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INDONESIA
Indonesian Journal of Science and Technology
Published by Universitas Pendidikan Indonesia
ISSN : 25278045     EISSN : 25281410     DOI : -
Core Subject : Science, Social,
Computer Science & IT Environmental Science
Arjuna Subject : -
Articles 220 Documents
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A Review on Rotating Biological Contactors Waqas, Sharjeel; Bilad, Muhammad Roil
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18181

Abstract

Rotating biological contactors (RBC) is a wastewater treatment process that provides a both acceptable effluent quality and organic removal efficiency at a comparatively very low costs. It is highly attractive due to simplicity of operation, low sludge production, small foot-print, low maintenance, and low operational cost. Complete nitrification/denitrification can be achieved by varying the disk submergence level and operating the process under both anaerobic/anoxic conditions in a single unit. In this review, pros and cons of RBC are discussed in detail along with the factors affecting its performances. Organic and hydraulic loading and hydraulic retention time are the main parameters followed by additional parameters such as rotational speed, media, disk submergence, dissolved oxygen level, influent and effluent characteristics, and step-feeding in affecting the performance of an RBC system. RBC has shown promising results for the removal of biodegradable matter, nitrogen and phosphorous removal. The approaches for hybridization of biological processes to improve their overall performance are also review. Such success story is assess so explore possibility of developing RBC based hybrid processes. Hybrid RBC can be form from in-combination with other processes for minimizing energy requirements and maximizing the efficiency of the system.
Question Generator System of Sentence Completion in TOEFL Using NLP and K-Nearest Neighbor Riza, Lala Septem; Pertiwi, Anita Dyah; Rahman, Eka Fitrajaya; Munir, Munir; Abdullah, Cep Ubad
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18202

Abstract

Test of English as a Foreign Language (TOEFL) is one of learning evaluation forms that requires excellent quality of questions. Preparing TOEFL questions using a conventional way certainly spends a lot of time. Computer technology can be used to solve the problem. Therefore, this research was conducted in order to solve the problem of making TOEFL questions with sentence completion type. The built system consists of several stages: (1) input data collection from foreign media news sites with excellent English grammar quality; (2) preprocessing with Natural Language Processing (NLP); (3) Part of Speech (POS) tagging; (4) question feature extraction; (5) separation and selection of news sentences; (6) determination and value collection of seven features; (7) conversion of categorical data value; (8) target classification of blank position word with K-Nearest Neighbor (KNN); (9) heuristic determination of rules from human experts; and (10) options selection or distraction based on heuristic rules. After conducting the experiment on 10 news, it is obtained that 20 questions based on the results of the evaluation showed that the generated questions had a very good quality with percentage of 81.93% (after the assessment by the human expert), and 70% was the same blank position from the historical data of TOEFL questions. So, it can be concluded that the generated question has the following characteristics: the quality of the result follows the data training from the historical TOEFL questions, and the quality of the distraction is very good because it is derived from the heuristics of human experts.
High Unemployment Records of Graduated Students in the Development of Urban Agriculture in the Gaza Strip Al-Najar, Husam; Khalil, Hadi; Rahayu, Yuni Sri
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18176

Abstract

Urban agriculture plays a significant role in national development by contributing towards food security, job creation, and income generation. This study aims to assess the effect of unemployment records in graduated students in the recovery of the agricultural sector and the input to food security. A combination of both quantitative and qualitative research methods was employed in this study. In the quantitative design, 129 randomly selected urban farmers, completed the self-administered close-ended questionnaires, whereas the statistical analysis presents the socio-demographic, economic, and other aspects of the households. Based on the study result, around 2500 students graduated annually from 29 high educational institutes in Gaza Strip. The unemployment rate is around 41%, therefore the graduated students found that urban agriculture is contributing to create more jobs opportunities and improving household income. The analysis showed that 18% of the urban farmers are illiterate, 31% passed primary education, 25% passed secondary education, and 26% are holding university degrees in different fields. It is highly recommend to include urban agriculture in the future plans of the ministry of labours, ministry of agriculture, and all relevant institutions to overcome the high unemployment records and to alleviate poverty in Gaza.
Third Version of Weak Orlicz–Morrey Spaces and Its In-clusion Properties Masta, Al Azhary; Fatimah, Siti; Taqiyuddin, Muhammad
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18182

Abstract

Orlicz–Morrey spaces are generalizations of Orlicz spaces and Morrey spaces which were first introduced by Nakai. There are  three  versions  of  Orlicz–Morrey  spaces.  In  this  article,  we discussed  the  third  version  of  weak  Orlicz–Morrey  space, which is an enlargement of third version of (strong) Orlicz– Morrey space. Similar to its first version and second version, the third version of weak Orlicz-Morrey space is considered as  a  generalization  of  weak  Orlicz  spaces,  weak  Morrey spaces,  and  generalized  weak  Morrey  spaces.  This  study investigated  some  properties  of the third  version of weak Orlicz–Morrey spaces, especially the sufficient and necessary conditions for inclusion relations between two these spaces. One of the keys to get our result is to estimate the quasi- norm of characteristics function of open balls in ℝ.
Adaptive Mixed Finite Element Method for Elliptic Problems with Concentrated Source Terms Ilyas, Muhammad; Garnadi, Agah D.; Nurdiati, Sri
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18183

Abstract

An adaptive mixed finite element method using the Lagrange multiplier technique is used to solve elliptic problems with delta Dirac source terms. The problem arises in the use of Chow-Anderssen linear functional methodology to recover coefficients locally in parameter estimation of an elliptic equation from a point-wise measurement. In this article, we used a posterior error estimator based on averaging technique as refinement indicators to produce a cycle of mesh adaptation, which is experimentally shown to capture singularity phenomena. Our numerical results showed that the adaptive refinement process successfully refines elements around the center of the source terms. The results also showed that the global error estimation is better than uniform refinement process in terms of computation time.
A Design Model of Special Vocational High School for Children with Visual Impairment Maknun, Johar; Barliana, M Syaom; Cahyani, Diah
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18173

Abstract

This paper aimed to describe architectural design model of vocational high school that is accessible and meets the behavioral needs of children with visual impairment. The method used was a rational design method or often called as a glass box method, which was divided into four steps: 1) design criteria; 2) children with visual impairment’s behaviour; 3) programming; 4) designing model. The design criteria was combined based on its accessibility, space, sensory awareness, enhancement of learning, flexibility and ability, health and well-being condition, safety and security, sustainability, incorporation of nature environment and buildings, and availability of open space. These principle implemented from outside to inside the building, as well as from the site, landscape, building to interior of classroom. We believe that this study gives important for the need of architectural building model for students with special needs.
Nano Metal-Organic Framework Particles (i.e. MIL-100(Fe), HKUST-1(Cu), Cu-TPA, and MOF-5(Zn)) using a solvothermal process Nandiyanto, Asep Bayu Dani
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18178

Abstract

Metal-organic framework (MOF) is attractive because of its representation as a class of crystalline porous materials with excellent properties, specifically its chemical functionality and high porosity, making it potentially tailored for various desired applications. Although the synthesis of MOFs have been well-documented, most reports are in the bulk and micrometer sizes. The synthesis of MOFs in the smaller size is still inevitable. This work reports the synthesis of nano MOF particles (i.e., MIL-100(Fe), HKUST-1(Cu), Cu-TPA, and MOF-5(Zn)). In the experiment, MOFs were created by interacting ligands and metal ions in the specific solvent in the solvothermal process. Different from other reports, this study used low concentrations of ligands and metal ions, in which this is effective to control ligand-metal ion interaction, reaction, nucleation, and growth of MOF. The successful synthesis was obtained and effective for various MOF particles by changing types of ligands and metal ions. The study also obtained that compatibility and dilution of the ligands and the metal ions in the specific solvent are important parameters. This information will bring new strategies and further developments for the synthesis of MOF materials for wider range of potential applications in separation, catalysis, dye adsorption, and drug carrier uses.
Traceable Value for Proficiency Test of Natural Gas Ridwan, Yohanes Susanto; Supriadi, Supriadi; Nugraha, Willy Cahya
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18184

Abstract

The use of consensus values as the assign value for proficiency testing (PT) activities are currently a common practice in Indonesia, including the field of natural gas analysis. Hence, mostly the performance evaluation is based on consensus agreement. In this work, a PT was conducted using traceable values with respect  to ISO/IEC 17043 and ISO 13528. It was demonstrated that the chosen PT scheme has good capability to evaluate the performance of participating laboratories. And, in some cases, the selected PT scheme was not affected by extreme values and limited number of participants. Post analysis to the PT round has been conducted using the information of uncertainty of the traceable value and the uncertainty of robust average of participants’ results. It was demonstrated that there were no significance biases in the PT round. Moreover, it could be concluded that the participating laboratories have a good agreement with one to another. They also have a good agreement with traceable values, giving more additional confidence to the measurement quality in this field of analysis.
Investigation of the Adequacy of Bridge Design Loads in Pakistan Shahid, I; Noman, A. K.; Farooq, S. H.; Arshad, Ali
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18174

Abstract

Weight, configuration, and volume of traffic vary from country to country. But, in developing countries like Pakistan, bridges are designed based on codes of developed countries. Hence, these bridges may not have desired safety level. In this study, safety levels of three sample bridges has been investigated in terms of structural reliability index.  Live load effects (shear and moments) in girders were determined using weigh-in-motion data (WIM) and were extrapolated to 75 years using non-parametric fit. Two live load models and two strengths, required by 1967 Pakistan Code of Practice for Highway Bridges (PHB Design-Case) and that required by the 2012 AASHTO LRFD Bridge Design Specifications (AASHTO Design-Case) were used in reliability analysis. It is found that actual trucks produce moment and shear in girders 11 to 45 percent higher than live load models of PHB and AASHTO design cases. Values of structural reliability indices vary from 1.25 to 2.50 and from 2.45 to 3.15 for PHB and AASHTO design cases, respectively, and are less than the target reliability index value of 3.50 used in the design codes as benchmark.  It is revealed after the research that bridges in Pakistan may not have desired safety level, and current live load models may not be the true representation of service-level truck traffic.
The Price Dynamics of Hand Sanitizers for COVID-19 in Indonesia: Exponential and Cobweb Forms Machmud, Amir; Minghat, Asnul Dahar Bin
Indonesian Journal of Science and Technology Vol 5, No 2 (2020): IJOST: VOLUME 5, ISSUE 2, 2020
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v5i2.24431

Abstract

This study aims to analyze the impact of the COVID-19 pandemic on changes in handsanitizer prices in Indonesia. This study is motivated by the increasing demand for handsanitizers which has had an impact on price ratings. The method used is an explanatory survey with an exponential form approach for the demand function and Linear Cobweb Form for the supply function. The structure of the hand sanitizer market is assumed to be a perfectly competitive market. The results of the study indicate that despite changes in prices, the numerical analysis shows that prices are stable. The entry and exit of companies in the market does not affect price stability. This finding implies that after the pandemic the prices of handsanitizers will return to normal, so producers and consumers must remain rational.

Page 8 of 22 | Total Record : 220

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