• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.196-198
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• 2006

Shader architecture is one of the fastest growing fields in the ever advancing 3D graphics, and massive amounts of Ideas and technologies are being introduced to the market continuously. In this paper, we present a flexible cycle-accurate simulation environment to accelerate and alleviate the process of developing and verifying these ideas and technologies. Combination of 3D graphics API and hardware simulator allows OpenGL applications to be emulated off-the-shelf for a given shader micro-architecture. Easily modified parameters allow the simulation environment to be tailored to specific demands or requirements.

• IE interfaces
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• v.13 no.2
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• pp.157-165
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• 2000

In this paper, an efficient method is proposed to place the cooling lines(CLS) and ejector pins(EPS) of mold design. The other components of mold, except CLS and EPS, can be generated automatically by batch processing. But the placements and sizes of CLS and EPS depend on the shapes of a part, so that the design works of CLS and EPS should be processed interactively. Using the pre-defined reference points, the positions of CLS and EPS can be determined interactively. By the proposed method, the interference occurred during placing CLS and EPS can be avoided, and the proper lengths of them can be calculated automatically. The information of the positions and lengths are stored in BOM database for generating a machining data. The proposed method is implemented with Unigraphics API functions and C language, tested on Unigraphics V15.

• Annual Conference of KIPS
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• 2001.04a
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• pp.349-352
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• 2001

웹 기반 협동설계시스템은 인터넷망과 웹브라우저를 이용하여 공유된 가상 공간에서 협동작업이 이루어지도록 한다. 이때 공유 오브젝트는 3D 도형이 되며, 사용자가 임의의 오브젝트를 선택하여 조작하기 위하여 picking이 효과적으로 이루어져야 한다. 본 논문에서는 오브젝트의 picking이 마우스 포인터에서의 ray와 오브젝트간에 intersection을 계산하는 방법 외에 Java 3D API를 이용하여 scene graph의 노드에 picking 속성을 주는 방법, bounds를 설정하는 방법, picking test의 범위를 한정하는 방법을 사용하여 computation의 부담을 줄이고 효과적인 picking이 이루어지도록 한다.

• 전자공학회논문지 IE
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• v.44 no.4
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• pp.11-18
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• 2007

Concept of URC does "with me wherever when, and the robot" which provides necessary service to me can be simply defined. This paper uses URC technology and various robots are implemented with a design. That is, we are going to implement that a user controls a virtual robot by communication between URC server with a design. We used an intelligent robot simulation tool, and a developer was easy, and it was intelligent, and we were connected to active URC server, and modeling did a system for simulation to be able to do an URC robot usefully. It was connected to an URC system and various robots and environments were composed with 3D, and, in this paper, a design and implementation did an intelligent robot simulation system so that it was possible by various contents development through simulation. The URC communication protocol and the URC server were based on a Planet v.1.2 ; Network Protocol, CAMUS(Context-Aware Middleware for URC Systems); URC Server, SAM(Service Agent Manager) v.1.2 ; Service API module developed in Electronics & Telecommunications Research Institute (ETRI).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.4
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• pp.21-28
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• 2024

Nowadays, based on the 4th Industrial Revolution, by using the CHATGPT function and 3D virtual reality technology, anyone can easily open a virtual environment WEB-based, smart tourism OPEN source and travel destination without having to directly visit the travel location in the real world. Using the API function, it provides the convenience of virtual tourism. However, this function does not work if the travel transportation system is suddenly changed due to sudden bad weather, travel operation information cannot be checked in real time, and due to a lack of flight cancellation information and passenger ship operation information, it cannot be used until the plane or ferry departs normally. A very inconvenient problem arises where you have to wait a long time in the waiting room. Therefore, in this paper, in order to solve this problem, automatic duty-free product information and automatic product payment functions were added even when passenger ship cancellations and operation information suddenly occur due to bad weather and multiple products are purchased during the trip. In addition, the computer simulation experiment was conducted on a WEB basis so that anyone can conveniently travel smartly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.912-920
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• 2002

As computer systems and communication technologies develop rapidly, CSCW(Computer Supported Collaborative Work) system appears nowadays, through which it is available to work on virtual space without any restriction of time and place. Most of CWCS systems depend on a special network and groupware. The systems of graphics and CAD are not so many because they are specified by hardware and application software. We propose a Web-based collaborative CAD system which is independent from any platforms, and develop a 3D solid modeler in the system. This system can be worked in the environment of Client/Server architecture. Clients connect to the design server through Java applet on WWW. The server is implemented by Java application.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.129-151
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• 2022

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of piles when the adjacent tunnelling passes underneath grouped piles with a reinforced pile cap. In the current study, the numerical analysis studied the computed results regarding the ground reinforcement condition between the tunnel and pile foundation. In addition, several key issues, such as the pile settlements, the axial pile forces, the shear stresses and the relative displacements have been thoroughly analysed, and the IoT platform based preliminary design guidelines were also presented. The pile head settlements of the nearest pile from the tunnel without the ground reinforcement increased by about 70% compared to the farthest pile from the tunnel with the maximum level of reinforcement. The quality management factor data of the piles were provided as API (Application Programming Interface) of various forms by the collection and refinement. Hence it has been shown that it would be important to provide the appropriate API by defining the each of data flow process when the data were created. The behaviour of the grouped piles with the pile cap, depending on the amount of ground reinforcement, has been extensively analysed, and the IoT platform regarding the quality management of piles has been suggested.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.11-23
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• 2022

The response of pile foundations under lateral loads are usually analyzed using beam-on-nonlinear-Winkler-foundation (BNWF) model framework employing various forms of empirically derived p-y curves and p-multipliers. In practice, the p-y curve presented by the American Petroleum Institute (API) is most often utilized for piles in granular soils, although its shortcomings are recognized. The objective of this study is to evaluate the performance of the BNWF model and to quantify the error in the estimated pile response compared to a rigorous numerical model. BNWF analyses are performed using three sets of p-y curves to evaluate reliability of the procedure. The BNWF model outputs are compared with results of 3D nonlinear finite element (FE) analysis, which are validated via field load test measurements. The BNWF model using API p-y curve produces higher load-displacement curve and peak bending moment compared with the results of the FE model, because empirical p-y curve overestimates the stiffness and underestimates ultimate resistance up to a depth equivalent to four times the pile diameter. The BNWF model overestimates the peak bending moment by approximately 20-30% using both the API and Reese curves. The p-multipliers are revealed to be sensitive on the p-y curve used as input. These results highlight a need to develop updated p-y curves and p-multipliers for improved prediction of the pile response under lateral loading.

• Structural Engineering and Mechanics
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• v.81 no.5
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• pp.565-574
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• 2022

The infrastructures such as offshore, bridges, power plant, oil and gas piping and aircraft operate in a harsh environment during their service life. Structural integrity of engineering components used in these industries is paramount for the reliability and economics of operation. Two regression models based on the concept of Gaussian process regression (GPR) and Minimax probability machine regression (MPMR) were developed to predict stress intensity factor range (𝚫K). Both GPR and MPMR are in the frame work of probability distribution. Models were developed by using the fatigue crack growth data in MATLAB by appropriately modifying the tools. Fatigue crack growth experiments were carried out on Eccentrically-loaded Single Edge notch Tension (ESE(T)) specimens made of API 5L X65 Grade steel in inert and corrosive environments (2.0% and 3.5% NaCl). The experiments were carried out under constant amplitude cyclic loading with a stress ratio of 0.1 and 5.0 Hz frequency (inert environment), 0.5 Hz frequency (corrosive environment). Crack growth rate (da/dN) and stress intensity factor range (𝚫K) values were evaluated at incremental values of loading cycle and crack length. About 70 to 75% of the data has been used for training and the remaining for validation of the models. It is observed that the predicted SIF range is in good agreement with the corresponding experimental observations. Further, the performance of the models was assessed with several statistical parameters, namely, Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Coefficient of Efficiency (E), Root Mean Square Error to Observation's Standard Deviation Ratio (RSR), Normalized Mean Bias Error (NMBE), Performance Index (ρ) and Variance Account Factor (VAF).

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.581-586
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• 2017

This paper proposes a GPU based water surface animation and rendering technique for interactive applications such as games. On the water surface, a lot of physical phenomenon occurs including reflection and refraction depending on the viewing direction. When we represent the water surface, not only showing them in real time, but also make them adjusted automatically. In our implementation, we are able to capture the reflection and refraction through render-to-texture technique and then modify the texture coordinates for applying separate DU/DV map. Also, we make the amount of ratio between reflection and refraction change automatically based on Fresnel formula. All proposed method are implemented using OpenGL 3D graphics API.