针对普适室内外场景持续感知面临的低功耗、复杂动态环境、异构使用模式带来的挑战,提出了一种轻量级的基于支持向量机多分类器的高精度、低功耗室内外场景检测算法。该算法使用智能手机集成的各种传感器(可见光传感器、磁传感器、加速...针对普适室内外场景持续感知面临的低功耗、复杂动态环境、异构使用模式带来的挑战,提出了一种轻量级的基于支持向量机多分类器的高精度、低功耗室内外场景检测算法。该算法使用智能手机集成的各种传感器(可见光传感器、磁传感器、加速度传感器、陀螺仪传感器和气压传感器),在挖掘分析各种传感器在室内外场景的不同特征,以及人们在室内外场景的行为差异基础上,根据时间和气象条件设计多个支持向量机分类器,对复杂室内外场景进行识别。实验结果表明,基于支持向量机多分类器的室内外场景检测算法具有较好的普适性,可获得95%以上的室内外判定准确率,平均功耗小于5 m W。展开更多
Indoor localization is very critical for medical care applications, e.g., the patient localization or tracking inside the building of the hospital. Traditional Radio Frequency Identification(RFID) technologies are ver...Indoor localization is very critical for medical care applications, e.g., the patient localization or tracking inside the building of the hospital. Traditional Radio Frequency Identification(RFID) technologies are very popular in this area since their cost is very low. In such technologies, each tag acts as the transmitter and the Radio Signal Strength Indicator(RSSI) information is measured from the readers. However, RSSI information suffers severely from the multi- path phenomenon. As a result, if in a very large area, the localization accuracy will be affected seriously. In order to solve this problem, we introduce Wireless Sensor Networks(WSNs) with only a few nodes, each of which acts as both transmitter and receiver. In such networks, the change of signal strength(referred as dynamic of RSSI) is leveraged to select a cluster of reference tags as candidates. Then the fi nal target location is estimated by using the RSSI relationships between the target tag and candidate reference tags. Thus, the localization accuracy and scalability are able to be improved. We proposed two algorithms, SA-LANDMARC, and COCKTAIL. Experiments show that the localization accuracy of the two algorithms can reach 0.7m and 0.45 m, respectively. Compared to most traditional Radio Frequency(RF)-based approaches, the localization accuracy is improved at least 50%.展开更多
In this paper,transient electromagnetic method was used to carry out the feasibility study on the detection and recognition of chamber blasting misfire.Firstly,an electromagnetic background field was established in th...In this paper,transient electromagnetic method was used to carry out the feasibility study on the detection and recognition of chamber blasting misfire.Firstly,an electromagnetic background field was established in the test;secondly,a benign conductor was preset in the chamber,and then the background field was eliminated after the electromagnetic field was measured;thirdly,the transient electromagnetic field was measured again after blasting;at last,the chamber blasting misfire was detected and recognized by comparing the change of eddy current field of the preset benign conductor before and after blasting.The test results showed that:When the buried depth of aluminum box target was no more than 30 m,transient electromagnetic method can clearly identify the position of the aluminum box;when the buried depth of aluminum box was more than30 m,the buried depth and position of the aluminum box was not sure due to the unknown level of secondary eddy current field generated by aluminum box.展开更多
文摘针对普适室内外场景持续感知面临的低功耗、复杂动态环境、异构使用模式带来的挑战,提出了一种轻量级的基于支持向量机多分类器的高精度、低功耗室内外场景检测算法。该算法使用智能手机集成的各种传感器(可见光传感器、磁传感器、加速度传感器、陀螺仪传感器和气压传感器),在挖掘分析各种传感器在室内外场景的不同特征,以及人们在室内外场景的行为差异基础上,根据时间和气象条件设计多个支持向量机分类器,对复杂室内外场景进行识别。实验结果表明,基于支持向量机多分类器的室内外场景检测算法具有较好的普适性,可获得95%以上的室内外判定准确率,平均功耗小于5 m W。
基金supported in part by China NSFC Grant 61202377 and 61170076the Guangdong Natural Science Foundation under Grant 2014A030313553+2 种基金the China National High Technology Research and Development Program 863, under Grant 2015AA015305Joint Funds of the National Natural Science Foundation of China under Grant U1301252Guangdong Province Key Laboratory Project under grant 2012A061400024
文摘Indoor localization is very critical for medical care applications, e.g., the patient localization or tracking inside the building of the hospital. Traditional Radio Frequency Identification(RFID) technologies are very popular in this area since their cost is very low. In such technologies, each tag acts as the transmitter and the Radio Signal Strength Indicator(RSSI) information is measured from the readers. However, RSSI information suffers severely from the multi- path phenomenon. As a result, if in a very large area, the localization accuracy will be affected seriously. In order to solve this problem, we introduce Wireless Sensor Networks(WSNs) with only a few nodes, each of which acts as both transmitter and receiver. In such networks, the change of signal strength(referred as dynamic of RSSI) is leveraged to select a cluster of reference tags as candidates. Then the fi nal target location is estimated by using the RSSI relationships between the target tag and candidate reference tags. Thus, the localization accuracy and scalability are able to be improved. We proposed two algorithms, SA-LANDMARC, and COCKTAIL. Experiments show that the localization accuracy of the two algorithms can reach 0.7m and 0.45 m, respectively. Compared to most traditional Radio Frequency(RF)-based approaches, the localization accuracy is improved at least 50%.
文摘In this paper,transient electromagnetic method was used to carry out the feasibility study on the detection and recognition of chamber blasting misfire.Firstly,an electromagnetic background field was established in the test;secondly,a benign conductor was preset in the chamber,and then the background field was eliminated after the electromagnetic field was measured;thirdly,the transient electromagnetic field was measured again after blasting;at last,the chamber blasting misfire was detected and recognized by comparing the change of eddy current field of the preset benign conductor before and after blasting.The test results showed that:When the buried depth of aluminum box target was no more than 30 m,transient electromagnetic method can clearly identify the position of the aluminum box;when the buried depth of aluminum box was more than30 m,the buried depth and position of the aluminum box was not sure due to the unknown level of secondary eddy current field generated by aluminum box.
