• Title/Summary/Keyword: LTM

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The Effect of the Number of Vibration Modes on the Application of the Location Template Matching(LTM) Method (Location Template Matching(LTM) 방법을 적용함에 있어서 진동 모드 수의 영향)

  • Shin, Kihong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.2
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    • pp.172-178
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    • 2016
  • The location template matching (LTM) method is a technique of identifying an impact location on a structure, and is often applied to structural health monitoring and large scale human-computer interface (HCI) systems. The LTM method utilizes a certain measure of similarity between two time signals. The correlation coefficient is most widely used for this purpose, and the group delay based method is recently proposed to improve the accuracy of finding the best matching pair of signals. In practice, one of key essential consideration for implementing the LTM method is to guarantee that a sufficient number of vibration modes must be contained in the measured signal, and yet the lower sampling rate is needed for a real-time implementation. In this paper, the properties of correlation coefficient and group delay with respect to the number of vibration modes are investigated. A few important results are obtained through extensive computer simulations and experiments. If the number of vibration modes contained in the measured signal is more than four it is sufficient for the correlation based LTM method, while the group delay based LTM method requires smaller number of vibration modes.

An alternative approach to extruding a vertically impacted lower third molar using an orthodontic miniscrew: A case report with cone-beam CT follow-up

  • Cortes, Arthur Rodriguez Gonzalez;No-Cortes, Juliana;Cavalcanti, Marcelo Gusmao Paraiso;Arita, Emiko Saito
    • Imaging Science in Dentistry
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    • v.44 no.2
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    • pp.171-175
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    • 2014
  • One of the most common oral surgical procedures is the extraction of the lower third molar (LTM). Postoperative complications such as paresthesia due to inferior alveolar nerve (IAN) injury are commonly observed in cases of horizontal and vertical impaction. The present report discusses a case of a vertically impacted LTM associated with a dentigerous cyst. An intimate contact between the LTM roots and the mandibular canal was observed on a panoramic radiograph and confirmed with cone-beam computed tomographic (CBCT) cross-sectional cuts. An orthodontic miniscrew was then used to extrude the LTM prior to its surgical removal in order to avoid the risk of inferior alveolar nerve injury. CBCT imaging follow-up confirmed the success of the LTM orthodontic extrusion.

Sensory Motor Coordination System for Robotic Grasping (로봇 손의 힘 조절을 위한 생물학적 감각-운동 협응)

  • 김태형;김태선;수동성;이종호
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.2
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    • pp.127-134
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    • 2004
  • In this paper, human motor behaving model based sensory motor coordination(SMC) algorithm is implemented on robotic grasping task. Compare to conventional SMC models which connect sensor to motor directly, the proposed method used biologically inspired human behaving system in conjunction with SMC algorithm for fast grasping force control of robot arm. To characterize various grasping objects, pressure sensors on hand gripper were used. Measured sensory data are simultaneously transferred to perceptual mechanism(PM) and long term memory(LTM), and then the sensory information is forwarded to the fastest channel among several information-processing flows in human motor system. In this model, two motor learning routes are proposed. One of the route uses PM and the other uses short term memory(STM) and LTM structure. Through motor learning procedure, successful information is transferred from STM to LTM. Also, LTM data are used for next moor plan as reference information. STM is designed to single layered perception neural network to generate fast motor plan and receive required data which comes from LTM. Experimental results showed that proposed method can control of the grasping force adaptable to various shapes and types of greasing objects, and also it showed quicker grasping-behavior lumining time compare to simple feedback system.

Evaluation of Streptomyces saraciticas as Soil Amendments for Controlling Soil-Borne Plant Pathogens

  • Wu, Pei-Hsuan;Tsay, Tung-Tsuan;Chen, Peichen
    • The Plant Pathology Journal
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    • v.37 no.6
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    • pp.596-606
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    • 2021
  • Soil-borne diseases are the major problems in mono cropping. A mixture (designated LTM-m) composed of agricultural wastes and a beneficial microorganism Streptomyces saraceticus SS31 was used as soil amendments to evaluate its efficacy for managing Rhizoctonia solani and root knot nematode (Meloidogyne incognita). In vitro antagonistic assays revealed that SS31 spore suspensions and culture broths effectively suppressed the growth of R. solani, reduced nematode egg hatching, and increased juvenile mortality. Assays using two Petri dishes revealed that LTM-m produced volatile compounds to inhibit the growth of R. solani and cause mortality to the root knot nematode eggs and juveniles. Pot and greenhouse tests showed that application of 0.08% LTM-m could achieve a great reduction of both diseases and significantly increase plant fresh weight. Greenhouse trials revealed that application of LTM-m could change soil properties, including soil pH value, electric conductivity, and soil organic matter. Our results indicate that application of LTM-m bio-organic amendments could effectively manage soil-borne pathogens.

Comparative Study on the Measures of Similarity for the Location Template Matching(LTM) Method (Location Template Matching(LTM) 방법에 사용되는 유사성 척도들의 비교 연구)

  • Shin, Kihong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.4
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    • pp.310-316
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    • 2014
  • The location template matching(LTM) method is a technique of identifying an impact location on a structure, and requires a certain measure of similarity between two time signals. In general, the correlation coefficient is widely used as the measure of similarity, while the group delay based method is recently proposed to improve the accuracy of the impact localization. Another possible measure is the frequency response assurance criterion(FRAC), though this has not been applied yet. In this paper, these three different measures of similarity are examined comparatively by using experimental data in order to understand the properties of these measures of similarity. The comparative study shows that the correlation coefficient and the FRAC give almost the same information while the group delay based method gives the shape oriented information that is best suitable for the location template matching method.

Comparative Study on the Measures of Similarity for the Location Template Matching (LTM) Method (Location Template Matching(LTM) 방법에 사용되는 유사성 척도들의 비교 연구)

  • Shin, Kihong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.04a
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    • pp.506-511
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    • 2014
  • The location template matching (LTM) method is a technique of identifying an impact location on a structure, and requires a certain measure of similarity between two time signals. In general, the correlation coefficient is widely used as the measure of similarity, while the group delay based method is recently proposed to improve the accuracy of the impact localization. Another possible measure is the frequency response assurance criterion (FRAC), though this has not been applied yet. In this paper, these three different measures of similarity are examined comparatively by using experimental data in order to understand the properties of these measures of similarity. The comparative study shows that the correlation coefficient and the FRAC give almost the same information while the group delay based method gives the shape oriented information that is best suitable for the location template matching method.

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Modeling the human memory in nerve fields

  • Fujita, Osamu;Kakazu, Yukinori
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.70-73
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    • 1992
  • This paper describes the modeling of human memory using a nerve field model which is proposed for modeling the mechanism of brain mathematically. In our model, two phases of memory, retention and recollection, are focused on. The former consists of two stages, short-term memory (STM) and long-term memory (LTM). The proposed model consists of three parts, the STM Layer, LTM Layer and the Intermediate Layer between them. Each of these is constructed by a nerve field. In the STM Layer, memorized information is retained dynamically in the form of the reverberating states of units within the layer, while in the LTM Layer, it is stored statically in the form of structures of the weight on the links between units. the Intermediate Layer is introduced to translate this dynamic representation in the STM Layer to the LTNI Layer, and also to extract the static information from the STM Layer. In addition to this, we consider the recollection of information stored in the LTM. Finally, the behavior of this model is demonstrated by computer simulation.

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Elucidating Bottlenecks to the Efficient Preparation of AB5-Hexamer Mucosal Adjuvant Protein LTm by Genetic Engineering

  • Liu, Di;Hu, Fabiao;Wang, Wenpeng;Wu, Dong;He, Xiujuan;Zheng, Wenyun;Liu, Haipeng;Ma, Xingyuan
    • Journal of Microbiology and Biotechnology
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    • v.27 no.8
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    • pp.1461-1471
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    • 2017
  • Escherichia coli heat-labile enterotoxin (LT) and its non-toxic mutant (LTm) are well-known powerful mucosal adjuvants and immunogens. However, the yields of these adjuvants from genetically engineered strains remain at extremely low levels, thereby hindering their extensive application in fundamental and clinical research. Therefore, efficient production of these adjuvant proteins from genetically engineered microbes is a huge challenge in the field of molecular biology. In order to explore the expression bottlenecks of LTm in E. coli, we constructed a series of recombinant plasmids based on various considerations and gene expression strategies. After comparing the protein expression among strains containing different recombinant plasmids, the signal sequence was found to be critical for the expression of LTm and its subunits. When the signal sequence was present, the strong hydrophobicity and instability of this amino acid sequence greatly restricted the generation of subunits. However, when the signal sequence was removed, abundantly expressed subunits formed inactive inclusion bodies that could not be assembled into the hexameric native form, although the inclusion body subunits could be refolded and the biological activity recovered in vitro. Therefore, the dilemma choice of signal sequence formed bottlenecks in the expression of LTm. These results reveal the expression bottlenecks of LTm, provide guidance for the preparation of LTm and its subunits, and certainly help to promote efficient preparation of this mucosal adjuvant protein.

Analysis of the Effect of the Grid Spacing on the Application of the Location Template Matching Method Using a Cantilever Beam (외팔 보를 이용한 Location Template Matching 방법을 적용함에 있어서 격자간격의 영향 분석)

  • Shin, Kihong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.5
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    • pp.609-615
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    • 2016
  • Measuring similarity between two signals is a key element of the location template matching (LTM) method which is one of impact source localization technique. As a measure of similarity, the correlation coefficient is most widely used, and the group delay based method is recently proposed to improve the accuracy of finding the impact source. In practice, the LTM method assumes that the similarity between two signals decreases as the distance between two corresponding impact points increases, where the distance between two neighboring impact points defines the grid spacing. In this paper, it is shown that this assumption is not always true but the correlation coefficients fluctuate forming a main robe and many side robes as the distance between two neighboring impact points increases. On the other hand, the standard deviation of group delay sharply increases with a small increase of the grid spacing. These are demonstrated by using a simple cantilever beam. Based on these findings, an optimal way of implementing the LTM method may be suggested by combining the correlation coefficient and the group delay based approaches.

Hybrid Tone Mapping Technique Considering Contrast and Texture Area Information for HDR Image Restoration (HDR 영상 복원을 위해 대비와 텍스쳐 영역 정보를 고려한 혼합 톤 매핑 기법)

  • Kang, Ju-Mi;Park, Dae-Jun;Jeong, Jechang
    • Journal of Broadcast Engineering
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    • v.22 no.4
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    • pp.496-508
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    • 2017
  • In this paper, we propose a Tone Mapping Operator (TMO) that preserves global contrast and precisely preserves boundary information. In order to reconstruct a High Dynamic Range (HDR) image to a Low Dynamic Range (LDR) display by using Threshold value vs. Intensity value (TVI) based on Human Visual System (HVS) and contrast value. As a result, the global contrast of the image can be preserved. In addition, by combining the boundary information detected using Guided Image Filtering (GIF) and the detected boundary information using the spatial masking of the Just Noticeable Difference (JND) model, And improved the perceived image quality of the output image. The conventional TMOs are classified into Global Tone Mapping (GTM) and Local Tone Mapping (LTM). GTM preserves global contrast, has the advantages of simple implementation and fast execution time, but it has a disadvantage in that the boundary information of the image is lost and the regional contrast is not preserved. On the other hand, the LTM preserves the local contrast and boundary information of the image well, but some areas are expressed unnatural like the occurrence of the halo artifact phenomenon in the boundary region, and the calculation complexity is higher than that of GTM. In this paper, we propose TMO which preserves global contrast and combines the merits of GTM and LTM to preserve boundary information of images. Experimental results show that the proposed tone mapping technique has superior performance in terms of cognitive quality.