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Risk Analysis Using Job Safety Analysis-Fuzzy Integration for Ship Maintenance Operation
Get PDFShipyard is an industry engaged in the maintenance and repair of ships and constructing a new ship. In ship repair operations, there are many activities in this operation. Propeller inspection, blasting, replating, welding, general work, electric work is an activity in ship repair operation. This research proposed a methodology to risk analysis ship maintenance operation, integrating Job Safety Analysis (JSA) with Bayesian Network (BN) and Fuzzy Inferences System (FIS). JSA method is used to find the hazards and the consequences of the maintenance operation. BN is developed for probability calculating of likelihood factors. Meanwhile, the FIS is used as a method to calculate the risk level. The FIS using the Mamdani algorithm based on the expert’s knowledge and experience. The integration of three methods is used to complete the risk assessment for replating activities. The proposed method is used to find out the risk level of replating activity on ship maintenance. Based on the result, the proposed model is more accurate, precise, and flexible depending on the basic factor that influences the operation. It would help to reduce the potential accident on the operation. This proposed method could be the other option as a tool to calculate risk assessment in other operations
Users’ Satisfaction with Internet Service Performance-Based on User Log
Get PDFWe are currently on the cusp of a digital era when people engage Internet services (Int-Sevs) ceaselessly for sundry purposes such as learning, teaching, and research. However, the lack of sufficient understanding of user satisfaction still poses a huge challenge to Int-Sevs adaption to users’ dynamic needs and the provision of required services in real-time within the university’s context. This understanding is needful concerning what influences the performance of the Int-Sevs of a university. This paper, therefore, analyses the user log of about 65000 log items generated by 120 users of a university’s internet services that were collected over three months. The mixed-method approach was adopted. Thus, the two-step clustering and crosstabulation techniques were applied to identify natural groupings and examine them for existing relationships (respectively) to determine the existence of user satisfaction. The results showed a significant association and relationship between user satisfaction and Key Performance Indicators (KPIs). The study concluded that with data and efficient techniques, KPIs with user-centric criteria like user satisfaction could be investigated to find what influences the performance of a university’s IntSevs. The quality of users’ experience was omitted and left to be considered in the future in a conceivably longitudinal study
Analysis The Effect of Bidding Process on Project Performance in PT Pelabuhan Indonesia III (Persero)
Get PDFBased on investment data in PT Pelabuhan Indonesia III (Persero) with asset code road and construction, also port facility construction in PT Pelabuhan Indonesia III (Persero) 2017 – 2018, there are 65 projects of physical construction. In the bidding process, to assess competence and business ability, also other requirements from the provider with stages of administration evaluation, technical evaluation and bid price from contractor. In 65 investment projects there are 18 projects fined. This research took 65 samples. While secondary data was collected from document of eligible awards of bidding on investment project in 2017–2018 in PT Pelabuhan Indonesia III (Persero) with asset code road and construction, also port facility. Analysis used was Structural Equation Modeling (SEM). The result of this research conclude that bidding process significantly affects to project performance variabl
Segmentation Analysis of Students in X Course with RFM Model and Clustering
Get PDFIn the business world, the competition to maintain and obtain more customers has become tougher. The presence of new players entering the market is driven by the developments of internet and advertisement. The X guitar course is an institution engaged in the field of non-formal education services. The customers are the course student that has made the payment transaction. The map of customer segmentation is one of the most important components in finding the main needs of each customer. Know the main needs of each customer is expected to increase the customer’s loyalty. Customer segmentation can be done by using the clustering method through a data mining approach in the form of RFM (Recency, Frequency and Monetary) Models. Recency is the data of the last payment transaction date. Frequency shows the number of course payment transactions. Monetary comes from the nominal amount of the transaction. RFM data is combined with the Fuzzy Gustafson-Kessel and K-Means clustering method to produce output in the form of k-clusters of customer. The formed segment is expected to represent the need of customers that vary by using validation process with the Global Silhouette Index. The customer population of the course is 225 students. It has been concluded that the RFM score for each subject by using 3 FGK clusters is the optimum cluster model with the largest Silhouette Index, which is 0.523. This research is expected to provide an in-depth analysis of customer segmentation for X guitar course
Pembuatan Paduan Tembaga Sebagai Bahan Baku Uang Logam
No full textUmumnya perunggu digunakan sebagai material untuk perhiasan, medali dan koin mata uang, karena paduan logam ini memberikan warna yang baik dan kekerasan yang relatif tinggi. Indonesia pernah menggunakan perunggu aluminium untuk koin mata uang. Khusus untuk koin mata uang, persoalannya adalah bahwa material dasar untuk pembuatan koin ini diimpor dari luar negeri sehingga menyebabkan tingginya biaya pembuatan koin. Dalam kenyataannya Indonesia memiliki sumber yang memedai untuk menyediakan material dasar untuk memproduksi paduan logam ini. Makalah ini membahas studi pembuatan paduan logam berbasis Cu-Al-Sn untuk kegunaan sebagai bahan koin uang logam. Logam dasar yang digunakan, yaitu tembaga, timah dan aluminium diperoleh dari PT. Smelting, PT. Inalum dan PT. Timah. Sebanyak 12 variasi paduan dibuat untuk kemudian diuji sifat fisika dan sifat mekanis serta pengamatan struktur mikro. Semua hasil paduan yang dibuat dibandingkan dengan uang logam yang pernah digunakan sebelumnya yaitu koin Rp. 500,-. Hasil studi menunjukkan bahwa penambahan Sn dan Al ke dalam paduan Cu meningkatkan kekerasan dan menurunkan berat jenis paduan logam yang dihasilkan, tetapi pengotor Fe menurunkan ukuran partikel endapan. Hasil percobaan menunjukkan bahwa dijumpai empat komposisi paduan yang memiliki sifat yang lebih baik dibandingkan dengan paduan logam yang pernah digunakan untuk koin Rp. 500,-
Resource-constrained project scheduling with ant colony optimization algorithm
Get PDFResource allocation commonly becomes one of the critical problems in project scheduling. This issue usually occurs because project managers estimate the schedule of activities and network time without considering resource availability. Resource-Constrained Project Scheduling Problem (RCPSP) links to the allocation of resource or set of resources into certain activities in order to accomplish particular objectives. Various approaches have been performed to overcome RCPSP, including the heuristic approach. In this research, we used the Ant Colony Algorithm in solving RCPSP. We used 11 examples of projects with dissimilarity in-network and several activities. The implementation of the Ant Colony Algorithm resulted in the percentage of a near-optimal solution of 63.64%. Besides, the duration obtained from the algorithm above the manual scheduling (assumed optimal) was only 4.29%. Sensitivity analysis was performed to understand how substantial the changes of ACO parameters influenced the result obtained from the algorithm. Based on the result, we could conclude that the parameters of ACO have no significant effect to project duration
Strength Reduction Factor of Square Reinforced Concrete Column Using Monte Carlo Simulation
No full textThis paper investigates the strength reduction factor (f) of reinforced concrete (RC) columns using Monte-Carlo simulation (MCS). The main objective of this paper is to evaluate the strength reduction factor of the RC using the authors' developed code. This code is important for further research to check other important effects when high-strength materials are used. The investigated RC column concrete compressive strengths (fc) are 40 and 60 MPa while the rebar strengths (fy) are set to 320, 400, and 500 MPa. Fiber-based cross-sectional analysis is used to compute the axial-moment interaction capacity of the RC column. The concrete compressive block is used to model the concrete contribution and the bilinear stress-strain model is adopted for the rebar. These simplifications can reduce the difficulties when solving the equilibrium of the forces in the sectional analysis. The parameters used in the sensitivity analysis of the strength reduction factor (f) are the concrete compressive strength (fc), the rebar yield strength (fy), the longitudinal rebar ratio (r), and the column size (b,h). The effect of the coefficient of variations for each material on the resistance variation coefficient of the RC is also investigated. From the analysis, it can be concluded that when the RC column falls in the tension-controlled region, the obtained strength reduction factor is 0.93 which is slightly higher than the value of f in ACI 318-19. On the other hand, when the RC column falls in the compression-controlled region, the obtained strength reduction factor is 0.6 which is lower than the value of f in ACI 318-19 which is 0.65
Penerapan Pencahayaan Buatan Terhadap Karya di Ruang Galeri Foto pada Perancangan Interior Pusat Fotografi di Bandung
Get PDFABSTRAKGaleri merupakan ruangan yang digunakan untuk mempamerkan karya seni. Galeri dapat dijadikan sebagai tempat untuk kegiatan rekreasi, hiburan, edukasi, bisnis, serta apresiasi kepada seniman. Galeri foto merupakan ruangan yang mempamerkan karya-karya fotografi dari para fotografer. Dalam ruang galeri, peran pencahayaan buatan terhadap karya yang di pamerkan cukup penting. Dengan pencahayaan buatan dapat menonjolkan serta memfokuskan para pengunjung ke karya. Dengan pengaturan pencahayaan buatan, juga dapat menimbulkan kesan-kesan tertentu terhadap karya. Penggunaan pencahayaan buatan lebih baik dibandingkan pencahayaan alami, dimana pencahayaan alami lebih rentan dapat merusak karya dari sinar ultraviolet. Pada studi kasus perancangan pusat fotografi ini, pengaplikasian pencahayaan pada ruang galeri dapat memberikan kesan-kesan tertentu terhadap karya, dengan pengaturan dari arah cahaya, jenis, dan teknik yang digunakan pada ruangan.Kata kunci: pencahayaan, galeri foto, pusat fotografi ABSTRACTThe gallery is a room used to display art. The gallery can be used as a place for recreation, entertainment, education, business, and appreciation for artists. The photo gallery is a room that shows artworks by photographers. In the gallery space, the role of artificial lighting in photos is quite important. Artificial lighting can highlight and focus the visitors to the artworks. it settings can also make impressions on the work. The use of artificial lighting is better than natural lighting, where natural lighting is more vulnerable to damage the photos because ultraviolet light. In this case, the application of lighting in the gallery space can give certain impressions to the work, with the setting of the light direction, type, technique, and the amount of lumens used in the room to comply with the standards.Keywords: lighting, photo gallery, photography center
Synthesis and Characterization of Zeolitic Imidazolate Framework-8 (ZIF-8)/Al2O3 Composite
Get PDFMetal-organic framework (MOF) such as ZIF-8 is the tremendous porous material applied in many fields due to high specific surface area and excellent regularity of pores. One technique to improve the physical properties of ZIF-8 with the formation of a composite between a metal oxide and MOF. ZIF-8 and ZIF-8/Al2O3 were successfully synthesized by the solvothermal method with an Al variation of 19%, 38%, and 76%. The ZIF-8/Al2O3 were characterized by XRD, FTIR, SEM, and N2 Physisorption. The diffractogram shows that the appearing of ZIF-8’s peak on 2θ = 7.26; 10.41, 12.66, 16.41, and 17.95°. The morphological of ZIF-8 crystals had a cubic shape. Then the ZIF-8/Al2O3 had different shapes with ZIF-8. Based on the FTIR result, the Zn-N peak appears on 420 cm−1, which indicates the bonding between metal and organic ligand for ZIF-8/Al2O3 has an additional spike on 825 cm−1 due to the vibration of Al−O− Al