• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.476-488
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• 2016

This study reviewed factors and causes that affect on reliability and accuracy of transportation demand forecasting. In general, the causes of forecasting errors come from variety and irregularity of trip behaviors, data limitation, data aggregation and model simplification. Theoretical understanding about the inevitable errors will be helpful for reasonable decision making for practical transportation policies. The study especially focused on traffic assignment with the KTDB data, and described the factors and causes of errors by classifying six categories such as (1) errors in input data, (2) errors due to spacial aggregation and representation method of network, (3) errors from representing values for variations of traffic patterns, (4) errors from simplification of traffic flow model, and (5) errors from aggregation of route choice behavior.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.455-466
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• 2003

A self-selected web survey was utilised to Investigate the preference of online holiday travellers to the Internet functions applied to the extensive decision-making process by adoptingthe Canberra tourism website as a case study in Australia. The use of web-based surveys is not at a mature stage, compared to other traditional surveys such as mail survey and telephone survey that have already-known home addresses and phone numbers as a frame population. The adopted web survey relies on non-probability sampling without a known frame population thatcan cause serious research errors. Therefore, the results of this study need to be compared to other official published statistics in order toverify reliability or credibility of the self-selected web survey. This study discusses the extent to which the self-selected web survey can be validated by finding the significant difference not only between the demographic results of web survey and those of official statistics released by several articles including the Graphic, Visualizations and Usability Center (GVU) at Georgia Tech research but also between the travel background features and those of ‘ACT Tourism Masterplan 2001-2005’published by the Canberra Tourism ＆ Event Corporation (CTEC) located in Australian Capital Territory (ACT).

• The Research Journal of the Costume Culture
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• v.26 no.5
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• pp.649-664
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• 2018

With the rapid growth of the Chinese cosmetics market and the continuous introduction of new products into the market, beauty videos generated by other consumers, that are by beauty vloggers, have become a major source of information for cosmetics consumers. With the popularity of beauty vlogs in China, beauty vloggers have become influencers who affect consumers' information processing and attitude development regarding cosmetic products and beauty routines. The current study aims to explore the characteristics of beauty vloggers that affect consumers' attitudes toward both the beauty vlogs and the products featured in those vlogs. Based on parasocial interaction theory, the study examines whether perceived characteristics of beauty vloggers influence consumers' perceived parasocial interaction, which in turn influences their attitudes. The study employs an online survey, which was administered to female consumers in China. Data from a total of 372 responses was used for analysis. Findings show that the perceived similarities to and perceived trustworthiness of vloggers have a significant impact on parasocial interactions, which influences consumer attitudes toward both the vlogs and the products shown in them. Perceived reliability and perceived attractiveness are shown to have a positive impact on consumer attitudes toward vlogs. Perceived expertise, attractiveness, similarity, and trustworthiness have all been shown to affect product attitudes. These results show that while beauty vlogs have a significant impact on consumers' decision-making processes, the perceived characteristics of beauty vloggers themselves are important to consumers in the development of their attitudes toward both vlogs and products.

• Nuclear Engineering and Technology
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• v.47 no.2
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• pp.204-211
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• 2015

Probabilistic safety assessment (PSA) has had a significant role in quantitative decision-making by finding design and operational vulnerabilities and evaluating cost-benefit in improving such weak points. In particular, it has been widely used as the core methodology for risk-informed applications (RIAs). Even though the nature of PSA seeks realistic results, there are still "conservative" aspects. One of the sources for the conservatism is the assumptions of safety analysis and the estimation of failure frequency. Surveillance, diagnosis, and prognosis (SDP), utilizing massive databases and information technology, is worth highlighting in terms of its capability for alleviating the conservatism in conventional PSA. This article provides enabling techniques to solidify a method to provide time- and condition-dependent risks by integrating a conventional PSA model with condition monitoring and prognostics techniques. We will discuss how to integrate the results with frequency of initiating events (IEs) and probability of basic events (BEs). Two illustrative examples will be introduced: (1) how the failure probability of a passive system can be evaluated under different plant conditions and (2) how the IE frequency for a steam generator tube rupture (SGTR) can be updated in terms of operating time. We expect that the proposed model can take a role of annunciator to show the variation of core damage frequency (CDF) depending on operational conditions.

• The Journal of Korean Association of Computer Education
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• v.14 no.4
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• pp.33-41
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• 2011

This study was conducted to identify factors that influenced teachers' adoption of digital textbooks and causal relationships among the factors identified. Chasm theory was used in developing strategies for adoption of digital textbooks that consider teachers' innovativeness. This study also employed the information technology adoption model of Davis (1989) that illustrates decision making processes for the adoption of instructional media such as digital textbooks. Based on these two theories, a measurement instrument measuring teachers' innovativeness, perceived usefulness, perceived ease of use, and intention of use was developed and validated through a series of reliability and validity tests. Causal relationships among the factors were examined using structural equation modeling. The result indicated that: a) perceived ease of use had a directional effect on perceived usefulness and an indirect effect on intention of use; and b) perceived usefulness had a direct effect on intention of use. Implications of this finding are discussed especially for the efforts in developing strategies for teachers' adoption of digital textbook. For example, when digital textbooks are introduced into public schools, teachers' perception of the usefulness of digital textbooks, beyond just ease of use, should be considered.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.936-942
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• 2015

This paper suggests the significant strategies and their priority to deal with space transportation market trends. First, market trends related with technical improvement and change in demand are analyzed by the literature research. The three key trends are obtained: 'Increasing Demand of High-Performance Launch Vehicles', 'Rising of Low-Price Launch Vehicles', and 'Rising of Dual/Multi-Launch'. And then, strategies for developing the launch vehicle industry in Korea are selected from several studies about commercialization of Korean launch vehicle. The strategies are evaluated by the experts through pairwise comparison matrix and the criteria for this process is how significantly does the strategy effect on the launch vehicle industry through market assessment. As a result, reliable order of priority among the strategies are obtained. Under the three key trends, strategy to enhance reliability is most important. And, strategy to have price competitiveness has secondary priority to deal with 'Rising of Low-Price Launch Vehicles' trend and 'Rising of Dual/Multi-Launch' trend. On the contrary, strategy of government's support is secondary under 'Increasing Demand of High-Performance Launch Vehicles' trend.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.71-79
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• 2007

It is common that the analysis of VE/LCC is performed in design phase of quay wall structures. The analysis is mainly executed based on experience and engineering sense of expert considering the selection of construction method, construction and maintenance cost. Recently there are increasing demands on the analysis that includes uncertainty and vulnerability of input parameters, for this purpose, fuzzy reliability based probabilistic VE/LCC analysis model for quay wall structures is suggested. In VE/LCC analysis for quay wall structures, the application of probabilistic analysis method give very similar results compare with those of deterministic analysis method. It is anticipated that the methodology proposed in this paper can also be utilized in the design and maintenance phase of other facilities where decision making is made for the probabilistic life cycle cost and value analysis.

• 기술발표회
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• s.2006
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• pp.279-291
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• 2006

This study shows decision-making process for selection of cutoff wall on a wastewater treatment project. There are 10 different cut-off wall methods So, we examine the site to gather information for find appropriate methods. After using that information, 10 cutoff wall methods are reviewed for analysis. Through brainstorming, four alternatives are selected for design VE item. Following the standard VE process, we established performance criteria and evaluated function score(F) using questionnaire. The questionnaires, brainstorming and AHP method for weighting on performance criteria and evaluate function score increased the reliability of this selection process. Water Jet method, one of four methods, has the best function score(F=92.71) and the lease construction cost(as cost index 1,000). The value score also highest as 92.7, so we select the method. The result is value innovation type In addition, the authors try to calculate the environmental burden in selection process using LCA. We cannot conduct the full LCA as defined ISO, so perform Simple LCA In LCA result, the cut-off grouting has the least environmental burden as index 9.09E+01 and Water Jet method has following as the second. To selection best method to specific area and purpose, design VE/LCG process used as useful tool and it is needed to develop integrated method that evaluate VEILCC and LCA as one-set process.

• Smart Structures and Systems
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• v.6 no.9
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• pp.1057-1077
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• 2010

An early detection of structural damages is critical for the decision making of repair and replacement maintenance in order to guarantee a specified structural reliability. Consequently, the structural damage detection, based on vibration data measured from the structural health monitoring (SHM) system, has received considerable attention recently. The traditional time-domain analysis techniques, such as the least square estimation (LSE) method and the extended Kalman filter (EKF) approach, require that all the external excitations (inputs) be available, which may not be the case for some SHM systems. Recently, these two approaches have been extended to cover the general case where some of the external excitations (inputs) are not measured, referred to as the adaptive LSE with unknown inputs (ALSE-UI) and the adaptive EKF with unknown inputs (AEKF-UI). Also, new analysis methods, referred to as the adaptive sequential non-linear least-square estimation with unknown inputs and unknown outputs (ASNLSE-UI-UO) and the adaptive quadratic sum-squares error with unknown inputs (AQSSE-UI), have been proposed for the damage tracking of structures when some of the acceleration responses are not measured and the external excitations are not available. In this paper, these newly proposed analysis methods will be compared in terms of accuracy, convergence and efficiency, for damage identification of structures based on experimental data obtained through a series of laboratory tests using a scaled 3-story building model with white noise excitations. The capability of the ALSE-UI, AEKF-UI, ASNLSE-UI-UO and AQSSE-UI approaches in tracking the structural damages will be demonstrated and compared.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.123-135
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• 2007

In the recent years, the companies have manually recorded a production status in a work diary or have mainly used a bar code in order to collect each process's progress status, production performance and quality information in the production and logistics process in real time. But, it requires an additional work because the worker's record must be daily checked or the worker must read it with the bar code scanner. At this time, data's accuracy is decreased owing to the worker's intention or mistake, and it causes the problem of the system's reliability. Accordingly, in order to solve such problem, the companies have introduced RFID which comes into the spotlight in the latest automatic identification field. In order to introduce the RFID technology, the process flow must be analyzed, but the ASME sign used by most manufacturing companies has the difficult problem when the aggregation event occurs. Hence, in this study, the RFID logistic flow analysis Modeling Notation was proposed as the signature which can analyze the manufacturing logistic flow amicably, and the manufacturing logistic flow by industry type was analyzed by using the proposed RFID logistic flow analysis signature. Also, to monitor real-time information through EPCglobal network, EPCISEvent template by industry was proposed, and it was utilized as the benchmarking case of companies for RFID introduction. This study suggested to ensure the decision-making on real-time information through EPCglobal network. This study is intended to suggest the Modeling Notation suitable for RFID characteristics, and the study is intended to establish the business step and to present the vocabulary.