An additive manufacturing oriented design approach to mechanical assemblies

Germain Sossou,Frédéric Demoly,Ghislain Montavon,Samuel Gomes 한국CDE학회 2018 Journal of computational design and engineering Vol.5 No.1

Firstly introduced as a prototyping process, additive manufacturing (AM) is being more and more considered as a fully-edged manufacturing process. The number of AM processes, along with the range of processed materials are expanding. AM has made manufacturable shapes that were too difficult (or even impossible) to manufacture with conventional technologies. This has promoted a shift in engineering design, from conventional design for manufacturing and assembly to design for additive manufacturing (DFAM). Research efforts into the DFAM field have been mostly dedicated to part’s design, which is actually a requirement for a better industrial adoption. This has given rise to topologically optimized and/or latticed designs. However, since AM is also capable of manufacturing fully functional assemblies requiring a few or no assembly operations, there is a need for DFAM methodologies tackling product’s development more holistically, and which are, therefore, dedicated to assembly design. Considering all the manufacturing issues related to AM of assembly-free mechanisms and available post-processing capabilities, this paper proposes a top-down assembly design methodology for AM in a proactive manner. Such an approach, can be seen as the beginning of a shift from conventional design for assembly (DFA) to a new paradigm. From a product’s concept and a selected AM technology, the approach first provides assistance in the definition of the product architecture so that both functionality and successful manufacturing (including post-processing) are ensured. Particularly, build-orientation and downstream processes’ characteristics are taken into account early in the design process. Secondly, for the functional flow (energy, material, signal) to be appropriately conveyed by the right amount of matter, the methodology provides guidance into how the components can be designed in a minimalism fashion leveraging the shape complexity afforded by AM. A mechanical assembly as case study is presented to illustrate the DFAM methodology. It is found that clearances and material (be it raw unprocessed material or support structures) within them plays a pivotal role in a successful assembly’s design to be additively manufactured. In addition, the methodology for components’ design proves to be an efficient alternative to topology optimization. Though, the approach can be extended by considering a strategy for part consolidation and the possibility to manufacture the assemblies with more than one AM process. As regards components’ design, considering anisotropy can also improved the approach.

Sea, Connecting the Dots: On the Cusp of Greatness

Germaine Tyo,Jasper Low Cheng En,Lee Jia En,Too Fang Jing,Andrew Karl Delios Academy of Asian Business (AAB) 2019 Academy of Asian Business Review Vol.5 No.2

Sea Limited (formerly Garena Limited) was founded in Singapore in 2009 as a digital entertainment services provider. Since then, Sea has ventured into digital financial services and e-commerce, achieved “unicorn” status, and undergone a successful Initial Public Offering. Sea has now arrived at a crucial juncture in its ascent and must make several important decisions to reach its next milestone. In 2014, Sea launched its digital financial services business: AirPay. AirPay was born out of necessity and strategy as part of Garena’s solution to avoid paying exorbitant transaction fees through third-party transaction services and to act as the foundation of other platforms in Sea’s development pipeline. Following AirPay, Sea launched its e-commerce platform: Shopee. Shopee was Sea’s highly ambitious and aggressive entry into a hotly contested space. Sea has invested significant resources into Shopee which have reaped correspondingly encouraging results. Keys to Sea’s success lie in its service orientation, adaptability, and the speed and decisiveness exhibited in the execution of strategy. These traits have allowed Sea to design the right platforms and products, change with the times and boldly implement planned changes. Asian firms can learn from how Sea manages to navigate the increasingly complex and tumultuous global business environment. Sea now faces major challenges in its way of becoming a truly global brand and faces some uncertainty. Nevertheless, Sea’s trajectory and positioning inspire optimism and will continue on its rise to the top.

An additive manufacturing oriented design approach to mechanical assemblies

Sossou, Germain,Demoly, Frederic,Montavon, Ghislain,Gomes, Samuel Society for Computational Design and Engineering 2018 Journal of computational design and engineering Vol.5 No.1

Firstly introduced as a prototyping process, additive manufacturing (AM) is being more and more considered as a fully-edged manufacturing process. The number of AM processes, along with the range of processed materials are expanding. AM has made manufacturable shapes that were too difficult (or even impossible) to manufacture with conventional technologies. This has promoted a shift in engineering design, from conventional design for manufacturing and assembly to design for additive manufacturing (DFAM). Research efforts into the DFAM field have been mostly dedicated to part's design, which is actually a requirement for a better industrial adoption. This has given rise to topologically optimized and/or latticed designs. However, since AM is also capable of manufacturing fully functional assemblies requiring a few or no assembly operations, there is a need for DFAM methodologies tackling product's development more holistically, and which are, therefore, dedicated to assembly design. Considering all the manufacturing issues related to AM of assembly-free mechanisms and available post-processing capabilities, this paper proposes a top-down assembly design methodology for AM in a proactive manner. Such an approach, can be seen as the beginning of a shift from conventional design for assembly (DFA) to a new paradigm. From a product's concept and a selected AM technology, the approach first provides assistance in the definition of the product architecture so that both functionality and successful manufacturing (including post-processing) are ensured. Particularly, build-orientation and downstream processes' characteristics are taken into account early in the design process. Secondly, for the functional flow (energy, material, signal) to be appropriately conveyed by the right amount of matter, the methodology provides guidance into how the components can be designed in a minimalism fashion leveraging the shape complexity afforded by AM. A mechanical assembly as case study is presented to illustrate the DFAM methodology. It is found that clearances and material (be it raw unprocessed material or support structures) within them plays a pivotal role in a successful assembly's design to be additively manufactured. In addition, the methodology for components' design proves to be an efficient alternative to topology optimization. Though, the approach can be extended by considering a strategy for part consolidation and the possibility to manufacture the assemblies with more than one AM process. As regards components' design, considering anisotropy can also improved the approach.

MODERN LANDFILLS ARE SAFE AND SERVE LONG-TERM NEEDS OF THE SOCIETY

( Anne M. Germain ),( N. C. Vasuki ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

The Delaware Solid Waste Authority (DSWA) constructed its first synthetically lined landfill cell in 1980 at its Central Solid Waste Management Center (CSWMC). This cell, Area A, was lined with 0.76 mm poly-vinyl chloride (PVC). This landfill immediately improved solid waste disposal practices and allowed DSWA to safely dispose 2.2 million tonnes of municipal and industrial solid waste discarded between 1980 and 2002. DSWA was also able to use the first two cells construction and operation experience to improve the design of subsequent landfill cells. From the beginning, leachate generated was collected, measured, analyzed and hauled off-site for treatment. Also, groundwater monitoring wells, placed at locations up gradient and down gradient of the landfill cells, were sampled and analyzed, as were selected surface water locations. Similarly, landfill gas measurement and collection occurred as early as 1989. In addition, typical operating procedures included the weighing of all waste brought to the facilities, measurement of cover material and compaction densities. Weather data has been routinely generated from on-site weather stations. Finally, occasional waste characterization is done to determine the basic make-up of the municipal solid waste received at the landfills. Utilizing the data, this paper will discuss (1) improvements in design and operations, (2) long-term performance of the landfill, and (3) costs of landfills. This will include analysis of the leachate and landfill gas quality trend as the landfill ages. In addition, DSWA’s on going research and development program will be discussed.

안전하고 장기간 이용가능한 현대매립지의 방향

( Anne M. Germain ),( N. C. Vasuki ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.2

Delaware Solid Waste Authority (DSWA)는 중앙 폐기물처리센터(CSWMC)에서 1980년 처음으로 인공차수막을 포설한 매립지를 시공했다. 이 매립 셀 (Area A)은, 0.76mm PVC로 차수되었다. 이 매립지는 폐기물 처분장으로 사용되었고, 1980년부터 2002년까지 배출된 220만톤의 폐기물을 처분하기 위해 DSWA에서 허가되었다. DSWA는, 처음 두 개의 매립 셀을, 후속 매립작업을 위한 설계를 개선하는데 필요한 시공과 작업을 위해 이용되었다. 초기에, 발생된 침출수는 수집, 측정, 분석되었고 처리를 위해 외부로 이송되었다. 또한, 인근의 지표수를 채수하여 조사하였고, 매립셀의 상하 구배에 설치된 지하수 감시정에서도 채수되었고 분석되었다. 마찬가지로, 매립가스의 측정 및 포집은 1989년 이전부터 이루어졌다. 게다가, 매립지로 반입되는 모든 폐기물의 계근, 복토재료의 측정, 다짐밀도를 포함한 전형적인 작업이 이루어졌다. 기상자료는 현지 기상대로부터 주기적으로 수집되었다. 마지막으로, 매립지로 반입되는 폐기물의 기본적 성상을 결정하기 위해 수시로 폐기물의 특성을 조사하였다. 이러한 자료를 이용하여, 이 논문은 (1) 설계와 운영의 개선, (2) 매립지의 장기 사용, (3) 매립지의 비용에 대해 토의할 것이다. 매립지의 연령으로서의 매립가스와 침출수의 배출 경향의 분석을 포함할 것이다. 더욱이, 연구와 개발이 진행되고 있는 DSWAs에 대해 논의될 것이다. The Delaware Solid Waste Authority (DSWA) constructed its first synthetically lined landfill cell in 1980 at its Central Solid Waste Management Center (CSWMC). This cell, Area A, was lined with 0.76 mm poly-vinyl chloride (PVC). This landfill immediately improved solid waste disposal practices and allowed DSWA to safely dispose 2.2 million tonnes of municipal and industrial solid waste discarded between 1980 and 2002. DSWA was also able to use the first two cells construction and operation experience to improve the design of subsequent landfill cells. From the beginning, leachate generated was collected, measured, analyzed and hauled off-site for treatment. Also, groundwater monitoring wells, placed at locations up gradient and down gradient of the landfill cells, were sampled and analyzed, as were selected surface water locations. Similarly, landfill gas measurement and collection occurred as early as 1989. In addition, typical operating procedures included the weighing of all waste brought to the facilities, measurement of cover material and compaction densities. Weather data has been routinely generated from on-site weather stations. Finally, occasional waste characterization is done to determine the basic make-up of the municipal solid waste received at the landfills. Utilizing the data, this paper will discuss (1) improvements in design and operations, (2) long-term performance of the landfill, and (3) costs of landfills. This will include analysis of the leachate and landfill gas quality trend as the landfill ages. In addition, DSWA’s on going research and development program will be discussed.

Clothing purchase behavior and the Canadian household life cycle

Anne-Marie Germain,Serge Carrier,Miche`le Beaudoin 한국마케팅과학회 2014 Journal of Global Fashion Marketing Vol.5 No.2

The first intention of this research is to test ifWells and Gubar’smodel (1966) of consumer behavior, based on the life cycle, still explains the Canadian population’s consumption behavior. A second objective, if warranted, is to determine the possibility to segment the Canadian population based on life cycles with the aim of explaining garment/apparel consumption. Using the Survey of Household Spending from Statistics Canada (2009), this article analyses total clothing expenditures and their subcategories of expenses for women and girls, men and boys, and children. Each expense is analyzed using two different data: (1) gross amount of money spent annually and (2) percentage of the category on household total spending. The three hypotheses of this research are validated, confirming (H1) the non-representativeness of Wells and Gubar’s model; (H2) the importance of integrating single households in the life-cycle model since their purchase behaviors are significantly different from those of traditional households; (H3) the possibility to segment based on life-cycle criteria to better understand Canadian realities.

프랑스 공기업의 최근 변화에 관한 보고서

Nicole Maggi-Germain 한국노동연구원 2005 국제노동브리프 Vol.3 No.5

드골과 말로

올리비에제르멩또마 서울대학교 불어문화권연구소 1991 불어문화권연구 Vol.1 No.-

Robust Sliding Mode-H∞ Control Approach for a Class of Nonlinear Systems Affected by Unmatched Uncertainties using a Poly-quadratic Lyapunov Function

Wajdi Saad,Anis Sellami,Germain Garcia 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.6

This paper proposes a robust sliding mode-H∞ control design methodology for a class of nonlinearsystems with unmatched parametric uncertainty and external disturbance. The design procedure combines thehigh robustness of the sliding mode control (SMC) with the H¥ norm performance. First, based on linear matrixinequalities (LMI) technique and multiple Lyapunov functions approach, the sliding surface design problem isformulated as a H¥ state-feedback control for a reduced uncertain nonlinear system with polytopic representation. Then, a sliding mode controller that drives the system states to the sliding surface in finite time and maintains asliding mode is constructed. Finally, a comparative study is done to prove the effectiveness of the results.

Mineralization of semiconductor nanocrystals on peptide-coated bionanotubes and their pH-dependent morphology changes.

Banerjee, Ipsita A,Muniz, Germaine,Lee, Sang-Yup,Matsui, Hiroshi American Scientific Publishers 2007 Journal of nanoscience and nanotechnology Vol.7 No.7

<P>While various mineralizing peptides have been applied to grow metal nanoparticles on bionanotube templates, the semiconductor nanoparticle growth on nanotubes has not extensively been explored yet. In this paper, various semiconductor nanocrystals were grown on the bionanotubes surfaces with controlled sizes. When three synthetic peptides, which recognize and selectively bind Ge, Ti, and Cu ions, respectively, were incorporated on template bionanotube surfaces, highly crystalline and monodisperse Ge, TiO2, and Cu2S nanocrystals were grown on the tube surfaces. The sizes of these nanocrystals could be tuned as a function of pH, and larger semiconductor nanocrystals were grown as the pH of growth solutions was increased. All of these nanocrystals from smaller sizes to larger sizes had the same crystallinity. This peptide-controlled nanocrystal growth technique will be very useful to prepare semiconductor nanowires as building blocks for future microelectronics, whose band gaps can be tuned by the sizes of coated semiconductor nanoparticles via their quantum confinement effect. The novelty of this approach in the electronic device fabrication is that the semiconductor nanocrystal size control can be achieved by controlling peptide configurations via pH change, and this control may tune electronic structures and band gaps of the resulting semiconductor nanowires.</P>