• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1062-1073
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• 2004

We describe a looper controller design for a hot strip finishing mill in steel plants. The main function of the looper system is to balance the mass flow of the strip by accumulating material in the middle of the stands. Another function is to control the strip tension which influences the width of the strip. To ensure strip quality, it is very important to control the tension of the hot strip finishing mill. However, because there is a mutual interaction between the looper angle and the strip tension, it is difficult to control the looper system. Previous researches examined only the operation of a single stand. But it is not sufficient to examine the operation and effect of whole stands because the operation is wholly interdependent. In this paper, we present a full model of the hot strip finishing mill in order to more effectively control strip tension. We propose several control methods for the full-stand hot strip finishing mill, denoted as conventional PI, PI with cross gain, and coefficient diagram method (CDM) PID control. In the real plants, there are some problems by using higher order controllers such as LQ, LQG and H$\_$$\infty$/. By comparison, the PID controller is very simple and easy to apply to all real plants. To that end, we present our findings on PID controls and their potential use in the hot strip finishing mill.

• 한국빅데이터학회지
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• 제8권2호
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• pp.125-131
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• 2023

전 세계적으로 약물 부작용은 주요 사망원인의 상위를 차지하고 있다. 약물 부작용에 대해 효과적으로 대응하기 위해, 능동적인 실시간 분석 기반 약물감시 체계로의 전환과 함께 데이터의 표준화와 품질 향상이 필요하다. 이를 위해, 개별 기관의 데이터를 통합하고 대규모 데이터를 활용하여 약물 부작용 예측의 정확도를 높이는 것이 중요하다. 하지만, 각 기관 간의 데이터 공유는 프라이버시 문제를 야기시키고 각기 다른 데이터 표준 구성도 다르다. 본 연구에서는 이 문제를 해결하기 위해, 개인정보보호 법규에 따라 데이터를 직접 공유하지 않고 모델의 학습 결과를 공유하는 연합학습 방식을 채택한다. 각 기관마다 다른 데이터포맷을 Common Data Model(CDM)을 활용하여 데이터 표준화를 수행하고 데이터의 정확성과 일관성을 확립한다. 또한, 클라우드 기반의 연합학습 환경을 구성하여 보안 및 확장 관리에 효율성을 높이는 약물감시 시스템을 제안한다. 이를 통해 기관 간 데이터의 프라이버시를 보호하면서도, 효과적인 의약품 부작용 모니터링과 예측이 가능하다. 약물 부작용으로 인한 사망률 감소와 의료비용 절감을 목표로 하며, 이를 실현하기 위한 다양한 기술적 접근과 방법론을 탐구한다.

• 한국안전학회지
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• 제16권2호
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• pp.57-62
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• 2001

In order to analyze the mechanism of semiconductor device damages by ESD, this paper adopts a new charged-device model(CDM), field-induced charged nudel(FCDM), simulator that is suitable for rapid routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. The high voltage applied to the device under test is raised by the fie]d of non-contacting electrodes in the FCDM simulator. which avoids premature device stressing and permits a faster test cycle. Discharge current md time are measured and calculated The FCDM simulator places the device at a huh voltage without transferring charge to it, by using a non-contacting electrode. The only charge transfer in the FCMD simulator happens during the discharge. This paper examine the field charging mechanism, measure device thresholds, and analyze failure modes. The FCDM simulator provides a Int and inexpensive test that faithfully represents factory ESD hazards. The damaged devices obtained in the simulator are analyzed and evaluated by SEM Also the results in this paper can be used for to prevent semiconductor devices from ESD hazards.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.1975-1988
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• 2024

It is important to maintain cladding integrity in spent nuclear fuel management. This study proposes a numerical analysis method to evaluate the fracture resistance of irradiated zirconium alloy cladding under pinch load known to cause Mode-III failure. The mechanical behavior and fracture of the cladding under pinch loading can be evaluated by a Ring Compression Test (RCT). To simulate the fracture of hydride precipitates, zirconium matrix, and Zr/hydride interfaces under the stress field generated by RCT, a micro-structure crack propagation simulation method based on Continuum Damage Mechanics (CDM) has been proposed. Our RCT simulation model was constructed from microscopic images of irradiated cladding. In this study, we developed an automated process to generate a pixel-based finite element model by separating the hydride precipitates, zirconium matrix, and interfaces using an image segmentation method. The appropriate element size was selected to ensure the efficiency and accuracy of a crack propagation simulation. The load-displacement curves and strain energies from RCT were compared and analyzed with the simulation results of different element sizes. The finalized RCT simulation model can be used to establish the failure criterion of fuel rods under pinch loading. The advantages and limitations of the proposed method are fully discussed here.

• 한국전자거래학회지
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• 제1권2호
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• pp.1-25
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• 1996

This study aims to provide conversion process to acquire IETM and fundamental IETMDB construction necessary for IETM. As the weapon system and other equipments are highly advanced and electronically sophisticated, the amount of information necessary to operate and maintain the systems is being dramatically increased. Thus, it is theoretically and practically impossible to maintain the huge amount of information in the paper-based manual. Furthermore, the vast amount of paper based-technical information makes it difficult to share them in real time. This paper discuss how to solve these prolems by using highly advanced information technology such as network, database, data communication, etc First, we propose an effective conversion process for the decision of IETM classes from Class 1 to Class 5. Second, we also propose a construction of IETMDB and IETM system by using CALS standard and Content Data Model (CDM).

• 천문학회보
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• 제43권1호
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• pp.62.2-62.2
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• 2018

From the gaussian, near scale-invariant density perturbations observed in the CMB to the late time clustering of galaxies, CDM provides a minimal theoretical explanation for a variety of cosmological data. However accepting this explanation, requires that we include within our cosmic ontology a vacuum energy that is ~122 orders of magnitude lower than QM predictions, or alternatively a new scalar field (dark energy) that has negative pressure. Alternatively, modifications to Einstein's General Relativity have been proposed as a model for cosmic acceleration. Recently there have been many works attempting to test for modified gravity using the large scale clustering of galaxies, ISW, cluster abundance, RSD, 21cm observations, and weak lensing. In this work, we compare various modified gravity models using cosmic shear data from the Deep Lens Survey as well as data from CMB, SNe Ia, and BAO. We use the Bayesian Evidence to quantify the comparison robustly, which naturally penalizes complex models with weak data support. In this poster we present our methodology and preliminary constraints on f(R) gravity.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1289-1294
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• 2008

Electrostatic discharge(ESD) phenomenon is a serious reliability concern. It causes approximately most of all field failures of IC. To quality the ESD immunity of IC product, there are some test methods and standards developed. ESD events have been classified into 3 models, which are HBM, MM and CDM. All the test methods are designed to evaluate the ESD immunity of IC products. This study provides an overview among ESD test methods on ICs and an efficient ESD stress method. We have estimated on all pin combination about the positive and negative ESD stress. We make out the weakest stress mode. This mode called a worst-case mode. We proposed that positive supply voltage pin and I/O pin combination is efficient because it is a worst-case mode.

• 품질경영학회지
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• 제38권4호
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• pp.512-520
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• 2010

This research is the analysis of using structural equation method in order to investigate the cause and effect relationship among the elements related to the innovation activity and the degree of the influence on that, and in order to make sure the sequential processes into the meaningful management performance for improving the efficiency and effectiveness of a various of innovation activities performing in the domestic small and medium enterprise. To perform this research, we surveyed CEOs, managers, workers working for manufacturing business, we distributed 250 sheets totally and withdrew 206 sheets. we analyzed 169 sheets that we could use for this research using SPSS 15.0 and AMOS 18.0 program.

• 소성∙가공
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• 제17권3호
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• pp.161-169
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• 2008

In the present work, the two-back stress model is proposed and continuum damage mechanics (CDM) is incorporated into the plastic constitutive relation in order to describe the plastic deformation localization and the damage evolution in a deforming continuum body. Coupling between damage mechanics and isothermal rate independent plasticity is performed using the kinematic hardening rule, which in turn is formulated by combining the nonlinear Armstrong-Frederick rule and the Phillips rule. The numerical analyses are carried out within h deformation theory. It is noted that the damage evolution within a work piece accelerates the plastic deformation localization such that the material with lower hardening exponent results in a rapid shear band formation. Moreover, the results from the numerical analysis reflected closely with the micro-structures around the fractured regime. The effects of the various hardening parameters on deformation localization are also investigated. As the nonlinear strain rate description in the back stress evolution becomes dominant, the strain localization becomes intensified as well as the damage evolution.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.645-647
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• 2017

스마트팩토리 테스트베드 구축을 위해서는 생산 공정 및 제품 테스팅을 포함한 지속적 자료 수집 환경이 요구된다. 이 논문에서는 테스팅 환경의 장치 및 센서를 정의하기 위한 CDM(Common Device Model)을 기반으로 작성된 마크업언어인 SML(Sensor Markup Language)을 기술하고 이를 기반으로 구성된 소프트웨어 센서의 활용을 기술한다. 통지 모델을 기반으로 센서로부터 수집된 센싱자료와 상태 정보를 수집하기 위한 소프트웨어 아키텍처을 설계하였으며, 이는 테스트베드 시스템 개발의 참조모델로서 사용한다.