• Ocean Systems Engineering
• /
• v.10 no.2
• /
• pp.163-179
• /
• 2020

Considering the huge demand of several types of subsea equipment, as Christmas Trees, PLEMs (Pipeline End Manifolds), PLETs (Pipeline End Terminations) and manifolds for instance, a critical phase is its installation, especially when the equipment goes down through the water, crossing the splash zone. In this phase, the equipment is subject to slamming loads, which can induce impulsive loads in the installation wires and lead to their rupture. Slamming loads assessment formulation can be found in many references, like the Recommended Practice RP-N103 from DNV-GL (2011), a useful guide to evaluate installation loads. Regarding to the slamming loads, RP-N103 adopt some simplifying assumptions, as considering small dimensions for the equipment in relation to wave length, in order to estimate the slamming coefficient C_S used in load estimation. In this article, an experimental investigation based on typical subsea structure dimensions was performed to assess the slamming coefficient evaluation, considering a more specific scenario in terms of application, and some reduction of the slamming coefficient is achieved for higher velocities, with positive impact on operability.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.311-316
• /
• 2001

A failure probability model based on Von-Mises failure criterion and the standard normal probability function is proposed. The effects of varying boundary conditions such as internal fluid pressure, external soil, traffic loads, temperature change and corrosion on failure probability of the buried pipes are systematically investigated. To allow for the uncertainties of the design variables, a reliability analysis technique has been adopted; this also allows calculation of the relative contribution of the random variables and the sensitivity of the failure probability.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.675-678
• /
• 2002

In order to develop the water hammering cleaner system for removing scale and slime in inner metal or non-metal piping wall, the flow characteristics are investigated by numerical and experimental methods. The air bubbles in the piping systems as a shock wave are formed and transferred with the water flow in the piping. The governing equations are derived from making using of three-dimensional Wavier-Stokes equations with the standard $k-{\varepsilon}$ turbulence model and SIMPLE algorithm. Pressure distributions in the pipeline are calculated for different air supply pressures. Also, we prepared some experimental results of the pressure differences for various air supply times.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.6
• /
• pp.48-55
• /
• 2004

Design for quite operation of fluid power system requires the understanding of noise and vibration characteristics of the system. This paper presents a dynamic response of design of hydraulic circuit. Experimental investigations on the attenuation of pressure ripple in automotive power steering hydraulic pipe line is examined. Also, a mathematical model of hydraulic pipe is p개posed to support a design of the hydraulic circuit. and the impedance characteristics of pressure ripple is analyzed. It is experimentally shown that power steering hydraulic pipe attenuates pressure ripple with high frequency.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10b
• /
• pp.170-175
• /
• 1992

A leak detection method for diagnosis of the leak position in a pipeline was developed using an estimation theory with the assumption that the measured flow rates and pressures are stochastic processes. A notch filter was designed using power spectral density analysis of measurements to reduce the effects of disturbances. The noise model dimension was determined by hypothesis testing and then recursive extended least square method was applied to estimate the leak position in real time. The proposed method was applied to an experimental system for evaluation of its performance.

• Journal of Welding and Joining
• /
• v.21 no.5
• /
• pp.547-554
• /
• 2003

Apparent mechanical properties in structural components can be different from the initially designed values due to the formation of the residual stress in metal forming and welding. Therefore, the evaluation of residual stress has great importance in the reliability diagnosis of structural components. A nondestructive instrumented indentation technique has been proposed to evaluate various strength concerning mechanical properties from the analysis of load-depth curve. In this study, quantitative residual stress estimation on API X65 welded joints for natural gas pipeline was performed by analyzing the variation of indentation loading curve by residual stress through a new proposed theoretical model. The residual stress from the indentation method was compared with that from the saw-cutting method.

• KIPS Transactions on Computer and Communication Systems
• /
• v.4 no.10
• /
• pp.337-342
• /
• 2015

We develop a new parallelization method for Sieve of Eratosthenes algorithm, which enhances both computation speed and energy efficiency. A pipeline scheduling is included for better load balancing after proper workload partitioning. They run on multicore CPUs with hybrid parallel programming model which uses both message passing and multithreading computation. Experimental results performed on both small scale clusters and a PC with a mobile processor show significant improvement in execution time and energy consumptions.

• Journal of Information Processing Systems
• /
• v.15 no.1
• /
• pp.189-202
• /
• 2019

During thermal power coal-fired boiler operation, it is very important to detect the pulverized coal concentration in the air pipeline for the boiler combustion stability and economic security. Because the current measurement methods used by power plants are often involved with large measurement errors and unable to monitor the pulverized coal concentration in real-time, a new method is needed. In this paper, a new method based on microwave circular waveguide is presented. High Frequency Electromagnetic Simulation (HFSS) software was used to construct a simulation model for measuring pulverized coal concentration in power plant pipeline. Theoretical analysis and simulation experiments were done to find the effective microwave emission frequency, installation angle, the type of antenna probe, antenna installation distance and other important parameters. Finally, field experiment in Jilin Thermal Power Plant proved that with selected parameters, the measuring device accurately reflected the changes in the concentration of pulverized coal.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.11 no.2
• /
• pp.141-152
• /
• 2015

Our agriculture and rural villages have faced negative conditions in many reasons. To overcome this situation, a new change is needed by the 6th industrialization. Many agriculture and rural villages in Korea are pursuing the 6th industrialization through the convergence of the primary, secondary, and tertiary industries to vitalize agriculture and rural villages. But there are several problems with the 6th industrialization. There is a limit to the capacity building of the members of the rural organization and Korean agricultural base primary, secondary, and tertiary industries are weak all. In addition, it has been insufficient research for value chain management of the region as a whole; there has been no study of information sharing across the region for the 6th industrialization. This study is about value chain management model for successful the 6th industry with Quick Response System and the big data technology. In this study to provide the efficiency of 6th industry value chain management with customer's needs analysis using big data and research for the information share between the industries in the region through the information pipeline theory of the QR System. We hope that our study is helped to proceed successfully on the 6th industrialization in Korea.

• Journal of IKEEE
• /
• v.22 no.1
• /
• pp.104-109
• /
• 2018

This paper presents a hardware design for the block encryption algorithm of ARIA which is used for standard in Korea. It presents a hardware-efficient design to increase the throughput for the ARIA algorithm using a high-speed pipeline architecture. We have used ROM for the S-box implementation. This approach aims to decrease the critical path delay of the encryption. In this paper, hardware was designed by VHDL, realized RTL level by Synplify which is synthesis tool and verified simulation by ModelSim. The ARIA algorithm is shown 68.3 MHz (Maximum operation frequency) to use Xilinx VertxE XCV Series device.