983 resultados para simple timing task


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本文以863-512型号项目为背景,从运动特性、运动描述、运动控制以及运动规划等几个方面研究履带式移动机器人的行动规划技术;首先从理论上分析了履带式移动机器人的内在运动传递机理,指出了其区别于轮式移动载体的独特的运动特性,尤其是在其转向特性方面,得出了履带式移动机器人运动角速度几乎不可控原理、原地转弯转不准问题、以及履带式车辆行动规划时所要遵循的规则等重要结论,针对履带式移动机器人的纵向运动控制问题,讨论了其速度控制模型,提出了一种速度测量与控制的简单、准确、可靠的方法。在磺向运动方面,提出了一种基于FM-LIKE和AM-LIKE相结合的复合控制技术,解决了难度较大的方向控制问题。最后提供了实验结果,证明了上述方法与结论的正确性。上述方法与结论,作为863-512某型号任务的一部分,业已通过验收。

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On 70~(th) SEG Annual meeting, many author have announced their result on the wave equation prestack depth migration. The methods of the wave-field imaging base on wave equation becomes mature and the main direction of seismic imaging. The direction of imaging the complex media has been the main one of the projects that the national "85" and "95" reservoir geophysics key projects and "Knowledge innovation key project of Chinese Academy of Science" have been supported. Furthermore, we began the study for special oil field situation of our nation with the international research groups. Under the background, the author combined the thoughts of symplectic with wave equation pre-stack depth migration, and develops and efficient wave equation pre-stack depth migration method. The purpose of this work is to find out a way to imaging the complex geological goals of Chinese oilfields and form a procedure of seismic data processing. The paper gives the approximation of one way wave equation operator, and shows the numerical results. The comparisons have been made between split-step phase method, Kirchhoff and Ray+FD methods on the pulse response, simple model and Marmousi model. The results shows that the method in this paper has an higher accuracy. Four field data examples have also be given in this paper. The results of field data demonstrate that the method can be usable. The velocity estimation is an important part of the wave equation pre-stack depth migration. A parallel velocity estimation program has been written and tested on the Beowulf clusters. The program can establish a velocity profile automatically. An example on Marmousi model has shown in the third part of the paper to demonstrate the method. Another field data was also given in the paper. Beowulf cluster is the converge of the high performance computer architecture. Today, Beowulf Cluster is a good choice for institutes and small companies to finish their task. The paper gives some comparison results the computation of the wave equation pre-stack migration on Beowulf cluster, IBM-SP2 (24 nodes) in Daqing and Shuguang 3000, and the comparison of their prize. The results show that the Beowulf cluster is an efficient way to finish the large amount computation of the wave equation pre-stack depth migration, especially for 3D.

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On 70~(th) SEG Annual meeting, many author have announced their result on the wave equation pre-stack depth migration. The methods of the wave-field imaging base on wave equation becomes mature and the main direction of seismic imaging. The direction of imaging the complex media has been the main one of the projects that the national "85" and "95" reservoir geophysics key projects and "Knowledge innovation key project of Chinese Academy of Science" have been supported. Furthermore, we began the study for special oil field situation of our nation with the international research groups. Under the background, the author combined the thoughts of symplectic with wave equation pre-stack depth migration, and develops and efficient wave equation pre-stack depth migration method. The purpose of this work is to find out a way to imaging the complex geological goals of Chinese oilfields and form a procedure of seismic data processing. The paper gives the approximation of one way wave equation operator, and shows the numerical results. The comparisons have been made between split-step phase method, Kirchhoff and Ray+FD methods on the pulse response, simple model and Marmousi model. The result shows that the method in this paper has an higher accuracy. Four field data examples have also be given in this paper. The results of field data demonstrate that the method can be usable. The velocity estimation is an important part of the wave equation pre-stack depth migration. A. parallel velocity estimation program has been written and tested on the Beowulf clusters. The program can establish a velocity profile automatically. An example on Marmousi model has shown in the third part of the paper to demonstrate the method. Another field data was also given in the paper. Beowulf cluster is the converge of the high performance computer architecture. Today, Beowulf Cluster is a good choice for institutes and small companies to finish their task. The paper gives some comparison results the computation of the wave equation pre-stack migration on Beowulf cluster, IBM-SP2 (24 nodes) in Daqing and Shuguang3000, and the comparison of their prize. The results show that the Beowulf cluster is an efficient way to finish the large amount computation of the wave equation pre-stack depth migration, especially for 3D.

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Seismic exploration is the main tools of exploration for petroleum. as the society needs more petroleum and the level of exploration is going up, the exploration in the area of complex geology construction is the main task in oil industry, so the seismic prestack depth migration appeared, it has good ability for complex construction imaging. Its result depends on the velocity model strongly. So for seismic prestack depth migration has become the main research area. In this thesis the difference in seismic prestack depth migration between our country and the abroad has been analyzed in system. the tomographical method with no layer velocity model, the residual curve velocity analysical method based on velocity model and the deleting method in pre-processing have been developed. In the thesis, the tomographysical method in velocity analysis is been analyzed at first. It characterized with perfection in theory and diffculity in application. This method use the picked first arrivial, compare the difference between the picked first arrival and the calculated arrival in theory velocity model, and then anti-projected the difference along the ray path to get the new velocity model. This method only has the hypothesis of high frequency, no other hypothesis. So it is very effective and has high efficiency. But this method has default still. The picking of first arrival is difficult in the prestack data. The reasons are the ratio of signal to noise is very low and many other event cross each other in prestack data. These phenomenon appear strongly in the complex geology construction area. Based on these a new tomophysical methos in velocity analysis with no layer velocity model is been developed. The aim is to solve the picking problem. It do not need picking the event time contiunely. You can picking in random depending on the reliability. This methos not only need the pick time as the routine tomographysical mehtod, but also the slope of event. In this methos we use the high slope analysis method to improve the precision of picking. In addition we also make research on the residual curve velocity analysis and find that its application is not good and the efficiency is low. The reasons is that the hypothesis is rigid and it is a local optimizing method, it can solve seismic velocity problem in the area with laterical strong velocity variation. A new method is developed to improve the precision of velocity model building . So far the pattern of seismic prestack depth migration is the same as it aborad. Before the work of velocity building the original seismic data must been corrected on a datum plane, and then to make the prestack depth migration work. As we know the successful example is in Mexico bay. It characterized with the simple surface layer construction, the pre-precessing is very simple and its precision is very high. But in our country the main seismic work is in land, the surface layer is very complex, in some area the error of pre-precessing is big, it affect the velocity building. So based on this a new method is developed to delete the per-precessing error and improve the precision of velocity model building. Our main work is, (1) developing a effective tomographical velocity building method with no layer velocity model. (2) a new high resolution slope analysis method is developed. (3) developing a global optimized residual curve velocity buliding method based on velocity model. (4) a effective method of deleting the pre-precessing error is developing. All the method as listed above has been ceritified by the theorical calculation and the actual seismic data.

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A simple and sensitive method for the determination of short and long-chain fatty acids using high-performance liquid chromatography with fluorimetric detection has been developed. The fatty acids were derivatized to their corresponding esters with 9-(2-hydroxyethyl)-carbazole (HEC) in acetonitrile at 60 degreesC with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride as a coupling agent in the presence of 4-dimethylaminopyridine (DMAP). A mixture of esters of C-1-C-20 fatty acids was completely separated within 38 min in conjunction with a gradient elution on a reversed-phase C-18 column. The maximum fluorescence emission for the derivatized fatty acids is at 365 nm (lambda (ex) 335 nm). Studies on derivatization conditions indicate that fatty acids react proceeded rapidly and smoothly with HEC in the presence of EDC and DMAP in acetonitrile to give the corresponding sensitively fluorescent derivatives. The application of this method to the analysis of long chain fatty acids in plasma is also investigated. The LC separation shows good selectivity and reproducibility for fatty acids derivatives. The R.S.D. (n = 6) for each fatty acid derivative are <4%. The detection limits are at 45-68 fmol levels for C-14-C-20 fatty acids and even lower levels for

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The purpose of this study is to investigate the influence of attention resourse requirement and allocation on implicit memory and explicit memory for object-location associations in driving situation based on Adams theory on the function of implicit knowledge in the Situation Awareness(SA). This study adopted Musen’s implicit learning of object-location associations, sysmemtly manipulated the type and difficuty of the naming task. This research includes three studies and ten experiments. Their aim are separately to explore the influence of attention on implicit and explicit memory for object-loction assocaitons in simple stimulus and the driving situation. And it is needed to confirme the condition and the influencing factors of implicit memory for car-location association in different condition. It is also our aim to explore the feasibility of introduce of implicit learning methods in SA measurement. The results indicted that: ⑴ The influence of attention resourse allocation ,the difficulty of naming task , the deepness of processing on on implicit memory for object-location associations in driving situation are different . the dissociated results support the standpoint that there are two independent knowledge system; ⑵ The type of naming task more influenced the implicit and explicit memory for object-location associations than the difficulty of the naming task. The attention resourse requirement of the different type can not be compared; ⑶ The implicit memory seldom appears in the location naming task resulted from the defiency of processing on object-location association, and not as a results of the overtaxed; ⑷ The reaction time methods in the implicit learning could be used in SA measurement , it is a complementarity of the existing explicit SA measurement. These findings not only contribute to resolve ongoing debates about the process of cognition and mechanism of SA structure, but also have significant practical application in traffic safety.

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It is well established that memory functioning deteriorates with advancing age. However, research indicates that the magnitude of age-related memory deficits varies across different types of memory, and broad individual differences can be observed in the rate and timing of memory aging. The general aim of this study was to investigate the selectivity and variability of memory functioning in relation to anxiety. Firstly, memory effectiveness was assessed in episodic memory tasks with reality monitoring and external source monitoring paradigms, semantic memory tasks referred to general knowledge and word fluency, and perceptual priming task reflected in word completion. According to the scores on trait version of STAI, the high-trait and low-trait anxious subjects were screened respectively from young and old participants matched for educational level. Secondly, based on the results of the first part, concurrent primary and secondary tasks with probe technique assessing spare processing capacity were used to explore the relation between memory efficiency and anxiety. The first main findings were that: (a) there were no age-related differences in semantic memory assessed by general knowledge and PRS, whereas age effects were observed in episodic memory and semantic memory assessed by word fluency with stringent time restraints. (b) Furthermore, comparison of age-related deficits in source and item was not related to the presentation ways and encoding effort for source, but was affected by types of source. Specifically, memory was more sensitive to aging than item memory in external source monitoring processes involved in discriminating two external sources (i.e., female vs. male voices), but not in reality monitoring processes in discriminating between internal and external sources (i.e., acting vs. listening). The second main findings were that: (a) Anxiety had no effects on the effectiveness and efficiency of semantic memory in recall of general knowledge and PRS, but impaired those of semantic memory in word fluency. (b) The effects of anxiety on episodic memory were different between the old and the young. Both the effectiveness and the efficiency of episodic memory of the old were affected adversely by anxiety. More importantly, source recall in external source monitoring processes was observed to be more vulnerable to anxiety than item memory. The effectiveness of episodic memory of the young was relatively unrelated to anxiety, while anxiety might have adverse effect on their memory efficiency. These results indicated that: First, the selectivity of age-related memory deficits existed not only between memory systems, but also within episodic memory system. The tendency to forget the source even when the fact was retained in external source monitoring was suggested to be a specific feature of cognitive aging. Second, anxiety had adverse impact on the individual differences in memory aging, and mediated partial age-related differences in episodic memory performance.

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The time-courses of orthographic, phonological and semantic processing of Chinese characters were investigated systematically with multi-channel event-related potentials (ERPs). New evidences concerning whether phonology or semantics is processed first and whether phonology mediates semantic access were obtained, supporting and developing the new concept of repetition, overlapping, and alternating processing in Chinese character recognition. Statistic parameter mapping based on physiological double dissociation has been developed. Seven experiments were conducted: I) deciding which type of structure, left-right or non-left-right, the character displayed on the screen was; 2) deciding whether or not there was a vowel/a/in the pronunciation of the character; 3) deciding which classification, natural object or non-natural object, the character was; 4) deciding which color, red or green, the character was; 5) deciding which color, red or green, the non-character was; 6) fixing on the non-character; 7) fixing on the crosslet. The main results are: 1. N240 and P240:N240 and P240 localized at occipital and prefrontal respectively were found in experiments 1, 2, 3, and 4, but not in experiments 5, 6, or 7. The difference between the former 4 and the latter 3 experiments was only their stimuli: the former's were true Chinese characters while the latter's were non-characters or crosslet. Thus Chinese characters were related to these two components, which reflected unique processing of Chinese characters peaking at about 240 msec. 2. Basic visual feature analysis: In comparison with experiment 7 there was a common cognitive process in experiments 1, 2, 4, and 6 - basic visual feature analysis. The corresponding ERP amplitude increase in most sites started from about 60 msec. 3. Orthography: The ERP differences located at the main processing area of orthography (occipital) between experiments 1, 2, 3, 4 and experiment 5 started from about 130 msec. This was the category difference between Chinese characters and non-characters, which revealed that orthographic processing started from about 130 msec. The ERP differences between the experiments 1, 2, 3 and the experiment 4 occurred in 210-250, 230-240, and 190-250 msec respectively, suggesting orthography was processed again. These were the differences between language and non-language tasks, which revealed a higher level processing than that in the above mentioned 130 msec. All the phenomena imply that the orthographic processing does not finished in one time of processing; the second time of processing is not a simple repetition, but a higher level one. 4. Phonology: The ERPs of experiment 2 (phonological task) were significantly stronger than those of experiment 3 (semantic task) at the main processing areas of phonology (temporal and left prefrontal) starting from about 270 msec, which revealed phonologic processing. The ERP differences at left frontal between experiment 2 and experiment 1 (orthographic task) started from about 250 msec. When comparing phonological task with experiment 4 (character color decision), the ERP differences at left temporal and prefrontal started from about 220 msec. Thus phonological processing may start before 220 msec. 5. Semantic: The ERPs of experiment 3 (semantic task) were significantly stronger than those of experiment 2 (phonological task) at the main processing areas of semantics (parietal and occipital) starting from about 290 msec, which revealed semantic processing. The ERP differences at these areas between experiment 3 and experiment 4 (character color decision) started from about 270 msec. The ERP differences between experiment 3 and experiment 1 (orthographic task) started from about 260 msec. Thus semantic processing may start before 260 msec. 6. Overlapping of phonological and semantic processing: From about 270 to 350 msec, the ERPs of experiment 2 (phonological task) were significantly larger than those of experiment 3 (semantic task) at the main processing areas of phonology (temporal and left prefrontal); while from about 290-360 msec, the ERPs of experiment 3 were significantly larger than those of experiment 2 at the main processing areas of semantics (frontal, parietal, and occipital). Thus phonological processing may start earlier than semantic and their time-courses may alternate, which reveals parallel processing. 7. Semantic processing needs part phonology: When experiment 1 (orthographic task) served as baseline, the ERPs of experiment 2 and 3 (phonological and semantic tasks) significantly increased at the main processing areas of phonology (left temporal and frontal) starting from about 250 msec. The ERPs of experiment 3, besides, increased significantly at the main processing areas of semantics (parietal and frontal) starting from about 260 msec. When experiment 4 (character color decision) served as baseline, the ERPs of experiment 2 and 3 significantly increased at phonological areas (left temporal and frontal) starting from about 220 msec. The ERPs of experiment 3, similarly, increased significantly at semantic areas (parietal and frontal) starting from about270 msec. Hence, before semantic processing, a part of phonological information may be required. The conclusion could be got from above results in the present experimental conditions: 1. The basic visual feature processing starts from about 60 msec; 2. Orthographic processing starts from about 130 msec, and repeats at about 240 msec. The second processing is not simple repetition of the first one, but a higher level processing; 3. Phonological processing begins earlier than semantic, and their time-courses overlap; 4. Before semantic processing, a part of phonological information may be required; 5. The repetition, overlapping, and alternating of the orthographic, phonological and semantic processing of Chinese characters could exist in cognition. Thus the problem of whether phonology mediates semantics access is not a simple, but a complicated issue.