• Title/Summary/Keyword: Critical Theory

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Development and Application of Educational Equipment for Vibration Engineering (진동공학 교육장비 개발 및 적용)

  • Rim, Kyung-Hwa;Yang, Xun
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.1 no.1
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    • pp.61-65
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    • 2009
  • Due to the less variety of experiment equipments for engineering education, the development of designated educational equipment is really in urgent need at most time. Especially for the in-depth engineering major subject, vibration engineering, there are almost no related educational equipments in Korea. Accordingly, in order to simulate the vibration phenomena occurred in the actual field, the development of educational equipment for vibration engineering theory and experiment education is required. This paper introduces four development educational equipments developed in graduated research works, which are critical speed test educational equipment, balancing machine educational equipment, isolation educational equipment using eddy current and active vibration isolation educational equipment. Through using them in experiment lesson, the utilization and practicality of educational equipment are verified. The proposed improvement for future development and application of educational equipment is shown in addition.

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Korean Immigrant Women's Meanings of Breast, Breast Cancer, and Breast Cancer Screenings

  • Suh Eun-Young Eunice
    • Journal of Korean Academy of Nursing
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    • v.36 no.4
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    • pp.604-611
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    • 2006
  • Purpose. Koreans are one of the fastest growing Asian populations in the U.S. since 1960s. In Korean immigrant women (KIW), breast cancer was reported as the most frequently diagnosed cancer. However, their screening rates for breast cancer are lower than national guidelines; it is assumed that underlying cultural schemas of breast, breast cancer, and its screening modalities exist and need to be studied. This study was aimed to investigate cultural meanings of breast, breast cancer, and breast cancer screenings in KIW. Methods. Using cultural models theory from cognitive anthropology, naturalistic qualitative methodology was utilized. Three focus group interviews with fifteen KIW were conducted. Thematic analysis with constant comparison technique was performed eliciting units of meaning, categories, and themes. Results. The cultural schema of the meaning of breast is 'mother who is breast-feeding her baby,' with two themes of 'balance in size,' and 'shyness.' Regarding breast cancer, three themes, i.e., 'indifference,' 'fear,' and 'uncertainty' are emerged. 'Lack of information about screening modalities' is the overarching schema with reference to breast cancer screenings. Conclusions. The findings of this study demonstrate unique cultural models of KIW related to breast cancer and its screenings, which are critical to understand and penetrate their barriers to breast cancer screening.

Afterlife with Image: Life and Death in Portraiture (이미지 속에서 살아남다? 초상화에서의 삶과 죽음)

  • Shin, Seung-Chol
    • The Journal of Art Theory & Practice
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    • no.16
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    • pp.139-174
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    • 2013
  • Pliny the Elder said that multiple cultures agree that the painting began as a shadow trace. A daughter of Butades, the potter in Corinth, traced an outline around a man's shadow, and it was the very beginning of painting. In this anecdote, the profile, i. e. the portrait substitutes body of the absent lover. It makes the absent body present and replaces his place. In this context Hans Belting put the anthropological value to this visual practice. Human being made images to cope actively with the shock of death and the disappearing of body. With the aid of the representation of the bodily presence, the image struggles to resist the death. This paper is a study on the critical meaning of representation in the context of bodily survival by image. The representation is the paradoxical trick of consciousness, an ability to see something as 'there' and 'not there' at the same time. So the connection between image and the body would be suspicious. Although this relation was tight in the ancient shadow painting and the medieval effigies, the modern visual practice forsakes this connection and exposes the trick of representation. It insists that image was not real and even expels the medieval visual practice from the boundary of fine arts. The genealogy of the portraiture is formed by two different visual practices. The belief and the disbelief in the image are observed in the process of representation and anti-representation, and this ambivalence transforms the ontological meaning of portrait in the visual representation.

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Plastic Deformation Behavior of Ti-51.5at.%Ni Shape Memory Alloy Single Crystals (Ti-51.5at.%Ni 형상기억합금 단결정의 소성변형 거동)

  • Jun, Joong-Hwan;Sehitoglu, Huseyin
    • Journal of the Korean Society for Heat Treatment
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    • v.15 no.1
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    • pp.9-15
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    • 2002
  • Deformation behavior of nickel-rich Ti-51.5at.%Ni single crystals was investigated over a wide range of temperatures(77 to 440K) and strain levels(up to 9%) in compression. These alloys combined superior strength with wide range of pseudoelasticity temperature interval(~200K). The slip deformation in [001] orientation did not occur due to the prevailing slip system, and consequently, exhibited pseudoelastic deformation at temperatures ranging from 77 to 283K and 273 to 440K for the solutionized and over-aged cases, respectively. The critical transformation stress levels were in the range of 800 to 1800MPa for the solutionized case, and 200 to 1000MPa for the over-aged case depending on the temperature and specimen orientation. These stress levels are considerably higher compared to these class of alloys having lower Ni contents. The maximum transformation strains, measured from incremental straining experiments in compression, were lower compared to the phenomenological theory with Type II twinning. A compound twinning model depending on the successive austenite(B2) to intermediate phase(R) to martensite(B19') transformation predicts lower transformation strains compared to the Type II twinning case.

The Effect of Sludge Settling Characteristics on Sludge-Water Interface Height Change Model (슬러지계면층 높이변화모델에서 슬러지 침전특성에 대한 영향)

  • Park, Suk Gyun;Kang, Seon-Hong
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.1
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    • pp.147-155
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    • 2006
  • For the further study of the solids flux theory, several researchers have proposed models to predict sludge settling velocity for each different concentration by using sludge indexes, SVI, SSVI and $SSVI_{3.5}$. It is difficult to apply the above models to predict sludge-water interface height in a batch column because sludge settling velocity changes while sludge settle down. While sludge settle down in a batch column, sludge concentration becomes high. The sludge concentration change is one of the most critical causes of the change of sludge settling velocity. Also, sludge concentration change causes of sludge index to change. SVI is more sensitive than SSVI or $SSVI_{3.5}$ to the change of sludge concentration. Each sludge has physical characteristics of its own which makes the settling velocity for each sludge different. The purpose of this study is to establish the correction factors that are able to compensate the errors derived from each different sludge settling characteristic by using sludge indexes, therefore the correction factors are applicable to the model for the change of sludge-water interface height.

Critical Factors Influencing Adoption of Cloud Computing for Government Organizations in Yemen

  • Salem, Mubarkoot Mohammed;Hwang, Gee-Hyun
    • Journal of Distribution Science
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    • v.14 no.11
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    • pp.37-47
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    • 2016
  • Purpose - Many countries nowadays look at cloud computing as an opportunity because it holds great advantages for governments. Public sector in Yemen still uses traditional computing. This study tends to explore the factors that would affect cloud computing adoption in government organizations in Yemen. Research design, data and methodology - We used a combination of DOI theory and TOE framework with some changes to suit the context of government organizations. Eight hypotheses were proposed with a questionnaire developed and sent to people in Yemen. 118 responses were collected to assess the hypotheses. Results - Results indicate that Yemen lacks some prerequisites of cloud technology in terms of technological readiness and regulations. The factors: relative advantage, compatibility, security concern, perception of benefits and government support were accepted. Perception of benefits, in particular, is found to affect the decision of adoption. Security concern also showed a direct and indirect influence on cloud adoption in the government. Respondents consider security a key issues of the technology. The factors: complexity, technology readiness and regulatory support were rejected. Conclusions - Based on all analysis results, this study proposed some steps toward adopting cloud computing in Yemen.

Vibration analysis of functionally graded nanocomposite plate moving in two directions

  • Arani, Ali Ghorbanpour;Haghparast, Elham;Zarei, Hassan BabaAkbar
    • Steel and Composite Structures
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    • v.23 no.5
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    • pp.529-541
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    • 2017
  • In the present study, vibration analysis of functionally graded carbon nanotube reinforced composite (FGCNTRC) plate moving in two directions is investigated. Various types of shear deformation theories are utilized to obtain more accurate and simplest theory. Single-walled carbon nanotubes (SWCNTs) are selected as a reinforcement of composite face sheets inside Poly methyl methacrylate (PMMA) matrix. Moreover, different kinds of distributions of CNTs are considered. Based on extended rule of mixture, the structural properties of composite face sheets are considered. Motion equations are obtained by Hamilton's principle and solved analytically. Influences of various parameters such as moving speed in x and y directions, volume fraction and distribution of CNTs, orthotropic viscoelastic surrounding medium, thickness and aspect ratio of composite plate on the vibration characteristics of moving system are discussed in details. The results indicated that thenatural frequency or stability of FGCNTRC plate is strongly dependent on axially moving speed. Moreover, a better configuration of the nanotube embedded in plate can be used to increase the critical speed, as a result, the stability is improved. The results of this investigation can be used in design and manufacturing of marine vessels and aircrafts.

Structural response of rectangular composite columns under vertical and lateral loads

  • Sevim, Baris
    • Steel and Composite Structures
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    • v.25 no.3
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    • pp.287-298
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    • 2017
  • The present study aims to determine the structural response of full scaled rectangular columns under both of vertical and lateral loads using numerical methods. In the study, the composite columns considering full concrete filled circular steel tube (FCFRST) and concrete filled double-skin rectangular steel tube (CFDSRST) section types are numerically modelled using ANSYS software. Vertical and lateral loads are applied to models to assess the structural response of the composite elements. Also similar investigations are done for reinforced concrete rectangular (RCR) columns to compare the results with those of composite elements. The analyses of the systems are statically performed for both linear and nonlinear materials. In linear static analyses, both of vertical and lateral loads are applied to models as only one step. However in nonlinear analyses, while vertical loads are applied to model as only one step, lateral loads are applied to systems as step by step. The displacement and stress changes in some critical nodes and sections and contour diagrams are reported by graphs and figures. At the end of the study, it is demonstrated that the nonlinear models reveal more accurate result then those of linear models. Also, it is highlighted that composite columns provide more and more safety, ductility compared to reinforced concrete column.

Present and Future Technologies of Satellite Communication Network Security (위성 통신망 보안 기술 당면 과제 및 향후 발전 방향 분석)

  • Choi, Jihwan;Joo, Changhee
    • Journal of Satellite, Information and Communications
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    • v.12 no.3
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    • pp.50-53
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    • 2017
  • Satellite communications are vulnerable to malicious eavesdroppers and interceptors due to wide coverage and broadcasting applications. However, technologies for securing satellite networks have yet to be more articulated beyond high-layer packet encryption. As attempts for jamming and spoofing attacks spread out, it is extremely critical to invest on the development of physical layer security solutions. In this paper, we review current technologies for satellite communication network security both in high and physical layers. We also present recent research results on physical layer security in the fields of information theory and wireless networks. We suggest a future direction for satellite communication security, including a cross-layer approach.

Investigation of the effect of surcharge on behavior of soil slopes

  • Aminpour, Mohammad Mahdi;Maleki, Mohammad;Ghanbari, Ali
    • Geomechanics and Engineering
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    • v.13 no.4
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    • pp.653-669
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    • 2017
  • By increase in the population and consequently constructions, new structures may be built in vicinity of the soil slopes. Such structures can be regarded as an extra surcharge on the slopes. The intensity and location of the surcharge affects the displacements of the slopes. Few researchers have studied the effect of surcharge on displacements of soil slopes. In this research, using limit analysis method and upper bound theory with non-associated flow rule, displacements of soil slopes in vicinity of a surcharge has been estimated. The authors have improved the technique previously proposed by them and a new formulation is suggested for calculating the permanent displacements of the soil slope in presence of a surcharge for two failure modes, rotational and transitional. A comparison has also been made between the two mentioned modes for various conditions of surcharge and slope. The conditions resulting in the rotational mode to be more critical than the transitional mode have been investigated. Also, the effects of surcharge's intensity, location of surcharge as well as the soil properties have been investigated.