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ObjectiveTo investigate the infestation and disposal of bedbugs in Shanghai， and provide scientific evidence for comprehensive prevention and control of bedbugs.MethodsA questionnaire survey was conducted in the pest control operations （PCOs） of Shanghai Association for Health Promotion to investigate the infestation and disposal of bedbugs. The questionnaire included basic information of the unit， bedbug disposal experience， type of environment of bedbug infestation， main disposal site， main treatment method， main drug and formulation， and evaluation of the disposal. Chi-square test was used for comparison between groups.ResultsOf the 116 PCOs， 78 （67.24%） had conducted bedbug disposal， and 29.49% had conducted the disposal no less than 5 times in the past three years. The main types of environment of bedbug infestation were dormitories （46.96%）， hotels （18.78%）， and households （20.44%）. Additionally， bedbug infestation was found in nursing homes， prisons and detention centers， and transport vehicles. Bed frame/bed board/mattress （32.42%） was the main site of bedbug infestation， followed by mat （19.63%）. Chemical spraying was the most common method for bedbug disposal （98.72%）， followed by high-temperature steam （11.54%）. The main drug used in chemical spraying were pyrethroids （69.23%）， nicotinoids （60.26%） and organophosphorus （42.31%）， for which the main formulation were suspended insecticides （55.13%）， followed by wettable powders （43.59%） and emulsifiers （43.59%）. Furthermore， 89.74% of the PCOs performed the assessment after disposal， in which the control effect was generally satisfactory.ConclusionBedbug infestation is relatively common in Shanghai. Dormitories， hotels and households are places where bedbug infestation is more likely to occur. Bed frame， bed board and mattress are the most vulnerable sites to bedbug infestation. Combination of physical and chemical methods should be used for disposal of bedbug infestation.

As one of the key techniques used in the perception layer of the Industrial Internet of Things (IIoT), radio frequency identification (RFID) has been widely applied for object tracing, smart warehouse management, product line monitoring, etc. In most applications, conveyor belts are prevalently implemented to accelerate the sorting efficiency for goods management. However, in such a system, tags quickly go through the reader's reading range resulting in constant changing of the tag set and limited participating time of moving tags. As a result, it poses more challenges to the tag identification problem in mobile systems than in traditional static applications. In this work, a novel admission-control-based dynamic query tree (ACDQT) protocol is proposed for fast-moving tag identification. In ACDQT, two main strategies are developed, i.e., multi-round admission control (MRAC) and dynamic query tree recognition (DQTR). In MRAC, the reading process of multiple rounds is analyzed, and the number of admitted tags in each round is optimized. Thus, the tag lost ratio is guaranteed, and the identification process can be effectively accelerated. In DQTR, colliding tags are grouped into multiple subsets with the help of consecutive colliding bits in tag responses. By constructing a dynamic query tree, the number of collision slots is greatly reduced, and the identification efficiency in a single round is improved significantly. With MRAC and DQTR, ACDQT can support higher tag flow rate in mobile systems than existing works. Both theoretical analyses and simulation results are presented to demonstrate the effectiveness of ACDQT. [ABSTRACT FROM AUTHOR]

In passive radio frequency identification (RFID) systems, the capture effect may occur that the reader is possible to successfully decode the strongest signal when multiple tags reply simultaneously. In this situation, the weaker signals will be covered resulting in a tag hidden problem which greatly affects the system performance. To solve the problem, a bit-detecting M-ary tree (BMT) protocol was proposed. First, a bit-detecting tag number estimation method was proposed to estimate the number of tags and group them with a few slots. Next, an M-ary tree protocol was developed to eliminate all the idle slots and identify tags quickly. At the same time, a hash muting strategy was given to mute the identified tags and label the hidden ones with small communication cost. Both theoretic analysis and simulation results demonstrate that BMT can effectively reduce the identification delay by at least 15%. [ABSTRACT FROM AUTHOR]