• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.422-424
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• 2022

우리는 부모 개체 선택을 위한 새로운 데이터 기반 돌연변이 전략, 즉 parapatric 및 cross-generation(TPCDE)이 있는 텐서 기반 DE를 제안합니다.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1412-1419
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• 2023

Retroviral integration into ancient vertebrate genomes left traces that can shed light on the early history of viruses. In this study, we explored the early evolution of retroviruses by isolating nine Spuma endogenous retroviruses (ERVs) and one Epsilon ERV from the genomes of Agnatha and Chondrichthyes. Phylogenetic analysis of protein sequences revealed a striking pattern of co-evolution between jawless fish ERV and their host, while shark ERV underwent ancient cross-class viral transmission with jawless fish, ray-finned fish, and amphibians. Nucleotide sequence analysis showed that jawless fish ERV emerged in the Palaeozoic period, relatively later than ray-finned fish ERV. Moreover, codon analysis suggested that the jawless fish ERV employed an infection strategy that mimics the host codon. The genealogical diversity of ERVs in the jawless fish genome highlights the importance of studying different viral species. Overall, our findings provide valuable insights into the evolution of retroviruses and their interactions with their hosts.

• 대한조선학회논문집
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• 제48권2호
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• pp.178-182
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• 2011

Generally in order to reduce the steel weight of stiffened plate, stiffener spaces tend to be narrow and the plate gets thin. However, it will involve more fabrication cost because it can lead to the increase of welding length and the number of structural members. In the yard, the design which is able to reduce the total fabrication cost is needed, although it requires more steel weight. The purpose of this study is to find optimum stiffener spaces to minimize the fabrication cost for the cargo tank of LPG Carriers. Global optimization methods such as ES(Evolution Strategy) and GA(Genetic Algorithm) are introduced to find a global optimum solution and the sum of steel material cost and labor cost is selected as main objective function. Convergence degree of both methods in according to the size of searching population is examined and an efficient size is investigated. In order to verify the necessity of the optimum design based on the cost, minimum weight design and minimum cost design are carried out.

• 디지털융복합연구
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• 제14권8호
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• pp.293-303
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• 2016

근래에 진화 연산을 활용한 교섭 게임의 분석은 게임 이론 분야에서 중요한 문제로 다루어지고 있다. 본 논문은 교섭 게임에서 진화 연산을 사용하여 이기종 인공 에이전트 간의 상호 작용 및 공진화 과정을 조사하였다. 교섭게임에 참여하는 진화전략 에이전트들로서 유전자 알고리즘(GA), 입자군집최적화(PSO) 및 차분진화알고리즘(DE) 3종류를 사용하였다. GA-agent, PSO-agent 및 DE-agent의 3가지 인공 에이전트들 간의 공진화 실험을 통해 교섭게임에서 가장 성능이 우수한 진화 계산 에이전트가 무엇인지 관찰 실험하였다. 시뮬레이션 실험결과, PSO-agent가 가장 성능이 우수하고 그 다음이 GA-agent이며 DE-agent가 가장 성능이 좋지 않다는 것을 확인하였다. PSO-agent가 교섭 게임에서 성능이 가장 우수한 이유를 이해하기 위해서 게임 완료 후 인공 에이전트 전략들을 관찰하였다. PSO-agent는 거래 실패로 인해 보수를 얻지 못하는 것을 감수하고서라도 가급적 많은 보수를 얻기 위한 방향으로 진화하였다는 것을 확인하였으며, 반면에 GA-agent와 DE-agent는 소량의 보수를 얻더라도 거래를 성공시키는 방향으로 진화하였다는 것을 확인하였다.

• Corrosion Science and Technology
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• 제22권5호
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• pp.341-350
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• 2023

In the present study, effects of a thin Zn-flash coating on hydrogen evolution, infusion, and embrittlement of advanced high strength steel during electro-galvanizing were examined. The electrochemical permeation technique in conjunction with impedance spectroscopy was employed under applied cathodic polarization. Moreover, a slow-strain rate test was conducted to evaluate loss of elongation (i.e., indicative of hydrogen embrittlement (HE)) and examine fracture surfaces. Results showed that the presence of a thin Zn-flash coating, even when it was not distributed uniformly, reduced hydrogen evolution rate and substantially impeded infusion of hydrogen into the steel substrate. This was primarily due to a hydrogen overvoltage on Zn coating and trapping of hydrogen at the interface of Zn coating/flash coating/steel substrate. Consequently, the sample with flash coating had a smaller HE index than the sample without flash coating. These results suggest that a thin Zn-flash coating could be an effective technical strategy for mitigating HE in advanced high-strength steels.

• 대한조선학회논문집
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• 제46권3호
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• pp.279-289
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• 2009

For a Product Oil Carrier, longitudinal bulkhead as well as transverse one is corrugated shape in general and intersection part of bulkheads is utilized for a pipe trunk. Since lower and upper stools are to be connected with all of longitudinal and transverse bulkheads, they have a uniform height respectively. The purpose of this study is the development of design system for the minimization of total weight of longitudinal and transverse bulkheads at the initial design stage. In this study, the beam element models for longitudinal and transverse corrugated bulkheads are established and they are applied to the structural analysis. For the practical design, the selection and the position of an additional pipe trunk are considered in this study. In addition the required minimum distance between the bracket installed along the web of corrugation at lower stool and the diaphragm is taken into consideration during optimization process. Evolution strategy(ES) is adopted as an optimization technique.

• Journal of Microbiology
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• 제41권2호
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• pp.169-173
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• 2003

A treatability investigation was conducted to determine if landfarming would be effective for the remediation of unsanitary landfill waste soils. Calculations based on biodegradable organic carbon contents and initial CO$_2$ evolution rates revealed that landfarming has a high potential for landfill site remediation and that the optimum strategy for bioremediation is site-specific.

• 한국재료학회지
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• 제33권10호
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• pp.377-384
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• 2023

Exploring earth-abundant, highly effective and stable electrocatalysts for electrochemical water splitting is urgent and essential to the development of hydrogen (H₂) energy technology. Iron-cobalt layered double hydroxide (FeCo-LDH) has been widely used as an electrocatalystfor OER due to its facile synthesis, tunable components, and low cost. However, LDH synthesized by the traditional hydrothermal method tends to easily agglomerate, resulting in an unstable structure that can change or dissolve in an alkaline solution. Therefore, studying the real active phase is highly significant in the design of electrochemical electrode materials. Here, metal-organic frameworks (MOFs) are used as template precursors to derive FeCo-LDH from different iron sources. Iron salts with different anions have a significant impact on the morphology and charge transfer properties of the resulting materials. FeCo-LDH synthesized from iron sulfate solution (FeCo-LDH-SO₄) exhibits a hybrid structure of nanosheets and nanowires, quite different from other electrocatalysts that were synthesized from iron chloride and iron nitrate solutions. The final FeCo-LDH-SO₄ had an overpotential of 247 mV with a low Tafel-slope of 60.6 mV dec^-1 at a current density of 10 mA cm^-2 and delivered a long-term stability of 40 h for the OER. This work provides an innovative and feasible strategy to construct efficient electrocatalysts.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2008년도 연합학회학술대회
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• pp.477-486
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• 2008

This paper examines the evolution issues of regional tourism resources in complicated and networked industry the perspective of co-evolution types and dualism. Regional tourism structure has been changing more and faster according to various attractions and internal and external environment; natural resources, facilities, festivals and events, drama and movies, and public resources, etc. This paper approaches Olikowski's dualism perspective as a theoretical view about the alliance network between region's attractions and tourism industry in Korea. Exploratory analysis was explained the dualism cases performed on the matrix between resource characteristics and alliance complexity on human resources based on regional tourism industry.

• Journal of Information Technology Applications and Management
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• 제16권3호
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• pp.87-100
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• 2009

The purpose of this study is to investigate the evolution of regional tourism resources from the perspective of business ecosystem network. A regional tourism structure changes due to various factors such as natural resources, facilities, festivals and events, public resources, and etc. An exploratory analysis was conducted to examine the interaction between resource characteristics and alliance complexity in the regional tourism industry. In the process, the duality of technology provides an insight into the interaction among several players within an alliance network which include regional attractions and tourism industry. As a result. we identified four types of tourism alliance network: functional, organizational, resource-oriented, and artificially-allied. The managerial implications are also discussed.