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Random testing for system-level functional verification of system-on-chip 被引量:4
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作者 Ma Qinsheng Cao Yang +1 位作者 Yang Jun Wang Min 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1378-1383,共6页
In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity o... In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity of this method is proven theoretically.Specifically, testcases are generated according to many approaches of randomization.Moreover, the testbench for the system-level verification according to the proposed method is designed by using advanced modeling language.Therefore, under the circumstances that the testbench generates testcases quickly, the hardware/software co-simulation and co-verification can be implemented and the hardware/software partitioning planning can be evaluated easily.The comparison method is put to use in the evaluation approach of the testing validity.The evaluation result indicates that the efficiency of the partition testing is better than that of the random testing only when one or more subdomains are covered over with the area of errors, although the efficiency of the random testing is generally better than that of the partition testing.The experimental result indicates that this method has a good performance in the functional coverage and the cost of testing and can discover the functional errors as soon as possible. 展开更多
关键词 VLSI circuit VERIFICATION random process function TESTING SYSTEM-ON-CHIP system-level.
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Emotion processing in Parkinson's disease: a blood oxygenation level-dependent functional magnetic resonance imaging study 被引量:6
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作者 Mohammed Benzagmout Sa?d Boujraf +8 位作者 Badreeddine Alami Hassane Ali Amadou Halima El Hamdaoui Amine Bennani Mounir Jaafari Ismail Rammouz Mustapha Maaroufi Rabia Magoul Driss Boussaoud 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第4期666-672,共7页
Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor i... Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade. The aim of this study was to investigate emotional processing organization in the brain of patients with Parkinson's disease and to explore whether there are differences between recognition of different types of emotions in Parkinson's disease. We examined 18 patients with Parkinson's disease(8 men, 10 women) with no history of neurological or psychiatric comorbidities. All these patients underwent identical brain blood oxygenation level-dependent functional magnetic resonance imaging for emotion evaluation. Blood oxygenation level-dependent functional magnetic resonance imaging results revealed that the occipito-temporal cortices, insula, orbitofrontal cortex, basal ganglia, and parietal cortex which are involved in emotion processing, were activated during the functional control. Additionally, positive emotions activate larger volumes of the same anatomical entities than neutral and negative emotions. Results also revealed that Parkinson's disease associated with emotional disorders are increasingly recognized as disabling as classic motor symptoms. These findings help clinical physicians to recognize the emotional dysfunction of patients with Parkinson's disease. 展开更多
关键词 Parkinson’s disease EMOTION processing BLOOD OXYGENATION level-dependent functional magnetic resonance imaging brain activation DOPAMINE neural REGENERATION
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Weighted Multi-sensor Data Level Fusion Method of Vibration Signal Based on Correlation Function 被引量:7
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作者 BIN Guangfu JIANG Zhinong +1 位作者 LI Xuejun DHILLON B S 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期899-904,共6页
As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery... As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery fault diagnosis.The traditional signal processing methods,such as classical inference and weighted averaging algorithm usually lack dynamic adaptability that is easy for trends to cause the faults to be misjudged or left out.To enhance the measuring veracity and precision of vibration signal in rotary machine multi-sensor vibration signal fault diagnosis,a novel data level fusion approach is presented on the basis of correlation function analysis to fast determine the weighted value of multi-sensor vibration signals.The approach doesn't require knowing the prior information about sensors,and the weighted value of sensors can be confirmed depending on the correlation measure of real-time data tested in the data level fusion process.It gives greater weighted value to the greater correlation measure of sensor signals,and vice versa.The approach can effectively suppress large errors and even can still fuse data in the case of sensor failures because it takes full advantage of sensor's own-information to determine the weighted value.Moreover,it has good performance of anti-jamming due to the correlation measures between noise and effective signals are usually small.Through the simulation of typical signal collected from multi-sensors,the comparative analysis of dynamic adaptability and fault tolerance between the proposed approach and traditional weighted averaging approach is taken.Finally,the rotor dynamics and integrated fault simulator is taken as an example to verify the feasibility and advantages of the proposed approach,it is shown that the multi-sensor data level fusion based on correlation function weighted approach is better than the traditional weighted average approach with respect to fusion precision and dynamic adaptability.Meantime,the approach is adaptable and easy to use,can be applied to other areas of vibration measurement. 展开更多
关键词 vibration signal MULTI-SENSOR data level fusion correlation function weighted value
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The Single Valley Character of Level Degree Function
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作者 傅增明 佟晓石 《Journal of Donghua University(English Edition)》 EI CAS 2004年第4期153-155,共3页
Strict proof has been given to single valley character of level degree function by use of convex analysis theory, which provides reliable theoretical basis for the optimization of the data processing with respect to l... Strict proof has been given to single valley character of level degree function by use of convex analysis theory, which provides reliable theoretical basis for the optimization of the data processing with respect to level degree. As circle degree and cylindrical degree have the same mathematical structures, their single valley character can be proved by the same method. 展开更多
关键词 Convex Analysis Theory level Degree function Single Valley Character.
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Effect of Intermittent Pneumatic Compression on Functional Level and Quality of Life in Community-Dwelling Older Adults with Limited Ambulation Due to Leg Pain: A Randomized Controlled Trial
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作者 Weerasinghe Mudiyanselage Sujeewa Weerasinghe Thunpaththu Mudiyanselage Upul Sanjeewa Thunpaththu +4 位作者 Weerasinghe Mudiyanselage Sandali Anjana Weerasinghe Weerasinghe Mudiyanselage Shalindu Thushen Weerasinghe Pahala Walpola Gamarallage Shirani Walpola Dissanayaka Mudiyanselage Tharanga Padmini Dissanayaka Angelo Karunaratne 《Health》 2021年第10期1145-1169,共25页
<strong>Background and Purpose:</strong> Walking difficulties are defined as any reduction in speed, balance, or change of gait, causing limited ambulation. These difficulties are a common problem in older... <strong>Background and Purpose:</strong> Walking difficulties are defined as any reduction in speed, balance, or change of gait, causing limited ambulation. These difficulties are a common problem in older adults and may greatly affect their quality of life (QOL) and restrict their personal independence and participation. This study aimed to determine the effect of intermittent pneumatic compression (IPC) on lower leg pain, walking capacity, functional mobility, ankle range of motion (AROM), and QOL of community-dwelling older people with walking difficulties. <strong>Methods:</strong> In this randomized controlled trial, 34 eligible participants with self-reported lower limb pain and limited ambulation were randomized either to the intermittent pneumatic compression intervention group (IPCIG) or static compression control group (SCCG). The IPCIG and SCCG were trained to receive IPC and SC respectively for both lower legs and instructed to continue the application independently at home for 15 minutes per session, 2 sessions a day, 7 days per week for 4 weeks independently at the home. Outcome measures of lower leg pain, AROM, walking capacity, and functional mobility were assessed at baseline and at the first, second, third, and fourth weeks after randomization. Quality of life was assessed at baseline and immediately after the intervention. <strong>Results and Discussion:</strong> IPCIG showed a more significant improvement compared to the SCCG at the post-interventional stage for QOL and all the subscales. The findings show that “80% improved QOL” is 53% higher with the application of IPC than with SC for 4 weeks. The IPCIG showed a more significant improvement in the 6-minute walk test (6 MWT) at the third and fourth weeks compared to the SCCG. A pairwise comparison of mean values of 6 MWT over 4 weeks within the IPCIG showed a significant difference between all the weeks. Pairwise comparisons between groups at each time point showed that the IPCIG showed a more significant improvement in the timed up and go (TUG) test at the third and fourth weeks compared to the SCCG. Pairwise comparison of mean values of TUG test within the IPCIG showed a significant difference over 4 weeks, except between the second and third weeks, fourth week, and third and fourth weeks. The IPCIG showed a more significant improvement in lower leg pain between all weeks except the first week compared to the SCCG. Pairwise comparison of mean values of lower leg pain over 4 weeks within the IPCIG showed a significant difference among all weekly outcomes except between 1 and 2 weeks. The IPCIG showed a more significant improvement in left and right ankle dorsiflexion ROM at the third and fourth weeks compared to the SCCG. <strong>Conclusions:</strong> The IPC was effective in reducing lower leg pain and increasing the AROM and improving the walking capacity, functional mobility level, and QOL of community-dwelling older people with walking disabilities. Walking disability in old age is a common condition requiring physical therapy. Intermittent pneumatic compression can be used as a physical therapy modality for this patient group. 展开更多
关键词 Intermittent Pneumatic Compression functional level Quality of Life Older Adults Limited Ambulation Leg Pain
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Impact of Nonlethal Levels of Metacid-50 and Carbaryl on Thyroid Function and Cholinergic System of Channa punctatus 被引量:1
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作者 PROBODHGHOSH SAMIRBHATTACHARYA SHELLEYBHATTACHARYA 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1989年第2期92-97,共6页
With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine(T_3) and thyroxine(T_4)profiles,a biphasic response pattern was elicited in Channa punctatus chroni- cally exposed to nonlethal do... With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine(T_3) and thyroxine(T_4)profiles,a biphasic response pattern was elicited in Channa punctatus chroni- cally exposed to nonlethal doses of locally used pesticides,namely,Metacid-50 and Carbaryl. Data revealed that these xenobiotics caused significant inhibition of brain acetylcholinesterase activity and a decrease in thyroxine level accompanied by a concurrent increase in acetylcholine accumulation and T_3 level.It is surmised that Metacid-50 and Carbaryl influence both neural and hormonal functions.1989 Academic Press.Inc. 展开更多
关键词 In Impact of Nonlethal levels of Metacid-50 and Carbaryl on Thyroid function and Cholinergic System of Channa punctatus ACHE
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TWO-LEVEL METHOD FOR UNSTEADY NAVIER-STOKES EQUATIONS IN STREAM FUNCTION FORM
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作者 RenChunfeng MaYichen XuHui 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第1期105-120,共16页
Two-level finite element approximation to stream function form of unsteady Navier-Stokes equations is studied.This algorithm involves solving one nonlinear system on a coarse grid and one linear problem on a fine grid... Two-level finite element approximation to stream function form of unsteady Navier-Stokes equations is studied.This algorithm involves solving one nonlinear system on a coarse grid and one linear problem on a fine grid.Moreover,the scaling between these two grid sizes is super-linear.Approximation,stability and convergence aspects of a fully discrete scheme are analyzed.At last a numrical example is given whose results show that the algorithm proposed in this paper is effcient. 展开更多
关键词 Navier-Stokes equations two-level method stream function APPROXIMATION STABILITY convergence.
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Nonconstant Harmonic Functions on the Level 3 Sierpinski Gasket
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作者 Donglei Tang Rui Hu 《Analysis in Theory and Applications》 2014年第4期417-424,共8页
We give a detailed description of nonconstant harmonic functions on the level 3 Sierpinski gasket. Then we extend the method onβ-set with 1/3〈β〈1/2.
关键词 Nonconstant harmonic function level 3 Sierpinski gasket β-set.
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Philosophy of GodForm:Power Authorities, Functional Position Levels, Religion and Science
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作者 Refet Ramiz 《Journal of Philosophy Study》 2021年第3期166-215,共50页
In this work,author expressed new R-Synthesis specifically.Good and/or correct perspective that must be behind the definitions and administration generally expressed.New perspective of the philosophy explained general... In this work,author expressed new R-Synthesis specifically.Good and/or correct perspective that must be behind the definitions and administration generally expressed.New perspective of the philosophy explained generally.Philosophy of GodForm is defined and expressed as connected/related with the following concepts:(a)basic principles,(b)17 upper constructional philosophies,(c)14 lower constructional philosophies,(d)eight basic philosophies.As special cases,Philosophy of Engineering and Technology,Philosophy of Wireless Administration and others defined as hybrid philosophies.17 specific components/units which can be considered to define the basic principles of the related formation,are proposed to be designed by GodForm and defined by the author.Philosophy of GodForm and its relation with Values and Positions specifically defined.New Era Theory and New Era Belief explained generally.Some specific religions/beliefs are defined as variants/forms of the Progressive Religion.Good and/or correct power authorities(R-Power Authority)are defined due to 29 categories.Functional position levels defined for the R-Power Authorities with a unique table.As result of the R-Synthesis,functional position levels of some philosophers,some scientists,and of Prophet Jesus,Prophet Mohamed,Prophets Mouses,Buddha,and of Confucius generally/specifically defined.Integration and past/present effects of some R-Power Authorities in 5 x 5 Ideal Political Construction specifically explained.New Era Belief,Concepts of GodX and Science relation explained with the following concepts:(1)Religion of GodForm,(2)Knowledge of GodX,(3)Nature of GodX.With this respect,some other characteristics of 7 GodX power authorities expressed with details as complementary information.Following concepts/systems defined to arrange and solve some/most/all religious problems,which are determined with R-Synthesis:(a)Religious Responsibilities and Positions,(b)Ideal Religious Administration,(c)Sustainable/Continuable Political Administration System,(d)Community Values Council/Authority for each world country,(e)Progressive Councils.15 general religious position categories defined to express their good and/or correct meanings/values/responsibilities in the religious system.21 general/specific cases/programs defined due to New Era Belief to solve possible past/present/future community values problems,to have continuous,judicious,and progressive administration about the 36 kinds of community values.Progressive Councils,which are related with the CUS-WW-HO,are defined.Progressive Religion Council and some of the related religious responsibilities expressed for the kind progressive religion studies due to the Philosophy of Progressive Religions. 展开更多
关键词 PHILOSOPHY New Era Philosophy Philosophy of GodX philosophy of religion religion and science New Era Theory New Era Belief Progressive Religions power authorities functional position levels
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LEVEL SET METHODS BASED ON DISTANCE FUNCTION
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作者 王德军 唐云 +1 位作者 于洪川 唐泽圣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第8期950-960,共11页
Some basic problems on the level set methods were discussed, such as the method used to preserve the distance junction , the existence and uniqueness of solution for the level set equations. The main contribution is t... Some basic problems on the level set methods were discussed, such as the method used to preserve the distance junction , the existence and uniqueness of solution for the level set equations. The main contribution is to prove that in a neighborhood of the initial zero level set, the level set equations with the restriction of the distance function have a unique solution, which must be the signed distance function with respect to the evolving surface. Some skillful approaches were used: Noticing that any solution for the original equation was a distance function, the original level set equations were transformed into a simpler alternative form. Moreover, since the new system was not a classical one, the system was transformed into an ordinary one, for which the implicit function method was adopted. 展开更多
关键词 level set methods distance function existence and uniqueness of the solution
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Investigation of analytical harmonic frequency and potential energy function, vibrational levels for the X^2∑^+ and A^2Л states of CN radical
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作者 Wang Jian-Kun Wu Zhen-Sen 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期2919-2924,共6页
This paper calculates the equilibrium structure and the potential energy functions of the ground state (X^2∑^+) and the low lying excited electronic state (A^2Л) of CN radical are calculated by using CASSCF met... This paper calculates the equilibrium structure and the potential energy functions of the ground state (X^2∑^+) and the low lying excited electronic state (A^2Л) of CN radical are calculated by using CASSCF method. The potential energy curves are obtained by a least square fitting to the modified Murrell-Sorbie function. On the basis of physical theory of potential energy function, harmonic frequency (ωe) and other spectroscopic constants (ωeχe, βe and αe) are calculated by employing the Rydberg-Klei-Rees method. The theoretical calculation results are in excellent agreement with the experimental and other complicated theoretical calculation data. In addition, the eigenvalues of vibrational levels have been calculated by solving the radial one-dimensional SchrSdinger equation of nuclear motion using the algebraic method based on the analytical potential energy function. 展开更多
关键词 potential energy function harmonic frequency vibrational levels algebraic method
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Analytical Potential Energy Function,Spectroscopic Constants and Vibrational Levels for A^1E_u^+ State of Dimer ~7Li_2 被引量:1
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作者 SHI De-Heng~1 MA Heng~1 SUN Jin-Feng~(1,2)and ZHU Zun-Lue~1~1 College of Physics & Information Engineering,Henan Normal University,Xinxiang 453007,China~2 Department of Physics & Electron Science,Luoyang Normal University,Luoyang 471022,China 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第12期1081-1087,共7页
The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2(A^1∑_u^+) over the internuclear distance ranging from 2.4ao to 37ao.The complete potential ene... The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2(A^1∑_u^+) over the internuclear distance ranging from 2.4ao to 37ao.The complete potential energycurves are calculated at numbers of basis sets.All the ab initio calculated points are fitted to the analytic MurrellSorbie function and then employed to compute the spectroscopic constants.By comparison,the spectroscopic constantsreproduced by the potential attained at D95(3df,3pd) are found to be very close to the experiments,a^d the values (T_e,D_e,R_e,ω_e,ω_eχ_e,α_e and B_e) are of 1.732 93 eV,1.161 36 eV,0.313 27 nm,251.95 cm^(-1),1.623 cm^(-1),0.005 35 cm^(-1),and0.490 cm^(-1),respectively.With the potential obtained at D95(3df,3pd),the totally 75 vibrational states are found whenJ=0.The vibrational levels,the classical turning points and the inertial rotation constants of the first 68 vibrationalstates are calculated for the first time and compared with the available measurements.Good agreement is obtained.The centrifugal distortion constants of the first 32 vibrational states are also reported for the first time.The reasonabledissociation limit for ~7Li_2(A^1∑_u^+) is deduced using the calculated results at present. 展开更多
关键词 analytic potential energy function harmonic frequency dissociation energy vibrational level classical turning point
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Surface and Content Validity of the Mentoring Function Scale for Novice Nurses
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作者 Aimi Furukawa Yasuko Hosoda 《Open Journal of Nursing》 2024年第8期401-411,共11页
This study aimed to examine the surface and content validity of the Mentoring Function Scale for Novice Nurses, used to assess the mentoring of entry-level nurses, and to refine the scale items. In Study 1, six nurse ... This study aimed to examine the surface and content validity of the Mentoring Function Scale for Novice Nurses, used to assess the mentoring of entry-level nurses, and to refine the scale items. In Study 1, six nurse education researchers, selected using convenience sampling, with five or more years of nursing experience and experience teaching novice nurses, were invited to an expert meeting in July 2015. A group interview was conducted that lasted approximately 120 minutes. Study 2 examined the content validity index. Between September and November 2015, we distributed a self-administered questionnaire survey to 11 participants selected by convenience sampling. The participants included five nurse education researchers with a minimum of five years of nursing experience and experience teaching novice nurses, as well as six clinical nurses with a master’s degree or higher. Finally, 81 questionnaire items were retained from the initial 125 items. The 81-item Mentoring Function Scale for Novice Nurses had higher content validity than the original scale. To further increase the scale’s applicability, future studies should assess its reliability, construct validity, and criterion-related validity. 展开更多
关键词 Novice Nurses Mentoring function Surface and Content Validity Item-level Content Validity Index
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Level set函数重新初始化的并行快速步进法 被引量:4
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作者 黄筱云 董国海 +1 位作者 赵利平 程永舟 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2016年第5期666-671,689,共7页
为提高level set函数重新初始化的计算效率,基于分区并行思想,提出一种快速步进法的并行策略,实现level set函数的快速并行重新初始化。通过对圆球、五叶管和圆环管等算例的level set函数重新初始化,讨论了新并行算法的准确性和效率。... 为提高level set函数重新初始化的计算效率,基于分区并行思想,提出一种快速步进法的并行策略,实现level set函数的快速并行重新初始化。通过对圆球、五叶管和圆环管等算例的level set函数重新初始化,讨论了新并行算法的准确性和效率。结果表明,与串行快速步进法相比,并行算法保留了串行算法的精度,仍基本保持在1阶左右,同时显著减少了重新初始化的计算时间,特别在8线程条件下,所获的最佳加速比能够达到5。 展开更多
关键词 level set函数 重新初始化 快速步进法 并行 分区 并行算法 加速比
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Level set函数快速步进重构并行算法的改进 被引量:4
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作者 黄筱云 董国海 +1 位作者 常佳夫 蒋学炼 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2017年第6期836-842,共7页
为提高level set函数快速步进重构过程的并行计算效率,本文提出一种改进的分区并行重构算法。与原有分区并行算法相比,优化了子区域间的同步方案,缩短了level set函数并行重构的计算时间。运用OpenMP多线程技术,建立了相应的并行计算模... 为提高level set函数快速步进重构过程的并行计算效率,本文提出一种改进的分区并行重构算法。与原有分区并行算法相比,优化了子区域间的同步方案,缩短了level set函数并行重构的计算时间。运用OpenMP多线程技术,建立了相应的并行计算模型,实现了圆球、圆环管和哑铃等值面并行重构。并行重构数值结果表明:只要子区域均分初始表面边界,level set函数全局或局部并行重构均具有良好加速比,8线程的最大加速比可接近6。 展开更多
关键词 level set函数 快速步进法 重构 并行算法 多线程技术 OpenMP多线程技术
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基于变分Level Set方法的图像分割 被引量:3
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作者 王文杰 封建湖 《计算机工程与应用》 CSCD 北大核心 2006年第18期68-70,共3页
文章主要利用levelset函数隐式地追踪图像的边界来实现图像分割。在该文中首先给出了一个变分问题以及相应的Euler-Lagrange方程,并且提出了一种求解该方程的数值算法,使得计算速度有了很大的提高。数值算例表明,该水平集算法具有数值... 文章主要利用levelset函数隐式地追踪图像的边界来实现图像分割。在该文中首先给出了一个变分问题以及相应的Euler-Lagrange方程,并且提出了一种求解该方程的数值算法,使得计算速度有了很大的提高。数值算例表明,该水平集算法具有数值稳定性,不会出现振荡现象,可以很好地处理拓扑结构的变化。 展开更多
关键词 图像处理 level SET方法 level set函数 图像分割
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Level set函数快速步进并行重构的分区优化 被引量:1
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作者 夏波 黄筱云 +2 位作者 陈同庆 程永舟 江诗群 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2019年第9期1601-1607,共7页
为进一步提升Level set函数重构的分区并行重构效率,本文采用均分交界面方式进行分区,并保证生成内边界重构节点数量最少。通过运用基于共享存储并行编程(OpenMP)多线程技术的并行计算模型,实现圆球、Zalesak球和哑铃等值面的并行重构... 为进一步提升Level set函数重构的分区并行重构效率,本文采用均分交界面方式进行分区,并保证生成内边界重构节点数量最少。通过运用基于共享存储并行编程(OpenMP)多线程技术的并行计算模型,实现圆球、Zalesak球和哑铃等值面的并行重构。计算结果表明:新分区方法能平衡子区域间计算荷载,减少子区域间信息传递次数和节点回滚次数,与均分区域方法相比,新分区方法能够获得更高计算速度,具有更好的实用性和可扩展性。 展开更多
关键词 level set函数 快速步进法 并行重构 分区优化 交界面 共享存储并行编程 多线程技术 加速比
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甲状腺功能水平与肌少症相关特征表型的关联
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作者 李嘉彤 金玥 +3 位作者 刘润嘉 宋博文 朱晓倩 李念虎 《中国组织工程研究》 CAS 北大核心 2025年第6期1312-1320,共9页
背景:多项观察性研究发现甲状腺功能水平与肌少症之间存在密切关系,但是甲状腺功能水平与肌少症发病之间的因果关系尚不明确。目的:采用两样本孟德尔随机化方法研究甲状腺功能水平与肌少症的因果关系。方法:利用促甲状腺激素、游离三碘... 背景:多项观察性研究发现甲状腺功能水平与肌少症之间存在密切关系,但是甲状腺功能水平与肌少症发病之间的因果关系尚不明确。目的:采用两样本孟德尔随机化方法研究甲状腺功能水平与肌少症的因果关系。方法:利用促甲状腺激素、游离三碘甲状腺原氨酸、游离四碘甲状腺原氨酸、亚临床甲状腺功能亢进症、亚临床甲状腺功能减退症和肌少症的4种相关表型——左手握力、右手握力、四肢瘦体质量、步速的全基因组关联研究汇总数据进行两样本孟德尔随机化分析,分别采用逆方差加权法、加权中位数法、简单模式法、加权中值方法和MR-Egger回归法作为分析方法,同时采用异质性检验、多效性检验、MR-PRESSO、留一法、漏斗图等方法进行敏感性分析。结果与结论:促甲状腺激素的增高会增加左手握力(β=0.02,SE=0.01,P=0.01)、右手握力(β=0.02,SE=0.01,P=0.01),游离三碘甲状腺原氨酸的增高会降低左手握力(β=-0.06,SE=0.02,P=9.5×10^(-5))、右手握力(β=-0.07,SE=0.02,P=9.3×10^(-5)),亚临床甲状腺功能亢进症会降低步速(β=-4.4×10^(-3),SE=1.7×10^(-3),P=0.01)。敏感性分析结果与主要分析基本一致。结果表明:促甲状腺激素上升是肌少症保护因素,游离三碘甲状腺原氨酸上升和亚临床甲状腺功能亢进症可能导致肌少症发生风险增加。 展开更多
关键词 孟德尔随机化 因果关系 甲状腺功能 促甲状腺激素 游离三碘甲状腺原氨酸 肌少症
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材料界面运动的Level Set算法 被引量:1
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作者 王振海 张卫红 +1 位作者 封建湖 蔡力 《工程数学学报》 CSCD 北大核心 2004年第F12期73-77,共5页
多材料结构中材料界面的变形运动在几何上可以抽象为闭曲线或闭曲面随时间的演化。本文导出了材料界面演化过程的隐函数描述,得到了材料界面运动所满足的Halmilton-Jacobi.方程,并且采用数值粘性最小,捕捉函数奇异性的能力最强的Goduno... 多材料结构中材料界面的变形运动在几何上可以抽象为闭曲线或闭曲面随时间的演化。本文导出了材料界面演化过程的隐函数描述,得到了材料界面运动所满足的Halmilton-Jacobi.方程,并且采用数值粘性最小,捕捉函数奇异性的能力最强的Godunov格式来求解。从而将材料界面演化变形的LevelSet算法归纳为初始化,速度扩展、材科界面变形计算与重新新初始化并循环迭代计算四部分。为了消除界面变形所产生的振荡现象,本文还给出了平均曲率流算法,可以对界面具有平滑怍用,快速消除界面中达到高曲率部分,减小界面的几何长度,使界面趋于光顺,并尽可能保持LevelSet函数的零等值线的平均位置不变。最后给出了两个LevelSet数值算例,说明了本文方法是有效的。 展开更多
关键词 界面运动 闭曲面 数值算例 平均曲率 隐函数 Godunov格式 循环迭代 算法 初始化 光顺
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用Level Set算法模拟孤立波与前台阶的相互作用 被引量:1
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作者 谢伟松 陶建华 《应用数学和力学》 EI CSCD 北大核心 2000年第7期686-692,共7页
进一步研究了Level Set方法的数学基础 ,研究了求解有自由水面水动力学问题的具体方法· 并在此基础上 ,对孤立波与前台阶相互作用这一问题进行了计算及研究 。
关键词 level-Set方法 孤立波 前台阶 相互作用 水动力
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