• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1549-1552
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• 1997

In this paper, a optimal algorithm that can produce the FOV is proposed in terms of using the Kohonen's Self-Organizing Map(KSOM). A FOV, that stands for "Field Of View", means maximum area where a camera could be wholly seen and influences the total time of inspection of vision system. Therefore, we draw algorithm with a KSOM which aims to map an input space of N-dimensions into a one-or two-dimensional lattice of output layer neurons in order to optimize the number and location of FOV, instead of former sequentila method. Then, we show demonstratin through computer simulation using the real PCB data. PCB data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3217-3238
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• 2018

In this paper, a depth image up-sampling method is put forward by using pixel classifying and jointed bilateral filtering. By analyzing the edge maps originated from the high-resolution color image and low-resolution depth map respectively, pixels in up-sampled depth maps can be classified into four categories: edge points, edge-neighbor points, texture points and smooth points. First, joint bilateral up-sampling (JBU) method is used to generate an initial up-sampling depth image. Then, for each pixel category, different refinement methods are employed to modify the initial up-sampling depth image. Experimental results show that the proposed algorithm can reduce the blurring artifact with lower bad pixel rate (BPR).

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.945-949
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• 1988

In this paper, collision avoidance of two robots working in a common workspace is described. The workspace for a two robot system is defined and classified. JCM (Joint Constraint Map) is designed which shows the region of joint values that must be avoided for collision free motion, and application of the JCM is studied.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.120-132
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• 2019

As a key infrastructure for positioning autonomous vehicles, HD maps are making efforts to equip autonomous vehicles and connect them with services worldwide. Global companies like Here and TomTom have contracted an agreement with three German automobile companies(BMW, Audi, Daimler) by establishing systems including from the production of HD maps to loading autonomous vehicles. Japan has organized a DMP(Dynamic Map Platform) by collaborating public and private section and performing establishment of HD map on private section-oriented. Korean companies related with autonomous vehicles are also cooperating with various companies such as vehicles, sensors and maps. But public and private sections are establishing HD maps respectively. Accordingly, Ministry of Land, Infrastructure and Transport implemented and signed memorandum for private and public cooperation in April 2019, Joint establishment council of HD map has launched in August 2019. This study performed domestic and foreign trend analysis about HD map and interviewed to related companies. And analyzed solutions for interactive cooperation of private and public section in HD map industry, purposed step-by-step strategy for operation and operation plan for joint establishment council of HD map.

• The korean journal of orthodontics
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• v.50 no.2
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• pp.86-97
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• 2020

Objective: To propose a three-dimensional (3D) method for evaluating temporomandibular joint (TMJ) changes during Twin-block treatment. Methods: Seventeen patients with Class II division 1 malocclusion treated using Twin-block and nine untreated patients with a similar malocclusion were included in this research. We collected their cone beam computed tomography (CBCT) data from before and 8 months after treatment. Segmentations were constructed using ITK-SNAP. Condylar volume and superficial area were measured using 3D Slicer. The 3D landmarks were identified on CBCT images by using Dolphin software to assess the condylar positional relationship. 3D models of the mandible and glenoid fossa of the patients were constructed and registered via voxel-based superimposition using 3D Slicer. Thereafter, skeletal changes could be visualized using 3DMeshMetric in any direction of the superimposition on a color-coded map. All the superimpositions were measured using the same scale on the distance color-coded map, in which red color represents overgrowth and blue color represents resorption. Results: Significant differences were observed in condylar volume, superficial area, and condylar position in both groups after 8 months. Compared with the control group (CG), the Twin-block group exhibited more obvious condyle-fossa modifications and joint positional changes. Moreover, on the color-coded map, more obvious condyle-fossa modifications could be observed in the posterior and superior directions in the Twin-block group than in the CG. Conclusions: We successfully established a 3D method for measuring and evaluating TMJ changes caused by Twin-block treatment. The treatment produced a larger condylar size and caused condylar positional changes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.37-39
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• 2012

최근 ToF(Time-of-Flight) 방식의 깊이 센서 카메라가 깊이 영상 획득에 많이 사용되고 있다. 그러나 ToF 깊이 카메라가 제공하는 깊이 영상은 센서의 물리적 한계로 인해 잡음이 존재한다. 따라서 고품질의 깊이 영상을 얻기 위해서는 깊이 영상의 잡음을 제거해 주는 것이 필수적이다. 일반적으로 깊이 영상의 잡음 제거에는 joint bilateral filter 를 사용한다. Joint bilateral filter 는 기준 화소와 그 주변 화소의 색상 영상의 밝기 차이값과 화소간 거리값에 각각 가우시안 함수를 적용하여 joint histogram 을 생성하고 그 평균값을 기준 화소의 깊이값으로 채운다. 하지만 이 과정에서 깊이 영상의 경계 영역에서 흐려짐 현상이 발생한다. 경계영역에 발생한 흐려짐 현상은 최종적인 3D 입체 콘텐츠의 품질을 저하시킨다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 joint histogram 의 최고점을 찾아 기준 화소의 깊이값을 채우는 기법을 제안한다. 최고점 탐색을 통해 기존 기법의 평균값을 통해 생기는 흐려짐 현상을 줄이고 깊이 영상의 경계를 보존하면서 잡음을 제거하였다. 실험을 통하여 제안하는 기법의 우수성을 확인하였다.

• Journal of Information Processing Systems
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• v.15 no.4
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• pp.785-796
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• 2019

Due to the view point, illumination, personal gait and other background situation, person re-identification across cameras has been a challenging task in video surveillance area. In order to address the problem, a novel method called Joint Bayesian across different cameras for person re-identification (JBR) is proposed. Motivated by the superior measurement ability of Joint Bayesian, a set of Joint Bayesian matrices is obtained by learning with different camera pairs. With the global Joint Bayesian matrix, the proposed method combines the characteristics of multi-camera shooting and person re-identification. Then this method can improve the calculation precision of the similarity between two individuals by learning the transition between two cameras. For investigating the proposed method, it is implemented on two compare large-scale re-ID datasets, the Market-1501 and DukeMTMC-reID. The RANK-1 accuracy significantly increases about 3% and 4%, and the maximum a posterior (MAP) improves about 1% and 4%, respectively.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1770-1781
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• 1989

Two robots working in a common workspace may collide with each other. In this paper, a collision-free motion planning algorithm using view time concept is proposed to detect and avoid collision before robot motion. Collision may occur not only at the robot end effector but also at robot links. To detect and avoid potential collisions, the trajectory of the first robot is sampled periodically at every view time and the region in Cartesian space swept by the first robot is viewed as an obstacle during a single sampling period. The forbidden region in the joint constraint map (JCM). The JCM's are obtained in this way at every view time. An algorithm is established for collision-free motion planning of the two robot system from the sequence of JCM's and it is verified by simulations.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.4
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• pp.105-117
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• 1998

In this paper, the general formula of disparity estimation based on Bayesian Maximum A Posteriori (MAP) algorithm is derived and implemented with simplified probabilistic models. The probabilistic models are independence and similarity among the neighboring disparities in the configuration.The formula is the generalized probabilistic diffusion equation based on Bayesian model, and can be implemented into the some different forms corresponding to the probabilistic models in the disparity neighborhood system or configuration. And, we proposed new probabilistic models in order to simplify the joint probability distribution of disparities in the configuration. According to the experimental results, the proposed algorithm outperformed the other ones, such as sum of swuared difference(SSD) based algorithm and Scharstein's method. We canconclude that the derived formular generalizes the probabilistic diffusion based on Bayesian MAP algorithm for disparity estimation, and the propsoed probabilistic models are reasonable and approximate the pure joint probability distribution very well with decreasing the computations to 0.01% of the generalized formula.

• Investigative Magnetic Resonance Imaging
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• v.15 no.1
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• pp.57-66
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• 2011

Purpose : A new inhomogeneity correction method based on two-point Dixon sequence is proposed to obtain water and fat images at 0.35T, low field magnetic resonance imaging (MRI) system. Materials and Methods : Joint phase-magnitude density function (JPMF) is obtained from the in-phase and out-of-phase images by the two-point Dixon method. The range of the water signal is adjusted from the JPMF, and 3D inhomogeneity map is obtained from the phase of corresponding water volume. The 3D inhomogeneity map is used to correct the inhomogeneity field iteratively. Results : The proposed water-fat imaging method was successfully applied to various organs. The proposed 3D inhomogeneity correction algorithm provides good performances in overall multi-slice images. Conclusion : The proposed water-fat separation method using JPMF is robust to field inhomogeneity. Three dimensional inhomogeneity map and the iterative inhomogeneity correction algorithm improve water and fat imaging substantially.