maintain and to conserve mangrove forests. This research objective is to look communities perception of the SAK Village to the presence of mangrove forests in the coastal area of Air Mata Permai district Ketapang and the factors that affect. The method used in this research is a survey method and technique of sampling or interviews with respondents conducted by purposive sampling. The number of respondents in this research is 90 respondents. The results showed the level of communities perception of SAK Village to the existence of mangrove forests in the coastal area Air Mata Permai tends to higher as many 52 respondents (57.78%) had a high perception, 25 (27.78%) of respondents have the perception medium and 13 respondents (14.44%) have a low perception. Mangrove forest in the coastal area of Air Mata Permai is one source of the livelihood of local people. The relation between communities and the existence of mangrove forests has led to the perception of the communities as an effort to maintain and to conserve mangrove forests. This research objective is to look communities perception of the SAK Village to the presence of mangrove forests in the coastal area of Air Mata Permai district Ketapang and the factors that affect. The method used in this research is a survey method and technique of sampling or interviews with respondents conducted by purposive sampling. The number of respondents in this research is 90 respondents. The results showed the level of communities perception of SAK Village to the existence of mangrove forests in the coastal area Air Mata Permai tends to higher as many 52 respondents (57.78%) had a high perception, 25 (27.78%) of respondents have the perception medium and 13 respondents (14.44%) have a low perception. Keywords: Mangrove Forests, local communities, ccosystems and perception. Keywords: Mangrove Forests, local communities, ccosystems and perception