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SIMULATION OF ANALYTICAL TRANSIENT WAVE DUE TO DOWNWARD BOTTOM THRUST Tjandra, Sugih Sudharma; Pudjaprasetya, Sri Redjeki; Wiryanto, Leo Hari
Journal of the Indonesian Mathematical Society Volume 21 Number 2 (October 2015)
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.21.2.189.93-104

Abstract

Generation process is an important part of understanding waves, especially tsunami. Large earthquake under the sea is one major cause of tsunamis. The sea surface deforms as a response from the sea bottom motion caused by the earthquake. Analytical description of surface wave generated by bottom motion can be obtained from the linearized dispersive model. For a bottom motion in the form of a downward motion, the result is expressed in terms of improper integral. Here, we focus on analyzing the convergence of this integral, and then the improper integral is approximated into a finite integral so that the integral can be evaluated numerically. Further, we simulate free surface elevation for three different type of bottom motions, classified as impulsive, intermediate, and slow  movements. We demonstrate that the wave propagating to the right, with a depression as the leading wave, followed with subsequent wave crests. This phenomena is often observed in most tsunami events.DOI : http://dx.doi.org/10.22342/jims.21.2.189.93-104
Penerapan Metoda Six Sigma DMAIC untuk Mengurangi Cacat Pakaian 514 (Studi Kasus di CV Jaya Reksa Manggala) Fransiscus, Hanky; Tjandra, Sugih Sudharma; Utama, Nixon Setia
Jurnal Rekayasa Sistem Industri Vol 7, No 1 (2018): Jurnal Rekayasa Sistem Industri
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (316.999 KB) | DOI: 10.26593/jrsi.v7i1.2716.31-40

Abstract

CV Jaya Reksa Manggala (JRM) is one of clothing company. With increasing competition in this clothing company, the companies are required to keep improving the quality of clothing products. One of the important things in quality is reduction of product defects. One of the proven methods of  quality improvement is the Six Sigma DMAIC method, which is a continous improvement method that aims to achieve the best quality. One of the products of CV JRM which is still have a lot of defects is 514 products. From the initial data obtained, DPMO value for process I and II for 514 products is 10,768.52 and 27,341.42 with sigma level 3.79 and 3.43. The steps undertaken in this Six Sigma DMAIC method include define, measure, analyze, implementation and control. Several proposed improvements were then made to reduce the problem of these defects and from the data at the control stage, the DPMO values of processes I and II became 2,941.76 and 1,812.69 with sigma levels of 4.25 and 4.41. From this result it can be said that with Six Sigma DMAIC method, there is improvement of quality for product 514 at CV JRM. 
Penerapan Metoda Six Sigma DMAIC untuk Mengurangi Cacat Pakaian 514 (Studi Kasus di CV Jaya Reksa Manggala) Sugih Sudharma Tjandra; Nixon Setia Utama; Hanky Fransiscus
Jurnal Rekayasa Sistem Industri Vol. 7 No. 1 (2018): Jurnal Rekayasa Sistem Industri
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (316.999 KB) | DOI: 10.26593/jrsi.v7i1.2716.31-40

Abstract

CV Jaya Reksa Manggala (JRM) is one of clothing company. With increasing competition in this clothing company, the companies are required to keep improving the quality of clothing products. One of the important things in quality is reduction of product defects. One of the proven methods of  quality improvement is the Six Sigma DMAIC method, which is a continous improvement method that aims to achieve the best quality. One of the products of CV JRM which is still have a lot of defects is 514 products. From the initial data obtained, DPMO value for process I and II for 514 products is 10,768.52 and 27,341.42 with sigma level 3.79 and 3.43. The steps undertaken in this Six Sigma DMAIC method include define, measure, analyze, implementation and control. Several proposed improvements were then made to reduce the problem of these defects and from the data at the control stage, the DPMO values of processes I and II became 2,941.76 and 1,812.69 with sigma levels of 4.25 and 4.41. From this result it can be said that with Six Sigma DMAIC method, there is improvement of quality for product 514 at CV JRM. 
Perancangan Alat Bantu Pemegang Glidecam Untuk Meminimasi Beban Pada Lengan Pengguna Sugih Sudharma Tjandra; Hanky Fransiscus; Farrelius Anthony Junior
Jurnal Rekayasa Sistem Industri Vol. 9 No. 1 (2020): Jurnal Rekayasa Sistem Industri
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1281.36 KB) | DOI: 10.26593/jrsi.v9i1.3618.45-54

Abstract

One of the tools used by cameramen to help stabilize while recording is Glidecam. Glidecam works based on the use of additional weights to compensate the load from the camera. However, there are still weaknesses in the use of Glidecam, including the fatigue and aches felt by the cameraman after Glidecam's use. In addition, it may cause disruption to joint, ligament, muscle, nerve and tendon function, and spine, for continuous Glidecam use. One alternative tool to overcome this problem is the use of Arm Brace. Arm Brace in the form of a passive exoskeleton that will compensate for part of the load from Glidecam. The product design process includes creating mission statements, identifying customer needs, determining product specifications, developing concepts, selecting concepts, making prototypes and evaluating prototypes. In this study two prototypes were made and evaluation with statistical tests showed that there was a significant increase in the endurance time of using Glidecam on the use of the two prototypes compared to that without the tools. The selection of the final prototype is done with a qualitative evaluation from the user. Qualitative evaluation is carried out with six assessment criteria: ease of use and installation, product mobility, product mass, product robustness, product support and product mechanism.Keywords: Glidecam, Arm Brace, Eksoskeleton 
Analisis Pertambahan Pasien COVID-19 di Indonesia Menggunakan Metode Rantai Markov Kinley Aritonang; Alfian Tan; Cherish Ricardo; Dedy Surjadi; Hanky Fransiscus; Loren Pratiwi; Marihot Nainggolan; Sugih Sudharma; Yani Herawati
Jurnal Rekayasa Sistem Industri Vol. 9 No. 2 (2020): Jurnal Rekayasa Sistem Industri (Edisi Khusus COVID-19)
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (292.726 KB) | DOI: 10.26593/jrsi.v9i2.3998.69-76

Abstract

COVID-19 is a new disease that is affecting almost all of the world. Until now there has not been a single drug (vaccine) that can be used to cure it. Many attempts were made to prevent the spread of this disease but COVID-19 patients are increasing every day, although at the same time some are recovering. This study will calculate the probability of additional patients occurring over a long period of time, referred as a steady state state condition, using the Markov chain method. Nine states have been formed to represent the daily increase ranges of COVID-19 patients number. The calculation results show that the possibility of additional patient number between 1 to 91, 92 to 182, 182 to 272, 273 to 363, 364 to 454, 455 to 545, 546 to 636, 637 to 727, or greater than 728 people a day are 0.21197, 0.05644, 0.08408, 0.16337, 0.13999, 0.14512, 0.07189, 0.07695, and 0.05014, respectively.
SIMULATION OF ANALYTICAL TRANSIENT WAVE DUE TO DOWNWARD BOTTOM THRUST Sugih Sudharma Tjandra; Sri Redjeki Pudjaprasetya; Leo Hari Wiryanto
Journal of the Indonesian Mathematical Society Volume 21 Number 2 (October 2015)
Publisher : IndoMS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22342/jims.21.2.189.93-104

Abstract

Generation process is an important part of understanding waves, especially tsunami. Large earthquake under the sea is one major cause of tsunamis. The sea surface deforms as a response from the sea bottom motion caused by the earthquake. Analytical description of surface wave generated by bottom motion can be obtained from the linearized dispersive model. For a bottom motion in the form of a downward motion, the result is expressed in terms of improper integral. Here, we focus on analyzing the convergence of this integral, and then the improper integral is approximated into a finite integral so that the integral can be evaluated numerically. Further, we simulate free surface elevation for three different type of bottom motions, classified as impulsive, intermediate, and slow  movements. We demonstrate that the wave propagating to the right, with a depression as the leading wave, followed with subsequent wave crests. This phenomena is often observed in most tsunami events.DOI : http://dx.doi.org/10.22342/jims.21.2.189.93-104
Perancangan Eksperimen Proses Ekstrusi Dengan Bahan Plastik Bekas Pakai Hanky Fransiscus, S.T., M.T.; Sugih Sudharma Tjandra; Monika Pangestu; Lusi Handranto
Jurnal Rekayasa Sistem Industri Vol. 11 No. 2 (2022): Jurnal Rekayasa Sistem Industri
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2877.796 KB) | DOI: 10.26593/jrsi.v11i2.5750.157-166

Abstract

Today, plastic waste is a serious problem and needs to be resolved immediately. Indonesia is the second largest contributor of plastic waste to the sea after China. This condition needs to be resolved  immediately by looking for alternative solutions for plastic waste in all areas of life, including plastic waste in educational institutions. Observations at the Parahyangan Catholic University (Unpar) show that 41% of the total inorganic waste come from plastic packaging bottles. One alternative solution to the plastic waste problem is  to recycle plastic waste and process it into other products that can be used. One alternative that is being explored for the process of recycling plastic waste in the Unpar environment is to use an extrusion machine in the Production Process Laboratory of the Faculty of Industrial Technology (FTI) Unpar. However, this machine has never been used for recycling plastic waste to be made into other products and the process parameters that can produce a good product are not yet known. Therefore, in this study, experimental design was carried out to determine process parameters to produce a good product with the existing extrusion machine. The plastic waste used in this test is plastic waste from Polypropylene (PP) plastic and Polyethylene Terephthalate (PET) plastic. The research consist of  determining factors, factor levels, and randomization of treatment using completely randomized design method. The response of this experimental test is the result of product quality assessment involving 3 experts. The results show that the extrusion process on PET plastic waste materials with existing machines has not produced good recycled products. Other processes and machine improvements are still needed to produce a good product. As for PP plastic waste material, the recycling results obtained are quite good. The ANOVA test results show that the barrel temperature will affect the value of the quality of the product produced from PP plastic waste.  
Application of Genetic Algorithms to Solve MTSP Problems with Priority (Case Study at the Jakarta Street Lighting Service) Sugih Sudharma Tjandra; Fran Setiawan; Hanoum Salsabila
Jurnal Optimasi Sistem Industri Vol. 21 No. 2 (2022): Published in November 2022
Publisher : The Industrial Engineering Department of Engineering Faculty at Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/josi.v21.n2.p75-86.2022

Abstract

Transportation is one thing that is very important and is the highest cost in the supply chain. One way to reduce these costs is to optimize vehicle routes. The Multiple Traveling Salesman Problem (MTSP) and Capacitated Vehicle Routing Problem (CVRP) are models that have been extensively researched to optimize vehicle routes. In its development based on actual events in the real world, some priorities must be visited first in optimizing vehicle routes. Several studies on MTSP and CVRP models have been conducted with exact solutions and algorithms. In a real case in the Jakarta City Street Lighting Section, the problem of determining the route in three shifts is a crucial problem that must be resolved to increase worker productivity to improve services. Services in MCB (Miniature Circuit Breaker) installation and maintenance activities for general street lights and priority is given to light points that require replacement. Because, in this case, the delivery capacity is not taken into account, the priority of the lights visited is random, and the number of street light points is enormous, in this study, we use the MTSP method with priority and solve by a genetic algorithm assisted by the nearest neighbor algorithm. From the resolution of this problem, it was found that the travel time reduction was 32 % for shift 1, 24 % for shift 2, and 23 % for shift 3. Of course, this time reduction will impact worker productivity so that MCB installation can be done faster for all lights and replace a dead lamp.
INTEGRATING MODIFIED LODGSERV WITH IMPROVEMENT GAP ANALYSIS TO DESIGN HOTEL SERVICE IMPROVEMENTS Alfi Safrianti; Sugih Sudharma Tjandra
International Journal of Economics, Business and Accounting Research (IJEBAR) Vol 6, No 3 (2022): IJEBAR, Vol. 6 Issue 3, September 2022
Publisher : LPPM ITB AAS INDONESIA (d.h STIE AAS Surakarta)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29040/ijebar.v6i3.6355

Abstract

The purpose of this study is to measure and analyze satisfaction of the Hotel X’s guests by its service quality. To achieve this, a modified LODGSERV scale is used as research instrument with total of 24 attributes used in questionnaire. In order to collect data, the questionnaire is distributed to guests who have stayed in Hotel X. The collected data is analyze using Improvement Gap Analysis to identify the highest priority level of the attributes that matter most to the hotel’s guest satisfaction. Based on the IGA matrix, there are 7 attributes that have the highest priority level for improvement. Furthermore, these attributes are identified by using fishbone diagram to obtain the root problem of each attribute. According to the root problems obtained, there are 15 suggestions for improvement are given to Hotel X.
Arduino-Based Development of Automatic Body Posture Measuring Device for Rapid Entire Body Assessment Method Halim, Lisa Keizia; Theopilus, Yansen; Tjandra, Sugih Sudharma
Jurnal Internasional Teknik, Teknologi dan Ilmu Pengetahuan Alam Vol 5 No 2 (2023): International Journal of Engineering, Technology and Natural Sciences
Publisher : Universitas Teknologi Yogyakarta, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46923/ijets.v5i2.221

Abstract

Workers from various industries can be exposed to musculoskeletal disorders (MSDs) risks in the workplace. Most cases of MSDs happen because of the accumulation of repetitive bad postures. Postural analysis can be done to implement changes that minimize MSDs risks in the workplace. The rapid entire body assessment (REBA) method provides an easy and fast measurement to analyze various postures. The accuracy of REBA assessments from observations is not good enough due to the limitations of human vision. The input of photo-based postural analysis also has a lot of error potential and takes up even more time. Therefore, this study aims to design a tool to do body posture measurements accurately and quickly. The Arduino-based postural analysis tool measures the position of several body segments, which are then used as the input of REBA in real time. The acceleration of each body segment recorded by the MPU6050 will be processed as displacement data and used to analyze the posture. The posture measurements detected by the tool is then used as input for REBA assessment. The device's accuracy was tested by comparing the photo-based postural analysis result to the postural analysis result of the tool. The reliability of the device was tested by Cronbach's Alpha method. The Cronbach's Alpha value of normal standing posture is 0.692, and the extreme posture's Cronbach's alpha value is 0.537. Multiple postures can be recorded at once using the tool. The tool can capture and assess multiple postures in approximately 6 minutes.