• 한국정밀공학회지
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• 제11권1호
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• pp.138-149
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• 1994

This paper introduces a new monitoring technique which utilizes an adaptive signal processing for feature generation, coupled with a multilayered merual network for pattern recognition. The cutting force signal in face milling operation was modeled by a low order discrete autoregressive model, shere parameters were estimated recursively at each sampling instant using a parameter adaptation algorithm based on an RLS(recursive least square) method with discounted measurements. The influences of the adaptation algorithm parameters as well as some considerations for modeling on the estimation results are discussed. The sensitivity of the extimated model parameters to the tool state(new and worn tool)is presented, and the application of a multilayered neural network to tool state monitoring using the previously generated features is also demonstrated with a high success rate. The methodology turned out to be quite suitable for in-process tool wear monitoring in the sense that the model parameters are effective as tool state features in milling operation and that the classifier successfully maps the sensors data to correct output decision.

• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.330-343
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• 2017

Climate change is an important issue, with many researches examining not only future climatic conditions, but also the interaction of climate and air quality. In this study, a new version of the emissions processing software tool - Python-based PRocessing Operator for Climate and Emission Scenarios (PROCES) - was developed to support climate and atmospheric chemistry modeling studies. PROCES was designed to cover global and regional scale modeling domains, which correspond to GEOS-Chem and CMAQ/CAMx models, respectively. This tool comprises of one main system and two units of external software. One of the external software units for this processing system was developed using the GIS commercial program, which was used to create spatial allocation profiles as an auxiliary database. The SMOKE-Asia emissions modeling system was linked to the main system as an external software, to create model-ready emissions for regional scale air quality modeling. The main system was coded in Python version 2.7, which includes several functions allowing general emissions processing steps, such as emissions interpolation, spatial allocation and chemical speciation, to create model-ready emissions and auxiliary inputs of SMOKE-Asia, as well as user-friendly functions related to emissions analysis, such as verification and visualization. Due to its flexible software architecture, PROCES can be applied to any pregridded emission data, as well as regional inventories. The application results of our new tool for global and regional (East Asia) scale modeling domain under RCP scenario for the years 1995-2006, 2015-2025, and 2040-2055 was quantitatively in good agreement with the reference data of RCPs.

• 제어로봇시스템학회논문지
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• 제22권4호
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• pp.307-314
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• 2016

Recently, demands on the tapping machine are increased due to the case of a cell phone is changed to metal such as aluminum. The automatic tool changer (ATC) is one of the most important devices for the tapping machine related to the speed and energy consumption of the machine. To reduce the consumed energy and vibration, the dynamic modeling is essential for the ATC. In this paper, inverse dynamic modeling of a novel ATC mechanism is introduced. The proposed ATC mechanism is composed of a double four-bar mechanism with a circular tablet to generate continuous rotation of the tablet. The dynamic modeling is performed based on the Lagrange equation with a modeling for the contact between the four-bar and the tablet. Simulation results for various working conditions are proposed and analyzed for the prototype design. The dynamic modeling can be applied to determine the proper actuator and to reduce the vibration and consumed energy for the ATC machine.

• 한국컴퓨터산업학회논문지
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• 제5권1호
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• pp.177-182
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• 2004

소나 센서부 설계 시 개별 센서에 대한 정합회로의 설계는 전체 가중회로의 특성에 매우 큰 영향을 미친다. 그러나 많은 경우 정합회로를 설계하는데 있어서 경험에 의한 수작업으로 수행하거나 매우 간단한 모델을 설정하여 그것을 바탕으로 설계하는 예가 많다. 다양한 센서에 대해서 유연하게 대응하는데 한계를 갖고 있고 또 많은 오류를 동반하기 때문에 정합회로 설계에 많은 시행착오를 초래한다. 본 연구에서는 다양한 센서에 유연하게 대응하는 정합회로 설계 도구를 구성하는 첫 단계로써 실제 소나 센서의 특성 측정 및 그를 바탕으로 한 소자 모델링을 일괄 작업화한 설계 프로그램을 구성하여, 그 구성과 기능에 대해서 설명하고자 한다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.401-411
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• 2003

Tube expanding process is for combining a heat-sink plate with hair-pins (Cu-tube) through plastic deformation. The two parts, i. e. , heat-sink plate and hair-pins are they components of a heat-exchanger for an air conditioner. This paper presents the analysis and dynamic modeling of a high-speed tube expander which integrates transfer of parts, fixing of parts, and tube expanding into one process. The 3-dimensional modeling of all the parts for the tube-expander was constructed using CATIA$\circledR$. then the CATIA$\circledR$ models are transferred into visuaINastran$\circledR$ to execute the 3-dimensional animation for checking prescribed cycle-time. The technique presented in this paper has been shown to be effective as a priori tool for verifying the design of a high-speed tube expander.

• 한국정밀공학회지
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• 제20권12호
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• pp.135-141
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• 2003

For the analysis of machined surface topography and machine-tool chatter, the cutting system is considered to be a single degree of freedom system. This paper presents a modeling method of equivalent vibratory system for precision cutting in end-milling using an impact test, an Autoregressive Moving Average (ARMA) mode] and a bisection method It has been shown that the proposed modeling method provides a good identification of the cutting system. The advantages of the proposed method in comparison to the existing method are that it is very easy and accurate.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.429-435
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• 2006

In this study multi-zone modeling program CONTAM 2.4 which is developed by NIST is used for modeling the air disinfection system which is consist of dilution, filtration, ultra violet germicidal irradiation (UVGI) for removing the indoor microorganism such as bacteria and fungus. Developed models those protect occupants against indoor microorganism generated in our daily life are enable to use for immune building simulation tool. Also, results indicate that those models are enable to compute the real situation that is almost impossible of carrying out experiment and identify the disinfection rate with highly reliance. Results also suggest that engineers will use these models as a design tool for the immune building system.

• 경영과학
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• 제11권1호
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• pp.59-72
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• 1994

In this paper we examine potentials of a spreadsheet program, one of the most widly available software system, as a mathematical optimization modeling tool. For an illustrative example, a shortest path problem is modeled on Lotus-123 for practical use and an implementational framework and a general guide to the spreadsheet modeling of network analysis is provided.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.129-130
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.133-134
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• 2010