• Title/Summary/Keyword: Total Focusing Method

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An Improved Second-odrer Sampling Method for Digital Beam Forming in Ultrasound Imaging Systems (초음파 영상 시스템에서 디지탈 Beam Forming을 위한 개선된 2차 샘플링 방법)

  • 조완희;안영복
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.1
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    • pp.110-119
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    • 1995
  • The lateral resolution in an ultrasound imaging system is one of the most important factors for quality of the image and is determined by the beam focusing. For the better lateral resolution SDF(Sampled Delay Focusing) capable of digital focusing was proposed. The second-order sampling, one of band-width sampling methods, is suggested as being the best suitable for SDF because it allows total digital processing and is simple and economical. By proving that it introduces too much error, this article shows the second-order sampling is not appropriate for sampling of the wide-band signal generally used in ultrasound imaging systems. Also, this article suggests new sampling methods that maintain the advantages and reduce the unavoidable errors of the second-order sampling method. From computer simulation it is expected that the proposed methods reduce the errors of the second-order sampling method and can be used in real applications.

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Study on Enhancements to Ultrasonic Data Imaging Using Full Matrix Capture Technique (Full Matrix Capture 기법을 통한 초음파신호 영상화 향상 연구)

  • Lee, Tae-Hun;Yoon, Byung-Sik;Lee, Jeong-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.5
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    • pp.299-306
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    • 2015
  • A conventional phased array system can control an ultrasonic beam electronically by adjusting the excitation time delay of individual elements in a multi-element probe and produce an ultrasonic image. In Contrast, full matrix capture (FMC) is a data acquisition process that allows receiving ultrasonic signals from one single shot of the phased array transducer element through all the other elements and captures the complete dataset from every possible transmit-receive combination. This FMC data can be used to create the ultrasonic image in post processing. It is possible to produce not only images equivalent to conventional phased array image but also total focusing method (TFM) images with improved resolution and sharpness, which is virtually focused at any point in a region of interest. In this paper, the system that can perform FMC by using a conventional phased array instrument is developed, and a study was conducted on the imaging algorithms to reconstruct sector B-scan and TFM images from FMC dataset.

Reconstructing Flaw Image Using Dataset of Full Matrix Capture Technique (Full Matrix Capture 데이터를 이용한 균열 영상화)

  • Lee, Tae-Hun;Kim, Yong-Sik;Lee, Jeong-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.37 no.1
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    • pp.13-20
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    • 2017
  • A conventional phased array ultrasonic system offers the ability to steer an ultrasonic beam by applying independent time delays of individual elements in the array and produce an ultrasonic image. In contrast, full matrix capture (FMC) is a data acquisition process that collects a complete matrix of A-scans from every possible independent transmit-receive combination in a phased array transducer and makes it possible to reconstruct various images that cannot be produced by conventional phased array with the post processing as well as images equivalent to a conventional phased array image. In this paper, a basic algorithm based on the LLL mode total focusing method (TFM) that can image crack type flaws is described. And this technique was applied to reconstruct flaw images from the FMC dataset obtained from the experiments and ultrasonic simulation.

Isoelectric Focusing of the Hemolymph Proteins of the Silkworm, Bombyx mori

  • Staykova, Teodora;Popov, Petar;Grekov, Dimitar;Terzieva, Petia
    • International Journal of Industrial Entomology and Biomaterials
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    • v.8 no.1
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    • pp.117-121
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    • 2004
  • Soluble proteins of silkworm hemolymph were investigated by means of isoelectric focusing (IEF). The protein spectra during ontogenesis of races and inter-races hybrids kept in Bulgaria was studied. A total of 51 protein bands in the hemolymph from fourth larval instar to imago were ascertained. Stage specific expression was established. The specific expression of some protein bands in the individual spectra manifest phenotype of gene determinate polymorphism (HP F, HP J, HP K, HP L, HP Q - in the zone with pH gradient 3.5-6.2 and HP K, HP L, HP N, HP P, HP T - in the zone with pH gradient 9.5 - 6.2). Breed specific expression was observed. On the basis of the obtained results, it was established that the investigated breeds are heterogeneous and the isoelectric focusing method is successful when specifying the inner-race and inter-race polymorphism in silkworm.

A Computational Study of the Focusing Phenomenon of Weak Shock Wave (약한 충격파의 포커싱 현상에 관한 수치해석적 연구)

  • Kweon Yong Hun;Kim Heuy Dong
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.169-172
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    • 2002
  • When a plane shockwave reflects ken a concave wall, it is focused at a certain location, resulting in extremely high local pressure and temperature. This focusing is due to a nonlinear phenomenon of shock wave. The focusing phenomenon has been extensively applied to many diverse folds of engineering and medical treatment as well. In the current study, the focusing of shock wave over a reflector is numerically investigated using a CFD method. The Harten-Yee total variation diminishing (TVD) scheme is used to solve the unsteady, two-dimensional, compressible, Euler equations. The incident shock wave Mach number $M_{s}\;of\;1.1{\~}l.3$ is applied to the parabolic reflectors with several different depths. Detailed focusing characteristics of the shock wave are investigated in terms of peak pressure, gasdynamic and geometrical foci. The results obtained are compared with the previous experimental results. The results obtained show that the peak pressure of shock wave focusing and its location strongly depend on the magnitude of the incident shock wave and depth of parabolic reflector. It is also found that depending up on the depth of parabolic reflector, the weak shock wave focusing process can classified into three distinct patterns : the reflected shock waves do not intersect each other before and after focusing, the reflected shock waves do not intersect each other before focusing, but intersect after focusing, and the reflected shock waves intersect each other before and after focusing. The predicted Schlieren images represent the measured shock wave focusing with a good accuracy.

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A Narrative Review of Clinical researches of Acupuncture treatment for Depression using Neuroimaging method: Focusing on SCI papers

  • Lee, Dong Hyuk
    • The Journal of Korean Medicine
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    • v.42 no.4
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    • pp.208-221
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    • 2021
  • Objectives: The purpose of this article was to investigate the current status of clinical studies of acupuncture treatment for depression using neuroimaging method, focusing on SCI papers. Methods: We searched for clinical trial studies of acupuncture treatment for depression using neuroimaging method in the MEDLINE (Pubmed), OASIS, and RISS database. Once the online search was finished, studies were selected manually by the inclusion criteria. Finally, we analyzed the characteristics of selected articles and reviewed the neural substrates of acupuncture treatment in depression. Results: Total eight studies were included in this study. The most frequently utilized modality was functional MRI. The most frequently selected acupoint for depression was GV20. Several studies revealed that acupuncture treatment could improve the symptoms of depression. In this manuscript, we demonstrated that neuroimaging techniques could capture the neural substrates associated with depression and acupuncture treatment may modulate the activation of brain areas which were impaired in depression in a different way from sham acupuncture. Conclusions: Utilizing neuroimaging methods to explore neural mechanism of acupuncture treatment on depression would be helpful in clinical trials and more efforts should be needed in this fields.

An Integrative Way of Process Analysis for Better Total Quality Management: Focusing on Drug Entity (종합적 질 관리 (TQM)를 위한 프로세스 분석 방법 -의약품 실체를 중심으로-)

  • Kim, Myeng-Ki
    • Quality Improvement in Health Care
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    • v.1 no.1
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    • pp.56-65
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    • 1994
  • Total quality management has been a focus of concern in recent years since some dissatisfaction with the results from implementation of quality assurance programs in the U.S. Many managerial methodologies and innovation guidelines from academic disciplines have been applied to promote TQM programs in the health field. This paper consists of two folds of aspects: firstly to examine TQM's managerial philosophy by comparing with the newly introduced managerial concepts in Business Reengineering; and then to introduce a method for an integrative way of process analysis, Entity Life-Cycle Diagram (ELCD) modeling. The analysis method was compared with Process Map, which is a well-known method for BR applications. To show effectiveness of ELCD modeling, a case of application was introduced using 'drug' as a target entity. With having TQM issues in mind, the result was reflected in designing Entity Relation Diagrams. The results of ELCD modeling turn out to be helpful in designing database related to quality monitoring, in that many monitoring check points can be identified in a systematic way and that queries cross-sectional over organizational boundaries can be generated with a consistent view focusing on the drug use as a single process. Full evaluation of the analysis method remains to be studied until the completion of the information system under construction. But as long as TQM is based on a process-oriented view and needs supports from information system, ELCD can be one of the appropriate choice as a tool for the process analysis.

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A Quality Strategy and Self-Assessment Method for Organizational Excellence

  • Dahlgaard, Jens-J.;Park, Mi-Su
    • International Journal of Quality Innovation
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    • v.4 no.1
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    • pp.20-39
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    • 2003
  • Based on a combination of theories, experiences and cases a sustainable change strategy and self-assessment method with a focus on the human dimension in TQM are suggested and discussed. The Post Denmark TIQ (Total Involvement in Quality) case will be used to illustrate how breakthrough in people attitudes and organisational culture happened and became the foundation for a new culture focusing on change, continuous improvements and everybody's participation.

Priority Analysis for Resource Development of Waterfront in Jeju Region - Using AHP method (AHP 기법을 적용한 제주지역 친수공간 자원화방안 요인의 중요도 분석)

  • Boo, Chang-San;Kim, Suk Jong;Kim, Mincheol
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.1
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    • pp.139-151
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    • 2013
  • Recently, in the context of increased interest for marine tourism, Jeju region of South Korea has attractive waterfront space and also has potential requirements for development. The objective of this paper was to analyze the priority for resource development of waterfront in Jeju region. In order to calculate the importance of factors related to the development of waterfront in Jeju area, this study conducted exploratory factor analysis to extract the factors and established the AHP model based on the factors name focusing on a total of 198 tourists. In this study, in accordance with the procedures of AHP analysis, pairwise comparisons were conducted focusing on a total of 15 experts. Especially, difference test between groups (academics and bureaucratic) was conducted. In the 1st criterion for evaluation, 'exploring experience' factor is most important thing and 'facilities & infrastructure' factors were in the following order. In the secondary criterion, AHP analysis showed that experience facilities, environmental management, and absence of residents consciousness were the important factors. In the future time, the results of this research can be utilized as basic data in the aspects of tourism development in Jeju waterfront region.

Secondary Analysis: Focusing on Qualitative Research (이차분석 : 질적연구를 중심으로)

  • 이명선
    • Journal of Korean Academy of Nursing
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    • v.34 no.1
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    • pp.35-44
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    • 2004
  • Purpose: This article explored issues arising from secondary analysis of qualitative data and analyzed the results of qualitative secondary analysis studies published in English, focusing on the methodological aspects. Method: A total of 29 studies were identified as qualitative secondary analysis studies, retrieving from the CINAHL database from 1982 to 3rd week of April 2003. These studies were analyzed by publication year, research method, and type of approach to secondary analysis. Result: The year that the qualitative secondary analysis study first published was 1992 and the number of the studies using secondary analysis has increased after the middle of 1990s. Grounded theory was the one the most frequently used(n=11, 37.9%) and phenomenological study the second most(n=6, 20.7%). In terms of types of approach, fifteen studies(51.7%) focused on the specific concepts that were not explored in the primary studies. Nine(31.0%) focused on the specific types of participants. Six were aimed to integrate contexts or perspectives to generate more general and abstract analysis of qualitative data. Conclusion: The results of this article will stimulate methodological discussion of qualitative secondary analysis and activate qualitative studies using secondary analysis.