• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.5
• /
• pp.789-798
• /
• 2020

This paper considers the development of the dynamic analysis model and simulation-based operation safety estimation of A-Frame to be applied to the test evaluation support vessel for real sea test. The support vessel will be manufactured by modifying the existing offshore support vessel. Also, development and installation of various sensors and supporting facilities for test evaluation are under preparation. Among these facilities, A-Frame is an equipment that transfers marine equipment from ship deck to the sea floor, and is being designed to transfer up to 50 ton class equipment. However, the A-Frame is a moving equipment using hydraulic cylinders. When the 50 ton equipment is attached and transferred to A-Frame, the buckling of cylinders may occur or A-Frame becomes inoperable due to the influence of huge inertia. For this reason, safety verification should be performed using dynamic analysis techniques that can take into account huge inertia forces in the design of A-Frame. Therefore, in this study, A-Frame and ship behavior were modeled using dynamic analysis method, and the applied loads of various equipment including hydraulic cylinder of A-Frame was measured and the operation safety review was performed.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2009.09a
• /
• pp.107-114
• /
• 2009

In the recent large block are used to build the ship to improve productivity. For this reason, two or more floating cranes that are connected in parallel is the trend. Typically, when working with floating crane load safety factor is considered. Even in the parallel operation, load safety factor is calculated similar to working alone. For this reason, operations do not guarantee the reliability or excessive safety factor applied. Therefore, the subdivided cases for calculating the safety factor are defined when parallel connected floating cranes are operated. Based on those cases, the operation standard is made about procedure using parallel connected floating cranes. And to verify this, dynamics simulation was performed for verification using the dynamics simulation program.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.8
• /
• pp.657-665
• /
• 2016

Launch Control System(LCS) performs the pre-launch preparation and launch operation during launch campaign. The successful launch operation is basically influenced by hardware and software of LCS. Especially, a trivial errors in control algorithm can cause critical problem or disaster in launch operation. Therefore, the hidden or implicit errors should be distinguished and eliminated by the verification test in advance. In this paper, the design and implementation of hardware and software simulator which have already been used in LCS verification will be introduced. By presenting the detailed design and flowchart-based algorithms, we make other similar systems adopt the implementation philosophies of this paper. Especially, this paper emphasizes that all the simulation algorithms work on the self-controller in LCS without using separated computer or PLC.

• Journal of Hydrogen and New Energy
• /
• v.13 no.2
• /
• pp.159-167
• /
• 2002

The operation results of the 2kW class plate type reformer, which has several advantages compared with the tubular burner type reformer, are analyzed. This plate type reformer is composed of six combustion chambers and five reforming chambers by turns. The methane conversion rate at 1.6 absolute pressure is about 84%, which is reasonably similar to theoretical value, 85.3%. Though the abrupt interruption was made just by the carbon deposition during heating the fuel line to combustion chambers around 200 hours operation, the overall steady state operation is more than 450 hours. These operation results show the verification of long run performance and the possibility of direct connection between plate reformer and fuel cell stack.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.7
• /
• pp.425-433
• /
• 2016

The construction of a light rail transit (LRT) system is a large and complex infrastructure project involving hundreds of billions of won in construction costs for a single route, and it is very important to carry out such a project from a life-cycle perspective because of its long-term operation. Systems engineering is a means and methodology to successfully implement customers' needs, and it is useful in large projects such as light rail transit. An application model called Systems Engineering for Light Rail Transit (SELRT) was developed to support systems engineering activities in light rail transit projects. In order to utilize SELRT, it is necessary to ensure that system requirements are met. As such, in this paper, we present a verification procedure and architecture based on a systems engineering-based methodology, thereby identifying the system requirements and deriving the verification requirements to confirm the SELRT model for the proposed method. The results show that the traceability of the system requirements and verification requirements, the verification method for each requirement, and the demonstration results for computerized tools are mutually connected, and that the initial requirements are clearly implemented in the SELRT. The proposed method is valid for verifying the SELRT, which can also be utilized in a LRT project.

• The Journal of Korea Robotics Society
• /
• v.4 no.2
• /
• pp.105-111
• /
• 2009

In this paper, we provide experimental results and verification for obstacle avoidance algorithm 'ELA(Emergency Level Around)', which is applicable to rescue robots. ELA is a low level intelligence-based obstacle avoidance algorithm, so can be used in fast mobile robots requiringhigh speed in operation with little computational load. Constructed system for experiments consist of laptop, sensors, peripheral devices and mobile robot platform VSTR(Variable Single-tracked Robot) to realize predetermined scenarios. Finally, experiment was conducted in indoor surroundings including miscellaneous things as well as dark environment to show fitness and robustness of ELA for rescue, and it is shown that VSTR navigates endowed area well with real-time obstacle avoidance based on ELA. Therefore, it is concluded that ELA can be a candidate algorithm to increase mobility of rescue robots in real situation.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2077-2081
• /
• 2011

Recently the train indusrty come to the fore because of Punctual, eco-friendly transportation system and becoming the main transportation. The construction plans for the trian depot for train's maintenance and storage increase constantly. For past few years, there were many construction plans, Bubal train depot, Gwangju train depot, Duckha train depot. Proper track distribution plan is important to carry out the design of railway depot for efficient maintenance operation and train storage. Through the proper design of track distribution plan, we can shorten the moving time, train movement distance, waiting time in train depot. In this paper, the verification of the track distribution plan's efficiency and appropriateness for railway depot as Bubal train depot's plan is studied and analyzed with the train depot management simulation program-Posrail(v1.0).

• Journal of the Korean Society of Safety
• /
• v.30 no.3
• /
• pp.114-122
• /
• 2015

In a fire hazard analysis (FHA) for nuclear power plant, various electrical circuit analyses are performed in the parts of fire loading analysis, fire modeling analysis, separation criteria analysis, associated circuit analysis, and multiple spurious operation analysis. Thus, electrical circuit analyses are very important areas so that reliability of the analysis results should be assured. This study is to establish essential electrical elements for each analysis for verification of the reliability of the electrical circuit analyses in the fire hazard analysis for nuclear power plants. Applying the results derived by the study to domestic nuclear power plants, it is expected to determine the adequacy of the fire hazard analysis report and contribute to the reliability of the fire hazard analysis of those plants.

• Proceedings of the KIPE Conference
• /
• 2017.11a
• /
• pp.181-182
• /
• 2017

In the battery system, an isolated converter is used for the stability of the system when controlling the charge and discharge of the battery. A fixed frequency LLC converter which is a type of isolated converter, has the advantage of high efficiency and power density with zero voltage switching at high frequency. Therefore, in this paper, the operation analysis, design and experimental verification of the LLC resonant converter with high efficiency and high power density for the ESS system were conducted.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.12 s.189
• /
• pp.80-87
• /
• 2006

Seals are usually made from elastomer, a kind of rubber, and it has the non-linearity and hyper-elasticity. U-type seals are used to prevent the leakage of internal fluid sealed in hydraulic actuator because they have more excellent performance than O-rings or rectangular seals. As a core part of hydraulic actuator, U-type seal gives much effect on performance and reliability of actuator. This study considers an NBR U-type seal under high pressure of a hydraulic actuator, and provides its deformation, stress-strain characteristic and contact force using the non-linear finite element analysis. Analysis results are compared with the experimental ones performed by the self-developed testing equipment. Verification result shows that this study presents a good application process for the effective design of U-type seals under high operation pressure.