University of Indonesia
  • Depok, Jawa Barat, Indonesia
Recent publications
In this research, we propose an optimal choice for the non-negative constant in the Dai-Liao conjugate gradient formula based on the prominent Barzilai-Borwein approach by leveraging the nice features of the Frobenius matrix norm. The global convergence of the new modification is demonstrated using some basic assumptions. Numerical comparisons with similar algorithms show that the new approach is reliable in terms of the number of iterations, computing time, and function evaluations for unconstrained minimization, portfolio selection and image restoration problems.
Scattering of spin-0 and spin- 1 2 $\frac{1}{2}$ particles is formulated in momentum space based on basis states being not expanded in partial waves. No sequential calculations with increasing angular momentum are performed to reach physical convergence, which depends on the scattering energy and the interaction range. Both nonrelativistic and relativistic cases are described. We put forward for consideration the utilization of this approach. By taking some simple interaction models we show some advantages in calculations representing those of high energy scattering as well as those of scattering governed by long range interactions.
This article aims to present the development, construction, and evaluation of an alternative computed tomography dose index (CTDI) phantom. Epoxy resin was mixed with an iodine-based contrast agent to produce radiological characteristics resembling polymethyl methacrylate (PMMA) as a standard CTDI phantom. As a preliminary study, testing was carried out using computed tomography images (80 and 120 kVp) on 12 variations of epoxy-iodine resin mixtures to obtain relative electron density ( ρe ) values and effective atomic numbers ( Zeff ) of the samples. The alternative CTDI phantoms were then constructed with a resin-iodine mixture using iodine concentrations that yield on closest ρe and Zeff values to those of PMMA. The evaluation was carried out by comparing dose measurement results at various energies between the alternative phantom and the International Electrotechnical Commission-standard CTDI phantom. At a concentration of 0.46%, the epoxy resin has ρe and Zeff with a deviation against PMMA of 0.12% and 1.58%, respectively, so that composition was chosen for the alternative CTDI phantom construction. The average dose discrepancy values were 5% and 1%, respectively, for the head and body phantoms in the tested tube voltages of 80 kVp, 100 kVp, 120 kVp, and 135 kVp. The Student’s t -test result between the alternative and the standard phantoms also showed P < 0.05, indicating the comparability of the alternative CTDI phantom with the standard CTDI phantom.
Artabotrys hexapetalus (L.f.) Bhandari, Annonaceae, is one of Artabotrys species found in Asia, such as Sri Lanka, India, China, Malaysia, Indonesia, and other Southeast Asian countries. This plant is traditionally used as an herbal medicine. This research explored the potential of A. hexapetalus leaf and stem bark ethanol extract to treat type 2 diabetes by inhibiting the activity of α-glucosidase, including its relationship with the antioxidant activity, phenolic content, and flavonoid content. The analysis used α-glucosidase inhibition assay, 2,2-diphenyl-1-picrylhydrazyl free radical inhibition assay, ferric reducing antioxidant power assay, total phenolic content, total flavonoid content, liquid chromatography-tandem mass chromatography, and molecular docking analysis. Results showed that stem bark extract had a moderate α-glucosidase inhibitory activity with an IC50 value of 47.084 ppm. In contrast, the leaf extract had a weak α-glucosidase inhibitory activity with an IC50 value of 104.755 ppm. Random permutation in random forest simulation was used to predict the factors contributing to the α-glucosidase inhibition. For stem bark and leaf extracts, the α-glucosidase inhibition activity was predicted to be influenced by antioxidant activity and phenolic compounds. Comparisons between various analyses were shown to corroborate the random permutation results. Nevertheless, since the major identified active compound that likely played a role in α-glucosidase inhibition in stem bark was from terpene groups, it was predicted that some major compounds with high α-glucosidase inhibitory and antioxidant activities in stem bark were yet-to-be-identified.
Background Periodontitis is an oral disorder triggered by chronic inflammation, and a major cause of human tooth loss. Porphyromonas gingivalis is a prominent component in the etiology of chronic periodontitis which forms a bacterial “red complex” with Tannerella forsythia and Treponema denticola. P. gingivalis can invade the periodontal tissue and lower the host-defense mechanisms by deregulating immune and inflammatory responses. In parallel, Streptococcus sanguinis represents oral commensal bacteria that act as pioneers for bacterial colonization in biofilm formation. A plant of traditional medicine to inhibit bacterial growth is soursop (Annona muricata L.) that contains active chemical compounds, namely alkaloids, phenolics, flavonoids, and tannins. Aim The study aimed to determine the antibacterial effectiveness of soursop leaf extract on P. gingivalis and S. sanguinis, and to compare the effect of the extract to that of the positive control of 0.2% chlorhexidine. Methods Ethanol extract of soursop leaves was prepared at concentrations of 60, 50, 25, 12,5, 6,25, and 3,125 vol%. The antibacterial effectiveness of soursop leaf extract on P. gingivalis dan S. sanguinis is tested for Minimum Inhibitory Concentration and Minimum Bactericidal Concentration. Results The observed MIC values of soursop leaf extract on P. gingivalis and S. sanguinis were 25% and 12,5%, while the MBC values were 50% and 60% (vol), respectively. There were significant differences in the inhibitory concentration of soursop leaf extract and positive control by 0,2% chlorhexidine against both P. gingivalis and S. sanguinis in post-hoc Tukey test (p ≤ 0.05). Conclusion Ethanol extract of soursop leaves can effectively inhibit and kill P. gingivalis and S. sanguinis in vitro.
Caries is the most prevalent disease in the world, and in Indonesia its prevalence is 88.8%. While the causative microbial agent of caries is Streptococcus mutans, Streptococcus sanguinis is a primary colonizer related to the formation of oral biofilms. Due to concerns on cost, access and side effects of the commercial solutions, many people still depend on plant-based medicinal alternatives. Plectranthus amboinicus (Lour.) Spreng is such a medicinal plant containing carvacrol and thymol that are known to have antibacterial effects. Aim: To determine the effectiveness of P. amboinicus extract in inhibiting growth of and killing S. mutans and S. sanguinis. Methods: Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined to characterize the antibacterial properties of the ethanol extract of P. amboinicus from extract concentrations of 50%, 25%, 12.5%, 6.25 %, and 3.125% (vol) against the two bacterial species. Results: MIC and MBC levels of the ethanol extract of P. amboinicus against S. mutans were 3.125% and 50%, respectively. The corresponding MIC and MBC levels of the extract against S. sanguinis were respectively 6.25% and 25%l test showed a significant difference between each treatment (p <0.05). Conclusion: Ethanol extract of P. amboinicus can effectively inhibit growth of and kill S. mutans and S. sanguinis.
An analysis and evaluation has been carried out on each test parameter contained in the compliance test of 1016 stationary and 480 mobile radiography devices compiled by the Indonesian Nuclear Energy Regulatory Agency (Badan Pengawas Tenaga Nuklir, BAPETEN) from 2019 to 2020. The data were categorised and analysed based on the devices’ age to observe the correlation of performance with the age of the X-ray machine. In addition, the implementation level of the Automatic Exposure Control (AEC) system test of the stationary radiography X-ray modality is also reviewed. The results of the evaluation showed that 89.9% of the stationary radiography devices unconditionally pass the test, 5.2% are in the status of ‘conditional pass’ and 4.9% fail the test. On the other hand, 84.8% of mobile radiography devices unconditionally pass the test, 2.1% are in the status of ‘conditional pass’ and 13.1% fail the test. From the evaluation conducted, there is no observable correlation between the age of the modality and the results of the compliance test. Overall, only 9.2% of stationary radiography X-ray compliance test reports have included the AEC test since it is not a mandatory requirement of the national protocol.
We study neural data-to-text generation to generate a sentence to describe a target entity based on its attributes. Specifically, we address two problems of the encoder-decoder framework for data-to-text generation: i) how to encode a non-linear input (e.g., a set of attributes); and ii) how to order the attributes in the generated description. Existing studies focus on the encoding problem but do not address the ordering problem, i.e., they learn the content-planning implicitly. The other approaches focus on two-stage models but overlook the encoding problem. To address the two problems at once, we propose a model named TransCP to explicitly learn content-planning and integrate them into a description generation model in an end-to-end fashion. We propose a novel Transformer-based Pointer Network with gated residual attention and importance masking to learn a content-plan. To integrate the content-plan with a description generator, we propose a tracking mechanism to trace the extent to which the content-plan is exposed in the previous decoding time-step. This helps the description generator select the attributes to be mentioned in proper order. Experimental results show that our model consistently outperforms state-of-the-art baselines by up to $2\%$ and $3\%$ in terms of BLEU score on two real-world datasets.
Website pada PT. Sherindo Cargo sejak awal didirikan perusahaan hingga sampai saat tidak ada pembaharuan dari segi user interface serta user experience saat menggunakannya. Serta informasi yang disajikan pun juga sangat minim. Dengan memanfaatkan kemajuan teknologi dan informasi melalui teknologi internet, maka kekurangan pada website tersebut bisa diatasi dengan menyesuaikan kebutuhan klien dan jaman. Metode digunakan untuk perancangan desain UI/UX website PT. Sherindo Cargo adalah design thinking dimana metode ini terdiri dari beberapa tahapan dari emphatize, define, ideate, prototype, dan testing dengan usability testing yang digunakan system usability scale. Design thinking merupakan metode dengan pendekatan ke pengguna untuk mengetahui apa yang menjadi keinginan serta masalah yang dihadapi terhadap website ini. Setelah itu akan dianalisis keluhan responden untuk dijadikan sebuah ide atau solusi yang nantinya akan menjadi sebuah fitur di rancangan user interface di website yang terbaru serta memberikan user experience yang lebih baik. System usability scale akan digunakan usai melakukan tahap testing untuk mengetahui apakah rancangan tersebut diterima oleh klien atau tidak. Model perancangan ini berperan untuk memfasilitasi antara pengguna dengan perusahaan untuk memudahkan dalam bekerja di bidang ekspedisi.
The development of the coffee business as a small and medium enterprise (SME) shows positive things with the increasing number of coffee, which means an abundance of existing coffee grounds. There is a lack of research on entrepreneur perspectives on coffee waste management. This study aims to analyze the perspective of coffee shop entrepreneurs in managing coffee waste and converting waste into alternative energy for sustainable and environmentally friendly prospects. Respondents in this study were 201 coffee shop owners in Bekasi, Indonesia, who received questionnaires using the snowball sampling technique; for data analysis, the paper used PLS-SEM. This study found that the entrepreneur perspective significantly affects coffee waste management, encouraging the sustainability of coffee shops. The results of the R-Square analysis show that coffee shop owner awareness is strongly influenced by coffee waste management knowledge (93.6%); the attitude of coffee shop owners is influenced by coffee waste management knowledge and coffee shop owner awareness (92.5%); and the coffee waste management behavior is influenced by coffee shop owner awareness and attitude of coffee shop owners (97.8%). In addition, entrepreneurs’ excellent attitudes and awareness toward the potential of coffee grounds encourage them to carry out better waste management through sorting procedures to convert coffee grounds into alternative energy. AcknowledgmentThis study is funded by the Directorate of Research and Development, Universitas Indonesia, under Hibah PUTI 2022 (Grant No. NKB-1364/UN2.RST/HKP.05.00/2022).
In Indonesia's manufacturing industry, which employs the third-largest workforce in the country, employee engagement is a critical measure of labor's contribution. Despite the industry's importance, diversity management—a key driver of engagement—lags, with low representation of women and persons with disabilities and persistent ethnic and racial discrimination in a nation known for its multiculturalism. Additionally, ageism is prevalent, manifesting as discrimination across different age groups. This study investigates the influence of four principal dimensions of diversity management—ethnic, gender, disability, and age—on employee engagement within the sector. Conducted as a field study in a manufacturing industry in Cilegon with 218 participants, the research provides insightful findings. Notably, it identifies age diversity management as the sole dimension with a significant impact on employee engagement, while the other three—ethnic, gender, and disability diversity management—do not show a substantial effect.
We investigated the resistance genes, pilus islet, biofilm formation ability, and sequence types of multidrug-resistant Streptococcus pneumoniae (MDRSP) isolated from the healthy children below 5 years of age in Indonesia. In all, 104 archived MDRSP isolates from previous carriage study in Indonesia in 2016-2019 were screened for the presence of antibiotic resistance genes and the rrgC (pilus islet 1) and pitB (pilus islet 2) genes. Multilocus sequence typing and biofilm formation was determined by PCR-Sequencing and the ability of cells to adhere to the walls, respectively. Results have shown that the mefA, ermB, and tetM genes were found in 93%, 52%, and 100% of MDRSP isolates respectively. The insertion of arginine, proline, and Ile-100-Leu were the most common mutations in the folA and folP genes. Pilus islet 1 and type 2 were discovered in 93% and 82% of MDRSP isolates respectively. The MDRSP isolates showed no biofilm formation ability (64%), and five out of ten strains of MDRSP strains were ST1464. This finding can be used to provide further considerations in implementing and monitoring pneumococcal vaccination in Indonesia.
The study explores the implementation of a novel pedagogical approach, hybrid ethnoscience-project based learning (E-PjBL) integrated with virtual assistive technology (VAT), to cultivate CT skills among students in a basic physics course. The E-PjBL framework integrates relevant cultural contexts and real-world projects into the physics curriculum. The presence of VAT provides a visual learning experience regarding ethnoscience contexts while also serving as a means to explain physics concepts at a high level of abstraction. The findings of our experiments reveal that students exposed to this hybrid approach show significant improvement in their CT skills, such as analysis, inference, evaluation, and decision-making. This research contributes to the growing knowledge of effective pedagogies that support the development of CT skills in the context of physics.
Previous research, on the representation of women in the Indonesian parliament in the 2019 General Election, identifies two common strategies used by women legislative candidates to win. One is to draw on women's networks to mobilize support and the other is to rely on the dynastic power. This paper contributes to existing studies by exploring the vital role of women NGOs in supplying and preparing women's legislative candidates through a case study of the West Sumatra Provincial Parliament in the 2019 General Election. Qualitative research methods were used for this research, drawing on in-depth interviews with women legislative candidates of West Sumatra Provincial Parliament and women activists. This paper reveals that the rise of women candidates in West Sumatra was “prepared” (dikader) by women's NGOs, namely Koalisi Perempuan Indonesia of West Sumatra and Wanita Islam of West Sumatra. These women NGOs have played an important role in getting women elected by providing political training, consultation, moral support, and access to women's networks. Women NGOs' support for these women candidates arose from their long-term socio-political relationship. This research has also revealed that the women candidates exercised a great deal of agency in reaching the voters through these women's NGOs and networks.
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42,059 members
Jarnuzi Gunlazuardi
  • Department of Chemistry
Budi Budiawan
  • Chemistry Faculty of Science
Rika Tri Yunarti
  • Department of Chemistry
Murdani Abdullah
  • Department of Internal Medicine
Kampus UI Depok, 16424, Depok, Jawa Barat, Indonesia