Garuda - Garba Rujukan Digital

APLIKASI RESPON PERMUKAAN DAN GOAL PROGRAMMING UNTUK OPTIMASI MORFOLOGI KOLAM LASAN PADA PENGELASAN INCONEL 625 Abdullah Shahab
Seminar Nasional Aplikasi Teknologi Informasi (SNATI) 2010
Publisher : Jurusan Teknik Informatika, Fakultas Teknologi Industri, Universitas Islam Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar

Introduksi panas pada pengelasan Tungsten Inert Gas (TIG) memicu terbentuknya kolam lasan denganmorfologi tertentu. Kedalaman atau penetrasi, dan rasio penetrasi dan lebar kolam lasan, atau rasio P/L,memegang peranan yang menentukan dalam keberhasilan proses pengelasan. Model matematik polinomial derajat dua dipostulasikan untuk menjelaskan kaitan antara penetrasi danrasio P/L dengan parameter pengelasan: arus, kecepatan pengelasan, dan sudut ketirusan elektrode. Denganmenggunakan data percobaan yang cukup banyak, model dengan ketepatan yang sangat baik berhasil diperolehdengan menggunakan metode respon permukaan. Harga parameter yang mampu menghasilkan penetrasi yang sudah ditentukan dengan rasio P/L yangmendekati target, dicari dengan menggunakan programa matematik goal programming. Parameter optimal inidijaga agar harganya tidak terlalu jauh dari harga parameter percobaan. Pengelasan yang dilakukan dengan parameter optimal yang diperoleh dari permodelan menunjukkan hasilyang diharapkan baik dari ketepatan penetrasi maupun harga rasio P/L yang mendekati target yang ditetapkan.Kata kunci :Pengelasan TIG, Morfologi Kolam Lasan, Respon Permukaan, Goal Programming.

Studi Eksperimental Pengaruh Model Sistem Saluran Dan Variasi Temperatur Tuang Terhadap Prosentase Porositas, Kekerasan Dan Harga Impact Pada Pengecoran Adc 12 Dengan Metode Lost Foam Casting Restu Yanuar Salam; Abdullah Shahab
Jurnal Teknik ITS Vol 4, No 1 (2015)
Publisher : Direktorat Riset dan Pengabdian Masyarakat (DRPM), ITS

Metode pengecoran lost foam merupakan metode yang tergolong baru dalam industri pengecoran logam. Pada saat ini belum banyak industri pengecoran logam yang menggunakan metode ini dalam memproduksi benda cor. Sedikitnya industri yang menerapkan metode pengecoran ini, yang mendorong untuk melakukan percobaan pengecoran dengan menggunakan metode lost foam, dengan melakukan perbedaan variasi temperatur tuang dan variasi model sistem saluran. Proses pengecoran dengan metode lost foam ini menggunakan styrofoam sebagai polanya, yang ditanam dalam cetakan yang berisi pasir silika kering (tanpa pengikat) kemudian cetakan digetarkan untuk memadatkan pasir. Ketika logam cair dimasukkan ke dalam cetakan, maka styrofoam akan menguap sampai cetakan tersebut terisi penuh oleh logam cair. Dalam penelitian ini, parameter yang digunakan adalah model sistem saluran dan variasi temperatur tuang terhadap kualitas hasil coran, diantaranya kekerasan, harga impact, prosentase porositas dan struktur mikro. Material yang digunakan dalam pengecoran ini adalah ADC (Aluminium Die Casting) 12. Parameter pertama yaitu model sistem saluran meliputi saluran samping, saluran bawah, saluran bawah dengan 2 gate dan saluran bawah dengan 3 gate dengan temperatur tuang konstan 700°C. Parameter kedua yaitu variasi perbedaan temperatur tuang antara 700°C, 750°C, 800°C dan 850°C dengan sistem saluran samping. Dari hasil penelitian ini diperoleh bahwa sistem saluran samping memiliki prosentase cacat porositas paling sedikit dibanding sistem saluran lainnya yaitu sebesar 2,7535% dan memiliki harga impact rata-rata paling besar yaitu 0,0275 J/mm2 pada potongan 1 dan 0,0660 J/mm2 pada potongan 2. Variasi temperatur tuang berpengaruh terhadap banyaknya cacat porositas dan harga impact rata-rata. Temperatur tuang 700°C dibanding temperatur tuang yang lain memiliki cacat porositas paling sedikit dan harga impact rata-rata paling besar yaitu 0,0275 J/mm2 pada potongan 1 dan 0,0660 J/mm2 pada potongan 2. Namun dari hasil pengujian kekerasan baik pada parameter model sistem saluran dan variasi temperatur tuang tidak dapat menunjukan perbedaan yang jelas.

APLIKASI PROGRAMA DINAMIS UNTUK OPTIMASI KEANDALAN SISTEM MPEG BOARD DAN POWER SUPPLY VCD PLAYER Jemmy Loarens; Abdullah Shahab
Jurnal Teknobisnis Vol 1, No 2 (2005): Jurnal TEKNOBISNIS
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat- Institut Teknologi Sepuluh Nopember

VCD Player consists of 3 electrical parts, MPEG Board, Loader Module, and Power Supply. These parts comprise several components, which could be procured from different suppliers, at a variable reliability and costs. A study was carried out to determine a choice and an optimal combination of these components to satisfy the reliability of the system and available budget. Optimization was performed using Deterministic Dynamic Programming method. The characteristically non-linear equation of the objective function of this problem made the Dynamic Programming (DP) a reasonable alternative. By assigning stages, states, decision variables, and pay-off, which characterized the feature of DP model, related to the choice and the cost of the components, optimization of the problem, which was done by stages, could be done. In this study, two versions of optimization were done: to optimize the reliability of the system constrained by the budget available, and to optimize the cost subjected to a determined reliability of the system. The results showed that optimization of system reliability using DP resulted in optimal system reliability in a constrained budget. The method used is also proven able to obtain a reliability of the system hitherto required, even with a relatively lower budget.

APLIKASI BINARY INTEGER PROGRAMMING PADA PENYELESAIAN MASALAH LINE BALANCING Gogor Arif Handiwibowo; Abdullah Shahab
Jurnal Teknobisnis Vol 2, No 1 (2006): Jurnal TEKNOBISNIS
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat- Institut Teknologi Sepuluh Nopember

The proper assignment of work activities in a number of workstations in a production line system influences heavily the success of the production process. This problem is hitherto solved by trial and error or using the heuristic method which naturally does not ensure an optimal solution. The method of Binary Integer Programming is here proposed to solve this problem, which will ultimately guarantee an optimal solution. Optimization is carried out by formulating mathematical model programming with an objective function compelled to achieve the minimum number of workstations. This optimization is performed under the constraints of interdependency between work activities, cycle time, activities time, demand, and productive time available. The model is then employed in the production of women slipper. Optimization carried out by suitable software is proven able to assign each work activity in a specific workstation with an optimal efficiency. Comparison with the current performance shows a substantial efficiency increase.

PERANCANGAN SISTEM DISTRIBUSI PUPUK MENGGUNAKAN NEURAL NETWORK DAN MIXED LINEAR PROGRAMMING Edi Surjono; Abdullah Shahab
Jurnal Teknobisnis Vol 1, No 1 (2005): Jurnal TEKNOBISNIS
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat- Institut Teknologi Sepuluh Nopember

Business environment is pushing a fertilizer distribution company, which is currently concentrating in Java, to expand their market to another area in Indonesia. Kalimantan is one of the target areas, and several provinces in Kalimantan are then chosen to be potential areas to be reached.To accommodate this need, it is necessary that an extensive distribution networks, involving ports, depots, warehouses, ships, and various land transportations, which is capable to fulfill the demand of each region with minimum cost, be considered. Optimization technique using Mixed Integer Programming is applied. The purpose of this optimization is to minimize transportation cost as well as other costs for building depots and warehouses, with a due consideration of technological and economical constraints.One of the most important data required for this optimization is the prediction of demand for each region. Neural Network is used for this purpose. Using some parameters identified as factors affecting fertilizer consumption in several areas in Java, demand forecasting of fertilizer for some areas in Kalimantan could be well predicted.By applying demand prediction excerpted from the output of Neural Network and optimization using Mixed Integer Programming, an optimal distribution system in Kalimantan could be procured. The result of the optimization will specify which ports, depots and warehouses, that should be built, as well as ships and land transportations that should be used, which accordingly will guarantee an optimal distribution system.

PROGRAMA MATEMATIS PENYELESAIAN MASALAH PROJECT CRASHING Irawati Irawati; Abdullah Shahab
Jurnal Teknobisnis Vol 2, No 1 (2006): Jurnal TEKNOBISNIS
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat- Institut Teknologi Sepuluh Nopember

The determination of project accomplishment time is tedious and time consuming. This problem is aggravated in a project with a plenty of activities exhibiting intricate interdependency among activities. The determination of project completion time, in general, is done manually using methods such as CPM or PERT. In case where the project is to be completed earlier than scheduled, the determination of activities, which are capable to be crashed, entails a new problem in a project management. A mathematical model is here proposed to solve the problem in a faster and a more accurate way. The solution could be obtained easier with the advantage of having the ability to specify optimally the activities that could be compressed to complete the project in a scheduled time with a minimum cost. The model is then applied in a project of ship maintenance with a procurement of normal and crash data time and cost. The solution of the model indicates which activities, and time requirement, could be compressed in order to complete the project in a scheduled time with a minimum cost. The model could be naturally applied to various projects.

OPTIMASI PEMILIHAN INGREDIEN DAN ALOKASI PENYIMPANAN BAHAN David Yunianto; Abdullah Shahab
Jurnal Teknobisnis Vol 1, No 1 (2005): Jurnal TEKNOBISNIS
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat- Institut Teknologi Sepuluh Nopember

The adverse climate of a business competition, especially in the realm of production of household commodities, enforces a business enterprise to apply a strategic decision about mixing ingredient and its inventory effectively. This decision entails the appropriate selection of ingredient within a minimum attainable cost.Optimization of ingredient selection and inventory was carried out in a detergent industry. Optimization was conducted employing the technique of Linear Programming with the incorporation of several relevant constraints. The optimization was focused on the optimal profit, taking account specifically the cost of material handling; this would necessitate the choice of suitable ingredients for manufacture of a certain product, and a decision about where these ingredients would be inventoried.In this study, the optimization was proven capable to increase the profit in a significant figure. The results of the optimization determined specifically the selection of the ingredients for each product according to the quality specified, and at the same time determined the allotment of the ingredients in the specified inventory.

Kekasaran dan Morfologi Hasil Pengelasan TIG Baja Tahan Karat 316 dengan Kadar Sulfur Berbeda Abdullah Shahab
Jurnal Teknik Mesin (Sinta 3) Vol. 12 No. 1 (2010): APRIL 2010
Publisher : Institute of Research and Community Outreach, Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar

The presence of impurities in stainless steel can unexpectedly create a problem in welding. The difference of a small amount of impurities, from heat to heat, can induce the inconsistency in welding especially in automatic welding. This study is conducted to asses the influence of sulfur content of the steel on morphology of weld which is represented by the variation of weld pool and surface roughness of weld. The effect of sulfur on surface roughness of weld is studied in TIG welding of 316 stainless steels with different sulfur content. The influence of sulfur on the weld geometry, characterized by the ratio of depth and width of the weld (D/W), is studied in welding with various parameters. The variation of the weld geometry is conjointly studied in relation to the surface roughness of weldment. The effect of sulfur is also studied using a stationary arc with different current and duration. The variation of the diameter of a circular pool and the degree of protuberance which possibly emerged beneath the specimen is related to the sulfur content of the steel. The results of the study show the salient effect of sulfur on the surface roughness of weld. The surface roughness of steel with high sulfur content always more perturbed than that of steel with lower one; the different movement of liquid, characteristic of these two steels is posited to explain the difference. Greater degree of roughness is accompanied by a greater value of the ratio D/W. The results of the study with stationary arc show some points of a paramount importance. The effect of sulfur which hitherto considered advantageous to the formation of a weld with a higher ratio of D/W, turn out to be effective only in a specific range of welding parameters. In a different range, the weld geometry is more influenced by the arc characteristic, the anode spot. Abstract in Bahasa Indonesia: Keberadaan elemen impuritis dalam baja tahan karat seringkali tanpa diduga bisa menimbulkan masalah dalam pengelasan. Perbedaan dengan kadar yang sangat kecil elemen impuritis, seperti sulfur, dari sebuah heat ke heat yang lain, bisa menimbulkan kesulitan terutama pada pengelasan secara otomatis. Penelitian ini bertujuan untuk melihat pengaruh kadar sulfur baja terhadap pembentukan morfologi lasan yang ditunjukkan dengan perbedaan kekasaran permukaan dan pembentukan kolam lasan yang berbeda. Pengaruh kadar sulfur terhadap kekasaran permukaan kolam lasan dipelajari dengan mengadakan pengelasan Tungsten Inert Gas baja tahan karat 316 dengan kadar sulfur yang berbeda. Variasi morfologi kolam lasan, penetrasi (P) dan lebar (L) kolam lasan dan rasio P/L dikaitkan dengan kekasaran permukaan. Pengaruh sulfur dipelajari juga dengan peleburan dengan arus dan durasi penyalaan yang bervariasi. Pengaruh sulfur ditunjukkan dengan variasi diameter kolam lasan berbentuk lingkaran dan juga pada derajat tonjolan yang mencuat dari bawah spesimen. Hasil penelitian menunjukkan bahwa kekasaran permukaan baja sulfur tinggi selalu lebih besar dibanding baja sulfur rendah. Arah aliran cairan yang berbeda diajukan untuk menjelaskan fenomena ini. Kekasaran yang lebih besar ini diikuti dengan harga P/L yang lebih berarti. Pengamatan pada hasil peleburan dengan busur stasioner menghasilkan kesimpulan yang menarik. Pengaruh sulfur dalam menentukan morfologi kolam lasan lewat fenomena arah aliran cairan hanya berlaku pada rentang tertentu parameter penyalaan busur. Pada rentang yang lain, morfologi kolam lasan lebih banyak ditentukan oleh karakteristik busur, seperti anode spot, ketimbang arah aliran cairan. Kata kunci: Pengelasan TIG; baja tahan karat 316; sulfur; morfologi lasan; anode spot.

Nurse Scheduling Optimation with Various Assignment Pattern at ABC Hospital Using Goal Programming Method Sigit Ananda Murwato; Abdullah Shahab
IPTEK Journal of Proceedings Series No 3 (2020): International Conference on Management of Technology, Innovation, and Project (MOTIP) 2
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2020i3.11228

In fulfilling health services in hospitals, the availability of human resources (HR) which includes doctors, nurses, midwives, and so on, plays a very important role. In terms of amount and dominant existence in the hospital in providing health services to patients is a nurse. The role of hospital management in maintaining the availability of nurses is to plan a good schedule. Without a good resource scheduling plan, the services will not be optimal and the costs will hard to control. This research aims to optimize the nurse scheduling. Existing schedule did not pay attention to specific time that have different load to another. Management feels that a lot of idle time is experienced by some nurses. Therefore, from the data that occurred in the past there will be observations that every 4 hours will occur how many services performed and how many nurses needed. Furthermore, by using Goal Programming method, several priority objectives are made, such as how to minimize the deviation of nurses needed in one shift or slot. Then how to minimize the excess target number of nurses who work in one week. And then minimize the excess number of nurses who work on the night shift. The suggested mathematical model has been implemented using Lingo Software. Work patterns have been suggested to improve schedules quality based on different load of services that occur in specific time. The suggested approach can be used for any similar staff scheduling problem in the next research.

Optimization of Travelling Water Screen (TWS) Components Replacement in Cooling Water System (Case Study on PLTGU Muara Tawar Blok 1) Arief Wicaksono; Abdullah Shahab
IPTEK Journal of Proceedings Series No 1 (2019): 4th International Seminar on Science and Technology 2018 (ISST 2018)
Publisher : Institut Teknologi Sepuluh Nopember

Traveling Water Screen (TWS) in cooling water system is one of the main cooling equipment of a Combined Cycle Gas Turbine (CCGT) generator, which has a considerable impact towards the steam turbine’s power output and thermal efficiency of the generator in general. This research aims to understand the distribution of TWS component failure which occurs in the filtration process of the cooling water system under the current operating condition, and operational expenditures correlated with it. The analysis started with the collection of TWS maintenance data between 2003 to 2017. Then, the distribution of failure is characterized by using available statistical software. Mathematical models were used to determine optimum replacement policy for each component, based on failure distribution data and replacement/maintenance cost. The optimum replacement interval and minimum replacement cost varies between TWS components. The optimum replacement intervals for each component are as follows: 43.4245 days for bearing bushing; 19.9785 days for bolt, sock head M.16; 40.9505 days for bolt, sock head M.12; 27.6088 days for rubber seal; 48.4359 days for pin, straight plain, 25.4 mm; 88.4978 days for ram, wiremesh; 69.471 days for pin, straight plain, 27/30 mm; and 29.2394 days for nut, hex M.8. The minimum replacement costs for each component are as follows: Rp4,383,400/day for bearing bushing; Rp5,706,850/day for bolt, sock head M.16; Rp12,671,400/day for bolt, sock head M.12; Rp7,247,630/day for rubber seal; Rp6,308,610/day for pin, straight plain, 25.4 mm; Rp5,522,590/day for ram, wiremesh; Rp5,032,190/day for pin, straight plain, 27/30 mm; and Rp4,770,530/day for nut, hex M.8. These findings were further integrated into the implementation of optimum maintenance strategy, especially for stock control, manpower resources smoothing, and maintenance expenditure planning in order to keep the performance of the generator

Title

Found 11 Documents
Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title Search

Found 11 Documents Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 11 Documents
Search