ABSTRACT:Compressive strength tests were carried out on six mortar cubes with cement replaced by rice husk ash (RHA) at five levels (0, 10, 20, 30, 40 and 50%). After the curing age of 3, 7, 14 and 28 days. The compressive strengths of the cubes at 10% replacement were 12. 60, 14.20, 22.10, 28.50 and 36.30 N/mm 2 respectively and increased with age of curing but decreased with increase in RHA content for all mixes. The chemical analysis of the rice husk ash revealed high amount of silica (68.12%), alumina (1.01%) and oxides such as calcium oxide (1.01%) and iron oxide (0.78%) responsible for strength, soundness and setting of the concrete. It also contained high amount of magnesia (1.31%) which is responsible for the unsoundness. This result, therefore, indicated that RHA can be used as cement substitute at 10% and 20% replacement and 14 and 28 day curing age.
To respond to current and future consumer demands in air cargo delivery, an Unmanned Air Vehicle (UAV) Cargo System is proposed. It would provide a safe, automated air cargo system which could be operational and more cost effective than the existing system. The system could potentially operate twenty four hours a day, seven days a week and provide guaranteed one business day delivery service. For the UAV Cargo System to be in full operation it is assumed that the operational ground infrastructure for airport-independent operations is in place, accurate, and reliable, and the data link communication between Air Traffic Control (ATC) and the UAV are in place. The analysis approach consists of evaluating the operational cost of the system by performing a trade-off analysis to measure the feasibility of the UAV Cargo System for a business case; simulating the landing and en-route portion of the alternative proposed in order to analyze the operational performance of the system and to provide the best solution to the problem; and analyzing the safety and reliability of the system by performing failure rate analysis of the redundancy systems. UNMANNED AERIAL VEHICLE (UAV) CARGO SYSTEM Senior Design Capstone ProjectKevin (Kook-In) Han
Abstract. CV Nebulae Cymbals is a company that produces drum cymbals. In the production process, several problems are included in the waste. To achieve good productivity, efforts are needed to reduce waste. In this study, the method used is Lean Manufacturing and several tools is used, including Value Stream Mapping to map the flow of the production process and Process Activity Mapping (PAM) to describe the activities that occur. In identifying waste, the method used is the Waste Assessment Model (WAM). The identified waste is then grouped according to the seven waste categories. The final result of the WAM method produces a ranking of each waste. Based on the waste ranks, then the waste with the 3 highest ranks was chosen, namely the waste in the Motion category with a percentage of 20.20%, the Waiting category waste with a percentage of 17.18%, and waste in the Transportation category with a percentage of 16.46%. Analysis of the root causes of waste is carried out using the Ishikawa diagram based on the 3 highest wastes. Then arrange improvement proposals using 5W+1H. The proposed improvements include arranging goods, rescheduling production, providing and updating facilities, improving layouts, and making Standard Operating Procedures (SOP). After being given recommendations for improvement, it can be described as a Future State Value Stream Mapping which contains an estimate of increasing the Process Cycle Efficiency (PCE) value from 54% to 77% in the hope of increasing company productivity. Abstrak. CV Nebulae Cymbals merupakan perusahaan yang memproduksi simbal drum. Dalam proses produksinya, terdapat beberapa permasalahan yang termasuk ke dalam waste atau pemborosan. Demi tercapainya produktivitas yang baik, diperlukan adanya upaya untuk mereduksi waste. Dalam penelitian ini, metode yang digunakan adalah Lean Manufactuing, dan berbagai tools yang digunakan, antara lain Value Stream Mapping, yang dapat memetakan alur proses produksi dan Process Activity Mapping (PAM) untuk menjabarkan aktivitas-aktivitas yang terjadi. Dalam mengidentifikasi waste, metode yang digunakan yaitu Waste Assessment Model (WAM). Waste yang telah diidentifikasi kemudian dikelompokan menurut kategori seven waste. Hasil akhir dari metode WAM menghasilkan ranking dari setiap waste. Berdasarkan rangking waste tersebut, kemudian dipilihlah waste dengan 3 rank tertinggi yaitu waste kategori Motion dengan persentase sebesar 20,20%, waste kategori Waiting dengan persentase sebesar 17,18%, dan waste kategori Transportation dengan persentase sebesar 16,46%. Analisa akar penyebab waste dilakukan dengan menggunakan diagram Ishikawa berdasarkan 3 waste tertinggi. Kemudian menyusun usulan perbaikan menggunakan 5W+1H. Perbaikan yang diusulkan diantaranya adalah melakukan penataan barang, penjadwalan produksi kembali, penyediaan dan pembaharuan fasilitas, memperbaiki layout, dan membuat Prosedur Operasi Standar atau SOP. Setelah diberikan rekomendasi perbaikan, maka dapat digambarkan Future State Value Stream Mapping yang berisi perkiraan peningkatan nilai Process Cycle Efficiency (PCE) dari 54% menjadi 77% dengan harapan dapat meningkatkan produktivitas perusahaan.
In the batch production, the use of a single machine for several stages of the processes will result in waiting time of production batch to be long. It will cause an increase in work in process (WIP) inventory cost. CNC-machining centre is a type of CNC machine that can carries out several stages of processes singly. In some cases, this machine is often single used to make a product through several stages of processes, from raw material to end product. One of the reasons to use a single machine is to avoid transfer from one stage (machine) to next machine. However, single use causes inventory to accumulate due to long waiting times. The objective of this research is to reduce the WIP inventory cost at the CNC-machining centre. Scheduling to minimize WIP inventory cost is done through two steps. First step, divide number of stages of processes to be assigned to m serial CNC-machining centers. Second step, determine transfer batch size is smaller than the production batch size to be transferred to the next stages. The results of this research indicate that there is a reduction in WIP inventory cost by 53.47 percent. Scheduling multi-stage batch production on m machines with small transfer batch size will reduce WIP inventory cost.
This paper discusses about a company that adopts make-to-order strategy because the company does not have enough fund to provide raw material. The raw material is ordered when the order is received. It occurs a very long customer lead time due to the production process must wait for the arrival of material. Consequently, the company cannot meet the customer order at the due date, and the company should give a discount of 25 - 30% of the total purchases. This research aims at reducing customer lead time by determining a decoupling point. The result shows that the decoupling point is placed between the procurement of raw materials and the manufacturing process. The decoupling point denotes a boundary between the make-to-stock strategy in the previous process, and the make-to-order strategy for the process afterwards. The lead time customer is then considered start from the decoupling point to the due date.
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