Computations of Compressible Two-Phase Flow Models Two-phase flow is generally understood as being a simultaneous flow of two different im- miscible phases separated by an infinitesimal thin interface. Phases are identified as ho- mogeneous parts of the fluid for which unique local state and transport properties can be defined. In most cases, phases are simply referred to as the state of matter, e.g. gas/vapor, liquid, or solid. Typical examples are the flow of liquid carrying vapor or gas bubbles, or the flow of gas carrying liquid droplets or solid particles. However, more complex flow pro- cesses may exist where the phase distribution is less well defined. This work is concerned with the numerical approximation of homogenized two-phase flow models. The models are obtained by averaging the balance laws for single phases and are non-strictly hyperbolic and non-conservative, i.e. they are not expressible in divergence form. The seven-equation two-phase models are regarded as well-established and can be applied to study various two- phase flow phenomena. However, physical and numerical difficulties are associated with these models. In most situations, the general physics of the models is not needed, thus, more compact models may be enough. For that reason, the reduced five- and six-equation models, deduced from the seven-equation models, are investigated in this dissertation. The five-equation model is obtained under the asymptotic limit of stiff velocity and pressure re- laxations, while the six-equation model assumes stiff velocity relaxation only. Our primary objective is to develop a deeper understanding of these models containing non-conservative derivatives and to numerically approximate them. The high order kinetic flux-vector split- ting (KFVS) scheme, the space-time conservation element and solution element (CESE) method, the high resolution central schemes, and the HLLC-type Riemann solvers are ap- plied to solve these models. Several test problems are carried out for all considered models and the numerical results of suggested schemes are compared with each other and with those available in the literature.
Tujuan dari penelitian ini untuk mengimplementasikan implementasi model waterfall dalam perancangan sistem surat perintah perjalanan dinas berbasis website dengan metode SDLC. Perancangan sistem Surat Perintah Perjalanan Dinas pada Badan Pusat Statistik Kabupaten Pesisir Selatan bertujuan untuk mengkomputerisasikan pembuatan dan pengolahan data Surat Perintah Perjalanan Dinas secara efisien dan efektif. Pengelolaan SPPD ini di rancang menggunakan teknologi informasi berbasis website. Metode perancangan yang akan digunakan yaitu metode SDLC dengan model waterfall yang prosesnya secara sistematis atau berurutan. Sistem mempermudah efektivitas kinerja proses pembuatan SPPD di Badan Pusat Statistik Kabupaten Pesisir Selatan, serta penyimpanan data yang telah di buat tersimpan dengan baik, keamanan data lebih terjamin dan bisa di akses kapan pun dan di mana pun, serta menyelesaikan permasalahan yang ada pada Badan Pusat Statistik Kab. Pesisir Selatan dalam melakukan penginputan data dan pembuatan laporan yang akurat dan tepat waktu
Pakistan Maintenance, Repair and Overhaul (MRO) sector companies are facing a significant competition among themselves. Aerospace spares supply chains are highly complex due to volatile and high demands. The dire predicament is further affected due to the highly competitive global market, characterized by other airlines and aerospace sector companies with more robust Electronic Supply Chain Management (ESCM) systems. Such a competitive environment demands more effective and efficacious supply chain management systems, implying a strong need by the MRO sector to embrace effective ESCM systems. This study was aimed at developing a framework for effective implementation of electronic supply chain management in aviation MRO sector of Pakistan to manage the ever-changing needs among the consumers as a result of tough competition and globalization. Study involved primarily quantitative analysis, however, four key independent/mediating variables were identified through content analysis. After content analysis, quantitative method was used to measure the impact of these variables on dependent variable (ESCM). For quantitative analysis, questionnaire was responded by 924 respondents from Pakistan’s aircraft MRO sector companies. Both SPSS and AMOS tools were used to analyse the impact of three independent and one mediating variable on ESCM. Results validation was also done through case study. Findings of study highlighted that all three independent variables (social influence, IT infrastructure and IT training) and mediating variable (IT competence) have significant effect on the dependent variable (ESCM implementation). Confirmatory factor analysis (structural equation modelling / AMOS) also confirmed a significant mediating effect of DEVELOPMENT OF FRAMEWORK FOR e-SCM IMPLEMENTATION ii IT Knowledge and IT Experience (Expanded factors of IT Competence) on ESCM implementation. The results indicate that significance of social influence has been central among the e-SCM adoption models. The research while analysing the impact of Information Technology (IT) variables on e-SCM, found that within IT infrastructure domain, key deficiencies among the MROs in Pakistan related largely to the human resource aspect. The study also highlights that role of IT deployment capability is not limited to the physical IT infrastructure. It must be balanced with managerial IT skills (e.g. IT knowledge management and experience in IT projects management) for effective linking of information flows across organizational boundaries. The research augments the existing literature that IT training can facilitate in ensuring seamless supply chain but this improvement could come through empowerment of employees specially those working in IT division. With regard to IT competence, this study highlights that its role cannot be underscored. IT competence was further expanded into Knowledge and Experience element. In the field of IT competence, the principal challenges were identified in IT experience domain, which seemed to be lacking within the Pakistan MRO industry. The study is unique in the aspects that e-SCM implementation in Pakistan’s MRO sector has not been reviewed in existing literature and secondly the study provides the structural composition of elements for e-SCM implementation in conjunction with Social Influence, IT Infrastructure, IT Training and IT Competence through an integrated framework. Study results may provide a guideline to the managers for increasing the scope and magnitude of e-SCM. The organizational capabilities identified in study results could provide a guideline to management while transforming their conventional supply chains into those based on the internet-based supply chain network.Improving upon the motivation, social impact value and IT competence/skill level through workshops, seminars, training programs and more investments for digitalization of systems could help in more smooth e-SCM implementation in MRO sector companies. Study highlights experience in IT projects along with general IT management in IT as the weak links in e SCM implementation. Findings of research work confirm that e-SCM implementation through combined effect of study variables are significant for enhancing companies’ performance (reduction in order lead times, better inventory management, life tracking etc.) as validated through case study as well. Limitations of study with future research directions have been discussed in last part of this thesis.