• Steel and Composite Structures
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• v.28 no.2
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• pp.179-194
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• 2018

Reliable and accurate method of computationally aided design processes of advanced thin walled structures in automotive industries are much essential for the efficient usage of smart materials, that possess higher energy absorption in dynamic compression loading. In this paper, most versatile components i.e., thin walled crash tubes with different geometrical profiles are introduced in view of mitigating the impact of varying cross section in crash behavior and energy absorption characteristics. Apart from the geometrical parameters such as length, diameter and thickness, the non-dimensionalized parameters of average forces which control the plastic bending moment for varying thickness has explored in view of quantifying its impact on the crashworthiness of the structure. The explicit finite element code ABAQUS is utilized to conduct the numerical studies to examine the effect of parametric modifications in crash behavior and energy absorption. Also the simulation results are experimentally validated. It is evident that the circular cross-sectional tubes are preferable as high collision impact shock absorbers due to their ability in withstanding axial and oblique impact loads effectively. Furthermore, the specific energy absorption (SEA), crash force efficiency (CFE), plastic bending moment, peak force responses and its impact for optimally tailoring a design to cater the crashworthiness requirements are investigated. The primary outcome of the study is to provide sufficient information on circular tubes for the use of energy absorbers where impact oblique loading is expected.

• ETRI Journal
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• v.36 no.4
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• pp.662-672
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• 2014

Human action recognition is used in areas such as surveillance, entertainment, and healthcare. This paper proposes a system to recognize both single and continuous human actions from monocular video sequences, based on 3D human modeling and cyclic hidden Markov models (CHMMs). First, for each frame in a monocular video sequence, the 3D coordinates of joints belonging to a human object, through actions of multiple cycles, are extracted using 3D human modeling techniques. The 3D coordinates are then converted into a set of geometrical relational features (GRFs) for dimensionality reduction and discrimination increase. For further dimensionality reduction, k-means clustering is applied to the GRFs to generate clustered feature vectors. These vectors are used to train CHMMs separately for different types of actions, based on the Baum-Welch re-estimation algorithm. For recognition of continuous actions that are concatenated from several distinct types of actions, a designed graphical model is used to systematically concatenate different separately trained CHMMs. The experimental results show the effective performance of our proposed system in both single and continuous action recognition problems.

• Journal of KIBIM
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• v.11 no.4
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• pp.42-52
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• 2021

Paneling building facades is one of the essential procedures in building construction. Traditionally, it has been an easy task of simply projecting paneling patterns drawn in drawing boards onto 3d building facades. However, as many organic or curved building shapes are designed and constructed in modern architectural practices, the traditional one-to-one projection is becoming obsolete for the building types of the kind. That is primarily because of the geometrical discrepancies between 2d drawing boards and 3d curved building surfaces. In addition, curved compound surfaces are often utilized to accommodate the complicated spatial programs, building codes, and zoning regulations or to achieve harmonious geometrical relationships with neighboring buildings in highly developed urban contexts. The use of the compound surface apparently makes the traditional paneling pattern projection more challenging. Various mapping technics have been introduced to deal with the inabilities of the projection methods for curved facades. The mapping methods translate geometries on a 2d surface into a 3d building façade at the same topological locations rather than relying on Euclidean or Affine projection. However, due to the intrinsic differences of the planar 2d and curved 3d surfaces, the mapping often comes with noticeable distortions of the paneling patterns. Thus, this paper proposes a practical method of drawing paneling patterns directly on a curved compound surface utilizing Geodesic, which is faithful to any curved surface, to minimize unnecessary distortions.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.1
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• pp.43-50
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• 2009

Geometry calculation Using Abdominal internal organ image from traditional laparoscopy or robotic surgery system we can make depth informations through measured 3D structure informations is very helpful to doctors, depth information is mare useful then others that use traditional laparoscopy or robotic surgery system to many doctors. however, traditional method are incomplete. less experienced doctors make much mare prohability of mistake. Hence, 3D information of organ is very helpful to the less experienced doctors. it will be greate role of reducing medical accidents and surgical time. We can get 3D informations using geometrical calculation method in robotic surgical system. also suggested method is needed in traditional surgical method without the need to create a new system, finally, We can get 3D information from traditional system without any new system, it take advantage in cost and create high efficiency. mare information will provided to many doctors.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1591-1600
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• 2007

Camera position information from 2D face image is very important for that make the virtual 3D face model synchronize to the real face at view point, and it is also very important for any other uses such as: human computer interface (face mouth), automatic camera control etc. We present an algorithm to detect human face region and mouth, based on special color features of face and mouth in $YC_bC_r$ color space. The algorithm constructs a mouth feature image based on $C_b\;and\;C_r$ values, and use pattern method to detect the mouth position. And then we use the geometrical relationship between mouth position information and face side boundary information to determine the camera position. Experimental results demonstrate the validity of the proposed algorithm and the Correct Determination Rate is accredited for applying it into practice.

• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.123-143
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• 2004

Nowadays, insufficient parking lots give rise to a serious problem. Cars are increased in geometrical progression, but parking lots that takes in cars are relatively limited. Often we spend a lot of time to look for a parking lot because of limited parking lot. To solve this problem, we can use real time parking lot information system provided from mobile vehicles. In this paper, we will tell you how to deliver the parking lot information in real time by construction wireless network environment to be provided real time information and making XML data that is easy to share and to exchange data between applications.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.263-266
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• 2000

An elliptical ogive head for a generic missile is proposed to reduce its detectable probability from a ground defense radar. Numerical RCS results of a generic missile with an elliptical ogive head are evaluated using the GTD/UTD (Geometrical Theory of Diffraction/Uniform GTD). The results are compared with those of a cylindrical ogive head. In the sense of aerodynamics, the Performance evaluation of an elliptical ogive head for a generic missile should be followed.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.820-823
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• 1996

In contrast to parts of relatively simple shapes, it is important to match their cross-sectional shapes during mating parts of complicated shapes. It requires the 2.pi. information along their matching boundary to figure out their relative geometrical shapes. In this paper, we propose a method measuring a misalignment at the interface during mating parts with the complicated shapes by using the omnidirectional image sensing system(OLSSA). Also we carried out experiments in order to prove the method, and the results show the feasibility.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.173-176
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• 1998

The surface wave launcher from the dielectric coated coaxial cable to dielectric slab is investigated. FDTD method using local subcell and contour-path model is applied to determine the fine geometrical features. The reflection coefficient in coaxial cable region is found using extract algorithm. In this paper, two structures are presented as coaxial slot surface wave launcher. One structure has a vertical launching angle, and the other has an arbitrary launching angle. The numerical results show that a certain launching angle is minimized the reflection coefficient.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1850-1856
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• 1989

For determining motion/structure of a 3-D rigid object from point correspondences over two perspective views, a linear algorithm was developed in Refs. 3 and 4. This algorithm fails when the 3-D points under observation satisfy certain geometrical constraints, as demonstrated in Refs. 7 and 8. In the present paper, we show that the linear algorithm can be resurrected in these degenerate cases by adding additional lower order polynomial constraints to original equations.