• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2794-2797
• /
• 2008

The pneumatic waste collection system, which is a complete solution for solving the waste collection problems, are constructed in many countries all over the world. However, research data for piping network design are insufficient. In this paper the pressure losses of the straight and curved pipes, pipe junctions are obtained using the numerical method in order to investigate the optimal pipe network design for the waste collection system.

• Proceedings of the SAREK Conference
• /
• 2004.06a
• /
• pp.224-224
• /
• 2004

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.16 no.2
• /
• pp.311-317
• /
• 1998

GIS is the system that has ability of integrating, managing, and analyzing the voluminous graphic and text data, which is adequate system to manage complex network of the underground utilities of urban area. A development of pipe safety management system is accomplished to construct efficiently a database of pipe line network and topographic data, create safety managing model, and estimate openly its safety by GIS. This system is constructed to evaluate easily pipe deterioration by the establishment of the geographic output system on it, search damaged objectives near surrounding area in a situation of destruction, and offer the information by which one can take quickly emergency. And also, it is constructed to prevent from accident occurring under work by presenting underground utilities and states of work.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.5 no.3
• /
• pp.157-168
• /
• 1993

Pipe network of hot water heat supply system in an apartment house was analyzed. Flowrate and supply heat capacity of each household in which constant flowrate balancing valve is installed in a single zone system were calculated and the results were investigated. In the existing piping system, the non-uniformity of heat supply with floors due to the static pressure and temperature difference between supply main and return main can not be avoided and this tendency get intense with the increase of the height of building. The non-uniformity of heat supply can be prevented by the installation of balancing valve at each household, however if the performance of supply pump is not sufficient to overcome the energy loss due to the installation of balancing valve for constant flow rate or if the selection of the valve capacity is not adequate, the valves will may lose their controllability.

• Smart Structures and Systems
• /
• v.30 no.2
• /
• pp.173-181
• /
• 2022

The current paper presents a technique to detect crack in non-uniform cantilever-type pipe beams, that have step changes in the properties of their cross sections, restrained by a translational and rotational spring with a tip mass at the free end. An equation for estimating the natural frequencies for the non-uniform beams is derived using the boundary and continuity conditions, and an equivalent bending stiffness for cracked beam is applied to calculate the natural frequencies of the cracked beam. An experimental study for a step-changed non-uniform cantilever-type pipe beam restrained by bolts with a tip mass is carried out to verify the proposed method. The translational and rotational spring constants are updated using the neural network technique to the results of the experiment for intact case in order to establish a baseline model for the subsequent crack detection. Then, several numerical simulations for the specimen are carried out using the derived equation for estimating the natural frequencies of the cracked beam to construct a set of training patterns of a neural network. The crack locations and sizes are identified using the trained neural network for the 5 damage cases. It is found that the crack locations and sizes are reasonably well estimated from a practical point of view. And it is considered that the usefulness of the proposed method for structural health monitoring of the step-changed non-uniform cantilever-type pipe beam-like structures elastically restrained in the ground and have a tip mass at the free end could be verified.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1198-1205
• /
• 2003

Most domestic fossil power plant have exceeded 100,000 hours of operation with the severe operating condition. Among the critical components of fossil power plant, high temperature steam pipe system have had a many problems and damage from unstable displacement behavior because of frequent start up and shut down. In order to prevent the serious damage and failure of the critical pipe system in fossil power plant, 3-dimensional displacement measurement system were developed for the on-line monitoring system. 3-D Measurement system was developed with using the LVDT type sensor and rotary encoder type sensor, this system was installed and operated on the real power plant successfully. In the future time, network system of on-line diagnosis for critical pipe will be designed.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.2
• /
• pp.199-206
• /
• 2015

In this study, a new diagnosis method which can predict the working states of a pipe or its element in realtime is proposed by using an artificial neural network. The displacement data of an inspection element of a piping system are obtained by the use of PIV (particle image velocimetry), and are used for teaching a neural network. The measurement system consists of a camera, a light source and a host computer in which the artificial neural network is installed. In order to validate the constructed monitoring system, performance test was attempted for two kinds of mobile phone of which vibration modes are known. Three values of acceleration (minimum, maximum, mean) were tested for teaching the neural network. It was verified that mean values were appropriate to be used for monitoring data. The constructed diagnosis system could monitor the operation condition of a gas pipe.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.5
• /
• pp.15-21
• /
• 2008

The purpose of this study is to estimate deterioration assessment for weighting factors in pipe network for which each local selfgovernment takes rehabilitation and replacement work at present time. Deterioic hierarchy process(AHP), calculates the weighting factors. The appropriate marks matrix of sixteen deterioration factors are made for the precise decision standard of pipe condition through the result of this analysis. The marks matrix of sixteen deterioration factors can solve the complicated decision making problems of pipe rehabilitation workration factors in the pipe network might be influenced by local factors, such as province, location, or land use, in water supply systems. In this study, the sixteen deterioration factors are determined suitable for domestic situation based on the pipe deterioration factor data inside and outside of the country. Also, we select persons in charge of calculating the detail weighting factors and do survey about important level of each deterioration factors. Delphi method, a question survey method applying the analyts.

• Journal of Korean Society of Water and Wastewater
• /
• v.34 no.3
• /
• pp.221-230
• /
• 2020

In actual seawater desalination plant, the pressure loss due to frictional force of pipe is about 3~5 bar. Also, the pressure loss at pipe connection about 1~3 bar. Therefore, the total pressure loss in the pipe is expected to be about 4~8 bar, which translates into 0.111 to 0.222 kWh/㎥ of energy when converted into the Specific Energy Consumption(SEC). Reducing energy consumption is the most important factor in ensuring the economics of seawater desalination processes, but pressure loss in piping is often not considered in plant design. It is difficult to prevent pressure loss due to friction inside the pipe, but pressure loss at the pipe connection can be reduced by proper pipe design. In this study, seawater desalination plant piping analysis was performed using a commercial network program. The pressure loss and SEC for each case were calculated and compared by seawater desalination plant size.

• Korean Journal of Agricultural Science
• /
• v.47 no.3
• /
• pp.509-517
• /
• 2020

Geographic information system (GIS) sewer network data are a fundamental input material for urban inundation modeling, which is important to reduce the increasing damages from urban inundation due to climate change. However, the essential attributes of the data built by a local government are often missing because the purpose of building the data is the maintenance of the sewer system. Inconsistent simplification and supplementation of the sewer network data made by individual researchers may increase the uncertainty of flood simulations and influence the inundation analysis results. Therefore, it is necessary to develop a basic algorithm to convert the GIS-based sewage network data into input data that can be used for inundation simulations in consistent way. In this study, the format of GIS-based sewer network data for a watershed near the Sadang Station in Seoul and the Oncheon River Basin in Busan was investigated, and a missing data supplementing algorithm was developed. The missing data such as diameter, location, elevation of pipes and manholes were assumed following a consistent rule, which was developed referring to government documents, previous studies, and average data. The developed algorithm will contribute to minimizing the uncertainty of sewer network data in an urban inundation analysis by excluding the subjective judgment of individual researchers.