• Title/Summary/Keyword: measurement table

Search Result 455, Processing Time 0.028 seconds

An integrated visual-inertial technique for structural displacement and velocity measurement

  • Chang, C.C.;Xiao, X.H.
    • Smart Structures and Systems
    • /
    • v.6 no.9
    • /
    • pp.1025-1039
    • /
    • 2010
  • Measuring displacement response for civil structures is very important for assessing their performance, safety and integrity. Recently, video-based techniques that utilize low-cost high-resolution digital cameras have been developed for such an application. These techniques however have relatively low sampling frequency and the results are usually contaminated with noises. In this study, an integrated visual-inertial measurement method that combines a monocular videogrammetric displacement measurement technique and a collocated accelerometer is proposed for displacement and velocity measurement of civil engineering structures. The monocular videogrammetric technique extracts three-dimensional translation and rotation of a planar target from an image sequence recorded by one camera. The obtained displacement is then fused with acceleration measured from a collocated accelerometer using a multi-rate Kalman filter with smoothing technique. This data fusion not only can improve the accuracy and the frequency bandwidth of displacement measurement but also provide estimate for velocity. The proposed measurement technique is illustrated by a shake table test and a pedestrian bridge test. Results show that the fusion of displacement and acceleration can mitigate their respective limitations and produce more accurate displacement and velocity responses with a broader frequency bandwidth.

Study on the Separation Performance of a Tray-type Paddy Separator (트레이형 현립분리기의 분리성능에 관한 연구)

  • 정창주
    • Journal of Biosystems Engineering
    • /
    • v.5 no.1
    • /
    • pp.43-50
    • /
    • 1980
  • The milling plants in Korea have been generally used the paddy-separator that operated in accordance with the principle of sieving action. This type of paddy separator was considered as inefficient, especially in relation to the new high-yielding varieties which have different size characteristics within their varieties and also as compared to traditional varieties. With the installation of modern paddy separator it may be possible to increase the overall milling system efficiency and to reduce the grain loss. This study was intended to identify and define important parameters required for assessing the separation performance of a tray-type paddy separator and to determine the optimum conditions of the inclination of separator-table. The results of the study were summarized as follows : (1) Separation performance can be given by use of many parameters found from the measurement of separator outputs. such as upper-tail recovery $(\varepsilon)$, purity of upper-tail $(\gamma)$ , separation recovery of brown rice $(\alpha)$, separation recovery paddy $(\beta)$, and efficiency of separator $(\epsilon)$, Among these para-meters , $\varepsilon$, $\gamma$, $\alpha$ and $\beta$, were designated , respectively, their independent properties of the paddy separator. In addition, their modes of variation due to a varied inclination of the separation table did not indicated in the same direction . However, the efficiency of separator had an advantage to indicate the overall characteristics of the separator performance with a clear optimum inclination condition of the separator table. (2) The optimum feed rate and maximum efficiency of the separator did not occur at the identical inclination of the separator table. Thus, for its practical operation it is necessary to compromise between the qualitative and quantitative performances of the separator. (3) The optimum setting of the separator table tested in the study showed to occur at its inclination of approximately $26^\circ<$/TEX> for the front and $8^\circ<$/TEX> for lateral.

  • PDF

Comparison of Electromyography Activity in Accordance with Contact Pad Type during the Use of a Standing Table for Pediatric Patients with Brain Lesions (뇌병변 소아환자의 기립보조기 사용 시 접촉 패드 유형에 따른 근활성도 비교)

  • Lee, J.H.;Oh, M.W.;Ha, J.G.;Seo, J.Y.;Hwang, H.S.
    • Journal of rehabilitation welfare engineering & assistive technology
    • /
    • v.8 no.3
    • /
    • pp.161-168
    • /
    • 2014
  • This study conducted a comparative analysis of the contraction pattern of trunk and lower limbs muscles of handicapped children with brain lesions during the use of foam pad and air pad for fixing a standing table to the body for pediatric patients with brain lesions using a standing table product applied with a pneumatic air fitting system. There was a difference in the measurement of muscle strength activity by muscle in accordance with pad type (foam pad vs. air pad). A large difference was found with big movements (movements of eating), while a small difference was discovered with small movements (writing and reading movements). This was found to furnish a little more comfort to users compared with the existing foam pad during the use of a standing table product applied with a pneumatic air fitting system.

  • PDF

Modelling of noise-added saturated steam table using the neural networks (신경회로망을 사용한 노이즈가 첨가된 포화증기표의 모델링)

  • Lee, Tae-Hwan;Park, Jin-Hyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2008.05a
    • /
    • pp.205-208
    • /
    • 2008
  • In numerical analysis numerical values of thermodynamic properties such as temperature, pressure, specific volume, enthalpy and entropy are required. But most of the thermodynamic properties of the steam table are determined by experiment. Therefore they are supposed to have measurement errors. In order to make noised thermodynamic properties corresponding to errors, random numbers are generated, adjusted to appropriate magnitudes and added to original thermodynamic properties. the neural networks and quadratic spline interpolation method are introduced for function approximation of these modified thermodynamic properties in the saturated water based on pressure. It was proved that the neural networks give smaller percentage error compared with quadratic spline interpolation. From this fact it was confirmed that the neural networks trace the original values of thermodynamic properties better than the quadratic interpolation method.

  • PDF

Coal Petrological Characteristics of Korean Coal (국내탄의 석탄암석학적 특성)

  • Park, Hong Soo;Park, Suk Whan
    • Economic and Environmental Geology
    • /
    • v.22 no.2
    • /
    • pp.141-150
    • /
    • 1989
  • In order to make economic and geological evaluation of coal in Korea, proximate and ultimate analyses were carried out as well as coal petrological studies such as maceral analyses, vitrinite reflectance and sporinite fluorescence measurement. The coeffcient of correlation between each factor of both conventional utilization and coal petrological parameters were studied as in Table 5 and 6. Their conclusions were as follow: (1) for anthracite, the good parameters of coal rank are mean vitrinite reflectance, carbon content, hydrogen content and H/C atomic ratio: (2) for brown coal and sub-bituminous coal, the good parameters of coal rank are carbon content, calorific value, moisture content, hydrogen content, oxygen content and O/C atomic ratio as well as vitrinite reflectance and sporinite fluorescence. An attempt is made to infer the coalforming environment by utilization of coal petrological analyses and to make comparison of coal analyses with proximate and ultimate analyses throughout the island arc region including Japan, Philippine and Indonesia and continental region including USA, Canada and Australia. As a result, meceral composition of Paleozoic and Mesozoic anthracite are similar to that of the Paleozoic continental coals, which were formed under dry conditions or low water table, but the coalification degree suddenly increased during Daebo orogeny (middle Jurassic to lower Cretaceous). The Tertiary coal resembles those of Tertiary island arc region coal characterized by higher calorific value, volatile matter content and H/C atomic ratio and by the formation of coal under wet conditions or higher water table.

  • PDF

Design of a Smart Gas Sensor System for Room Air-Cleaner of Automobile (Thick-Film Metal Oxide Semiconductor Gas Sensor)

  • Kim, Jung-Yoon;Shin, Tae-Zi;Yang, Myung-Kook
    • Journal of Electrical Engineering and Technology
    • /
    • v.2 no.3
    • /
    • pp.408-412
    • /
    • 2007
  • It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

A Study on the Validation of Heliodon for Daylighting Performance Evaluation (자연채광성능 평가를 위한 태양고정형 Heliodon의 유용성 검증에 관한 연구)

  • Kim, Jeong-Tai;Lee, Ji-Hyun;Kim, Gon
    • Journal of the Korean Solar Energy Society
    • /
    • v.24 no.2
    • /
    • pp.51-62
    • /
    • 2004
  • Architects may evaluate building models to see how a building will shadow itself and its neighbors at various times. A heliodon, a tilt-table which is a machine that imitates the rotation and orbit of the Earth, helps architects wanting to analyze patterns of shadow patch, passive solar heating options, site solar panels, or control solar heat gain. The heliodon swivels in three directions for setting latitude, season, and time of day. Using the device, an architect first clamps a model to the tabletop, then turns the table to the coordinates of interest. Usually, the winter and summer solstices receive strong attention, for they represent extreme cases, A more recent installation at a university adds to its heliodon a set of lamps to recreate the illumination level and more accurate patterns of shadow patch. The table holds the building model at various angles to a spotlight, which mounts in the pole. The set of scale model measurement describes the validity of various electric lamps as an artificial sun to approximate the sun's parallel rays, helping designers to distinguish between illuminated areas in and around a building and those regions falling in the shadows.

Uncertainty Measurement of Incomplete Information System based on Conditional Information Entropy (조건부 정보엔트로피에 의한 불완전 정보시스템의 불확실성 측정)

  • Park, Inkyoo
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.14 no.2
    • /
    • pp.107-113
    • /
    • 2014
  • The derivation of optimal information from decision table is based on the concept of indiscernibility relation and approximation space in rough set. Because decision table is more likely to be susceptible to the superposition or inconsistency in decision table, the reduction of attributes is a important concept in knowledge representation. While complete subsets of the attribute's domain is considered in algebraic definition, incomplete subsets of the attribute's domain is considered in information-theoretic definition. Therefore there is a marked difference between algebraic and information-theoretic definition. This paper proposes a conditional entropy using rough set as information theoretical measures in order to deduct the optimal information which may contain condition attributes and decision attribute of information system and shows its effectiveness.

DNA Chip Database for the Korean Functional Genomics Project

  • Kim, Sang-Soo
    • Proceedings of the Korean Society for Bioinformatics Conference
    • /
    • 2001.10a
    • /
    • pp.11-28
    • /
    • 2001
  • The Korean functional Genomics Project focuses on stomach and liver cancers. Specimens collected by six hospital teams are used in BNA microarray experiments. Experimental conditions, spot measurement data, and the associated clinical information are stored in a relational database. Microarray database schema was developed based on EBI's ArrayExpress. A diagrammatic representation of the schema is used to help navigate over marty tables in the database. Field description, table-to-table relationship, and other database features are also stored in the database and these are used by a PERL interface program to generate web-based input forms on the fly. As such, it is rather simple to modify the database definition and implement controlled vocabularies. This PERL program is a general-purpose utility which can be used for inputting and updating data in relational databases. It supports file upload and user-supplied filters of uploaded data. Joining related tables is implemented using JavaScripts, allowing this step to be deferred to a later stage. This feature alleviates the pain of inputting data into a multi-table database and promotes collaborative data input among several teams. Pathological finding, clinical laboratory parameters, demographical information, and environmental factors are also collected and stored in a separate database. The same PERL program facilitated developing this database and its user-interface.

  • PDF

Influence of the environments on the movement precision of the guide table using externally pressurized porous air bearing (다공질 정압공기 베어링을 이용한 직진 테이블에 있어 주위환경이 움직임 정밀.정확도에 미치는 영향)

  • 한응교;허석환;노병옥
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.12 no.4
    • /
    • pp.721-729
    • /
    • 1988
  • Recently, the precision required by precision manufacturing and machinery related to electronics is within the domain of submicron that it is difficult to evaluate them by traditional measuring equipments and methods. Accordingly, precision of sub 0.1.mu.m super precise position-decision-apparatus and straight-guide air bearing have been researched and they are almost ready to be used. In utilizing straight-guide-table for super-precision-measurement which used externally pressurized porous air bearing as a way of externally pressurized air bearing, the high-precision-straight movement is the most crucial. In this study, the researcher conducted the experimental study with trial manufacture to see how the surrounding temperature and support condition influenced the selection and allocation of the machine composing element which is important to the high-precision-straight movement. The researcher finding showed that when the property of the rail part and support part of the semi-closed slider form is different, the heat generation of the working motor and surrounding temperature influence the high-precision-straight movement significantly and the researcher showed the influence of the condition of central load and eccentric load to the straight movement precision when the support stand of the straight-table was supported by numerical values.