• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.227-232
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• 2010

In this paper we consider the multi-robot system that collects target objects spread in an unexplored environment. The robots cooperate each other to improve the capability and the efficiency. The robots attract or intimidate each other as behaviors of bacterial swarms or particles with electrical moments. The interactions would increase the working efficiency in some environments but it would decrease the efficiency in some other environments. Therefore, the system needs to adapt to the working environment by adjusting the strengths of the interactions. The strengths of the interactions are expressed as sets of gene codes that mean the weights of each kind of attracting or intimidating vectors. The proposed system adjusts the gene codes using evolutional strategy. The proposed approach has been validated by computer simulation. The results of this paper show that our inter-swarm interacting strategy and optimizing algorithm improves the working efficiency, adaptively to the characteristics of environments.

• Advances in Computational Design
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• 제1권3호
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• pp.275-296
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• 2016

This article presents an adaptive directional differential evolution (ADDE) algorithm and its application in solving discrete sizing truss optimization problems. The algorithm is featured by a new self-adaptation approach and a simple directional strategy. In the adaptation approach, the mutation operator is adjusted in accordance with the change of population diversity, which can well balance between global exploration and local exploitation as well as locate the promising solutions. The directional strategy is based on the order relation between two difference solutions chosen for mutation and can bias the search direction for increasing the possibility of finding improved solutions. In addition, a new scaling factor is introduced as a vector of uniform random variables to maintain the diversity without crossover operation. Numerical results show that the optimal solutions of ADDE are as good as or better than those from some modern metaheuristics in the literature, while ADDE often uses fewer structural analyses.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 춘계학술대회 학술발표 논문집
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• pp.127-130
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• 1998

In this paper, we propose a method of cooperative control(T-cell modeling) and selection of group behavior strategy(B-cell modeling) based on immune system in distributed autonomous robotic system(DARS). Immune system is living body's self-protection and self-maintenance system. Thus these features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For the purpose of applying immune system to DARS, a robot is regarded as a B cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-call respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control scheme is based of clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

• 환경영향평가
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• 제28권1호
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• pp.1-22
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• 2019

본 연구에서는 국가 생태분야 기후변화 리스크 평가와 연계한 적응 정책 및 연구의 방향성에 대한 시사점을 마련하고자 하였다. 본 논문에서 검토한 적응 정책과 연구에 대한 해외 모범사례의 공통점은 국가 적응정책 수립 시 과학적 근거기반 구축 및 불확실성 저감을 목표로 국가단위에서 기후변화가 생물다양성과 생태계에 미치는 영향 연구를 강조한다는 점이다. 이에 비추어 추후 국가 정책 마련 시 기후변화 협약과 생물다양성 협약 등 효율적 통합적 준수를 위한 적응체계를 유도하고, 적응의 경제적 가치평가를 통한 정책 반영, 과학적 연구 프로그램 강화 및 기술 개발의 측면을 보강하여 보다 성공적인 국가적응 정책 구조를 정착해 갈 수 있어야 할 것이다. 특히 생태계 분야 적응방안이 보다 실효성 있게 실행되기 위해서는 우리나라 서식지 및 종의 기후변화 리스크 요소(위해, 노출, 취약성)에 대한 과학적 진단과 분석을 바탕으로 리스크를 평가하고 이에 대한 적응방안을 통합하여 고민하는 노력이 필요할 것이다.

• Structural Engineering and Mechanics
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• 제44권3호
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• pp.379-403
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• 2012

In recent years, the need for optimal design of structures under time-history loading aroused great attention in researchers. The main problem in this field is the extremely high computational demand of time-history analyses, which may convert the solution algorithm to an illogical one. In this paper, a new framework is developed to solve the size optimization problem of steel truss structures subjected to ground motions. In order to solve this problem, the covariance matrix adaptation evolution strategy algorithm is employed for the optimization procedure, while a generalized regression neural network is utilized as a meta-model for fitness approximation. Moreover, the computational cost of time-history analysis is decreased through a wavelet analysis. Capability and efficiency of the proposed framework is investigated via two design examples, comprising of a tower truss and a footbridge truss.

• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.25-31
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• 2008

It is well known that temporal information, i.e speech onset, about input speech can be represented to the response nerve signal of auditory nerve better depending on the adaptation effect occurred in the auditory nerve synapse. In addition, the performance of a speech processor of cochlear implant can be improved by the adaptation effect. In this paper, we observed the emphasis characteristic of speech onset in the recently proposed adaptation algorithm, analyzed the characteristic of performance change according to the variation of parameters and compared with transient emphasis spectral maxima (TESM) is the previous typical strategy. When observing false peaks which are generated everywhere except speech onset, in the case of the proposed model, the false peak were generated much less than in the case of the TESM and it is more distinguishable under noise.

• 한국기후변화학회지
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• 제5권3호
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• pp.257-266
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• 2014

This study aims to understand abnormal climate caused by impacts of climate change and to suggest the direction of urban planning focusing on adaptation to climate change. The study consists of theory consideration and case study(Chicago, Philadelphia, Seattle). As a result, the main impacts of climate change faced by urban areas are heat wave, precipitation, and drought. To prevent these impacts, it is important to prepare methods of urban planning as followings: planning for land use, park and green considering the climate patterns, establishing and managing water resources systems similar to the nature, securing renewable energy resources, and transportation facilities and exterior space with proof against climate. It is especially necessary to introduce infrastructures related to storm water, green roof, shading tree planting, green space, and permeable pavement. Finally, in order to realize urban planning for adaptation to climate change, it is needed to make the detailed and specific goal and strategy for the climate change adaptation plan and to extend the scope from the goals to an action plan, a detailed plan, and a design guideline.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1599-1604
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• 2022

Storage stability of freeze-dried lactic acid bacteria is a critical factor for their cost-effectiveness. Long-term storage of lactic acid bacteria enables microbial industry to reduce distribution costs. Herein, we investigated the effect of cold adaptation under supercooling conditions at -5℃ on the viability of Leuconostoc mesenteroides WiKim32 during the freeze-drying process and subsequent storage. Cold adaptation increased the thickness of exopolysaccharides (EPS) and improved the viability of freeze-dried Leu. mesenteroides WiKim32. Compared to non-adapted cells, cold-adapted cells showed a 35.4% increase in EPS thickness under supercooling conditions. The viability of EPS-hydrolyzed cells was lower than that of untreated cells, implying that EPS plays a role in protection during the freeze-drying process. Cold adaptation increased the storage stability of freeze-dried Leu. mesenteroides WiKim32. Fifty-six days after storage, the highest viability (71.3%) was achieved with cold adaptation at -5℃. When EPS-containing broth was added prior to the freeze-drying process, the viability further increased to 82.7%. These results imply that cold adaptation by supercooling pretreatment would be a good strategy for the long-term storage of Leu. mesenteroides WiKim32.

• 국제지역연구
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• 제14권2호
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• pp.229-248
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• 2010

본 연구는 한국 기업의 글로벌마케팅 프로그램의 표준화-현지화 정도를 결정하는 요인에 관한 실증적 연구이다. 특히 본 연구는 2가지 관점에서 기존 연구와 차별화하고자 하였다. 첫째는 모국-현지국의 환경 차이에 초점을 두는 기존 실증연구와는 달리 글로벌 관점에서 분석하고자 하였다. 두 번째는 본 연구는 상황접근론 관점과 자원기반 관점에서 결정요인을 설정하고 이들 요인의 효과를 검증하고자 하였다. 구체적인 결정요인으로 상황적응론적 관점에서 외부환경 요인인 글로벌 시장의 역동성과 복잡성을, 그리고 자원기반 관점에서 글로벌 마케팅자산을 설정하고 검증하였다. 이를 위해 국제마케팅을 수행하는 국내 기업 128개 업체를 대상으로 설문조사를 실시하였다. 연구 결과, 기업의 글로벌 마케팅자산은 글로벌마케팅 프로그램 표준화 정도와의 정(正)의 관계를 나타는 것으로 나타난 반면에, 글로벌 시장환경 요인은 통계적으로 유의한 관계가 없는 것으로 나타났다. 이는 기업의 글로벌마케팅 프로그램은 상황적응론적 관점보다는 자원기반 관점에서 결정되는 경향이 있음을 사사하는 결과이다.

• 해양환경안전학회지
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• 제10권2호
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• pp.81-88
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• 2004

본 연구는 21세기 기후변화에 대한 적응전략을 해수면 상승 관점에서 검토하였다. 해수면 상승에 취약한 것으로 알려진 연안역에 대한 적응책을 고려하는 경우 적응이 필요한 장소, 적응방법, 적응시기에 대한 검토가 필요하다. 연안역에 대한 적응 능력 평가는 영향 및 적응 잠재력에 대한 이해를 필요로 한다. 해수면 상승에 대한 적응방법에는 관리적 이주, 순응, 방어가 있으며, 이들의 적용에는 취약지대 토지이용 상황, 취약성 정도, 경제성 분석 등의 검토를 통한 대응 방안의 조합이 요구된다. 적응시기에 대하여는 예측적 적응과 반응적 적응으로 구분할 수가 있으며, 이들을 함께 고려하는 것이 효과적이다. 기후변화 대응은 과학적 불확실성 하에서 이루어지는 과정으로 대응정책 결정은 정보와 인식 구축, 계획 및 정책 구상, 실행, 모니터링 및 평가의 단계로 이루어져야 한다.