Sector Capacity Estimation Based on Differentiated Routes and Busy Levels

Sector capacity estimation plays an important role in applied research of airspace management.Previous researches manifest that sector capacity should be influenced by its standard flow,or routes in that sector.However,if air traffic controller(ATCO)workload busy levels(level of proactivity of an ATCO)are ignored,the estimated sector capacity may not be accurate.There is a need to compare the estimated sector capacity with and without busy levels consideration,both with differentiated routes consideration.This paper proposes a method for sector capacity estimation based on ATCO workload considering differentiated routes and busy levels.Firstly,the main routes in the sector are identified,and for each route,the ATCO workload per flight is determined.Secondly,the workload for each route at three busy levels is determined.Regression analysis is then applied to determine the relationship between workload and the number of flights(with and without considering busy levels)in 15 min and 1h time slices.Sector capacity is then determined on the basis of a specified workload threshold,for the two cases with and without considering busy levels.Comparing the two scenarios and following validation by ATCO survey,it is found that capacity estimation considering busy levels is a more realistic and accurate approach.The validated capacity values for the Zhengzhou approach(ZHCC AP)airspace sector accounting for the busy levels were determined accurately as 10 and 33 flights for the 15 min and 1h slices,respectively.The corresponding results without considering busy levels were 12 and 41 flights for the 15 min and 1h time slices,respectively.

Land subsidence monitoring by D-InSAR technique

Nowadays, the researches of using Differential Interferometric Synthetic Aperture Radar (D-InSAR) tech- nique to monitor the land subsidence are mainly on how to qualitatively analyze the subsidence areas and values, but the analysis of subsidence process and mechanism are insufficient. In order to resolve these problems, 6 scenes of ERS1/2 images captured during 1995 and 2000 in a certain place of Jiangsu province were selected to obtain the subsidence and velocities in three time segments by ''two-pass'' D- InSAR method. Then the relationships among distributions of pumping wells, exploitation quantity of groundwater, and confined water levels were studied and the subsidence mechanism was systematically analyzed. The results show that using D-InSAR technique to monitor the deformation of large area can obtain high accuracies, the disadvantages of classical observation methods can be remedied and there is a linear relationship among the velocities of land subsidence, the water level and the exploitation quantity.

DIAGNOSTIC VALUE OF SERUM INSULIN- LIKE GROWTH FACTOR BINDING PROTEIN- 3 IN CHILDREN WITH OR WITHOUT GROWTH HORMONE DEFICIENCY

OBJECTIVE: To study the value of serum insulin-like growth factor binding protein-3 (IGFBP-3) levels in differential diagnosis of growth hormone deficiency (GHD). METHODS: To measure serum IGFBP-3 levels by RIA in normal children and adolescents, GHD children and short-stature children without GHD. RESULTS: Serum level of IGFBP-3 in 129 children with untreated GHD and with no pubertal development was 1.6 +/- 0.9 mg/L, which was less than that in normal group of the same age, but overlapped with the normal children in Tanner stage I. After six-month treatment with recombinant human growth hormone (rhGH), serum level of IGFBP-3 in 59 GHD significantly increased from 1.3 +/- 0.7 mg/L to 2.7 +/- 0.9 mg/L, accompanied by an increase of body heights, growth velocities and serum level of IGF-1. Serum level of IGFBP-3 in 55 short-stature children without GHD was 3.3 +/- 2.2 mg/L, which was not significantly different from that in normal group. CONCLUSION: Serum IGFBP-3 level can reflect the status of GH secretion in children with GHD and is a useful marker for differential diagnosis of GHD.