Forecasting of global horizontal irradiance by exponential smoothing, using decompositions

Time series methods are frequently used in solar irradiance forecasting when two dimensional cloud information provided by satellite or sky camera is unavailable. ETS (exponential smoothing) has received extensive attention in the recent years since the invention of its state space formulation. In this work, we combine these models with knowledge based heuristic time series decomposition methods to improve the forecasting accuracy and computational efficiency.<p></p> In particular, three decomposition methods are proposed. The first method implements an additive seasonal-trend decomposition as a preprocessing technique prior to ETS. This can reduce the state space thus improve the computational efficiency. The second method decomposes the GHI (global horizontal irradiance) time series into a direct component and a diffuse component. These two components are used as forecasting model inputs separately; and their corresponding results are recombined via the closure equation to obtain the GHI forecasts. In the third method, the time series of the cloud cover index is considered. ETS is applied to the cloud cover time series to obtain the cloud cover forecast thus the forecast GHI through polynomial regressions. The results show that the third method performs the best among three methods and all proposed methods outperform the persistence models.<p></p&gt

Solubility of Rock Phosphate and SP-36 in Peat Soils Amended with Mineral Soil

Rock phosphates application on peat soil has a good prospect because of its high solubility in acid condition. However, the study of the solubility of rock phosphate in peat soils is still limited. This study aimed to quantify the solubility of rock phosphate and the effects of some sources of rock phosphates and SP-36 in the peat soils, taken from South Sumatera amended with mineral soil. The study was conducted in the laboratory ofIndonesian Soil Research Institute, in Bogor. The study consisted of two activities: 1) study on the solubility of some rock phosphates (Marocco, Christmas, and Ciamis) in peat soils. For this study a 100 g of oven dried (105oC) peat soil for each treatment was used for this study. The treatments were eleven levels of P i.e. 0, 10, 20, 30, 40, 50, 60, 75, 100, 125, and 150 ppm P applied to dried peat soils. The treated peat soils werethen incubated for 2 weeks before analyses of soluble P was conducted. The molybdat blue method was used to analyze the samples at 2, 4, 8, and 12 weeks after the incubation. 2) The second study i.e. the application of some rock phosphates or SP-36 on the peat soils amended with mineral soils, four levels of P (25, 50, 74, and 100% of P sorption) plus partial and complete control treatments have been replicated twice. Two hundred grams of oven dried peat soils (105oC) amended with mineral soils at 7,5% maximum Fe sorption, incubated for four weeks, and then soluble P was analyzed using molybdat blue at 1, 2, 4, 6, 8, 10, and 12 weeks after incubation. The results showed that the order of rock phosphates solubility in peat soils was Marocco> Ciamis>Christmas. The solubility of P in peat soils amended with mineral soil and rock phosphates gave similarresults as rock phosphate was in the order of SP-36>Marocco>Ciamis> Christmas. Soluble P increased up to 8 weeks of incubation, and then decreased. The effect of soil mineral ameliorant and some rock phosphates application of soluble P at 12 weeks after the incubation around 15.7-34.2 ppm P. Rock phosphates that has high reactivity gave a high Psolubility on peat soils so it that can be used as P sources in the peat soil

Pengaruh Regulasi Dan Ketersediaan Anggaran Terhadap Kinerja Pelayanan Aparatur Skpd Dan Implikasinya Pada Kualitas Pelayanan Publik Di Provinsi Aceh

Human resource take the strategy position among the other resource in organization/institution. But in reality, there are still many organitations do not cosider the important thing of the human resource for organization sustainable. Therefore, many enterprises officers and viewed as the most important asset of organization. The improvement of the workers quality in many institution are hoped to be able in increasing the social service. The result of survey contemporary, showed that there are still many problems in Aceh province such as ; the weaknesses for the competativeness nationally. The management of institution (Good Govermence) is hot running well. The understanding of regulation and its implementation is still very limited. The quality of the goverment officer, and the process to develop the human resources in Aceh are not still running well. This research is focused on the impact of the regulation and the budget availability which able to increase the public service in five districts of Aceh province. The result of this research showed that a good regulation and its implumentations, it will have significant constribution and its influence toward the public service around 15,16%. While a good budget avaibility and its implumentation toward the public service, it will give a significant contribution toward the officer service and its influence around 25

Regional validation of retracked sea levels from SARAL/Altika over the South China sea and adjacent seas

This paper focuses on assessing the quality of sea level anomaly (SLA) data from the new generation of Ka-band SARAL/AltiKa satellite altimetry over the continental shelf of the South China Sea. The region consists of peninsulas, shallow seas, and small islands that produce complicated altimetric waveform patterns. The improved-accuracy of SLAs data from the MLE4, Ice1 and Ice2 retrackers which are provided in the AVISO-Sensor Geophysical Data Records (SGDR) were optimized in this study. The quality of retracked SLAs is assessed by making comparison with tide gauge data from six stations. In general, the percentage of data availability of Ice-1 retracker is superior ( > 68%) to those of MLE- 4 and Ice-2 retrackers. The improvement of percentage (IMP) also shows that Ice-1 retracker improves the standard deviation > 12% better than those of Ice-2 retracker. Over complex areas of Lubang and Ko Taphao Noi, the temporal correlation of Ice-1 retracker is superior (r > 0.80) to those of MLE4 and Ice-2 retrackers (r 5.8) and lower RMS error ( < 34 cm) than those of Ice-1 retracker. It can be concluded that the Ice-1 and Ice-2 retrackers were superior for the coastal region of Maritime Continent

Characterization of defect induced multilayer graphene

A study of oxygen plasma on multilayer graphene is done with different flow rates. This is to allow a controlled amount of defect fabricated on the graphene. Results from the study showed that the intensity ratio of defect between D peak and G peak was strongly depended on the amount of oxygen flow rate thus affected the 2D band of the spectra. The inter-defect distance LD ≥ 15 nm of each sample indicated that low-defect density was fabricated. The surface roughness of the multilayer graphene also increased and reduced the conductivity of the multilayer graphene

Can computer assisted diagnosis (CAD) be used as a screening tool in the detection of pulmonary nodules when using 64-slice multidetector computed tomography?

Objectives:To evaluate (1) whether or not the addition of computer-assisted diagnosis (CAD) to 64-slice multidetector computed tomography (CT) can be used as a screening tool for detection of pulmonary nodules in routine CT chest examinations and (2) whether or not to advocate the incorporation of CAD as a screening tool into our daily practice. Materials And Methods: A retrospective cross-sectional analysis of 109 consecutive Patients who had all undergone routine contrast-enhanced CT chest examinations for indications other than lung cancer at the Radiology Department of Aga Khan University Hospital, Karachi, between November 2010 and January 2011. All examinations were evaluated in terms of the detection of pulmonary nodules by a consultant radiologist and CAD (ImageChecker CT Algorithm R2 Technology) software. The ability of CAD software to detect pulmonary nodules was evaluated against the reference standard. In addition, a chest radiologist also calculated the number of pulmonary nodules. The sensitivity and specificity of the CAD software were calculated against the reference standard by using a 2 * 2 table. The Mann-Whitney U test was applied to compare the performances of CAD and the radiologist. Results: CAD detected 610 pulmonary nodules while the radiologist detected only 113. The reference standard declared 198 pulmonary nodules to be true nodules. CAD detected 95% of all true nodules (189/198), whereas the radiologist detected only 57% (113/198). In the detection of true pulmonary nodules, CAD had 98% sensitivity compared with the radiologist who had 57% sensitivity, the statistical difference between their performances had a P value Conclusion: Considering the high sensitivity of CAD to detect nearly all true pulmonary nodules, we advocate its application as a screening tool in all CT chest examinations for the early detection of pulmonary nodules and lung carcinoma

The Development of Advanced Materials - High Performance Properties of Composite for Automotive and Aerospace Applications

Magnesium metal matrix composite (MMC) is an excellent candidate for moving engine components and airframes due to its low density. Magnesium's lightweight and natural affinity for wetting to ceramic particle reinforcements such as silicon carbide (SiC) make it one of the best choices as a matrix metal. However, magnesium alone without reinforcement is not suitable for mechanical applications due to its low wear resistance performance. The magnesium matrix composites used in this study were produced by powder metallurgy technique. The wear resistance of SiC/AZ91 composite reinforced with 0, 5, 10, 15 and 20 wt.% SiC were studied. Pin-n-disk dry sliding wear tests were carried out to study the volumetric wear, wear rate and wear mechanisms. The magnesium matrix composites were used as pins while the counter face consisted of mild steel disks. Worn surfaces of pins and the wear debris were investigated by using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDX). The wear resistance performance of magnesium matrix composites was found to improve with increasing volume fraction of SiC. Volumetric wear was found to increase with sliding distance and the wear rate was greatly reduced after the wear-in phenomenon. For AZ91 Mg-SiCp/ steel dry sliding wear system, 2D-wt.% SiC/AZ91 magnesium composite was found to have the best wear resistant performance. During the wear-in period, abrasion was predominant during the wear-in stage. In the corrosion study, corrosion behavior of Mgbased metal matrix composites SiC particulate reinforced AZ91 (SiC/AZ91) with reinforcement weight fraction of 5, 10, 15 and 20 wt.% as well as the monolithic AZ91 alloy was studied. The galvanic effect of SiC reinforcement on the matrix alloy was also investigated. The studies were carried out under temperature of 30° ± 1°C and pH 7 in aerated 0.1 M NaCI solution. The materials were studied by using electrochemical corrosion test, weight-loss measurement of corrosion rate, elemental analysis, X-ray diffraction and microscopic examination. The corrosion rates of the composites increased with the increase of SiC weight fraction. The significance of galvanic effect of SiC on the matrix alloy was proven where intersection of superimposed Tafel curves between sintered SiC and monolithic AZ91 occurred at higher corrosion current density (i...,) and lower corrosion potential (E...,). The corrosion was found localized at low SiC weight fraction, and gradually change to general corrosion. The corrosion rates of the composites were at least three times higher than the monolithic AZ91, due to galvanic effect of SiC on the matrix alloy and detachment of SiC particles from the materials

Urban runoff quantity and quality control – Malaysian perspective.

continued to increase at the urban areas in Malaysia. Such deteriorating trend was linked to increased land conversion activities, rapid disposal concept of drainage systems, main target on the control of point pollution sources (municipal and industrial wastewater) only, illicit connections and discharge of untreated sullage (grey-water) to the drainage systems. Realizing the limitations of the past efforts, various initiatives are taken in the recent pasts to improve the flood mitigation measures and river water quality throughout the country. Quantity and quality control of urban runoff is one of the most significant initiatives taken by the government of Malaysia. The significance of urban runoff quantity and quality control is gaining recognition throughout the country since the endorsement of Urban Stormwater Management Manual for Malaysia (USMMM), which was mandated in June 2000 by the Ministry Cabinet. It is now being applied for urban land development approval. The Manual consists of detailed engineering procedures and guidelines for runoff quantity control and treatment of non-point (diffuse) source pollutants. Receiving response from various stake-holders during the last 10 years, the government has taken another initiative to further improve the USMMM and prepare Standard Books for the legal enforcement of the runoff quantity and quality control. Such initiative by the government is highly expected to assist regulatory authorities and practitioners to reduce urban runoff related problems (flash flood and diffuse pollution) from the municipalities and help achieve the target of improved in river water quality nationwide. Various types of structural and non-structural best management practices (BMPs) are proposed in the manual. All stakeholders are working together to adopt the BMPs recommended in the USMMM. Lack of nationwide data on runoff quality from various landuses and local performance data of the structural best management practices (BMPs), are the main constraints the authorities are focusing on. The initiatives taken by the government of Malaysia can be a model for other developing nations in controlling runoff quantity and quality from urban areas. This paper briefly overviews the background of the urban runoff (both quantity and quality) management practices highlighting the issues regarding its implementation and improvement