• Title/Summary/Keyword: Critical technology elements

Search Result 222, Processing Time 0.025 seconds

Experimental identification of the six DOF C.G.S., Algeria, shaking table system

  • Airouche, Abdelhalim;Bechtoula, Hakim;Aknouche, Hassan;Thoen, Bradford K.;Benouar, Djillali
    • Smart Structures and Systems
    • /
    • v.13 no.1
    • /
    • pp.137-154
    • /
    • 2014
  • Servohydraulic shaking tables are being increasingly used in the field of earthquake engineering. They play a critical role in the advancement of the research state and remain one of the valuable tools for seismic testing. Recently, the National Earthquake Engineering Research Center, CGS, has acquired a 6.1m x 6.1 m shaking table system which has a six degree-of-freedom testing capability. The maximum specimen mass that can be tested on the shaking table is 60 t. This facility is designed specially for testing a complete civil engineering structures, substructures and structural elements up to collapse or ultimate limit states. It can also be used for qualification testing of industrial equipments. The current paper presents the main findings of the experimental shake-down characterization testing of the CGS shaking table. The test program carried out in this study included random white noise and harmonic tests. These tests were performed along each of the six degrees of freedom, three translations and three rotations. This investigation provides fundamental parameters that are required and essential while elaborating a realistic model of the CGS shaking table. Also presented in this paper, is the numerical model of the shaking table that was established and validated.

BGA to CSP to Flip Chip-Manufacturing Issues

  • Caswell, Greg;Partridge, Julian
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.8 no.2
    • /
    • pp.37-42
    • /
    • 2001
  • The BGA package has been the area array package of choice for several years. Recently, the transition has been to finer pitch configurations called Chip Scale Packages (CSP). Several of these package types are available at 0.5 mm pitch. requiring surface mount assemblers to evaluate and optimize various elements of the assembly process. This presentation describes the issues associated with making the transition from BGA to CSP assembly. Areas addressed will include the accuracy of pick and place equipment, printed wiring board lines and spaces, PWB vias, in-circuit test issues, solder paste printing, moisture related factors, rework and reliability. The transition to 0.5 mm pitch requires careful evaluation of the board design, solder paste selection, stencil design and component placement accuracy. At this pitch, ball and board pad diameters can be as small as 0.25 mm and 0.20 mm respectively. Drilled interstitial vias are no longer possible and higher ball count packages require micro-via board technology. The transition to CSP requires careful evaluation of these issues. Normal paste registration and BGA component tolerances can no longer achieve the required process levels and higher accuracy pick and place machines need to be implemented. This presentation will examine the optimization of these critical assembly operations, contrast the challenges at 0.5 mm and also look at the continuation of the process to incorporate smaller pitch flip chip devices.

  • PDF

Novel Packet Switching for Green IP Networks

  • Jo, Seng-Kyoun;Kim, Young-Min;Lee, Hyun-Woo;Kangasharju, Jussi;Mulhauser, Max
    • ETRI Journal
    • /
    • v.39 no.2
    • /
    • pp.275-283
    • /
    • 2017
  • A green technology for reducing energy consumption has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. Here, we propose a novel energy-efficient packet switching method for use in an IP network for reducing unnecessary energy consumption. As a green networking approach, we first classify the network nodes into either header or member nodes. The member nodes then put the routing-related module at layer 3 to sleep under the assumption that the layer in the OSI model can operate independently. The entire set of network nodes is then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using well-known real network topologies and achieved a more energy- efficient performance than that achieved in previous studies.

Splicing and alternative splicing in rice and humans

  • E, Zhiguo;Wang, Lei;Zhou, Jianhua
    • BMB Reports
    • /
    • v.46 no.9
    • /
    • pp.439-447
    • /
    • 2013
  • Rice is a monocot gramineous crop, and one of the most important staple foods. Rice is considered a model species for most gramineous crops. Extensive research on rice has provided critical guidance for other crops, such as maize and wheat. In recent years, climate change and exacerbated soil degradation have resulted in a variety of abiotic stresses, such as greenhouse effects, lower temperatures, drought, floods, soil salinization and heavy metal pollution. As such, there is an extremely high demand for additional research, in order to address these negative factors. Studies have shown that the alternative splicing of many genes in rice is affected by stress conditions, suggesting that manipulation of the alternative splicing of specific genes may be an effective approach for rice to adapt to abiotic stress. With the advancement of microarrays, and more recently, next generation sequencing technology, several studies have shown that more than half of the genes in the rice genome undergo alternative splicing. This mini-review summarizes the latest progress in the research of splicing and alternative splicing in rice, compared to splicing in humans. Furthermore, we discuss how additional studies may change the landscape of investigation of rice functional genomics and genetically improved rice.

A Case Study of Green Ambience through Green Cloud Computing

  • Kumar, Rethina;Kang, Jeong-Jin
    • International journal of advanced smart convergence
    • /
    • v.1 no.2
    • /
    • pp.52-58
    • /
    • 2012
  • Green cloud computing refers to the green ambient benefits that information technology services delivered over the Internet can offer for the society. The green meaning environment friendly and cloud computing is a traditional symbol for the Internet and a type of service provider. Cloud computing has drastically increased the number of datacenters and the energy consumption of data centers and that has become a critical issue which is extremely important in green ambience. These days the cloud data center needs high energy resources that leads to high operational cost and also maximizes CO2 - carbon footprint that pollutes the ambience which is not to be considered as green ambience. So we need to provide a way that leads us to green ambience. Cloud computing for the green ambience should be designed in a way which will utilize less energy resources and to minimize the CO2 -carbon footprint, known as green cloud. In this paper we discuss various elements of Clouds which contributes to minimize the total energy consumption and the carbon emission so as to enable green ambience through green cloud computing.

The Effect of Essential Online Elements on Consumer Purchase Intention: Insights from a Taobao Perspective

  • Feng, Zhou;Lee, Un-Kon
    • Journal of Distribution Science
    • /
    • v.13 no.5
    • /
    • pp.15-22
    • /
    • 2015
  • Purpose - Transparency, seller reputation, and website security are considered to be important factors that influence online customer purchasing decisions in China. This paper empirically examines the relative influence of Taobao.com on customers' online purchasing decisions. Research design, data, and methodology - We perform structural equation analysis, with a sample of 306 observations. The data comes from consumers' real transaction experiences from a specific website. This gives the results of our study more generalizability than studies using subjects who are not asked to engage in real transactions. Results - The results of this study reveal that perceived security and perceived reputation are critical factors affecting consumer trust and perceived transparency is most closely associated with purchase intention. Conclusions - The findings suggest that perceived transparency plays a significant role in increasing online consumer's purchase intention. The knowledge of the relative impacts of these factors and their roles in the customer transaction experience will be useful in developing customized sales strategies. The results of this study reveal that perceived transparency exerts a stronger effect than perceived reputation on consumer purchase intentions.

An Evaluation of the Thermal Supply System Alternatives Using the Multi Attribute Utility Theory (다속성 효용이론을 이용한 열공급시스템 대안 평가)

  • Lee, Deok Ki;Park, Soo Uk;Hong, Jong Chul
    • Environmental and Resource Economics Review
    • /
    • v.15 no.3
    • /
    • pp.451-477
    • /
    • 2006
  • At the "Dissemination Stage", the newly configured technical design is compared with other alternatives to come up with the most desirable selection. The assessment conducted at this stage is not a simple procedure. It goes through the complex evaluation process in which various elements including economic effects and technical characteristics are considered. The reason for taking such a complex procedure is that the assessment, selection and application of the desirable technical alternative is critical for the company's competitive edge in every field of industrial sectors, thus influencing its survival and continuous growth. This study reviews the MAUT method for assessing technical alternatives of the thermal supply system design. And, to show the practical validity of the MAUT method, it is applied to the evaluation of thermal supply system alternatives in the field of energy supply system technology.

  • PDF

Cadmium-Induced Gene Expression is Regulated by MTF-1, a Key Metal- Responsive Transcription Factor

  • Gupta, Ronojoy-Sen;Ahnn, Joohong
    • Animal cells and systems
    • /
    • v.7 no.3
    • /
    • pp.173-186
    • /
    • 2003
  • The transition metal cadmium is a serious occupational and environmental toxin. To inhibit cadmium-induced damage, cells respond by increasing the expression of genes that encode stress-responsive proteins. The metal-regulatory transcription factor 1 (MTF-1) is a key regulator of heavy-metal induced transcription of metallothionein-I and II and other genes in mammals and other metazoans. Transcriptional activation of genes by MTF-1 is mediated through binding to metal-responsive elements in the target gene promoters. Phosphorylation of MTF-1 plays a critical role in the cadmium-inducible transcriptional activation of metallothionein and other responses. Studies using inhibitors indicate that multiple kinases and signal transduction cascades, including those mediated by protein kinase C, tyrosine kinase and casein kinase II, are essential for cadmium-mediated transcriptional activation. In addition, calcium signaling is also involved in regulating metal-activated transcription. In several species, cadmium induces heat shock genes. Recently much progress has been made in elucidating the cellular machinery that regulates this metal-inducible gene expression. This review summarizes these recent advances in understanding the role of some known cadmium-responsive genes and the molecular mechanisms that activate metal-responsive transcription factor, MTF-1.

BGA to CSP to Flip Chip - Manufacturing Issues

  • Caswell, Greg;Partridge, Julian
    • Proceedings of the International Microelectronics And Packaging Society Conference
    • /
    • 2001.04a
    • /
    • pp.27-34
    • /
    • 2001
  • The BGA Package has been the area array package of choice for several rears. Recently, the transition has been to finer pitch configuration called Chip Scale Packages (CSP). Several of these package types are available at 0.5 mm pitch, requiring surface mount assemblers to evaluate and optimize various elements of the assembly process. This presentation describes the issues associated with making the transition from BGA to CSP assembly. Areas addressed will include the accuracy of pick and piece equipment, printed wiring board lines and spaces, PWB vias, in-circuit test issues, solder paste printing, moisture related factors, rework and reliability. The transition to 0.5 mm pitch requires careful evaluation of the board design, solder paste selection, stencil design and component placement accuracy. At this pitch, ball and board pad diameters can be as small as 0.25 mm and 0.20 mm respectively. Drilled interstitial vias are no longer possible and higher ball count packages require micro-via board technology. The transition to CSP requires careful evaluation of these issues. Normal paste registration and BGA component tolerances can no longer achieve the required process levels and higher accuracy pick and place machines need to be implemented. This presentation will examine the optimization of these critical assembly operations, contrast the challenges at 0.5 mm and also look at the continuation of the process to incorporate smaller pitch flip chip devices.

  • PDF

Investigation on Suppression of Nickel-Silicide Formation By Fluorocarbon Reactive Ion Etch (RIE) and Plasma-Enhanced Deposition

  • Kim, Hyun Woo;Sun, Min-Chul;Lee, Jung Han;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.13 no.1
    • /
    • pp.22-27
    • /
    • 2013
  • Detailed study on how the plasma process during the sidewall spacer formation suppresses the formation of silicide is done. In non-patterned wafer test, it is found that both fluorocarbon reactive ion etch (RIE) and TEOS plasma-enhanced deposition processes modify the Si surface so that the silicide reaction is chemically inhibited or suppressed. In order to investigate the cause of the chemical modification, we analyze the elements on the silicon surface through Auger Electron Spectroscopy (AES). From the AES result, it is found that the carbon induces chemical modification which blocks the reaction between silicon and nickel. Thus, protecting the surface from the carbon-containing plasma process prior to nickel deposition appears critical in successful silicide formation.