• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.444-449
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• 2019

The "Standard on Cargo Stowage and Securing" implemented to safely stow and secure the cargo of international shipping vessels and domestic car ferries, has also been applied to general cargo ships transported between domestic ports since J anuary 2018. As a result, a new type of cargo, such as a non-standardized steel box transported by general cargo ships to major ports in Korea from Jeju Island in Korea, must be factored as the method of safe stowage and securing according to the legal classification of cargo. This study analyzed the legal status of a steel box by analyzing the actual size, shape of steel box through field verification, collection of data from relevant agencies and finally proposed the methods of safe stowage and securing for a steel box in the cargo holds of general cargo ships. According to the relevant domestic laws and international regulations, steel boxes could be classified as pallette boxes with protective outer packing, a type of non-standardized cargo. Additionally, when a steel box is loaded into the cargo hold of general cargo ships, a method of loading and transporting them must be factored so that there is no gap in the cargo hold of ships. Verification of the safety of the tightly loading and transportation measures in the reviewed cargo hold was verified through safety of the hull structure and securing of the ship's stability. As a result of verification of the safety of the hull structure, the value of the structural strength on both sides and the floor of the cargo hold for the total weight of cargo that can be loaded in the cargo hold was satisfied, and the value of the ship's stability was satisfied with the value of GoM and the restoration of the three cross-sectional stability curve areas.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.641-648
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• 2007

Computational rotor dynamic analyses of designed composite roller for large LCD panel manufacturing process have been conducted. The present computational method is based on the general finite element method with rotating gyroscopic effects. General purpose commercial finite element code, with special rotordynamics analysis module is applied. For the purpose of numerical verification, comparison study for a benchmark dual rotor model with support bearings is also presented. Detailed finite element models for composite roller with different length are constructed and analyzed considering gravity effect in order to investigate vibration characteristics in actual operation environment. As results of the present study, rotor stability diagrams and mass unbalance responses are presented for different rotating conditions.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.69-77
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• 2011

In a large scale robot system, one of important problems is software integration, which involves three elements: modularity, reusability and stability. By these issues, the degree of convenience of system integration, its required time and the performance of the system stability can be determined. In addition, the convenience of system management can be determined by the degree of completion of service components. This paper explains the template based service component (TBSC) for the integration of service components in networked robot. The important characteristics of TBSC are automatical execution and recovery process by a PnP supporting robot framework, which helps a system operator to manage a robot system comfortably. For easy implementation and system stability, we provide a service component creator and a verification tool to developers.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.913-919
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modem version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements and improve stability. Standard CLDA (Control Law Design and Analysis) process is provided that reduce the development period of the flight control system. In addition, if this process is employed in developing flight control laws, it reduces the trial and error development and verification of control laws. This paper details the design process of developing a flight control law for the RSS aircraft, utilizing military specifications, linear and nonlinea, analysis using XMATH and ATLAS(Aircraft, Tim Linear and Simulation), handling quality tests using the HQS (Handling Quality Simulator), and real flight test results to verify aircraft dynamic flight responses.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.167.1-167
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• 2001

Although computational-fluid-dynamic methods and wind-tunnel testing can provide data about the aerodynamic characteristics of an aircraft, the determination of these and other characteristics from flight data plays and important role. The object of this study is the verification of overall aircraft system performance to improve the stability of vehicle. We have test the Velocity-173, canard-type airplane to obtain the stability data. We adopt the two identifications method, EKF and MLE, for the parameter estimation. The results are compared with those of conventional type airplane.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.961-972
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• 2008

In this paper, we consider the global exponential stability of cellular neural networks with time-varying delays. Based on the Lyapunov function method and convex optimization approach, a novel delay-dependent criterion of the system is derived in terms of LMI (linear matrix inequality). In order to solve effectively the LMI convex optimization problem, the interior point algorithm is utilized in this work. Two numerical examples are given to show the effectiveness of our results.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.379-392
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• 1996

A mathematic model was developed for the simulation of sideways overturning of agricultural tractors on slopes. The overturning motion was described as a combination of the rotational motions with respect to the first and second tipping axes using the principle of conservation of angular mementum. A stability criterion was also established in terms of angular acceleration of tractor about the second tipping axis. Verification of the proposed model was provided by comparing the stability boundaries predicted by computer simulation with those observed experimentally for an equivalent 1/6 scaled mode tractor. A good agreement was shown between the simulation and experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.84-93
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• 2004

This study carries out the performance improvement and simplification of hydraulic modulator that plays an important role in vehicle stability control systems. The mathematical models for each component of a modulator, such as pump, wheel cylinder, check and solenoid valve, accumulator, damper are derived in detail. All the mathematical models are combined to form a modulator system and implemented through a computer program, which can be controlled by a user friendly GUI. To verity the simulation, comparison between simulation and experiments has been made. After the verification of the validity of the simulation, the effects of the design parameters of the modulator on the wheel cylinder pressure is investigated. The results show that the modulator without MPA has advantage in early time pressure rise rate, and it can be simplified.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.21-30
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• 2015

PURPOSES : The purpose of this study was to evaluate the performance of rapid-setting polymer-modified asphalt mixtures with a high reclaimed asphalt pavement (RAP) content. METHODS: A literature review revealed that emulsified asphalt is actively used for cold-recycled pavement. First, two types of rapid-setting polymer-modified asphalt emulsion were prepared for application to high-RAP material with no virgin material content. The quick-setting polymer-modified asphalt mixtures using two types of rapid-setting polymer-modified asphalt emulsion were subjected to the following tests: 1) Marshall stability test, 2) water immersion stability test and 3) indirect tensile strength ratio test. RESULTS AND CONCLUSIONS : Additional re-calibration of the RAP was needed for laboratory verification because the results of analyzing RAP aggregates, which were collected from different job sites, did not deviate from the normal range. The Marshall stability of each type of binder under dry conditions was good. However, the Type B mixtures with bio-additives performed better in the water immersion stability test. Moreover, the overall results of the indirect tensile strength test of RAP mixtures with Type B emulsions exceeded 0.7. Further research, consisting of lab testing and on-site application, will be performed to verify the possibility of using RAP for minimizing the closing of roadways.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.5
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• pp.525-529
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• 2009

Most of FLC received input data from error e and change-of-error e' with no relation with system complexity. Basic scheme follows typical PD and PI or PID Controller and that has been developed through fixed ME In this paper, We studied the relationship between MF and system response and system response through changing Fuzzy variable of consequence MF and propose the simple FLC using this relationship. The response of FLC is changed according to the width of Fuzzy variable of consequence MF. As changing the Fuzzy variable of consequence MF shows various nonlinear characteristic, we studied the relation between response and MF using analytical method. We designed the effective FLC using three-variable MF and nine rules and took simulation for verification. In this study, we propose the method to design system with FLC in stability point which is an impotent characteristic of designing system. The circle criterion which is adapted to analysis the nonlinear system is put to use for proposed method. Since SISO FLC has a time-invariant and odd characteristic we can use the critical point not disk which is generally used to determine the stability in the circle criterion, to determine the stability. Using this, we can get the maximum critical point plot of SISO FLC with changing the consequence fuzzy variables. The predetermined critical point plot of FLC can be used to decide the region of the system to be stable. This method is effectively used to design the SISO FLC.