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Field survey is a very important step in the process of land consolidation and rehabilitation. Traditional methods of field survey take much time and effort and it is difficult to locate facilities of projects, to measure area or length and to spot and record problems quickly and accurately. A global positioning system (GPS)-based field survey system is introduced. Firstly, the framework of the system is described. Secondly, the key technologies are shown. including data preparation, locating accurately, coordinate transformation, field measuring and field editing. Finally, further applications are discussed. The major result of this study is a GPS-based field survey system which will promote the application of GPS-personal digital assistant (PDA) technology in the field of land consolidation and rehabilitation, creating an effective method for improving field survey. In this paper, the authors analyse the demands of field survey and introduce the basic ideas of system design and the major functions of the system. This paper also focuses on the implementation of key technologies which are expressed by unified modelling language (UML) figures and tables, such as data preparation, field positioning, coordinate registration, field measurement and recording. It has been shown that the GPS-based field survey system can greatly enhance the quality and efficiency of field survey, help solve many technical problems and make field survey more straightforward. Widespread adoption of GPS-PDA technology is important to improving land and resource management. [ABSTRACT FROM AUTHOR]

Objective: To provide a clinical reference by comparing the conventional 226 Hz tympanometry with 1000 Hz tympanometry in two groups of young children with otitis media effusion evidenced by CT scan., Method: One hundred and seventy-seven young children (226 ears), from 1 to 60 months, with otitis media effusion were involved in this study. They were divided into six groups by age: 0-6 months group, 6-12 months group, 12-18 months group, 18-24 months group, 24-36 months group, 36-60 months group. They were tested with tympanometry of 2 probe-tones of 226 and 1 000 Hz. Type A tympanogram was defined as a normal middle ear function in 226 Hz and single-or double-peak in 1 000 Hz tympanometry. One hundred and fifty-eight normal young children (266 ears) were selected as control group. The results were analysed with Chi square test. Receiver operator characteristic (ROC) analysis was performed to evaluate the two methods., Result: In the young children with otitis media effusion, the detection rate of 226 Hz tympanogram in six groups was 21.1%, 35.2%, 46.9%, 42%, 62.5% and 68% respectively, while 94.7%, 98.1%, 96.9%, 91.2%, 95.8% and 88% respectively in 1 000 Hz tympanogram. In the young children with normal middle ear function, the detection rate of 226 Hz tympanogram in six groups was 95.1%, 88.6%, 85.1%, 93.3%, 88.5% and 93.5%, while 87.8%, 94.3%, 89.4%, 95.6%, 94.2% and 97.8% respectively in 1 000 Hz tympanogram. The detection rate was significantly different between 226 and 1 000 Hz tympanogram in the young children under 36-month old., Conclusion: A single-or double-peak 1000 Hz tympanometric patterns as normal criteria was a simple way to evaluate young children s' middle ear function. 1 000 Hz tympanometry should be given priority to the children within 36-month old in detection middle ear function,the 226 and 1 000 Hz tympanometry should be done at the same time within 36-60 months old.

Objective: The aim of this study is to evaluate the development of auditory performance and speech intelligibility within the first year after hearing aid fitting in children with moderate or severe hearing loss, investigate the effects of hearing level on auditory performance and speech intelligibility and provide a clinical database for their hearing and speech habilitation., Method: Twenty-nine children participated in this study, ranging in age at hearing aid fitting from 3 to 8 years old with a mean of 5. 6 years old. 19 were boys and 10 were girls. According to their hearing level, they were divided into two groups. 14 children were in group of moderate hearing loss (41-60 dB HL). 15 children were in group of severe hearing loss (61-80 dB HL). The categories of auditory performance (CAP) and speech intelligibility rating (SIR) were used to evaluate their auditory performance and speech intelligibility. The evaluation was performed before hearing aid fitting and 1, 3, 6, 9, 12 months after fitting., Result: There was significant difference in mean score of CAP between group of moderate hearing loss and severe hearing loss before hearing aid fitting (P < 0.05). However, no significant differences were observed between these two groups at 1, 3, 6, 9, 12 months after fitting (P > 0.05). There was also significant difference in mean score of SIR between group of moderate hearing loss and severe hearing loss before hearing aid fitting (P < 0.05). How ever, no significant differences were also observed between these two groups at 1, 3, 6, 9, 12 months after fitting (P > 0.05). The mean scores of CAP for group of moderate hearing loss at 6, 9, 12 months after fitting were significantly superior in comparison with the score before hearing aid fitting (P < 0.05). The mean scores of SIR for group of moderate hearing loss at 6, 9, 12 months after fitting were significantly superior in comparison with the score before hearing aid fitting (P < 0.05); the mean score at 12 months after fitting was also significantly superior in comparison with the score at 1 month after fitting (P < 0.05). The mean scores of CAP for group of severe hearing loss at 3, 6, 9, 12 months after fitting were significantly superior in comparison with the score before hearing aid fitting (P < 0.05); the mean scores at 9,12 months after fitting were significantly superior in comparison with the score at 1 month after fitting (P < 0.05). The mean scores of SIR for group of severe hearing loss at 3, 6, 9, 12 months after fitting were significantly superior in comparison with the score before hearing aid fitting (P < 0.05); the mean scores at 6, 9, 12 months after fitting were also significantly superior in comparison with the score at 1 month after fitting (P < 0.05)., Conclusion: Auditory performance and speech intelligibility in children with moderate or severe hearing loss improved significantly within the first year after hearing aid fitting. The development followed different trajectory.