• 제목/요약/키워드: susceptibility effect

검색결과 665건 처리시간 0.027초

Effect of the Mg Content on the Solidification Cracking Susceptibility of the Al-Mg Alloy Laser Welds

  • Yoon, J.W.
    • International Journal of Korean Welding Society
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    • 제1권1호
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    • pp.63-70
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    • 2001
  • The solidification cracking susceptibilities of Al-Mg alloy laser welds were assessed using self-restraint tapered specimen crack test. The dependence of cracking susceptibility of Al-Mg alloy laser welds on Mg contents was observed to be similar to that of arc welds in the same materials. The cracking susceptibility of Al-Mg alloy laser welds increased as Mg content increased up to 1.6-1.9 wt.% and then it decreased as Mg content increased further. The peak cracking susceptibility occurred at around 1.6 to 1.9 wt.% Mg for both autogenous and wire feed welds. It was also observed that the cracking susceptibility decreased as the grain size of Al-Mg alloy laser welds decreased, when Mg content was in the range higher than 1.9 wt.%.

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핵자기 공명 단층 촬영에서의 자화율 강조 영상법 (Susceptibility Contrast Enhancement Imaging in MRI)

  • 노용만;문치웅;임태환;조장희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1992년도 춘계학술대회
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    • pp.85-91
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    • 1992
  • In MRI, an image contrast can be developed as a result of the susceptibility effect if an object has paramagnetic substances. This is mainly due to the non-uniform phase distribution or linear gradient developed by the magnetic susceptibility within a voxel, which in turn reduces the signal intensity; e.g., spin phases are dephased and thereby cancel each other resulting in a reduced signal. In this paper, a new concept for manipulating the susceptibility effect through the use of tailored RF pulses is proposed. As potential applications of the method, two different types of tailored RF pulses are introduced: one for susceptibility artifact correction and the other for contrast enhancement. The latter, for example, can be applied to angiography utilizing the paramagnetic property of deoxygenated blood. Both a theoretical study of the method and experimental results are reported.

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Gender Difference in Mediating Effects of Self-Efficacy for the Prevention of Sexually Transmitted Diseases (STD) among College Students' STD Knowledge, Susceptibility, and Sexual Autonomy

  • Park, Mijeong
    • 성인간호학회지
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    • 제28권4호
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    • pp.482-490
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    • 2016
  • Purpose: The purpose of the study was to examine the impact of self-efficacy in the prevention of sexually transmitted diseases (STD), knowledge of and susceptibility to STD, and the role of gender in sexual autonomy. Methods: Data were collected from 267 college students using self-report questionnaires during the period from the first to the twentieth of June 2015. Data were analyzed using $x^2$ test, Fisher's exact test, t-test, Pearson correlation coefficients, simple and multiple regression techniques with the PASW/WIN 20.0 program. Mediation analysis was performed according to the Baron and Kenny method and Sobel test. Results: In male students, self-efficacy for STD prevention showed a full mediating effect in the relationship between STD susceptibility and sexual autonomy (${\beta}$=-.08, p=.370). But in female students, it had a partial mediating effect (${\beta}$=-.25, p=.001). And self-efficacy for STD prevention showed partial mediating effects in the relationship between knowledge of STD and sexual autonomy in the both male (${\beta}$=.25, p=.005) and female students (${\beta}$=.33, p<.001). Conclusion: To enhance college students' sexual autonomy, it may be useful to build effective strategies enhancing students' knowledge about and susceptibility to STD and to develop a self-efficacy promotion program for college students.

금속 생체재료를 위한 Sn 함량에 따른 Zr-7Cu 합금설계 (Zr-7Cu Alloy Design According to Sn Content for Bio-Metallic Materials)

  • 김민석;김정석
    • 한국재료학회지
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    • 제31권12호
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    • pp.690-696
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    • 2021
  • The purpose of this study is to develop a zirconium-based alloy with low modulus and magnetic susceptibility to prevent the stress-shielding effect and the generation of artifacts. Zr-7Cu-xSn (x = 1, 5, 10, 15 mass%) alloys are prepared by an arc melting process. Microstructure characterization is performed by microscopy and X-ray diffraction. Mechanical properties are evaluated using micro Vickers hardness and compression test. The magnetic susceptibility is evaluated using a SQUID-VSM. The average magnetic susceptibility value of the Zr-7Cu-xSn alloy is 1.176 × 10-8 cm3g-1. Corrosion tests of zirconium-based alloys are conducted through polarization test. The average Icorr value of the Zr-7Cu-xSn alloy is 0.1912 ㎂/cm2. The elastic modulus value of 14 ~ 18 GPa of the zirconium-based alloy is very similar to the elastic modulus value of 15 ~ 30 GPa of the human bone. Consequently, the Sn added zirconium alloy, Zr-7Cu-xSn, is very interesting and attractive as a biomaterial that reduces the stress-shielding effect caused by differences of elastic modulus between human bone and metallic implants. In addition, this material has the potential to be used in metallic dental implants to effectively eliminate artifacts in MRI images due to low magnetic susceptibility.

Consumers' Susceptibility to Global Culture and Their Attitude toward the Global SPA Brand

  • Hwang, Ji-Hyun;Hwang, Choon-Sup
    • 유통과학연구
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    • 제11권11호
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    • pp.49-55
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    • 2013
  • Purpose - This study examined the effects of susceptibility to global consumer culture (SGCC) on the brand attitude of consumers of the global SPA brand in South Korea. Research Design, Data, and Methodology -Questionnaires were used, and the sample that was extracted by the convenience sampling method comprised 703 males and females, aged 20-36. The data were analyzed with SPSS 16.0 and Amos 5.0 for frequency analysis, exploratory factor analysis, confirmatory factor analysis, reliability analysis, correlation analysis, and structural equation modeling analysis. Results - First, conformity to consumption trends was found to have a significant effect on all four variables of SPA brand attitude (brand favorability, uniqueness, ethicality, and economic utility). Second, quality perception was found to have a significant effect on brand favorability, uniqueness, ethicality, and economic utility. Third, social prestige was found to have a positive effect on uniqueness. Conclusions - The results show that consumers' susceptibility to global culture is a significant factor in their attitude to the global SPA brand. Therefore, it would be more effective if the global SPA brand develops recognition among consumers that its products play a role in sharing new trends and global lifestyles.

뇌기능 영상을 위한 TRFGE, CGE 기법에서 이미징 모드와 기울임 각의 변화에 따른 자화율 효과의 해석 (Analysis of Susceptibility Effects by Variation of Imaging Modes and Tilting Angles in TRFGE and CGE Sequences for fMRI)

  • 정순철;노용만;조장희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.571-574
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    • 1997
  • fMRI, functional MRI introduced recently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. Common to all the gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^*$ effect or conventionally known as blood oxygenation level dependent (BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due to the tilting angle of the imaging planes. Study has been made or both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity against susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

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Effect of Spatial Resolutions on the Accuracy to Landslide Susceptibility Mapping

  • Choi, J. W.;Lee, S.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.138-140
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    • 2003
  • The aim of this study is to evaluate the effect of spatial resolutions on the accuracy to landslide susceptibility mapping. For this, landslide locations were identified in the Boun, Korea from interpretation of aerial photographs and field surveys. The topographic, soil, forest, geologic, linearment and land use data were collected, processed and constructed into a spatial database using GIS and remote sensing data. The 15 factors that influence landslide occurrence were extracted and calculated from the spatial database with 5m, 10m, 30m, 100m and 200m spatial resolutions. Landslide hazardous area were analysed and mapped using the landslide-occurrence factors by probability model, likelihood ratio, for the five cases spatial resolutions. The results of the analysis were verified using the landslide location data. In the cases of spatial resolution 5m, 10m and 30m, the verification results was similar, but in the cases of 100m and 200m the results worse than the others. Because the scale of input data was 1:5,000 ? 1:50,000, so the cases of 5m, 10m and 30m have similar accuracy but the cases of 100m and 200m have the lower accuracy. From this, there is an effect of spatial resolutions on accuracy and landslide susceptibility mapping the result is dependent on input map.

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조직의 정보보안 공정성이 개인의 정보보안 관련 가치 일치 및 제언 행동에 미치는 영향: 대인 간 영향 민감성의 적용 (The Impact of Information Security(IS) Organizational Justice on Employee IS Value Congruence and IS Voice Behavior: Exploring the Role of Susceptibility to Interpersonal Influence)

  • 황인호
    • 한국정보시스템학회지:정보시스템연구
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    • 제32권4호
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    • pp.1-28
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    • 2023
  • Purpose Recently, organizations have been allocating significant financial resources toward the implementation of new technologies and stringent information security (IS) policies in order to enhance IS. However, the potential for IS threats from internal sources within organizations remains high. This study proposes a mechanism whereby the organization's IS environment (organizational justice) enhances employees' perception of IS value congruence and encourages their voice behavior. Furthermore, this study validates that an individual's susceptibility to interpersonal influence can reinforce the relationship between the aforementioned factors and voice behavior. Design/methodology/approach We utilized AMOS 22.0 and Process 3.1 to validate the research model and hypotheses. The data was gathered from 435 employees employed in South Korean firms that implemented IS policies in their work. Structural equation modeling was employed to examine the relationship between organizational justice, value congruence, and voice behavior, and the interaction effect was confirmed by incorporating model 1 of Process 3.1 for the hypothesis pertaining to susceptibility to interpersonal influence. Findings The findings of this study indicate that organizational justice has a positive impact on voice behavior, which is further enhanced by value congruence. Furthermore, the influence of organizational justice and value congruence on voice behavior is moderated by susceptibility to information influence, while susceptibility to normative influence only moderates the effect of organizational justice. These results provide valuable insights for organizations in developing customized information systems strategies that effectively promote employees' voice behaviors.

뇌기능 영상을 위한 TRFGE와 CGE 기법에서 자화율 효과의 정량적 해석 (Quantitative Analysis of Susceptibility Effects in TRFGE and CGE Sequences for Functional MRI)

  • 정순철;노용만;조장희
    • Investigative Magnetic Resonance Imaging
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    • 제1권1호
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    • pp.66-74
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    • 1997
  • 혈액의 산소화와 불 산소화에 따른 국부적인 자화율 효과의 변화에 의한 자장의 불 균일성에 민감한 경사 자장 에코 기법은 현재의 뇌기능 MR 영상의 기본이 되고 있다. 일반적으로 이러한 경사 자장 에코기법은 $T2^{*}$ 혹은 BOLD효과에 의한 자장의 불 균일성의 증가가 신호의 감소로 나타난다. BOLD 효과는 주자장에 대한 핏줄의 방향이나 영상 형식, 즉, 횡단면, 관상면, 또는 시상면에 따라 달라진다. 그래서 영상 형식과 영상면에 대한 기울임 각에 따른 신호의 변화와 BOLD 효과의 변화에 대한 정량적인 연구를 하였다. 연구는 자화율 효과에 대해 다른 민감도를 가지는 TRFGE 와 CGE 기법으로 이루어졌다. 컴퓨터 모의 실험과 실험 결과를 본 논문에 나타내었다.

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핵자기 뇌기능 영상에서 SSFPI 기법을 이용한 자화율효과의 관찰 (Observation of Susceptibility Change in fMRI Using SSFP Interferometry (SSFPI) Technique)

  • 정준영;정순철;노용만;조장희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 추계학술대회
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    • pp.173-176
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    • 1995
  • We have developed a fast steady state free precession interferometry (SSFPI) technique which is useful for the fMRI (functional Magnetic Resonance Imaging). As is known, SSFP sequence with a suitable adjustment of gradient (readout) allows us to measure precession angle $\theta$ which is in turn related to the field inhomogeneity [1-3]. When the method is applied to the susceptibility effect based functional magnetic resonance imaging (fMRI), it was found that the direct susceptibility effect measurement was possible without perturbations such as the backgrounds and inflow effect. In this paper, simulation results and experimental results obtained with 2.0 Tesla MRI system are also presented.

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