• 한국산업정보학회논문지
• /
• 제22권1호
• /
• pp.89-104
• /
• 2017

본 연구는 경쟁시장에서 기업의 기술혁신이 정체되는 이유를 '소비자의 기술이해도'와 '진화게임이론'을 사용하여 설명하고자 한다. 본 연구에서 소비자의 행동은 I영역과 II영역으로 나누어진다. 본 연구의 내용은 다음과 같이 정리할 수 있다. 먼저, I영역에서 무수히 많은 기업들은 기술경쟁을 통해 동일 범주 디지털제품의 기술적 속성을 급속히 발전시키려고 노력하며, 소비자집단은 자신들의 소비패턴을 저기술 제품에서 고기술 제품으로 빠르게 이행하려고 한다. 반면, II영역은 소비자의 기술 이해력이 점점 약해지는 구간으로 기술이 발전함에 따라 소비자집단의 제품사용에 대한 효용이 서서히 감소한다. 이에 기업들은 현재의 기술수준에 최대한 머무르고자 하고, 소비자집단 역시 이 시점의 제품기술을 최적이라고 생각하게 되면서 결국 기업들은 기술혁신을 늦추게 된다.

• 기술혁신학회지
• /
• 제20권1호
• /
• pp.103-126
• /
• 2017

빠르게 변화하는 경쟁 환경에서 ICT 기업은 다른 산업 기술과의 결합을 통해 경쟁 우위를 얻으려 하고 다른 산업의 기업 또한 ICT와의 결합을 통해 혁신을 얻고자 한다. ICT 공급자에게 이전에는 완전히 다른 산업이 일단 ICT가 적용되면 그들의 시장으로 볼 수 있는 융합 현상이 나타나는 것이다. 본 연구는 ICT 기업이 기술 융합을 위해서 어떠한 노력을 해야 하는지에 대한 연구문제를 가지고 진화론적 관점에서 ICT 공급자의 행동과 기술 융합과 관계에 관심을 갖는다. 실증적으로 ICT 융합이 가장 활발하게 진행되는 자동차 분야를 대상으로 나스닥 등록 기업의 특허활동에 따른 10년간의 기술 변화를 관찰하였다. ICT 공급자에 의한 기술적 시도의 혁신성은 기술 융합의 가능성을 높이지만 그 다양성은 그렇지 못하다는 결론을 얻음으로써 급변하는 환경에 대응하기 위해서 ICT 기업은 다양한 대안을 마련하는 것 보다는 집중이 필요하다는 시사점을 전달한다.

• Structural Engineering and Mechanics
• /
• 제84권2호
• /
• pp.143-154
• /
• 2022

Corrosion of steel reinforcement is considered as the main cause of concrete structures deterioration, especially those under humid environmental conditions. Hence, fiber reinforced polymer (FRP) bars are being increasingly used as a replacement for conventional steel owing to their non-corrodible characteristics. However, predicting the shear strength of beams reinforced with FRP bars still challenging due to the lack of robust shear theory. Thus, this paper aims to develop an explicit data driven based model to predict the shear strength of FRP reinforced beams using multi-objective evolutionary polynomial regression analysis (MOGA-EPR) as data driven models learn the behavior from the input data without the need to employee a theory that aid the derivation, and thus they have an enhanced accuracy. This study also evaluates the accuracy of predictive models of shear strength of FRP reinforced concrete beams employed by different design codes by calculating and comparing the values of the mean absolute error (MAE), root mean square error (RMSE), mean (𝜇), standard deviation of the mean (𝜎), coefficient of determination (R²), and percentage of prediction within error range of ±20% (a20-index). Experimental database has been developed and employed in the model learning, validation, and accuracy examination. The statistical analysis illustrated the robustness of the developed model with MAE, RMSE, 𝜇, 𝜎, R², and a20-index of 14.6, 20.8, 1.05, 0.27, 0.85, and 0.61, respectively for training data and 10.4, 14.1, 0.98, 0.25, 0.94, and 0.60, respectively for validation data. Furthermore, the developed model achieved much better predictions than the standard predictive models as it scored lower MAE, RMSE, and 𝜎, and higher R² and a20-index. The new model can be used in future with confidence in optimized designs as its accuracy is higher than standard predictive models.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
• /
• pp.679-682
• /
• 2003

In this paper, we propose a Genetic Algorithm (GA) using symbiotic evolutionary viruses. Our GA is based on both the building block hypothesis and the virus theory of evolution. The proposed GA aims to control a destruction of building blocks by discovering, keeping, and propagating of building blocks based on virus operation. Concretely, we prepare the group of individuals and the group of viruses. In our GA, the group of individuals searches solutions and the group of viruses searches building blocks. These searches done based on the symbiotic relation of both groups. Also, our GA has two types of virus evaluation techniques. One is that each virus is evaluated by the difference of the fitness of an individual between before and after infection of virus. Another is that all viruses aye evaluated by the difference of the fitness of an individual between before and after infection of all viruses. Furthermore, we applied the proposed GA to the minimum value search problem of a test function which has some local solutions far from the optimal solution. And, we discuss a difference of behaviors of the proposed GA based on each virus evaluation techniques.

• Wind and Structures
• /
• 제17권2호
• /
• pp.227-244
• /
• 2013

Non-stationary extreme winds such as thunderstorm downbursts are responsible for many structural damages. This research presents a time domain approach for estimating along-wind load effects on tall buildings using multiple wind speed time history samples, which are simulated from evolutionary power spectra density (EPSD) functions of non-stationary wind fluctuations using the method developed by the authors' earlier research. The influence of transient wind loads on various responses including time-varying mean, root-mean-square value and peak factor is also studied. Furthermore, a simplified model is proposed to describe the non-stationary wind fluctuation as a uniformly modulated process with a modulation function following the time-varying mean. Finally, the probabilistic extreme response and peak factor are quantified based on the up-crossing theory of non-stationary process. As compared to the time domain response analysis using limited samples of wind record, usually one sample, the analysis using multiple samples presented in this study will provide more statistical information of responses. The time domain simulation also facilitates consideration of nonlinearities of structural and wind load characteristics over previous frequency domain analysis.

• 인지과학
• /
• 제15권4호
• /
• pp.61-66
• /
• 2004

서양철학의 근간을 이루는 데카르트의 이성주의적 인간이해의 반성으로부터 등장한 구성주의는 지능을 포함한 인간이해의 새로운 대안이 될 수 있을 것으로 생각한다. 구성주의는 진화생물학, 진화심리학, 뇌과학, 시스템이론, 복잡계 이론의 성과뿐만 아니라 나아가 인문사회학의 경향과도 설명을 공유할 수 있는 많은 부분이 있다. 또한 인공지능 분야에서도 구성주의적 방법이라고 할 수 있는 연구가 진행되고 있다. 이 글에서는 구성주의적 관점에서 인공지능에서 다루는 지능에 대한 이해의 지평을 넓히고 이를 기반으로 한 방법론에 대한 검토와 그러한 경향에 있는 일부 인공지능 기술을 살펴보고자 한다. 이러한 논의를 통하여 여러 가지 관점의 마음에 대한 이론과 기술을 상호보완적으로 이해하고 다소 등한히 되고 있는 인공지능의 보편지능(general intelligence)의 토대로 삼고자 한다.

• Structural Engineering and Mechanics
• /
• 제24권2호
• /
• pp.213-225
• /
• 2006

The propagation of non-uniformly modulated, evolutionary random waves in viscoelastic, transversely isotropic, stratified materials is investigated. The theory is developed in the context of a multi-layered soil medium overlying bedrock, where the material properties of the bedrock are considered to be much stiffer than those of the soil and the power spectral density of the random excitation is assumed to be known at the bedrock. The governing differential equations are first derived in the frequency/wave-number domain so that the displacement response of the ground may be computed. The eigen-solution expansion method is then used to solve for the responses of the layers. This utilizes the precise integration method, in combination with the extended Wittrick-Williams algorithm, to obtain all the eigen-solutions of the ordinary differential equation. The recently developed pseudo-excitation method for structural random vibration is then used to determine the solution of the layered soil responses.

• 천문학회보
• /
• 제43권2호
• /
• pp.32.1-32.1
• /
• 2018

The galactic warp is almost ubiquitous among disk galaxies and suspected to be an imprint of recent interactions with other galaxies. The detailed evolutionary course, however, is still uncertain due to the lack of observational evidence. To address this issue, we construct a new extensive catalog of 412 conspicuously warped disks at z = 0.01 ~ 0.05, based on SDSS DR7. We classify the warp morphology through a visual inspection from the Zooniverse Project and our new automated scheme for the warp measurement. We find an interesting color difference between S-and U-shaped warps. The U-type warp galaxies exhibits considerable color offset towards blue compared to both the S-type warps and the control sample of un-warped galaxies. The effect is even more pronounced for galaxies (a) with the greater warp amplitude and (b) with lower luminosity. This is the first piece of observational evidence that the S- and U-shaped warps are on different evolutionary phases in terms of not only dynamics but stellar populations as well. We discuss the implications in the context of the warp evolution theory.

• Advances in Computational Design
• /
• 제7권1호
• /
• pp.1-17
• /
• 2022

In this study, a new strategy is presented to transmit the fundamental elastic beam problem into the modern optimization platform and solve it by using artificial intelligence (AI) tools. As a practical example, deflection of Euler-Bernoulli beam is mathematically formulated by 2nd-order ordinary differential equations (ODEs) in accordance to the classical beam theory. This fundamental engineer problem is then transmitted from classic formulation to its artificial-intelligence presentation where the behavior of the beam is simulated by using neural networks (NNs). The supervised training strategy is employed in the developed NNs implemented in the heuristic optimization algorithms as the fitness function. Different evolutionary optimization tools such as genetic algorithm (GA) and particle swarm optimization (PSO) are used to solve this non-linear optimization problem. The step-by-step procedure of the proposed method is presented in the form of a practical flowchart. The results indicate that the proposed method of using AI toolsin solving beam ODEs can efficiently lead to accurate solutions with low computational costs, and should prove useful to solve more complex practical applications.

• Structural Engineering and Mechanics
• /
• 제72권2호
• /
• pp.275-291
• /
• 2019

In a super-large underground with "large span and high side wall", it is buried in mountains with uneven lithology, complicated geostress field and developed geological structure. These surrounding rocks are more susceptible to stability issues during the construction period. This paper takes the left bank of Baihetan hydropower station (span is 34m) as a case study example, wherein the deformation mechanism of surrounding rock appears prominent. Through analysis of geological, geophysical, construction and monitoring data, the deformation characteristics and factors are concluded. The failure mechanism, spatial distribution characteristics, and evolution mechanism are also discussed, where rock mechanics theory, $FLAC^{3D}$ numerical simulation, rock creep theory, and the theory of center point are combined. In general, huge underground cavern stability issues has arisen with respect to huge-scale and adverse geological conditions since settling these issues will have milestone significance based on the evolutionary pattern of the surrounding rock and the correlation analyses, the rational structure of the factors, and the method of nonlinear regression modeling with regard to the construction and development of hydropower engineering projects among the worldwide.