• Title/Summary/Keyword: Approximation Order

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A Study on Clinical Feasibility and Practical Strategies for Dental Hygiene Process (ADPIE) (치위생과정(ADPIE)의 임상적용 가능성과 실천방안 모색)

  • Lee, Joo-Young;Han, Gyeong-Soon
    • Journal of dental hygiene science
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    • v.14 no.4
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    • pp.433-441
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    • 2014
  • This study was aimed to analyze factors affecting intention on clinical application by task autonomy of dental hygienists, expected effect and obstructive factor on clinical application of assessment, dental hygiene diagnosis, planning, implementation, and evaluation (ADPIE). Meanwhile, it proved mediating effects of "attitude toward ADPIE" when it came to "intention on clinical application". The data was collected from 237 dental personnel in capital region from March 28, 2014 to May 2, 2014. To analyze the suitability of a theoretical model and hypothesis testing, SPSS 21.0 and AMOS 18.0 program were used. The theoretical model was accepted as it resulted in ${\chi}^2=421.67$ while showing goodness of fit index=0.858, comparative fit index=0.915, Tucker-Lewis index=0.896, root mean square residual=0.039, and root mean square error of approximation=0.099. The result showed "task autonomy of dental hygienists (${\beta}=0.398$, p<0.05)" and "expected effect on ADPIE (${\beta}=0.363$, p<0.01)" had a positive effect on "attitude toward ADPIE". Also, "attitude toward ADPIE" had a positive effect on "intention on clinical application". In addition, "task autonomy of dental hygienists" and "expected effect on ADPIE" had an indirect influence on "intention on clinical application" via such intermediary as "attitude toward ADPIE". According to the above results, the task autonomy of dental hygienists, expected effect on ADPIE, and attitude toward ADPIE were confirmed to be significant factors when it came to the intention on its clinical application. Therefore in order to settle ADPIE in the clinical practice, improvement of task autonomy for dental hygienists as well as their expectation and attitude on ADPIE must be promoted.

A Study on the Development of Family Welfare Program for Strengthening Family Life - Special Reference to Family Life Education - (建全家庭 育成을 위한 家族福祉 프로그램 開發에 관한 硏究 - 家族生活 敎育을 中心으로 -)

  • Yoo, Young-Ju
    • Journal of Families and Better Life
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    • v.9 no.1 s.17
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    • pp.45-63
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    • 1991
  • The purpose of this study was to develop Family Welfare Program for strengthening Family Life, especially focused on the Family Life Education. In order to perform the above research purpose, this study was organized three sections. First, conceptualizing strong family second, measurement the degree of strong family third, is about the Family Life Education. I defined that the concept of strong family is functional family that is family members(husbands & wives)perform successfully internal family functions. I measured the strong family by means of family function performance scale which is composed by 54 questionnaires. Through the survey study with the family function performance scale. I recognized the necessity of Family Life Education for strengthening family function. Family Life Education(FLE)is an educational specialty which was originated in reaction to changing social conditions, industrialization, and urbanization. It deals with the perceive inadequacies of families to cope with these changes, thereby reducing social problems involved with, and improving family life. With and assumption that the studies about FLE have not been so active in Korea, the present thesis examines the FLE in Korea : i.e., the defintion, the objectives, the scope, the approximation of family life education, and the necessity of marital education in Korea based upon the published theories of FLE in the United States of America. Also, it attemps to formulate tentative plan for the promotion of a FLE program in Korea. The concept of FLE in Korea was mainfested itn the social educational law and lifespan institutional, governmental attention. It is defined as "the family life education to enhance the quality of human life, to solve family problems, to develop and individual's potentiality, and to strengthen the family interaction." Of the FLE program, the marital education is considered one of the crucial subjects because it is the core of the family life. With this premise, FLE tries to support the healthy marital relations, subsequently helping to explore the family potentiality and to strengthen family ties. Considering the seemingly dual characteristics of the contents of marital educations, and effective expressions of mutual affection. In addition, reciprocal understanding and cooperation of the married couples to overcome the differences of value, personality, hobby, and religion, the educational methods in child rearing kids, and the effective management of home economics should be included. The objects of the FLE program are unmarried, pre-married, and married persons. For the married persons, the FLE program should be arranged in accordance with their marital status classified by the family life cycle so that they amy prevent possible family problems t each stages of the family life. Also, to prevent the problems incurred in the course of carrying out family functions, the FLE program should be provided with on the basis of a family unit, there by improving the quality of the family functions.

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Prediction of Performance of Waterjet Propulsors by Surface Panel Method (패널법에 의한 물 분사 추진장치의 성능해석)

  • Moon, II-Sung;Lee, Chang-Sup;Song, In-Haeng;Kim, Ki-Sup
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.31-41
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    • 1997
  • This paper describes a potential-based panel method formulated for the prediction of the steady performance of a waterjet propulsor. The method employs normal dipoles and sources distributed on the solid surfaces such as the impeller/stator blades, hub and duct, and normal dipoles in the shed wakes trailing the impeller and stator to represent the potential flow around the waterjet propulsor. To define a closed boundary surface, the inlet and outlet open boundary surfaces are introduced where the sources and dipoles are distributed. The kinematic boundary condition on the solid boundary surface is satisfied by requiring that the normal component of the total velocity should vanish. On the inlet surface, the total inflow flux into the duct is specified, and on the outlet surface the conservation of mass principle is applied to evaluate the source strength. The solid surfaces are discretized into a set of quadrilateral panel elements and the strengths of sources and dipoles are assumed constant at each panel. Applying this approximation to the boundary conditions leads to a set of simultaneous equations. Systematic numerical tests show that the present numerical method is fast and stable. In order to validate the present method, sample computations are carried out first for the case of a conventional axial flow fan which has a similar geometry as the waterjet propulsor, and then for the case of a waterjet propulsor on which experiments are carried out at KRISO(Korea Research Institute of Ships and Ocean Engineering).

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Stereo Image-based 3D Modelling Algorithm through Efficient Extraction of Depth Feature (효율적인 깊이 특징 추출을 이용한 스테레오 영상 기반의 3차원 모델링 기법)

  • Ha, Young-Su;Lee, Heng-Suk;Han, Kyu-Phil
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.10
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    • pp.520-529
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    • 2005
  • A feature-based 3D modeling algorithm is presented in this paper. Since conventional methods use depth-based techniques, they need much time for the image matching to extract depth information. Even feature-based methods have less computation load than that of depth-based ones, the calculation of modeling error about whole pixels within a triangle is needed in feature-based algorithms. It also increase the computation time. Therefore, the proposed algorithm consists of three phases, which are an initial 3D model generation, model evaluation, and model refinement phases, in order to acquire an efficient 3D model. Intensity gradients and incremental Delaunay triangulation are used in the Initial model generation. In this phase, a morphological edge operator is adopted for a fast edge filtering, and the incremental Delaunay triangulation is modified to decrease the computation time by avoiding the calculation errors of whole pixels and selecting a vertex at the near of the centroid within the previous triangle. After the model generation, sparse vertices are matched, then the faces are evaluated with the size, approximation error, and disparity fluctuation of the face in evaluation stage. Thereafter, the faces which have a large error are selectively refined into smaller faces. Experimental results showed that the proposed algorithm could acquire an adaptive model with less modeling errors for both smooth and abrupt areas and could remarkably reduce the model acquisition time.

A Study on Depth Data Extraction for Object Based on Camera Calibration of Known Patterns (기지 패턴의 카메라 Calibration에 기반한 물체의 깊이 데이터 추출에 관한 연구)

  • 조현우;서경호;김태효
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.173-176
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    • 2001
  • In this thesis, a new measurement system is implemented for depth data extraction based on the camera calibration of the known pattern. The relation between 3D world coordinate and 2D image coordinate is analyzed. A new camera calibration algorithm is established from the analysis and then, the internal variables and external variables of the CCD camera are obtained. Suppose that the measurement plane is horizontal plane, from the 2D plane equation and coordinate transformation equation the approximation values corresponding minimum values using Newton-Rabbson method is obtained and they are stored into the look-up table for real time processing . A slit laser light is projected onto the object, and a 2D image obtained on the x-z plane in the measurement system. A 3D shape image can be obtained as the 2D (x-z)images are continuously acquired, during the object is moving to the y direction. The 3D shape images are displayed on computer monitor by use of OpenGL software. In a measuremental result, we found that the resolution of pixels have $\pm$ 1% of error in depth data. It seems that the error components are due to the vibration of mechanic and optical system. We expect that the measurement system need some of mechanic stability and precision optical system in order to improve the system.

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Compensation Characteristics of Distorted Channels in 200 Gbps WDM Systems using Mid-Span Spectral Inversion Method (200 Gbps WDM 시스템에서 Mid-Span Spectral Inversion 기법을 이용한 채널 왜곡의 보상 특성)

  • 이성렬
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.8
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    • pp.845-854
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    • 2003
  • In this paper, the characteristics of compensation for WDM channel signal distortion due to both chromatic dispersion and Ken effect in 1,000 km 200 Gbps(5${\times}$40 Gbps) WDM systems was investigated. The WDM system has a path-averaged intensity approximation(PAIA) mid-span spectral inversion(MSSI) as a compensation method. This system has a highly nonlinear dispersion shifted fiber(HNL-DSF) optical phase conjugator(OPC) in the mid-way of transmission line. In order to evaluate the degree of compensation, 1 dB eye opening penalty(EOP), bit error rate(BER) characteristics and power penalty of 10$\^$-9/ BER are used. It is confirmed that HNL-DSF is an useful nonlinear medium in OPC fur wideband WDM system with PAIA MSSI and that the optimal compensation for WDM channel distortion is achieved by the selection of pump light power of OPC, which equalize the conjugated light power into the second half fiber section with the input WDM signal light power depending on total transmission length, dispersion coefficient of fiber, OPC pump light wavelength, conversion efficiency of WDM channel in OPC.

Reduction of Chattering Error of Reed Switch Sensor for Remote Measurement of Water Flow Meter (리드 스위치 센서를 이용한 원격 검침용 상수도 계량기에서 채터링 오차 감소 방안 연구)

  • Ayurzana, Odgerel;Kim, Hie-Sik
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.4 s.316
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    • pp.42-47
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    • 2007
  • To reduce the chattering errors of reed switch sensors in the automatic remote measurement of water meter a reed switch sensor was analyzed and improved. The operation of reed switch sensors can be described as a mechanical contact switch by approximation of permanent magnet piece to generate an electrical pulse. The reed switch sensors are used mostly in measurement application to detect the rotational or translational displacement. To apply for water flow measurement devices, the reed switch sensors should keep high reliability. They are applied for the electronic digital type of water flow meters. The reed switch sensor is just mounted simply on the conventional mechanical type flow meter. A small magnet is attached on a pointer of the water meter counter rotor. Inside the reed sensor two steel leaf springs make mechanical contact and apart repeatedly as rotation of flow meter counter. The counting electrical contact pulses can be converted as the water flow amount. The MCU sends the digital flow rate data to the server using the wireless communication network. But the digital data is occurred difference or won by chattering noise. The reed switch sensor contains chattering error by it self at the force equivalent position. The vibrations such as passing vehicle near to the switch sensor installed location causes chattering. In order to reduce chattering error, most system uses just software methods, for example using filter algorithm and also statistical calibration methods. The chattering errors were reduced by changing leaf spring structure using mechanical characteristics.

Induction of the High Order Calibration Equation of Metal Oxide Semiconductor Gas Sensors (산화물 반도체식 가스센서의 입출력 고차 캘리브레이션 방정식 도출)

  • Park, Gyoutae;Kim, Kangmin;Lee, Hyeonggi;Yoon, Myeongsub
    • Journal of the Korean Institute of Gas
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    • v.24 no.2
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    • pp.44-49
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    • 2020
  • In this paper, a measuring circuit is designed through analyzing manufacture specification of the sensor based on MOS. And the best input-output polynomial are induced that really gas sensors are used in gas safety management industrial fields. Response characteristics of a MOS gas sensor is analysed by through sensor's output voltages are measured after standard gases with six kinds of concentrations are manufactured and are injected to the sensor. A lookup table is created by relations of sensor's output voltages by injecting gases with other concentrations. Because data of the formed lookup table are equal interval, a polynomial can be induced of method of approximation function. So the 5th polynomial of input-output for a sensor is defined, coefficients are calculated by using least squares method, and the 5th polynomial is completed for representing characteristics of the sensor. If the proposed polynomial is applied to gas leak detectors, an inverse transformation of polynomial and programing of array codes are recreated. In this research, polynomial is implemented with array types that intervals of values of a lookup table are one-fifth sampled and interpolated. The performance of proposed 5th calibration equation is verified that errors are reduced than a linear expression when tests are performed by measurement of concentrations against injection of standard gases.

Spatial dispersion of aggregate in concrete a computer simulation study

  • Hu, Jing;Chen, Huisu;Stroeven, Piet
    • Computers and Concrete
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    • v.3 no.5
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    • pp.301-312
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    • 2006
  • Experimental research revealed that the spatial dispersion of aggregate grains exerts pronounced influences on the mechanical and durability properties of concrete. Therefore, insight into this phenomenon is of paramount importance. Experimental approaches do not provide direct access to three-dimensional spacing information in concrete, however. Contrarily, simulation approaches are mostly deficient in generating packing systems of aggregate grains with sufficient density. This paper therefore employs a dynamic simulation system (with the acronym SPACE), allowing the generation of dense random packing of grains, representative for concrete aggregates. This paper studies by means of SPACE packing structures of aggregates with a Fuller type of size distribution, generally accepted as a suitable approximation for actual aggregate systems. Mean free spacing $\bar{\lambda}$, mean nearest neighbour distance (NND) between grain centres $\bar{\Delta}_3$, and the probability density function of ${\Delta}_3$ are used to characterize the spatial dispersion of aggregate grains in model concretes. Influences on these spacing parameters are studied of volume fraction and the size range of aggregate grains. The values of these descriptors are estimated by means of stereological tools, whereupon the calculation results are compared with measurements. The simulation results indicate that the size range of aggregate grains has a more pronounced influence on the spacing parameters than exerted by the volume fraction of aggregate. At relatively high volume density of aggregates, as met in the present cases, theoretical and experimental values are found quite similar. The mean free spacing is known to be independent of the actual dispersion characteristics (Underwood 1968); it is a structural parameter governed by material composition. Moreover, scatter of the mean free spacing among the serial sections of the model concrete in the simulation study is relatively small, demonstrating the sample size to be representative for composition homogeneity of aggregate grains. The distribution of ${\Delta}_3$ observed in this study is markedly skew, indicating a concentration of relatively small values of ${\Delta}_3$. The estimate of the size of the representative volume element (RVE) for configuration homogeneity based on NND exceeds by one order of magnitude the estimate for structure-insensitive properties. This is in accordance with predictions of Brown (1965) for composition and configuration homogeneity (corresponding to structure-insensitive and structure-sensitive properties) of conglomerates.

FORMATION AND EVOLUTION OF SELF-INTERACTING DARK MATTER HALOS

  • AHN KYUNGJIN;SHAPIRO PAUL R.
    • Journal of The Korean Astronomical Society
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    • v.36 no.3
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    • pp.89-95
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    • 2003
  • Observations of dark matter dominated dwarf and low surface brightness disk galaxies favor density profiles with a flat-density core, while cold dark matter (CDM) N-body simulations form halos with central cusps, instead. This apparent discrepancy has motivated a re-examination of the microscopic nature of the dark matter in order to explain the observed halo profiles, including the suggestion that CDM has a non-gravitational self-interaction. We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions for their dynamics, which take proper account of the collisional interaction of SIDM particles, based on a fluid approximation derived from the Boltzmann equation. The SIDM particles scatter each other elastically, which results in an effective thermal conductivity that heats the halo core and flattens its density profile. These similarity solutions are relevant to galactic and cluster halo formation in the CDM model. We assume that the local density maximum which serves as the progenitor of the halo has an initial mass profile ${\delta}M / M {\propto} M^{-{\epsilon}$, as in the familiar secondary infall model. If $\epsilon$ = 1/6, SIDM halos will evolve self-similarly, with a cold, supersonic infall which is terminated by a strong accretion shock. Different solutions arise for different values of the dimensionless collisionality parameter, $Q {\equiv}{\sigma}p_br_s$, where $\sigma$ is the SIDM particle scattering cross section per unit mass, $p_b$ is the cosmic mean density, and $r_s$ is the shock radius. For all these solutions, a flat-density, isothermal core is present which grows in size as a fixed fraction of $r_s$. We find two different regimes for these solutions: 1) for $Q < Q_{th}({\simeq} 7.35{\times} 10^{-4}$), the core density decreases and core size increases as Q increases; 2) for $Q > Q_{th}$, the core density increases and core size decreases as Q increases. Our similarity solutions are in good agreement with previous results of N-body simulation of SIDM halos, which correspond to the low-Q regime, for which SIDM halo profiles match the observed galactic rotation curves if $Q {\~} [8.4 {\times}10^{-4} - 4.9 {\times} 10^{-2}]Q_{th}$, or ${\sigma}{\~} [0.56 - 5.6] cm^2g{-1}$. These similarity solutions also show that, as $Q {\to}{\infty}$, the central density acquires a singular profile, in agreement with some earlier simulation results which approximated the effects of SIDM collisionality by considering an ordinary fluid without conductivity, i.e. the limit of mean free path ${\lambda}_{mfp}{\to} 0$. The intermediate regime where $Q {\~} [18.6 - 231]Q_{th}$ or ${\sigma}{\~} [1.2{\times}10^4 - 2.7{\times}10^4] cm^2g{-1}$, for which we find flat-density cores comparable to those of the low-Q solutions preferred to make SIDM halos match halo observations, has not previously been identified. Further study of this regime is warranted.