A two-stage shape retrieval (TSR) method with global and local features

A robust two-stage shape retrieval (TSR) method is proposed to address the 2D shape retrieval problem. Most state-of-the-art shape retrieval methods are based on local features matching and ranking. Their retrieval performance is not robust since they may retrieve globally dissimilar shapes in high ranks. To overcome this challenge, we decompose the decision process into two stages. In the first irrelevant cluster filtering (ICF) stage, we consider both global and local features and use them to predict the relevance of gallery shapes with respect to the query. Irrelevant shapes are removed from the candidate shape set. After that, a local-features-based matching and ranking (LMR) method follows in the second stage. We apply the proposed TSR system to MPEG-7, Kimia99 and Tari1000 three datasets and show that it outperforms all other existing methods. The robust retrieval performance of the TSR system is demonstrated.     

基于PLC的自动化立体仓库实验系统的研制

自动化立体仓库是一种典型的机电一体化设备,对于机电一体化专业学生理解和掌握机电一体化系统设计及维护有着极大的帮助.介绍了基于PLC的自动化立体仓库实验系统的研制,该系统由机械本体、电气系统、PLC控制系统以及组态监控系统构成.装置研发成功后,已经在课程教学、实训以及毕业设计等环节得到了应用,取得了预期的效果.     

船舶铁舾件工时定额估算方法研究

为了解决人工工时估算不准确且费时等问题,准确测算船舶铁舾件舾装作业的工时定额,提出了基于CBR和BP神经网络的铁舾件装配工时定额制定方法.针对铁舾件细分工种安装工艺相似但型号各异的特点,提出基于非数值型和数值型特征参数相结合的相似性规律,在已知部分型号舾装工时情况下,利用相似性检索方法找出与新铁舾件最相似的铁舾件集,根...     

Retrieval during learning facilitates subsequent memory encoding.

In multiple-list learning, retrieval during learning has been suggested to improve recall of the single lists by enhancing list discrimination and, at test, reducing interference. Using electrophysiological, oscillatory measures of brain activity, we examined to what extent retrieval during learning facilitates list encoding. Subjects studied 5 lists of items in anticipation of a final cumulative recall test and did either a retrieval or a no-retrieval task between study of the lists. Retrieval was from episodic memory (recall of the previous list), semantic memory (generation of exemplars from an unrelated category), or short-term memory (2-back task). Behaviorally, all 3 forms of retrieval enhanced recall of both previously and subsequently studied lists. Physiologically, the results showed an increase of alpha power (8–14 Hz) from List 1 to List 5 encoding when no retrieval activities were interpolated but no such increase when any of the 3 retrieval activities occurred. Brain–behavior correlations showed that alpha-power dynamics from List 1 to List 5 encoding predicted subsequent recall performance. The results suggest that, without intermittent retrieval, encoding becomes ineffective across lists. In contrast, with intermittent retrieval, there is a reset of the encoding process for each single list that makes encoding of later lists as effective as encoding of early lists. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Encoding modality can affect memory accuracy via retrieval orientation.

Research indicates that false memory is lower following visual than auditory study, potentially because visual information is more distinctive. In the present study we tested the extent to which retrieval orientation can cause a modality effect on memory accuracy. Participants studied unrelated words in different modalities, followed by criterial recollection tests that selectively oriented retrieval toward one study modality at a time. Memory errors were lower when oriented toward visual than toward auditory information, thereby generalizing the modality effect to an explicit source memory task. Moreover, these effects persisted independent of the test presentation modality, indicating that retrieval orientation overrode the potential cuing properties of the test stimulus. An independent manipulation check confirmed that visual recollections were subjectively experienced as more distinctive than auditory recollections. These results suggest that retrieval orientation is sufficient to cause a modality effect on memory accuracy by focusing monitoring processes on the recollection of studied features that are diagnostic of prior presentation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interference from retrieval cues in Parkinson's disease.

Objective: Existing studies on memory interference in Parkinson's disease (PD) patients have provided mixed results and it is unknown whether PD patients have problems in overcoming interference from retrieval cues. We investigated this issue by using a part-list cuing paradigm. In this paradigm, after the study of a list of items, the presentation of some of these items as retrieval cues hinders the recall of the remaining ones. Method: We tested PD patients' (n = 19) and control participants' (n = 16) episodic memory in the presence and absence of part-list cues, using initial-letter probes, and following either weak or strong serial associative encoding of list items. Results: Both PD patients and control participants showed a comparable and significant part-list cuing effect after weak associative encoding (13% vs. 12% decrease in retrieval in part-list cuing vs. no part-list cuing -control- conditions in PD patients and control participants, respectively), denoting a similar effect of cue-driven interference in the two populations when a serial retrieval strategy is hard to develop. However, only PD patients showed a significant part-list cuing effect after strong associative encoding (20% vs. 5% decrease in retrieval in patients and controls, respectively). Conclusions: When encoding promotes the development of an effective serial retrieval strategy, the presentation of part-list cues has a specifically disruptive effect in PD patients. This indicates problems in strategic retrieval, probably related to PD patients' increased tendency to rely on external cues. Findings in control conditions suggest that less effective encoding may have contributed to PD patients' memory performance. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Experimental renewal in human participants.

Two experiments with human participants are presented that differentiate renewal from other behavioral effects that can produce a response after extinction. Participants played a video game and learned to suppress their behavior when sensor stimuli predicted an attack. Contexts (A, B, & C) were provided by fictitious galaxies where the game play took place. In Experiment 1, participants who received conditioning in A, extinction in B, and testing in A showed some context specificity of conditioning during extinction and a recovery of suppression on test. Experiment 2 demonstrated recovery of extinguished responding when participants were conditioned in A, extinguished in B, and tested in C, a third, neutral context. The experiment also demonstrated that the context of extinction did not control performance by becoming inhibitory. Results are discussed in terms of mechanisms that can produce a response recovery after extinction. The experiments demonstrated a renewal effect: a response recovery that was not attributable to the contexts acting as simple conditioned stimuli and is the first work with human participants to conclusively do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal memory in drug-naive, newly diagnosed Parkinson's disease. The retrieval deficit hypothesis revisited.

Objective: The retrieval deficit hypothesis on memory impairment in patients with Parkinson's disease (PD) implies a selective impairment in recall of learned material with normal encoding, retention, and recognition. This hypothesis has been challenged by new data. We have therefore investigated verbal memory and learning in a large sample of newly diagnosed, drug na?ve, non-demented patients with PD. Method: From a sample of patients with PD from the Norwegian ParkWest study, 133 PD patients and 133 controls matched on sex, age, and education were included. The California Verbal Learning Test-2 (CVLT-2) was used to assess verbal memory. Results: Patients performed significantly worse than controls on free and cued recall as well as on recognition memory. Patients used the semantic clustering learning strategy significantly less extensively than the controls and the learning slope of the PD patients was significantly less steep. There was no difference in retention when controlling for encoding. Patients did not perform better on the recognition measure or on cued recall (d-prime), as compared to free recall. Executive functions explained a substantial part of the memory deficits. Conclusions: This study suggests that memory impairment in drug na?ve early PD to a large degree is a deficit of learning/ encoding and not of retention or retrieval. An implication is that the retrieval deficit hypothesis should be moderated in its general form. Executive deficits and less extensive use of the efficient semantic clustering learning strategy had a strong impact on learning and memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

双阻带单负介质在带通滤波器中的应用

提出一种具有双阻带特性的单负介质并据此设计出小型化高性能的带通滤波器。首先对该单负介质单元进行等效电路分析并利用散射矩阵进行等效磁导率的提取,揭示了该异向介质单元的带阻工作原理和验证了其等效电路分析的合理性;然后在此基础上研究介质单元的结构参数对其传输性能的影响,据此设计出中心频率为10 GHz的带通滤波器具有非常紧凑的尺寸(25 mm×22.86 mm×10.16 mm)以及具有小于0.16 dB的通带损耗和良好的阻带抑制性能,这是常规介质滤波器所无法比拟的。     

基于PLC的自动化立体仓库系统设计

以自动化立体仓库系统的硬件组成为出发点,重点对其控制系统从硬件设计和软件设计两方面进行了深入研究.通过PROFIBUS现场总线将系统的监控机、上位机以及下位机连接成-个有机整体,同时应用工控组态软件组态王Kingview对系统进行监控,达到了远程实时监控和管理的目的.现场调试结果表明,该系统自动化程度较高,操作方便,工...