• 소성∙가공
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• 제9권4호
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• pp.372-378
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• 2000

A process model including the effects of both the texture development and ductile damage evolution In plane strain rolling is presented. In this process model, anisotropy from deformation texture and deterioration of mechanical properties due to growth of micro voids are directly coupled Into the virtual work expressions for the momentum and mass balances. Special treatments in obtaining the initial values of field variables in the nonlinear simultaneous equations for the anisotropic, dilatant viscoplastic deformation are also given. Mutual effects of the texture development and damage evolution during plate rolling are carefully examined in terms of the distribution of strain components, accumulated damage, R-value as well as yield surfaces.

• 한국산업융합학회 논문집
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• 제18권4호
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• pp.191-196
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• 2015

In this paper, we present a path-smoothing algorithm for a robot arm manipulator that finds the path using a joint space-based rapidly-exploring random tree. Unlike other smoothing algorithms which require complex mathematical computation, the proposed path-smoothing algorithm is done using a Gaussian process. To find the optimal hyperparameters of the Gaussian process, we use differential evolution hybridized with opposition-based learning. The simulation result indicates that the Gaussian process whose hyperparameters were optimized by hybrid differential evolution successfully smoothed the path generated by the joint space-based rapidly-exploring random tree.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2002년도 봄 학술발표회 논문집
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• pp.18-19
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• 2002

• 한국경제지리학회지
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• 제15권4호
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• pp.628-641
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• 2012

이 연구에서는 네트워크와 공간의 형성과정을 사회와 기술의 변화를 나타내는 공진화(co-evolution)현상의 하이프 곡선을 이용하여 고찰해 보았다. 이를 위해 공진화 현상의 초기 네트워크의 출현과 공간적 사회화 시작, 외부와의 상호작용을 통한 기대감 최고조, 기대의 반작용, 학습단계, 안정적인 사회적 수용과 내면화 단계에 적용하여 분석하였다. 이 연구는 공간과 네트워크의 공진화(co-evolution) 작용메커니즘을 기관유형별로 시간적 변화를 통해 고찰하였다는 특징이 있다. 네트워크는 공간 정책에 의해 상호 피드백을 형성하며 진화와 분화를 반복하며 형성된다. 또한 네트워크와 공간의 상호작용단계에서 정책에 대한 기대와 실망 그리고 조정 등의 사회적 수용과정에서 나타나는 시간적 지연(delay)의 가시성을 보인다. 초기 성장거점의 발전 단계를 지나 균형발전 그리고 광역발전으로 이루어지는 공간정책이 네트워크 성장에 중요한 영향을 미치고 있다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.130-133
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• 2008

The formability of DP steels can be affected by not only initial texture but also deformation texture evolved during plastic deformation. To investigate the evolution of deformation texture during deep drawing, deep drawing process for DP steels was carried out experimentally. A rate sensitive polycrystal model was used to predict texture evolution during deep drawing process. In order to evaluate the strain path during deep drawing, a steady state was assumed in the flange part of deep drawn cup. A rate sensitive polycrystal model successfully predicted the texture development in DP steels during deep drawing process. It was found that the final stable orientations were strongly dependent on the initial location in the blank.

• 상하수도학회지
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• 제31권5호
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• pp.373-381
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• 2017

$RuO_2$ is a common active component of Dimensionally Stable Anodes (DSAs) for chlorine evolution that can be used in wastewater treatment systems. The recent improvement of chlorine evolution using nanostructures of $RuO_2$ electrodes to increase the treatment efficiency and reduce the energy consumption of this process has received much attention. In this study, $RuO_2$ nanorod and nanosheet electrodes were simply fabricated using the sol-gel method with organic surfactants as the templates. The obtained $RuO_2$ nanorod and nanosheet electrodes exhibit enhanced electrocatalytic activities for chlorine evolution possibly due to the active surface areas, especially the outer active surface areas, which are attributed to the increase in mass transfers compared with a conventional nanograin electrode. The electrocatalytic activities for chlorine evolution were increased up to 20 % in the case of the nanorod electrode and 35% in the case of the nanosheet electrode compared with the nanograin electrode. The $RuO_2$ nanorod 80 nm in length and 20-30 nm in width and the $RuO_2$ nanosheet 40-60 nm in length and 40 nm in width are formed on the surface of Ti substrates. These results support that the templated $RuO_2$ nanorod and nanosheet electrodes are promising anode materials for chlorine evolution in future applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4191-4211
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• 2019

Software product lines (SPLs) are complex software systems by nature due to their common reference architecture and interdependencies. Therefore, any form of evolution can lead to a more complex situation than a single system. On the other hand, software product lines are developed keeping long-term perspectives in mind, which are expected to have a considerable lifespan and a long-term investment. SPL development organizations need to consider software evolution in a systematic way due to their complexity and size. Addressing new user requirements over time is one of the most crucial factors in the successful implementation SPL. Thus, the addition of new requirements or the rapid context change is common in SPL products. To cope with rapid change several researchers have discussed the evolution of software product lines. However, for the evolution of an SPL, the literature did not present a systematic process that would define activities in such a way that would lead to the rapid evolution of software. Our study aims to provide a requirements-driven process that speeds up the requirements engineering process using social network sites in order to achieve rapid software evolution. We used classification, topic modeling, and sentiment extraction to elicit user requirements. Lastly, we conducted a case study on the smartwatch domain to validate our proposed approach. Our results show that users' opinions can contain useful information which can be used by software SPL organizations to evolve their products. Furthermore, our investigation results demonstrate that machine learning algorithms have the capacity to identify relevant information automatically.

• 영어영문학
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• 제58권4호
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• pp.655-678
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• 2012

Doris Lessing, who considers science and technology as instruments of capitalism, deals with the theme of 'biological evolution' in The Sirian Experiments, the third book in the Canopus in Argos: Archives series. One of her themes that repeats throughout is that of 'spiritual evolution,' and in The Four-Gated City she even used 'biological evolution' as its metaphor. This paper analyzes The Sirian Experiments using scientific knowledge such as the concept of 'biological evolution' from Charles Darwin's evolution theory and Edward O. Wilson's sociobiology. Lessing concludes that while 'biological evolution' not accompanied with 'spiritual evolution' puts humans in existential problems and mental breakdown, the one in equilibrium with the other can bring social and political revolution. Lessing's concept of 'spiritual evolution' is basically a product of her holistic view and her own philosophical view that human evolution is a necessary process following the Universal Order, which shows that she is influenced by Sufism. The basic tenet in Sufi philosophy is to achieve equilibrium between the rational and non-rational modes of consciousness. Lessing incorporates her rational and irrational ideas into The Sirian Experiments to make a field for confluence where the biological, the sociological, and the spiritual thinking converge.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.102-105
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• 2008

To investigate the evolution of deformation texture during cold rolling deformation, cold rolling process on a commercial Al-5% Mg sheet was carried out at different rolling reduction ratio. The evolution of annealing texture in cold-rolled Al-5% Mg sheet was also investigated. The evolution of recrystallization texture during annealing process strongly depends on the rolling reduction ratio before heat treatment. Visco-plastic self-consistent (VPSC) polycrystal model was used to predict r-value anisotropy of the cold-rolled and annealed Al-5% Mg sheets. The change of volume fraction for the major texture components was also analyzed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.219-222
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• 1995

The objective of this study is to demonstrate the ability of a computer simulation of microstructural evolution in hot forging of C-Mn steels. The finite element method is applied to the prediction of the microstructural evolution, and it should be coupled with heat transfer analysis to consider the change of thermomechanical properties during the deformation. In this study, Yada's recrystallization model and rigid-thermoviscoplastic finite element method were employed in order to analyze microstructural evolution during hot forging process. To show the validity and effectveness of the proposed method, the experiment of hot compression process was accomplished and the results of experiment were compared with those of simulation. Consequently, this approach shows a good agreement with experimental results.