This paper analyzes the unified performance of energy detection(ED) of spectrum sensing(SS) over generalized fading channels in cognitive radios(CRs). The detective performance of SS will be obviously affected by fadi...This paper analyzes the unified performance of energy detection(ED) of spectrum sensing(SS) over generalized fading channels in cognitive radios(CRs). The detective performance of SS will be obviously affected by fading channels among communication nodes, and ED has the advantages of fast implementation, no requirement of priori received information and low complexity, so it is meaningful to investigate ED over various fading channels. The probability density function(p.d.f.) of α-κ-μ distribution is derived to evaluate energy efficiency for sensing systems.The detection probability with Marcum-Q function has been derived and the close-form expressions with moment generating function(MGF) method are deduced to achieve SS.Furthermore, exact closed-form analytic expressions for average area under the receiver operating characteristics curve( AUC) also have been deduced to analyze the performance characteristics of ED over α-κ-μ fading channels.Besides, cooperative spectrum sensing(CSS) with diversity reception has been applied to improve the detection accuracy and mitigate the shadowed fading features with OR-rule. At last, the results show that the detection capacity of ED will be evidently affected by α-κ-μ fading channels, but appropriate channel parameters can improve sensing performance. In addition, the establishedED-fading pattern is approved by simulations,and it can significantly enhance the detection performance of proposed algorithms.展开更多
An Olethreutine speciesCymolomia hartigiana (Saxesen, 1840), attacking toAbies nephrolepis Max., is reported for the first time from Daxing'anling, Heilongjiang, China. The morphological characteristics are briefl...An Olethreutine speciesCymolomia hartigiana (Saxesen, 1840), attacking toAbies nephrolepis Max., is reported for the first time from Daxing'anling, Heilongjiang, China. The morphological characteristics are briefly re-described with illustrations. Also its damage and biology are noted. Key words Systematics - Lepidoptera - Tortricidae - Cymolomia - Daxing'anling - China CLC number Q969.429.2 - S763.3 Document code A Foundation item: This study was carried out under the financial support by KOSEF (Korea Science & Engineering Foundation) with the program of “Korea and China Young Scientist Exchange Program” (2002–2003).Biography: *BYUN Bong-Kya (1963-), male, Ph.D., Researcher in Korea National Arboretum, Korea.Responsible editor: Chai Ruihai展开更多
Takayasu＇s arteritis （TA） is a chronic and nonspecific in- flammatory vessel disease that involves the aorta and its major branches. TA results in stenosis, occlusion or aneu- rysmal degeneration of large arteries ...Takayasu＇s arteritis （TA） is a chronic and nonspecific in- flammatory vessel disease that involves the aorta and its major branches. TA results in stenosis, occlusion or aneu- rysmal degeneration of large arteries pathologically. Al- though TA is an unusual disease, it is more commonly ob- served to occur in Asian females compared to the general population worldwide. Aortic dissection is a very rare com- plication of TA, and only a limited number of TA cases presenting with aortic dissection have been published so far.展开更多
Objective To investigate the incidence, imaging and clinical characteristics in elderly patients with coronary artery ectasia （CAE）. Methods A retrospective analysis was conducted on patients with CAE who underwent ...Objective To investigate the incidence, imaging and clinical characteristics in elderly patients with coronary artery ectasia （CAE）. Methods A retrospective analysis was conducted on patients with CAE who underwent coronary angiography between January 2006 and December 2012. According to age, the enrolled patients were divided into two groups （elderly group, age≥ 65 years; non-elderly group, age 〈 65 years）. The clinical feature, imaging characteristics and the 5-year survival rate of the two groups were compared.Results The preva-lence of CAE in elderly patients was 0.33%. Patients in elderly group were found to have significantly higher proportion of female （30.1%vs. 10.1%,P〈 0.001）, three-vessel disease （60.5%vs. 45.2%,P = 0.003） and localized ectasia （55.0%vs. 40.2%,P = 0.003）. In addition, body mass index （20.90 ± 2.71 kg/m2vs. 22.31 ± 2.98 kg/m2,P 〈 0.001） and percentage of current smokers （45.0%vs. 64.6%,P 〈 0.001） were significantly lower in elderly group. Cumulative survival curves demonstrated reduced 5-year cumulative survival at the follow-up in the elderly group compared with the non-elderly group （88.0%vs. 96.0%,P = 0.002）. But the 5-year event free survival rate failed to show a significant difference between the two groups （31.0%vs. 35.0%,P= 0.311）.ConclusionThe prevalence of CAE in elderly patients was 0.33%, which was about 1/3 of the entire numbers of CAE patients. There were significant differences between the elderly and the non-elderly patients with CAE in terms of coronary artery disease risk factors and coronary artery ectatic characteristics. CAE might be asso-ciated with increased mortality risk in the elderly.展开更多
Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and location ＆ frequen...Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and location ＆ frequency of joints or voids. This paper focuses on improving rock characterization algorithms for instrumented roof-boRer systems. For this purpose, an improved void detection algorithm is proposed, where the underlying theory is built upon the concept of mean change detection based on the feed pressure signals. In addition, the application of acoustic sensing for void detection is examined and it is shown that the variance of the filtered acoustic signal is correlated to the strength of the material being drilled. The proposed algorithm has been validated on the data collected from full-scale drilling tests in various concrete and rock samples at the J. H. Fletcher facility.展开更多
The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results sh...The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results show that the antiferromagnetic intralayer coupling J2 has an important influence on internal energy and specific heat for a four-sublattice system with antiferromagnetic （or ferrimagnetic） interlayer couplings.展开更多
Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containi...Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the perrneation of underground water to prevent the surrounding environment from po1lution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material’s dilatancy character,the authors carry out the stress-strain analysis of a thick-wa1l cylinder in a plane strain state subJected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials’ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretlcal analysls methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.展开更多
Adopting an elastic-viscoplastic, the asymptotic problem of mode I propagat ing crack-tip field is investigated. Various asymptotic solutions resulting from the analysis of crack growing programs are presented. The an...Adopting an elastic-viscoplastic, the asymptotic problem of mode I propagat ing crack-tip field is investigated. Various asymptotic solutions resulting from the analysis of crack growing programs are presented. The analysis results show that the quasi-statically growing crack solutions are the special case of the dynamic propagating solutions. Therefore these two asymptotic solutions can be unified.展开更多
基金supported by the science and technology project of state grid headquarters of China (SGLNDK00KJJS1700200)
文摘This paper analyzes the unified performance of energy detection(ED) of spectrum sensing(SS) over generalized fading channels in cognitive radios(CRs). The detective performance of SS will be obviously affected by fading channels among communication nodes, and ED has the advantages of fast implementation, no requirement of priori received information and low complexity, so it is meaningful to investigate ED over various fading channels. The probability density function(p.d.f.) of α-κ-μ distribution is derived to evaluate energy efficiency for sensing systems.The detection probability with Marcum-Q function has been derived and the close-form expressions with moment generating function(MGF) method are deduced to achieve SS.Furthermore, exact closed-form analytic expressions for average area under the receiver operating characteristics curve( AUC) also have been deduced to analyze the performance characteristics of ED over α-κ-μ fading channels.Besides, cooperative spectrum sensing(CSS) with diversity reception has been applied to improve the detection accuracy and mitigate the shadowed fading features with OR-rule. At last, the results show that the detection capacity of ED will be evidently affected by α-κ-μ fading channels, but appropriate channel parameters can improve sensing performance. In addition, the establishedED-fading pattern is approved by simulations,and it can significantly enhance the detection performance of proposed algorithms.
基金Carried out under the financial support by KOSEF (Korea Science & Engineering Foundation) with the program of "Korea and China Young Scientist Exchange Program' (2002 2003).
文摘An Olethreutine speciesCymolomia hartigiana (Saxesen, 1840), attacking toAbies nephrolepis Max., is reported for the first time from Daxing'anling, Heilongjiang, China. The morphological characteristics are briefly re-described with illustrations. Also its damage and biology are noted. Key words Systematics - Lepidoptera - Tortricidae - Cymolomia - Daxing'anling - China CLC number Q969.429.2 - S763.3 Document code A Foundation item: This study was carried out under the financial support by KOSEF (Korea Science & Engineering Foundation) with the program of “Korea and China Young Scientist Exchange Program” (2002–2003).Biography: *BYUN Bong-Kya (1963-), male, Ph.D., Researcher in Korea National Arboretum, Korea.Responsible editor: Chai Ruihai
文摘Takayasu＇s arteritis （TA） is a chronic and nonspecific in- flammatory vessel disease that involves the aorta and its major branches. TA results in stenosis, occlusion or aneu- rysmal degeneration of large arteries pathologically. Al- though TA is an unusual disease, it is more commonly ob- served to occur in Asian females compared to the general population worldwide. Aortic dissection is a very rare com- plication of TA, and only a limited number of TA cases presenting with aortic dissection have been published so far.
基金This article is partly supported by National Natural Sci-entific Foundation，Specialized Re-search Fund for the Doctoral Program of Higher Education of China，Fund of Capital Special Founda-tion of Clinical Application Research，Capital Health Development Fund，Bei-jing Natural Science Foundation （7131014） awarded to Dr. Jian-Jun Li
文摘Objective To investigate the incidence, imaging and clinical characteristics in elderly patients with coronary artery ectasia （CAE）. Methods A retrospective analysis was conducted on patients with CAE who underwent coronary angiography between January 2006 and December 2012. According to age, the enrolled patients were divided into two groups （elderly group, age≥ 65 years; non-elderly group, age 〈 65 years）. The clinical feature, imaging characteristics and the 5-year survival rate of the two groups were compared.Results The preva-lence of CAE in elderly patients was 0.33%. Patients in elderly group were found to have significantly higher proportion of female （30.1%vs. 10.1%,P〈 0.001）, three-vessel disease （60.5%vs. 45.2%,P = 0.003） and localized ectasia （55.0%vs. 40.2%,P = 0.003）. In addition, body mass index （20.90 ± 2.71 kg/m2vs. 22.31 ± 2.98 kg/m2,P 〈 0.001） and percentage of current smokers （45.0%vs. 64.6%,P 〈 0.001） were significantly lower in elderly group. Cumulative survival curves demonstrated reduced 5-year cumulative survival at the follow-up in the elderly group compared with the non-elderly group （88.0%vs. 96.0%,P = 0.002）. But the 5-year event free survival rate failed to show a significant difference between the two groups （31.0%vs. 35.0%,P= 0.311）.ConclusionThe prevalence of CAE in elderly patients was 0.33%, which was about 1/3 of the entire numbers of CAE patients. There were significant differences between the elderly and the non-elderly patients with CAE in terms of coronary artery disease risk factors and coronary artery ectatic characteristics. CAE might be asso-ciated with increased mortality risk in the elderly.
基金funded by National Institute of Occupational Safety and Health (NIOSH) ground control group under the contract No. 211-2011-41138
文摘Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and location ＆ frequency of joints or voids. This paper focuses on improving rock characterization algorithms for instrumented roof-boRer systems. For this purpose, an improved void detection algorithm is proposed, where the underlying theory is built upon the concept of mean change detection based on the feed pressure signals. In addition, the application of acoustic sensing for void detection is examined and it is shown that the variance of the filtered acoustic signal is correlated to the strength of the material being drilled. The proposed algorithm has been validated on the data collected from full-scale drilling tests in various concrete and rock samples at the J. H. Fletcher facility.
基金Project supported by the Natural Science Foundation of Liaoning Province （Grant No 20041021）, the Scientific Foundation of the Educational Department of Liaoning Province （Grant No 2004C006） and the Postdoctoral Foundation of Shenyang University of Technology.
文摘The internal energy and specific heat of a Heisenberg ferro- antiferromagnetic double-layer system are studied by using spin-wave theory and the retarded Green function method at low temperatures. Numerical results show that the antiferromagnetic intralayer coupling J2 has an important influence on internal energy and specific heat for a four-sublattice system with antiferromagnetic （or ferrimagnetic） interlayer couplings.
文摘Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the perrneation of underground water to prevent the surrounding environment from po1lution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material’s dilatancy character,the authors carry out the stress-strain analysis of a thick-wa1l cylinder in a plane strain state subJected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials’ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretlcal analysls methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.
文摘Adopting an elastic-viscoplastic, the asymptotic problem of mode I propagat ing crack-tip field is investigated. Various asymptotic solutions resulting from the analysis of crack growing programs are presented. The analysis results show that the quasi-statically growing crack solutions are the special case of the dynamic propagating solutions. Therefore these two asymptotic solutions can be unified.
