• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.321-323
• /
• 2015

Monitoring crane motion in real time is the first step to identifying and mitigating crane-related hazards on construction sites. However, no accurate and reliable crane motion capturing technique is available to serve this purpose. The objective of this research is to explore a method for real-time crane motion capturing and investigate an approach for assisting hazard detection. To achieve this goal, this research employed various techniques including: 1) a sensor-based method that accurately, reliably, and comprehensively captures crane motions in real-time; 2) computationally efficient algorithms for fusing and processing sensing data (e.g., distance, angle, acceleration) from different types of sensors; 3) an approach that integrates crane motion data with known as-is environment data to detect hazards associated with lifting tasks; and 4) a strategy that effectively presents crane operator with crane motion information and warn them with potential hazards. A prototype system was developed and tested on a real crane in a field environment. The results show that the system is able to continuously and accurately monitor crane motion in real-time.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2022년도 추계학술대회
• /
• pp.168-169
• /
• 2022

In this study, we investigates the auto-berthing problem for the underactuated surface vessel in the presence of constraints of dynamic uncertainties, finite time, transmission load, and environmental disturbance. A novel control scheme is proposed by fusing the finite time control technology and the event-triggered input algorithm. In the algorithm, differential homeomorphism coordinate the transformation is used to solve the problem of underactuation. Then, we apply the finite time technology and event triggered to save the time of the berthing vessel and relieve transmission burden between the controller and the vessel respectively. Moreover, a radial basis function network is used to approximate unknown nonlinear functions, and minimum learning parameters are introduced to lessen the computational complexity. A sufficient effort has been made to verify the stability of the closed-loop system based on the Lyapunov stability theory. Finally, simulation results display the effectiveness of the proposed scheme.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.595-597
• /
• 2004

In this paper range measurement systems using ultrasonic and visual sensors are designed. By varying the focus of a camera, the range to a target pattern is computed. Pour different methods are tested for the focusing-based range measurement. The best result is obtained when counting edge pixels found by Laplacian operator. Higher accuracy can be obtained by fusing the measurement of camera focusing with that of ultrasonic sensor. The system designed is experimented within the range of 300-450mm.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.328-335
• /
• 2022

With the advance of robot capabilities and functionalities, construction robots assisting construction workers have been increasingly deployed on construction sites to improve safety, efficiency and productivity. For close-proximity human-robot collaboration in construction sites, robots need to be aware of the context, especially construction worker's behavior, in real-time to avoid collision with workers. To recognize human behavior, most previous studies obtained 3D human poses using a single camera or an RGB-depth (RGB-D) camera. However, single-camera detection has limitations such as occlusions, detection failure, and sensor malfunction, and an RGB-D camera may suffer from interference from lighting conditions and surface material. To address these issues, this study proposes a novel method of 3D human pose estimation by extracting 2D location of each joint from multiple images captured at the same time from different viewpoints, fusing each joint's 2D locations, and estimating the 3D joint location. For higher accuracy, the probabilistic representation is used to extract the 2D location of the joints, considering each joint location extracted from images as a noisy partial observation. Then, this study estimates the 3D human pose by fusing the probabilistic 2D joint locations to maximize the likelihood. The proposed method was evaluated in both simulation and laboratory settings, and the results demonstrated the accuracy of estimation and the feasibility in practice. This study contributes to ensuring human safety in close-proximity human-robot collaboration by providing a novel method of 3D human pose estimation.

• Journal of Chest Surgery
• /
• 제23권6호
• /
• pp.1067-1073
• /
• 1990

To clarify the changes of left ventricular function under normothermia, the time interval between the onset of ischemia and the beginning of contracture of left ventricle[TIC] were recorded in newborn piglet. Myocardial performance was assessed using intraventricular balloon to determine compliance and systolic function after 5 to 10 minutes interval per-fusing normothermic substrate free Krebs solution as a perfusate. The time to onset TIC was 29.5\ulcorner1.7 minutes and peak ischemic contracture was 46.7\ulcorner4.0 minutes[p<0.01]. In myocardial performance, systolic function of left ventricle[defined as cardiac contractility] was kept until 25 minutes of perfusion, but was decreased abruptly after 30 minutes of perfusion[p<0.0018] and diastolic function of left ventricle[defined as diastolic compliance] was kept until 15 minutes of perfusion, but was decreased after 20 minutes of perfusion [p=0.00\ulcorner9]. This study demonstrated maximal time of the tolerance to normothermic global ischemia and functional changes of left ventricle using Krebs perfusate under the same condition.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
• /
• pp.3-8
• /
• 1992

The theory of subjective preference with temporal and spatial factors which include sound signals arriving at both ears is described. Then, auditory evoked potentials which may relate to a primitive subjective response namely subjective preference are discussed. According to such fundamental phenomena, a workable model of human auditory-brain system is proposed. For eample, important subjective attributes, such as loudness, coloration, threshold of preception of a reflection and echo distrubance as well as subjective preference in relation to the initial time delay gap between the direct sound and the first reflection, and the subsequent reverberation time are well described by the autocorrelation function of source signals. Speech clarity, subjective diffuseness as well as subjective preference are related to the magnitude of inter-aural crosscorrelation function (IACC). Even the caktail party effects may be eplained by spatialization of human brain, i.e., independence of temporal and spatial factors.

• 한국인터넷방송통신학회논문지
• /
• 제23권4호
• /
• pp.79-84
• /
• 2023

최근 분산 및 병렬 처리 기술 중 빠른 처리 속도를 제공하는 Apache Spark는 실시간 기능 및 머신러닝 기능을 제공하고 있다. 이러한 기능에 대한 공식 문서 가이드가 제공되고 있지만, 기능들을 융합하여 실시간으로 특정 값을 예측하는 방안은 제공되고 있지 않다. 따라서 본 논문에서는 이러한 기능들을 융합하여 실시간으로 데이터의 값을 예측할 수 있는 연구를 진행했다. 전체적인 구성은 Python 프로그래밍 언어에서 제공하는 주가 데이터를 다운로드하여 수집한다. 그리고 머신러닝 기능을 통해 회귀분석의 모델을 생성하고, 실시간 스트리밍 기능을 머신러닝 기능과 융합하여 실시간으로 주가 데이터 중 조정종가를 예측한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권6호
• /
• pp.3092-3107
• /
• 2019

Visible-infrared image fusion is a process of synthesizing an infrared image and a visible image into a fused image. This process synthesizes the complementary advantages of both images. The infrared image is able to capture a target object in dark or foggy environments. However, the utility of the infrared image is hindered by the blurry appearance of objects. On the other hand, the visible image clearly shows an object under normal lighting conditions, but it is not ideal in dark or foggy environments. In this paper, we propose a multi-guided filter and a real-time image fusion method. The proposed multi-guided filter is a modification of the guided filter for multiple guidance images. Using this filter, we propose a real-time image fusion method. The speed of the proposed fusion method is much faster than that of conventional image fusion methods. In an experiment, we compare the proposed method and the conventional methods in terms of quantity, quality, fusing speed, and flickering artifacts. The proposed method synthesizes 57.93 frames per second for an image size of $320{\times}270$. Based on our experiments, we confirmed that the proposed method is able to perform real-time processing. In addition, the proposed method synthesizes flicker-free video.

• 대한공간정보학회지
• /
• 제2권2호
• /
• pp.81-88
• /
• 1994

CNS(Car Navigation System)는 국내외적으로 자율주행차량(Autonomous Land Vehicle)연구분야에서 주행계획 용도보다는 일반차량에서 운전자 보조 시스템으로 더 많이 쓰이고 있다. 본 논문에서는 CNS에 한 연구분야인 Global Path Planning의 새로운 위치추적 알고리즘 결과를 개발하였다. 일본과 같은 경우에는 벌써 이러한 CNS의 연구가 활발히 진행되어서 현재는 상품화되어 년간 $40{\sim}50$만개 정도가 팔리고 있고 미국 및 유럽 각국(EC)에서도 CNS의 개발 및 상품화가 활발히 진행되고 있다. 우리나라의 경우엔 아직 주행중인 차량의 현재위치를 구하고 이를 Digital Map상에 실시간으로 구현하는 제 1세대 CNS가 연구 중에 있으나 아직은 초기 단계에 있다. 이에 본 논문은 현재까지 우리나라에서 연구중인 인공위성과 범지구적 위치결정체계(Global Positioning System)만을 이용한 차량 위치 추정 방법에 추측항법체계(Dead_Reckoning)라는 다른 방법을 결합하여 기존의 차량 위치 추정 오차를 줄여주는 새로운 알고리즘을 제시하고 실제차량에서의 실험결과를 보인다.

• 한국생산제조학회지
• /
• 제26권2호
• /
• pp.158-165
• /
• 2017

This study investigated spraying factors applicable to stripper usage. Cyclodextrine, as environment-friendly material, was included in the stripper composition. An efficient spray technology was applied for the Photoresist strip. For industrial applications, stripping requires a temperature below $50^{\circ}C$, a strip time within 50 s, and chemically stable activation. Spraying factors were organized considering many conditions-orifice diameter, working pressure (inlet speed), spray distance, and spray angle. For commercial practicability, the flow rate was limited to 3 L/min. The nozzle parameters were nozzle orifice diameter of 1.8-2.2 mm, spray distance of 40-60 mm, and injection speed of 0.7-1.2 m/s. Through the thermal spray movement of the fluid, the thermal boundary layer for a chemical reaction just above the ITO-glass surface and momentum region for sufficient agitation (above 4 m/s) was achieved.