• Title/Summary/Keyword: Exploration & Exploitation

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Hybrid artificial bee colony-grey wolf algorithm for multi-objective engine optimization of converted plug-in hybrid electric vehicle

  • Gujarathi, Pritam K.;Shah, Varsha A.;Lokhande, Makarand M.
    • Advances in Energy Research
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    • v.7 no.1
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    • pp.35-52
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    • 2020
  • The paper proposes a hybrid approach of artificial bee colony (ABC) and grey wolf optimizer (GWO) algorithm for multi-objective and multidimensional engine optimization of a converted plug-in hybrid electric vehicle. The proposed strategy is used to optimize all emissions along with brake specific fuel consumption (FC) for converted parallel operated diesel plug-in hybrid electric vehicle (PHEV). All emissions particulate matter (PM), nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) are considered as optimization parameters with weighted factors. 70 hp engine data of NOx, PM, HC, CO and FC obtained from Oak Ridge National Laboratory is used for the study. The algorithm is initialized with feasible solutions followed by the employee bee phase of artificial bee colony algorithm to provide exploitation. Onlooker and scout bee phase is replaced by GWO algorithm to provide exploration. MATLAB program is used for simulation. Hybrid ABC-GWO algorithm developed is tested extensively for various values of speeds and torque. The optimization performance and its environmental impact are discussed in detail. The optimization results obtained are verified by real data engine maps. It is also compared with modified ABC and GWO algorithm for checking the effectiveness of proposed algorithm. Hybrid ABC-GWO offers combine benefits of ABC and GWO by reducing computational load and complexity with less computation time providing a balance of exploitation and exploration and passes repeatability towards use for real-time optimization.

The Impact of Existing Relationship and IT-based collaboration activities on the Performance of Supply chain: Focused on Absorptive Capacity (공급 사슬 참여 기업간 기존 거래 관계와 IT 기반 협업 활동이 공급 사슬 성과에 미치는 영향: 흡수 역량을 중심으로)

  • Lee, Won Jun;Bock, Gee-Woo;Kang, Youn Jung
    • Knowledge Management Research
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    • v.19 no.4
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    • pp.77-98
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    • 2018
  • The purpose of this paper is examine the existing relations structure and IT use for collaboration activities on supply chain and their impacts on the performance of supply chain. This study made a design of the research model that was further constructed by integrating the relationship structure, IT exploration, IT exploitation, supply chain collaboration, absorptive capacity, and knowledge creation, efficiency and efficient. The survey data were collected from 378 companies, where firms are facing increased global competitive pressure and heavily utilize SCM to retain their competitive advantages. The authors validated a measurement model with structural equation modelling and tested eight hypotheses. As a result, the absorptive capacity was closely related to trust, IT exploitation and IT exploration, but supply chain collaboration. Examining the effect of supply chain collaboration with two types of absorptive capacity, the authors found positive effect on potential absorptive capacity, but a non-significant effect on realized absorptive capacity. This finding suggests that the improving performance of supply chain not only is related to the relations structure and IT use on supply chain, but also is closely related to the absorptive capacity.

Relationship Between Innovation Activities and Business Performance: A Case Study in Indonesia

  • ARIF, Muhammad Ridwan;HASAN, Dahsan
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.4
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    • pp.307-315
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    • 2021
  • The study aims to investigate the relationship between innovation activities and business process performance in higher education institution (hereinafter referred to as "HEI") context. The data was collected using a survey and later analyzed through Partial Least Squares Structural Equation Modelling (PLSSEM) and SmartPLS software. A total of 50 questionnaires were submitted from respondents representing vocational study program management located in Makassar, Indonesia. The findings show that two hypotheses discussed in this study fit the empirical data. Specifically, the results show that there is a positive relationship between innovation activities and business process performance, involving two types of innovation activities, which are exploration activities and exploitation activities, within HEIs. Explorative activity is firmly related to exploitative activity, which furthermore links to business process performance within the HEIs observed. The results confirm that exploration activity can stimulate and lead the HEIs management to generate exploitation activity. For instance, capabilities to absorb knowledge from the external institution may lead this institution to generate advanced academic processes, as well as more efficient and effective managerial processes. The study also signifies ambidexterity capacity, suggesting that it may lead HEIs management to formulate proper strategies in achieving better performance and gaining competitive advantage.

PESA: Prioritized experience replay for parallel hybrid evolutionary and swarm algorithms - Application to nuclear fuel

  • Radaideh, Majdi I.;Shirvan, Koroush
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3864-3877
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    • 2022
  • We propose a new approach called PESA (Prioritized replay Evolutionary and Swarm Algorithms) combining prioritized replay of reinforcement learning with hybrid evolutionary algorithms. PESA hybridizes different evolutionary and swarm algorithms such as particle swarm optimization, evolution strategies, simulated annealing, and differential evolution, with a modular approach to account for other algorithms. PESA hybridizes three algorithms by storing their solutions in a shared replay memory, then applying prioritized replay to redistribute data between the integral algorithms in frequent form based on their fitness and priority values, which significantly enhances sample diversity and algorithm exploration. Additionally, greedy replay is used implicitly to improve PESA exploitation close to the end of evolution. PESA features in balancing exploration and exploitation during search and the parallel computing result in an agnostic excellent performance over a wide range of experiments and problems presented in this work. PESA also shows very good scalability with number of processors in solving an expensive problem of optimizing nuclear fuel in nuclear power plants. PESA's competitive performance and modularity over all experiments allow it to join the family of evolutionary algorithms as a new hybrid algorithm; unleashing the power of parallel computing for expensive optimization.

The effect of ambidextrous strategic balance on the management performance of venture businesses (양손잡이 전략균형이 벤처기업 경영성과에 미치는 영향)

  • Se-jong Yoo;Yong-seok Cho;Woo-hyoung Kim
    • Korea Trade Review
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    • v.48 no.1
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    • pp.83-126
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    • 2023
  • The revenue histogram of venture businesses is shifting from bell-shaped normal distribution to power-law distribution, which implies that the fitness landscape of the venture businesses ecosystem is changing to be more rugged terrain. We argue that the firm should adopt both exploitation (fast follower) and exploration (or first mover) strategies not to get stuck in local maxima in the rugged fitness landscape from the complex system perspective. By designing and performing agent-based modeling simulation experiments which consist of three types of agents (new technologies, entrepreneurs, and consumers), we demonstrated that the ambidexterity strategy showed the highest performance score in three of four different environment except 'Fast Widening' case where the exploitation strategy showed the highest performance score under low technology appropriation and fast disruptive technology development speed. By investigating the financial and other statistics of 617 top venture businesses who have earned 100B won or higher annual revenue, we concluded that 82% and 9% of firms are bent on the exploitation and exploration strategy.

A Study on the Financial System for Developing Mineral Resources and Protecting the Marine Environment in the Area (심해저 광물자원 개발과 해양환경보호를 위한 재정제도에 관한 연구)

  • Seongwook Park
    • Ocean and Polar Research
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    • v.45 no.1
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    • pp.11-22
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    • 2023
  • For the commercial development of deep-sea mineral resources, the International Seabed Authority is engaged in wide ranging discussions to establish the Regulations on Exploitation. The core issue of the Regulations on Exploitation is how to protect the marine environment along with the royalty system that distributes the profits from such development. The United Nations Convention on the Law of the Sea stipulates the protection of the marine environment in Part 12 (Articles 192-237) for the preservation of the marine environment, and in the 1994 Implementation Agreement, the protection of the marine environment at the stage of application for approval of the plan of work together with the Regulations on Exploration for the protection of the marine environment. For this purpose, certain obligations are imposed on the applicants. In the Regulations on Exploitation, financial systems such as environmental performance guarantee, insurance, and environmental compensation funds, which were not found in the Regulations on Exploration, are added to further specify the measures for marine environment protection generally stipulated in the 1982 Law of the Convention or 1994 Implementation Agreement. Regarding the financial system for marine environment protection, the Marine Environmental Protection and Conservation Informal Working Group meeting is revising the purpose of the environmental compensation fund. Among these financial system elements, it is judged that there is a possibility that the environmental performance guarantee and insurance may overlap considerably, and it is also thought that the establishment of the environmental compensation fund can also provide a substantial sum of money that will meet the purpose of the compensation fund in terms of securing its financial resources. In this paper, the question is posed as to whether or not this can be accomplished. In this respect, this paper examines the environmental performance guarantee, insurance, and environmental compensation fund, which are necessary for the protection of the marine environment of the deep seabed, but which can impose appropriate obligations on contractors for the commercial development of deep seabed mineral resources. At the same time as figuring out how it is operated in relation to relevant domestic laws, I would like to propose a plan to reflect the implications derived from the domestic law operation process in the Regulations on Exploitation.

Promoting Uncertain Exploration : A Case Study (불확실한 탐험을 촉진하는 방법 : 사례연구)

  • Ha, Seongwook
    • Knowledge Management Research
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    • v.10 no.1
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    • pp.53-70
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    • 2009
  • This study empirically explored what promotes exploration, through a case analysis of a Korean SME (small and medium sized enterprise), based on the research framework which focuses on the identification and the selection of exploratory NPD (new product development) alternatives, and the accumulation of novel capabilities in new technology domains. The learning process of the exploratory NPD project described is as follows. The identification barrier of exploratory NPD project is relatively low. Constructive crisis is germane to selecting exploratory NPD alternatives and to enduring the long payback period. New separated R&D unit is likely to implement the exploratory NPD project. The length of the gestation period of the exploratory NPD project is related with the level of the conflict between old members and new members. This study identified several antecedents of the exploratory NPD project. Prior success promotes the identification process of the exploratory NPD projects. Constructive crisis is related with CEO's personal characteristics such as future oriented and proactive personality. The proactive involvement and persuasion of CEO are germane to reducing the conflict between old and new members and to the success of the exploratory NPD project. Based on the results, this study discusses several implications and future research directions.

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Effects of Latin hypercube sampling on surrogate modeling and optimization

  • Afzal, Arshad;Kim, Kwang-Yong;Seo, Jae-won
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.3
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    • pp.240-253
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    • 2017
  • Latin hypercube sampling is widely used design-of-experiment technique to select design points for simulation which are then used to construct a surrogate model. The exploration/exploitation properties of surrogate models depend on the size and distribution of design points in the chosen design space. The present study aimed at evaluating the performance characteristics of various surrogate models depending on the Latin hypercube sampling (LHS) procedure (sample size and spatial distribution) for a diverse set of optimization problems. The analysis was carried out for two types of problems: (1) thermal-fluid design problems (optimizations of convergent-divergent micromixer coupled with pulsatile flow and boot-shaped ribs), and (2) analytical test functions (six-hump camel back, Branin-Hoo, Hartman 3, and Hartman 6 functions). The three surrogate models, namely, response surface approximation, Kriging, and radial basis neural networks were tested. The important findings are illustrated using Box-plots. The surrogate models were analyzed in terms of global exploration (accuracy over the domain space) and local exploitation (ease of finding the global optimum point). Radial basis neural networks showed the best overall performance in global exploration characteristics as well as tendency to find the approximate optimal solution for the majority of tested problems. To build a surrogate model, it is recommended to use an initial sample size equal to 15 times the number of design variables. The study will provide useful guidelines on the effect of initial sample size and distribution on surrogate construction and subsequent optimization using LHS sampling plan.

Optimal Exploration-Exploitation Strategies in Reinforcement Learning for Online Banner Advertising: The Impact of Word-of-Mouth Effects (온라인 배너 광고 강화학습의 최적 탐색-활용 전략: 구전효과의 영향)

  • Bumsoo Kim;Gun Jea Yu;Joonkyum Lee
    • Journal of Service Research and Studies
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    • v.14 no.2
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    • pp.1-17
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    • 2024
  • One of the most important decisions for managers in the online banner advertising industry, is to choose the best banner alternative for exposure to customers. Since it is difficult to know the click probability of each banner alternative in advance, managers must experiment with multiple alternatives, estimate the click probability of each alternative based on customer clicks, and find the optimal alternative. In this reinforcement learning process, the main decision problem is to find the optimal balance between the level of exploitation strategy that utilizes the accumulated estimated click probability information and exploration strategy that tries new alternatives to find potentially better options. In this study we analyze the impact of word-of-mouth effects and the number of alternatives on the optimal exploration-exploitation strategies. More specifically, we focus on the word-of-mouth effect, where the click-through rate of the banner increases as customers promote the related product to those around them after clicking the exposed banner, and add it to the overall reinforcement learning process. We analyze our problem by employing the Multi-Armed Bandit model, and the analysis results show that the larger the word-of-mouth effect and the fewer the number of banner alternatives, the higher the optimal exploration level of advertising reinforcement learning. We find that as the probability of customers clicking on the banner increases due to the word-of-mouth effect, the value of the previously accumulated estimated click-through rate knowledge decreases, and therefore the value of exploring new alternatives increases. Additionally, when the number of advertising alternatives is small, a larger increase in the optimal exploration level was observed as the magnitude of the word-of-mouth effect increased. This study provides meaningful academic and managerial implications at a time when online word-of-mouth and its impact on society and business is becoming more important.

Knowledge Creation Perspective on Technological Capability Accumulation of a High-tech SMEs : Comparative Case Study and Strategic Implications (중소기업(中小企業)의 선진(先導) 기술능력(技術能力) 축적과정(蓄積過程)에 관(關)한 연구(硏究) - LCD 제조(製造) 장비업체(裝備業體)를 중심(中心)으로-)

  • Lee, Pan-Gook;Chung, Dae-Yong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.4 no.3
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    • pp.1-22
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    • 2009
  • A firm's competitive capabilities become greater when the firm has a specific knowledge. There are many studies have been examined how to accumulate the firm specific knowledge and to get the competitive capability on the various perspectives. This study suggest that the conceptual framework on the absorptive capability through reviews on the knowledge management theory. And it also suggests that the proposition about the technological capability building process through the in depth case study on a small and medium sized company in a LCD industry. This study found the following major characteristics about the absorptive capability building and knowledge creating process. First, it is required to building an absorptive capability rapidly that the harmony of local capabilities, integrative capabilities, and intensity of effort. And the most important factor is the intensity of effort in a small and medium sized firm with a weak knowledge base. Second, it is required to develop an innovative new product that the utilization of expeditious learning mechanism based on the exploration and exploitation process. Finally, complementary assets are needed to proactive exploration and exploitation. Based on the findings, the theoretical and managerial implications are derives and the further research directions are proposed.

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