• Journal of the HCI Society of Korea
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• v.9 no.2
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• pp.13-21
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• 2014

Jump-rope is a simple and effective exercise, but its intensive exercise load and monotonous pattern make it difficult to perform consistent workout. On the other hand, jumping rope accompanies large amount of kinetic energy which can be converted into electrical energy. In this study, we designed and implemented a self-powered jump-rope which can support the low-power embedded Bluetooth system inside it. The embedded system wirelessly transmits the acceleration data measured during jumping-rope exercise to a smartphone. We also developed a smartphone app which can count the number of jumps and provide real-time feedback with sound and animated graphic effects in a game context. Pilot test using the prototype smart jump-rope verified that it can be useful to motivation for the jump-rope exercise and make the exercise more effective by providing users with precise information about their exercise. We expect that the developed self-powered jump-rope will change the exercise from an intensive physical activity into electricity-generating fun experience combined with smartphone game, which maximize the benefit of the consistent jump-rope exercise.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.143-149
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• 2011

This paper presents a novel camera tracking method based on model with multiple planes. The proposed algorithm detects QR code that is one of the most popular types of two-dimensional barcodes. A 3D model is imported from the detected QR code for augmented reality application. Based on the geometric property of the model, the vertices are detected and tracked using optical flow. A clipping algorithm is applied to identify each plane from model surfaces. The proposed method estimates the homography from coplanar feature correspondences, which is used to obtain the initial camera motion parameters. After deriving a linear equation from many feature points on the model and their 3D information, we employ DLT(Direct Linear Transform) to compute camera information. In the final step, the error of camera poses in every frame are minimized with local Bundle Adjustment algorithm in real-time.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1333-1341
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• 2009

Tactical path-finding in computer games is path-finding where a path is selected by considering not only basic elements such as the shortest distance or the minimum time spend but also tactical information of surroundings when deciding character's moving trajectory. One way to include tactical information in path-finding is to represent a heuristic function as a sum of tactical quality multiplied by a weighting factor which is.. determined based on the degree of its importance. The choice of weighting factors for tactics is very important because it controls search performance and the characteristic of paths found. In this paper. we propose a method for improving a heuristic function by adjusting weights based on the difference between paths on examples given by a level designer and paths found during the search process based on the CUITent weighting factors. The proposed method includes the search algorithm modified to detect search errors and learn heuristics and the perceptron-like weight updating formular. Through simulations it is demonstrated how different paths found by tactical path-finding are from those by traditional path-finding. We analyze the factors that affect the performance of learning and show the example applied to the real game environments.

• Journal of Korea Game Society
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• v.13 no.3
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• pp.85-94
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• 2013

In this paper, we propose a scheme to reduce the number of shadow tests conducted during rendering of ray tracing. The shadow test is a very important process in ray tracing to generate photo-realistic images. In the rendering phase, the ray tracer determines whether to cull the shadow test based on information calculated from a shadow test conducted on the kd-tree in the preprocessing phase. In conventional rendering process, the proposed method can be used with little modification. The proposed method is suitable for a static scene, in which the geometry and light source does not change in the same manner as it does in the conventional method. The validity of the proposed scheme is verified and its performance is evaluated during cycle-accurate simulation. Through experiment results, we found that we could reduce up to 17% of the shadow test.

• Journal of Korea Game Society
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• v.10 no.4
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• pp.63-71
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• 2010

In this paper, we propose a boundary based marker binary coding method for augmented reality games, which enables the marker-area to be binary coded well in any lighting environments. First, it detects the boundary after transforming an original marker image to a gray scale image, and it executes 4 way pixel extensions for all boundary pixels in order to make the boundary to closed area. Next, for all boundary pixels it compares the brightness of right and left ones of each pixel and allocates black for the lower side and white for the higher side by filling inside area thru the seeded region growing. Experimental results showed that our proposed method produces a good binary marker image recognizable in various light environments. In addition, it showed the possibility of real-time calculation by considering the result of operation speed which is 51 fps for VGA image.

• Journal of Korea Game Society
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• v.11 no.1
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• pp.131-138
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• 2011

Recently in terrain rendeing, most researches introduce mipmap-based out-of-core methods for handling large sized DEM data which does not fit in main memory of general computer. However, mipmap-based LOD(level-of-detail) methods occur geometric errors which appear in data simplifying the higher LOD level. These geometric errors cause geometric popping effects where LOD level changes when viewpoint moves. In this paper, we propose vertex cohesion map for reducing geometric error. In preprocessing step, we generate vertex cohesion map, which is a texture that stores the vectors. By these vectors, each vertex will be cohered into the position in which the difference of gradient value is bigger than others. Therefore in terrain rendering, using vertex cohesion map can dramatically reduce the geometry popping effects rather than using mipmap.

• Journal of KIISE:Software and Applications
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• v.27 no.7
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• pp.712-722
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• 2000

In this paper, we suggest and test a classification technique of offence pattern from group formation to automatically index highlights of soccer games. A BP (Back-propagation) neural nets technique was applied to the information of the position of both the player and the ball on a ground, and the distance between the player and the ball to identify the group formation in space and time. The real soccer game scenes including '98 France World Cup were used to extract 297 video clips of various types of offence patterns; Left Running 60, Right Running 74, Center Running 72, Corner-kick 39 and Free-kick 52. The results are as follows: Left Running comes to 91.7%, Right Running 100%. Center Running 87.5%, Corner-kick 97.4% and Free-kick 75%, and these showed quite a satisfactory rate of recognition.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.147-156
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• 2010

In this paper, we propose 3D cloud animation by cloud modeling method of 2D images retrieved from a meteorological satellite. First, on the satellite images, we locate numerous control points to perform thin-plate spline warping analysis between consecutive frames for the modeling of cloud motion. In addition, the spectrum channels of visible and infrared wavelengths are used to determine the amount and altitude of clouds for 3D cloud image reconstruction. Pre-integrated volume rendering method is used to achieve seamless inter-laminar shades in real-time using small number of slices of the volume data. The proposed method could successfully construct continuously moving 3D clouds from 2D satellite images at an acceptable speed and image quality.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.183-189
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• 2008

The next-generation war game simulators need a technique that reuses resources disperse on the web, and reorganizes federates on the fly based on the various events in real time. So far, HLA-based federates limit their interoperability to military networks, and in syntax-level. Web services techniques are widely used in enterprise applications and provide many proven practices to extend interoperability between WAN resources in semantic level. Two problems are met in order to utilize web services into war-game simulator : 1) How to achieve semantic-level interoperability between federates disperse on WAN, 2) How to interoperate web-based federates and RTI-based federates. In this paper, we provide solutions to the problems and highlight advantages using web-based federates with an example of ASuW(Anti-Surface Warfare).

• Journal of Korea Game Society
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• v.15 no.4
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• pp.121-132
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• 2015

This study suggests a design for an analytical software program and method for multitasking e-sports viewing through the web using an eye tracking device. To fulfill this task, we designed a Window of Interest (WOI) to measure and record visually on a screen wherever numerous multitasking activities occur. In addition, we developed an OBS (Opensource Broadcaster Software) plug-in that records and streams participant viewing behavior patterns in real time. The purpose of this study is as follows. First, unlike existing tools that limit web interface recording to still images, the developed tool can record dynamically via media such as videos. Second, when several windows are processed on a screen, the tool can accurately record the gaze positions of the participants. Lastly, the tool can enhance the objective validity of the data as it can be implemented in natural situations. Therefore, this study can trace natural viewing patterns and behavior as we do not create artificial experimental environments and stimuli.