112,790 research outputs found
Integrated Tolerance and Fixture Layout Design for Compliant Sheet Metal Assemblies
Part tolerances and fixture layouts are two pivotal factors in the geometrical quality of\ua0a compliant assembly. The independent design and optimization of these factors for compliant\ua0assemblies have been thoroughly studied. However, this paper presents the dependency of these\ua0factors and, consequently, the demand for an integrated design of them. A method is developed\ua0in order to address this issue by utilizing compliant variation simulation tools and evolutionary\ua0optimization algorithms. Thereby, integrated and non-integrated optimization of the tolerances and\ua0fixture layouts are conducted for an industrial sample case. The objective of this optimization is\ua0defined as minimizing the production cost while fulfilling the geometrical requirements. The results\ua0evidence the superiority of the integrated approach to the non-integrated in terms of the production\ua0cost and geometrical quality of the assemblies
Scalable Coordinated Beamforming for Dense Wireless Cooperative Networks
To meet the ever growing demand for both high throughput and uniform coverage
in future wireless networks, dense network deployment will be ubiquitous, for
which co- operation among the access points is critical. Considering the
computational complexity of designing coordinated beamformers for dense
networks, low-complexity and suboptimal precoding strategies are often adopted.
However, it is not clear how much performance loss will be caused. To enable
optimal coordinated beamforming, in this paper, we propose a framework to
design a scalable beamforming algorithm based on the alternative direction
method of multipliers (ADMM) method. Specifically, we first propose to apply
the matrix stuffing technique to transform the original optimization problem to
an equivalent ADMM-compliant problem, which is much more efficient than the
widely-used modeling framework CVX. We will then propose to use the ADMM
algorithm, a.k.a. the operator splitting method, to solve the transformed
ADMM-compliant problem efficiently. In particular, the subproblems of the ADMM
algorithm at each iteration can be solved with closed-forms and in parallel.
Simulation results show that the proposed techniques can result in significant
computational efficiency compared to the state- of-the-art interior-point
solvers. Furthermore, the simulation results demonstrate that the optimal
coordinated beamforming can significantly improve the system performance
compared to sub-optimal zero forcing beamforming
SYARIAH COMPLIANT HOTEL: THE CONCEPT AND PRACTICES
The demand for and supply of Islamic hospitality services has been affected positively by the increasing number of Islamic followers globally and positive tourism trends. This study is discussing on  Syariah Compliant hotel concept and practices, the outline of operations, design and finance system. Therefore the hotel management must try to address the need to enhance the development of Islamic Tourism  through the improvement of its current tourism infrastructure, focusing on the establishment of Syariah-Compliant Hotel using a conceptual framework developed specifically to expose the factors required for any Muslim country to be successful in todayâs highly competitive hospitality market
Hierarchical elimination-by-aspects and nested logit models of stated preferences for alternative fuel vehicles
1. INTRODUCTION
Since the late 1960s, transport demand analysis has been the context for significant developments in model forms for the representation of discrete choice behaviour. Such developments have adhered almost exclusively to
the behavioural paradigm of Random Utility Maximisation (RUM), first proposed by Marschak (1960) and Block and Marschak (1960). A common argument for the allegiance to RUM is that it ensures consistency with the fundamental axioms of microeconomic consumer theory and, it follows,
permits interface between the demand model and the concepts of welfare economics (e.g. Koppelman and Wen, 2001). The desire to better represent observed choice, which has driven developments in RUM models, has been somewhat at odds, however, with the frequent assault on the utility maximisation paradigm, and by implication
RUM, from a range of literatures. This critique has challenged the empirical validity of the fundamental axioms (e.g. Kahneman and Tversky, 2000; Mclntosh and Ryan, 2002; Saelensmide, 1999) and, more generally, the
realism of the notion of instrumental rationality inherent in utility maximisation (e.g. Hargreaves-Heap, 1992; McFadden, 1999; Camerer, 1998). Emanating from these literatures has been an alternative family of so-called
non-RUM models, which seek to offer greater realism in the representation of how individuals actually process choice tasks. The workshop on Methodological Developments at the 2000 Conference of the International Association for Travel Behaviour Research concluded: 'Non-RUM models
deserve to be evaluated side-by-side with RUM models to determine their practicality, ability to describe behaviour, and usefulness for transportation policy. The research agenda should include tests of these models' (Bolduc and McFadden, 2001 p326). The present paper, together with a companion paper, Batley and Daly (2003), offer a timely contribution to this research
priority. Batley and Daly (2003) present a detailed account of the theoretical derivation of RUM, and consider the relationships of two specific RUM forms;
nested logit [NL] (Ben-Akiva, 1974; Williams, 1977; Daly and Zachary, 1976; McFadden, 1978) and recursive nested extreme value [RNEV] (Daly, 2001 ; Bierlaire, 2002; Daly and Bierlaire, 2003); to two specific non-RUM forms;
elimination-by-aspects [EBA] (Tversky, 1972a, 1972b) and hierarchical EBA [HEBA] (Tversky and Sattath, 1979). In particular, Batley and Daly (2003) establish conditions under which NL and RNEV derive equivalent choice
probabilities to HEBA and EBA, respectively. These findings would seem to ameliorate the concern that the application of RUM models to data generated by non-RUM choice processes could introduce significant biases. That
aside, substantive issues remain as to how non-RUM models can best be specified so as to yield useful and robust information in both estimation and forecasting contexts, and how their empirical performance compares with
RUM models. Such issues are the focus of the present paper, which applies non-RUM models to a real empirical context
Pembangunan Modul Pengajaran Kendiri (MPK) keusahawanan dalam topik isu keusahawanan bagi pelajar diploma di politeknik
Terdapat pelbagai kaedah pembelajaran yang telah diperkenalkan termasuklah
kaedah pembelajaran yang menggunakan pendekatan pembelajaran bermodul secara
kendiri. Kajian ini adalah bertujuan untuk mengkaji kesesuaian Modul Pengajaran
Kendiri Keusahawanan dalam topik Isu Keusahawanan yang telah dihasilkan bagi
pelajar yang mengikuti pengajian Diploma di Jabatan Perdagangan Politeknik. Antara
aspek yang dikaji ialah untuk menilai sama ada rekabentuk modul yang dihasilkan dapat
memenuhi ciri-ciri modul yang baik, MPK yang dihasilkan dapat membantu mencapai
objektif pembelajaran, MPK ini bersifat mesra pengguna dan MPK yang dihasilkan
membantu pensyarah menyampaikan pengajarannya dengan lebih berkesan. Kajian ini
dilakukan ke atas 110 orang pelajar semester en am yang mengikuti pengajian diploma
dan 4 orang pensyarah yang mengajar subjek Keusahawanan di Jabatan Perdagangan
Politeknik Sultan Salahuddin Abdul Aziz Shah, Selangor. Kaedah analisa data yang
digunakan dalam kajian ini ialah skor min dan peratus. Hasil daripada kajian ini
menunjukkan bahawa rekabentuk modul yang dihasilkan memenuhi ciri-ciri modul
yang baik, MPK ini membantu untuk mencapai objektif pembelajaran, MPK ini
bersifat mesra pengguna dan MPK yang dihasilkan dapat membantu pensyarah
menyampaikan pengajarannya dengan lebih berkesan. Ini bermakna secara
keseluruhannya, hasil kajian menunjukkan bahawa modul yang dihasilkan oleh pengkaji
adalah sesuai digunakan oleh pelajar-pelajar semester enam yang mengikuti pengajian
diploma di Jabatan Perdagangan peringkat politeknik. Seterusnya, beberapa pandangan
telah dikemukakan bagi meningkatkan rnutu dan kualiti MPK yang dihasilkan. Semoga
kajian ini dapat memberi manfaat kepada mereka yang terlibat dalam bidang
pendidikan
Simplified modelling of air source heat pumps producing detailed results
Created by the Building Research Establishment (BRE), the Standard Assessment Procedure (SAP) is the UK Governmentâs recommended method of assessing the energy ratings of dwellings. Modelling future complex dwellings, and their servicing systems, will require a more advanced calculation which is as simple as SAP to use but can produce more detailed results. This paper extends a novel advanced dynamic calculation method (IDEAS â Inverse Dynamics based Energy Analysis and Simulation) of assessing the controllability of a building and its servicing systems. IDEAS produces SAP compliant results and allows confident (i.e. calibrated in SAP) predictions to be made regarding the impact of novel heating and renewable energy systems. This paper describes the addition of an Air Source Heat Pump (ASHP) model to IDEAS. This allows for detailed analysis to be made of ASHPs in a SAP compliant framework. The benefits of using the IDEAS method is highlighted with capabilities outwith the scope of SAP also possible. For example, IDEAS can be used as sizing tool for a heating system in a building
Beyond Antimalarial Stock-outs: Implications of Health Provider Compliance on Out-of-Pocket Expenditure during Care-Seeking for Fever in South East Tanzania.
To better understand how stock-outs of the first line antimalarial, Artemisinin-based Combination Therapy (ACT) and other non-compliant health worker behaviour, influence household expenditures during care-seeking for fever in the Ulanga District in Tanzania. We combined weekly ACT stock data for the period 2009-2011 from six health facilities in the Ulanga District in Tanzania, together with household data from 333 respondents on the cost of fever care-seeking in Ulanga during the same time period to establish how health seeking behaviour and expenditure might vary depending on ACT availability in their nearest health facility. Irrespective of ACT stock-outs, more than half (58%) of respondents sought initial care in the public sector, the remainder seeking care in the private sector where expenditure was higher by 19%. Over half (54%) of respondents who went to the public sector reported incidences of non-compliant behaviour by the attending health worker (e.g. charging those who were eligible for free service or referring patients to the private sector despite ACT stock), which increased household expenditure per fever episode from USD0.14 to USD1.76. ACT stock-outs were considered to be the result of non-compliant behaviour of others in the health system and increased household expenditure by 21%; however we lacked sufficient statistical power to confirm this finding. System design and governance challenges in the Tanzanian health system have resulted in numerous ACT stock-outs and frequent non-compliant public sector health worker behaviour, both of which increase out-of-pocket health expenditure. Interventions are urgently needed to ensure a stable supply of ACT in the public sector and increase health worker accountability
- âŚ