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Preliminary Study on the Determination of Volcanic Tremor Epicenter Using Semblance Method (Case Study of Sakurajima Volcano) Ratri Andinisari; Sukir Maryanto; Ahmad Nadhir
Natural B, Journal of Health and Environmental Sciences Vol 2, No 2 (2013)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1878.07 KB) | DOI: 10.21776/ub.natural-b.2013.002.02.12

Abstract

Volcanic tremor is one of the most important volcanic activities due its strong connection to magma movement and impeding eruption. Therefore, the determination of volcanic tremor epicenter becomes very important. The absence of apparent P and S wave arrival of volcanic tremor is the main constraint of its epicenter determination. The use of semblance method is required because semblance method requires no information about P and S wave arrival in epicenter determination. A preliminary application of semblance method has been done to determine the epicenter of 100 s length volcanic tremor of Sakurajima volcano. In this research we use the recorded seismic signal from 5 different volcano observatories, which are KOM, KAB, HIK, ARI, and HAR. The recorded tremor signal is then analyzed by using semblance method. The analysis is carried out by calculated semblance coefficient in every 30 s moving window along the signal. The resulting semblance coefficient varied from 0,25 to 0,42. The epicenter of observed volcanic tremor is located in the north-east part of Minamidake crater by -18,66o to 54,10o of azimuth counted from the east, while the epicentral distance of the observed volcanic tremor varied from 608,28 to 948,68 m from Minamidake crater.
JITT with assessment for learning: Investigation and improvement of students understanding of kinematics concept Akhmad Jufriadi; Ratri Andinisari
Momentum: Physics Education Journal Vol 4 No 2 (2020)
Publisher : Universitas PGRI Kanjuruhan Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21067/mpej.v4i2.4669

Abstract

This study aims to investigate and explore students' understanding of the concept of Kinematics, particularly in the concepts of acceleration, velocity, distance and displacement. This research used a mixed-method approach with an embedded experimental design. The research was conducted by involving 21 students consisting of 7 men and 14 women. This research used reasoned multiple-choice questions and short interviews to determine the students' initial and final understanding. The results showed that, before the intervention was carried out, as much as 42.86% of students did not understand the concept of distance and displacement correctly, as much as 26.99% of students did not understand the concepts of instantaneous velocity and average speed, as much as 45.6% did not understand the concepts of position, velocity and acceleration and as much as 87.31% did not understand about the direction of velocity and acceleration. In addition, the results showed that the application of JITT with assessment for learning could significantly improve students' understanding of concepts, with N-gain = 0.56 and effect size = 2.38. This study explains the difficulties and general understanding of students on the concepts of distance and displacement, and the direction of object acceleration. In addition, the integration of assessment for learning to JITT is an option in the learning process to improve understanding of Kinematics concepts.
High impact on students’ understanding of atomics radius on crystals geometry concept through implementation of JITT with 3D animation Hena Dian Ayu; Akhmad Jufriadi; Ratri Andinisari
Momentum: Physics Education Journal Vol 5 No 2 (2021)
Publisher : Universitas PGRI Kanjuruhan Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21067/mpej.v5i2.5557

Abstract

This study was conducted to analyze the students 'initial and final understanding after the application of JITT with 3D animation, to identify students' responses and arguments, and to determine the impact of using JITT with 3D animation. This research involved 43 students of the 6th semester of the 2019-2020 academic year of the Physics Education study program of the Universitas PGRI Kanjuruhan Malang who took solid state physics course. Students' initial and final understanding was analyzed through responses and arguments presented during the pretest, while the impact of JITT application with 3D animation was analyzed based on the results of the pretest and posttest as well as student responses during the learning process expressed through short interviews and discussions. The qualitative and quantitative data generated from the mixed-method approach were analyzed simultaneously. The results show that the students understand that the atomic radius for all the different crystal lattices is the same, namely a/2. This was awakened by an early understanding of the general definition of the radius. However, after following the JITT stages with 3D animation, their understanding changed that the atomic radius of each crystal lattice is different in length. In addition, the results of statistical analysis showed that there was a very significant increase in the students' mastery of concepts from an average of 26.9 to 96.7. Meanwhile, the N-gain value is very high, namely 0.96 in the very effective category, which illustrates that JITT with 3D animation has had a high impact on students' understanding of atomic radius in the concept of crystal geometry.
Review: land, cloud, and climate change (in focus: Borneo) Jason Pajimola Punay; Ratri Andinisari
Journal of Infrastructure Planning and Engineering (JIPE) Vol. 1 No. 1 (2022)
Publisher : Master Program of Infrastructure and Environmental Engineering, Postgraduate Program, Warmadewa University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (381.463 KB) | DOI: 10.22225/jipe.1.1.2022.33-37

Abstract

This article discusses the salient findings of the Intergovernmental Panel on Climate Change Special Report on Climate Change and Land (2019). Local impacts of global warming in Borneo are discussed in terms of changes in temperature and precipitation. A drier and warmer climate is expected with the continued deforestation of Borneo. Changes in land surface characteristics of Borneo also affect the properties of cloud that forms over it. Deforested areas are generally associated with diffused clouds, small cloud particles, and thin and high clouds. Low vegetative areas are associated with a low evapotranspiration rate and low amount of latent heat release, which discourages the formation of convective clouds. The weak updraft associated with a non-convective cloud cannot support the formation of large cloud droplets. Moreover, the deforestation of primary forests of Borneo and replacing them with palm trees may cause larger cloud properties’ variability over the area.
Vibration Modeling and Simulation of Braced and Unbraced Steel Structure Ratri Andinisari; Ester Priskasari; Vega Aditama; Bambang Wedyantaji; Rendy Adam Anggriawan
Journal of Infrastructure Planning and Engineering (JIPE) Vol. 2 No. 1 (2023)
Publisher : Master Program of Infrastructure and Environmental Engineering, Postgraduate Program, Warmadewa University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22225/jipe.2.1.2023.1-6

Abstract

Repeated dynamic loads on multiple stories structure may cause damage in the midst of natural disaster, such as earthquakes and landslides, hence it is necessary to observe how the response occurs. Therefore, this paper studies the performance of two-story steel frame without braces and with inverted V concentric braces. Both frames were given a static and a dynamic load in the form of a sinusoidal load for 2 seconds in the form of forced harmonic vibration. After the dynamic load is turned off, harmonic free vibration applies. Vibration is given to the weakest orthogonal axis on the frame with a frequency of 0,5 Hz; 1,03 Hz; 1.7 Hz. To reduce the deviation between stories that occur due to dynamic loads, bracing is provided as a stiffening element. The test variations are called models 1, 2 and 3 with model 1 unbraced frame and model 2 braced frame with the same load between floors, while model 3 unbraced frame model with weight 2nd floor is 3 times larger than 1st floor. It found that the braced frame has a minimum drift and its drift is enhanced with the increase of load capacity.
Analisis Bahaya Gempabumi di Wilayah Kabupaten Sumenep Berdasarkan Distribusi Seismisitas dan Nilai PGA Ratri Andinisari
Jurnal Teknik Sipil Info Manpro Vol 13 No 1 (2024): JURNAL INFOMANPRO
Publisher : Pascasarjana Teknik Sipil Institut Teknologi Nasional Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36040/infomanpro.v13i1.9861

Abstract

Korelasi antara distribusi seismisitas dan nilai PGA dapat digunakan untuk melakukan analisis bahaya bencana gempabumi pada suatu wilayah. Dalam kajian ini, kedua parameter tersebut digunakan untuk tingkat bahaya bencana gempabumi di Kabupaten Sumenep. Berdasarkan data seismisitas, terdapat sebanyak 257 gempabumi di wilayah Kabupaten Sumenep pada tahun 2010-2023. Terdapat pula gempabumi pada kategori sedang hingga tinggi pada tanggal 26 April 2018 dan 2 April 2019 dengan momen magnititudo 5,3 dan 4,9, masing-masing pada bagian perairan di selatan Pulau Raas dan Kangean. Kluster gempa bumi dengan magnitudo rendah juga ditemukan di pesisir selatan Pulau Raas dan Sapudi. Selain itu, rentang nilai PGA Kabupaten Sumenep adalah 0,1999 g hingga 0,2083 g dengan nilai tertinggi terdapat di wilayah Kabupaten Sumenep yang berbatasan dengan Kabupaten Pamekasan, serta di bagian selatan Pulau Sapudi dan Raas. Secara keseluruhan, Kabupaten Sumenep memiliki seismisitas dan nilai PGA yang rendah. Akan tetapi, adanya gempabumi dengan momen magnitudo sedang hingga tinggi memperkuat kemungkinan bahwa segmen-segmen patahan di kabupaten ini mampu menghasilkan gempabumi dengan momen magnitudo yang sama atau lebih besar di masa depan. Dengan demikian, dapat disimpulkan bahwa Kabupaten Sumepep terpapar bahaya gempabumi dengan level sedang.
EFFECTS OF ALUMINUM FIBERS ADDITIVE ON THE COMPRESSIVE STRENGTH OF A CONCRETE Sudirman Indra; Nadya Rachma; Mohammad Erfan; Endro Yuwono; Ratri Andinisari
Journal of Infrastructure Planning and Engineering (JIPE) Vol. 3 No. 1 (2024)
Publisher : Master Program of Infrastructure and Environmental Engineering, Postgraduate Program, Warmadewa University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22225/jipe.3.1.2024.1-4

Abstract

Utilizing recycled waste as an additional construction material is an innovation that can reduce the negative environmental impacts caused by waste. One of the wastes that can be utilized in this case is aluminum cans. The use of aluminum fiber in concrete mixtures is appropriate since aluminum is resistant to corrosion or rust. This research aims to determine the effect of adding aluminum fiber on the compressive strength of concrete. The aluminum cans were shaved into fibers with dimensions of 2 x 35 mm. The resulting aluminum fiber is then added into the concrete mixture with a percentage of 0%, 0.05%, 0.075%, 0.1%, and 0.125% of the total volume of the test objects. Tests for compressive strength was then carried out after test specimens were aged for 28 days. The test results showed a peak compressive strength of (20.72 ± 0.35) MPa is observed at the addition of 0.05% aluminum fiber relative to the volume of concrete used for testing. A regression analysis was performed based on the relationship between the amount of aluminum fiber additive and the resulting compressive strength. Based on this analysis, the optimum value for aluminum fiber to be added to the concrete is 0.040% of its volume.
Developing Digital Interactive Exploration of Historical Places with Blending BIM and Virtual Reality Suhari, Ketut Tomy; Purwanto, Hery; Andinisari, Ratri
The Indonesian Journal of Computer Science Vol. 13 No. 1 (2024): The Indonesian Journal of Computer Science (IJCS)
Publisher : AI Society & STMIK Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33022/ijcs.v13i1.3732

Abstract

The advancement of technology has opened new possibilities for exploring and experiencing historical places. This research aims to develop a digital interactive exploration platform that blends BIM and VR to provide an immersive and informative experience of historical sites. The study focuses on Candi Kidal, located in Kecamatan Tumpang, Kabupaten Malang, as the primary study area. The proposed method involves the integration of BIM and VR technologies to create a detailed and interactive virtual representation of Candi Kidal. The BIM models are the foundation for capturing and integrating various data sources. These models are then transformed into a VR environment, allowing users to explore the site virtually, interact with objects, and access relevant historical information. Data collection methods include site surveys, and historical research in the field. The BIM models are developed using software tools such as Autodesk Revit, while the VR environment is created using platforms like Unity3D. The development of the digital interactive exploration platform involves programming and scripting languages such as C#. The results demonstrate the effectiveness of developed platform in providing an immersive and informative experience for Candi Kidal. Users can navigate the virtual environment, view detailed architectural elements, and access historical information through interactive interfaces. The significance of this research lies in its potential to enhance the preservation, promotion, and accessibility of historical places. By blending BIM and VR technologies, the digital interactive exploration platform offers a unique and engaging experience that can attract a wider audience and foster a deeper understanding of cultural heritage.
TEMPORAL AND DEPTH VARIATION OF SEISMIC PARAMETERS PRIOR TO MAJOR EARTHQUAKES IN PALU REGION, INDONESIA Rahmalia, Diah Ayu; Andinisari, Ratri; Tampubolon, Danastri Lintang Pitaloka; Aminuddin, Jamrud; Yuliardi, Amir Yarkhasy; Fadhilah, Firda Haifa
JGE (Jurnal Geofisika Eksplorasi) Vol. 11 No. 3 (2025)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v11i3.498

Abstract

The Palu region in Central Sulawesi is high tectonic activity area due to a subduction zone and major fault system, which resulted in high seismic intensity. The b value, as the seismic characteristic, is a valuable parameter for evaluating stress conditions and earthquake precursors. This study aimed to investigate the temporal and depth variations of the b-value in the Palu region. We observed earthquake distribution over 75 years from 1950 to 2025, which was obtained from the United States Geological Survey catalog. We applied the declustering analysis to isolate the mainshock events by using the space-time window method. We also conducted the magnitude completeness estimation and b-value calculation with ZMAP. This result showed that the average b-value was around 0.88, which was indicated as an intermediate level of seismic activity, influenced by subduction and the Palu-Koro Fault. Decreasing b-value was observed prior to the 1996 and 2018 earthquakes, followed by an increase in the parameter. This pattern exhibited stress accumulation and release, which was represented by the magnitude distribution. This lowering characteristic of b-value could be a long term precursor to major earthquakes. Furthermore, the depth variation of b-value revealed high values in the upper crust (0–10 km), a decrease around 20–30 km, and a secondary increase near 40 km, which corresponds to the Moho, as indicated by shear wave velocity profiles. These results provide insight into the crustal structure and seismic behavior in a tectonically complex and tsunami-prone region.