• 한국건설관리학회논문집
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• 제7권4호
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• pp.91-99
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• 2006

본 연구는 신축 교육시설 프로젝트의 개념단계에서 공사비를 예측하기 위한 인공신경망모델의 제안을 목적으로 한다. 현행 공공 교육시설의 개념단계 공사비예측에는 기본인자인 연면적에 의한 단일변수 모델이 적용되고 있다. 그러나 개념단계에서 단일변수 공사비예측모델을 적용하여 예측된 공사비는 그 오차범위가 크고, 실시설계 완료 후 물량산출에 의해 산정된 상세공사비와 비교하여 큰 차이를 보일 경우 프로젝트의 수정이 불가피하며, 이는 프로젝트의 비용을 증가시키고 공기를 지연시킨다. 그러므로 본 연구에서는 교육시설 프로젝트의 사업계획 수립 및 예산확보 과정에서 공사비예측에 적용이 가능한다 변수 인공신경망모델을 제안하였다. 개발된 모델을 평가한 결과 평균오차율이 6.82%로써, 평균 93.18%의 정확도를 기록하였다. 제안된 인공신경망모델은 지난 5년간 신축된 교육시설의 공사예정금액을 실적자료로 사용하여 학습되었기 때문에, 차후 교육시설 신축공사의 예산편성에 그 활용이 기대된다.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.9-17
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• 2022

As the COVID-19 pandemic situation worsens, the time spent indoors increases, and the exposure to indoor environmental pollution such as indoor air pollution and noise also increases, causing problems such as deterioration of human health, stress, and discord between neighbors. This paper designs and implements a system that measures and monitors indoor air quality and noise, which are representative evaluation criteria of the indoor environment. The system proposed in this paper consists of a particulate matter measurement subsystem that measures and corrects the concentration of particulate matters to monitor indoor air quality, and a noise measurement subsystem that detects changes in sound and converts it to a sound pressure level. The concentration of indoor particulate matters is measured using a laser-based light scattering method, and an error caused by temperature and humidity is compensated in this paper. For indoor noise measurement, the voltage measured through a microphone is basically measured, Fourier transform is performed to classify it by frequency, and then A-weighting is performed to correct loudness equality. Then, the RMS value is obtained, high-frequency noise is removed by performing time-weighting, and then SPL is obtained. Finally, the equivalent noise level for 1 minute and 5 minutes are calculated to show the indoor noise level. In order to classify noise into direct impact sound and air transmission noise, a piezo vibration sensors is mounted to determine the presence or absence of direct impact transmitted through the wall. For performance evaluation, the error of particulate matter measurement is analyzed through TSI's AM510 instrument. and compare the noise error with CEM's noise measurement system.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.792-799
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• 2022

Building Information Modeling (BIM) technology is a key component of modern construction engineering and project management workflows. As-is BIM models that represent the spatial reality of a project site can offer crucial information to stakeholders for construction progress monitoring, error checking, and building maintenance purposes. Geometric methods for automatically converting raw scan data into BIM models (Scan-to-BIM) often fail to make use of higher-level semantic information in the data. Whereas, semantic segmentation methods only output labels at the point level without creating object level models that is necessary for BIM. To address these issues, this research proposes a hybrid semantic-geometric approach for clutter-resistant floorplan generation from laser-scanned building point clouds. The input point clouds are first pre-processed by normalizing the coordinate system and removing outliers. Then, a semantic segmentation network based on PointNet++ is used to label each point as ceiling, floor, wall, door, stair, and clutter. The clutter points are removed whereas the wall, door, and stair points are used for 2D floorplan generation. A region-growing segmentation algorithm paired with geometric reasoning rules is applied to group the points together into individual building elements. Finally, a 2-fold Random Sample Consensus (RANSAC) algorithm is applied to parameterize the building elements into 2D lines which are used to create the output floorplan. The proposed method is evaluated using the metrics of precision, recall, Intersection-over-Union (IOU), Betti error, and warping error.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.97-100
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• 2005

우리는 페이딩 환경에서 비동기 블록 수신 CPFSK에 적용되는 TCM의 성능을 분석하였다. 여기서 비동기 블록 수신기는 N개의 심볼을 하나의 블록으로 취급하여 비동기 복조를 수행한다. 일반적으로 이러한 블록 수신 방식은 관찰 블록의 길이가 길어질수록 더 좋은 성능을 나타낸다. 그러나 페이딩의 응집 시간이 수신기의 관찰 블록 길이 보다 작아지면, 블록 수신기의 오류 성능은 매우 나빠지게 된다. 본 논문에서는 페이딩의 응집 시간이 수신기의 관찰 블록 시간 NT(여기서, T는 심볼 시간)보다 큰 환경을 저속 페이딩 환경 이라고 하고, 그렇지 않은 환경을 고속 페이딩 환경이라고 정의하여, 각각의 환경에서 시스템의 성능을 분석하였다. 그 결과 고속 페이딩 환경에서 비동기 블록 수신기의 사용은 오류 층(error floor) 현상을 초래한다는 사실을 알 수 있었다. 따라서 고속 페이딩 환경에서는 수신기의 관찰 블록 길이를 짧게 하는 것이 더 좋다.

• 한국CDE학회논문집
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• 제9권2호
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• pp.133-142
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• 2004

CAMPfonn2D is a Finite Element Method (FEM) based process simulation system designed to analyze two dimensional (2D) flow of various metal forming processes. It enables designers to analyze metal forming processes on the computer rather than the shop floor using trial and error and provides vital information about material and thermal flow during the forming process to facilitate the design of products. CAMPfonn2D can be used by companies, research institutes and industrial applications to analyze forging, extrusion, drawing, heading, upsetting and many other metal forming processes. Also, process simulation using CAMPfonn2D can be instrumental in cost, quality and delivery improvements at leading companies. Today's competitive pressures require companies to take advantage of every tool for rapid manufacturing of well-designed product. So, the preprocessor of simulation program must be easy to use to speed-up design. In this paper, we introduce new version of Preprocessor and show how easy to use it. And, Preprocessor will prove itself to be easy and extremely effective.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.658-663
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• 2005

This paper presents the steering control algorithm of a locomotion robot using a quaternion. The locomotion robot is to be moved on an irregular floor that can inevitably result in the errors of both position and orientation. Especially the orientation error should be compensated every work in order to adjust the misaligned values of current orientation to those commanded values. In this paper, we propose a new steering control algorithm between the two values by using a quaternion with spherical cubic interpolation. The proposed algorithm is shown to be effective in terms of vibration when compared to a conventional simple compensation without interpolation, by using $MATLAB^{(R)}$ and $VisualNastran4D^{(R)}$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.826-829
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• 2008

In a field measurement, measurement errors are produced by measuring environments and systematic errors in the measurement procedure. Measurement errors can be expressed as a measurement uncertainty. In this study, the measurement uncertainty and various measuring factors are investigated in heavy-weight impact sounds. According to KS 2810-2, the model functions, which is the estimation of the maximum SPL measurement in each octave band frequency, are determined. From this estimation model, 3.53dB is shown in 63Hz. This level is caused by the sound field of the receiving room, which does not meet the diffusing field.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.1113-1116
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• 1999

For mobile robot, the navigation effectiveness can be improved by providing autonomy, but this autonomy requires the mobile robot to detect unknown obstacles and avoid collisions while moving it toward the target. This paper presents an effective method for autonomous navigation of the mobile robot in structured environments. This method uses ultrasonic sensor array to detect obstacles and utilizes force relationship between the obstacles and the target for avoiding collisions. Accuracy of sensory data produced by ultrasonic sensors is improved by employing error eliminating rapid ultrasonic firing (EERUF) technique. Navigation algorithm controlling both the velocity and steering simultaneously is developed, implemented to the mobile robot and tested on the floor filled with the cluttered obstacles. It is verified that from the results of the field tests the mobile robot can move at a maximum speed of 0.66 m/sec without any collisions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.201-205
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• 2002

In case of fire in the buildings, the appropriate and safe evacuation plans for the building residents are very important to minimize the number of casualties. Since the evacuation time usually depends on the stairs and passages of design of the building, the evacuation plans should be considered while the architectural design is done. Conventionally, the calculation of the evacuation time in the case of fire breakout is based on the approximate mathematical equations which are prone to error. In this study, the simulation software is developed to help the architectural designers to access the more accurate evacuation time and find out the floor plans which offers the most sage evacuation plans for the residents in case of fire.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.34-36
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• 2002

This paper addresses an elevator position control scheme in unified control system. Conventional systems have employed independent micro-processors for speed, car, and group control respectively and the car controller generates a velocity command by combining the time-based and distance-based velocity pattern. In this scheme, it is inevitable that an elevator creeps in the vicinity of target floor, or stops abruptly. The proposed control system employs only one high-performance micro-processor, which can execute the car and group control as well as the speed control. It simply generates the desired position trajectory based on time and on-line corrects a velocity pattern to make the position error be zero. Experimental results show the feasibility of the proposed control scheme.