• Title/Summary/Keyword: Sample orientation

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High Pressure Phase Transition Study of ${\alpha}$-cristobalite $GaPO_4$ (${\alpha}$-크리스토발라이트 구조의 $GaPO_4$에 대한 고압 상변이 연구)

  • Hwang, Gil-Chan;Kim, Young-Ho
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.3
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    • pp.267-272
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    • 2010
  • High pressure x-ray diffraction patterns of ${\alpha}$-cristobalite gallium phosphate ($GaPO_4$) were acquired up to 8.9 GPa at room temperature using Mao-Bell type diamond anvil cell with high flux synchrotron radiation. Starting orthorhombic phase (phase-I) shows the splitting of peak which is possibly resulted from the pressure induced orientation disorder of the framework structure of tetrahedra. This is designated as phase-I'. This phase transforms to the orthorhombic high pressure phase-III between 2 and 3 GPa. Present phase transition sequence is not in accord with the recent high pressure X-ray diffraction results performed on the same starting sample (Ming et al., 2007). X-ray pattern of the unloaded sample to ambient pressure shows that the structure retains that of the high pressure phase prior to decompression.

Nd1+XBa2-XCu3O7-δ Bulk Superconductor by Zone-melt Process

  • Soh, Dea-Wha;Guo, Fan-Zhan
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.3
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    • pp.21-24
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    • 2002
  • Two kinds of $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$, the sintering samples and zone melting samples, were heat-treated under pure Ar at 950$^{circ}C$. The substitution of Nd ion for Ba ion in the $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$ before and after the heat treatment was investigated by XRD. In order to confirm the effects of the heat treatment, the Tc and Jc of samples with/without the heat treatment under Ar were comparatively studied. $Nd_{1+X}Ba_{2-X}Cu_3O_{7-{\delta}}$ samples were oxygenated under pure oxygen at $300^{circ}C$. From the XRD pattern it was found that the sample with x<0.4 was transferred from tetragonal phase to orthorhombic phase after the oxygenation, while the sample with x>0.4 did not show the phase transition even after a long time oxygenation. Therefore, the low oxygen partial pressure (Ar+1 % O$_2$) was used for the ambient atmosphere of the zone-melting samples, which could reduce the melting temperature and depress the substitution of Nd for Ba. After the improvement in the zone-melting process, the Jc value was increased to 2 x $10^4$A/$cm^2$ (0 T, 78 K). The particle orientation and the structure of zone-melted NdBaCuO were studied by the XRD and SEM analysis.

Study of cracks in compressed concrete specimens with a notch and two neighboring holes

  • Vahab, Sarfarazi;Kaveh, Asgari;Shirin, Jahanmiri;Mohammad Fatehi, Marji;Alireza Mohammadi, Khachakini
    • Advances in concrete construction
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    • v.14 no.5
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    • pp.317-330
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    • 2022
  • This paper investigated computationally and experimentally the interaction here between a notch as well as a micropore under uniaxial compression. Brazilian tensile strength, uniaxial tensile strength, as well as biaxial tensile strength are used to calibrate PFC2d at first. Then, uniaxial compression test was conducted which they included internal notch and micro pore. Experimental and numerical building of 9 models including notch and micro pore were conducted. Model dimensions of models are 10 cm × 10 cm × 5 cm. Joint length was 2 cm. Joints angles were 30°, 45° and 60°. The position of micro pore for all joint angles was 2cm upper than top of the joint, 2 cm upper than middle of joint and 2 cm upper than the joint lower tip, discreetly. The numerical model's dimensions were 5.4 cm × 10.8 cm. The fractures were 2 cm in length and had angularities of 30, 45, and 60 degrees. The pore had a diameter of 1 cm and was located at the top of the notch, 2 cm above the top, 2 cm above the middle, and 2 cm above the bottom tip of the joint. The uniaxial compression strength of the model material was 10 MPa. The local damping ratio was 0.7. At 0.016 mm per second, it loaded. The results show that failure pattern affects uniaxial compressive strength whereas notch orientation and pore condition impact failure pattern. From the notch tips, a two-wing fracture spreads almost parallel to the usual load until it unites with the sample edge. Additionally, two wing fractures start at the hole. Both of these cracks join the sample edge and one of them joins the notch. The number of wing cracks increased as the joint angle rose. There aren't many AE effects in the early phases of loading, but they quickly build up until the applied stress reaches its maximum. Each stress decrease was also followed by several AE effects. By raising the joint angularities from 30° to 60°, uniaxial strength was reduced. The failure strengths in both the numerical simulation and the actual test are quite similar.

Preparing for low-surface-brightness science with the Rubin Observatory: characterisation of LSB tidal features from mock images

  • Martin, Garreth W.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.40.3-41
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    • 2021
  • Minor mergers leave behind long lived, but extremely faint and extended tidal features including tails, streams, loops and plumes. These act as a fossil record for the host galaxy's past interactions, allowing us to infer recent accretion histories and place constraints on the properties and nature of a galaxy's dark matter halo. However, shallow imaging or small homogeneous samples of past surveys have resulted in weak observational constraints on the role of galaxy mergers and interactions in galaxy assembly. The Rubin Observatory, which is optimised to deliver fast, wide field-of-view imaging, will enable deep and unbiased observations over the 18,000 square degrees of the Legacy Survey of Space and Time (LSST), resulting in samples of potentially of millions of objects undergoing tidal interactions. Using realistic mock images produced with state-of-the-art cosmological simulations we perform a comprehensive theoretical investigation of the extended diffuse light around galaxies and galaxy groups down to low stellar mass densities. We consider the nature, frequency and visibility of tidal features and debris across a range of environments and stellar masses as well as their reliability as an indicator of galaxy accretion histories. We consider how observational biases such as projection effects, the point-spread-function and survey depth may effect the proper characterisation and measurement of tidal features, finding that LSST will be capable of recovering much of the flux found in the outskirts of L* galaxies at redshifts beyond local volume. In our simulated sample, tidal features are ubiquitous In L* galaxies and remain common even at significantly lower masses (M*>10^10 Msun). The fraction of stellar mass found in tidal features increases towards higher masses, rising to 5-10% for the most massive objects in our sample (M*~10^11.5 Msun). Such objects frequently exhibit many distinct tidal features often with complex morphologies, becoming increasingly numerous with increased depth. The interpretation and characterisation of such features can vary significantly with orientation and imaging depth. Our findings demonstrate the importance of accounting for the biases that arise from projection effects and surface-brightness limits and suggest that, even after the LSST is complete, much of the discovery space in low surface-brightness Universe will remain to be explored.

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Preparation and Structure Properties of LaBa2Cu2O9, LaBa22CaCu3O12 and LaBa2Ca2Cu5O15 Perovskites

  • Kareem Ali Jasim;Hind Abdulmajeed Mahdi;Rafah Ismael Noori;Marwa Ayad Abdulmajeed
    • Korean Journal of Materials Research
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    • v.33 no.9
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    • pp.367-371
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    • 2023
  • In this study we examine variations in the structure of perovskite compounds of LaBa2Cu2O9, LaBa22CaCu3O12 and LaBa2Ca2Cu5O15 synthesized using the solid state reaction method. The samples' compositions were assessed using X-ray fluorescence (XRF) analysis. The La: Ba: Ca: Cu ratios for samples LaBa2Cu2O9, LaBa22CaCu3O12 and LaBa2Ca2Cu5O15 were found by XRF analysis to be around 1:2:0:2, 1:2:1:3, and 1:2:2:5, respectively. The samples' well-known structures were then analyzed using X-ray diffraction. The three samples largely consist of phases 1202, 1213, and 1225, with a trace quantity of an unknown secondary phase, based on the intensities and locations of the diffraction peaks. According to the measured parameters a, b, and c, every sample has a tetragonal symmetry structure. Each sample's mass density was observed to alter as the lead oxide content rose. Scanning electron microscope (SEM) images of the three phases revealed that different Ca-O and Cu-O layers can cause different grain sizes, characterized by elongated thin grains, without a preferred orientation.

Self-Regulatory Mode Effects on Emotion and Customer's Response in Failed Services - Focusing on the moderate effect of attribution processing - (고객의 자기조절성향이 서비스 실패에 따른 부정적 감정과 고객반응에 미치는 영향 - 귀인과정에 따른 조정적 역할을 중심으로 -)

  • Sung, Hyung-Suk;Han, Sang-Lin
    • Asia Marketing Journal
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    • v.12 no.2
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    • pp.83-110
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    • 2010
  • Dissatisfied customers may express their dissatisfaction behaviorally. These behavioral responses may impact the firms' profitability. How do we model the impact of self regulatory orientation on emotions and subsequent customer behaviors? Obviously, the positive and negative emotions experienced in these situations will influence the overall degree of satisfaction or dissatisfaction with the service(Zeelenberg and Pieters 1999). Most likely, these specific emotions will also partly determine the subsequent behavior in relation to the service and service provider, such as the likelihood of complaining, the degree to which customers will switch or repurchase, and the extent of word of mouth communication they will engage in(Zeelenberg and Pieters 2004). This study investigates the antecedents, consequences of negative consumption emotion and the moderate effect of attribution processing in an integrated model(self regulatory mode → specific emotions → behavioral responses). We focused on the fact that regret and disappointment have effects on consumer behavior. Especially, There are essentially two approaches in this research: the valence based approach and the specific emotions approach. The authors indicate theoretically and show empirically that it matters to distinguish these approaches in services research. and The present studies examined the influence of two regulatory mode concerns(Locomotion orientation and Assessment orientation) with making comparisons on experiencing post decisional regret and disappointment(Pierro, Kruglanski, and Higgins 2006; Pierro et al. 2008). When contemplating a decision with a negative outcome, it was predicted that high (vs low) locomotion would induce more disappointment than regret, whereas high (vs low) assessment would induce more regret than disappointment. The validity of the measurement scales was also confirmed by evaluations provided by the participating respondents and an independent advisory panel; samples provided recommendations throughout the primary, exploratory phases of the study. The resulting goodness of fit statistics were RMR or RMSEA of 0.05, GFI and AGFI greater than 0.9, and a chi-square with a 175.11. The indicators of the each constructs were very good measures of variables and had high convergent validity as evidenced by the reliability with a more than 0.9. Some items were deleted leaving those that reflected the cognitive dimension of importance rather than the dimension. The indicators were very good measures and had convergent validity as evidenced by the reliability of 0.9. These results for all constructs indicate the measurement fits the sample data well and is adequate for use. The scale for each factor was set by fixing the factor loading to one of its indicator variables and then applying the maximum likelihood estimation method. The results of the analysis showed that directions of the effects in the model are ultimately supported by the theory underpinning the causal linkages of the model. This research proposed 6 hypotheses on 6 latent variables and tested through structural equation modeling. 6 alternative measurements were compared through statistical significance test of the paths of research model and the overall fitting level of structural equation model and the result was successful. Also, Locomotion orientation more positively influences disappointment when internal attribution is high than low and Assessment orientation more positively influences regret when external attribution is high than low. In sum, The results of our studies suggest that assessment and locomotion concerns, both as chronic individual predispositions and as situationally induced states, influence the amount of people's experienced regret and disappointment. These findings contribute to our understanding of regulatory mode, regret, and disappointment. In previous studies of regulatory mode, relatively little attention has been paid to the post actional evaluative phase of self regulation. The present findings indicate that assessment concerns and locomotion concerns are clearly distinct in this phase, with individuals higher in assessment delving more into possible alternatives to past actions and individuals higher in locomotion engaging less in such reflective thought. What this suggests is that, separate from decreasing the amount of counterfactual thinking per se, individuals with locomotion concerns want to move on, to get on with it. Regret is about the past and not the future. Thus, individuals with locomotion concerns are less likely to experience regret. The results supported our predictions. We discuss the implications of these findings for the nature of regret and disappointment from the perspective of their relation to regulatory mode. Also, self regulatory mode and the specific emotions(disappointment and regret) were assessed and their influence on customers' behavioral responses(inaction, word of mouth) was examined, using a sample of 275 customers. It was found that emotions have a direct impact on behavior over and above the effects of negative emotions and customer behavior. Hence, We argue against incorporating emotions such as regret and disappointment into a specific response measure and in favor of a specific emotions approach on self regulation. Implications for services marketing practice and theory are discussed.

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A Study on Implementation of a Robot Vision System for Recogniton of complex 2-D Objects (복잡한 2차원 물체 인식용 로봇 시각장치의 구현에 관한 연구)

  • Kim, Ho-Seong;Kim, Yeong-Seok;Byeon, Jeung-Nam
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.1
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    • pp.53-60
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    • 1985
  • A computer vision system for robot is developed which can recognize a variety of two dimensional complex objects in gray level noisy scenes. the system is also capable of determining the position and orientation of the objects for robotlc manipulation. The hardware of the vision system is developed and a new edge tracking technique is also proposed. The linked edges are approximated to sample line drawing by split and merge algorithm. The system extracts many features from line drawing and constructs relational structure by the concave and convex hull of objects. In matching process, the input obhects are compared with the objects database which is formed by learning ability. Thelearning process is so simple that the system is very flexible. Several examples arc shown to demonstrate the usefulness of this system.

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Spillover Effects in Customer Incivility: Impacts on Frontline Employees' Negative Behaviors

  • Jung, Hyo Sun;Park, Young Mi;Yoon, Hye Hyun
    • Culinary science and hospitality research
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    • v.23 no.6
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    • pp.110-117
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    • 2017
  • This study intended to examine transitive relation among customer incivility perceived by deluxe hotel frontline employees, burnout, and deviant workplace behaviors and clarify the moderating effect of employees' stress. A total of 230 employees working in deluxe hotels in Seoul, the capital of Korea, in 2017 comprised the sample in this study. The hypothesized relationships in the model were tested simultaneously by using structural equation modelling (SEM). As results, customer incivility perceived by deluxe hotel frontline employees had significant (p<.001) positive influence on their burnout(${\beta}=.38$, t-value=4.93). Employees' burnout positively influenced their deviant workplace behaviors (${\beta}=.56$, t-value=7.22). In addition, customer incivility was found to positively affect employees' deviant workplace behaviors(${\beta}=.26$, t-value=3.90), and therefore, the moderating role of stress level was not verified. The findings of this study suggested that deluxe hotels are supposed to enhance their frontline service by providing orientation for customers through promotion materials. Limitations and future research directions of this study were also well established and discussed.

Korean Immigrant Women's Taekyo Practices in the United States as a Traditional Prenatal Self-care

  • Lee, Kyoung-Eun
    • Women's Health Nursing
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    • v.21 no.3
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    • pp.241-251
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    • 2015
  • Purpose: The purpose of this study was to explore preserved belief system supporting Korean immigrant women's Taekyo practices and influencing factors while they observe the tradition within US sociocultural context. Methods: Leininger's exploratory focused ethnographic approach was used. Semi-structured in-depth interviews were conducted with purposive sample of sixteen Korean immigrant women who gave birth in the US within last 6 months. Researcher's observation and reflective field notes were also integrated into the interview data. Leininger and McFarland's four phases of ethnographic analysis guided data analysis process. Results: The perceived belief system supporting Taekyo practices included Taekyo as an enculturated Korean tradition, connecting parents with fetus, and positive impacts on fetal development. And Korean immigrant women's Taekyo practices were influenced by resources of information, woman's orientation toward Taekyo, pressure from local Korean community, and child order. Conclusion: The findings from this research would serve as an important knowledge base to expand US health care providers' understanding of Korean traditional Taekyo practices observed by Korean immigrant women's as important prenatal self-care practices. The findings could also aid in providing more patient-centered and culturally-tailored prenatal care plan to Korean immigrant by including Korean traditional belief system supporting Taekyo practices.

A Study of Social Workers' Empowerment Level and Its Predictors : Cases of Social Workers in Community Welfare Centers (사회복지사의 임파워먼트에 영향을 미치는 요인에 관한 연구 : 지역사회복지관 사회복지사를 중심으로)

  • Kang, Chul-Hee;Yun, Min-Wha
    • Korean Journal of Social Welfare
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    • v.41
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    • pp.7-42
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    • 2000
  • Little empirical study has been conducted concerning social worker' empowerment that has very important function on clients' empowerment. Using the sample of 222 social workers selected from 92 community welfare centers, this study attempted to identify social workers' empowerment level and its predictors. This study used the empowerment scale developed by Leslie, Holzhalb, Holland (1998) that focuses on measurement of social workers's empowerment in social work agencies. Using confirmatory factor analysis, it was confirmed that the scale has three factors such as control of work environment, work relationships, and personal work orientation. This study showed that using 5 points scale, mean of social workers' empowerment is 3.67. In identifying predictors of the empowerment, this study used variables from the following aspects: organizational characteristics, job characteristics, and individual characteristics. Using regression analysis, it was found that variables related to job characteristics such as role ambiguities, role conflicts, and skill varieties are statistically very significant predictors of social workers' empowerment. Self-esteem in personal characteristics and participation in decision making and transformational leadership in organizational characteristics are also statistically significant predictors of social workers' empowerment. This study also revealed that self-control and self-esteem variables function as moderator in the relation with variables such as role ambiguities and role conflicts. Finally, this study discussed the direction of future research in social workers' empowerment and the areas that management efforts should be focused on for promoting social workers' empowerment.

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