Hasil Pencarian  ::  Simpan CSV :: Kembali

"ABSTRACTTraditional approaches in constructing response surface models typically ignore model uncertainty. If the relationship between the input factors and output characteristics of a process is very complex, traditional model building approaches may have limited effectiveness. In this paper, we propose a multi model ensemble and then implement this ensemble model to optimize the process performance. To form a multi model ensemble, we need to determine the weights of the different models, that is, values indicating relative importance among the models. To determine the weights, a hybrid weighting method is proposed, in which both global and local weighting methods are taken into account. Based on the hybrid weights of different models, a multi model ensemble is built and optimized. An example is illustrated to verify the effectiveness of the proposed approach. The results show that the proposed model can achieve more accurate predictive capability and that a better process improvement is reached."

"Dengan permintaan hidrogen yang tinggi di masa depan, pemanfaatan energi dingin tampaknya menjadi solusi alternatif untuk meningkatkan rantai ekonomi hidrogen dengan memaksimalkan pemanfaatan limbah energi dingin selama regasifikasi. Suhu rendah hidrogen cair (-253℃ pada 1 atm) akan memberikan beragam aplikasi yang dapat diimplementasikan. Makalah ini mengusulkan pembangkit daya dan unit pemisahan udara sebagai proses integrasi dari regasifikasi hidrogen cair. Untuk mencapai desain proses terbaik, pemilihan proses dibuat dengan mempertimbangkan tingginya pembangkitan daya dan rendahnya kerusakan eksergi. Desain proses terpilih akan diintegrasikan dengan unit pemisahan udara dengan 4 skenario laju alir dan dioptimasi untuk mendapatkan kondisi ideal dengan maksimal energi listrik hasil dan kerusakan eksergi yang minimum. Solusi ideal setiap scenario akan dievaluasi keekonomiannya. Dari hasil pemilihan proses, cascade rankine cycle mampu memulihkan energi pencairan hidrogen hingga 11,46 % dan menghasilkan kerusakan eksergi yang paling minim. Cascade rankine cycle kemudian diintegrasikan dengan unit pemisahan udara dan dioptimasi. Dari hasil simulasi, semakin tinggi laju alir udara akan menghasilkan energi listrik yang semakin rendah tetapi mampu mengurangi kerusakan eksergi hingga 1700 kW. Dari hasil perhitungan, skenario D, dengan laju alir 12000 kg/jam mampu memberikan internal rate of return paling tinggi (23,96%) dan payback period tersingkat 5,14 tahun dibanding dengan skenario lainnya. 

---

With the future's high demand for hydrogen, utilizing cold energy appears to be an alternative solution to enhance the hydrogen economic chain by maximizing the use of cold energy waste during regasification. The low temperature of liquid hydrogen (-253℃ at 1 atm) offers various applicable implementations. This paper proposes integrating a power plant and an air separation unit with the liquid hydrogen regasification process. To achieve the optimal process design, the selection process considers both high power generation and low exergy destruction. The chosen process design will be integrated with the air separation unit under four different flow rate scenarios and optimized to obtain ideal conditions, maximizing electrical energy output and minimizing exergy destruction. The economic feasibility of the ideal solution for each scenario will be evaluated. Based on the process selection results, the cascade Rankine cycle can recover up to 11.46% of the hydrogen liquefaction energy and produce the least exergy destruction. The cascade Rankine cycle is then integrated with the air separation unit and optimized. Simulation results indicate that higher air flow rates yield lower electrical energy but can reduce exergy destruction by up to 1700 kW. According to economic calculations, scenario D, with a flow rate of 12,000 kg/hour, provides the highest internal rate of return (23.96%) and the shortest payback period of 5.14 years compared to other scenarios."

"This book is the first attempt to summarize the existing scientific methods and to present new developments and results in this field. First of all, a large array of functional relationships was elaborated and described in details in a voluminous chapter. Beside the strict mathematical optimization methods, an engineering approach is outlined and demonstrated in many worked examples. The essence of this approach is a recognition that, in many practical cases, the optimum is uniquely determined by a particular constraint.The scientific methods of engineering design of wood products are discussed, compared and illustrated with numerical examples. Special attention is paid to the joint elements and, for their easy optimum selection, new similarity equations are developed and illustrated by practical examples.In the last chapter, the general principles of optimum manufacture, interactions among product structure, degree of automation and optimized production technology are discussed. The main woodworking operations are also described and reference is given for optimum selection of their operational parameters.In the Appendix, over 50 colour pictures demonstrate the unique ornamental properties of various timber materials. "

"This book describes different approaches for solving industrial problems like product design, process optimization, quality enhancement, productivity improvement and cost minimization. Several optimization techniques are described. The book covers case studies on the applications of classical as well as evolutionary and swarm optimization tools for solving industrial issues. The content is very helpful for industry personnel, particularly engineers from the Operation, R&D and Quality Assurance sectors, and also the academic researchers of different engineering and/or business administration background."

"This book describes an effective framework for setting the right process parameters and new mold design to reduce the current plastic defects in injection molding. It presents a new approach for the optimization of injection molding process via (i) a new mold runner design which leads to 20 percent reduction in scrap rate, 2.5 percent reduction in manufacturing time, and easier ejection of injected part, (ii) a new mold gate design which leads to less plastic defects; and (iii) the introduction of a number of promising alternatives with high moldability indices. Besides presenting important developments of relevance academic research, the book also includes useful information for people working in the injection molding industry, especially in the green manufacturing field."