• Title/Summary/Keyword: Frequency focusing

Search Result 940, Processing Time 0.026 seconds

Development of the Advanced NDI Technique Using an Alternating Current : the Evaluation of surface crack and blind surface crack and the detection of defects in a field component (교류전류를 이용한 새로운 비파괴탐상법의 개발;표면결함과 이면결함의 평가 및 실기 부재의 결함 검출)

  • Kim. H.;Lim, J.K.
    • Journal of Welding and Joining
    • /
    • v.13 no.2
    • /
    • pp.42-52
    • /
    • 1995
  • In the evaluation of aging degradation on the structural materials based on the fracture mechanics, the detection and size prediction of defect are very important. Aiming at nondestructive detection and size prediction ol defect with high accuracy and resolution, therefore, an lnduced Current Focusing Potential Drop(ICFPD) technique has been developed. The principle of this technique is to induce a focusing current at an exploratory region by an induction wire flowing an alternating current(AC) that is a constant ampere and frequency. Defects are assessed with the potential drops that are measured the induced current on the surface of metallic material by the potential pick-up pins. In this study, the lCFPD technique was applied for evaluating the location and size of the surface crack and blind crack made in plate specimens, and also for detecting the defects existing in valve, a field component, that were developed by SCC etc. during the service. The results of this present study show that surface crack and blind crack are able to defect with potential drop. these cracks are distinguished with the distribution of potential drop, and the crack depths can be estimated with each normalized potential drop that are parameters estimating the depth of each type crack. In the field component, the defects estimated by experiment result correspond with those in the cutting face of the measuring point within a higher sensitivity.

  • PDF

A Study on Convergence Family Function and parameter validation fusion of youth protection factor (융합적 가족 기능과 청소년 보호요인의 매개검증에 관한 연구)

  • Jang, Chun-Ok
    • Journal of the Korea Convergence Society
    • /
    • v.6 no.4
    • /
    • pp.121-126
    • /
    • 2015
  • Korea Youth Panel (2008) has 2 panels of the 5th year of Knowledge data to perform statistical analysis and regression analysis, the risk factors in the risk conditions of the family of functional deficits, protective factors, the relationship between the mediating effect of psychological adaptation and protective factors verification mechanisms and the psychological adaptation level it is an objective to analyze the protective factors that protect the high youth. To investigate the differences by frequency analysis and personal characteristics of the analyte's was performed t test using PASW (Predictive Analytics Software) 18.0. And to verify the effect of the parameters is performed rank regression analysis for verification of the effects of protection factors for adaptation. Rather than focusing on youth risk factors in social welfare practice field, focusing on processes and protective factors to reduce the risk factors, it is possible to convert the viewpoint overlooking the youth exposed to risk factors. Also, for young people experiencing difficulties that features loss of the family, it is determined that the prepared foundation which can be provided in the direction of social welfare practical intervention.

Genetic Polymorphism of Plasma Vitamin D-Binding Protein (Gc) in Some Asian Sheep

  • Tsunoda, K.;Doge, K.;Hasnath, M.A.;Rajbhandary, H.B.;Xu, W.;Zhanchiv, T.;Chau, B.L.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.11 no.3
    • /
    • pp.318-322
    • /
    • 1998
  • Using polyacrylamide-gel isoelectric focusing followed by immunoblotting, genetic polymorphism of plasma vitamin D-binding protein (Gc) was examined in Asian sheep. The Gc polymorphism was revealed in the Khalkhas sheep of Mongolia, consisting of F, S and W variants, and the Yunnan native sheep of China, consisting of F and S variants. In particular, W was a new variant. The V variant detected in European sheep up to now was not observed in these sheep. The Bhyanglung, Baruwal, Kagi and Lampuchhre sheep of Nepal and local sheep of Bangladesh and Vietnam were monomorphic for the S variant. Family data and population genetic data supported the hypothesis that these variants were controlled by codominant alleles. In these Asian sheep, distribution of the $Gc^s$ allele was predominant (0.9571-1) and was seen as well in European sheep (Suffolk, Corriedale, Cheviot and Finnish Landrace) raised in Japan. $Gc^w$ allele was detected only in the Khalkhas sheep with the low frequency of 0.0025. The $Gc^v$ allele was detected in the Suffolk and Corriedale sheep (0.0080 and 0.0682), but not in any of the Asian sheep studied.

Content Analysis of Presidents' Addresses of English Literary Societies in Korea: Focusing on Analysis of a Language Network (영어영문학 관련 학회장 인사말 내용분석 - 언어네트워크분석을 중심으로)

  • Choi, Kyoungho;Mun, Gil Seong
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.3
    • /
    • pp.495-501
    • /
    • 2013
  • The words a speaker uses can be regarded as the core, the main issue and a symbolic icon of what he says. Applying this to presidents' addresses of each English literary society in Korea shows that frequency in use and the linkage of words they use in their addresses are value and ideas executive officers pursue. The purpose of this study is to analyze the contents of presidents' addresses introduced in home page of each English literary society in Korea and investigate features and constitution of them each, focusing on analysis of a language network. The results of this study show the features of resemblances and differences of commonly-used words. In addition, these results appear to suggest that they can be also applied to a comparative study between the English literary societies in Korea.

Subsurface Imaging Technology For Damage Detection of Concrete Structures Using Microwave Antenna Array (안테나배열을 이용한 콘크리트부재 내부의 비파괴시험과 영상화방법 개발)

  • Kim, Yoo-Jin;Choi, Ko-Il;Jang, Il-Young
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.5 no.2 s.17
    • /
    • pp.1-8
    • /
    • 2005
  • Microwave tomographic imaging technology using a bi-focusing operator has been developed in order to detect the internal voids/objects inside concrete structures. The imaging system consists of several cylindrical or planar array antennas for transmitting and receiving signals, and a numerical focusing operator is applied to the external signals both in transmitting and in receiving fields. In this study, the authors developed 3-dimensional (3D) electromagnetic (EM) imaging technology to detect such damage and to identify exact location of steel rebars or dowel. The authors have developed sub-surface two-dimensional (2D) imaging technique using tomographic antenna array in previous works. In this study, extending the earlier analytical and experimental works on 2D image reconstruction, a 3D microwave imaging system using tomographic antenna way was developed, and multi-frequency technique was applied to improve quality of the reconstructed image and to reduce background noises. Numerical simulation demonstrated that a sub-surface image can be successfully reconstructed by using the proposed tomographic imaging technology. For the experimental verification, a prototype antenna array was fabricated and tested on a concrete specimen.

Subject Region-Based Auto-Focusing Algorithm Using Noise Robust Focus Measure (잡음에 강인한 초점 값을 이용한 피사체 중심의 자동초점 알고리듬)

  • Jeon, Jae-Hwan;Yoon, In-Hye;Lee, Jin-Hee;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.48 no.2
    • /
    • pp.80-87
    • /
    • 2011
  • In this paper we present subject region-based auto-focusing algorithm using noise robust focus measure. The proposed algorithm automatically estimates the main subject using entropy and solves the traditional problems with a subject position or high frequency component of background image. We also propose a new focus measure by analyzing the discrete cosine transform coefficients. Experimental results show that the proposed method is more robust to Gaussian and impulse noises than the traditional methods. The proposed algorithm can be applied to Pan-tilt-zoom (PTZ) cameras in the intelligent video surveillance system.

Spin in Randomised Clinical Trial Reports of Interventions for Obesity (비만 중재 관련 무작위배정 비교임상연구 보고의 spin 연구)

  • Lee, Sle;Won, Jiyoon;Kim, Seoyeon;Park, Su Jeong;Lee, Hyangsook
    • Korean Journal of Acupuncture
    • /
    • v.34 no.4
    • /
    • pp.251-264
    • /
    • 2017
  • Objectives : To identify the prevalence and types of spin in randomised controlled trials(RCTs) of obesity with statistically non-significant results for primary outcomes to provide adequate reporting directions. Methods : Spin is specific reporting strategy that could lead the readers to misinterpret the results of RCTs. RCTs on obesity with statistically non-significant primary outcomes published from July 2015 to June 2016 were retrieved from PubMed. All included RCTs were classified into 3 intervention categories. The identification and classification of spin in the included articles was performed by two independent researchers. Results : Among 46 RCTs with statistically non-significant primary outcomes, 32 studies were assessed as having at least one spin in title, abstract or main text. Of these, 9 articles were on complementary and alternative medicine, 7 on western medicine and 16 on dietary supplement and exercise. The frequency of spin among the types of interventions was similar. The most common type of spin was 'focusing on statistical significance within-group comparison' in results section of abstract and main text, and 'focusing only on treatment effectiveness with no consideration of statistical significance' in conclusion section of abstract and main text. Studies where random sequence generation was appropriately done was less likely to have spin. Conclusions : As a majority of obesity RCTs have spin, researchers should pay more attention to adequately interpreting and reporting statistically non-significant results.

Spatial Manipulation of Sound Using Multiple Sources (다수의 음원을 사용한 공간의 소리 제어 방법론)

  • Choi, Joung-Woo;Kim, Yang-Hann;Park, Young-Jin
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.15 no.12 s.105
    • /
    • pp.1378-1388
    • /
    • 2005
  • Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

Trend of Creativity-related Spatial Design Education Focusing on Design Process (공간디자인의 창의성 연계 교육 연구동향 -디자인 프로세스를 중심으로-)

  • An, Somi
    • Journal of Digital Convergence
    • /
    • v.14 no.8
    • /
    • pp.441-451
    • /
    • 2016
  • The purpose of this study is to analyze the trend of spatial design education focusing on creativity based on design process. In this research, the theoretical frame of design process focused on creativity was organized and the trend of creativity education study in the spatial design and other design sectors was compared and analyzed. As a result of the research, the creativity education study of spatial design analyzed such a result showed the relatively low frequency, many of studies related to formative expression of idea. On the contrary, the creativity education of other design sectors is related to overall process the most, the major contents were represented as a creativity enhancement eduction through the conversion with other sectors, the utilization of study method and theology and the utilization of IT technology. The result of this study suggests that more various attempts are required for the spatial design education and that the attempts should orient the conversion between science and art, humanity and science and the integrated access of digital and analogue.

The study on the effect of live commerce users' motivation on engagement and attitude: Focusing on the Untact consumption culture (라이브커머스 이용자의 동기가 인게이지먼트 및 태도에 미치는 영향 연구: 비대면 소비문화를 중심으로)

  • Yan, Wen-Yan;Qu, Yu-Bing;Yoon, Yeong-Hye
    • Journal of Digital Convergence
    • /
    • v.20 no.5
    • /
    • pp.221-226
    • /
    • 2022
  • The purpose of this study is to explore the differentiated motivations of users of live commerce by focusing on the entry into untact consumption culture. In addition, we intend to verify the mediating effect of engagement in the relationship between the motivation and attitude of live commerce use. As for the research method, an online survey was conducted targeting live commerce users, and 245 valid samples were used for analysis. For data analysis, frequency analysis, exploratory factor analysis, reliability analysis, multiple regression analysis, and mediation regression analysis were performed. As a result of the analysis, the motivation for using live commerce was derived from four factors: Enjoyment of interaction, Substitutability of personal examination, Need for community, Trend setting. And Engagement was found to have a significant effect on attitude. Finally, engagement was found to have a partial mediating effect in the relationship between the motivation and attitude of live commerce use. The research results will provide implications for understanding non-face-to-face consumption culture and establishing effective strategies for the live commerce industry in the future.