• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.05a
• /
• pp.588-589
• /
• 2023

챗 GPT 는 음성 혹은 문자로 사람과 대화할 수 있는 컴퓨터 프로그램인 챗봇(ChatBot) 중 하나이다. 최근 챗 GPT 의 사용자가 급격히 증가하면서 다양한 문제점과 한계가 발견되고 있다. 본 논문에서는 챗 GPT 를 활용 시 발생하는 문제와 한계에 대하여 살펴본다. 챗 GPT 의 문제점에는 챗 GPT 로 악성코드를 작성하는 사이버 범죄, 개인정보 침해 문제, 챗 GPT 로 과제 작성, 타인에게 챗 GPT 와 대화한 내용이 보이는 보안의 취약점이 발견되는 등이 있다. 챗 GPT 의 한계로는 실시간 학습 불가, 아는 것과 모르는 것의 구분 불가, 저작권 침해와 편향성과 같은 것이 있다. 본 논문이 챗 GPT 의 해결 가능한 문제를 신속하게 해결하고 남아있는 한계에 대한 잠재적인 해결책을 파악하는 데 도움이 되기를 기대한다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.2
• /
• pp.165-171
• /
• 2013

Due to the difficulty in considering dynamic load in the view point of a computer resource and computing time, it is common that external load is assumed as ideal static loads. However, structural analysis under static load cannot guarantee the safety of design of the structures under dynamic loadings. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. However, previously reported works to distribute equivalent static load were based on ad-hoc methods. Improper selection of equivalent static loading positions may results in unreliable prediction of structural design. The present study proposes the selection method of the proper locations of equivalent static loads to dynamically applied loads when we consider transient dynamic structural problems. Moreover, it is appropriate to take into account the stress constraint as well as displacement constraint condition for the safety design. But the previously reported studies of equivalent static load design methods considered only displacement constraint conditions but not stress constraint conditions. In the present study we consider not only displacement constraint but also stress constraint conditions. Through a few numerical examples, the efficiency and reliability of proposed scheme is verified by comparison of the equivalent stress between equivalent static loading and dynamic loading.

• Journal of Broadcast Engineering
• /
• v.15 no.2
• /
• pp.163-172
• /
• 2010

The free viewpoint video delivers an active contents where users can see the images rendered from the viewpoints chosen by them. Its applications are found in broad areas, especially museum tour, entertainment and so forth. As a new free-viewpoint application, this paper presents a stereoscopic free-viewpoint TIP (Tour Into Picture) where users can navigate the inside of a single image controlling a virtual camera and utilizing depth data. Unlike conventional TIP methods providing 2D image or video, our proposed method can provide users with 3D stereoscopic and free-viewpoint contents. Navigating a picture with stereoscopic viewing can deliver more realistic and immersive perception. The method uses semi-automatic processing to make foreground mask, background image, and depth map. The second step is to navigate the single picture and to obtain rendered images by perspective projection. For the free-viewpoint viewing, a virtual camera whose operations include translation, rotation, look-around, and zooming is operated. In experiments, the proposed method was tested eth 'Danopungjun' that is one of famous paintings made in Chosun Dynasty. The free-viewpoint software is developed based on MFC Visual C++ and OpenGL libraries.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.24 no.3
• /
• pp.253-258
• /
• 2013

In this paper, a free-space material measurement technique is discussed in W-band(75~110 GHz). For the accurate measurement of S-parameters of an MUT(Material Under Test) in free space, a W-band quasi-optical free-space material measurement system, less affected by the measurement environments, is discussed, and GRL(Gated Reflect Line) method for calibrating the measurement system is described. Proposed technique is verified for 'Air' and measurement results for arystal plates of thickness 1.1 mm, 2 mm, 2.75 mm and 5 mm are also shown.

• Journal of Korea Water Resources Association
• /
• v.45 no.4
• /
• pp.349-360
• /
• 2012

A horizontally curvilinear non-hydrostatic free surface model that was applicable to three-dimensional viscous flows was developed. The proposed model employed a top-layer equation to close kinematic free-surface boundary condition, and an isotropic k-${\varepsilon}$ model to close turbulence viscosity in the Reynolds averaged Navier-Stokes equation. The model solved the governing equations with a fractional step method, which solved intermediate velocities in the advection-diffusion step, and corrects these provisional velocities by accounting for source terms including pressure gradient and gravity acceleration. Numerical applications were implemented to the wind-driven currents in a two-dimensional closed basin, the flow in a steep-sided trench, and the flow in a strongly-curved channel accounting for secondary current by the centrifugal force. Through the numerical simulations, the model showed its capability that were in good agreement with experimental data with respect to free surface elevation, velocity, and turbulence characteristics.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.3 no.1
• /
• pp.1-7
• /
• 2012

This study investigates free vibration characteristics of laminated composite structures with different embedded delamination sizes and locations using the solid element. The three-dimensional finite element (FE) delamination model described in this paper, in comparison with the conventional approaches, is more attractive not only because it shows better accuracy but also it shows the entire mode shape. The FE model using ABAQUS is used for studying free vibrations of laminates containing an various embedded delamination. The numerical results obtained are in good agreement with those reported by other investigators. In particular, new results reported in this paper are focused on the significant effects of the local vibration mode for various parameters, such as size of delamination, aspect ratio, and location of delamination.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.12
• /
• pp.1917-1923
• /
• 2010

This study focuses on model identification and a 2-DOF PID control algorithm for cooling processes; a pneumatic butterfly-type control valve is used for this purpose. The mathematical model is a transfer function composed of a time delay and a second-order delay system. The control valve is identified as a first-order delay system with a time delay and included in the controlled plant. From the experimental data sets for a demo plant, the model parameters are identified, and the 2-DOF PID control gains are analytically derived by Kitamori's method. We show via a computer simulation and an experimental test that the performance of the proposed 2-DOF PID control system is better than that of a conventional 1-DOF PID control system.

• Journal of the Society of Naval Architects of Korea
• /
• v.33 no.2
• /
• pp.13-29
• /
• 1996

This paper presents calculated results of the free-surface flow around a Series 60($C_B=0.6$) model. Three-dimensional Navier-Sotkes equations are solved and Baldwin-Lomax algebraic turbulence model is adopted to simulate the high Reynolds-number flow. To reduce computational efforts, velocity components near the wall are extrapolated with a the solved by using the Implicit Approximate Factorization method[2]. The successive-over-relaxation method is used for solving pressure-Poisson equation when obtaining the pressure field projecting the divergence-free velocity field. To simulate the free-surface flows more precisely, the numerical scheme solving the equation for the kinematic boundary condition is very important. In this paper, there numerical schemes are employed and the results are compared with the available experimental data.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.17 no.3
• /
• pp.279-293
• /
• 2004

The analysis of linear static and free vibration problems of isotropic and laminated composite plates and shells is performed by the improved 9-node shell element with the new strain displacement relationship. In that relationship, the effect of new additional terms between the bending strain and displacement has been investigated in the warping problem. Natural co ordinate based strains, stresses and constitutive equations are used. The assumed natural strain method is used to alleviate both membrane and shear locking behavior from the element. The Lanczos method is employed in the calculation of the eigenvalues of laminated composite structures and the Gauss integration rule is adopted to evaluate the mass matrix. The numerical examples are compared with the analytical solutions to validate the current formulation and the results presented could be useful for the understanding of the behaviour of laminates under free vibration conditions.

• Korean journal of communication and information
• /
• v.57
• /
• pp.160-180
• /
• 2012

This research points out how the major newspapers and the Local newspaper try to report the issue of development in Incheon Free Economic Zone differently and observe how the press has played a role in a process. It is seen that the type of story-leading has been followed by properly traditional one as usual and reflected the recent trends well in both. The perspectives of ChosunIlbo to look at the regional issue is taken in the situation of a middle clear attitude but KyeonginIlbo is faithful to make the position of the monitor. In other words, a Metropolitan newspaper often deals with the regional issues in a more passive posture, while a Local daily newspaper tries to report the same issue in a more positive and active form. This kind of attitude upon news composition reflects the quality of the news, which is a standard of actual newspaper articles. The ChosunIlbo focuses on the political issues more while, KyeonginIlbo emphasizes on the cultural similarities. And they trace the economic importance, human interest but less to the structural figures.