• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.183-188
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• 2016

Many maritime accidents have been caused by human-error including such things as inadequate watch keeping and/or mistakes in ship handling. Also, new navigational equipment has been developed using IT technology to provide various information for safe navigation. Despite these efforts, the reduction of maritime accidents has not occurred to the degree expected because, navigational equipment provides too much information, and this information is not well organized, such that users feel it to be complicated rather than helpful. In this point of view, the method of representation of navigational information is more important than the quantity of that information and research is required on the representation of information to make that information more easily understood and to allow decisions to be made correctly and promptly. In this paper, we adopt Augmented Reality (AR) technologies for the representation of information. AR is a 3D computer graphics technology that blends virtual reality and the real world. Recently, this technology has been widely applied in our daily lives because it can provide information more effectively to users. Therefore, we propose a new concept, a navigational system based on AR technology; we review experimental results from a ship-handling simulator and from an open sea test to verify the efficiency of the proposed system.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.146-153
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• 2006

A passive microfluidic delivery system using hydrophobic valving and pneumatic control was devised for microfluidic handling on a chip. The microfluidic metering, cutting, transport, and merging of two liquids on the chip were correctly performed. The error range of the accuracy of microfluid metering was below 4% on a 20 nL scale, which showed that microfluid was easily manipulated with the desired volume on a chip. For a study of the feasibility of biochemical reactions on the chip, a single enzymatic reaction, such as ${\beta}-galactosidase$ reaction, was performed. The detection limit of the substrate, i.e. fluorescein $di-{\beta}-galactopyranoside$ (FDG) of the ${\beta}-galactosidase$ (6.7 fM), was about 76 pM. Additionally, multiple biochemical reactions such as in vitro protein synthesis of enhanced green fluorescence protein (EGFP) were successfully demonstrated at the nanoliter scale, which suggests that our microfluidic chip can be applied not only to miniaturization of various biochemical reactions, but also to development of the microfluidic biochemical reaction system requiring a precise nano-scale control.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.2
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• pp.120-128
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• 2000

At the initial design stage of a new vehicle, the chassis layout has the most important influence on the overall vehicle performance. Most chassis designers have achieved the target performances by trial and error method as well as individual knowhow. Accordingly, a general procedure for determining the optimum location of suspension hard points with respect to the kinematic characteristics needs to be developed. In this paper, a method to optimize the toe angle in the double wishbone type front suspension of the four-wheel-drive vehicle is presented using the design of experiment, multibody dynamic simulation, and optimum design program. The handling performances of two full vehicle models having the initial and optimized toe angle are compared through the single lane change simulation. The sensitive design variables with respect to the kinematic characteristics are selected through the experimental design sensitivity analysis using the perturbation method. An object function is defined in terms of the toe angle among those kinematic characteristics. By the design of experiment and regression analysis, the regression model function of toe angle is obtained. The design variables which make the toe angle optimized ae extracted using the optimum design program DOT. The single lane change simulation and test of the full vehicle model are carried out to survey the handling performances of vehicle with toe angle optimized. The results of the single lane change simulation show that the optimized vehicle has the more improved understeer tendency than the initial vehicle.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.60-68
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• 2024

Purpose: When designing plants and workplaces such as handling and using chemicals, a system that can automatically determine whether the design has been made in compliance with domestic safety management laws is established to shorten the review time and increase accuracy. Method: Safety design standards for chemical handling and use workplaces were investigated, and types and systems were derived that could automatically judge design errors by dividing the articles into semantic units. Result: An automatic design review method performed when designing a building was proposed, and a system that can review the safety design requirements required when designing a chemical handling business site through the development of a rule checker was proposed. After confirming whether the law is subject to application, the safety design rules are classified into semantic units through preprocessing. The classified results can be classified into four types, and the specifications, space, conditions, situations, and specific devices and facilities to reinforce safety were analyzed as representative types. It proposes a system that prepares a diagram for the safety design rule and allows it to be reviewed through the rule checker program.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.701-708
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• 2018

Human error is an important cause of maritime accidents and the identification of human error is fundamental to maritime-accident preventions. In particular, the pattern of technical behavior taken in the circumstance of bridge teams(navigator & helmsman) provides important information to identify human error. The purpose of this study is to identify and analyze technical behavior pattern of bridge teams using Williamson's turn for rescue of persons overboard. The focus of this study is to build and analyze a cognitive model of the human behavior factors of the bridge teams in the process of implementing the experiments. The experimental environment was constructed using a ship-handling simulator and conducted an experiment on participants from 24 bridge teams. As a result of the experiment, it was able to identify the behavior pattern of the ship's maneuvering and maintain trajectory using the rudder and engine. This study is expected to correct human error in the bridge teams application to the certification and training of seafarers.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.12
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• pp.489-498
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• 2022

Recently, the textile industry, which is labor-intensive, is attempting to reduce process costs and optimize quality through artificial intelligence. However, the fiber spinning process has a high cost for data collection and lacks a systematic data collection and processing system, so the amount of accumulated data is small. In addition, data imbalance occurs by preferentially collecting only data with changes in specific variables according to the purpose of fiber spinning, and there is an error even between samples collected under the same fiber spinning conditions due to difference in the measurement environment of physical properties. If these data characteristics are not taken into account and used for AI models, problems such as overfitting and performance degradation may occur. Therefore, in this paper, we propose an outlier handling technique and data augmentation technique considering the characteristics of the spinning process data. And, by comparing it with the existing outlier handling technique and data augmentation technique, it is shown that the proposed technique is more suitable for spinning process data. In addition, by comparing the original data and the data processed with the proposed method to various models, it is shown that the performance of the tensile tenacity and elongation prediction model is improved in the models using the proposed methods compared to the models not using the proposed methods.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.1
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• pp.31-37
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• 2011

Recently gantry-type robot with 3 axes rectangular coordinates have been studied in the many industrial production equipment and machinery fields. To acquire a good handling and motion performance of this robot, reducing the settling-time and securing the accurate-transfer positioning under high-speed conditions should be required. However when robot is moved in high-speed, the large inertia of robot can lead to serious vibration of robot's head. The time-delayed control characteristics of this robot can also lead to tracking error. In this research, the analysis of the effects of higher order positional-profile is carried out to assure high-speed performance and stiffness specifications. To remove the residual vibration caused by kinematic coupling effect of dual-servo gantry, we develop a dual-servo gantry of rotary type that moving frame of x-axis rotates about z-axis. In order to decrease the tracking error, the 3 type lead-filter through system identification was applied respectively. From the experimental results, it was shown that zero-order series leader-filter has the best performance about tracking error and settling time.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.2
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• pp.68-75
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• 2018

A flare from an Air Force fighter was abnormally dispensed during the landing. To determine the cause of the abnormal dispensing, fracture analysis, signal analysis and reproduction experiments based on physics of failures were performed. The primary cause of the failure was analyzed to be due to an intermittent fault of an internal circuit card in the AN/ALE-40 chaff/flare dispenser by a broken lid of a capacitor, and the root cause which had derived the primary cause was considered to be an improper handling during the domestic maintenance which were changed from the overseas maintenance due to the DMSMS problem. Therefore, the overall process of the maintenance capability development system was reviewed and alternative ways that considers maintenance error decision aid(MEDA) for system improvement were suggested to prevent further failures.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.65-78
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• 2017

Single Event Transient has a critical impact on highly integrated logic circuits which are currently common in various commercial and consumer electronic devices. Reliability against the soft and intermittent faults will become a key metric to evaluate such complex system on chip designs. Our previous work analyzing soft errors was focused on parallelizing and optimizing error propagation procedures for individual transient faults on logic and sequential cells. In this paper, we present a new propagation technique where a fault binary decision diagram (BDD) continues to merge every new fault generated from the subsequent logic gate traversal. BDD-based transient fault analysis has been known to provide the most accurate results that consider both electrical and logical properties for the given design. However, it suffers from a limitation in storing and handling BDDs that can be increased in size and operations by the exponential order. On the other hand, the proposed method requires only a visit to each logic gate traversal and unnecessary BDDs can be removed or reduced. This results in an approximately 20-200 fold speed increase while the existing parallelized procedure is only 3-4 times faster than the baseline algorithm.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.172-176
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• 2009

We developed a program, "CogenSim-$\mu$," to simulate the operation of micro-combined heat and power (${\mu}CHP$) system. The CogenSim-$\mu$ can reflect the variation of energy efficiency by handling the real-time loads (heat and power) fluctuation. The result obtained using this program was compared with the real operation of 30 kWe gas engine driven ${\mu}CHP$. It was found that the CogenSim-$\mu$ could predict the amount of generated-power, recovered-heat and consumed-fuel with the error less than 3%, and heat and power efficiency with the error less than 4%. The CogenSim-$\mu$ reconstructed the profile of on-off cycle, which represented the operation of a facility, with more than 93% accuracy. The CogenSim-$\mu$ can reflect the effects of various factors such as size of thermal storage tank, desired temperature of reservoir water, natural frequency of generator, etc. As a result, the CogenSim-$\mu$ can be used to optimize the ${\mu}CHP$ operation.