• Title/Summary/Keyword: Structural Testing

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Effects of Systems Thinking on High School Students' Science Self-Efficacy (시스템 사고가 고등학생의 과학 자기 효능감에 미치는 영향)

  • Lee, Hyundong;Lee, Hyonyong
    • Journal of the Korean earth science society
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    • v.37 no.3
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    • pp.173-185
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    • 2016
  • The purpose of this study is to investigate the effects of systems thinking on high school students' self-regulatory efficacy and self-confidence that constitute science self-efficacy. We set self-regulatory efficacy as a factor of students' systems thinking affects their self-confidence on science through self-regulatory efficacy. A total of 210 students were sampled from general high schools and 188 valid cases were analyzed. The instrument has 39 items that consist of 20 items measuring systems thinking and 19 items of science self-efficacy. The result of the exploratory factor analysis indicated that 20 items for systems thinking, 8 items for self-regulatory efficacy, 4 items for self-confidence are reasonable. Testing the goodness of fit of a structural equation model, it turn out to be appropriate (${\chi}^2$=344.498, df=242, TLI= .921, RMSEA= .044) using 24 items (mental model, personal mastery, systems analysis, self-regulatory efficacy, and self-confidence were constructed). In addition, the mental model, which is one factor of systems thinking, is mediated by self-regulatory efficacy that affects self-confidence directly and/or indirectly. The results suggest that systems thinking affects science self-efficacy directly and indirectly. Utilizing systems thinking in science education can produce a theoretical basis in improving students' confidence and self-efficacy about science.

Development of Fiber Optic Total Reflected Extrinsic Fabry-Perot Interferometric Sensor for Structural Strain Measurement (구조물의 변형률 측정을 위한 광섬유 TR-EFPI 센서의 개발)

  • Kwon, In-Bum;Choi, Man-Yong;Moon, Hahn-Gue;Kim, Min-Soo
    • Journal of Sensor Science and Technology
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    • v.9 no.2
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    • pp.96-105
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    • 2000
  • Fiber optic TR-EFPI(total reflected extrtinsic Fabry-Perot interferometric) sensor was developed to measure the strain of structures, such as building, bridge, aircraft, etc. It has been difficult to distinguish the increase and decrease of the strain from the conventional fiber optic EFPI sensor because their signals only have a sinusoidal wave pattern related to the change of strain. Also, the absolute strain could not be measured by the simple fiber optic EFPI sensor. In this study, in order to measure the magnitude of strain with the direction of strain, the fiber optic sensor was simply constructed with the total reflected EFPI sensor probe. This probe was manufactured with a single mode fiber and a mirror coated fiber in a silica glass capillary tube. The output signal of this fiber optic TR-EFPT sensor can give the information about the magnitude and the direction of strain. The loading-unloading test was performed by the universal testing machine with alluminum beam specimen to compare the strain from fiber optic TR-EFPI sensor with the value from electrical strain gauge. In the result of this experiment. the strain from fiber optic TR-EFPI sensor had a good agreement with the values from the electrical strain gauge.

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Experimental Evaluation of Weathering Performance for Duplex Coating Systems Combining Thermal Spraying Metals and Painting (금속용사와 도장의 복합피복방식법에 대한 실험적 내후성능평가)

  • Kim, In Tae;Jun, Je Hyong;Cha, Ki Hyuk;Jeong, Young Soo;Ahn, Jin Hee
    • Journal of Korean Society of Steel Construction
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    • v.28 no.5
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    • pp.373-382
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    • 2016
  • Painting or thermally sprayed metal coating is often used in corrosion protection of steel structures. In recently, duplex coating system which combines thermally sprayed metals with paint is selected as a new generic type of coatings on steel structures under the highly corrosive environments. In this study, the structural steel specimens were surface treated, thermally sprayed with zinc, zinc-15%aluminum alloy, aluminum and aluminum-5%magnesium alloy, and finally sealing or painted with acrylic urethane. And as a reference specimens, steel specimens were painted with acrylic urethane after surface treatment. Circular defects with 1.0, 3.0 and 5.0 mm in diameters and line defect with 2.0 mm width, which reach the steel substrate were created on all specimens. The specimens were exposed into an environmental testing chamber controlled by the ISO 20340, which is a laboratory cyclic accelerated exposure test condition of spraying/UV/low temperature, for up to 175 days. Based on the corrosion tests, corrosion deterioration from the initial defects were evaluated and weathering performance of the specimens are compared.

An Empirical Study on R&D Effectiveness of IT SMEs (IT중소기업의 R&D시스템 효과성에 관한 실증연구 : 대구경북지역을 중심으로)

  • Shin, Jin-Kyo;Hwang, Su-Jung
    • Management & Information Systems Review
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    • v.28 no.4
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    • pp.109-129
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    • 2009
  • This study aims at investigating the effectiveness of SME's R&D system empirically. Specifically, this study analyze the relationships among R&D inputs(R&D investment, R&D human resource management), process(R&D planning, external network, internal cooperation), and output(technological innovation). A questionnaire was developed to measure the above variables. To test these relations, data were collected from the small and medium-sized IT firms located in Daegu-Kyungbuk region. The survey data of 154 firms were integrated as the empirical base for testing the relations. Most respondents were from the managers. Structural equation modeling analyses were used to examine the relations. Major results are as follows: Firstly, R&D HRM was positively and significantly influenced on the R&D planning. Secondly, R&D planning was positively and significantly affected on the external network, internal cooperation, and technological innovation. Thirdly, the both relations between R&D investment and R&D planning, and external network and technological innovation were not significant statistically. These results suggest the following implications. First, R&D human resource management is very important for IT SMEs. Secondly, internal cooperation mediates R&D inputs and technological innovation by approaching the other department's unique resources and by sharing the cost of new resource development. Several future researches need to overcome the limitations of this research. First, this study's sample was based on the small and medium-sized IT firms just located in Daegu-Kyungbuk region. This limitation may imply that empirical results can not represent overall small and medium-sized firm's situations. Therefore, future research needs to include different samples. Secondly, this study depends on the latitudinal study.

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Relationship between Transformational Leadership and Innovative Behavior (변혁적 리더십과 조직혁신간의 관계)

  • Ko, Hyon-Sook;Kim, Jung-Hoon
    • The Journal of the Korea Contents Association
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    • v.11 no.4
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    • pp.361-377
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    • 2011
  • This study has three primary purposes, firstly to identify how leader's personal characters influence to his/her transformational leadership, secondly to find how transformational leadership influences to innovative behavior, finally to explore how organizational cultures moderate between transformational leadership and innovative behavior. The first part of the study, based on literature study on transformational leadership, provides insight into what are antecedents, moderators and dependent variable in transformational leadership. Firstly, leader's personal characters are selected as antecedent variables such as extroversion and self-efficacy. Secondly, innovative behavior is introduced as a dependent variable. Thirdly, two types of organizational culture are considered as moderators between leader's personal character and leadership In this study, a comprehensive research model and hypothesis were empirically tested based on data from three types of questionnaires involving 663 employees in Korean organizations. In order to test the hypotheses, we have used Structural Equations Model (SEM) from AMOS7.0. In this analysis, we have employed raw data as it is instead of correlation matrix or covariance matrix. We have tested hypotheses by examining the significance of each path of the model, and gone through the process of testing the goodness of fit of the model itself. The results of statistical analysis show the following. Firstly, one of leader's personalities, self-efficacy has positive effect on his/her transformational leadership, but extroversion does not have positive effect. Secondly, transformational leadership has positive effect on innovative behavior. Finally, there was not any cultural moderating effects between transformational leadership and innovative behavior.

The Consideration for Optimum 3D Seismic Processing Procedures in Block II, Northern Part of South Yellow Sea Basin (대륙붕 2광구 서해분지 북부지역의 3D전산처리 최적화 방안시 고려점)

  • Ko, Seung-Won;Shin, Kook-Sun;Jung, Hyun-Young
    • The Korean Journal of Petroleum Geology
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    • v.11 no.1 s.12
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    • pp.9-17
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    • 2005
  • In the main target area of the block II, Targe-scale faults occur below the unconformity developed around 1 km in depth. The contrast of seismic velocity around the unconformity is generally so large that the strong multiples and the radical velocity variation would deteriorate the quality of migrated section due to serious distortion. More than 15 kinds of data processing techniques have been applied to improve the image resolution for the structures farmed from this active crustal activity. The bad and noisy traces were edited on the common shot gathers in the first step to get rid of acquisition problems which could take place from unfavorable conditions such as climatic change during data acquisition. Correction of amplitude attenuation caused from spherical divergence and inelastic attenuation has been also applied. Mild F/K filter was used to attenuate coherent noise such as guided waves and side scatters. Predictive deconvolution has been applied before stacking to remove peg-leg multiples and water reverberations. The velocity analysis process was conducted at every 2 km interval to analyze migration velocity, and it was iterated to get the high fidelity image. The strum noise caused from streamer was completely removed by applying predictive deconvolution in time space and ${\tau}-P$ domain. Residual multiples caused from thin layer or water bottom were eliminated through parabolic radon transform demultiple process. The migration using curved ray Kirchhoff-style algorithm has been applied to stack data. The velocity obtained after several iteration approach for MVA (migration velocity analysis) was used instead or DMO for the migration velocity. Using various testing methods, optimum seismic processing parameter can be obtained for structural and stratigraphic interpretation in the Block II, Yellow Sea Basin.

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Study on Hydrogen Embrittlement for API 5L X65 Steel Using Small Punch Test I : Base Metal (소형펀치 시험을 이용한 API 5L X65 강의 수소취화에 관한 연구 I : 모재부)

  • Jang, Sang-Yup;Yoon, Kee-Bong
    • Journal of Energy Engineering
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    • v.18 no.1
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    • pp.49-55
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    • 2009
  • Occurrence of hydrogen embrittlement could be one of the main obstacles for using structural equipment under hydrogen environment. It is required to develop assessment methods of hydrogen embrittlement for the metals used in production, storage, transmission and application utilities of hydrogen. The most probable method of hydrogen mass transmission is using existing natural gas pipeline. Base or weld part of the pipeline can be damaged by mixed gas of hydrogen in the pipeline. In this study small punch (SP) testing was employed to evaluate the hydrogen embrittlement behavior for a line pipe steel (API X65) with electrochemically hydrogen charged specimens. Results showed that the SP test can be a good candidate test method for hydrogen damage evaluation method. Strength of steel is known to be decreased with the level of hydrogen charging. However, for API X65 steel base metal need in this study, the effect of hydrogen to strength was not significant. It can be negligible regardless of the hydrogen contents in the steel. With this test different strength levels with various hydrogen charging conditions were observed. It can also be anticipated that more sensitive evaluation of material behavior be obtainable by the SP test method.

An efficient approach for model updating of a large-scale cable-stayed bridge using ambient vibration measurements combined with a hybrid metaheuristic search algorithm

  • Hoa, Tran N.;Khatir, S.;De Roeck, G.;Long, Nguyen N.;Thanh, Bui T.;Wahab, M. Abdel
    • Smart Structures and Systems
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    • v.25 no.4
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    • pp.487-499
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    • 2020
  • This paper proposes a novel approach to model updating for a large-scale cable-stayed bridge based on ambient vibration tests coupled with a hybrid metaheuristic search algorithm. Vibration measurements are carried out under excitation sources of passing vehicles and wind. Based on the measured structural dynamic characteristics, a finite element (FE) model is updated. For long-span bridges, ambient vibration test (AVT) is the most effective vibration testing technique because ambient excitation is freely available, whereas a forced vibration test (FVT) requires considerable efforts to install actuators such as shakers to produce measurable responses. Particle swarm optimization (PSO) is a famous metaheuristic algorithm applied successfully in numerous fields over the last decades. However, PSO has big drawbacks that may decrease its efficiency in tackling the optimization problems. A possible drawback of PSO is premature convergence leading to low convergence level, particularly in complicated multi-peak search issues. On the other hand, PSO not only depends crucially on the quality of initial populations, but also it is impossible to improve the quality of new generations. If the positions of initial particles are far from the global best, it may be difficult to seek the best solution. To overcome the drawbacks of PSO, we propose a hybrid algorithm combining GA with an improved PSO (HGAIPSO). Two striking characteristics of HGAIPSO are briefly described as follows: (1) because of possessing crossover and mutation operators, GA is applied to generate the initial elite populations and (2) those populations are then employed to seek the best solution based on the global search capacity of IPSO that can tackle the problem of premature convergence of PSO. The results show that HGAIPSO not only identifies uncertain parameters of the considered bridge accurately, but also outperforms than PSO, improved PSO (IPSO), and a combination of GA and PSO (HGAPSO) in terms of convergence level and accuracy.

A Study on Interorganizational Boundary Spanning Behaviors between Buyers and Sellers (유통경로 내 조직간 영역초월행동에 관한 연구)

  • Kim, Sang-Deok
    • Proceedings of the Korean DIstribution Association Conference
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    • 2007.08a
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    • pp.3-26
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    • 2007
  • Recently, both scholars and marketers have asserted the importance of boundary spanning behaviors, such as external representation, being vocal advocates to outsiders of the organization's image, goods, and services, internal influence, taking individual initiative in communications to the firm and co-workers to improve service delivery by the organization, co-workers, and oneself, and service delivery, serving customers in a conscientious, responsive, flexible, and courteous manner. However, there is lack of study dealing with bourdary spanning behaviors bewteen organizational dyads, in which boundary spanning behaviors are expected to have important roles. The objectives of this paper is to investigate these important concerns with prior research by developing a theoretical model predicting how distinct buyer's boundary spanning behaviors occur. To be concrete, this paper develops a seller characteristics-based model of the attitudinal antecedents of three conceptually distinct forms of boundary spanning behaviors, and tests the hypothesized differential effects of seller characteristics on the three forms of boundary spanning behaviors, and investigates the extent to which these relationships are mediated by relationship satisfaction and organizational commitment. For the purpose of empirical testing, 420 respondents of leading automobile dealers, dining franchisees, industrial material retailers in Korea were surveyed and the analysis utilizing structural equation model indicated that communication quality, fairness, and marketing program dynamism had positive effects on buyer's boundary spanning behaviors via relationship satisfaction and organizational commitment. In addition, boundary spanning behaviors occurred more in contractural and corporate distribution channel than in conventional distribution channel.

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The Roles of Economic Benefits and Identity Salience: Inducing Factors in the Behavioral Intent to Use Outlet Shopping Centers (아울렛 쇼핑센터의 이용의도에서 아이덴티티 현저성의 요인과 경제성의 역할)

  • Choi, Nak-Hwan;Lim, Ah-Young;An, Lina
    • Journal of Distribution Science
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    • v.11 no.6
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    • pp.41-50
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    • 2013
  • Purpose - Inducing consumers' behavioral intent to use an outlet shopping center is a critical issue for managers since it can be used as a guide for developing marketing strategies. Low prices could lead to a growth in retail purchases, but there might also be a positive relationship between prices and customer perceptions of product quality. The extent to which consumers use price as a predictor of quality may differ according to the availability of important alternative cues such as brand, store name, and identity salience triggered by the store. Consumers can obtain non-economic benefits from marketing exchanges that go beyond basic economic achievement. We argue that identity salience can play a crucial mediating role when consumers, acting as exchange partners, seek to obtain social benefits. This study shows that identity salience could mediate the relationship between identity salience-inducing factors such as multi-finality, prestige and role performance, and consumers' behavioral intent to use an outlet shopping center. Research design, data and methodology - The survey was conducted on college students enrolled in marketing classes. A total of 200 questionnaires were distributed, of which only 194 were returned. After five incomplete questionnaires were excluded, a final sample of 189 was used for empirical analysis. Using a covariance structural analysis in Amos17, we confirmed the fit of the research model and estimated its parameters by using the maximum likelihood method. Results - The results of the hypotheses testing are as follows. First, both identity salience and economic benefits have positive effects on the behavioral intent to use an outlet shopping center. Second, role performance, prestige, and multi-finality have positive effects on identity salience. Finally, the additive analysis of the direct effects of identity salience-inducing factors shows that the role performance, prestige, and multi-finality factors have no direct effects on the behavioral intent to use an outlet shopping center, suggesting that identity salience plays a positive mediating role. Conclusions - This study informs marketers that not only price but shoppers' identity salience directly affects their intent to visit an outlet shopping center. To strengthen shoppers' identity salience, marketers should find ways to help shoppers fulfill their multiple social roles, realize their multiple goals, and achieve prestige. In other words, outlet shopping centers must improve their personal service environment in order to enhance their employees' service quality and assist the execution of multi-finality by minimizing the perceived costs (e.g., travel time, effort) associated with shopping trips, thus making it easier for consumers to combine visits to multiple stores in outlet shopping centers and buy the items required for their consumption goals. Outlet shopping centers must also offer assortments with both breadth and depth in order to help consumers play the social roles their social networks have given them.