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All Journal JURNAL HUTAN LESTARI Jurnal Pendidikan dan Pembelajaran Khatulistiwa (JPPK) Journal of Tropical Soils Emerging Science Journal
. Iskandar
Library & Information Science Program Interdiciplinary Islamic Studies, Graduated School of Islamic University Sunan Kalijaga Yogyakarta, Indonesia
Agriculture, Biological Sciences & Forestry Decision Sciences, Operations Research & Management Education Environmental Science Languange, Linguistic, Communication & Media Mathematics Other

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PENGGUNAAN REFUTATION TEXT BERBANTUAN ALAT PERAGA UNTUK MEREMEDIASI MISKONSEPSI TENTANG FLUIDA DINAMIS DI SMA Iskandar, .
Jurnal Pendidikan dan Pembelajaran Khatulistiwa Vol 6, No 7 (2017): Juli 2017
Publisher : Jurnal Pendidikan dan Pembelajaran Khatulistiwa

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Abstract This research aimed to know the effectiveness of using refutation text readings assisted simple props in remediating students’ misconceptions about fluid dynamics in Taruna Bumi Khatulistiwa Senior High School Kubu Raya. This research was a quasy experimental design with nonequivalent control group design.  The sample  was the students of class XI IPA 1 (N=33) as the experiment class 1 and XI IPA 2 (N=31) as the experiment class 2 were chosen by intact group. The instrument of data collecting used diagnostic test like multiple choices without reasons. The results showed that the percentage of students who misconception were 86.67% and 88.46% at pretest. There were declines in the number of students who misconception about 63.67% and 44.21%. Based on the Mann-Whitney U test, there was the significant difference of the number of students’ misconceptions between the class remediated Refutation text assisted using simple props and without using simple props ( -2.44; 0,05). Remediation effectiveness showed by DQM price about 63.67% and 44.21%. This research is expected can be the alternative to remediate students’ misconceptions especially in physics. Keywords: Remediation, Misconception, Refutation Text, Simple Props, Fluid Dynamics
KARAKTERISTIK HABITAT RAFFLESIA (Rafflesia tuan-mudae) DI GUNUNG POTENG CAGAR ALAM RAYA PASI KALIMANTAN BARAT Erlinda, Asteria; Iskandar, .; Widiastuti, Tri
JURNAL HUTAN LESTARI Vol 6, No 4 (2018): JURNAL HUTAN LESTARI
Publisher : Universitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/jhl.v6i4.28890

Abstract

One of the plants endemic of West Kalimantan is Rafflesia Tuan-mudae. R. Tuan-mudae found at the Raya Pasi Nature Reserves in West Kalimantan, especially at Mount Poteng. Information about the habitat of R. Tuan-mudae at Mount Poteng is still not found. The purpose of this study was to get information about characteristics of habitat R. Tuan-mudae at Gunung Poteng Raya Pasi Nature Reserve. Data collection was carried out in May 2018, R. Tuan-mudae habitat analysis was carried out using a survey method. Data retrieval using observer plots was determined by purposive sampling technique. Using a double observation plot measuring 20 x 50 m, totaling 4 plots. The results of the study found 145 R. Tuan-mudae individuals, at an altitude between 431-503 masl, slope 18.25%, temperature 25 ° C-26.1 ° C with humidity between 83% -89%. This Rafflesia lives in the host plant Tetrastigma sp.Keywords: characteristics, habitat, Rafflesia Tuan-mudae
Comparative Analysis of ARIMA, Prophet, and Glmnet for Long Term Evolution (LTE) Base Station Traffic Forecasting Juhana, Tutun; Yuliana, Hajiar; Hendrawan, .; Iskandar, .; Musashi, Yasuo
Emerging Science Journal Vol 8, No 6 (2024): December
Publisher : Ital Publication

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/ESJ-2024-08-06-04

Abstract

This study evaluates the performance of three forecasting models—ARIMA, Prophet, and Glmnet—with the primary objective of equipping the telecommunication industry with effective tools for cellular traffic forecasting. These tools lay the foundation for efficient resource management, cost optimization, and enhanced service delivery. The study begins with dataset description and preparation, followed by the selection of traffic forecasting models, and concludes with performance evaluation based on metrics such as Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), Symmetric Mean Absolute Percentage Error (SMAPE), Root Mean Squared Error (RMSE), and Coefficient of Determination (R²). The main contribution of this research is a comprehensive comparison of the three forecasting methods, aiding practitioners and researchers in identifying the best prediction model for specific contexts. The findings reveal that Glmnet consistently outperforms ARIMA and Prophet across all categories of traffic forecasting on the selected performance metrics. Its ability to handle complex data structures, manage multicollinearity, and deliver robust and accurate predictions makes it the preferred choice for forecasting cellular network traffic in the telecommunications domain. Doi: 10.28991/ESJ-2024-08-06-04 Full Text: PDF
NOMA Performance Improvement with Downlink Sectorization Vidyaningtyas, Hurianti; Iskandar, .; Hendrawan, .; Pramudita, Aloysius A.
Emerging Science Journal Vol 9, No 1 (2025): February
Publisher : Ital Publication

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/ESJ-2025-09-01-017

Abstract

This study tackles the growing challenge of inter-user interference in Non-Orthogonal Multiple Access (NOMA) systems, particularly as user density increases in modern communication networks. The primary objective is to improve system performance by implementing a downlink sectorization strategy, which groups users into distinct sectors to manage interference and optimize resource allocation. A Sequential Power Allocation (SePA) algorithm was introduced to enhance power distribution within sectors, aiming to maximize both user capacity and overall sum rate. The methods employed included detailed simulations comparing the performance of traditional NOMA systems and those incorporating sectorization. The results demonstrate that sectorization can significantly boost the system’s sum rate by up to 25% and reduce decoding errors by as much as 51%, particularly when the number of users per sector is kept under 20. However, performance saturation occurs beyond this threshold, where additional users do not contribute to further improvements. The novelty of this research lies in applying spatial sectorization to NOMA, showing that spatial sectorization can minimize intra-sector interference, improve power efficiency, and maintain reliable communication in high-demand environments such as the Internet of Things (IoT). This study provides valuable insights for optimizing NOMA systems, crucial for next-generation wireless networks. Doi: 10.28991/ESJ-2025-09-01-017 Full Text: PDF
Utilizing Coal Ash and Humic Substances as Soil Ameliorant on Reclaimed Post-Mining Land Oklima, Ade Mariyam; Sudarsono, .; Iskandar, .; Suryaningtyas, Dyah Tjahyandari
JOURNAL OF TROPICAL SOILS Vol. 19 No. 3: September 2014
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2014.v19i3.161-169

Abstract

Coal ash and humic substances can be used as soil ameliorant in the reclamation of formerly mined land. Due to its high pH and nutrients content, coal ash can be used to improve the chemical properties of the soil, such as increasing of pH, and increasing the levels of nutrients availability in the soil. Humic substances may also be used to complement, as they can increase the release of nutrients from the coal ash. Thus, the objective of this study was to assess the influence of coal ash and humic substances on soil chemical characteristics, nutrient absorption, and plant growth. This study was conducted in two locations - in a nursery area, involving two treatment factors: coal ash at different dosages (0, 200, and 400 g polybag-1), and humic material also at varying dosages (0, 0.04, and 0.08 g C polybag-1); and in a post-mining field using similar treatments: coal ash dosage (0, 2.5, and 5.0 kg planting-1 hole) and humic material dosage (0, 0.56, and 1.12 g C planting hole-1). The results showed that coal ash and humic materials significantly increased the soil pH, available P, and exchangeable K, Ca and Mg. Coal ash also contained a number of heavy metals but in quantities that are far below the limits set by both Indonesian Government Regulation and the US Environmental Protection Agency (USEPA). The above soil amelioration effects mean that. applicaton of coal ash and humic substances can significantly increase the growth of Jabon trees in the reclaimed post-mining land.[How to Cite: Ade MO, Sudarsono, Iskandar and DT Suryaningtyas. 2014. Utilizing Coal Ash and Humic Substances as Soil Ameliorant on Reclaimed Post-Mining Land. J Trop Soils 19: 161-169. Doi: 10.5400/jts.2014.19.3.161] [Permalink/DOI: www.dx.doi.org/10.5400/jts.2014.19.3.161]
Characteristics of Heavy Metals Adsorption Cu, Pb and Cd Using Synthetics Zeolite Zsm-5 Priyadi, .; Iskandar, .; Suwardi, .; Mukti, Rino Rakhmata
JOURNAL OF TROPICAL SOILS Vol. 20 No. 2: May 2015
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2015.v20i2.77-83

Abstract

It is generally known that zeolite has potential for heavy metal adsorption. The objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested that the adsorption capacity was affected by the pore size of zeolite, negative charge of zeolite, diameter of hydrated and electronegative ion.
Characteristic and Genesis of Black and Red Soil Vertisol in Jeneponto Regency Juita, Nirmala; Iskandar, .; Sudarsono, .
JOURNAL OF TROPICAL SOILS Vol. 21 No. 2: May 2016
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2016.v21i2.123-128

Abstract

One of factors that is interasting from Vertisol to be investigated beside the management of the soil fertility was color variations which can vary from gray to brown and brownish red. Exclusive characteristics of Vertisol are shrink swell capacity with clay dominant clay that make agricultural activities in the Jeneponto area less productive. The purpose of this study was to assess the differences of physical and chemical characteristics of black and red Vertisol in Jeneponto R.egency. The research location was based on the difference and overlaying of soil color. Black soils were taken from the village Bontomarannu and Tonrokassi Timur while red soil and overlaying colors of red and black soil were taken from the village Sarroanging. Results showed that one of the chemical characteristic which was very differences between black and red soils were calcium carbonate and base saturation. Generally CaCO3 on black soil was higher (ranged of 13.20-36.73%) than red soil (ranged of 2.21-13.86%). As for overlaying colors of red and black soil were ranged of 2.62-3.88%. The highest base saturation was found in the black soil that was> 100%, red soil between 40-89% and overlaying colors red and black soil between 80-83%. While Fe, Mn and Al concentrations were highest with citrate dithionite bicarbonate extracts followed by oxalate and pyrophosphate extracts. Clay montmorillonite minerals were present in all profiles observed.
Co-Authors . Hendrawan . Suwardi Ade Mariyam Oklima Ade Mariyam Oklima Dyah Tjahyandari Suryaningtyas Erlinda, Asteria Hurianti Vidyaningtyas Juita, Nirmala Mukti, Rino Rakhmata Musashi, Yasuo Pramudita, Aloysius A. Priyadi, . Sudarsono Tri Widiastuti TUTUN JUHANA Yuliana, Hajiar