• Title, Summary, Keyword: models

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Survey of Visual Search Performance Models to Evaluate Accuracy and Speed of Visual Search Tasks

  • Kee, Dohyung
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.3
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    • pp.255-265
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    • 2017
  • Objective: This study aims to survey visual search performance models to assess and predict individual's visual tasks in everyday life and industrial sites. Background: Visual search is one of the most frequently performed and critical activities in everyday life and works. Visual search performance models are needed when designing or assessing the visual tasks. Method: This study was mainly based on survey of literatures related to ergonomics relevant journals and web surfing. In the survey, the keywords of visual search, visual search performance, visual search model, etc. were used. Results: On the basis of the purposes, developing methods and results of the models, this study categorized visual search performance models into six groups: probability-based models, SATO models, visual lobe-based models, computer vision models, neutral network-based models and detection time models. Major models by the categories were presented with their advantages and disadvantages. More models adopted the accuracy among two factors of accuracy and speed characterizing visual tasks as dependent variables. Conclusion: This study reviewed and summarized various visual search performance models. Application: The results would be used as a reference or tool when assessing the visual tasks.

A Comparison of Seasonal Linear Models and Seasonal ARIMA Models for Forecasting Intra-Day Call Arrivals

  • Kim, Myung-Suk
    • Communications for Statistical Applications and Methods
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    • v.18 no.2
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    • pp.237-244
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    • 2011
  • In call forecasting literature, both the seasonal autoregressive integrated moving average(ARIMA) type models and seasonal linear models have been popularly suggested as competing models. However, their parallel comparison for the forecasting accuracy was not strictly investigated before. This study evaluates the accuracy of both the seasonal linear models and the seasonal ARIMA-type models when predicting intra-day call arrival rates using both real and simulated data. The seasonal linear models outperform the seasonal ARIMA-type models in both one-day-ahead and one-week-ahead call forecasting in our empirical study.

Voting and Ensemble Schemes Based on CNN Models for Photo-Based Gender Prediction

  • Jhang, Kyoungson
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.809-819
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    • 2020
  • Gender prediction accuracy increases as convolutional neural network (CNN) architecture evolves. This paper compares voting and ensemble schemes to utilize the already trained five CNN models to further improve gender prediction accuracy. The majority voting usually requires odd-numbered models while the proposed softmax-based voting can utilize any number of models to improve accuracy. The ensemble of CNN models combined with one more fully-connected layer requires further tuning or training of the models combined. With experiments, it is observed that the voting or ensemble of CNN models leads to further improvement of gender prediction accuracy and that especially softmax-based voters always show better gender prediction accuracy than majority voters. Also, compared with softmax-based voters, ensemble models show a slightly better or similar accuracy with added training of the combined CNN models. Softmax-based voting can be a fast and efficient way to get better accuracy without further training since the selection of the top accuracy models among available CNN pre-trained models usually leads to similar accuracy to that of the corresponding ensemble models.

An Evaluation Models for R&D Projects Selection (연구개발과제 선정을 위한 단계별 평가모형)

  • 이상철;하정진;김성희
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.17 no.31
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    • pp.73-80
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    • 1994
  • Sequentiality in decision making is an inherent characteristic of the R&D Process, Conceptual changes are noted during the Course of the Project which represent a continuous improvement in the quality of the data available during the various project stages. In this paper, Eight characteristic types of project evaluation models have been developed economic index models, portfolio models, decision theory models, risk analysis models, frontier models, scoring models, profile models and checklists. Each of these will be critically reviewed and appraised.

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A Study on Adoption/Diffusion Models for New Product (신제품 수용$\cdot$확산모형에 관한 연구)

  • 김용준;박영근
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.10 no.16
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    • pp.149-158
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    • 1987
  • The Adoption/Diffusion of Innovations(New Product), a topic of study and research that has frown rapidly in the past few decades, deals with how a new product is adopted in a society. It is of high importance to marketing organizations because New Products must be brought out continuously in order to service. The purpose of this paper is to examine the Adoption/Diffusion Models for New product which will help to analyze the Adoption/Diffusion process of Adopters. There are a number of models that, with varying degrees of success, have been used to predict market acceptance of new product. In this paper, following types of new product Adoption/Diffusion Models was suggested. (1) Adoption Models : The Alternative Models of Adoption. The Rogers Model of the Innovation Decision Process. (2) Diffusion Models : First Purchase Models(Basic Models, Extension of the Basic Models), Repeat Purchase Models

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Preservice Elementary Teachers' Perceptions on Models Used in Science and Science Education (과학과 과학 교육에서 사용되는 모델에 관한 예비 초등 교사들의 인식)

  • Oh, Phil-Seok
    • Journal of Korean Elementary Science Education
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    • v.28 no.4
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    • pp.450-466
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    • 2009
  • The purpose of this study was to explore preservice elementary teachers' perceptions on models used in science and science education. Participants were sixty-one undergraduate students who were enrolled in a science education course offered at a university of education located in a mid-sized city, Korea. Data were obtained from the participants at the beginning of the course when they provided their answers to a questionnaire about models. The analysis revealed that a large number of the preservice teachers perceived models as representative of physical realities. By contrast, a relatively small number of them viewed models as representations of ideas or things like theories or hypotheses. Lots of the participants were apt to define a model from the perspective of its functions and considered the purposes of models communication, teaching, and understanding as well as visualization, simplification, and clarification. Most of the preservice teachers believed that there could be multiple models for a single target, and all of them answered that models could be changed in science. It was therefore concluded that the preservice teachers perceived properly the multiplicity and variability of models. Nevertheless, they could not elaborate how a model is used and evaluated in the process of scientific inquiry, and just a few of them mentioned the detailed nature of models. The preservice teachers possessed teacher-centered views of using models in the science classroom, and a small number of them remarked that they were going to use models for students to develop their own models and perform scientific inquiry.

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Accuracy of Bolton analysis measured in laser scanned digital models compared with plaster models (gold standard) and cone-beam computer tomography images

  • Kim, Jooseong;Lagravere, Manuel O.
    • The korean journal of orthodontics
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    • v.46 no.1
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    • pp.13-19
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    • 2016
  • Objective: The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models. Methods: CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC). Results: Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were $0.41{\pm}0.305%$ and $0.45{\pm}0.456%$, respectively; for anterior Bolton ratios, $0.59{\pm}0.520%$ and $1.01{\pm}0.780%$, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis. Conclusions: Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis.

Validity on the Study Models of Dental Simulation Training: Focus on the Dental Arch and Occlusal Curvature

  • Lee, Hee-Kyung;Nam, Shin-Eun
    • International Journal of Clinical Preventive Dentistry
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    • v.14 no.3
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    • pp.171-176
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    • 2018
  • Objective: The purpose of this study was to evaluate the validity of the study models involved in the simulation training for dental technology using 3-dimensional virtual models. Methods: The study models and dental models from 25 young adult Korean were scanned as a virtual dental model with a 3-dimensional scanner (Scanner S600; Zirkonzahn). The dental arch form (arch width, arch length), buccolingual cusp inclination, and the radius of Monson's sphere were measured on prepared virtual models using RapidForm2004 (INUS Technology Inc.). Wilcoxon signed-rank test was performed to verify the validity of the study models participating in the dental technique training using 3-dimensional virtual models (${\alpha}=0.05$). Results: Arch width (intercanine width/intermolar width) and arch length (incisor to intercanine/incisor to intermolar) were smaller in both upper and lower study models than those of adult Korean models in general (p<0.05). In maxilla, buccolingual cusp inclinations of right and left side of premolars and molar were larger ($2.21^{\circ}-5.20^{\circ}$) in adult Korean models except for the first molar (p<0.05), which was the opposite in mandible ($2.98^{\circ}-9.20^{\circ}$) (p<0.05). The radii of Monson' sphere was 104.92 mm in the study models and $121.85{\pm}47.11mm$ in adult Korean models. There was no statistically significant difference between the two groups (p>0.05). Conclusion: In the study models involved in the simulation training, dental arch was smaller. Buccolingual cusp inclination was more inclined for upper and less inclined for lower than 25 subjects. This finding could be used as a meaningful reference for further studies focusing on validity on dental technique trainings for study models.

The development of Governor models for implementation into EMTDC and the verification of Governor models using GSTEP (EMTDC용 조속기 모델 개발 및 GSTEP을 이용한 검증)

  • Hur, J.;Kim, D.J.;Yoon, J.Y.;Moon, Y.H.;Lee, J.;Yoon, Y.B.
    • Proceedings of the KIEE Conference
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    • pp.71-74
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    • 2001
  • In general, the PSS/E program based on RMS mathematical models is used for analyzing the steady state and transient stability phenomena of full-scale large power system. Whereas, the EMTDC program unlike PSS/E, studies the specific reduced small-scale power systems as a basis of instantaneous value mathematical models and used to analyze the Electro-Magnetic transient characteristics. The PSS/E provides various control models such as exciter, governor and PSS models, But there are few control models in EMTDC. In this paper, we developed EMTDC models for governor which have been applied in KEPCO system. The EMTDC models are developed by examining PSS/E control block and using User Define Model in addition to default.lib provided by EMTDC. we verify the correctness of developed governor models with PSS/E and EMTDC simulation results using Governor Step(GSTEP) method.

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Seismic Analysis Models for Typical Roadway Bridges considering failure Mechanisms (파괴메카니즘을 고려한 일반도로교의 지진해석모델)

  • 국승규;김판배
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.295-301
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    • 2001
  • For the seismic analysis of typical roadway bridges provisions are given in most codes for analysis models, which describes however only fundamental modelling methods according to the basic theories of structural dynamics. In practice even conventional non-seismic analysis models, separate super- and substructure models, are applied, which are not adequate because of neglecting connection elements. In this study three typical roadway bridges, a Steel box bridge, a PC beam bridge and a PC box bridge are selected and simple models integrating super- and substructure as well as connection elements are given. The simple models are composed with frame elements with lumped masses representing stiffness and mass characteristics of the selected bridges. To check the properness of the simple models, analysis results with the simple models are compared with those obtained with detailed models in view of bridge failure mechanisms. It is proved that the simple models can be used in the preliminary design phase fur the determination of failure mechanisms of typical roadway bridges.

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