Defi Yusti Faidah

Dr. Defi Yusti Faidah

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 February 2024 in IEEE Access
Verified
Journal Article
Open access
TPTafia Hasna Putri
Tafia Hasna Putri
RCRezzy Eko Caraka
Rezzy Eko Caraka
Toni ToharudinToni Toharudin
Toni Toharudin
YKYunho Kim
Yunho Kim
Rung-Ching ChenRung-Ching Chen
Rung-Ching Chen
Bens PardameanBens Pardamean
Bens Pardamean
Particulate matter forecasting is fundamental for early warning and controlling air pollution, especially PM 2.5 . The increase in this level of concentration will lead to a negative impact on public health. This study develops a hybrid model of CNN-LSTM and CONV-LSTM by combining a convolutional neural network (CNN) with an LSTM network to forecast PM 2.5 concentration for the next few hours in Kemayoran DKI Jakarta, which is known as a busy area. We discovered the advantages of CNN in effectively extracting features and LSTM in learning long-term historical data from PM 2.5 concentration time series data. The predictive model of CNN-LSTM is carried out in a different architecture where the CNN process is carried out first to become the input of LSTM. For CONV-LSTM, it is carried out in one architecture where the multiplication in the LSTM architecture is coupled with the convolution process. This research will explain how the method of developing hybrid CNN-LSTM and CONV-LSTM in predicting PM 2.5 concentrations. Based on metric evaluation, the two models are compared to find the best model. Both predictive models produce MAPE values that fall into the good enough category with values <20%. Results were obtained for CONV-LSTM with MAE worth 6.52, RMSE 8.55, and MAPE 16.39%. As a result, the CONV-LSTM model performs better than CNN-LSTM in nowcasting PM 2.5 .

27 April 2022 in The Scientific World Journal
Verified
Journal Article
Open access
PDF file
DFDefi Yusti Faidah
Defi Yusti Faidah
Heri KuswantoHeri Kuswanto
Heri Kuswanto
SSSutikno Sutikno
Sutikno Sutikno
Generating an accurate rainfall prediction is a challenging work due to the complexity of the climate system. Numerous efforts have been conducted to generate reliable prediction such as through ensemble forecasts, the North Multi-Model Ensemble (NMME). The performance of NMME globally has been investigated in many studies. However, its performance in a specific location has not been much validated. This paper investigates the performance of NMME to forecast rainfall in Surabaya, Indonesia. Our study showed that the rainfall prediction from NMME tends to be underdispersive, which thus requires a bias correction. We proposed a new bias correction method based on gamma regression to model the asymmetric pattern of rainfall distribution and further compared the results with the average ratio method and linear regression. This study showed that the NMME performance can be improved significantly after bias correction using the gamma regression method. This can be seen from the smaller RMSE and MAE values, as well as higher R2 values compared with the results from linear regression and average ratio methods. Gamma regression improved the R2 value by about 30 higher than raw data, and it is about 20 higher than the linear regression approach. This research showed that NMME can be used to improve the accuracy of rainfall forecast in Surabaya.

31 December 2023 in The Scientific World Journal
Verified
Journal Article
Open access
PDF file
GDGumgum Darmawan
Gumgum Darmawan
BHBudhi Handoko
Budhi Handoko
DFDefi Yusti Faidah
Defi Yusti Faidah
DIDian Islamiaty
Dian Islamiaty
Rainfall is one of the climatic factors that influence various human activities and affect decision making in daily life activities. High intensity of rainfall can turn into a threat and cause serious problems such as causing various natural disasters. Therefore, it is essential to conduct rainfall forecasting to anticipate and enable preventive actions and can be used as a decision consideration in increasing the productivity and mobility of human activities. The aim of this study is to compare rainfall accuracy between the Gregorian and the lunar calendars using the bidirectional long short-term memory (Bi-LSTM) machine learning model through the grid search approach. This method was used because it can capture patterns arising from the simultaneous effects of two asynchronous calendars, Gregorian and lunar, which were used in this study by finding the right parameters. Monthly rainfall data from Bogor City, Indonesia, were used from the period of 2001 to 2022. The results show that the MAPE of the lunar calendar is relatively smaller at 14.82% which indicates the better forecasting ability than the Gregorian calendar which is 35.12%.

4 April 2023 in PRIMER : Jurnal Ilmiah Multidisiplin
Verified
Journal Article
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ASAldi Anugerah Sitepu
Aldi Anugerah Sitepu
BTBertho Tantular
Bertho Tantular
GDGumgum Darmawan
Gumgum Darmawan
RPResa Pontoh
Resa Pontoh
DFDefi Yusti Faidah
Defi Yusti Faidah
Produk Domestik Bruto (PDB) memiliki peran yang sangat penting dalam untuk mengerti kondisi perekonomian negara. Penelitian ini bertujuan untuk memodelkan variabel PDB dengan mempertimbangkan variabel RTGS (Real Time Gross Settlement). Akan tetapi, data yang digunakan dalam penelitian ini tidak memenuhi asumsi stasioner. Metode yang digunakan pada penelitian ini adalah Vector Error Correction Model (VECM) yang merupakan salah satu model multivariat runtun waktu yang merupakan bentuk Vektor Autoregresive terestriksi dengan data yang tidak stasioner namun kombinasi liniernya memiliki kointegrasi. Hasil analisis model tersebut adalah terdapat kointegrasi antara PDB dan RTGS. Parameter model diestimasi dengan hasil estimasi jangka panjang RTGS signifikan sebesar -0,8828. Dari analisis kausalitas Granger terdapat hubungan satu arah PDB dengan RTGS. Akurasi model ditunjukkan oleh nilai MAPE sebesar 0,10%.

1 January 2024 in Communications in Mathematical Biology and Neuroscience
Verified
Journal Article
Open access
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DFDefi Yusti Faidah
Defi Yusti Faidah
AHAshilla Maula Hudzaifa
Ashilla Maula Hudzaifa
RPResa Septiani Pontoh
Resa Septiani Pontoh
Diarrhea remains one of the leading causes of childhood morbidity and mortality worldwide, especially in developing countries. Diarrhea is a digestive disorder characterized by the need to defecate more often than usual. Diarrhea remains a major problem of public health in Indonesia, with 40% of cases occurring in children under five years old. Bandung City is one of the largest cities in West Java Province with the sixth highest cases of diarrhea in West Java. The high number of diarrhea cases in Bandung City is a serious concern in public health efforts, especially among young children. The incidence of diarrhea in children under five in Bandung City in 2022 was recorded as high as 6376 cases. Therefore, this study aims to cluster sub-districts in Bandung City based on factors that influence diarrhea cases. Five factors are used, namely the prevalence of diarrhea in children under five years old, clean and healthy living behaviour, healthy latrine facilities, population density, and many baby less than 6 months old are exclusively breastfed . Based on the results of clustering with the Gaussian mixture model, 5 regional groups were obtained based on similarity of characteristics with five factors. Cluster 2 are areas characterized by a high percentage of households with healthy latrines and healthy living behaviour. Cluster 5 are areas characterized by a high prevalence of diarrhea in children under five. The results of this clustering indicate the importance of interventions and strategies by the government of Bandung city to prevent the increasing number of diarrhea cases among children under five. Therefore, it can provide better insight into the distribution of diarrhea cases to achieve the Sustainable Development Goals (SDGs) and improve the health status of children under five in Indonesia, particularly in Bandung City.

11 October 2024 in BAREKENG: Jurnal Ilmu Matematika dan Terapan
Verified
Journal Article
Open access
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AHAshilla Maula Hudzaifa
Ashilla Maula Hudzaifa
VYValerie Vincent Yang
Valerie Vincent Yang
DFDefi Yusti Faidah
Defi Yusti Faidah
An analysis of the performance of Indonesia's capital market, or Indonesia Stock Exchange (IDX), shows significant growth in recent years, with market capitalization increasing dramatically from IDR 679.95 trillion in 2004 to IDR 11,674.06 trillion by 2023. The IDX plays an important role in the Indonesian economy by facilitating capital formation and providing opportunities for investors to diversify their portfolios. However, the capital market is vulnerable to political events, such as presidential elections, which can affect national stability and economic performance. An analysis of the stock index performance before the presidential election showed a significant bullish trend. Still, given the considerable impact of political events, such as presidential elections, on financial markets, this study aims to analyze and forecast the performance of the IDX Composite by examining historical data from past election years, we provide insights and predictions in highlighting how the LSTM model accommodates these political factors in its forecasts. IDX Composite closing price forecasting was conducted using the bidirectional LSTM model to anticipate the impact. The analysis results show that this model can predict the weekly closing price of the IDX Composite with an error of 1.04%, with estimated stock price fluctuations in the next 8 weeks in the range of 6619.755 to 6812.722