• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.413-421
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• 2013

Purpose: System availability and life cycle cost are often used to evaluate the system performance and is influenced by the operation and maintenance characteristic. In this paper, we propose the method to improve life cycle cost and satisfy the target availability through redundancy allocation. Methods: We consider the redundancy is available at all items in multi level system. Thus, we assume that sub-assembly, module, components can be duplicated. Simulation and genetic algorithm are employed to optimize redundancy allocation. Results: Target availability is higher, the life cycle cost is increased. In addition, the items for redundancy are selected at higher level in multi level system if target availability is higher. Conclusion: We could know that target availability affects the duplication number of items and the selection of redundancy items. For further study, we will consider new optimization algorithms to compare with the proposed GA algorithm and improve optimization performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1073-1080
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• 2011

In this study, a target detection algorithm was proposed for using hyperspectral imagery. The proposed algorithm is designed to have minimal processing time, low false alarm rate, and flexible threshold selection. The target detection procedure can be divided into two steps. Initially, candidates of target pixel are extracted using matching ratio of spectral pattern that can be calculated by spectral derivation. Secondly, spectral distance is computed only for those candidates using Euclidean distance. The proposed two-step method showed lower false alarm rate than the Euclidean distance detector applied over the whole image. It also showed much lower processing time as compared to the Mahalanobis distance detector.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.104-114
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• 1996

For the improvement of productivity, the reduction of cost and time for manufacturing is mandatory, especially in the field of electromic industry. The study is concerned with a practical means of systematic assistance to formability estimation and selection of reliable design specification for electronic sheet metal parts. The objective of this research work is to develop a simulation system which hops to analyze the target processes with the finite element method and to acquire available design data quickly and exactly. The simulation system developed in the study consists of design verification, selection of optimal combination of parameters, knowledge acquisition and graphical user interface(GUI). Design verification is automatically carried out by using the finite element method. A data base management system and nomograms are utilized for knowledge acquisition. The developed system has been applied to some major sheet metal forming operations such as flanging, embossing, bending and blanking. According to the simulated results, the validation of the target processes has been confirmend. Analysis data, estimation rules of formability and graphical representation of the analysis have been employed for the designer's understanding and evaluation, thus providing a practical means of robust design and evaluation of forma- bility for producing electronic sheet metal parts.

• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.404-410
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• 2017

In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company's Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.227-230
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• 1997

In this paper, robot navigation experiments with a new navigation algorithm are carried out in real environments. The authors already proposed a reactive navigation algorithm for mobile robots using optimal via-point selection method. At each sampling time, a number of via-point candidates is constructed with various candidates of heading angles and velocities. The robot detects surrounding obstacles, and the proposed algorithm utilizes fuzzy multi-attribute decision making in selecting the optimal via-point the robot would proceed at next step. Fuzzy decision making allows the robot to choose the most qualified via-point even when the two navigation goals-obstacle avoidance and target point reaching-conflict each other. The experimental result shows the successful navigation can be achieved with the proposed navigation algorithm for real environments.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.915-920
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• 2016

A power system designer may have difficulties in choosing a suitable multiple-input converter topology for a specific target application because each multiple-input converter topology presented in the literature has its own advantages and disadvantages. In this perspective, this paper presents a systematic topology selection method for multiple-input converters with three comparison criteria including cost-saving effect, modularity potential and flexibility. Based on these criteria, this paper proposes a strategic flow chart example for choosing a proper multiple-input converter topology. This flow chart will provide a powerful selection tool to a power system designer when he or she chooses a specific multiple-input converter for a given application.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.11-19
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• 2014

Construction VE activities has occupies an important position as a key tool of the project in terms of budget and performance improvements. Reflecting this situation, VE application scope is being expanded than before. Thus, construction projects are required the continued research and development for effective use of construction VE. VE target choice method is the central part in the construction VE work. But, this has a problem with low utilization in practical terms. Accordingly, this study was developed the new methodology(PVTCM) for VE target selection of the construction VE work. Its contents are as follows: First, to analyze practical problem for VE target choice method through VE practical data. Second, to extract the high potential VE object based on the cost model and ideas similarity by excellent VE cases analysis. Third, to implement standardized VE object item by using affinity diagram for each construction type items. This research were conducted to experts interviews for comparison analysis with the cost model as one of a representative target selection method. As a result, proposed method were implemented significantly higher performance in terms of practical effectiveness than conventional method.

• Transactions on Electrical and Electronic Materials
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• v.14 no.4
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• pp.187-192
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• 2013

Because of the importance of small target detection in infrared images, many studies have been carried out in this area. Using a Kalman filter and mean shift algorithm, this study proposes an algorithm to track multiple small moving targets even in cases of target disappearance and appearance in serial infrared images in an environment with many noises. Difference images, which highlight the background images estimated with a background estimation filter from the original images, have a relatively very bright value, which becomes a candidate target area. Multiple target tracking consists of a Kalman filter section (target position prediction) and candidate target classification section (target selection). The system removes error detection from the detection results of candidate targets in still images and associates targets in serial images. The final target detection locations were revised with the mean shift algorithm to have comparatively low tracking location errors and allow for continuous tracking with standard model updating. In the experiment with actual marine infrared serial images, the proposed system was compared with the Kalman filter method and mean shift algorithm. As a result, the proposed system recorded the lowest tracking location errors and ensured stable tracking with no tracking location diffusion.

• Ocean Systems Engineering
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• v.1 no.3
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• pp.195-205
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• 2011

A method for calibrating a laser profiling system for seafloor micro-topography measurements is described. The system consists of a digital camera and an arrangement of six red lasers that are mounted as a unit on a remotely operated vehicle (ROV). The lasers project as parallel planes onto the seafloor, creating profiles of the local topography that are interpreted from the digital camera image. The goal of the calibration was to determine the plane equations for the six lasers relative to the camera. This was accomplished in two stages. First, distortions in the digital image were corrected using an interpolation method based on a virtual pinhole camera model. Then, the laser planes were determined according to their intersections with a calibration target. The position and orientation of the target were obtained by a registration process. The selection of the target shape and size was found to be critical to a successful calibration at sea, due to the limitations in the manoeuvrability of the ROV.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1426-1447
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• 2021

The payoff game between task publishers and users in the mobile crowdsensing environment is a hot topic of research. A optimal payoff selection model based on stochastic evolutionary game is proposed. Firstly, the process of payoff optimization selection is modeled as a task publisher-user stochastic evolutionary game model. Secondly, the low-quality data is identified by the data quality evaluation algorithm, which improves the fitness of perceptual task matching target users, so that task publishers and users can obtain the optimal payoff at the current moment. Finally, by solving the stability strategy and analyzing the stability of the model, the optimal payoff strategy is obtained under different intensity of random interference and different initial state. The simulation results show that, in the aspect of data quality evaluation, compared with BP detection method and SVM detection method, the accuracy of anomaly data detection of the proposed model is improved by 8.1% and 0.5% respectively, and the accuracy of data classification is improved by 59.2% and 32.2% respectively. In the aspect of the optimal payoff strategy selection, it is verified that the proposed model can reasonably select the payoff strategy.