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Air pollution is the entry or inclusion of living things, energy substances, and other components into the air. Moreover, Air pollution is the presence of one or several contaminants in the outside atmospheric air such as dust, foam, gas, fog, smoke or steam in large quantities with various properties and time intervals of the contaminants in the air resulting in disturbances to the lives of humans, plants or animals. One of the parameters measured in determining air quality is PM 2.5. However, PM 2.5 has a higher probability of being able to enter the lower respiratory tract because small particle diameters can potentially pass through the lower respiratory tract. In this paper, we will get two different insight. First, the probability of status change using Markov chain and second, forecasting by using VAR-NN-PSO. More details we classify by three classifications no risk (1-30), medium risk (30-48), and moderate (>49) in Pingtung and Chaozhou. This data is starting from January 2014 to May 2019 and it can be modeled with the Markov chain. At the same time, we perform Hybrid VAR-NN-PSO to forecast PM 2.5 in Pingtung and Chaozhou. In this optimization, the search for best solutions is carried out by a population consisting of several particles. Based on the results of the discussion, opportunities for the transition from monthly status change are obtained continuous stochastic time with a stationary probability distribution. Regarding the VAR-NN-PSO, we obtained the mean absolute percentage error (MAPE) 3.57% for PM 2.5 data in Pingtung and 4.87% for PM 2.5 data in Chaozhou, respectively. This model can be predicted to forecasting 180 days ahead. Besides, the population in PSO has generated randomly with the smallest value and the high value the accuracy.

The recognition of herbs and spices among young generation is still low. Based on research in SMK 9 Bandung, showed that there are 47% of students that did not recognize herbs and spices. The method that can be used to overcome this problem is automatic digital sorting of herbs and spices using Convolutional Neural Network (CNN) algorithm. In this study, there are 300 images of herbs and spices that will be classified into 3 categories. It’s ginseng, ginger and galangal. Data in each category is divided into two, training data and testing data with a ratio of 80%: 20%. CNN model used in classification of digital images of herbs and spices is a model with 2 convolutional layers, where the first convolutional layer has 10 filters and the second convolutional layer has 20 filters. Each filter has a kernel matrix with a size of 3x3. The filter size at the pooling layer is 3x3 and the number of neurons in the hidden layer is 10. The activation function at the convolutional layer and hidden layer is tanh, and the activation function at the output layer is softmax. In this model, the accuracy of training data is 0.9875 and the loss value is 0.0769. The accuracy of testing data is 0.85 and the loss value is 0.4773. Meanwhile, testing new data with 3 images for each category produces an accuracy of 88.89%. Keywords: image classification, herbs and spices, CNN.

Rainfall is a natural phenomenon that needs to be studied more deeply and interesting to be analyzed. It involves numbers of human activities such as aviation, agriculture, fisheries, and also disaster risk reduction. Moreover, the characteristics of rainfall data follows seasonality, fluctuation, not normally distributed and it makes traditional time series challenging to use. Therefore, neurocomputing model can be used as an alternative to extraction information from rainfall data and give high performance also accuracy. In this paper, we give short preview about SST Anomalies in Manado, Northern Sulawesi and at the same time comparing the performance of rainfall forecasting by using three types of neurocomputing methods such as Generalized Regression Neural Network (GRNN), Feed forward Neural Network (FFNN), and Localized Multi Kernel Support Vector Regression (LMKSVR). In a nutshell, all of neurocomputing methods give highly accurate forecasting as well as reach low MAPE FFNN 1.65%, GRNN 2.65% and LMKSVR 0.28%, respectively.

Regression analysis is a statistical analysis that aims to model the relationship between response variable with some predictor variables. Geographically Weighted Regression (GWR) is statistical method used for analyzed the spatial data in local form of regression. One of the problems in GWR is how to choose the significant variables. The number of predictor variables will allow the violation of assumptions about the absence of multicollinearity in the data. Therefore, this needs a method to reduce some of the predictor variables which not significant to the response variable. This paper will discuss how to select significant variables by stepwise method. This method is a combination of forward selection method and the backward elimination method.Keywords: Geographically Weighted Regression, Backward Elimination, Forward Selection,Stepwise Method PendahuluanSebuah data pengamatan bila melibatkan informasi koordinat lokasi pengambilan data disamping data mengenai peubah-peubah yang sedang diamati maka termasuk dalam kategori data spasial. Analisis terhadap data spasial memerlukan perhatian lebih dibandingkan dengan analisis data nonspasial, khususnya ketika menggunakan regresi. Salah satu hal yang harus mendapat perhatian pada penanganan data spasial adalah kemungkinan munculnya heterogenitas spasial [1] . Heterogenitas spasial muncul karena kondisi data di lokasi yang satu dengan lokasi yang lain tidak sama, baik dari segi geografis, keadaan sosial-budaya maupun hal-hal lain yang melatarbelakanginya. Salah satu dampak yang ditimbulkan dari munculnya heterogenitas spasial adalah parameter regresi bervariasi secara spasial atau disebut juga terjadi nonstasioneritas spasial pada parameter regresi.Pada regresi OLS (Ordinary Least Square) diasumsikan bahwa nilai duga parameter regresi akan tetap (konstan), artinya parameter regresi bernilai sama untuk setiap titik di dalam wilayah penelitian (parameter global). Bila terjadi heterogenitas spasial pada parameter regresi, maka informasi yang tidak dapat ditangani oleh metode regresi OLS akan ditampung sebagai galat. Bila kasus semacam itu terjadi, regresi OLS menjadi kurang mampu dalam menjelaskan fenomena data yang sebenarnya. Untuk mengantisipasi munculnya heterogenitas spasial pada parameter regresi, regresi OLS dikembangkan menjadi Geographically Weighted Regression (GWR). Pada GWR, parameter regresi diasumsikan bervariasi secara spasial. Melalui penggunaan GWR akan dapat diketahui variasi spasial dalam nilai duga parameter, sehingga interpretasi yang berbeda dan berharga dapat diperoleh untuk setiap titik lokasi yang diteliti.Banyaknya variabel prediktor memungkinkan akan terjadinya pelanggaran asumsi tentang tidak adanya multikolinieritas dalam data [4] . Oleh karena itu diperlukan suatu metode untuk mereduksi beberapa variabel yang tidak signifikan terhadap responnya. Salah satu metode yang dapat digunakan adalah metode stepwise GWR. Penelitian ini