Defect Contour Detection of Complex Structural Chips

In the manufacture of chips, it is important to detect defects to assess whether the chip is potentially damageable that could cause unnecessary cost. Most assessment rules are set in light of characteristics determined by defect contours, such as area and range. However, conventional image process methods seldom show a satisfactory performance on chips with complex structures because they are difficult to distinguish defect contours from edges of structures. To solve this issue, this study proposes a method based on region segmentation search. The positions of structures in the image are calculated by edge matching to obtain the number of structure layers in each pixel. Regions whose pixels have the same number are divided into subregions which are coded by the two-pass algorithm. The edges in each subregion are then extracted by the Canny operator to construct edge information of the whole image. Interpolation is used to correct incomplete defect edges according to their endpoints. The remaining interference contours are eliminated on the basis of their shapes. A study of a certain kind of chips is presented. Different illumination situations were simulated to verify the robustness of the proposed method. Most bubbles in the images were detected successfully with their contours coded accurately. Because of this, more than 92% of assessment results of chips were identical to the ones in reality engineering, which proves that the method proposed by this study can efficiently detect the defect contours and improve the ability obviously relative to the current approaches

Ecosystem carbon stock loss after a mega earthquake

Earthquake-induced geohazards, in particular landslides and debris flows, have the ability to disturb large stocks of organic carbon. Even a slight change in these stocks of organic carbon could affect atmospheric CO2 concentrations. Yet, the fate of ecosystem carbon delivery caused by a mega-earthquake over a short timescale is not well understood. In this study, a methodology is proposed to study the impact of earthquake-triggered landslides and post-seismic debris flows on ecosystem carbon (C). Pairs-plots were established on undisturbed areas, coseismic landslides or debris flow in one of the most representative catchments, in the 2008 Wenchuan earthquake hit regions. Results showed that coseismic landslides greatly reduced vegetation C stock from 34.48 to 6.85 and soil C stock from 96.38 to 6.77 , thereby leading to 89.6% reduction for total ecosystem C stock. Similarly, debris flow deposit led to a reduction of 97.8% of ecosystem C stock. Overall, it is estimated that there was a loss of 0. C across the study area, indicating a large amount of carbon change after the mega-earthquake. This study has an important implication for the role of mega-earthquake on regional ecosystem C storage and fills our knowledge gaps of the impact of ecosystem C cycle along with earthquake-induced geohazard chains

Asynchronized erosion effects due to climate and human activities on the central Chinese Loess Plateau during the Anthropocene and its implications for future soil and water management

Variations and regional differences in land surface processes during the Anthropocene have directly impacted local economic development and social stability. Nevertheless, little is known about the historical erosion effects and human-environment interactions at annual and decadal scales on the central Chinese Loess Plateau (CLP) over the past 200 years, when human activities and annual sediment discharge both reached historical peaks. Located in the northcentral hilly-gully and southcentral plateau-gully regions, respectively, the Jingbian and Heshui landslide-dammed reservoirs were ideal settings to reconstruct the erosion flux and precipitation over A.D. 1850-2000 due to vertical stacking of interannual couplets. During this period, the mean annual specific sediment yield reached 1.17 x 10(4) t/(km(2) a) in the Jingbian catchment (precipitation threshold of 30 mm), while it reached 1.13 x 10(4) t/(km(2) a) in the Heshui catchment (precipitation threshold of 40 mm) according to sediment yield with frustum and extrapolation of historical precipitation. Interannual El Nino-Southern Oscillation (ENSO) events were deemed a primary climatic factor inducing soil erosion over the central CLP. This should remind decision-makers that it is necessary to prevent large-scale floods and severe erosion before future ENSO events. Changes in population, policies, and human activities also affected land surface processes on the central CLP during 1850-2000. In addition, the results revealed that abandoned farmlands in the southcentral regions with 600 mm and more precipitation had a strong ecological resilience, while this was weak in the northcentral drier region. These findings imply that future ecological restoration of the central CLP should consider the ecological resilience of farmlands that have been recently abandoned due to urbanization. These novel results provide new insights into regional soil and water management under China's development agenda of 'Ecological Conservation and High-quality Development of the Yellow River Basin'