• 대한인간공학회지
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• 제30권5호
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• pp.683-688
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• 2011

Objective: The aim of this study is to develop a distributed representative human model(DRHM) generation and analysis system. Background: DRHMs are used for a product with multiple-size categories such as clothing and shoes. It is not easy for a product designer to explore an optimal sizing system by applying various distributed methods because of their complexity and time demand. Method: Studies related to DRHM generation were reviewed and the RHM generation interfaces of three digital human model simulation systems(Jack$^{(R)}$, RAMSIS$^{(R)}$, and CATIA Human$^{(R)}$) were reviewed. Results: DRHM generation steps are implemented by providing sophisticated interfaces which offer various statistical techniques and visualization methods with ease. Conclusion: The DRHM system can analyze the multivariate accommodation percentage of a sizing system, provide body sizes of generated DRHMs, and visualize generated grids and DRHMs. Application: The DRHM generation and analysis system can be of great use to determine an optimal sizing system for a multiple-size product by comparing various sizing system candidates.

• 한국전자통신학회논문지
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• 제16권2호
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• pp.329-338
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• 2021

본 연구는 풍력발전의 합리적인 운영 계획과 에너지 저장창치의 용량산정을 위한 풍력 발전량을 예측한다. 예측을 위해 물리적 접근법과 통계적 접근법을 결합하여 풍력 발전량의 예측 방법을 제시하고 풍력 발전의 요인을 분석하여 변수를 선정한다. 선정된 변수들의 과거 데이터를 수집하여 딥러닝을 이용해 풍력 발전량을 예측한다. 사용된 모델은 Bidirectional LSTM(:Long short term memory)과 CNN(:Convolution neural network) 알고리즘을 결합한 하이브리드 모델을 구성하였으며, 예측 성능 비교를 위해 MLP 알고리즘으로 이루어진 모델과 오차를 비교하여, 예측 성능을 평가하고 그 결과를 제시한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1601-1604
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• 2003

This paper describes a split operation for generation of core and cavity plates of an injection mold for a pseudo-solid model of a plastic part. Here, a pseudo-solid model means a sheet model that looks like a solid model. but whose boundary is not closed. When a solid model created in a different CAD system is imported through standard data exchange format, a pseudo-solid model is created in most cases as tolerance or some other problems make sewing operation failed. As most existing mold design system based on solid modeling kernels require a complete part solid model, mold designers have to do time-consuming healing operations to convert a pseudo-solid to solid. The essential capability of mold design system is the split operation for generation of core and cavity plates. Thus. we developed a split operation for pseudo-solid part model to eliminate or reduce healing preprocessing for mold design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4568-4584
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• 2016

Steganography based on text generation has become a hot research topic in recent years. However, current text-generation methods which generate texts of normal style have either semantic or syntactic flaws. Note that texts of special genre, such as poem, have much simpler language model, less grammar rules, and lower demand for naturalness. Motivated by this observation, in this paper, we propose a text steganography that utilizes Markov chain model to generate Ci-poetry, a classic Chinese poem style. Since all Ci poems have fixed tone patterns, the generation process is to select proper words based on a chosen tone pattern. Markov chain model can obtain a state transfer matrix which simulates the language model of Ci-poetry by learning from a given corpus. To begin with an initial word, we can hide secret message when we use the state transfer matrix to choose a next word, and iterating until the end of the whole Ci poem. Extensive experiments are conducted and both machine and human evaluation results show that our method can generate Ci-poetry with higher naturalness than former researches and achieve competitive embedding rate.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.848-853
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• 2005

3D geometric modeling of an object of interest has been intensively investigated in many fields including CAD/CAM and computer graphics. Traditionally, CAD and geometric modeling tools are widely used to create geometric models that have nearly the same shape of 3D real objects or satisfy designers intent. Recently, with the help of the reverse engineering (RE) technology, we can easily acquire 3D point data from the objects and create 3D geometric models that perfectly fit the scanned data more easily and fast. In this paper, we present 3D geometric model generation based on a stereo vision system (SVS) using random pattern projection. A triangular mesh is considered as the resulting geometric model. In order to obtain reasonable results with the SVS-based geometric model generation, we deal with many steps including camera calibration, stereo matching, scanning from multiple views, noise handling, registration, and triangular mesh generation. To acquire reliable stere matching, we project random patterns onto the object. With experiments using various random patterns, we propose several tips helpful for the quality of the results. Some examples are given to show their usefulness.

• 대한교통학회지
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• 제18권4호
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• pp.95-105
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• 2000

본 연구의 목적은 기존의 대표적 통행발생모형인 회귀모형과 신경망 이론에 의한 통행발생모형을 비교.분석하여 통행발생모형에 대한 새로운 방법을 제시하고자 하는 것이다. 이를 위해 모형의 검정력과 안정성을 현재적 설명력과 장래 예측력의 결합으로 전제하고, 시나리오에 따른 모형의 검정력 변화를 통한 안정성 평가를 수행하였다. 연구결과 역전파 신경망 모형(Backpropagation Neural Networks)은 회귀모형의 검정력과 안정성을 상회하는 우수한 결과를 보여 주었으며, 이는 향후 통행발생 모형으로 역전파 신경망 모형의 적용 가능성을 의미하는 것으로 해석된다. 특히 복잡해진 교통현상과 다양한 수집자료를 고려할 때 교통분야에서의 신경망 모형의 적용은 더욱 확대될 전망이다.

• 항공우주시스템공학회지
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• 제17권2호
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• pp.9-15
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• 2023

인공위성의 축소 열모델 생성 작업은 궤도 열해석의 시간 단축과 발사체 연동 열해석 수행을 위해 인공위성 제작 프로젝트에서 반드시 한 번 이상 수행하게 된다. 축소 열모델 생성 방법은 여러가지가 거론되고 있지만, 실무적으로는 직관적이면서도 편리한 등온격자생성법이 가장 많이 사용되고 있다. 그러나 아직까지 등온격자생성법의 자동화에 관한 연구는 부족한 실정이다. 본 논문에서는 온도 허용오차와 고정 노드를 고려한 등온격자생성법 기반 위성 축소 열모델 자동 생성 방법을 제안하였다. 서로 다른 세 가지의 온도 허용오차 케이스를 이용하여 방법론을 검증하였으며, 평균 온도 차이는 ECSS의 축소 열모델 생성 가이드라인(< 2 K)을 만족함을 확인할 수 있었다.

• Smart Structures and Systems
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• 제30권5호
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• pp.501-511
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• 2022

Three-dimensional (3D) models have become crucial for improving civil infrastructure analysis, and they can be used for various purposes such as damage detection, risk estimation, resolving potential safety issues, alarm detection, and structural health monitoring. 3D point cloud data is used not only to make visual models but also to analyze the states of structures and to monitor them using semantic data. This study proposes automating the generation of high-quality 3D point cloud data and removing noise using deep learning algorithms. In this study, large-format aerial images of civilian infrastructure, such as cut slopes and dams, which were captured by drones, were used to develop a workflow for automatically generating a 3D point cloud model. Through image cropping, downscaling/upscaling, semantic segmentation, generation of segmentation masks, and implementation of region extraction algorithms, the generation of the point cloud was automated. Compared with the method wherein the point cloud model is generated from raw images, our method could effectively improve the quality of the model, remove noise, and reduce the processing time. The results showed that the size of the 3D point cloud model created using the proposed method was significantly reduced; the number of points was reduced by 20-50%, and distant points were recognized as noise. This method can be applied to the automatic generation of high-quality 3D point cloud models of civil infrastructures using aerial imagery.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권2호
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• pp.112-119
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• 2003

This paper proposes a model of SP(silent period) generation in masseter muscle by means of computer simulation. The model is based on the anatomical and physiological properties of trigeminal nervous system. In determining the SP generation pathway, evoked SPs of masseter muscle after mechanical stimulation to the chin are divided into normal and abnormal group. Normal SP is produced by the activation of mechanoreceptors in periodontal ligament. The activation of nociceptors contributes to the latter part of normal SP, abnormal extended SP is produced. As a result, the EMG signal generated by a proposed SP generation model is similar to both real EMG signal including normal SP and abnormal extended SP with TMJ patients. The result of this study have shown differences of SP generation mechanism between subjects both with and without TMJ dysfunction.

• 한국정밀공학회지
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• 제21권6호
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• pp.69-76
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• 2004

This paper presents a prediction model for the aerosol generation of cutting fluid in turning process. Experimental studies have been carried out in order to identify the characteristics of aerosol generation in non-cutting and cutting cases. The indices of aerosol generation was mass concentration comparable to number generation, which is generally used fur environment criterion. Based on the experimental data, empirical model for predicting aerosol mass concentration of cutting fluid could be obtained by a statistical analysis. This relation shows good agreement with experimental data.