• 제목/요약/키워드: empirical modeling

검색결과 965건 처리시간 0.024초

Dynamic wind effects : a comparative study of provisions in codes and standards with wind tunnel data

  • Kijewski, T.;Kareem, A.
    • Wind and Structures
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    • 제1권1호
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    • pp.77-109
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    • 1998
  • An evaluation and comparison of seven of the world's major building codes and standards is conducted in this study, with specific discussion of their estimations of the alongwind, acrosswind, and torsional response, where applicable, for a given building. The codes and standards highlighted by this study are those of the United States, Japan, Australia, the United Kingdom, Canada, China and Europe. In addition, the responses predicted by using the measured power spectra of the alongwind, acrosswind and torsional responses for several building shapes tested in a wind tunnel are presented and a comparison between the response predicted by wind tunnel data and that estimated by some of the standards is conducted. This study serves not only as a comparison of the response estimates by international codes and standards, but also introduces a new set of wind tunnel data for validation of wind tunnel-based empirical expressions.

ON THE STRUCTURAL CHANGE OF THE LEE-CARTER MODEL AND ITS ACTUARIAL APPLICATION

  • Wiratama, Endy Filintas;Kim, So-Yeun;Ko, Bangwon
    • East Asian mathematical journal
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    • 제35권3호
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    • pp.305-318
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    • 2019
  • Over the past decades, the Lee-Carter model [1] has attracted much attention from various demography-related fields in order to project the future mortality rates. In the Lee-Carter model, the speed of mortality improvement is stochastically modeled by the so-called mortality index and is used to forecast the future mortality rates based on the time series analysis. However, the modeling is applied to long time series and thus an important structural change might exist, leading to potentially large long-term forecasting errors. Therefore, in this paper, we are interested in detecting the structural change of the Lee-Carter model and investigating the actuarial implications. For the purpose, we employ the tests proposed by Coelho and Nunes [2] and analyze the mortality data for six countries including Korea since 1970. Also, we calculate life expectancies and whole life insurance premiums by taking into account the structural change found in the Korean male mortality rates. Our empirical result shows that more caution needs to be paid to the Lee-Carter modeling and its actuarial applications.

Three-Dimensional Digital-Mold Modeling and Sand-Printing for Replication of Bronze Mirror

  • Jo, Young Hoon;Lee, Jungmin
    • 보존과학회지
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    • 제37권1호
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    • pp.25-33
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    • 2021
  • To extend the application of digital technology to the replication of artifacts, meticulous details of the process and the diversity of three-dimensional (3D) printing output materials need to be supplemented. Thus, in this study, a bronze mirror with Hwangbichangcheon inscription was digitalized by 3D scanning, converted into a voxel model, and virtual conservation treatment was performed using a haptic device. Furthermore, the digital mold of the bronze mirror completed by Boolean modeling was printed using a 3D sand-printer. Such contactless replication based on digital technology reflects the stability, precision, expressivity, collectivity, durability, and economic feasibility of artifacts. Its application can be further extended to cultural products as well as such areas as education, exhibition, and research. It is expected to be in high demand for metal artifacts that require casting. If empirical studies through experimental research on casting are supplemented in the future, it could extend the application of digital technology-based contactless replication methods.

Analyzing Customer Experience in Hotel Services Using Topic Modeling

  • Nguyen, Van-Ho;Ho, Thanh
    • Journal of Information Processing Systems
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    • 제17권3호
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    • pp.586-598
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    • 2021
  • Nowadays, users' reviews and feedback on e-commerce sites stored in text create a huge source of information for analyzing customers' experience with goods and services provided by a business. In other words, collecting and analyzing this information is necessary to better understand customer needs. In this study, we first collected a corpus with 99,322 customers' comments and opinions in English. From this corpus we chose the best number of topics (K) using Perplexity and Coherence Score measurements as the input parameters for the model. Finally, we conducted an experiment using the latent Dirichlet allocation (LDA) topic model with K coefficients to explore the topic. The model results found hidden topics and keyword sets with high probability that are interesting to users. The application of empirical results from the model will support decision-making to help businesses improve products and services as well as business management and development in the field of hotel services.

Attitude Change Towards Self-Service Technology Adoption Using Latent Growth Modeling

  • Um, Taehyee;Chung, Namho
    • Journal of Smart Tourism
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    • 제2권3호
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    • pp.5-15
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    • 2022
  • As the utilization of technology in the tourism field becomes familiar, it greatly impacts people's tourism activities. These changes could also affect the behavior of tourists during the pandemic. To investigate consumers' adaptation to the self-service technology (SST) environment during the coronavirus disease of 2019 (COVID-19) pandemic, we adopted a model of absorptive capacity as the main framework for empirical research. To track the social effects of COVID-19, consumers' behavioral intentions for four different points in time are collected. The analysis was conducted using latent growth and structural equation modeling. We set the organizational and environmental characteristics as the first step of the model, with assimilation and trust as a middle step. Intention to use a kiosk is placed at the final step as an exploit. Findings indicate that organizational characteristics and environmental characteristics positively influenced assimilation and trust, except for environmental characteristics. Consumers' assimilation in SST encourages immediate intention to use a kiosk. Consumers' trust in kiosks positively impacts both immediate and continuance intention to use a kiosk during COVID-19.

Modeling of the Bainite Transformation kinetics in C-Mn-Mo-Ni Steel weld CGBAZ

  • Uhm, S.;Lee, C.;Kim, J.;Hong, J.
    • International Journal of Korean Welding Society
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    • 제2권1호
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    • pp.11-14
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    • 2002
  • A metallurgical model for bainite transformation kinetics in the coarse-grained heat affected zone(CGHAZ) on the basis of an Avrami-type equation was studied. Isothermal transformation tests were carried out to obtain the empirical equations for incubation time and Avrami kinetic constants for C-Mn-Mo-Ni steel. The effect of prior austenite grain size(PAGS) on the reaction rate of bainite was also investigated. Compared with experimental transformation behavior of bainite, the predicted behavior was in good agreement. It was also found that a smaller grain size retard the bainite reaction rate, contrary to the classical grain size effect and this is considered to be caused by constraint of grain size to bainite growth.

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An Empirical Study on Telemarketing Business(L Insurance Case)

  • Kim, Yon-Hyong;Lee, Seok-Won
    • Journal of the Korean Data and Information Science Society
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    • 제19권3호
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    • pp.877-891
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    • 2008
  • The purpose in this datamining modeling is to maximize the number of L insurance' new customer selected from the S corp.'s customers through the telemarketing. We demonstrated the superiority of this method by comparing the existing marketing method and campaign result. The used software in this analysis is SAS 9.1 and so on.

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The Effects of Fit and Social Construction on Individual Performance

  • Im, Ghi-Young
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2008년도 춘계학술대회
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    • pp.29-34
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    • 2008
  • This study examines the effects of information and communication technologies on individual performance. The literature has paid a considerable amount of attention to social influence as a determinant of individual behavior. We combine task-technology fit with concepts from adaptive structuration theory to specify social influence. In our model, we suggest that individuals should receive support from proper social construction to have additional performance improvement. Empirical data from 317 individuals across 43 teams in 10 companies is used to assess the theoretical model. Our theoretical model received support from the data.

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Mechanistic Pharmacokinetic/pharmacodynamic Modeling in Isolated Perfused Organs and at the Whole-Body Level

  • Weiss, Michael
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.218-219
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    • 2002
  • In the past, the development of pharmacokinetic/pharmacodynamic (PK/PD) models for quantitating the time course of drug responses was mainly based on two types of models, the empirical effect compartment model that simply accounts for the delay between effect and plasma concentration (hysteresis) and the mechanism-based so-called indirect response model. The first approach traces back to a paper by Segre (1) and its application was popularized by Holford and Sheiner (2); indirect response models were introduced by Jusko's group (3). (omitted)

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