• International Journal of Control, Automation, and Systems
• /
• v.1 no.1
• /
• pp.101-110
• /
• 2003

This paper introduces an identification method for nonlinear models in the form of rule-based Fuzzy-Neural Networks (FNN). In this study, the development of the rule-based fuzzy neural networks focuses on the technologies of Computational Intelligence (CI), namely fuzzy sets, neural networks, and genetic algorithms. The FNN modeling and identification environment realizes parameter identification through synergistic usage of clustering techniques, genetic optimization and a complex search method. We use a HCM (Hard C-Means) clustering algorithm to determine initial apexes of the membership functions of the information granules used in this fuzzy model. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are then adjusted using the identification algorithm of a GA hybrid scheme. The proposed GA hybrid scheme effectively combines the GA with the improved com-plex method to guarantee both global optimization and local convergence. An aggregate objective function (performance index) with a weighting factor is introduced to achieve a sound balance between approximation and generalization of the model. According to the selection and adjustment of the weighting factor of this objective function, we reveal how to design a model having sound approximation and generalization abilities. The proposed model is experimented with using several time series data (gas furnace, sewage treatment process, and NOx emission process data from gas turbine power plants).

• KIEAE Journal
• /
• v.14 no.4
• /
• pp.19-26
• /
• 2014

The building section is providing immediate causes for global climate change problems since it takes about 50% of carbon emission, 20~50% of waste discharge, 33% of energy consumption, 40% of resource use, and 17% of water consumption. So, many countries over the world have developed and implemented green building certification systems to assess sustainable performances of buildings since the early 1990s. In korea, the green building certification system to induce the diffusion of sustainable buildings was first introduced in 2002 and developed as an improved version of the G-SEED(Green Standard for Energy and Environmental Design) system in 2013 after major revisions of related legislations. This research conducts a survey targeting residents on an apartment building that was certified as green building and examines the importance of assessment criteria on apartment buildings to certify green buildings using the Analytic Hierarchy Process(AHP) method. And it proposes a new direction on certification assessment standards from the resident's prospective. As a result, assessment criteria such as indoor environment, ecological environment, energy & environment pollution, and maintenance management among 7 main ones turned out important on assessing the G-SEED system for apartment buildings, while criteria such as material & resource, water circulation management, and land use & transportation did relatively unimportant.

• Membrane Journal
• /
• v.27 no.4
• /
• pp.291-312
• /
• 2017

Seawater desalination is currently considered to be one of the primary technologies to resolve the global water scarcity problem. A basic understanding of membrane filtration phenomena is significant not only for further technological development but also for integrated design, optimal control, and long-term maintenance. In this vein, the present work reviews the major transport and filtration models, specifically related to reverse osmosis phenomena, provides theoretical insights based on statistical mechanics, and discusses model-based physical meanings as related to their practical implications.

• Nuclear Engineering and Technology
• /
• v.49 no.2
• /
• pp.434-441
• /
• 2017

Containment venting is one of several essential measures to protect the integrity of the final barrier of a nuclear reactor during severe accidents, by which the uncontrollable release of fission products can be avoided. The authors seek to develop an optimization approach to venting operations, from a simulation-based perspective, using an integrated severe accident code, THALES2/KICHE. The effectiveness of the containment-venting strategies needs to be verified via numerical simulations based on various settings of the venting conditions. The number of iterations, however, needs to be controlled to avoid cumbersome computational burden of integrated codes. Bayesian optimization is an efficient global optimization approach. By using a Gaussian process regression, a surrogate model of the "black-box" code is constructed. It can be updated simultaneously whenever new simulation results are acquired. With predictions via the surrogate model, upcoming locations of the most probable optimum can be revealed. The sampling procedure is adaptive. Compared with the case of pure random searches, the number of code queries is largely reduced for the optimum finding. One typical severe accident scenario of a boiling water reactor is chosen as an example. The research demonstrates the applicability of the Bayesian optimization approach to the design and establishment of containment-venting strategies during severe accidents.

• Journal of architectural history
• /
• v.8 no.3 s.20
• /
• pp.75-89
• /
• 1999

Under the WTO system, global standardization of professionalism in architecture practice calls for transformation of curriculum in architectural education in Korea. This paper compares the curriculum standards of international accrediting authorities such as NAAB and RIBA based on UIA accord which defines fundamental knowledge and abilities of an architect. As a result this paper extracts 51 achievement oriented criteria of architectural education in Korea. It can be categorized as communication, design, cultural context(history and theory, human behavior and social aspects), technical systems(structural systems, environmental control systems, construction material and assemblies) and practice(project process, project economics and business management, laws and regulations). Based on this recommended Korean curriculum standards, current curriculum is analyzed focusing on the 5 architectural programs in Seoul. Through this analysis, it became clear that some area - social and economic aspects in architecture, sustainability in architecture, understanding and selection of construction material, assemblies and environmental control system, recycling of existing building, professional liability, professional rules of conduct, project economics and project management - need to be covered and emphasized to meet the international standards in professional education in architecture. The result in this paper will be used as a basic data in the process of finding the direction of restructuring curriculum for professional architectural education in Korea.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.2
• /
• pp.25-33
• /
• 2010

Collision between vessels may lead to structural damage and penetration of hulls. The structural damage of a hull may eventually bring about global collapse of the hull girder and outflow of oil, which would contaminate seawater. Therefore, various regulations require the strength of a vessel after collision to satisfy given criteria, and owners usually request collision analyses to confirm the structural safety of their vessels. In the process of designing a vessel to satisfy the collision strength criteria, the strength has been assessed mostly by conducting collision analyses using numerical techniques, such as dynamic, non-linear, finite-element analysis. Design is an inherently iterative process during which many changes are necessary due to the endless needs for reinforcement and modification. Numerical techniques are not adequate for coping with a situation in which collision analysis is frequently required to provide the revised results that reflect the repetitive changes in designs. Numerical techniques require a lot of time and money to conduct in spite of recent improvements in computing power and in the productivity of modeling tools. Therefore, in this paper, an analytical technique is introduced and a collision problem is idealized and simplified using reasonable assumptions based on appropriate background. The technique was applied to an example of an actual FPSO and verified by comparing the results with results from the numerical technique. A good correlation was apparent between the results of the analytical and numerical techniques.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.4
• /
• pp.272-276
• /
• 2020

This paper presents an optimization process for a catamaran hull form. The entire optimization process was managed using the CAD-CFD integration platform CAESES. The resistance of the demi-hull was simulated in calm water using the CFD solver STAR-CCM+, and an inviscid fluid model was used to reduce the computing time. The Free-Form Deformation (FFD) method was used to make local changes in the bulbous bow. For the optimization of the bulbous bow, the Non-dominated Sorting Genetic Algorithm (NSGA)-II was applied, and the optimization variables were the length, breadth, and angle between the bulbous bow and the base line. The Lackenby method was used for global variation of the bow of the hull. Nine hull forms were generated by moving the center of buoyancy while keeping the displacement constant. The optimum bow part was selected by comparing the resistance of the forms. After obtaining the optimum demi-hull, the distance between two demi-hulls was optimized. The results show that the proposed optimization sequence can be used to reduce the resistance of a catamaran in calm water.

• Journal of Distribution Science
• /
• v.14 no.7
• /
• pp.21-31
• /
• 2016

Purpose - With globalization, medical tourism has developed as a new industry, which attracts practitioners and academics to have more interest in researches on customers' behavior. This research was to investigate empirically WOM effects on the intention of Chinese customers when they select an international medical tourism destination. Interestingly, WOM effects on their choice and decision process may vary by the extent of their severity of illness. Research design, data, and methodology - The data was collected from 1,747 potential Chinese residents in main districts of China. Moderated regression analysis was used to estimate WOM effects on Chinese customers' choice intention. Results - Results imply that WOM determinants of tie strength, credibility, and vividness do interact with medical tourism information and affect customers' intention for health care abroad. Results also reveal that the severity of illness plays a critical moderating role in customers' decision process. Conclusions - WOM and the severity of illness are important moderators for Chinese customers to make a decision for medical tourism. It provides some implications for service organizations for developing and implementing marketing strategies in international health care markets.

• Journal of Distribution Science
• /
• v.18 no.10
• /
• pp.53-64
• /
• 2020

Purpose: With the emergence of high technology in China, online shopping distribution of fresh agricultural products have been developing rapidly. This study built a model to investigate how perceived quality of products and logistic services, perceived risk, and perceived cost affect intention to buy fresh agricultural products in an Internet environment. Especially, in the purchasing process, attitude may work as an important mediator. Research design, data and methodology: To achieve the objectives of this study, Chinese respondents were asked to fill in a questionnaire through the China online survey website. With 520 available data, regression analysis was used to test the hypotheses. Results: Results indicate that perceived quality of fresh agriculture products and perceived logistics service quality have a significant positive impact on attitude and purchase intention. Results also reveal that perceived risk and perceived cost affect attitude and purchase intention negatively. Finally, results imply that attitude has a positive effect on purchase intention, which is the unique mediator in the online shopping process. Conclusions: This study suggests that managers in the online shopping distributions of fresh agricultural products should improve the quality of products and logistics services along with the reduction of the perceived risk and cost to compete in the China market.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.4
• /
• pp.69-79
• /
• 2013

A system of tracking a vehicle collects the vehicle location and then transmits the data into a GIS server in order to provide several service areas. An ODU built in the vehicle savesa GPS information data and communicates with the RSU installed in the road over the wave technology. The collected data in RSU is transmitted into the GIS serverand is stored. The system based on the collected GPS data in each vehicle is providing useful and various services between RSU and OBU. In this paper indicates that the system is designed in 2 phasesbased on the collected GPS data. The result comparing to process of GPS data created in 1 phase and 2 phase over the Web GIS service indicates that the capability of process of the GPS data in 2 phase is enhanced in "50.88% ~ 51.81%". Therefore, when the accident is happened the system of tracking the vehicle over GPS tech not only receives the information properly but also provides the emergence rescue services.