Penanganan Fitur Kontinyu dengan Feature Discretization Berbasis Expectation Maximization Clustering untuk Klasifikasi Spam Email Menggunakan Algoritma ID3

Pemanfaatan jaringan internet saat ini berkembang begitu pesatnya, salah satunya adalah pengiriman surat elektronik atau email. Akhir-akhir ini ramai diperbincangkan adanya spam email. Spam email adalah email yang tidak diminta dan tidak diinginkan dari orang asing yang dikirim dalam jumlah besar ke mailing list, biasanya beberapa dengan sifat komersial. Adanya spam ini mengurangi produktivitas karyawan karena harus meluangkan waktu untuk menghapus pesan spam. Untuk mengatasi permasalahan tersebut dibutuhkan sebuah filter email yang akan mendeteksi keberadaan spam sehingga tidak dimunculkan pada inbox mail. Banyak peneliti yang mencoba untuk membuat filter email dengan berbagai macam metode, tetapi belum ada yang menghasilkan akurasi maksimal. Pada penelitian ini akan dilakukan klasifikasi dengan menggunakan algoritma Decision Tree Iterative Dicotomizer 3 (ID3) karena ID3 merupakan algoritma yang paling banyak digunakan di pohon keputusan, terkenal dengan kecepatan tinggi dalam klasifikasi, kemampuan belajar yang kuat dan konstruksi mudah. Tetapi ID3 tidak dapat menangani fitur kontinyu sehingga proses klasifikasi tidak bisa dilakukan. Pada penelitian ini, feature discretization berbasis Expectation Maximization (EM) Clustering digunakan untuk merubah fitur kontinyu menjadi fitur diskrit, sehingga proses klasifikasi spam email bisa dilakukan. Hasil eksperimen menunjukkan ID3 dapat melakukan klasifikasi spam email dengan akurasi 91,96% jika menggunakan data training 90%. Terjadi peningkatan sebesar 28,05% dibandingkan dengan klasifikasi ID3 menggunakan binning

Cocoa Pod Husk Biochar Reduce Watering Frequency and Increase Cocoa Seedlings Growth

Biochar amount applied in the growing soil medium may decrease water use of cocoa seedling during dry season and hence may increase water use efficiency, thus a polybag experiment was carried out in the Glasshouse Agricultural Faculty, Halu Oleo University, Kendari, Southeast Sulawesi Indonesia in 2016to evaluate the effect of cocoa pod husk (CPH) biochar and watering frequencies on growth of cocoa seedlings.The experiment was arranged in a randomized block design with seven cacao pod husk (CPH) biochar levels (without CPH biochar, 3 g CPH biochar kg-1 soil, 6 g CPH biochar kg-1 soil, 9 g CPH biochar kg-1 soil, 12 g CPH biochar kg-1 soil, 15 g CPH biochar kg-1 soil dan 18 g CPH biochar kg-1 soil) and three watering frequencies ( every two days, every four days and every six days) in three replications. Results showed that CPH biochar and watering frequency significantly influenced soil moisture. The rate of CPH biochar amendment determined watering frequency and cocoa seedling growth rate. CPH biochar improved cocoa seedling growth and reduced watering frequency. Cocoa seedlings treated with 9 g CPH biochar kg-1 soil and 60 g CPH biochar kg-1 soil with every six days of WF increased WUE by 208.8% and 262.22%, respectively, compared to no biochar application

Evaluation of commercial soy sauce koji strains of Aspergillus oryzae for γ-aminobutyric acid (GABA) production

In this study, four selected commercial strains of Aspergillus oryzae were collected from soy sauce koji. These A. oryzae strains designated as NSK, NSZ, NSJ and NST shared similar morphological characteristics with the reference strain (A. oryzae FRR 1675) which confirmed them as A. oryzae species. They were further evaluated for their ability to produce γ-aminobutyric acid (GABA) by cultivating the spore suspension in a broth medium containing 0.4 % (w/v) of glutamic acid as a substrate for GABA production. The results showed that these strains were capable of producing GABA; however, the concentrations differed significantly (P < 0.05) among themselves. Based on the A. oryzae strains, highest GABA concentration was obtained from NSK (194 mg/L) followed by NSZ (63 mg/L), NSJ (51.53 mg/L) and NST (31.66 mg/L). Therefore, A. oryzae NSK was characterized and the sequence was found to be similar to A. oryzae and A. flavus with 99 % similarity. The evolutionary distance (K nuc) between sequences of identical fungal species was calculated and a phylogenetic tree prepared from the K nuc data showed that the isolate belonged to the A. oryzae species. This finding may allow the development of GABA-rich ingredients using A. oryzae NSK as a starter culture for soy sauce production

Social–environmental drivers inform strategic management of coral reefs in the Anthropocene

Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014–2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse

PENGARUH PEMBERIAN BERBAGAI DOSIS GLIOKOMPOS TERHADAP PERTUMBUHAN DAN PRODUKSI TANAMAN CABAI MERAH (Capsicum annuum L.)

The aim of the research was to study the effect of several glyochompost's dosages on the  growth  and  production of chilli.    The research was carried out in  Lamomea  Village, District Konda, Konawe, Southeast Sulawesi, from December 2012 to February 2013. This research was arranged on  completely randomized block design consisted of 4 treatments, i.e : without glyochompost (Go), glyochompost 30 g (G1), glyochompost 40 g (G2) and glyochompost 50 g (G3) per 20 kg soils. Analysis of variance (ANOVA) was used for statistical data analysis. Duncan's Multiple Range Test (DMRT) was applied to determine the significantly diferent among treatment with   95%   convidence level. The results of the research showed that : (1) glyochompost effectively influenced the plant hight, total productive branch, total numbers and chilli’s weight, (2) Applications of glyochompost 50 gr per 20 kg soils have given the best influence on growth and production of chilli plants. Key words: chilli, growth, glyochompost, plants, productio

Effects of tourism-derived sewage on coral reefs: Isotopic assessments identify effective bioindicators

Pulau Redang and Pulau Tioman have experienced huge tourism growth over the last two decades, but minimal sewage treatment may threaten the resilience of their coral reefs. This study uses stable isotope techniques to identify suitable bioindicators of sewage nutrients (δ15N) at these islands by measuring macroalgae (Lobophora spp.), gastropods (Drupella spp.), scleractinian coral (Acropora spp.), and leather coral (Sinularia spp.). At tourist hubs using seepage septic tank systems, enrichment of Acropora δ15N (Redang, +0.7‰) and Sinularia δ15N (Tioman, +0.4‰) compared to pristine background levels indicate enhanced sewage nutrient discharge. Carbon isotopes and survey data suggest that sedimentation did not confound these δ15N trends. Potential damaging effects of sewage discharge on the coral reef communities at both islands are highlighted by strong correlations between Acropora δ15N and regional variation in coral reef community structure, and exclusive occurrence of degraded reefs at regions of high sewage influence

Dealing with variability in ecological modelling: An analysis of a random non‐autonomous logistic population model

[EN] This paper presents a methodology to deal with the randomness associated to ecological modelling. Data variability makes it necessary to analyse the impact of random perturbations on the fitted model parameters. We conduct such analysis for the logistic growth model with a certain sigmoid functional form of the carrying capacity, which was proposed in the literature for the study of parasite growth during infection. We show how the probability distributions of the parameters are set via the maximum entropy principle. Then the random variable transformation method allows for computing the density function of the population.Spanish Ministerio de Economia y Competitividad, Grant/Award Number: PID2020-115270GB-I00; Agencia Estatal de InvestigacionCalatayud Gregori, J.; Cortés, J.; Dorini, FA.; Jornet Sanz, M. (2022). Dealing with variability in ecological modelling: An analysis of a random non-autonomous logistic population model. Mathematical Methods in the Applied Sciences. 45(6):3318-3333. https://doi.org/10.1002/mma.74583318333345