• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.455-462
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• 2020

Noise which is unwanted sound is a serious pollutant that can affect human health, as well as the working and living environment if exposed to humans. However, current noise management on the construction project is generally conducted after the noise exceeds the regulation standard, which increases the conflicts with inhabitants near the construction site and threats to the safety and productivity of construction workers. To overcome the limitations of the current noise management methods, the activities of construction equipment which is the main source of construction noise need to be managed throughout the construction period in real-time. Therefore, this paper proposed a framework for automatically detecting noise sources in construction sites in real-time based on convolutional neural networks (CNNs) according to the following four steps: (i) Step 1: Definition of the noise sources; (ii) Step 2: Data preparation; (iii) Step 3: Noise source classification using the audio CNN; and (iv) Step 4: Noise source detection using the visual CNN. The short-time Fourier transform (STFT) and temporal image processing are used to contain temporal features of the audio and visual data. In addition, the AlexNet and You Only Look Once v3 (YOLOv3) algorithms have been adopted to classify and detect the noise sources in real-time. As a result, the proposed framework is expected to immediately find construction activities as current noise sources on the video of the construction site. The proposed framework could be helpful for environmental construction managers to efficiently identify and control the noise by automatically detecting the noise sources among many activities carried out by various types of construction equipment. Thereby, not only conflicts between inhabitants and construction companies caused by construction noise can be prevented, but also the noise-related health risks and productivity degradation for construction workers and inhabitants near the construction site can be minimized.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권1호
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• pp.22-29
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• 2007

Two fuzzy controllers defined by 2 input variables cooperate to control a cartpole system in terms of balancing as well as centering. The cooperation is due to the BOXES scheme that selects one of the fuzzy controllers for each time step according to the content of box that is established through the critic of the control action by the fuzzy controllers. It is found that the control scheme is good at controlling the cartpole system so that the system is stabilized fast while the BOXES develops its ability to select proper fuzzy controller through experience.

• 대한기계학회논문집
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• 제15권2호
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• pp.436-444
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• 1991

A computational method has been developed to analyze the bone-remodeling induced by external fixator. The method was based on the Finite Element Method (FEM) in combination with numerical formulation of adaptive bone-remodeling theories. As a feed-back control variable, compressive strain and effective stress were used to determine the surface remodeling and internal (density) remodeling respectively. Surface remodeling and internal remodeling were combined at each time step to predict the rel situation. A noticeable shape and density change were detected at the region between two pins and density change was decreased with time increment. At final time step, the shape and density distribution were converged closely to its original intact bone model. Similar change was detected in stress distribution. The altered stress distribution due to the pin and external fixator converged to the intact stress distribution with time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.696-698
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• 1997

The marine diesel engine have been widely applied with a mechanical hydraulic governor to control the ship speed for long time. But it was recently very difficult for the mechanical hydraulic governor to control the speed of engine under the condition of low speed and low load because of jiggling by rough fluctuation of rotating torque and hunting by dead time of diesel engine. In order to analyze the speed control system the transfer function was converted from z to w transformation. The author proposed velocity control system with feedback loop by PID controller in order to stabilize for unstable area. The influence of dead time was discussed by Nichols chart and unit step response curve. It was confirmed through computer simulation that the performance improvement of a mechanical hydraulic governor can be obtained by PID controller.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.538-541
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• 2005

Most realistic control systems contain nonlinearities of some form. One nonlinearity commonly found in control systems is a saturating element. If integral control is applied to such a system to eliminate steady state error, an undesired side effect known as integrator windup may occur when lage setpoint changes are made. This effect leads to a characteristic step response with a large overshoot and a very high settling time. To avoid this situation, many different anti-windup strategies have been suggested. But existing strategies remain over shoot and high settling time. This paper proposes a new anti-windup strategy for PI speed controllers. When the speed control system is changed P controller to PI controller. Integrator has an appropriate initial value. This value results over shoot and high settling time. The SIMULINK/MATLAB-based comparative simulation results and experiment results of speed controller have shown its superior control performance to that of a proposed anti-windup speed controller.

• 문화기술의 융합
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• 제10권4호
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• pp.235-240
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• 2024

건강한 노년을 위해 중년부터 건강 관리를 해나가야 한다. 본 연구의 목적은 중년여성들이 시간과 장소에 구애 받지 않고 간단한 운동을 통해 최대 효과를 볼 수 있는 운동 프로그램을 적용하여 보행메커니즘에 미치는 영향을 확인하고자 시행되었다. 연구대상자는 45세 이상 중년 여성을 대상으로 종아리 강화 운동 그룹 10명, 대조군 10명으로 총 20명을 선정하였다. 종아리 강화 운동군의 운동 전후를 비교한 결과 step length 좌측과 우측 그리고 double support, step time(좌), speed가 향상되었다. 운동 후 종아리 강화 운동군과 비운동 그룹의 보행메커니즘을 비교한 결과 step length 좌측과 우측, step time 좌측과 우측이 향상되었다. 시간 및 장소에 특별히 구애 받지 않는 종아리 강화 운동을 통해 보행메커니즘의 긍정적 효과를 보였다. 특히 보폭은 넓어져 하지의 힘이 생기고 한발 지지구간은 짧아져 보행의 속도는 증가한 것으로 나타나 의미 있는 결과를 도출했다고 판단한다. 향후 연구에서는 청소년, 노년 층 등 전 연령에 걸쳐 평가하여 생애주기 별 측정데이터를 제시하고 평상시 운동 부족으로 사회적 문제를 야기하는데 있어 기초자료로 제공하는 것이 바람직할 것으로 사료된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.140-145
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• 1994

In this paper, we consider a problem to estimate process parameters using input-output data collected from the process operating in closed-loop control system. When orders and delay-time of the process are known correctly, under some conditions of identifying experiments, it is reported that accurate identification results can be obtained by applying prediction error method. To get accurate estimates, it is necessary to know orders and delay-time of the process. It is difficult to determine them in closed-loop identification, because ill-condition for identification are easily caused by selection of unsuitable order or delay time. Furthermore, the procedures to select orders and delay-time in open-loop identification aren't always available in closed-loop identification. The purpose of this paper is to determine a delay-time under suitable assumption that order of the process are known as the first step.

• 아태비즈니스연구
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• 제14권1호
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• pp.313-325
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• 2023

Purpose - The purpose of this study is to examine the process of determining control in a situation where investors hold less than a majority of the voting rights of the investee through case. Design/methodology/approach - In this study, the various and complex considerations presented in K-IFRS 1110 'Consolidated Financial Statements' were systematically classified and stratified. Findings - First, the agreement to delegate voting rights does not necessarily have to be documented, but it can be said to be substantive rights right only if it is not of the nature that one party can discontinue at any time. Second, if it is clear that investors do not have power due to the relative size of voting rights and the degree of stock dispersion, there is no need to review the past shareholders' meeting resolutions and additional facts and circumstances. Research implications or Originality - This study expects to minimize errors in applying the standards by classifying and stratifying the various considerations presented in K-IFRS 1110 into first and subsequent considerations. In addition, it is expected to contribute to reducing practical confusion in determining control by presenting a step-by-step review through case on whether or not to have power to judge control when holding voting rights of less than a majority.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.191-192
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• 2017

본 6-스텝 운전은 하드웨어의 수정 없이 운전 영역을 확장할 수 있다는 장점을 가진다. 하지만, 샘플링 주파수 대비 기본파 주파수가 크면 저주파수 전류 맥동 문제가 발생한다. 이는 시스템의 효율을 낮추고 안정성 문제를 일으킨다. 따라서, 본 논문에서는 가변 시간 제어 방법을 제안한다. 선형화과정을 통해 정확한 전달 함수를 구하고, 이를 이용하여 추가적인 약 자속 제어기나 전류 지령 생성기 없이 6-스텝 운전을 구현 할 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.163.3-163
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• 2001

This paper presents the two-step strategy method of performing optimal scheduling of paper mill processes using MINLP (Mixed-Integer Non-Linear Programming) considering the trim loss problem in sheet cutting processes. The mathematical model for a sheet cutting process in the form of MINLP is developed in this study, and minimizing total cost is performed considering the cost of raw paper roll, :hanging cutting patterns, storage of over-product and recycling/burning trim. The paper has been used to deliver and conserve information for a long time, and it is needed to have various sizes and weights ...