• Title/Summary/Keyword: Multi-Objectives

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Applying Multi-Response Optimization to Explore Fermentation Conditions of Probiotics (프로바이오틱 유산균 발효조건 탐색을 위한 다반응 최적화의 활용)

  • Sungsue Rheem
    • Journal of Dairy Science and Biotechnology
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    • v.41 no.2
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    • pp.45-56
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    • 2023
  • This review serves two purposes: first, to promote the use of improved optimization techniques in response surface methodology (RSM); and second, to enhance the optimum conditions for the fermentation of probiotics. According to research in dairy science, Lactiplantibacillus plantarum K79 is a candidate probiotic that has beneficial health effects, such as lowering blood pressure. The optimum conditions for L. plantarumK79 to produce peptides with angiotensin-converting enzyme (ACE) inhibitory activity were proposed, through modeling each of ACE inhibitory activity and pH as a function of the four factors that are skim milk concentration (%), incubation temperature (℃), incubation time (hours), and starter added amount (%). To estimate optimum conditions, the researchers employed a desirability-based multi-response optimization approach, utilizing third-order models with a nonsignificant lack of fit. The estimated optimum fermentation conditions for L. plantarum K79 were as follows: a skim milk concentration of 10.76%, an incubation temperature of 36.9℃, an incubation time of 23.76 hours, and a starter added amount of 0.098%. Under these conditions, the predicted ACE inhibitory activity was 91.047%, and the predicted pH was 4.6. These predicted values achieved the objectives of the multi-response optimization in this study.

A Link-Based Label Correcting Multi-Objective Shortest Paths Algorithm in Multi-Modal Transit Networks (복합대중교통망의 링크표지갱신 다목적 경로탐색)

  • Lee, Mee-Young;Kim, Hyung-Chul;Park, Dong-Joo;Shin, Seong-Il
    • Journal of Korean Society of Transportation
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    • v.26 no.1
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    • pp.127-135
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    • 2008
  • Generally, optimum shortest path algorithms adopt single attribute objective among several attributes such as travel time, travel cost, travel fare and travel distance. On the other hand, multi-objective shortest path algorithms find the shortest paths in consideration with multi-objectives. Up to recently, the most of all researches about multi-objective shortest paths are proceeded only in single transportation mode networks. Although, there are some papers about multi-objective shortest paths with multi-modal transportation networks, they did not consider transfer problems in the optimal solution level. In particular, dynamic programming method was not dealt in multi-objective shortest path problems in multi-modal transportation networks. In this study, we propose a multi-objective shortest path algorithm including dynamic programming in order to find optimal solution in multi-modal transportation networks. That algorithm is based on two-objective node-based label correcting algorithm proposed by Skriver and Andersen in 2000 and transfer can be reflected without network expansion in this paper. In addition, we use non-dominated paths and tree sets as labels in order to improve effectiveness of searching non-dominated paths. We also classifies path finding attributes into transfer and link travel attribute in limited transit networks. Lastly, the calculation process of proposed algorithm is checked by computer programming in a small-scaled multi-modal transportation network.

The relationship between emotional intelligence and cultural competency of dental hygiene students (치위생(학)과 학생의 감성지능과 문화 역량과의 관련성)

  • Park, Min-Seon;Jang, Jong-Hwa
    • Journal of Korean society of Dental Hygiene
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    • v.18 no.3
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    • pp.385-397
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    • 2018
  • Objectives: The study was a cross-sectional research to examine dental hygiene students' multi-cultural experiences, emotional intelligence and cultural competency and to understand the correlations among them. Methods: The study was conducted from September $1^{st}$ to October $31^{st}$ 2016, based on the survey of 449 students in the department of dental hygiene at 7 Universities. The questionnaire consisted of 57 questions including general characteristics (n=7), multi-cultural experiences (n=7), emotional intelligence (n=16) and cultural competency (n=27). Results: Each score of students' emotional intelligence and cultural competency is 3.43 and 3.01 respectively in 5-point scale. An analysis of correlations between emotional intelligence and cultural competency shows that the higher the emotional intelligence, the higher the cultural competency (r=0.342). The factors affecting the cultural competency include use of emotions (${\beta}=0.327$, p<0.001), control of emotions (${\beta}=0.254$, p=0.001), frequency of multi-cultural media (${\beta}=0.221$, p<0.001) and experience of multi-cultural class (${\beta}=0.221$, p=0.002). The modified explanatory power in this model is 28.2% (F=10.856, p<0.001). Conclusions: There was a positive correlation between emotional intelligence and cultural competency, and the contacts with multi-culture and experience of class are identified as the affecting factors. Dental hygiene students should acquire theoretical experiences regarding the multi-culture through curriculum or continuous educations and it is necessary to promote such educations in order to develop and apply the programs for the enhancement of emotional intelligence.

Evolutionary Multi-Objective Optimization Algorithms for Uniform Distributed Pareto Optimal Solutions (균일분포의 파레토 최적해 생성을 위한 다목적 최적화 진화 알고리즘)

  • Jang Su-Hyun;Yoon Byungjoo
    • The KIPS Transactions:PartB
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    • v.11B no.7 s.96
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    • pp.841-848
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    • 2004
  • Evolutionary a1gorithms are well-suited for multi-objective optimization problems involving several, often conflicting objectives. Pareto-based evolutionary algorithms, in particular, have shown better performance than other multi-objective evolutionary algorithms in comparison. However, generalized evolutionary multi-objective optimization algorithms have a weak point, in which the distribution of solutions are not uni-formly distributed onto Pareto optimal front. In this paper, we propose an evolutionary a1gorithm for multi-objective optimization which uses seed individuals in order to overcome weakness of algorithms Published. Seed individual means a solution which is not located in the crowded region on Pareto front. And the idea of our algorithm uses seed individuals for reproducing individuals for next generation. Thus, proposed a1go-rithm takes advantage of local searching effect because new individuals are produced near the seed individual with high probability, and is able to produce comparatively uniform distributed pareto optimal solutions. Simulation results on five testbed problems show that the proposed algo-rithm could produce uniform distributed solutions onto pareto optimal front, and is able to show better convergence compared to NSGA-II on all testbed problems except multi-modal problem.

A Multi-Objective Shortest Paths Finding Considering Multi-Class in A Multi-Modal Transit Network for Providing User-Customized Route Information (사용자 맞춤형 대중교통 경로정보제공을 위한 다계층의 다목적 경로탐색기법 연구)

  • Lee, Mee-Young;Park, Je-Jin;Jeong, Jeom-Rae;Park, Dong-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.3
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    • pp.1-14
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    • 2008
  • Mass transit information should contribute many benefits to users. Especially transportation information technology is developing highly with information technology in Korea recently. Hereafter it is expected to provide customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithms in public transportation networks including travel and transfer attributes. In this research, multi objectives such as travel time, transfer time, and number of transfer and so on are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding alternatives arbitrarily is proposed by selecting the best alternative which provides maximum utility to users among non dominated paths. Therefore, the ultimate goal of this study proposes a multi objective shortest paths finding algorithm which can take into account multiple user classes in a transit network with multiple travel modes. The proposed algorithm is demonstrated based on the two case studies - a small toy network and the large-scaled Seoul Metropolitan subway network.

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Application of a Multiobjective Technique for Optimum Operation of Pumps and Reservoirs in Service Water Transmission Systems (다목적 분석 기법을 이용한 상수도 송수계의 펌프와 배수지의 연계 최적 운영)

  • Ko, Seok-Ku;Oh, Min-Hwan
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.738-743
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    • 1991
  • A multiobjective analysis technique was applied for the optimum operation of pumps and reservoirs in service water transmission systems. Three major objectives were identified and assessed on the normally operating service water transmission systems. They are, 1) stability of pump operation; 2) economic point of view in minimizing the energy cost for pumping; 3) reliability in meeting the stochasticaly varying demands. The measures of these objectives were required times of pump on-offs in stability, required total energy cost in economics, and minimum required storage during the operating horizon in reliability. In order to find the best meeting solution to the decision maker, a set of non-dominated solutions which show the tradeoff relationships between the considering objectives were generated. The DM selects the best solution from this explicit tradeoff relationships using his heuristic decision rules or experience. The theory was verified by applying to the Kumi Service Water System. A combined technique of the ${\varepsilon}-constraint$ and the weighting methods was used to generate the nondominated solutions, and the dynamic programming algorithm was applied to find the optimal solution for the discretized multi-objective analysis problems.

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Autism Spectrum Disorder and Savant Syndrome: A Systematic Literature Review

  • Hyun Ok Park
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.34 no.2
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    • pp.76-92
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    • 2023
  • Objectives: This study aimed to analyze research trends in autism spectrum disorder (ASD) and savant syndrome and their cognitive characteristics through a systematic literature review. The objectives of this study were to establish an overview of research trends in ASD and savant syndrome, analyze the overall characteristics of individuals with ASD and savant syndrome, and examine their cognitive characteristics. Methods: For the systematic literature review, three criteria were used to select review articles: 1) literature from peer-reviewed journals, published in the past 15 years, from 2008 to 2022; 2) subjects with ASD and savant syndrome; 3) study objectives focused on the basic phenomenon and cognitive characteristics of ASD and savant syndrome. Finally, based on the selection criteria, a total of 40 articles were included. Results: Five themes and nine subthemes were derived from the analysis of 40 studies. The five main themes were as follows: 1) What is savant syndrome? 2) Demographic characteristics of savant syndrome; 3) Spectra of savant syndrome; 4) Savant syndrome and ASD; and 5) Cognitive characteristics of ASD with savant syndrome. The subthemes of the cognitive characteristics were weak central coherence, detail-focused cognitive processing, enhanced perceptual functioning, and hyper-systemizing. Conclusion: Several studies have been conducted to understand ASD and savant syndrome; however, no single theory can specify the cognitive characteristics of people with ASD and savant syndrome. Therefore, further systematic and multi-layered research on ASD and savant syndrome are required for more comprehensive results.

Optimal sustainable design of steel-concrete composite footbridges considering different pedestrian comfort levels

  • Fernando L. Tres Junior;Guilherme F. Medeiros;Moacir Kripka
    • Steel and Composite Structures
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    • v.51 no.6
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    • pp.647-659
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    • 2024
  • Given the increased interest in enhancing structural sustainability, the current study sought to apply multiobjective optimization to a footbridge with a steel-concrete composite I-girder structure. It was considered as objectives minimizing the cost for building the structure, the environmental impact assessed by CO2 emissions, and the vertical accelerations created by human-induced vibrations, with the goal of ensuring pedestrian comfort. Spans ranging from 15 to 25 meters were investigated. The resistance of the slab's concrete, the thickness of the slab, the dimensions of the welded steel I-profile, and the composite beam interaction degree were all evaluated as design variables. The optimization problem was handled using the Multiobjective Harmony Search (MOHS) metaheuristic algorithm. The optimization results were used to generate a Pareto front for each span, allowing us to assess the correlations between different objectives. By evaluating the values of design variables in relation to different levels of pedestrian comfort, it was identified optimal values that can be employed as a starting point in predimensioning of the type of structure analyzed. Based on the findings analysis, it is possible to highlight the relationship between the structure's cost and CO2 emission objectives, indicating that cost-effective solutions are also environmentally efficient. Pedestrian comfort improvement is especially feasible in smaller spans and from a medium to a maximum level of comfort, but it becomes expensive for larger spans or for increasing comfort from minimum to medium level.

Application of Surrogate Modeling to Design of A Compressor Blade to Optimize Stacking and Thickness

  • Samad, Abdus;Kim, Kwang-Yong
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.1
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    • pp.1-12
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    • 2009
  • Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.

Efficient resource allocation mechanisms for large organizations

  • Kim, Hyung-Kee
    • Journal of the Korean Operations Research and Management Science Society
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    • v.1 no.1
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    • pp.127-138
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    • 1976
  • Economists have become interested in the centralization and decentralization of planning, in the linking up of models into a homogenous model system, and in multi-level planning. In this study, Input/Output techniques used for explaining the resource allocation mechanisms to be more rational through detailed specifications of a large organization's objectives and explicit linking of centralization and decentralization to such objectives. Also the application of mathematical methods to the higher levels of planning in the optimal allocation resources can't fully describe the actual practice of planning. On the other hand, 1-0 techniques are standard in economic analysis and planning. However, the application procedures to the armed forces hold only when their assumptions are met and when their solutions are convergent. So, it is of limited applicability.

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