SDINS/GPS in-flight alignment using GPS carrier phase rate

The alignments of the strapdown inertial navigation system (SDINS) utilizing GPS carrier phase rate measurements is introduced. In this paper, a measurement model of GPS carrier phase rate under two antenna configurations is derived in order to be used for the SDINS alignment process. For in-flight alignment, the performance of the proposed SDINS/GPS integration method is analyzed using the covariance analysis and the overall performance is briefly confirmed by the navigation result of a van test. Furthermore, we find that during in-flight alignment the proposed SDINS/GPS integrated system using GPS carrier phase rate measurements can be implemented in real time because the integer ambiguity problem resulting from carrier phase measurements is avoided.     

RT3型岩石高压真三轴仪的研制

本文介绍了新近研制成功的岩石高压真三轴仪的结构特点、功能和试验研究结果。岩石高压真三轴仪能够独立地控制和改变三个主应力,从而可模拟工程岩体和地壳内部的任何应力状态和应力途径,是对卡阿曼(Von.Karman)型普通三轴压缩仪的重大改进。RT3型岩石高压真三轴仪,可施加最大主应力到800MPa,中间主应力200MPa,最小主应力200MPa,并能测定三个主应力方向的应变和声波参数,可供岩石力学基础理论、工程岩体稳定性和地震前兆特性等研究之用。     

A three‐dimensional transmitting boundary formulated in Cartesian co‐ordinate system for the dynamics of non‐axisymmetric foundations

A three‐dimensional transmitting boundary is formulated in the Cartesian co‐ordinate system. It is developed for the dynamic soil–structure interaction problems of arbitrary shape foundations in laterally heterogeneous strata overlying rigid bedrock. Dynamics of a rectangular rigid surface foundation on a homogeneous stratum is analysed by a hybrid approach in which the finite region including foundation is modelled by the conventional finite element method and the surrounding infinite region by the newly developed transmitting boundary. To demonstrate its strength, the present method is applied to a rectangular foundation in a horizontally heterogeneous ground consisting of two distinct regions divided by and welded along a vertical plane. Copyright © 2000 John Wiley & Sons, Ltd.     

Near-surface soil stabilization by enzyme-induced carbonate precipitation for fugitive dust suppression

Acta Geotechnica - To resolve the environmental and sustainability issues from fugitive dust emission and conventional mitigation methods, multiple experiments were conducted to evaluate the...     

乐都地震台前兆观测干扰分析

对乐都地震台2008年1月~2013年10月各前兆测项所受到的环境、人为、观测技术系统和其他干扰进行了分析,调查、了解各类干扰产生的原因及记录特征,有助于及时采取合理、有效的解决措施,提高资料的使用价值和地震前兆异常的识别能力。     

Metabolic plasticity of nitrogen assimilation by Porphyra umbilicalis (Linnaeus) Kützing

The physical stresses associated with emersion have long been considered major factors determining the vertical zonation of intertidal seaweeds.We examined Porphyra umbilicalis(Linnaeus) Kützing thalli from the vertical extremes in elevation of an intertidal population(i.e.upper and lower intertidal zones) to determine whether Porphyra thalli acclimate to different vertical elevations on the shore with different patterns of nitrate uptake and nitrate reductase(NR) and glutamine synthetase(GS) activities in response to different degrees of emersion stress.We found that the nitrate uptake and NR recovery in the emersed tissues took longer in lower intertidal sub-population than in upper intertidal sub-population;and GS activity was also significantly affected by emersion and,interestingly,such an activity was enhanced by emersion of thalli from both upper and lower intertidal zones.These results suggested that intra-population variability in post-emersion recovery of physiological functions such as nutrient uptake and NR activity enables local adaptation and contributes to the wide vertical distribution of P.umbilicalis.The high GS activity during periodic emersion stress may be a protective mechanism enabling P.umbilicalis to assimilate nitrogen quickly when it again becomes available,and may also be an evidence of photorespiration during emersion.     

Selecting suitable sites for mountain ginseng (<Emphasis Type="Italic">Panax ginseng</Emphasis>) cultivation by using geographically weighted logistic regression

With the well-being trends to pursue a healthy life, mountain ginseng (Panax ginseng) is rising as one of the most profitable forest products in South Korea. This study was aimed at evaluating a new methodology for identifying suitable sites for mountain ginseng cultivation in the country. Forest vegetation data were collected from 46 sites and the spatial distribution of all sites was analyzed using GIS data for topographic position, landform, solar radiation, and topographic wetness. The physical and chemical properties of the soil samples, including moisture content, pH, organic matter, total nitrogen, exchangeable cations, available phosphorous, and soil texture, were analyzed. The cultivation suitability at each site was assessed based on the environmental conditions using logistic regression (LR) and geographically weighted logistic regression (GWLR) and the results of both methods were compared. The results show that the areas with northern aspect and higher levels of solar radiation, moisture content, total nitrogen, and sand ratio are more likely to be identified as suitable sites for ginseng cultivation. In contrast to the LR, the spatial modeling with the GWLR results in an increase in the model fitness and indicates that a significant portion of spatial autocorrelation in the data decreases. A higher value of the area under the receiver operating characteristic (ROC) curve presents a better prediction accuracy of site suitability by the GWLR. The geographically weighted coefficient estimates of the model are non-stationary, and reveal that different site suitability is associated with the geographical location of the forest stands. The GWLR increases the accuracy of selecting suitable sites by considering the geographical variations in the characteristics of the cultivation sites.     

Investigation of CO2 behavior and study on design of optimal injection into Gorae-V aquifer

This study presents the Bottom-hole pressure (BHP) behavior with different wettabilities and the optimal design scheme to effectively inject CO₂ into the Gorae-V aquifer. As a result, the injection rate and injectivity were increased as the wettability condition became more water-wet. However, the more wettability condition becomes water-wet, the more the ultimate CO₂ injection volume decreases. When the injectivity was 346 ton/day/Mpa at the Gorae-V aquifer, the aquifer can sustain CO₂ injection at a rate of 2,425 tons per day over this time period. A design for a complete CCS system was developed based on the existing off-shore pipeline in combination with new on-shore CO₂ transport infrastructure, and a pressure of 12.8 MPa is required at the CO₂ source to maintain this injection rate.     

Characteristics of rainfall systems accompanied with Changma front at Chujado in Korea

The rainy season from June to July in the East Asia is called the Changma in Korea, the Meiyu in China, or the Baiu in Japan. The mesoscale convective systems which occur near a front frequently lead to severe weather phenomenon such as localized gust and heavy rainfall. An intensive field experiment was conducted at Chujado (33.95°N, 126.28°E) to find out the characteristics of the precipitating system using information such as the raindrop size distribution, kinematic features during a Changma period between June 21 2007 and July 11 2007. Different characteristics of three identified rainfall cases in a Changma frontal precipitation system occurred from 5 to 6 July in 2007 at Chujado area have been identified. Based on the radar reflectivity and raingage at Chujado, each rainfall system maintained for 7 hours, 4 hours, and 9 hours, respectively. According to the analysis of a total vertical wind shear (TVWS) and a directional vertical wind shear (DVWS), the temperature gradient was the strongest near the surface and both warm and cold advections were occurred in all cases but at different levels. The deep warm advection was related to the longer rainfall lifetime and stronger rainrate, but smaller raindrop size. The unstable atmospheric condition, which has cold advection at the surface and warm advection in higher level, caused the larger size diameter of raindrop. The echo top height of 30 dBZ was around 6 km in the two rainfall systems and around 4 km in the other one. The number concentrations of raindrop has turning point at the drop size of 2 mm in diameter. The stronger (weaker) updraft and downdraft were also related to the decreased number concentration of smaller (larger) size drops and increased that of the larger (smaller) drops.     

Probabilistic assessment of the water quality of bathing beaches on the Taiwanese coast using indicator-based geostatistics with one-dimensional cyclic coordinates

Because Taiwan is a subtropical island, many pleasure beaches are situated on its coast. However, according to long-term monitoring data, fecal contamination at Taiwanese coastal beaches frequently exceeds the U.S. Environmental Protection Agency (EPA) guidelines. To avoid public health hazards, mapping the spatial extent of this contamination is crucial. This study applied indicator kriging (IK) to probabilistically assess the water quality of bathing beaches on the Taiwanese coast. Moreover, because the discontinuity of the traditional Cartesian coordinate established on an island coastline is difficult for geostatistical estimates, this study proposed a novel kriging estimation approach to deal with this problem. First, a one-dimensional (1-D) cyclic coordinate system of the Taiwanese coast was established using primary and secondary coordinates at each beach site. Escherichia coli (E. coli) and enterococci concentrations at coastal beaches were converted into indicator variables according to the U.S. EPA guidelines. IK was then used to spatially model the occurrence probabilities that exceeded the U.S. EPA guidelines for E. coli and enterococci. Finally, the water quality of bathing beaches on the Taiwanese coast was classified on the basis of the estimated probabilities. The study results indicated that bathing on the central western, northeastern, and southeastern Taiwanese coasts poses a potential threat to human health caused by high levels of fecal contamination. Moreover, primary and secondary coordinates established at beach sites were capable of analyzing the spatial variability and kriging estimates of the 1-D cyclic coordinates along the coastline.