• Title/Summary/Keyword: response effectiveness

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Seismic response distribution estimation for isolated structures using stochastic response database

  • Eem, Seung-Hyun;Jung, Hyung-Jo
    • Earthquakes and Structures
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    • v.9 no.5
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    • pp.937-956
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    • 2015
  • Seismic isolation systems decouple structures from ground motions to protect them from seismic events. Seismic isolation devices have been implemented in many full-scale buildings and bridges because of their simplicity, economic effectiveness, inherent stability, and reliability. It is well known that the most uncertain aspect for obtaining the accurate responses of an isolated structure from seismic events is the seismic loading itself. It is needed to know the seismic response distributions of the isolated structure resulting from the randomness of earthquakes when probabilistic designing or probabilistic evaluating an isolated structure. Earthquake time histories are useful and often an essential element for designing or evaluating isolated structures. However, it is very challenging to gather the design and evaluation information for an isolated structure from many seismic analyses. In order to evaluate the seismic performance of an isolated structure, numerous nonlinear dynamic analyses need to be performed, but this is impractical. In this paper, the concept of the stochastic response database (SRD) is defined to obtain the seismic response distributions of an isolated structure instantaneously, thereby significantly reducing the computational efforts. An equivalent model of the isolated structure is also developed to improve the applicability and practicality of the SRD. The effectiveness of the proposed methodology is numerically verified.

A Comparison of Free Response Items and Multiple Choice Items in Terms of Effectiveness of Estimating Mathematical Ability (수행형 문항과 선다형 문항의 수학적 능력 추정 효율성 비교)

  • Park, Jung;Park, Kyung-Mi
    • The Mathematical Education
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    • v.43 no.2
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    • pp.151-162
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    • 2004
  • For the past several years, performance assessment has been widely used by mathematics teachers. The superiority of performance assessment items compare to multiple choice items has been discussed by many researchers, however these discussions tend to be lack of empirical data. Thus, this study aims to examine the effectiveness of tree response items in comparison with multiple choice items. Using the information function in Item Response Theory(IRT), item information of free response items and multiple choice items from the Third International Mathematics and Science Study-Repeat(TIMSS-R) were obtained and compared. Test informations of the whole mathematics area as well as each content area of mathematics were computed. On average, tree response items yielded more information than multiple choice items, especially in measurement and data interpretation. This study also revealed that free response items estimated students' mathematics ability more accurately than multiple choice items with smaller number of items.

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The Response to Impulse Signal on Three Phase Transformer using Vector Network Analyzer (벡터 회로망 분석기 측정을 기반으로 한 3상 변압기의 시간영역 펄스 신호에 대한 응답 분석)

  • Kim, Kwangho;Jung, Jongman;Nah, Wansoo
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.79-84
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    • 2015
  • Transformer is widely used element on power system and industrial area. Especially the transformers installed at power system are exposed to an environment of arbitrary changed. Thus the prediction of degradation and the analysis of response to impulse are important. To conduct those works, the electrical characteristics of system should be analyzed, effectively. But the analysis of electrical characteristic in electric machine level such as pole and pad-mounted transformer is almost no, thus commercial VNA (Vector Network Analyzer) is used to getting the response in wide frequency range. However, the output power of VNA is usually under 10mW, so verification for effectiveness of measuring electrically large component should be conducted, firstly. Next, after getting total S-parameter of transformer, predicting impulse response can be performed in time-domain with circuit simulator. In this paper, it is introduced that verification effectiveness of VNA using transfer function from SFRA (Sweep Frequency Response Analyzer), firstly. Next, total S-parameter, six by six matix form, was built using measured 2 port S-parameter from vector network analyzer. To get the response to impulse which is defined by IEC 60060-1, time-domain simulation is conducted to ADS (Advenced Design System) circuit simulator.

Performance Evaluation of Smart Intersections for Emergency Response Time based on Integration of Geospatial and Incident Data

  • Oh, Heung Jin;Ashuri, Baabak
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.945-951
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    • 2022
  • The major objective of this research is to evaluate performance of improved intersections for response time to emergency vehicle preemption. Smart technologies have been introduced to civil infrastructure systems for resilient communities. The technologies need to evaluate their effectiveness and feasibility to confirm their introduction. This research focuses on the performance of emergency vehicle preemption, represented by response time, when smart intersections are introduced in a community. The response time is determined by not only intersections but also a number of factors such as traffic, distance, road conditions, and incident types. However, the evaluation of emergency response has often ignored factors related to emergency vehicle routes. In this respect, this research synthetically analyzes geospatial and incident data using each route of emergency vehicle and conducts before-and-after evaluations. The changes in performance are analyzed by the impact of smart intersections on response time through Bayesian regression models. The result provides measures of the project's performance. This study will contribute to the body of knowledge on modeling the impacts of technology application and integrating heterogeneous data sets. It will provide a way to confirm and prove the effectiveness of introducing smart technologies to our communities.

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Interaction Effects of Arousal Level of Positive Ambient Emotion and Advertisement Type on Product Evaluation

  • Choi, Nak Hwan;Oyunbileg, Tamir
    • Asia Marketing Journal
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    • v.18 no.1
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    • pp.37-53
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    • 2016
  • The purpose of this study is to show that the effectiveness of utilitarian versus hedonic attributefocused advertisement on product evaluation depends on the arousal level of positive emotion, and to explore mediation effect of cognitive response to utilitarian attribute-focused advertisement and affective response to hedonic attribute-focused advertisement on the effectiveness of utilitarian versus hedonic attribute-focused advertisement. This research employs a 2 (arousal level: mild vs. elevated) × 2 (advertisement type: utilitarian vs. hedonic) between-subjects design, and 200 undergraduate students participate in the experiment, in which there are 50 students at each experimental group. The results of ANCOVA with positive emotion level as a covariate on advertised product evaluation show significant interaction effect of arousal level and advertisement type, and no effect of positive emotional level. Both of the mediation effects of the cognitive response and those of the affective response are significant. Participants under mild (elevated) arousal of positive emotion more positively evaluate the product in utilitarian (hedonic) attribute-focused advertisement. The positive effect of utilitarian (hedonic) attributefocused advertisement on product evaluation is partially mediated by cognitive (affective) response to the advertisement when consumers are under the mild (elevated) arousal of positive emotion. The results of this study show that advertisers should use utilitarian (hedonic) attribute-focused advertisement to consumers under the mild (elevated) arousal of ambient positive emotion, which should be searched by exploring what kind of event they have experienced.

An Application of DoE Methodology in WAVE Simulation to Identify the Effectiveness of Variables on Engine Performance and to Optimize Responses (실험계획법과 WAVE 시뮬레이션을 이용한 엔진 작동 변수의 영향도 평가 및 최적화에 대한 연구)

  • Jeong, Dong-Won;Lim, Ock-Taeck
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.5
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    • pp.16-25
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    • 2009
  • Testing engine performance using an engine dynamometer requires high technical researchers and many facilities. Nowadays, different variables of CAE program are used for identifying the engine performance instead of engine dynamometer test. This is more convenience, as it does not necessitate an abundance of engine dynamometer experiments and, in addition, produces better results. However, CAE programs also contain various variables which can affect engine performance. Those are coupled with each other, thus making it difficult to determine the effectiveness of different variables on engines. DoE (Design of Experiments) methodology is an efficient way to verify the magnitude of effectiveness on engine performance as well as making responses to be optimized at once without trial & error. This study used data from WAVE simulations, which modeled the DOHC SI engine with in-line 4 cylinders at 1500, 3000 and 4500rpm. DoE methodology is designed properly to determine the effectiveness of five variables on power, BSFC, and volumetric efficiency, as well as to find the optimal response conditions at each rpm through a minimized number of experiments. After finishing DoE process, all the results are examined concerning the reliability of test through a verification experiment.

Seismic control of structures using sloped bottom tuned liquid dampers

  • Bhosale, Amardeep D.;Murudi, Mohan M.
    • Structural Engineering and Mechanics
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    • v.64 no.2
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    • pp.233-241
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    • 2017
  • Earlier numerous studies have been done on implementation of Tuned Liquid Damper (TLD) for structural vibration control by many researchers. As per current review there is no significant study on a sloped bottom TLD. TLD's are passive devices. A TLD is a tank rigidly attached to the structure and filled partially by liquid. When fundamental linear sloshing frequency is tuned to structure's natural frequency large sloshing amplitude is expected. In this study set of experiments are conducted on flat bottom and sloped bottom TLD at beach slope $20^{\circ}$, $30^{\circ}$ and $45^{\circ}$, for different types of structures, mass ratio, and depth ratio to investigate the overall effectiveness of TLD and specific effect of TLD parameters on structural response. This experimental study shows that a properly designed TLD reduces structural response. It is also observed that effectiveness of TLD increases with increase in mass ratio. In this experimental study an effectiveness of sloped bottom TLD with beach slope $30^{\circ}$ is investigated and compared with that of flat bottom TLD in reducing the structural response. It is observed from this study that efficiency of sloped bottom TLD in reducing the response of structure is more as compared to that of flat bottom TLD. It is shown that there is good agreement between numerical simulation of flat bottom and sloped bottom TLD and its experimental results. Also an attempt has been made to investigate the effectiveness of sloped bottom TLD with beach slope $20^{\circ}$ and $45^{\circ}$.

Small scale experimental testing to verify the effectiveness of the base isolation and tuned mass dampers combined control strategy

  • Petti, Luigi;Giannattasio, Giovanni;De Iuliis, Massimiliano;Palazzo, Bruno
    • Smart Structures and Systems
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    • v.6 no.1
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    • pp.57-72
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    • 2010
  • This paper presents the most significant results obtained within a broad-ranging experimental program aiming to evaluate both the effectiveness and the robustness of a Base Isolation (BIS) and a Tuned Mass Damper (TMD) combined control strategy (BI & TMD). Following a brief description of the experimental model set-up and the adopted kinematic scaling technique, this paper describes the identification procedures carried out to characterize the system''s model. The dynamic response of a small-scale model to recorded earthquake excitations, which has been scaled by using the Buckingham pi-theorem, are later presented and discussed. Finally, the effectiveness and robustness of the combined control strategy is evaluated by comparing the model's dynamic response. In particular, reduction in relative displacements and absolute accelerations due to the application of different mass damping systems is investigated.

System Infrastructure of Efficient Web Cluster System to Decrease the Response Time using the Load Distribution Algorithm (부하분산 알고리즘을 적용하여 반응시간을 감소시키는 웹 클러스터 시스템 구축)

  • Kim Seok-chan;Rhee Young
    • Journal of KIISE:Computing Practices and Letters
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    • v.10 no.6
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    • pp.507-513
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    • 2004
  • In this paper, we consider the methodology of efficient resource usage, specially web clustering system. We develope an algorithm that distributes the load on the web cluster system to use the system resources, such as system memory equally. The response time is chosen as a performance measure on the various clustering models. And based on the concurrent user to the web cluster system, the response time is also examined as the number of users increases. Simulation experience with this algorithm shows that the response time seems to have a good results compare to those with the other algorithm. And, also the effectiveness of clustered system becomes better as long as the number of concurrent user increases. The usage of developed algorithm is more useful when the system consists of many different sub-systems, a heterogeneous clustering system.

Force-based seismic design of steel haunch retrofit for RC frames

  • Ahmad, Naveed
    • Earthquakes and Structures
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    • v.20 no.2
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    • pp.133-148
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    • 2021
  • The paper presents a simplified force-based seismic design procedure for the preliminary design of steel haunch retrofitting for the seismic upgrade of deficient RC frames. The procedure involved constructing a site-specific seismic design spectrum for the site, which is transformed into seismic base shear coefficient demand, using an applicable response modification factor, that defines base shear force for seismic analysis of the structure. Recent experimental campaign; involving shake table testing of ten (10), and quasi-static cyclic testing of two (02), 1:3 reduced scale RC frame models, carried out for the seismic performance assessment of both deficient and retrofitted structures has provided the basis to calculate retrofit-specific response modification factor Rretrofitted. The haunch retrofitting technique enhanced the structural stiffness, strength, and ductility, hence, increased the structural response modification factor, which is mainly dependent on the applied retrofit scheme. An additional retrofit effectiveness factor (ΩR) is proposed for the deficient structure's response modification factor Rdeficient, representing the retrofit effectiveness (ΩR=Rretrofitted /Rdeficient), to calculate components' moment and shear demands for the retrofitted structure. The experimental campaign revealed that regardless of the deficient structures' characteristics, the ΩR factor remains fairly the unchanged, which is encouraging to generalize the design procedure. Haunch configuration is finalized that avoid brittle hinging of beam-column joints and ensure ductile beam yielding. Example case study for the seismic retrofit designs of RC frames are presented, which were validated through equivalent lateral load analysis using elastic model and response history analysis of finite-element based inelastic model, showing reasonable performance of the proposed design procedure. The proposed design has the advantage to provide a seismic zone-specific design solution, and also, to suggest if any additional measure is required to enhance the strength/deformability of beams and columns.