• Structural Engineering and Mechanics
• /
• v.50 no.2
• /
• pp.151-161
• /
• 2014

In this paper, fuel tank of the locomotive ER 24 has been studied. Firstly the behavior of fuel and air during the braking time has been investigated by using a two-phase model. Then, the distribution of pressure on the surface of baffles caused by sloshing has been extracted. Also, the fuel tank has been modeled and analyzed using Finite Element Method (FEM) considering loading conditions suggested by the DIN EN 12663 standard and real boundary conditions. In each loading condition, high stressed areas have been identified. By comparing the distribution of pressure caused by sloshing phenomena and suggested loading conditions, optimization of the tank has been taken into consideration. Moreover, internal baffles have been investigated and by modifying their geometric properties, search of the design space has been done to reach the optimal tank. Then, in order to reduce the mass and manufacturing cost of the fuel tank, Non-dominated Sorting Genetic Algorithm (NSGA-II) and Artificial Neural Networks (ANNs) have been employed. It is shown that compared to the primary design, the optimized fuel tank not only provides the safety conditions, but also reduces mass and manufacturing cost by %39 and %73, respectively.

• Journal of the Society of Naval Architects of Korea
• /
• v.52 no.4
• /
• pp.298-304
• /
• 2015

Shipboard equipment in naval ships should be designed to be safe under the shock load. Very high stress due to the shock load can be effectively reduced by the resilient mounts considering the mount capacity and dynamic characteristics. An optimum arrangement of resilient mount installed to absorb the shock energy is addressed to assess the safety of ship structure and shipboard equipment subjected to the shock load. Structural responses are analyzed for both frame structure supporting the shipboard equipment subject to the shock load with and without the resilient mounts. The shock absorbability of the resilient mount is evaluated by the results of structural response analysis; meanwhile, several types of shock analyses considering the arrangement of resilient mounts are carried out and the shock responses are compared to verify the effect of the arrangement. Thereafter, optimum arrangements are obtained by means of Genetic algorithm (GA) considering the different capacities of resilient mount. Stress, deformation and dynamic feature at the frame structure supporting the shipboard equipment under the shock load are also discussed in order to meet the capacity of resilient mount.

• Clinical and Experimental Pediatrics
• /
• v.57 no.9
• /
• pp.384-395
• /
• 2014

Febrile seizure (FS) is the most common seizure disorder of childhood, and occurs in an age-related manner. FS are classified into simple and complex. FS has a multifactorial inheritance, suggesting that both genetic and environmental factors are causative. Various animal models have elucidated the pathophysiological mechanisms of FS. Risk factors for a first FS are a family history of the disorder and a developmental delay. Risk factors for recurrent FS are a family history, age below 18 months at seizure onset, maximum temperature, and duration of fever. Risk factors for subsequent development of epilepsy are neurodevelopmental abnormality and complex FS. Clinicians evaluating children after a simple FS should concentrate on identifying the cause of the child's fever. Meningitis should be considered in the differential diagnosis for any febrile child. A simple FS does not usually require further evaluation such as ordering electroencephalography, neuroimaging, or other studies. Treatment is acute rescue therapy for prolonged FS. Antipyretics are not proven to reduce the recurrence risk for FS. Some evidence shows that both intermittent therapy with oral/rectal diazepam and continuous prophylaxis with oral phenobarbital or valproate are effective in reducing the risk of recurrence, but there is no evidence that these medications reduce the risk of subsequent epilepsy. Vaccine-induced FS is a rare event that does not lead to deleterious outcomes, but could affect patient and physician attitudes toward the safety of vaccination.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.10
• /
• pp.5078-5094
• /
• 2019

In recent years, the development of drone technologies has promoted the widespread commercial application of drones. However, the ability of drone to carry explosives and other destructive materials may bring serious threats to public safety. In order to reduce these threats from illegal drones, acoustic feature extraction and classification technologies are introduced for drone sound identification. In this paper, we introduce the acoustic feature vector extraction method of harmonic line association (HLA), and subband power feature extraction based on wavelet packet transform (WPT). We propose a feature vector extraction method based on combined HLA and WPT to extract more sophisticated characteristics of sound. Moreover, to identify drone sounds, support vector machine (SVM) classification with the optimized parameter by genetic algorithm (GA) is employed based on the extracted feature vector. Four drones' sounds and other kinds of sounds existing in outdoor environment are used to evaluate the performance of the proposed method. The experimental results show that with the proposed method, identification probability can achieve up to 100 % in trials, and robustness against noise is also significantly improved.

• Journal of environmental and Sanitary engineering
• /
• v.4 no.2 s.7
• /
• pp.33-45
• /
• 1989

The survey was conducted on the actual conditions of species, the facilities, a establishment of regulation concerning laboratory animals and the related problems on users and suppliers of laboratory animals in Korea. The questionnaires were sent to 430 and received from 107$(24.9\%)$ places. The results obtained were as follows : 1. Experimental animals used at the 107 places were 21 species: mouse(90\;places,\;84.1\%)$, rat $(61,\;57.0\%)$, rabbit$(76,\;71.0\%)$, guineapig$(42,\; 39.3\%)$ etc. 2. The main organizations using laboratory animals were university $46(43.0\%)$, institute $32(29.9\%)$ and pharmaceutical company $27(25.2\%)$ etc. 3. Most the laboratory animal facilities in Korea have been conventional system without environmental controls, but a few places have been recently established barrier system. 4. To get a good experimental result, a regular genetic and microbiological monitoring of laboratory animals should be done. 5. It was required that a educational facilities and a quality test agency for laboratory animals should be established. 6. It was also required that a regulation for breeding and using of laboratory animals should 'be enacted.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.397-400
• /
• 2011

MDO Optimization for a low pressure axial compressor rotor has been carried out to improve aerodynamic performance and structural stability. Global optimized solution was obtained from an artificial neural network model with genetic algorithm. Optimized rotor model has a high blade loading near hub and near zero incidence flow angle near tip region to reduce the incidence loss and flow separation at trailing edge region. Also the rotor shape is converged to a trapezoid shape to reduce the maximum stress occurred at the root of the blade. Numerical simulation results show that rotor has 87.6% rotor efficiency and safety factor over than 3.

• International Journal of Advanced Culture Technology
• /
• v.7 no.2
• /
• pp.144-150
• /
• 2019

Recently, an increasing number of urban farmers are growing fresh vegetables and fruits themselves using urban garden or weekend farms. In other words, this is called urban agriculture. After the Industrial Revolution in the 18th century, the agricultural society changed from an agricultural society to an industrial society, and the population began to flock to the cities. With the continued increase of urban population, countries with abundant capital were able to control the distribution structure of food supplies and trade agreements among countries. Since energy consumption and carbon dioxide emissions caused by agricultural product movements have emerged as the main culprits of global warming, and our table is threatened by safety due to food supply that has no genetic modification or knowledge of the cultivation process, urban agriculture is already taking hold in the West. In other words, as agriculture met cities, its role grew. Each region actively conducts agricultural activities for raising poultry as well as growing vegetables and fruits by using flower beds of detached houses in the city center, rooftops of high and low buildings, or school playgrounds and small tributaries of land. The purpose of this study is to analyze and understand the significance and type of urban agriculture and to examine the cases of domestic and foreign urban agriculture based on this and to seek the developing direction of urban agriculture, which is gradually increasing. Tired of growing competition and rapid change, urbanites are seeking health and relaxation and are planning to present development measures for urban farming and conduct follow-up research to ensure safe food.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.3 no.3
• /
• pp.129-138
• /
• 2022

Reintroduction programs have been promoted across the world to recover and rehabilitate endangered birds through ex situ captive breeding and releasing to the nature. The ultimate aims of these reintroduction programs are recovery of sustainable populations in natural habitats. To ensure the success of the reintroduction programs, it is necessary to examine the followings in order to increase the success rate of releasing along with the development of captive breeding techniques: 1) Adequate habitat provision, 2) adaptability of captive-bred individuals, 3) survivability of released individuals, and 4) social interest and will. Before releasing captive-bred individuals, it should be reviewed whether there are habitats in which the limiting factor is removed, and assessed their long-term safety. The quantity and quality of the released individuals must be considered to increase the chances for mate selection, maintain genetic diversity, and acquire the ability to adapt to the wild. The release method must be decided in consideration of characteristics of the target habitats and individuals, and rational means such as careful observation, evaluation, and feedback must be provided throughout the release process. For the long-term success of recovery projects, social awareness, sustainable support, and related experts are needed. Satisfying these criteria can help to increase the success rates of reintroduction programs. For the bird reintroduction program in the future, the feasibility of the methods and procedures must be closely reviewed before starting.

• ETRI Journal
• /
• v.44 no.4
• /
• pp.641-653
• /
• 2022

In the process of autonomous vehicle motion planning and to create comfort for vehicle occupants, factors that must be considered are the vehicle's safety features and the road's slipperiness and smoothness. In this paper, we build a mathematical model based on the combination of a genetic algorithm and a neural network to offer lane-change solutions of autonomous vehicles, focusing on human vehicle control skills. Traditional moving planning methods often use vehicle kinematic and dynamic constraints when creating lane-change trajectories for autonomous vehicles. When comparing this generated trajectory with a man-generated moving trajectory, however, there is in fact a significant difference. Therefore, to draw the optimal factors from the actual driver's lane-change operations, the solution in this paper builds the training data set for the moving planning process with lane change operation by humans with optimal elements. The simulation results are performed in a MATLAB simulation environment to demonstrate that the proposed solution operates effectively with optimal points such as operator maneuvers and improved comfort for passengers as well as creating a smooth and slippery lane-change trajectory.

• Microbiology and Biotechnology Letters
• /
• v.50 no.4
• /
• pp.465-476
• /
• 2022

The importance of beneficial microorganisms, particularly probiotics, that coexist in the human body, is being increasingly recognized. Probiotics are representative health functional foods that provide health benefits to humans through the production of various metabolites, including short-chain fatty acids. However, the health benefits are strain-specific, and the use of each probiotic strain should follow guidelines that assure its safety. Accurate identification of the strain should be managed through genetic and phenotypic analyses of the strain. Besides, the functionality of probiotics should be disclosed in vitro and in vivo so that they can be used as legal functional ingredients (i.e., individual standards). In this review, we deal with the guidelines, including the technical factors related to probiotic strains. The common health effects of probiotic strains include proliferation of beneficial bacteria, control of harmful bacteria, and facilitation of bowel activities. Probiotics with various functionalities (e.g., body fat and cholesterol reduction, vaginal health, and improvement of skin's immune system) have been investigated as "individual standards of raw materials for health functional foods" provided by MFDS. In the future, various biotechnologies including synthetic biology can be applied to produce customized probiotics to improve human health.