ITB Journal
Not a member yet
5999 research outputs found
Sort by
Applying Eco Enzyme to Reduce Chemical Oxygen Demand (COD) Content of Artificial River Water
No full textEco enzyme is claimed to improve the quality of polluted water. However, the low pH of eco enzyme solutions can acidify water. The objective of this study was to investigate the effectiveness of eco enzyme in reducing the COD of river water and its effect on the pH of sterilized synthetic river water. The effect of 0.01%, 0.5%, and 1% enzyme concentrations on the COD and pH of synthetic river water with an initial COD of 240 mg/l was investigated. The results showed that eco enzyme itself has high concentration of COD and low pH. The undiluted eco enzyme increased the COD and decreased the pH of both neutralized and non-neutralized synthetic river water. At a 1% eco enzyme concentration and neutral pH, the COD increased in the beginning of experiment and had decreased only by 31.7% after 6-8 days. The COD concentration in this steady state condition had a higher value than that of the initial COD concentration in the river water. This study showed that adding only eco enzyme to synthetic river water is not effective in reducing its COD content
Pixel Value Graphical Password Scheme: Analysis on Time Complexity performance of Clustering Algorithm for Passpix Segmentation
Get PDFPasspix is a key element in pixel value access control, containing a pixel value extracted from a digital image that users input to authenticate their username. However, it is unclear whether cloud storage settings apply compression to prevent deficiencies that would alter the file's 8-bit attribution and pixel value, causing user authentication failure. This study aims to determine the fastest clustering algorithm for faulty Passpix similarity classification, using a dataset of 1,000 objects. The source code for the K-Means, ISODATA, and K-Harmonic Mean scripts was loaded into a clustering experiment prototype compiled as Clustering.exe. The results demonstrate that the number of clusters affects the time taken to complete the clustering process, with the 20-cluster setting taking longer than the 10-cluster setting. The K-Harmonic Mean algorithm was the fastest, while K-Means performed moderately and ISODATA was the slowest of the three clustering algorithms. The results also indicate that the number of iterations did not affect the time taken to complete the clustering process. These findings provide a basis for future studies to increase the number of clusters for better accuracy
English
No full text
The prolonged period of the COVID-19 pandemic has unintentionally promoted a promising future for the e-learning industry. However, few studies have evaluated the acceptance of e-learning in non-school education, especially for young students. Using a modified technology acceptance model (TAM) as a theoretical framework, this case study investigates the influencing factors to determine the e-learning acceptance of young students in extracurricular education. The model was validated by empirical data collected from a mathematics tutoring center in Indonesia for primary and secondary students. While the literature suggests that young students tend to hold enjoyment as the most critical determinant toward their e-learning acceptance, this study shows the contrary result for extracurricular education, in which perceived usefulness becomes the most determining factor. The study also shows a substantial influence of subjective norms and system characteristics on students’ intentions to adopt or reject e-learning.Pandemi Covid-19 yang berkepanjangan secara tidak sengaja ikut mendukung masa depan cerah bagi industri e-learning. Namun, belum banyak penelitian yang mengevaluasi penerimaan e-learning pada pendidikan non-sekolah, terutama untuk siswa usia muda. Menggunakan modifikasi technology acceptance model (TAM) sebagai kerangka teori, penelitian ini menyelidiki faktor-faktor yang mempengaruhi penerimaan e-learning oleh siswa usia muda pada pendidikan ekstrakurikuler. Model tersebut divalidasi menggunakan data empiris yang didapatkan dari sebuah pusat bimbingan belajar matematika di Indonesia untuk siswa sekolah dasar dan menengah. Apabila literatur menunjukkan bahwa siswa usia muda cenderung menganggap kesenangan sebagai penentu utama dalam penerimaan e-learning mereka, penelitian ini menunjukkan hasil yang bertentangan untuk pendidikan ekstrakurikuler. Sebaliknya, persepsi manfaat menjadi faktor penentu utama. Penelitian ini juga menunjukkan pengaruh penting dari norma subjektif dan karakteristik sistem terhadap niat siswa untuk mengadopsi atau menolak sistem e-learning
A Subthreshold Biased CMOS Ring Oscillator Model Design in 180-nm Process
Get PDFIn this paper, a 180-nm CMOS ring oscillator design, made with halo-implanted transistors and operating in the weak inversion region, is proposed, based on an undergraduate integrated circuit design course methodology for building logic gates and comparing simulated results with reviewed literature data. Halo-implanted channel transistors have a steeper and less distorted voltage characteristic curve compared to uniformly doped channel ones, which makes them a more appropriate option when designing asynchronous digital integrated circuits aimed at low bias and low power. Three gate models were created using weak inversion and pull-up and pull-down networks made with halo-implanted transistors. The results of the study and simulation of the three inverter digital gate topologies showed that the NOT inverter model, as expected, had a higher frequency than the NAND and NOR inverter models. The ring oscillators made with the NOT inverter came up with an 8.25-MHz switching frequency as well as a dynamic power close to 270 nW. A comparison with other ring oscillators from previous studies is also shown
Enhanced Relative Comparison of Traditional Sorting Approaches towards Optimization of New Hybrid Two-in-One (OHTO) Novel Sorting Technique
Get PDFIn the world of computer technology, sorting is an operation on a data set that involves ordering it in an increasing or decreasing fashion according to some linear relationship among the data items. With the rise in the generation of big data, the concept of big numbers has come into existence. When the number of records to be sorted is limited to thousands, traditional sorting approaches can be used; in such cases, complexities in their execution time can be ignored. However, in the case of big data, where processing times for billions or trillions of records are very long, time complexity is very significant. Therefore, an optimized sorting technique with efficient time complexity is very much required. Hence, in this paper an optimized sorting technique is proposed, named Optimized Hybrid Two-in-One Novel Sorting Technique (OHTO, a mixed approach of the Insertion Sort technique and the Bubble Sort technique. The proposed sorting technique uses the procedure of both Bubble Sort and Insertion Sort, resulting in fewer comparisons, fewer data movements, fewer data insertions, and less time complexity for any given input data set compared to existing sorting techniques
Advancements, Challenges, and Future Directions in Rainfall-Induced Landslide Prediction: A Comprehensive Review
Get PDFRainfall-induced landslides threaten lives and properties globally. To address this, researchers have developed various methods and models that forecast the likelihood and behavior of rainfall-induced landslides. These methodologies and models can be broadly classified into three categories: empirical, physical-based, and machine-learning approaches. However, these methods have limitations in terms of data availability, accuracy, and applicability. This paper reviews the current state-of-the-art of rainfall-induced landslide prediction methods, focusing on the methods, models, and challenges involved. The novelty of this study lies in its comprehensive analysis of existing prediction techniques and the identification of their limitations. By synthesizing a vast body of research, it highlights emerging trends and advancements, providing a holistic perspective on the subject matter. The analysis points out that future research opportunities lie in interdisciplinary collaborations, advanced data integration, remote sensing, climate change impact analysis, numerical modeling, real-time monitoring, and machine learning improvements. In conclusion, the prediction of rainfall-induced landslides is a complex and multifaceted challenge, and no single approach is universally superior. Integrating different methods and leveraging emerging technologies offer the best way forward for improving accuracy and reliability in landslide prediction, ultimately enhancing our ability to manage and mitigate this geohazard
Structural Analysis and Service Life Prediction of Rubberized Thin Surfacing Hot Mix Asphalt
Get PDFRubberized thin surfacing hot mix asphalt (RTSHMA) is a type of flexible pavement that is currently being developed. It can provide the same good performance as asphalt concrete–wearing course (AC-WC). Based on previous research, the use of crumb rubber in the asphalt mixture can provide several advantages, such as increasing the flexibility of the mix so that the pavement is more resistant to cracking. Based on research showing the advantages of rubberized asphalt, the idea emerged to apply it in the field, namely on the Palur–Sragen City Boundary section as wearing course. The method of analysis in this study was modeling the pavement structure with the KENPAVE and BISAR 3.0 programs. The analysis results showed that the AC-WC model and RTSHMA model have the same good performance because both of them have a service life of more than twenty years, which is the standard for flexible pavements. However, RTSHMA has an advantage, i.e., the thickness layer is 25% thinner than AC-WC’s. With a thinner layer than AC-WC but the same good performance, RTSHMA is worth considering as an alternative pavement, especially for overlays
Inovasi Akar Rumput sebagai Proses Pemecahan Masalah : (Studi Kasus: perajin Bambu Selaawi dan perajin Sapu Ijuk Purwakarta)
No full textWest Java is well known for its abundant natural resources and handicrafts. Because of the abundant natural resources, many handicrafts are produced by local craftsmen. One of them is bamboo handicrafts in Selaawi, which are known for their bird cages, woven bamboo baskets, and so on. Another craft in West Java that still survives and has become the hallmark of the region is the palm-fiber broom in Purwakarta. During the production process, bamboo craftsmen in Selaawi and palm-fiber broom craftsmen in Purwakarta are known to have unique production tools that are specially made for certain functions. These simple tools are developed based on the special needs of production combined with the limited availability of tools and materials. Even though it is simple in shape, this equipment is an essential production tool that plays an important part in craftsman’s production activities. Nowadays, the challenge is the lack of motivation of the younger generation who work as artisans due to economic factors and a lack of knowledge about alternative solutions to achieve affordable and simple production. Through the digitizing artifacts method, the author archived various handicraft products and their production techniques from two case study areas in craft-centers, namely Selaawi and Purwakarta. Data collection and interviews resulted in the findings that the craftsman had gone through an innovation process using a social approach.Jawa Barat memiliki kekayaan sumber daya alam yang melimpah dan hasil kerajinan yang beragam dari berbagai daerah. Selain karena faktor sumber daya alamnya, keunikan produk kerajinan juga merupakan hasil dari buah pikir dan tenaga para perajinnya. Salah satunya adalah kerajinan bambu di Selaawi yang dikenal melalui produk sangkar burung, keranjang anyaman bambu dan sebagainya. Kerajinan lain di Jawa Barat yang juga masih bertahan dan menjadi ciri khas daerahnya adalah sentra sapu ijuk di Purwakarta. Dalam melakukan proses produksi, para perajin bambu di Selaawi dan perajin sapu ijuk di Purwakarta diketahui memiliki beberapa alat produksi yang dibuat sendiri khusus untuk fungsi tertentu. Peralatan sederhana tersebut dibuat berdasarkan kebutuhan khusus produksi serta ketersediaan alat dan material yang terbatas. Walaupun sederhana, peralatan tersebut merupakan senjata utama yang menjadi bagian penting dari aktivitas produksi para perajin. Tantangan yang saat ini terjadi adalah masih kurangnya motivasi generasi muda yang berprofesi sebagai perajin dikarenakan faktor ekonomi dan kurangnya pengetahuan mengenai berbagai alternatif alat produksi sederhana dan terjangkau. Melalui metode digitisasi artefak, penulis melakukan pengarsipan terhadap produk kerajinan dan teknik produksinya dari dua daerah studi kasus sentra kerajinan yaitu Selaawi dan Purwakarta. Pendataan dan wawancara menghasilkan temuan bahwa para perajin telah melalui proses inovasi dengan pendekatan sosial
Remappings of a Region: Popular Map Images Around and Beyond ‘Southeast Asia’
Get PDFOur spatial understandings and perceptions are augmented by media representations of spaces. Whilst maps are often studied within the academic fields of geography and art history, their discussion within the context of design and design history remains insufficient. This paper delves into the study of popular maps as cross-cultural design artefacts. This is done through case studies from the perspective of graphic communication, analyzing maps along their symbolic, narrative, and discursive interpretations as well as how they interplay with lived experiences. The period from 1930s to the 1960s saw several events that led to frequent remappings of geo-entities around the loose assemblage of nations that we now know as Southeast Asia, which included the birth of new nations and the forging of alliances. This process of repeated remappings enables an interesting study on the nature of maps, their instrumentalization, and their consumption