• Title/Summary/Keyword: st-convergence

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A Study on Stable Motion Control of Mobile-Manipulators Robot System (모바일-매니퓰레이터 구조 로봇시스템의 안정한 모션제어에 관한연구)

  • Park, Moon-Youl;hwang, Won-Jun;Park, In-Man;Kang, Un-Wook
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.4
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    • pp.217-226
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    • 2014
  • Since the world has changed to a society of 21st century high-tech industries, the modern people have become reluctant to work in a difficult and dirty environment. Therefore, unmanned technologies through robots are being demanded. Now days, effects such as voice, control, obstacle avoidance are being suggested, and especially, voice recognition technique that enables convenient interaction between human and machines is very important. In this study, in order to conduct study on the stable motion control of the robot system that has mobile-manipulator structure and is voice command-based, kinetic interpretation and dynamic modeling of two-armed manipulator and three-wheel mobile robot were conducted. In addition, autonomous driving of three-wheel mobile robot and motion control system of two-armed manipulator were designed, and combined robot control through voice command was conducted. For the performance experiment method, driving control and simulation mock experiment of manipulator that has two-armed structure was conducted, and for experiment of combined robot motion control which is voice command-based, through driving control, motion control of two-armed manipulator, and combined control based on voice command, experiment on stable motion control of voice command-based robot system that has mobile-manipulator structure was verified.

An Auto-tuing of PID Conrtroller using Genetic Algorithms (유전자 알고리즘을 사용한 PID제어기의 자동동조)

  • 이수흠;정순현
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.2
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    • pp.71-75
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    • 2002
  • We propose a new method to deal with the optimized auto-tuning for the PID controller which is used to the process-control in various fields. First of all, in this method, 1st order delay system with dead time which is modelled from the unit step response of the system is Pade-approximated, then initial values are determined by the Ziegler-Nichols method and deciding binary strings of parents generation using by the fitness values of genetic algorithms, we perform selection, crossover and mutation to generate the descendant generation. The advantage of this method is better than the Ziegler-Nickels method in characteristic of output, and has extent of applying without limit of K, L, T parameters.

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Effectiveness of Nutrition Education in Improving Maternal Knowledge and Attitudes towards Complementary Feeding Practices: A cluster-randomized controlled trial in Ondo State, Nigeria

  • Akinrinmade, Remilekun;NJOGU, Eunice;OGADA, Irene Awuor;KESHINRO, Olufunke Oluremi
    • The Korean Journal of Food & Health Convergence
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    • v.5 no.4
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    • pp.1-10
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    • 2019
  • Significant low knowledge and poor attitudes on complementary feeding undermine the practices. This study was a cluster randomized controlled trial in which 284 study participants were assigned into two groups. One intervention group and a control group in a ratio of 1:1. Nutrition education on complementary feeding was carried out among the caregivers in the intervention group but the caregivers in the control group were not educated. To determine complementary feeding knowledge and attitudes, data was collected from caregiver at baseline, midline and at endline using researcher-administered questionnaires. Quantitative data were analyzed using SPSS version 22.0. From the analysis, there was a significant difference in complementary feeding knowledge of the caregivers after the intervention. The baseline difference was -0.06, the midline difference was 3.85 the endline difference was 4.00 and the DID of the baseline and endline was 4.06 which was significant at p=0.001. There was a significant difference in the attitude of the caregivers towards complementary feeding at baseline (-0.14), midline (2.09), endline (3.82) and the DID of baseline and endline was 3.96 which was significant at p=0.001. The intervention improved the caregivers' knowledge on complementary feeding and it improved the attitudes of the caregivers towards adequate complementary feeding.

Case study comparisons of computational fluid dynamics modeling versus tracer test to evaluate the hydraulic efficiency of clearwell (정수지 내 추적자 실험과 CFD(전산유체역학)의 상관관계 분석)

  • Kim, Tae-Kyun;Choi, Young-June;Jo, Young-Mahn
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.5
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    • pp.635-642
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    • 2011
  • Hydraulic efficiency was a vital component in evaluating the disinfection capability of clearwell. Current practice evaluates these system based on the tracer test only. In this paper, CFD(Computational Fluid Dynamics) was applied on the clearwell for alternating or supplementing the tracer test. The baffle factor derived from the CFD modeling closely matched the values obtained from full scale tracer testing. And, for suggesting proper numerical model in clearwell; the turbulence model, discretization scheme, convergence criteria were investigated through separate simulation runs. The model validation was conducted by comparing the simulated data with experimental data. In the turbulence model, the realizable ${\kappa}-{\varepsilon}$ model and the standard ${\kappa}-{\varepsilon}$ model were found to be more appropriate than RNG ${\kappa}-{\varepsilon}$ model. The residuals of convergence criteria should be used as not $10^{-3}$ but $10^{-4}$ or $10^{-5}$. In discretization scheme, the difference of simulated values in 1st, 2nd, 3rd upwind scheme was found to be insignificant. Moreover, the result of this study suggest that CFD modeling can be a reliable alternative to tracer testing for evaluating the hydraulic efficiency.

Disney's Acquisition of Fox and the Changing Media Environment in the U.S. (디즈니의 폭스 인수와 미국의 변화하는 미디어 환경)

  • Joo, Jeong-Suk
    • Journal of Convergence for Information Technology
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    • v.10 no.1
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    • pp.28-34
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    • 2020
  • This paper intends to examine the recent acquisition of 21st Century Fox by Walt Disney Co. in terms of how information communication technology, especially the internet, has been reshaping the media industry. In particular, it looks at the deal as Disney's attempt to adapt to the rapidly shifting media environment and strike back at the challenges from online streaming services. After looking at the overview of the deal and some of the major changes and challenges the rise of streaming services has brought to film and media landscape, the paper looks at Disney responded to them by launching its own streaming services and how its acquisition of Fox assets factors in this. It also examines the implications of Disney's move as well as the opportunity and challenges it faces.

An Analysis of the Importance of the Success Factors in Implementation Stage of ERP System

  • YI, Seon-Gyu;Kim, Jong-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.12
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    • pp.165-171
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    • 2016
  • This study analyzes the relative importance of the introducing factors for the critical success factors in the implementation stage of the lifecycle of ERP system using Delphi technique and Analytic Hierarchy Process(AHP). In the 1st layer of the hierarchy, technical factor is evaluated as the most important factor among organizational, technical, and supplier factors. In the 2nd layer, choosing a proper ERP package is evaluated as the most important factor within 15 factors followed by process-oriented approach, technical suitability, minimized customization, integration and association of system with trading parter, association with legacy systems, and support and involvement of top management. As a result of this analysis enterprise should choose an ERP package that is suitable to its business environment, and make the best use of(take full advantage of) best practice that ERP package provides to optimize the existing business procedure or process(to approach the existing business procedure or process). This study also shows the range of customization of the features provided by the ERP package should be minimized.

Icing Recovery Method Effect on Blood Lactate and Heart Rate after Sports Climbing

  • KIM, Myung Gyun;LEE, Dong Geun;MOON, Hwang Woon
    • Journal of Sport and Applied Science
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    • v.4 no.1
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    • pp.9-14
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    • 2020
  • The purpose of this study is to investigate the effect of ICING recovery method after sports climbing to blood lactate concentration and heart rate. The subjects were 12 male 20s undergraduate students (ICING group of 6, Control group of 6). Blood lactate concentration and heart rate were measured before climbing, after climbing, 5-minute recovery and 10minute recovery. Heart rate were also measured during the climbing. The subjects performed climbing 3 times. Data were analysed by SPSS 20.0. To compare blood lactate concentration and heart rate among groups, the independent samples t-test was employed using an alpha level of .05. Mean and standard deviations were computed. Results show that there is no significant difference between the icing group and non-icing group. Yet, the differences of blood lactate concentration were observed between groups. Blood lactate concentration of icing group was significantly higher than non-icing group in the condition of 1st climbing. Blood lactate concentration of non-icing group was significantly higher than icing group in 2nd 10-minute recovery. ICING recovery method is shown to be not significantly effective to blood lactate concentration and heart rate. This could be comprehended that long-term high-intensity (70% of 1RM) exercise can be prepared for the further research.

Tools for Web-Based Security Management Level Analysis (웹기반 보안 관리 수준 분석 도구)

  • Kim, Jeom-Goo;Choi, Kyong-Ho;Noh, Si-Choon;Lee, Do-Hyeon
    • Convergence Security Journal
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    • v.12 no.3
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    • pp.85-92
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    • 2012
  • Today, the typical web hacking attacks are cross-site scripting(XSS) attacks, injection vulnerabilities, malicious file execution and insecure direct object reference included. Web hacking security systems, access control solutions, access only to the web service and flow inside but do not control the packet. So you have been illegally modified to pass the packet even if the packet is considered as a unnormal packet. The defense system is to fail to appropriate controls. Therefore, in order to ensure a successful web services diagnostic system development is necessary. Web application diagnostic system is real and urgent need and alternative. The diagnostic system development process mu st be carried out step of established diagnostic systems, diagnostic scoping web system vulnerabilities, web application, analysis, security vulnerability assessment and selecting items. And diagnostic system as required by the web system environment using tools, programming languages, interfaces, parameters must be set.

A Study on Preparation Plan against National Industrial Technology Outflow (국가 산업기술유출 대비 방안 연구)

  • Ha, Ok-Hyun
    • Convergence Security Journal
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    • v.9 no.4
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    • pp.55-62
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    • 2009
  • Industrial Security is a management activity protecting industrial asset of enterprise by application of security elements(physical, IP, conversion security tools) and can be understood as a comprehensive term including software aspect(establishment of policy and strategy, maintenance operation, post- response act, etc.) as well as the operation of hardware elements. In this paper, after recognizing the definition and relative concept of industrial security, the role and its relative laws of the industrial security organizations, the management system and the reality, I will find some problems and submit a reform measure. Furthermore I would like to propose the policy direction to enhance the national competitiveness and to become one of the advanced nations in 21st industrial security through the effective industrial security activities of our enterprises.

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Content Based Image Retrieval System using Histogram Intersection and Autocorrelogram (히스토그램 인터섹션과 오토코릴로그램을 이용한 내용기반 영상검색 시스템)

  • 송석진;김효성;이희봉;남기곤
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.1-7
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    • 2002
  • In this paper, when users choose a query image, we implemented a content-based image retrieval system that users can simply choose and extract a object region of query wanted with not only a whole image but various objects in it. Histogram is obtained by improved HSV transformations from query image and then candidate images are retrieved rapidly by a 1st similarity measure with histogram intersection using representative colors of query image. And finally retrieved images are extracted since 2nd similarity measure with banded autocorrelogram is performed so that recall and precision are improved by combining two retrieval methods that can make up for respective weak points. Moreover images in the database are indexed automatically within feature library that makes possible to retrieve images rapidly.

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