Mathematical Model and Design Optimization of Reduction Gear for Electric Agricultural Vehicle

Pandu Sandi Pratama,변재영,Eun-Suk Lee,Dimas Harris Sean Keefe,Ji-Ung Yang,정성원,최원식 한국산업융합학회 2019 한국산업융합학회 논문집 Vol.22 No.1

In electric agricultural machine the gearbox is used to increase torque and lower the output speed of the motor shaft. The gearbox consists of several shafts, helical gears and spur gears works in series. Optimization plays an important role in gear design as reducing the weight or volume of a gear set will increase its service life and improve the bearing capacity. In this paper the basic design parameters for gear like shaft diameter and face width are considered as the input variables. The bending stress and material volume is considered as the objective function. ANSYS was used to investigate the bending stress when the variable was changed. Artificial Neural Network (ANN) was used to obtain the mathematical model of the system based on the bending stress behaviour. The ANN was used since the output system is nonlinear. The Genetic Algorithm (GA) technique of optimization is used to obtain the optimized values of shaft diameter and face width on the pinion based on the ANN mathematical model and the results are compared as that obtained using the traditional method. The ANN and GA were performed using MATLAB. The simulation results were shown that the proposed algorithm was successfully calculated the value of shaft diameter and face width to obtain the minimal bending stress and material volume of the gearbox.

Mathematical Model and Design Optimization of Reduction Gear for Electric Agricultural Vehicle

Pratama, Pandu Sandi,Byun, Jae-Young,Lee, Eun-Suk,Keefe, Dimas Harris Sean,Yang, Ji-Ung,Chung, Song-Won,Choi, Won-Sik The Korean Society of Industry Convergence 2019 한국산업융합학회 논문집 Vol.22 No.1

In electric agricultural machine the gearbox is used to increase torque and lower the output speed of the motor shaft. The gearbox consists of several shafts, helical gears and spur gears works in series. Optimization plays an important role in gear design as reducing the weight or volume of a gear set will increase its service life and improve the bearing capacity. In this paper the basic design parameters for gear like shaft diameter and face width are considered as the input variables. The bending stress and material volume is considered as the objective function. ANSYS was used to investigate the bending stress when the variable was changed. Artificial Neural Network (ANN) was used to obtain the mathematical model of the system based on the bending stress behaviour. The ANN was used since the output system is nonlinear. The Genetic Algorithm (GA)　technique of optimization is used to obtain the optimized values of shaft diameter and face width on the pinion based on the ANN mathematical model and the results are compared as that obtained using the traditional method. The ANN and GA were performed using MATLAB. The simulation results were shown that the proposed algorithm was successfully calculated the value of shaft diameter and face width to obtain the minimal bending stress and material volume of the gearbox.

The Effect of Hyperparameter Choice on ReLU and SELU Activation Function

Pratama Kevin,Dae-Ki Kang 한국인터넷방송통신학회 2017 Journal of Advanced Smart Convergence Vol.6 No.4

The Convolutional Neural Network (CNN) has shown an excellent performance in computer vision task. Applications of CNN include image classification, object detection in images, autonomous driving, etc. This paper will evaluate the performance of CNN model with ReLU and SELU as activation function. The evaluation will be performed on four different choices of hyperparameter which are initialization method, network configuration, optimization technique, and regularization. We did experiment on each choice of hyperparameter and show how it influences the network convergence and test accuracy. In this experiment, we also discover performance improvement when using SELU as activation function over ReLU.

Online-Based Local Government Image Typology: A Case Study on Jakarta Provincial Government Official YouTube Videos

Pratama, Arif Budy World Association for Triple Helix and Future Stra 2017 Journal of Contemporary Eastern Asia Vol.16 No.1

The Jakarta Provincial Government utilizes the YouTube channel to interact with citizens and enhance transparency. The purpose of this study is to explore online perceptions of local government image perceived by online audiences through the YouTube platform. The concepts of organizational image and credibility in the political image are adapted to analyze online public perceptions on the Jakarta Provincial Government image. Using the video summarization approach on Three hundred and forty-six official YouTube videos, which were uploaded from 1 March 2016 to 31 May 2016, and content analysis of Eight thousand two hundred and thirty-seven comments, this study shows both political and bureaucratic image emerge concurrently in the Jakarta Provincial Government case. The typology model is proposed to describe and explain the four image variations that occurred in the case study. Practical recommendations are suggested to manage YouTube channel as one of the social media used in the local government context.

A Systematic Review of Randomized Controlled Trials of Antibiotic Use in Diabetic Foot Ulcer Infections: Focus on Clinical Cure

Pratama Vincent,Risni Hindun Wilda,Yunir Em,Sauriasari Rani 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.1

Background The use of antibiotics in diabetic foot ulcer infections (DFUI) is essential in reducing morbidity. Optimal administration of antibiotics can improve clinical outcomes and reduce the risk of antibiotic resistance. This study aims to review the efficacy, in terms of clinical cure, of various regimens and the duration of antibiotic administration in DFUI patients, based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The efficacy based on microbiological response is also reviewed as the secondary outcome. Materials and Methods We used three databases, namely PubMed, Scopus, and ScienceDirect, to search for randomized controlled trials (RCTs) in patients with DFUI who required antibiotics. Results A total of 16 studies were included in the systematic review. The study locations and bacterial patterns varied, with the most common pathogen being Staphylococcus aureus. Most studies did not demonstrate a significant difference in clinical cure and pathogen eradication, either in the comparison between systemic and topical antibiotics or in the duration of administration. Some studies had similar characteristics and were analyzed to conclude. These studies showed that ertapenem had comparable efficacy to piperacillin/tazobactam. Similar results were also conducted from studies of piperacillin-tazobactam+amoxicillin-clavulanic acid vs. moxifloxacin. Conclusion Most studies have heterogeneous characteristics, possibly due to differences in research location. Therefore, there is no strong evidence to recommend a specific antibiotic with the highest efficacy. However, since all included studies are RCTs, this review provides a good summary in considering antibiotic choices when treating DFUI patients. Background The use of antibiotics in diabetic foot ulcer infections (DFUI) is essential in reducing morbidity. Optimal administration of antibiotics can improve clinical outcomes and reduce the risk of antibiotic resistance. This study aims to review the efficacy, in terms of clinical cure, of various regimens and the duration of antibiotic administration in DFUI patients, based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The efficacy based on microbiological response is also reviewed as the secondary outcome. Materials and Methods We used three databases, namely PubMed, Scopus, and ScienceDirect, to search for randomized controlled trials (RCTs) in patients with DFUI who required antibiotics. Results A total of 16 studies were included in the systematic review. The study locations and bacterial patterns varied, with the most common pathogen being Staphylococcus aureus. Most studies did not demonstrate a significant difference in clinical cure and pathogen eradication, either in the comparison between systemic and topical antibiotics or in the duration of administration. Some studies had similar characteristics and were analyzed to conclude. These studies showed that ertapenem had comparable efficacy to piperacillin/tazobactam. Similar results were also conducted from studies of piperacillin-tazobactam+amoxicillin-clavulanic acid vs. moxifloxacin. Conclusion Most studies have heterogeneous characteristics, possibly due to differences in research location. Therefore, there is no strong evidence to recommend a specific antibiotic with the highest efficacy. However, since all included studies are RCTs, this review provides a good summary in considering antibiotic choices when treating DFUI patients.

Graphene Field Effect Transistor for The Detection of Creatinine

Pratama Bagas,Kwang Soup Song(송광섭) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.6

NUMERICAL STUDY ON THE OPTIMUM NOZZLE INLET ANGLE OF LONG RETRACTABLE TYPE SOOT BLOWER

Pratama H.A.,Moballa B.,Kusuma G.E.,H.C. Kang(강희찬) 한국전산유체공학회 2019 한국전산유체공학회 학술대회논문집 Vol.2019 No.10

Conversational implicature comprehension strategies used by English learners in Indonesia

Hendi Pratama,Fathur Rokhman,Sri Rejeki Urip 경희대학교 언어정보연구소 2019 언어연구 Vol.36 No.3

Comprehension of conversational implicature is relatively easy for native speakers. However, the same degree of ease does not apply to second language learners. This study aims to uncover the strategies of second language learners despite the difficulties they face. Eighteen respondents are invited to join think-aloud protocols (TAP sessions). During the TAP sessions, respondents are instructed to answer thirty written questions assessing conversational implicature and, at the same time, asked to narrate their thoughts out loud during the session. The responses during these sessions are recorded and transcribed. The data is then codified and analyzed using receptive strategy categorization developed by Vandergrift (1997). The results of the analysis lead to clues on how second language learners, in general, strategize to understand conversational implicature. This study also reveals the difference between strategies used by learners with high implicature scores and those used by learners with low implicature scores.

The Impact of Quality and Price on the Loyalty of Electronic Money Users: Empirical Evidence from Indonesia

PUTRA, Pratama,JAYADI, Riyanto,STEVEN, Ignatius Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The electronic money market in Indonesia continues to experience an increase in the number of users and volume of transactions. However, the electronic money market, especially server-based, in Indonesia is becoming concentrated into a few issuers. Electronic money issuers compete in price and promotion wars to gain new customers and maintain their existing ones. This paper presents an analysis of the orientation and factors that influence the loyalty in electronic money products. The research model variables in this study are adopted from the E-Service Quality and Marketing Mix categories. These variables are hypothesized to affect the perceived value and then customer loyalty. The research population consists of all Indonesians who use server-based electronic money, with a sample of 400 individuals. The results show that, in the E-Service Quality group, reliability, responsiveness, and security significantly affect perceived value, while the perceived price and perceived promotional benefits significantly affect perceived value in the Marketing Mix group. The perceived price has the highest effect on the perceived value and customer loyalty, while the perceived value has a significant effect on customer loyalty. Finally, it was found that the customer is more sensitive to the price than quality in using electronic money.

Operation of dry distillation process on the production of radionuclide ¹³¹I at Puspiptek area Serpong Indonesia, 2021 to 2022

Chaidir Pratama,Daya Agung Sarwono,Ahid Nurmanjaya,Abidin Abidin,Triyatna Fani,Moch Subechi,Endang Sarmini,Enny Lestari,Yanto Yanto,Kukuh Eka Prasetya,Maskur Maskur,Fernanto Rindiyantono,Indra Saptiam Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.4

¹³¹I is a fission product produced in a nuclear reactor by irradiating tellurium dioxide, with a half-life of 8.02 day. The most important and widely used method for making ¹³¹I is irradiation using a nuclear reactor and post-irradiation followed by dry distillation. The advantage of the dry distillation process is that the process and the equipment are relatively simple, namely TeO₂ (m.p. 750 ℃), which can withstand heating during reactor irradiation. Based on TeO₂ irradiation by neutron following the technique of dry distillation was explained for production of ¹³¹I on a large scale. A dry distillation followed the radioisotope production operation using the 30 MW GA Siwabessy nuclear reactor to meet national demand. TeO₂ targets are 25 and 50 g irradiated for 87-100 h. The resulting ¹³¹I activity is 20.29339-368.50335GBq. According to the requirements imposed on the radionuclide purity of the preparation, the contribution of ¹³¹I training in the resulting preparation was not less than 99.9 %