• Title/Summary/Keyword: computer models

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Improved Statistical Grey-Level Models for PCB Inspection (PCB 검사를 위한 개선된 통계적 그레이레벨 모델)

  • Bok, Jin Seop;Cho, Tai-Hoon
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.1
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    • pp.1-7
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    • 2013
  • Grey-level statistical models have been widely used in many applications for object location and identification. However, conventional models yield some problems in model refinement when training images are not properly aligned, and have difficulties for real-time recognition of arbitrarily rotated models. This paper presents improved grey-level statistical models that align training images using image or feature matching to overcome problems in model refinement of conventional models, and that enable real-time recognition of arbitrarily rotated objects using efficient hierarchical search methods. Edges or features extracted from a mean training image are used for accurate alignment of models in the search image. On the aligned position and orientation, fitness measure based on grey-level statistical models is computed for object recognition. It is demonstrated in various experiments in PCB inspection that proposed methods are superior to conventional methods in recognition accuracy and speed.

MIXED INTEGER PROGRAMMING MODELS FOR DISPATCHING VEHICLES AT A CONTAINER TERMINAL

  • ZHANG LI WEI;YE RONG;HUANG SHELL YING;HSU WEN JING
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.145-170
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    • 2005
  • This paper presents scheduling models for dispatching vehicles to accomplish a sequence of container jobs at the container terminal, in which the starting times as well as the order of vehicles for carrying out these jobs need to be determined. To deal with this scheduling problem, three mixed 0-1 integer programming models, Model 1, Model 2 and Model 3 are provided. We present interesting techniques to reformulate the two mixed integer programming models, Model 1 and Model 2, as pure 0-1 integer programming problems with simple constraint sets and present a lower bound for the optimal value of Model 1. Model 3 is a complicated mixed integer programming model because it involves a set of non-smooth constraints, but it can be proved that its solutions may be obtained by the so-called greedy algorithm. We present numerical results showing that Model 3 is the best among these three models and the greedy algorithm is capable of solving large scale problems.

Computer Models on Oxygenation Process in the Pulmonary Circulation by Gas Diffusion

  • Chang, Keun-Shik;Bae, Hwang
    • International Journal of Vascular Biomedical Engineering
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    • v.4 no.1
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    • pp.9-16
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    • 2006
  • In this article we introduce computer models that have been developed in the past to determine the concentration of metabolic gases, the oxygen and carbon dioxide, along the pulmonary circulation. The terminal concentration of these gases in the arterial blood is related with the total change of the partial pressure of the same gases in the alveoli for the time beginning with inspiration and ending with expiration. It is affected not only by the ventilation-perfusion ratio and the gas diffusion capacity of the lung membrane but also by the pulmonary defect such as shunt, dead space, diffusion impairment and ventilation-perfusion mismatch. Some pathological pulmonary symptoms such as ARDS and CDPD can be understood through the mathematical models of these pulmonary dysfunctions. Quantitative study on the blood oxygenation process using various computer models is therefore of foremost importance in order to monitor not only the pulmonary health but also the cardiac output and cell metabolism. Reviewed in this paper include the basic and advanced methods that enable numerical study on the gas exchange and on the arterial oxygenation process, which might depend on the various heart and lung physiological conditions listed above.

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Feature Analysis for Detecting Mobile Application Review Generated by AI-Based Language Model

  • Lee, Seung-Cheol;Jang, Yonghun;Park, Chang-Hyeon;Seo, Yeong-Seok
    • Journal of Information Processing Systems
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    • v.18 no.5
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    • pp.650-664
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    • 2022
  • Mobile applications can be easily downloaded and installed via markets. However, malware and malicious applications containing unwanted advertisements exist in these application markets. Therefore, smartphone users install applications with reference to the application review to avoid such malicious applications. An application review typically comprises contents for evaluation; however, a false review with a specific purpose can be included. Such false reviews are known as fake reviews, and they can be generated using artificial intelligence (AI)-based text-generating models. Recently, AI-based text-generating models have been developed rapidly and demonstrate high-quality generated texts. Herein, we analyze the features of fake reviews generated from Generative Pre-Training-2 (GPT-2), an AI-based text-generating model and create a model to detect those fake reviews. First, we collect a real human-written application review from Kaggle. Subsequently, we identify features of the fake review using natural language processing and statistical analysis. Next, we generate fake review detection models using five types of machine-learning models trained using identified features. In terms of the performances of the fake review detection models, we achieved average F1-scores of 0.738, 0.723, and 0.730 for the fake review, real review, and overall classifications, respectively.

A Study on Presentation Methods for Formation Ideas of Interior Spaces (실내 공간 형상화를 위한 아이디어 표현 방법에 관한 연구)

  • Lee, Jong-Ran
    • Journal of The Korean Digital Architecture Interior Association
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    • v.6 no.2
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    • pp.17-23
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    • 2006
  • The purpose of this study was to investigate how student felt the strengths and shortness of presentation methods for formation of interior spaces. For this study, the process of the interior architecture design class was divided into three stages: the programming. the design development, and the design completion. In the design development stage, students used presentation methods: hand sketch, scale model, computer modeling, and virtual realty. The strengths of hand sketch was that quick expression. Models provided three-dimensional feelings. Computer modelling provide realistic color and texture. Virtual reality provided three-dimensional immersion and real scale. It is effective that students collect brain storm images using quick hand sketch in the beginning of design development stage. After that, they compose interior spaces in study models with small scale. Watching the models, they design details of spaces by using hand sketch and computer modelling. Using virtual reality, they can check the scale and circulation. Finally, they complete computer modelling by texture mapping and check the final design in virtual reality.

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Latest Transformations of XP Process Model: A Systematic Literature Review

  • Khan, Sadia;Fahiem, Muhammad Abuzar;Bakhtawar, Birra;Aftab, Shabib;Ahmad, Munir;Aziz, Nauman;Almotilag, Abdullah;Elmitwally, Nouh Sabri
    • International Journal of Computer Science & Network Security
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    • v.21 no.6
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    • pp.143-150
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    • 2021
  • Process model is an integral part of software industry. Different process models are used now a days in the industry for different software projects. Process models need to be tailored to address some specific project needs. Agile models are considered as the most widely used process models nowadays. They have distinctive features and the ability to address the dynamic needs of today's software development. Extreme programming (XP) is one of the extensively used agile process model especially for small projects. Many researchers have tried to mold XP to overcome its shortcomings and for better working in specific scenarios. Therefore, many customized versions of XP process model are available today. In this paper, we are going to analyze the latest customizations of XP. For this purpose, a systematic literature review is conducted on studies published from 2012 till 2018 in renowned online search libraries. This comprehensive review highlights the purpose of customizations, along with the areas in which customizations are made, and phases & practices which are being customized. This work will serve the researchers to discover the modern versions of XP process model as well as will provide a baseline for future directions for customizations.

Performance Comparison of Commercial and Customized CNN for Detection in Nodular Lung Cancer (결절성 폐암 검출을 위한 상용 및 맞춤형 CNN의 성능 비교)

  • Park, Sung-Wook;Kim, Seunghyun;Lim, Su-Chang;Kim, Do-Yeon
    • Journal of Korea Multimedia Society
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    • v.23 no.6
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    • pp.729-737
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    • 2020
  • Screening with low-dose spiral computed tomography (LDCT) has been shown to reduce lung cancer mortality by about 20% when compared to standard chest radiography. One of the problems arising from screening programs is that large amounts of CT image data must be interpreted by radiologists. To solve this problem, automated detection of pulmonary nodules is necessary; however, this is a challenging task because of the high number of false positive results. Here we demonstrate detection of pulmonary nodules using six off-the-shelf convolutional neural network (CNN) models after modification of the input/output layers and end-to-end training based on publicly databases for comparative evaluation. We used the well-known CNN models, LeNet-5, VGG-16, GoogLeNet Inception V3, ResNet-152, DensNet-201, and NASNet. Most of the CNN models provided superior results to those of obtained using customized CNN models. It is more desirable to modify the proven off-the-shelf network model than to customize the network model to detect the pulmonary nodules.

Neural computer systems (뇌세포형 컴퓨터 시스템)

  • 김성수;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.552-555
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    • 1988
  • In this paper, the authors introduce the concepts of neural computer systems which have been studied over 25 years in other countries. And also we illustrate the models of neural networks suggested by researchers. Our fundamental hypothesis is that these models are applicable to the construction of artificial neural systems including neural computers. Therefore we assume that neural computer systems are abstract computer systems based on the computational properties of human brains and particularly well suited for problems in vision and language understanding.

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Models for Internet Traffic Sharing in Computer Network

  • Alrusaini, Othman A.;Shafie, Emad A.;Elgabbani, Badreldin O.S.
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.28-34
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    • 2021
  • Internet Service Providers (ISPs) constantly endeavor to resolve network congestion, in order to provide fast and cheap services to the customers. This study suggests two models based on Markov chain, using three and four access attempts to complete the call. It involves a comparative study of four models to check the relationship between Internet Access sharing traffic, and the possibility of network jamming. The first model is a Markov chain, based on call-by-call attempt, whereas the second is based on two attempts. Models III&IV suggested by the authors are based on the assumption of three and four attempts. The assessment reveals that sometimes by increasing the number of attempts for the same operator, the chances for the customers to complete the call, is also increased due to blocking probabilities. Three and four attempts express the actual relationship between traffic sharing and blocking probability based on Markov using MATLAB tools with initial probability values. The study reflects shouting results compared to I&II models using one and two attempts. The success ratio of the first model is 84.5%, and that of the second is 90.6% to complete the call, whereas models using three and four attempts have 94.95% and 95.12% respectively to complete the call.

An Experimental Dosimetry of Irregularly Shaped Fields Using Therapeutic Planning Computer (치료계획용 컴퓨터를 이용한 부정형조사면의 선량분포에 관한 실험)

  • Kwon Hyoung Cheol;Oh Yoon Kyeong;Yoon Sei Chul;Bahk Young Whee
    • Radiation Oncology Journal
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    • v.2 no.2
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    • pp.281-285
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    • 1984
  • The authors have intended to measure intrinsic dose distribution by Farmer dosimeter in irregularly shaped fields such as L.M and T shape models in order to determine dose inhomogeneity in those models. We made 2 off·axis points in each model and measured the depth dose at 1.5, 5 and 9cm below surface. The results showed $l\~3\%$ dose discrepancy between 2 points. We also measured the depth dose by geometric approximation and computer calculation in those models, and came to the conclusion that computer calculation using Clarkson's principle is simpler and the measurements are closer to the ideal data obtained by the experiment in three models of irregularly shaped fields than those of geometric approximation method.

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