• 대한기계학회논문집A
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• 제24권10호
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• pp.2451-2460
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• 2000

In order to minimize straightness error of deflected shaft, a geometric adaptive straightness controller system is studied. A multi-step straightening and a three-point bending process have been developed for the geometric adaptive straightness controller. Load-deflection relationship, on-line identification of variations of material properties, on-line springback prediction, and real-time hydraulic control methodology are studied for the three-point bending process. By deflection pattern analysis and fuzzy self-learning method in the multi-step straightening process, a straightening point and direction, desired permanent deflection and supporting condition are determined. An automatic straightening machine has been fabricated for rack bars by using the developed ideas. Validity of the proposed system is verified through experiments.

• 한국통신학회논문지
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• 제37B권12호
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• pp.1128-1137
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• 2012

본 논문에서는 노드의 이동성이 크고 노드의 밀도가 균일 하지 않은 애드혹 네트워크에서 라우팅 성능을 개선하기 위해 노드의 이동성과 밀도를 고려하여 OLSR(Optimized Link State Routing) 의 MPR(Multi-Point Relay) 선택방법을 개선할 수 있는 방법을 제안한다. OLSR의 MPR 선택 방법은 노드의 이동성과 밀도에 무관하게 2홉 이웃 노드를 많이 포함하는 노드를 위주로 선택한다. 하지만 노드가 이동성을 갖는 경우에 이동성이 큰 노드를 MPR로 선택할 경우 성능이 저하될 수 있다. 또한 노드의 밀도가 균일 하지 않은 경우에는 밀도가 높은 지역의 노드들이 우선적으로 MPR로 선택되면 네트워크 전체의 성능을 향상시킬 수 있다. 따라서 본 논문에서는 노드의 이동성과 밀도를 Hello 메시지 교환을 통해 측정하고 노드의 이동성과 밀도를 반영하여 MPR 선택에 우선순위를 부여하는 방법을 제안한다. 본 논문에서 제안한 MPR 선택 방법의 성능을 알아보기 위해 OPNET을 활용하여 시뮬레이션을 수행하고 제안 방법의 성능이 가장 우수함을 보인다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.708-712
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• 2008

Piles and pile foundations have been in common use since very early times. Usually function of piles is to carry load to a depth at which adequate support is available. Another important use of piles is to furnish lateral support and nowadays it is getting highlighted due to the wind load, lateral action of earthquake, and so on. After Broms (1964), many researchers have been suggested methods for estimating lateral capacity of pile. But each method assumes different earth pressure distribution and lateral earth pressure coefficient and it gives confusion to pile designers. Lateral earth pressure, essential in lateral capacity estimation, influenced by pile's behavior under lateral load. Prasad and Chari (1999) assumed the rotation point of pile and suggested an equation of ultimate lateral load capacity. In this study, we investigate the depth of rotation point in both homogeneous soil and multi layered soil, and compare to the estimation value by previous research. To model the pile set up in the sand, we use the chamber and small scale steel pile, and rain drop method. Test results show the rotation point is formed where the Prasad and Chari's estimation value, and they also show multi layered condition affects to location of rotation point to be scattered.

• 호남수학학술지
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• 제42권2호
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• pp.391-409
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• 2020

In the current paper, the intuitionistic fuzzy normed space version of Hyers-Ulam stability for multi-additive, multi-cubic and multi-additive-cubic mappings by using a fixed point method are studied. Moreover, a few corollaries corresponding to some known stability and hyperstability outcomes in intuitionistic fuzzy normed space are presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2585-2598
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• 2015

Hand posture recognition has played a very important role in Human Computer Interaction (HCI) and Computer Vision (CV) for many years. The challenge arises mainly due to self-occlusions caused by the limited view of the camera. In this paper, a robust hand posture recognition approach based on 3D point cloud from two RGB-D sensors (Kinect) is proposed to make maximum use of 3D information from depth map. Through noise reduction and registering two point sets obtained satisfactory from two views as we designed, a multi-viewed hand posture point cloud with most 3D information can be acquired. Moreover, we utilize the accurate reconstruction and classify each point cloud by directly matching the normalized point set with the templates of different classes from dataset, which can reduce the training time and calculation. Experimental results based on posture dataset captured by Kinect sensors (from digit 1 to 10) demonstrate the effectiveness of the proposed method.

• Korean Journal of Acupuncture
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• 제28권4호
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• pp.41-48
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• 2011

Objectives : This study aimed to explore the passive multi-channel time series analysis method by measuring bio-potentials of acupuncture point and the peripheral region Methods : Bio-potential was measured at ST36 and the peripherical region of ST36 of 5 healthy volunteers at three times. The diagram of the potential changes over time were smoothed by moving average method and similarities of ST36 and the other points were calculated. Results : In the normal weight group, bio-potential similarity tended to decrease in proportion to the distance from the acupuncture point. In the obesity group, bio-potential similarity appeared in a very wide area. Bio-potential similarity had positive correlation with BMI value. Conclusions : The passive multi-channel time series analysis method showed the possibility be appropriate for the electrical characteristics study of meridians.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.220-223
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• 2008

Large curved plate blocks are widely used to construct hull structure in shipbuilding industry. Most curved plates are manufactured by using manual method called as line heating that use deformation caused by residual stress after local heating along a line which is perpendicular to the curvature direction. However, its working environment is poor and its formability is totally dependent on an experienced technician. In view of that, multi-point dieless forming (MDF) technology that use reconfigurable punch arrays instead of one piece die is proposed in this study. The MDF process is based on a concept of equivalent die surface made by numbers of punches which has round tip at the end of it. In this study, numerical simulation for common curvature type such as saddle shape was carried out. In addition, experiments in the plate forming process were also conducted to compare with the numerical results in view of final configuration. Consequently, it was noted that the proposed dieless forming method has considerable feasibility to substitute the new process for conventional manual method.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.422-424
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• 2021

In this paper, it leads the approach of fusing multiple RGB cameras for visual objects recognition based on deep learning with convolution neural network and 3D Light Detection and Ranging (LiDAR) to observe the environment and match into a 3D world in estimating the distance and position in a form of point cloud map. The goal of perception in multiple cameras are to extract the crucial static and dynamic objects around the autonomous vehicle, especially the blind spot which assists the AV to navigate according to the goal. Numerous cameras with object detection might tend slow-going the computer process in real-time. The computer vision convolution neural network algorithm to use for eradicating this problem use must suitable also to the capacity of the hardware. The localization of classified detected objects comes from the bases of a 3D point cloud environment. But first, the LiDAR point cloud data undergo parsing, and the used algorithm is based on the 3D Euclidean clustering method which gives an accurate on localizing the objects. We evaluated the method using our dataset that comes from VLP-16 and multiple cameras and the results show the completion of the method and multi-sensor fusion strategy.

• 대한조선학회논문집
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• 제42권2호
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• pp.175-182
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• 2005

It is necessary to develop an efficient optimization technique to optimize the engineering structures which have given design spaces, discrete design values and several design goals. As optimization techniques, direct search method and stochastic search method are widely used in designing of engineering structures. The merit of the direct search method is to search the optimum points rapidly by considering the search direction, step size and convergence limit. And the merit of the stochastic search method is to obtain the global optimum points by spreading point randomly entire the design spaces. In this paper, a Pareto optimal based multi-objective function method (PMOFM) is developed by considering the search direction based on Pareto optimal points, step size, convergence limit and random search generation . The PMOFM can also apply to the single objective function problems, and can consider the discrete design variables such as discrete plate thickness and discrete stiffener spaces. The design results are compared with existing Evolutionary Strategies (ES) method by performing the design of double bottom structures which have discrete plate thickness and discrete stiffener spaces.

• 대한기계학회논문집A
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• 제25권5호
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• pp.841-849
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• 2001

The pixel information of the object was obtained sequentially and pixels were clustered to a label by the line labeling method. Feature points were determined by finding the slope for edge pixels after selecting the fixed number of edge pixels. The slope was estimated by the least square method to reduce the detection error. Once a matching point was determined by comparing the feature information of the object and the pattern, the parameters for translation, scaling and rotation were obtained by selecting the longer line of the two which passed through the matching point from left and right sides. Finally, modified Hausdorff Distance has been used to identify the similarity between the object and the given pattern. The multi-label method was developed for recognizing the patterns with more than one label, which performs the modified Hausdorff Distance twice. Experiments have been performed to verify the performance of the proposed algorithm and method for simple target image, complex target image, simple pattern, and complex pattern as well as the partially hidden object. It was proved via experiments that the proposed image matching algorithm for recognizing the object had a good performance of matching.