Application of the context map : modeling the Rational Unified Process and Rational ClearQuest

As much as each of us would like to get up every day with only a few things to focus on, the competitive world we live in rarely allows such a luxury. Balancing complexity with simplicity is an art, and it is one that we must master. In today's competitive information technology world, the pressure is on to stay in front of your competition. The value and visibility of your development projects compel you to reduce time-to-market without sacrificing quality and with lower cost. There are so many high level representing technologies for information system and software engineering. With so many representing technologies, how do we choose the one that will help us get ahead of the curve? An advanced, powerful, easy to learn and lower cost technology named Context Map is introduced as a common modeling language. The purpose of this project is to illustrate that Context Map is not only a methodology and formalized notation for representing the knowledge, but also it's a powerful tool itself which can be used directly to manipulate the formatted knowledge. The functionality and attributes of Context Maps are demonstrated by modeling of Unified Process Concepts, Rational Unified Process framework and Rational ClearQuest tool set

A one-dimensional extremely covalent material: monatomic carbon linear chain

Polyyne and cumulene of infinite length as the typical covalent one-dimensional (1D) monatomic linear chains of carbon have been demonstrated to be metallic and semiconductor (Eg = 1.859 eV), respectively, by first-principles calculations. Comparing with single-walled carbon nanotubes, the densities are evidently low and the thermodynamic properties are similar below room temperature but much different at the high temperature range. Polyyne possesses a Young's modulus as high as 1.304 TPa, which means it is even much stiffer than carbon nanotubes and to be the superlative strong 1D material along the axial direction. The Young's modulus of cumulene is estimated to be 760.78 GPa. In addition, polyyne is predicted to be as a one-dimensional electronic material with very high mobility

13C-Metabolic Flux Analysis Reveals the Metabolic Flux Redistribution for Enhanced Production of Poly-γ-Glutamic Acid in dlt Over-Expressed Bacillus licheniformis

Poly-γ-glutamic acid (γ-PGA) is an anionic polymer with various applications. Teichoic acid (TA) is a special component of cell wall in gram-positive bacteria, and its D-alanylation modification can change the net negative charge of cell surface, autolysin activity and cationic binding efficiency, and might further affect metabolic production. In this research, four genes (dltA, dltB, dltC, and dltD) of dlt operon were, respectively, deleted and overexpressed in the γ-PGA producing strain Bacillus licheniformis WX-02. Our results implied that overexpression of these genes could all significantly increase γ-PGA synthetic capabilities, among these strains, the dltB overexpression strain WX-02/pHY-dltB owned the highest γ-PGA yield (2.54 g/L), which was 93.42% higher than that of the control strain WX-02/pHY300 (1.31 g/L). While, the gene deletion strains produced lower γ-PGA titers. Furthermore, 13C-Metabolic flux analysis was conducted to investigate the influence of dltB overexpression on metabolic flux redistribution during γ-PGA synthesis. The simulation data demonstrated that fluxes of pentose phosphate pathway and tricarboxylic acid cycle in WX-02/pHY-dltB were 36.41 and 19.18 mmol/g DCW/h, increased by 7.82 and 38.38% compared to WX-02/pHY300 (33.77 and 13.86 mmol/g DCW/h), respectively. The synthetic capabilities of ATP and NADPH were also increased slightly. Meanwhile, the fluxes of glycolytic and by-product synthetic pathways were all reduced in WX-02/pHY-dltB. All these above phenomenons were beneficial for γ-PGA synthesis. Collectively, this study clarified that overexpression of dltB strengthened the fluxes of PPP pathway, TCA cycle and energy metabolism for γ-PGA synthesis, and provided an effective strategy for enhanced production of γ-PGA

Mapping Impervious Surface Expansion using Medium-resolution Satellite Image Time Series: A Case Study in the Yangtze River Delta, China

Cities have been expanding rapidly worldwide, especially over the past few decades. Mapping the dynamic expansion of impervious surface in both space and time is essential for an improved understanding of the urbanization process, land-cover and land-use change, and their impacts on the environment. Landsat and other medium-resolution satellites provide the necessary spatial details and temporal frequency for mapping impervious surface expansion over the past four decades. Since the US Geological Survey opened the historical record of the Landsat image archive for free access in 2008, the decades-old bottleneck of data limitation has gone. Remote-sensing scientists are now rich with data, and the challenge is how to make best use of this precious resource. In this article, we develop an efficient algorithm to map the continuous expansion of impervious surface using a time series of four decades of medium-resolution satellite images. The algorithm is based on a supervised classification of the time-series image stack using a decision tree. Each imerpervious class represents urbanization starting in a different image. The algorithm also allows us to remove inconsistent training samples because impervious expansion is not reversible during the study period. The objective is to extract a time series of complete and consistent impervious surface maps from a corresponding times series of images collected from multiple sensors, and with a minimal amount of image preprocessing effort. The approach was tested in the lower Yangtze River Delta region, one of the fastest urban growth areas in China. Results from nearly four decades of medium-resolution satellite data from the Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper plus (ETM+) and China-Brazil Earth Resources Satellite (CBERS) show a consistent urbanization process that is consistent with economic development plans and policies. The time-series impervious spatial extent maps derived from this study agree well with an existing urban extent polygon data set that was previously developed independently. The overall mapping accuracy was estimated at about 92.5% with 3% commission error and 12% omission error for the impervious type from all images regardless of image quality and initial spatial resolution