KOMPARASI ALGORITMA DENGAN PENDEKATAN RANDOM UNDERSAMPLING UNTUK MENANGANI KETIDAKSEIMBANGAN KELAS PADA PREDIKSI CACAT SOFTWARE

Testing is a process that becomes a standard in producing quality software. In predictions of software defects, prediction errors are very bad. Incorrect and inappropriate data sets result in inaccurate prediction results will be affect the software itself. This study aims to overcome the problem of class imbalance with the software defect prediction data set, through the Random Undersampling (RUS) data level approach by taking several algorithms namely Naive Bayes (NB), J48 and Random Forest (RF) which aims to compare the accuracy level highest so that maximum results are obtained in the process of predicting software defects. From the results of this study it can be found that to overcome class imbalances using the Random Undersampling level data approach to predict software defects, the highest level of accuracy is obtained by the Random Forest algorithm with an accuracy rate of 71.932%

Activated biochar supported iron-copper oxide bimetallic catalyst for degradation of ciprofloxacin via photo-assisted electro-Fenton process: A mild pH condition

Iron-copper oxide impregnated NaOH-activated biochar (FeCu/ABC) was successfully fabricated through simple pyrolysis of activated biochar, followed by the impregnation method. The catalytic activity of the bimetallic catalyst was investigated for ciprofloxacin (CIP) degradation through a heterogeneous photo-electro-Fenton process at natural pH. The characterization analyses verified the structural suitability of as-synthesized FeCu/ABC to act as a catalyst for treating CIP. The effects of operating parameters such as Cu/Fe mass ratio, initial pH, catalyst dosage, electrical current and initial concentration of CIP were carefully studied. Complete removal of CIP concentrations of up to 45 mg/L was obtained after 2 h of reaction at Cu/Fe mass ratio of 1:1, pH 5.8, catalyst dosage of 1 g/L, and electrical current of 400 mA. CIP decay followed pseudo-first-order reaction kinetics. The synthesized heterogeneous catalyst exhibited a remarkable catalytic activity at natural pH (92 % mineralization of CIP after 8 h under the optimum conditions). The prepared catalyst possessed great stability and structural integrity for 5 consecutive runs. Furthermore, from a practical point of view, the catalyst exhibited an acceptable performance by oxidizing CIP dissolved in various water matrices such as tap water, river water, and a real sample of wastewater. The possible CIP degradation pathways were also proposed based on the identification of different oxidation by-products

Power generation and wastewater treatment using a novel SPEEK nanocomposite membrane in a dual chamber microbial fuel cell

In this paper, the performance of two common and two self-fabricated proton exchange membranes were compared. Nafion 112 and Nafion 117, which are two of the most common proton exchange membranes that can be used in all fuel cell systems, were compared to SPEEK and SP/CC/TAP. The results showed that at lower COD such as 2000 mg/l, Nafion 117 has the highest performance in terms of power production and COD removal, while once the COD of wastewater goes up to 5000 mg/l, SP/CC/TAP has approximately the same performance as Nafion 117. The membranes were characterized by FESEM, while the degree of sulfonation was measured by NMR. The oxidation activity of microorganisms was measure by cyclic voltammetry (CV). Also, the attachment of bacteria onto the anode electrode was observed by SEM, which showed that different bacteria from the media with a mixed culture inoculum had attached to the anode electrode

Power generation and wastewater treatment using a novel SPEEK nanocomposite membrane in a dual chamber microbial fuel cell

In this paper, the performance of two common and two self-fabricated proton exchange membranes were compared. Nafion 112 and Nafion 117, which are two of the most common proton exchange membranes that can be used in all fuel cell systems, were compared to SPEEK and SP/CC/TAP. The results showed that at lower COD such as 2000 mg/l, Nafion 117 has the highest performance in terms of power production and COD removal, while once the COD of wastewater goes up to 5000 mg/l, SP/CC/TAP has approximately the same performance as Nafion 117. The membranes were characterized by FESEM, while the degree of sulfonation was measured by NMR. The oxidation activity of microorganisms was measure by cyclic voltammetry (CV). Also, the attachment of bacteria onto the anode electrode was observed by SEM, which showed that different bacteria from the media with a mixed culture inoculum had attached to the anode electrode

Enhancing the desalination performance of forward osmosis membrane through the incorporation of green nanocrystalline cellulose and halloysite dual nanofillers

BACKGROUND: Membrane fouling remains an unmet challenge for all membrane processes, including osmotically driven forward osmosis (FO). Membrane modification is a straightforward and feasible approach to enhancing fouling resistance. In this study, thin film nanocomposite (TFN) membranes incorporated with dual nanofiller were prepared. Halloysite nanotube (HNT) was incorporated into the polysulfone substrate while functionalized nanocrystalline cellulose (NCC) was embedded within the polyamide (PA) thin layer of the TFN. RESULTS: The formation of crystalline needle-like NCC was observed through X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images. TFNs embedded with functionalized NCC at different loadings were characterized in terms of morphology, surface roughness and hydrophilicity, separation performance and antifouling propensity. The incorporation of hydrophilic NCC has significantly reduced the water contact angle from 69° for the TFN0.0 to 45° for TFN incorporated with 0.1 wt/v% of NCC. The water flux of TFN0.05, as the best performing membrane, was recorded as 21.34 L/m2 h. This was about 140% greater than that of TFN0.0 at the same operating conditions. The embedment of NCC also reduced the extent of concentration polarization (CP) in TFN0.05, which resulted in better protein fouling resistance and lower water flux decline in comparison to neat membranes. CONCLUSIONS: Overall, the enhancement of both the water flux and antifouling properties of the membrane, without compromising the salt rejection when a low amount of NCC (<0.1 wt/v%) was incorporated into the thin PA layer, demonstrated the potential of dual nanofillers TFN for effective forward osmosis desalination application