• 한국멀티미디어학회논문지
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• 제15권6호
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• pp.827-836
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• 2012

키넥트의 성공적인 등장 이후 이 센서를 이용하여 사용자의 아바타에 해당하는 3차원 캐릭터의 움직임을 제어하는 많은 인터액티브 콘텐츠가 제작되었다. 하지만, 키넥트의 특성 상 사용자는 키넥트를 정면으로 바라보아야 하며, 모션 또한 제자리에서 수행할 수 있는 동작 정도만으로 국한되었다. 이 단점은 게임에서 가장 중요한 요구기능 중 하나인 가상공간 내비게이션을 수행하지 못하게 하는 근본적인 이유가 되었다. 본 논문은 이와 같은 단점을 해결하기 위한 새로운 방법을 제안한다. 두 단계로 이루어진 본 방법은 첫 번째 단계로서 사용자의 내비게이션 의도를 파악하기 위해 제자리 걷기 동작 제스처인식을 수행한다. 내비게이션 의도가 파악되면, 다음 단계에 현재 제자리 걷기동작을 상체와 하체 모션으로 자동으로 분리한 후, 미리 입력 받은 하체모션캡처 데이터를 현재 캐릭터 속도를 반영하여 수정한 뒤 분리된 원래 하체모션과 자연스럽게 교체한다. 본 논문에서 제안된 알고리즘을 이용하면, 키넥트 센서를 통해 사용자의 상체 모션을 그대로 반영함과 동시에 모션캡처 데이터를 이용하여 하체 동작을 실제 걷는 동작으로 바꾸어주기 때문에 사용자가 조정하는 3차원 캐릭터는 가상공간을 자연스럽게 내비게이션할 수 있다.

• IUGG한국위원회:학술대회논문집
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• IUGG한국위원회 2003년도 정기총회 및 학술발표회
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• pp.18-18
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• 2003

Three-dimensional finite-difference simulation of earthquake ground motion is performed using a locally variable time-step (LVTS) scheme matching with discontinuous grids. Discontinuous grids in three directions and extension of the discontinuous grids' boundary to the free-surface in the LVTS scheme minimize the cost of both the computational memory and the CPU time for models like the localized sedimentary basin. A simplified model of sedimentary basin is dealt to show the feasibility and efficiency of the LVTS scheme. The basin parameters are examined to understand the main characteristics on ground-motion response in the basin. The results show that the seismic energy is concentrated on a marginal area of the basin far from the source. This focusing effect is mainly due to the constructive interference of the direct S-wave with the basin-edge induced surface waves. The ground-motion amplification over the deepest part of the basin is relatively lower than that above the shallow basin edge. Therefore the ground-motion amplification may be more related to the source azimuth or the direction of the incident waves into the basin rather than the depth of it.

• 수산해양기술연구
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• 제28권3호
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• pp.252-261
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• 1992

The accuracy of the position fixing with telemetry techniques depends in general on the accuracy of the location of the receiving point(hydrophone). To increase the accuracy of the coordinates of four hydrophones suspended down at both sides of the vessel anchored, each hydrophone motion is compensated using a depth pinger mounted on the seabed of 30m depth. The pinger location is calculated with a hyperbolic method. Using this technique so called hydrophone coordinates calibration, the movement of the Remotely Operated Vehicle(ROV), which has the same type of pinger mentioned above could be tracked down more accurately. Under the maximum variation ranges of a hydrophone of 5.2m in athwartships, 3.2m in alongship, and about 0.2m/s of the moving velocity in both directions, the ROV track with calibration is more close to the reality than that without calibration Tow depth pingers of same frequency can be distinguished by the use of three factors; The pulse period, the phase and the pulse period variation allowed in acquisition of the pinger as far as its pulse period is varied in smooth.

• Journal of the Optical Society of Korea
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• 제16권4호
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• pp.381-385
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• 2012

In this paper, we present a novel integral imaging pickup method. We extract each pixel's actual depth data from a real object's surface using a depth camera, then generate elemental images based on the depth map. Since the proposed method generates elemental images without a lens array, it has simplified the pickup process and overcome some disadvantages caused by a conventional optical pickup process using a lens array. As a result, we can display a three-dimensional (3D) image in integral imaging. To show the usefulness of the proposed method, an experiment is presented. Though the pickup process has been simplified in the proposed method, the experimental results reveal that it can also display a full motion parallax image the same as the image reconstructed by the conventional method. In addition, if we improve calculation speed, it will be useful in a real-time integral imaging display system.

• 한국의류학회지
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• 제32권4호
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• pp.553-561
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• 2008

The purpose of this research was to analyze the relationship between the ease of crotch depth and the mobility of leg movement. Ten Korean men were participated as subjects and 0. 3, 6cm of crotch ease were inserted for test clothes. To analyze objectively, range-of-motion of four selected movements was measured by Leighton flexometer and goniometer. Also. wearer acceptability rating was measured for subjectively investigation. Anova and Duncan's range tests were used for statistical analysis. According to the results, 3cm of crotch ease was most comfortable. The mobility of test clothes with 3cm crotch ease was improved largely in every test movement(16.2% and 16.6% in segittal plane, and 6.1% and 6.2% in frontal motion).

• 로봇학회논문지
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• 제3권3호
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• pp.212-218
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• 2008

Collision avoidance is a fundamental and important task of an autonomous mobile robot for safe navigation in real environments with high uncertainty. Obstacles are classified into static and dynamic obstacles. It is difficult to avoid dynamic obstacles because the positions of dynamic obstacles are likely to change at any time. This paper proposes a scheme for vision-based avoidance of dynamic obstacles. This approach extracts object candidates that can be considered moving objects based on the labeling algorithm using depth information. Then it detects moving objects among object candidates using motion vectors. In case the motion vectors are not extracted, it can still detect the moving objects stably through their color information. A robot avoids the dynamic obstacle using the dynamic window approach (DWA) with the object path estimated from the information of the detected obstacles. The DWA is a well known technique for reactive collision avoidance. This paper also proposes an algorithm which autonomously registers the obstacle color. Therefore, a robot can navigate more safely and efficiently with the proposed scheme.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1006-1012
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• 2003

Recently, floating offshore structure is studied as one of the effective utilization of the ocean space. And floating structure are now being considered for various applications such as floating airports, offshore cities and so on. The motion analysis of the fishing spot of floating offshore structure as it receives regular wave is studied. The finite element method is used in the analysis of structural section of this structure. And the analysis is carried out using the boundary element method in the fluid division. In order to know the characteristics of the motion of the floating fishing spot structures, effects of wavelength, water depth, and wave direction on dynamic response of the floating structure are studied by use of numerical calculation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3924-3940
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• 2020

Dynamic hand gesture recognition(d-HGR) plays an important role in human-computer interaction(HCI) system. With the growth of hand-pose estimation as well as 3D depth sensors, depth, and the hand-skeleton dataset is proposed to bring much research in depth and 3D hand skeleton approaches. However, it is still a challenging problem due to the low resolution, higher complexity, and self-occlusion. In this paper, we propose a hand-shape feature extraction(HSFE) network to produce robust hand-shapes. We build a hand-shape model, and hand-skeleton based on LSTM to exploit the temporal information from hand-shape and motion changes. Fusion between two models brings the best accuracy in dynamic hand gesture (DHG) dataset.

• 대한조선학회논문집
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• 제47권3호
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• pp.328-341
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• 2010

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is designed with the similar concept of UUV called Manta Test Vehicle(MTV), which was originally built by the Naval Undersea Warfare Center, USA(Lisiewicz and French 2000, Sirmalis et al. 2001, U.S. Navy 2004). The present study deals with evaluation of extreme motion of MUUTV at large attack angles. Extreme motion contains, for example, rising and depth change due to operation of hovering thrusters attached to MUUTV, lateral motion due to ocean current applied to MUUTV at low advance velocity, and so on. Numerical simulation technique has been utilized. The previous mathematical model on manoeuvring motion of MUUTV(Bae et al. 2009a) is basically adopted. Based on the results of present model experiment on extreme motion, the mathematical model is revised and supplemented in order to describe extreme motion. The hydrodynamic derivatives related to extreme motion are obtained from present model experiment and the other derivatives are referred to previous work(Bae et al. 2009a).

• 대한조선학회지
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• 제19권4호
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• pp.39-45
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• 1982

A floating rig, which has been used to develop the ocean resources has a common characteristics with the catamaran ship that it is composed of the two simple hulls. So the motion responses of the floating rig can be predicted theoretically with the aid of the strip method as those of the catamaran. And for the strip method, the two-dimensional hydrodynamic coefficients are the most important inputs to predict the results accurately. In this report, a theoretical method is proposed for calculating two-dimensional hydrodynamic forces and moments acting upon arbitrary shaped twin-hull cylinders, which are forced to make a heaving, swaying and rolling oscillation about their mean position on the free surface of a finite depth water. The theoretical results by making use of the singularity distribution method are presented. The accuracy of the coefficients was confirmed to be reasonable by the comparison with the Ohkusu's results for two circular cylinders in an infinite depth water. The depth effects on two-dimensional hydrodynamic coefficients for two circular cylinders are also checked. In some range of wave numbers, large differences in the behavior of hydrodynamic coefficients between for a finite depth and for an infinite depth are shown.