The aim of this paper is to investigate the area spectrum of the three-dimensional Godel black hole by using two different methods. The result shows that the area spectrum of the black hole is △A = 8πl2p, which conf...The aim of this paper is to investigate the area spectrum of the three-dimensional Godel black hole by using two different methods. The result shows that the area spectrum of the black hole is △A = 8πl2p, which confirms the initial proposal of Bekenstein that the area spectrum is independent of black hole parameters and the spacing is 8πl2p.展开更多
Nowadays, tourism has become an increasingly significant driving force of modern urbanization in China. However, it has caused varieties of problems, such as resource unreasonable utilization, society unfair play, and...Nowadays, tourism has become an increasingly significant driving force of modern urbanization in China. However, it has caused varieties of problems, such as resource unreasonable utilization, society unfair play, and environment pollution, etc. Thus, the establishment of an efficient and sustainable space partition model for tourism urbanization, from the geographical perspective, is highly necessary and urgent. Herein, a new evaluation model of tourist town space, referred to as Tourism Sectorization Opportunity Spectrum(TSOS), is established on the relationships between productionliving-ecology spaces. TSOS is a kind of quantitative evaluation model involving such factors as urban living area, ecological conservation area and the tourism industry. Furthermore, the analysis of quantitative production-living-ecology spatial overlap has been utilized for space division in a tourism urbanization area. This paper, using both the TSOS model and GIS technology, analyzes the spatial restructure of the Mayangxi ecotourism area. Theresult demonstrates that tourism industrial space takes the Shanchong Village as a core which shows a pattern of local regional agglomeration and a fuzzy edge extending along the entire Mayangxi River. The urban living area should be consolidated in the Shili village with the supporting facilities and living space for tourism. In addition, Tianzhu Mountain forest park should be the key environmental protection area. The case study on the Mayangxi ecotourism area verifies that the TSOS model has strong operability. Therefore, TSOS model provides a scientific foundation for the space reconstruction of new urbanization area, and an effective tool for optimizing the space partition of a tourism urbanization area.展开更多
Mutations in GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the spectrum and prevalence of mutations in this gene vary among different ethnic groups. In Ch...Mutations in GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the spectrum and prevalence of mutations in this gene vary among different ethnic groups. In China, 30,000 infants are born with congenital hearing impairment annually. In order to provide appropriate genetic testing and counseling to the families, we investigated the molecular etiology of nonsyndromic deafness in 103 unrelated school children attending Nantong School for the Deaf and Mute in Jiangsu Province, China. The coding exon of the GJB2 gene was PCR amplified and sequenced. Sixty two GJB2 mutant alleles were identified in 35.9% (37/103) of the patients. Twenty five patients carried two pathogenic mutations and 12 patients carried one mutant allele. The 235delC was the most common mutation accounting for 69.4% (43/62) of GJB2 mutant alleles. The GJB2 mutant alleles accounted for 30.1% (62/206) of all chromosomes responsible for nonsyndromic hearing impairment. Testing of the 3 most prevalent deleterious frame shift mutations in this cohort detected 100% of all GJB2 mutant alleles. These results demonstrate that an effective genetic testing of GJB2 gene for patients and families with nonsyndromic hearing impairment is possible.展开更多
Stochastic geometry is widely employed to model cellular network. But in most existing works, base stations(BSs) are modelled following a homogeneous Poisson point process(PPP) for one-tier network, or several indepen...Stochastic geometry is widely employed to model cellular network. But in most existing works, base stations(BSs) are modelled following a homogeneous Poisson point process(PPP) for one-tier network, or several independent homogeneous PPP for multi-tier network, which ignore the dependence among BSs. In this paper, a three-tier UDN(Ultra dense network) with Macrocell BSs(MBS) for basic coverage, Picocell BSs(PBSs) deployed outside the coverage area of MBSs for compensating coverage holes, and Femtocell BSs(FBSs) surrounding MBSs for capacity improvement modelled by point process with inter-tier dependence is proposed. The tier association probability, the coverage probability and area spectrum efficiency(ASE) are derived. Simulation results validate our derivation, and results show that the proposed network model has 25%-45% performance gain in ASE.展开更多
Based on the electrical model of body area communication, the change tendency of chan nel gain in 100 kHz 10 MHz band was experimentally analyzed and verified. Results show that chan nel gain was flat and signal a...Based on the electrical model of body area communication, the change tendency of chan nel gain in 100 kHz 10 MHz band was experimentally analyzed and verified. Results show that chan nel gain was flat and signal attenuation was approximately 43 dB in 1 MHz 10 MHz band. The char acteristics of the channel were taken into account in the design of body area spread spectrum com munication and its multiuser receiver issue. BER Eb/No curves of single user and multiuser were de rived by simulation. The characteristics of body area commutation channel were studied and the fea sibility of introducing spread spectrum theory to body area communication was verified.展开更多
Leaf area index （LAI） is an important characteristic of land surface vegetation system, and is also a key parameter for the models of global water balancing and carbon circulation. By using the reflectance values of...Leaf area index （LAI） is an important characteristic of land surface vegetation system, and is also a key parameter for the models of global water balancing and carbon circulation. By using the reflectance values of Landsat-5 blue, green and red channels simulated from rice reflectance spectrum, the sensitivities of the bands to LAI were analyzed, and the response and capability to estimate LAI of various NDVIs （normalized difference vegetation indices）, which were established by substituting the red band of general NDVI with all possible combinations of red, green and blue bands, were assessed. Finally, the conclusion was tested by rice data at different conditions. The sensitivities of red, green and blue bands to LAI were different under various conditions. When LAI was less than 3, red and blue bands were more sensitive to LAI. Though green band in the circumstances was less sensitive to LAI than red and blue bands, it was sensitive to LAI in a wider range. When the vegetation indices were constituted by all kinds of combinations of red, green and blue bands, the premise for making the sensitivity of these vegetation indices to LAI be meaningful was that the value of one of the combinations was greater than 0.024, i.e. visible reflectance （VIS）〉0.024. Otherwise, the vegetation indices would be saturated, resulting in lower estimation accuracy of LAI. Comparison on the capabilities of the vegetation indices derived from all kinds of combinations of red, green and blue bands to LAI estimation showed that GNDVI （Green NDVI） and GBNDVI （Green-Blue NDVI） had the best relations with LAI. The capabilities of GNDVI and GBNDVI to LAI estimation were tested under different circumstances, and the same result was acquired. It suggested that GNDVI and GBNDVI performed better to predict LAI than the conventional NDVI.展开更多
By considering and using an adiabatic invariant for black holes, the area and entropy spectra of static spherically- symmetric black holes are investigated. Without using quasi-normal modes of black holes, equally-spa...By considering and using an adiabatic invariant for black holes, the area and entropy spectra of static spherically- symmetric black holes are investigated. Without using quasi-normal modes of black holes, equally-spaced area and entropy spectra are derived by only utilizing the adiabatic invariant. The spectra for non-charged and charged black holes are calculated, respectively. All these results are consistent with the original Bekenstein spectra.展开更多
The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networ...The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networks and propose a new graph-theory algorithm. The algorithm aims at two objectives: one is the sum of the allocated channel bandwidth is maximum, and the other is the number of users can be active simultaneity is maximum. In this proposed algorithm, the topology of network was modeled as a general graph and could be transformed into a weighted complete bipartite-graph by three processes. The simulations show that the presented algorithm can improve the performance of spectrum allocation.展开更多
为探讨基于无人机RGB影像实现对小麦叶面积指数(leaf area index,LAI)和产量估算的可行性,设置不同生态点、品种和氮素处理的小麦田间试验,应用大疆精灵4 Pro无人机获取小麦拔节期、抽穗期、扬花期和灌浆期4个主要生育时期的RGB高时空...为探讨基于无人机RGB影像实现对小麦叶面积指数(leaf area index,LAI)和产量估算的可行性,设置不同生态点、品种和氮素处理的小麦田间试验,应用大疆精灵4 Pro无人机获取小麦拔节期、抽穗期、扬花期和灌浆期4个主要生育时期的RGB高时空分辨率影像,并同测定小麦LAI。采用相关性分析筛选出不同生育时期对LAI敏感的光谱与纹理特征集,并借助随机森林(random forest,RF)、偏最小二乘回归法(partial least squares regression,PLSR)、BP神经网络(back propagation neural network,BPNN)和支持向量机(support vector machine,SVM)分析方法,筛选出小麦不同生育时期最优的LAI估测模型。基于不同生育时期的光谱与纹理特征以及时期特征集,进一步建立产量预测模型,并在不同生态点验证叶面积估算模型与产量预测模型的普适性。结果表明,基于RF的LAI估测模型的验证精度最高,4个生育时期的均方根误差(root mean square error,RMSE)分别为2.26、1.44、1.73和1.02。基于RF的产量预测模型验证效果也最优,RMSE为1.17 t·hm^(-2)。由此说明基于无人机RGB影像和RF算法,建立LAI和产量估测模型,可实现小麦长势实时监测和产量预测。展开更多
公路立交合流区交通环境复杂,交织比例和换道频次高,危险系数大。为描述合流场景下危险驾驶行为的主要表现形式,同时,量化其危险程度,提出操纵量指标表征立交合流区危险驾驶行为,构建基于车辆轨迹数据特征参数的驾驶行为谱;运用风险度...公路立交合流区交通环境复杂,交织比例和换道频次高,危险系数大。为描述合流场景下危险驾驶行为的主要表现形式,同时,量化其危险程度,提出操纵量指标表征立交合流区危险驾驶行为,构建基于车辆轨迹数据特征参数的驾驶行为谱;运用风险度量法量化4种危险驾驶行为,即急打方向、猛踩踏板、危险跟驰和危险换道。结合四分位差法和CRITIC(Criteria Importance Though Intercrieria Correlation)法确定危险驾驶行为特征参数阈值和权重,并综合计算危险驾驶行为谱特征值;结合危险点空间分布及相关研究验证操纵量指标的有效性。研究结果表明:4种危险驾驶行为相关系数均小于0.2,不存在共线性;4种危险驾驶行为中,急打方向权重占比最高,为0.405,对合流区行车安全影响最大;操纵量指标危险点空间分布与现有研究合流区交通冲突点吻合。上述结果证明:采用操纵量指标建立的危险驾驶行为谱可以客观实时的结合车辆轨迹数据辨识合流区危险驾驶人,为公路立交合流区主动安全防控提供依据。展开更多
基金Project supported by the Scientific Research Foundation of the Education Department of Liaoning Province, China （Grant No. L2011195）.
文摘The aim of this paper is to investigate the area spectrum of the three-dimensional Godel black hole by using two different methods. The result shows that the area spectrum of the black hole is △A = 8πl2p, which confirms the initial proposal of Bekenstein that the area spectrum is independent of black hole parameters and the spacing is 8πl2p.
基金supported and funded by the National Natural Science Foundation of China(Grant No.41071110)the State Ethnic Affairs Youth Foundation of China(Grant No.2015-GM073)
文摘Nowadays, tourism has become an increasingly significant driving force of modern urbanization in China. However, it has caused varieties of problems, such as resource unreasonable utilization, society unfair play, and environment pollution, etc. Thus, the establishment of an efficient and sustainable space partition model for tourism urbanization, from the geographical perspective, is highly necessary and urgent. Herein, a new evaluation model of tourist town space, referred to as Tourism Sectorization Opportunity Spectrum(TSOS), is established on the relationships between productionliving-ecology spaces. TSOS is a kind of quantitative evaluation model involving such factors as urban living area, ecological conservation area and the tourism industry. Furthermore, the analysis of quantitative production-living-ecology spatial overlap has been utilized for space division in a tourism urbanization area. This paper, using both the TSOS model and GIS technology, analyzes the spatial restructure of the Mayangxi ecotourism area. Theresult demonstrates that tourism industrial space takes the Shanchong Village as a core which shows a pattern of local regional agglomeration and a fuzzy edge extending along the entire Mayangxi River. The urban living area should be consolidated in the Shili village with the supporting facilities and living space for tourism. In addition, Tianzhu Mountain forest park should be the key environmental protection area. The case study on the Mayangxi ecotourism area verifies that the TSOS model has strong operability. Therefore, TSOS model provides a scientific foundation for the space reconstruction of new urbanization area, and an effective tool for optimizing the space partition of a tourism urbanization area.
基金This work was supported by the Chinese National Nature Science Foundation research Grant 30572015Beijing Nature Science Foundation research Grant 7062062.
文摘Mutations in GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the spectrum and prevalence of mutations in this gene vary among different ethnic groups. In China, 30,000 infants are born with congenital hearing impairment annually. In order to provide appropriate genetic testing and counseling to the families, we investigated the molecular etiology of nonsyndromic deafness in 103 unrelated school children attending Nantong School for the Deaf and Mute in Jiangsu Province, China. The coding exon of the GJB2 gene was PCR amplified and sequenced. Sixty two GJB2 mutant alleles were identified in 35.9% (37/103) of the patients. Twenty five patients carried two pathogenic mutations and 12 patients carried one mutant allele. The 235delC was the most common mutation accounting for 69.4% (43/62) of GJB2 mutant alleles. The GJB2 mutant alleles accounted for 30.1% (62/206) of all chromosomes responsible for nonsyndromic hearing impairment. Testing of the 3 most prevalent deleterious frame shift mutations in this cohort detected 100% of all GJB2 mutant alleles. These results demonstrate that an effective genetic testing of GJB2 gene for patients and families with nonsyndromic hearing impairment is possible.
基金partially supported by National 863 Program (2014AA01A702)national major project (2016ZX03001011-005)national natural science foundation project (61521061)
文摘Stochastic geometry is widely employed to model cellular network. But in most existing works, base stations(BSs) are modelled following a homogeneous Poisson point process(PPP) for one-tier network, or several independent homogeneous PPP for multi-tier network, which ignore the dependence among BSs. In this paper, a three-tier UDN(Ultra dense network) with Macrocell BSs(MBS) for basic coverage, Picocell BSs(PBSs) deployed outside the coverage area of MBSs for compensating coverage holes, and Femtocell BSs(FBSs) surrounding MBSs for capacity improvement modelled by point process with inter-tier dependence is proposed. The tier association probability, the coverage probability and area spectrum efficiency(ASE) are derived. Simulation results validate our derivation, and results show that the proposed network model has 25%-45% performance gain in ASE.
基金Supported by the National Natural Science Foundation of China under Grant No.10275030Cuiying Project of Lanzhou University under Grant No.225000-582404
基金Supported by the Ministerial Level Advanced Research Foundation(7130819)
文摘Based on the electrical model of body area communication, the change tendency of chan nel gain in 100 kHz 10 MHz band was experimentally analyzed and verified. Results show that chan nel gain was flat and signal attenuation was approximately 43 dB in 1 MHz 10 MHz band. The char acteristics of the channel were taken into account in the design of body area spread spectrum com munication and its multiuser receiver issue. BER Eb/No curves of single user and multiuser were de rived by simulation. The characteristics of body area commutation channel were studied and the fea sibility of introducing spread spectrum theory to body area communication was verified.
文摘Leaf area index （LAI） is an important characteristic of land surface vegetation system, and is also a key parameter for the models of global water balancing and carbon circulation. By using the reflectance values of Landsat-5 blue, green and red channels simulated from rice reflectance spectrum, the sensitivities of the bands to LAI were analyzed, and the response and capability to estimate LAI of various NDVIs （normalized difference vegetation indices）, which were established by substituting the red band of general NDVI with all possible combinations of red, green and blue bands, were assessed. Finally, the conclusion was tested by rice data at different conditions. The sensitivities of red, green and blue bands to LAI were different under various conditions. When LAI was less than 3, red and blue bands were more sensitive to LAI. Though green band in the circumstances was less sensitive to LAI than red and blue bands, it was sensitive to LAI in a wider range. When the vegetation indices were constituted by all kinds of combinations of red, green and blue bands, the premise for making the sensitivity of these vegetation indices to LAI be meaningful was that the value of one of the combinations was greater than 0.024, i.e. visible reflectance （VIS）〉0.024. Otherwise, the vegetation indices would be saturated, resulting in lower estimation accuracy of LAI. Comparison on the capabilities of the vegetation indices derived from all kinds of combinations of red, green and blue bands to LAI estimation showed that GNDVI （Green NDVI） and GBNDVI （Green-Blue NDVI） had the best relations with LAI. The capabilities of GNDVI and GBNDVI to LAI estimation were tested under different circumstances, and the same result was acquired. It suggested that GNDVI and GBNDVI performed better to predict LAI than the conventional NDVI.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11045005)the Natural Science Foundation of Zhejiang Province of China (Grant No. Y6090739)
文摘By considering and using an adiabatic invariant for black holes, the area and entropy spectra of static spherically- symmetric black holes are investigated. Without using quasi-normal modes of black holes, equally-spaced area and entropy spectra are derived by only utilizing the adiabatic invariant. The spectra for non-charged and charged black holes are calculated, respectively. All these results are consistent with the original Bekenstein spectra.
文摘The IEEE 802.22 standard based on wireless Cognitive Radio (CR) is an optimal solution to resolve the inefficient spectrum utility problem. In this paper, we focus on the spectrum allocation in IEEE 802.22 mesh networks and propose a new graph-theory algorithm. The algorithm aims at two objectives: one is the sum of the allocated channel bandwidth is maximum, and the other is the number of users can be active simultaneity is maximum. In this proposed algorithm, the topology of network was modeled as a general graph and could be transformed into a weighted complete bipartite-graph by three processes. The simulations show that the presented algorithm can improve the performance of spectrum allocation.
文摘公路立交合流区交通环境复杂,交织比例和换道频次高,危险系数大。为描述合流场景下危险驾驶行为的主要表现形式,同时,量化其危险程度,提出操纵量指标表征立交合流区危险驾驶行为,构建基于车辆轨迹数据特征参数的驾驶行为谱;运用风险度量法量化4种危险驾驶行为,即急打方向、猛踩踏板、危险跟驰和危险换道。结合四分位差法和CRITIC(Criteria Importance Though Intercrieria Correlation)法确定危险驾驶行为特征参数阈值和权重,并综合计算危险驾驶行为谱特征值;结合危险点空间分布及相关研究验证操纵量指标的有效性。研究结果表明:4种危险驾驶行为相关系数均小于0.2,不存在共线性;4种危险驾驶行为中,急打方向权重占比最高,为0.405,对合流区行车安全影响最大;操纵量指标危险点空间分布与现有研究合流区交通冲突点吻合。上述结果证明:采用操纵量指标建立的危险驾驶行为谱可以客观实时的结合车辆轨迹数据辨识合流区危险驾驶人,为公路立交合流区主动安全防控提供依据。
