• Title/Summary/Keyword: Critical Theory

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Stability and dynamic analyses of SW-CNT reinforced concrete beam resting on elastic-foundation

  • Bourada, Fouad;Bousahla, Abdelmoumen Anis;Tounsi, Abdeldjebbar;Bedia, E.A. Adda;Mahmoud, S.R.;Benrahou, Kouider Halim;Tounsi, Abdelouahed
    • Computers and Concrete
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    • v.25 no.6
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    • pp.485-495
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    • 2020
  • This paper, presents the dynamic and stability analysis of the simply supported single walled Carbon Nanotubes (SWCNT) reinforced concrete beam on elastic-foundation using an integral first-order shear deformation beam theory. The condition of the zero shear-stress on the free surfaces of the beam is ensured by the introduction of the shear correction factors. The SWCNT reinforcement is considered to be uniform and variable according to the X, O and V forms through the thickness of the concrete beam. The effective properties of the reinforced concrete beam are calculated by employing the rule of mixture. The analytical solutions of the buckling and free vibrational behaviors are derived via Hamilton's principle and Navier method. The analytical results of the critical buckling loads and frequency parameters of the SWCNT-RC beam are presented in the form of explicit tables and graphs. Also the diverse parameters influencing the dynamic and stability behaviors of the reinforced concrete beam are discussed in detail.

A Study on Antecedents of SNS User's Addiction in the Age of Convergence: The Role of SNS Habit (융복합 시대에 소셜 네트워크 서비스 사용자들의 중독 요인에 대한 연구: 습관의 역할)

  • Kim, Byoung-Soo;Kim, Dae-Kil
    • Journal of Digital Convergence
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    • v.13 no.8
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    • pp.161-168
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    • 2015
  • Given social problems of social network service (SNS) addiction, it is critical to understand user's formation mechanism of SNS addiction. Since a number of studies have demonstrated the negative outcomes of excessive SNS use, the researchers examined important antecedents of SNS addiction as SNS habit that is considered as a key driver of SNS addiction. Moreover, the effects of self-expression, network management, and information search on SNS addition formation were investigated. The proposed theoretical model was empirically tested by using longitudinal survey data collected from 206 Facebook users. The analysis results indicate that SNS habit plays an important role in forming SNS addiction. Further, self-expression, network management, and information search influence SNS addiction through SNS habit. The analysis results offer some in-depth perspectives to SNS providers and government that establish policies or digital convergence strategies to induce healthy SNS use.

For the Deconstruction of the History of Western Architecture as a Discourse - A Reflection on the Education of the Architectural History in Korea - (우리 서양건축사 교육의 반성 - 담론으로서 '서양건축사'를 해체하기 위하여 -)

  • Khang, Hyuk
    • Journal of architectural history
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    • v.20 no.6
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    • pp.57-76
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    • 2011
  • This study is on the pedagogical convention of architectural history in Korea, especially that of Western Architecture. Recent institutional change in architectural school in Korea has caused overall restructuring of academic program. In spite of extension in the field of history there was no progress of method and way of thinking. There is no change in the point of view to see the western architecture and its history as a unique and specialized phenomenon in the civilization of mankind. Because of no recognition about for what, for whom, and how to, and because of orientalism, the cultural position of western architectural history and its narrative was not asked. With the help of post-colonialism, de-constructivism and critical historiography this paper tries to show the fundamental premise of western architectural history as a myth and show its prejudice as not being justifiable. The background of the discourse there has been a representation effect with regard to knowledge as a power. we need to escape from this kind of cognitional frame With the analysis of the its premise and narrative we can find it is a historical construct that was made in the age of imperialism. In fact it has a lot of false information and problematic point of view. The Identity and originality of western architecture and its history has no logical reason or foundation if we think that it depends on the difference and comparison with other civilization. For example the explanation of its historical origin western architecture has big difference with Islamic architecture in spite of the resemblance each other. This paper try to show several reasons that discourse of western architectural history can not be survived any longer. So we need to reconstruct new pedagogy with deconstruction for the students of non western, or Korean students. Because it has important effect to see and think about architecture and its history.

A Study on Salesperson Brand Relationships, Customer Orientation, and Customer Store Loyalty (판매원 브랜드 관계, 고객 지향성 및 고객 점포 충성도에 관한 연구)

  • Choi, Soonhwa
    • Journal of Distribution Science
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    • v.16 no.11
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    • pp.57-64
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    • 2018
  • Purpose - As the importance of salesperson attitudes and behaviors enhancing customer perception and loyalty have increased, many retail companies put emphasis on internal marketing activities. The issue also has captured the interest of academics, but most of the previous research tends to be limited to investigating antecedents of salesperson job satisfaction and commitment. Based on the consumer-brand relationship concepts, this study aims to examine the effects of the salesperson-brand relationships on customers' service evaluation and store loyalty. Research design, data, and methodology - In a structural equation model, it is hypothesized that salesperson brand identification influences salespersons' brand trust and affect, which are the two dimensions of consumer-brand relationships. Salespersons' brand trust and affect are expected to increase salespersons' customer orientation, which in turn influences customers' service evaluations and store loyalty. To test this hypotheses a set of data collected from department stores in Seoul is utilized. Results - First, it was found that salesperson brand identification is a significant antecedent to salespersons' brand trust and affects, the two dimensions of salesperson brand relationships. Second, salespersons' brand trust and affect were found to enhance salespersons' customer-oriented behaviors. Third, salespersons' customer orientation showed a significant effect on customers' service evaluation. When a salesperson makes more effort to provide useful information for fulfilling customer needs, customers evaluate the salesperson's service more positively. Finally, customers' service evaluation had a positive impact on customers' store loyalty. Conclusions - This study provides significant academic and practical implications. First, based on the theory of consumer-brand relationships, the concept of salesperson-brand relationships was introduced and found to be an effective motivator of salespersons' customer oriented attitudes and behaviors. Therefore, the two dimensions of brand relationships, brand trust and affect, should be considered as the critical factors both in developing theoretical research and improving long-term company performance. Also, internal marketing activities should focus on maximizing employees' brand identification. That is, retail companies need to put emphasis on sharing their brand values and personality with internal customers to strengthen the brand relationships with salespersons and to enhance customer responses.

The Factors Influencing the Determination of a Business Indicators for Urban Regeneration Based on Jinju City - Focused on collective memory theory - (진주시 도시재생사업지표 결정에 영향을 미치는 요인 도출 - 집단기억 이론을 중심으로 -)

  • Lee, So-Yeong;Joo, Hee-Sun
    • Journal of the Korean Institute of Rural Architecture
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    • v.21 no.4
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    • pp.17-24
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    • 2019
  • It has been long time since the local small-and-medium cities had lost their vitality due to the progress of aging, economic decline in urban areas, the lack of new growth engines, and the declining population in korea. In addition, since the implementation of the local self-governing system, the creation of new urban areas and the transfer of the administrative institutions to the outskirts of a city have accelerated the decline of old downtown. Rather, local small-and-medium cities would have a problem to make urban regeneration impossible. Under the recognition of such problems, individual self-governing entities have come up with numerous policies and implemented various policies for the revitalization of local small-and-medium cities, but it is a condition that the effect of their efforts falls shorts of expectations, such as the space of the similar style, which has been widespread in developed countries, simple restoration, and a few structural changes. In this regard, the part to be realized anew is to enhance the attractiveness of small-and-medium cities. However, is not possible to raise the overall attractiveness in a short time in reality. To select local assets to be utilized in urban regeneration, it is judged that gathering opinions of local residents is more important than any other thing. Accordingly, this study intends to present positive outcome for the purpose of the revitalization of local small-and-medium cities by finding the factors which can remind us of the collective memory of Jinju city and selection the critical factors to determine a detailed project plan from the perspective of urban regeneration.

Relationships between Sedation Knowledge and Nurse Practice Competences in Intensive Care Unit (집중치료실 간호사의 진정요법 지식과 간호실무 역량요인의 상관성 분석)

  • Jang, Hyejoo;Lee, JuHee;Nam, Ae-Ri-Na;Kim, Heejung
    • Journal of Korean Clinical Nursing Research
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    • v.24 no.1
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    • pp.74-84
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    • 2018
  • Purpose: For this study an examination was done of relationships between intensive care unit (ICU) nurses' knowledge related to sedation and their clinical competencies in sedation practice. Methods: Ninety one ICU nurses were recruited from two tertiary hospitals in South Korea. A self-report questionnaire was used to examine the levels of knowledge related to sedation and nursing practice competence based on Ajzen's theory of planned behavior. Descriptive statistics, independent t-tests, one-way ANOVA, and Pearson correlations were performed using the IBM SPSS 21.0 Results: ICU nurses are more knowledgeable about general information on sedation rather than up-to-date information. Continuing education on sedation was related to difference in knowledge levels. However, the levels of knowledge were not related to competence in sedation practice. Instead, a positive attitude toward sedation practice was significantly related to the subjective norms; orders and goals, perceived behavioral control, practice of sedation, and intention to use. Conclusion: The results of this study provide fundamental information on levels of knowledge related to sedation practices of Korean ICU nurses. Continuing education should emphasize up-to-date information on sedation practice and need for positive attitudes which influence all other competencies towards sedation practices to achieve optical care of sedation in the ICU.

A study on early faults detection of pressurizer pressure control system using MTS (MTS를 이용한 가압기 압력 제어 계통의 조기 고장 감지에 대한 연구)

  • Cha, Jae-Min;Kim, Joon-Young;Shin, Junguk;Yeom, Choongseob;Kang, Seong-Ki
    • The Korean Journal of Applied Statistics
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    • v.29 no.7
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    • pp.1385-1398
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    • 2016
  • A pressurizer is a major equipment system in a nuclear power plant (NPP) and controls the reactor cooling system pressure within the allowable range. Faults in the pressurizer can be critical to the NPP; therefore, early fault detection in the pressurizer is significant for NPP safety. This study applies Mahalanobis Taguchi system (MTS), which is one of the promising pattern classification methods, based on the Mahalanobis distance concept and Taguchi quality engineering theory to the early fault detection problem of the pressurizer pressure control system. We conducted experiments using data from full scope NPP simulator based on a pressurizer pressure transmitter faults scenario to validate the faults detection performance of MTS. As a result, MTS can rapidly detect the faults compared to conventional faults detection based on single sensor monitoring.

Scramjet Research at JAXA, Japan

  • Chinzei Nobuo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.1-1
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    • 2005
  • Japan Aerospace Exploration Agency(JAXA) has been conducting research and development of the Scramjet engines and their derivative combined cycle engines as hypersonic propulsion system for space access. Its history will be introduced first, and its recent advances, focusing on the engine performance progress, will follow. Finally, future plans for a flight test of scramjet and ground test of combined cycle engine will be introduced. Two types of test facilities for testing those hypersonic engines. namely, the 'Ramjet Engine Test Facility (RJTF)' and the 'High Enthalpy Shock Tunnel (HIEST)' were designed and fabricated during 1988 through 1996. These facilities can test engines under simulated flight Mach numbers up to 8 for the former, whereas beyond 8 for the latter, respectively. Several types of hydrogen-fueled scramjet engines have been designed, fabricated and tested under flight conditions of Mach 4, 6 and 8 in the RJTF since 1996. Initial test results showed that the thrust was insufficient because of occurrence of flow separation caused by combustion in the engines. These difficulty was later eliminated by boundary-layer bleeding and staged fuel injection. Their results were compared with theory to quantify achieved engine performances. The performances with regards to combustion, net thrust are discussed. We have reached the stage where positive net thrust can be attained for all the test coditions. Results of these engine tests will be discussed. We are also intensively attempting the improvement of thrust performance at high speed condition of Mach 8 to 15 in High Enthalpy Shock Tunnel (HIEST). Critical issues for this purposemay be air/fuel mixing enhancement, and temperature control of combustion gas to avoid thermal dissociation. To overcome these issues we developed the Hypermixier engine which applies stream-wise vortices for mixing enhancement, and the M12-engines which optimizes combustor entrance temperature. Moreover, we are going to conduct the flight experiment of the Hypermixer engine by utilizing flight test infrastructure (HyShot) provided by the University of Queensland in fall of 2005 for comparison with the HIEST result. The plan of the flight experiment is also presented.

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Improving Lock Performance of Home-base Lazy Release Consistency (Home-based Lazy Release Consistency의 락 성능향상)

  • Yun, Hui-Cheol;Lee, Sang-Gwon;Lee, Jun-Won;Maeng, Seung-Ryeol
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.10
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    • pp.513-519
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    • 2001
  • Home-based Lazy Release Consistency (HLRC) shows poor performance on lock based applications because of two reasons:(1) a whole page is fetched on a page fault while actual modification is much smaller , and(2) the home is at the fixed location while access pattern is migratory, In this paper we present an efficient lock protocol for HLRC. In this protocol, the pages that are expected to be used by acquirer selectively updated using diffs. The diff accumulation problem is minimized by limiting the size of diffs to be sent for each page. Our protocol reduces the number or page faults inside critical sections because pages can be updated by applying locally stored diffs . This reduction yields the reduction of average lock waiting time and the reduction of message amount. The experiment with five applications shows that our protocol archives 2%~40% speedup against base HLRC for four applications.

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The Study of the Cycle Time Improvement by Work-In-Process Statistical Process Control Method for IC Foundry Manufacturing

  • Lin, Yu-Cheng;Tsai, Chih-Hung;Li, Rong-Kwei;Chen, Ching-Piao;Chen, Hsien-Ching
    • International Journal of Quality Innovation
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    • v.9 no.3
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    • pp.71-91
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    • 2008
  • The definition of cycle time is the time from the wafer start to the wafer output. It usually takes one or two months to get the product since customer decides to produce it. The cycle time is a critical factor for customer satisfaction because it represents the response time to the market. Long cycle time reflects the ineffective investment for the capital. The cycle time is very important for foundry because long cycle time will cause customer unsatisfied and the order loss. Consequently, all of the foundries put lots of human source in the cycle time improvement. Usually, we make decisions based on the experience in the cycle time management. We have no mechanism or theory for cycle time management. We do work-in-process (WIP) management based on turn rate and standard WIP (STD WIP) set by experiences. But the experience didn't mean the optimal solution, when the situation changed, the cycle time or the standard WIP will also be changed. The experience will not always be applicable. If we only have the experience and no mechanism, management will not be work out. After interview several foundry fab managers, all of the fab can't reflect the situation. That is, all of them will have an impact period after product mix or utilization varied. In this study, we want to develop a formula for standard WIP and use statistical process control (SPC) concept to set WIP upper/lower limit level. When WIP exceed the limit level, it will trigger action plans to compensate WIP Profile. If WIP Profile balances, we don't need too much WIP. So WIP level could be reduced and cycle time also could be reduced.