Geomatics and Information Science of Wuhan University,Vol 42,No. 08
【Abstract】 In recent three decades, the development of Global Positioning System (GPS) highly extends its application fields, one of which is to use GPS monitor water vapor in the troposphere. When slant wet delays of GPS signals are treated as tomography observations, they can be used to retrieve three-dimensional wet refractivity fields of the troposphere. However, due to the uneven distribution of the signal rays and flat orography of the network in Hong Kong, the tomography observation equations are ill-posed, so some constraints are usually added to determine the unique tomography solution. Since the water vapor changes rapidly in the vertical direction, appropriate vertical constraints play an important role in retrieving the accurate vertical structure of the wet refractivity fields. By investigating the vertical distribution characteristics of the wet refractivity in the atmosphere in Hong Kong area, we find that the Gaussian function can well express the relationship between the wet refractivity and the height. The tomographic experiments using the data from Hong Kong Satellite Positioning Reference Station Network show that the tomographic solution using Gaussian function to establish vertical constraints gets a better agreement with the radiosonde data and the European Centre for Medium-Range Weather Forecasts (ECMWF) data when compared with the solution obtained by establishing vertical constraints by using the exponential function. The improvements with respect to standard deviation are 3.8 mm/km in the whole troposphere and 4.7 mm/km in the lower troposphere. The experiments also show that using good a priori wet refractivity from other meteorological data sources, like radiosonde, can help obtain good tomographic solutions.
Economic function evolution of Hong Kong in the process of opening up to the outside world (1978–2007)
Researches in Chinese Economic History,No. 03
【Abstract】 Hong Kong has been playing an important window and bridge role in the history of China’s opening up to the outside world. Studying and summarizing the evolution history of Hong Kong’s economic function in the process of opening up strategy is of great significance to deepening understanding of the process of China’s economic history. In the period of export-oriented development strategy (from 1978 to 1997), Hong Kong’s economic effects mainly manifest in that it is the main window for the China’s mainland to access the international market, the most important source of external direct investment, the main bridge for the China’s mainland to undertake international industrial transfer and the introducer of market mechanism and management experience, and Hong Kong’s simultaneous transformation into a service economy and so on. In the period of opening economic development strategy (from 1998 to 2007), Hong Kong’s economic function after its return to China has transformed from traditional intermediary function to platform economy and global city function. Service trade and service investment has accelerated, undertaking the roles such as two-way service platform of “bringing in” and “going global,” buffer zone for the opening of national finance and test field for internationalization of RMB, reference system for improving the market economy system and converter for docking international rules and so on. The economic relationship between Hong Kong and the China’s mainland has shifted from one-way advantage of Hong Kong to two-way interaction.
Precarious work and labor market segmentation: a comparative study on Chinese mainland and China’s Hong Kong
Sociological Studies,Vol 33,No. 05
【Abstract】 The world-wide growth of precarious work has created a new type of labor market segmentation, and calls for cross-society comparison study. Chinese mainland and China’s Hong Kong facilitate such a comparison, since the two societies operated in quite different socioeconomic institutions have experienced the same change of employment relations. By analyzing two representative and comparable survey data, this research has found similarity as well as discrepancy regarding to occurrence and segmentation of precarious work in the two labor markets. In general, precarious work distributes in more economic sectors in Chinese mainland than it does in China’s Hong Kong, while it engenders less segmentation in the former in the labor market. This is closely related to the institutional and practical differences in labor market regulation of the two societies.