• Journal of Korean Society for Atmospheric Environment
• /
• v.27 no.3
• /
• pp.272-280
• /
• 2011

A novel particle removal system for air handling unit (AHU) of subway station was evaluated experimentally. The novel system was designed in order to minimize the maintenance cost by applying axial-flow cyclones. The system consists of multiple cyclone units and dust trap. Based on our previous numerical study, it was found to be effective for removal $1\sim10{\mu}m$ sized dust particles. In this study, we manufactured the mock-up model and evaluated the model experimentally. Liquid and solid test particles were generated for evaluating collection efficiency of the system and the pressure drop was monitored. The collection efficiency was varied from 41.2% to 85.9% with increasing the sizes of particle from 1 to $6.5{\mu}m$ by particle count ratio of inlet and outlet. The pressure drop was maintained constant less than $20mmH_2O$. In addition, the collection efficiency was estimated by total mass for solid test particles. It was found that the collection efficiency was 65.7% by particle mass ratio of inlet and outlet. It shows that present system can replace current pre-filters used in subway HVAC system for removing particulate matters with minimal operational cost.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.181-186
• /
• 2006

Estimation based on current data of construction performances have become one of the critical subjects which many researchers have been interested in for the past decades. In order to accomplish accurate measurement and estimation of construction performances, the method of data collection stands the highest priority. However, there are many difficulties in data collection from construction jobsite due to the characteristics of the construction industry. With developments of new technologies in other industries, several technologies has recently initiated to be applied to construction field. Electronic tags based on the identification technology, automatic volume measurement based on laser scanning technology, and Global Positioning System (GPS) have been represented the technologies which show the high opportunity for being used in construction. This study reviews specific aspects of these technologies focused on the utilization in construction jobsite. Also, the challenges which these technologies need to overcome are discussed.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.201-203
• /
• 2009

This paper presents the real time stray current monitoring techniques on the DC railway system. These techniques are two types. The first one is the rail potential measurement technique between running rail and earthing mats on the important locations such as substation, station, and so on. And the second one is measurement technique of stray current through substation earthing mats and from collection mats, and continuous monitoring of return currents through the running rails. We need to apply these techniques on DC railway system to monitor stray current periodically and maintain the system properly.

• International conference on construction engineering and project management
• /
• 2007.03a
• /
• pp.279-288
• /
• 2007

Attempts to achieve a higher productivity have led studies to focus on process improvement. Information has been found as an essential element for process improvement. This research has introduced and focused on two types of information, namely: related jobsite information along the process and feedback information. Related jobsite information along the process which needs to be processed and delivered in a timely manner, accurate, and real time is required to streamline the decision making process. Whereas feedback information about process' current practices which have to be captured and stored is a useful for continuous improvement in identifying the problem origin and determining corrective action. In the current practices, although these two types of information are essential for process improvement, construction process has faced barriers in obtaining that information. Therefore, this research will propose a new information system to overcome the aforementioned barriers. The new information system consists of RFID as an automatic identification and data collection device integrated with database to support construction processes. The new system attempts to provide related jobsite information along the process and feedback information to support decision making process and continuous process improvement respectively. A case study of prefabrication installation process in housing projects has been selected to be implemented in conceptual model of RFID application in construction industry. Conceptual model will be presented in this paper as an initial stage of this ongoing research. Expected outcomes of the new system and future works will be discussed briefly.

• Resources Recycling
• /
• v.24 no.3
• /
• pp.16-26
• /
• 2015

This study aims to suggest possible policy options for collection of post-consumer diapers as a sustainable prerequisite to implementation of public recycling system with the desktop monitoring results and analysis of collection cost involved. By conducting a diaper collection pilot test on daycare centers and households in the Seoul Nowon-gu, this study revealed that the odor issues did not stand out as an important hindering factor and that the collection rate was the largest contributing factor regarding collection costs. The exploratory cost analysis result shows that the implemented recycling system must guarantee collection rate over 50% via twice-a-week collection frequency, to be comparable or even superior to the current food waste collection cost. Also the pilot demonstration test showed that the final collection rate can be achieved as much as over 50%. The promising data thus obtained cost economically viable future diaper recycling system implementation in the entire Seoul metropolis and adjacent areas of dense population. With the concomitant development of recycling technology and related infrastructure for systematic collection of diaper waste, it makes our society much more sustainable.

• Journal of the Korean Society for Library and Information Science
• /
• v.53 no.4
• /
• pp.399-418
• /
• 2019

In accordance with the recent expansion of collection operation of independent publications through public libraries, this study conducted a status analysis on independent publications collection in public libraries and in-depth interviews with staff in charge of independent publications in order to suggest ways to effectively manage independent publications. As a result, it was deduced that the measures needed for effective management of independent publications are construction of joint cataloging system for building and sharing independent publications catalog in public libraries; platform for collecting various information of independent publications; support for ISBN, ISSN, CIP issuance of independent publications; and improvement of distribution system.

• Journal of Korean Library and Information Science Society
• /
• v.55 no.1
• /
• pp.193-214
• /
• 2024

This study aimed to propose a method for collecting and applying media platform based materials at the National Library of Korea. Firstly, we analyzed the current status and limitations of data collection based on domestic media platforms, including the National Library of Korea. Secondly, a literature review method was used to investigate the current status and types of digital content based on media platforms. Thirdly, we identified the types of materials based on media platforms that are not currently included in the National Central Library's online material collection guidelines through the examination of cases from major overseas libraries. Fourthly, after reviewing technical and legal elements such as the definition of collection targets and scope for each new media, and collection methods, we established collection criteria. Fifthly, based on the research results, the policies proposed in this study are as follows: 1) there is a need to establish a clear legal basis for the collection of media platform based materials; 2) the development and presentation of collection guidelines for media platform based materials is necessary; 3) the development of collection tools and infrastructure for media platform based materials is required; 4) for the collection of media platform based materials, it is necessary to obtain permission for collection from targeted social media organizations, and to cooperate in linkage with organizations that produce and service extended reality content; 5) for the service activation of media platform based materials, it is necessary to improve accessibility for the usage activation of these materials, to enhance the content extensibility and ease of use of the e-deposit system including extended reality content, and to advance and construct spaces for reproducing extended reality content.

• Journal of Biosystems Engineering
• /
• v.36 no.3
• /
• pp.204-210
• /
• 2011

This study developed the cyclone conveying system using roughage cutter for the round bale reported in the previous papers. Performance tests were conducted whether it can easily separate dust from roughage such as rice straws and it can transport roughages from cutter to TMR mixer. In addition, the airflow patterns in the cyclone conveying system were investigated using CFD code (FLUENT 6.2) for various velocities of dust collection fan. The cyclone conveying system was designed based on dried rice straws with a diameter of 1,340 mm, a cylinder length of 1,220 mm, a cone length of 850 mm and the current velocity of the dust collection fan was 15~20 m/s. It was found that transporting of roughage from cutter to TMR mixer and the separation of dust were satisfactory, and the dust removal rate of rice straws was around 31.9%. CFD analysis showed that, at the blowing fan velocity of 11.6 m/s, the airflow velocity inside the dust collector increased as velocity of the dust collection fan increased, but the airflow patterns inside the dust collector were all much the same.

• Journal of the Korean Society for Railway
• /
• v.17 no.3
• /
• pp.157-164
• /
• 2014

The contact force between the pantograph and the catenary is a key factor determining the current collection quality, as they can ensure stable electrical power to the train. In this study, we analyzed the dynamic contact force for HEMU-430X depending on the train speed. It was confirmed through the results that the standard deviation of the contact force increases with an increase in the train speed. It was also verified that the span of the catenary system is a very important factor with regard to the contact force when analyzed with frequency analysis. To secure stable power in speed that exceeds 400km/h, the statistical variation of the contact force should be minimized. To realize this, the catenary tension was increased and the mass of the pan-head was decreased. The ensuing effects were then quantitatively analyzed in terms of the contact force. In addition, the differences in the contact force between a tunnel and an open field were analyzed based on a frequency analysis.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.6
• /
• pp.855-859
• /
• 2014

Quality criteria for interaction between a pantograph and overhead contact wire is a most important requirement to assess of the performance for the current collection system. Interaction performance between pantograph and catenary system is subject to approval by the infrastructure manager when a new design and contraction of overhead contact line and pantograph are installed. Among the various performance, percentage of arcing at maximum line speed is a simple test method compared with contact force of pantograph due to direct sensing of pantagraph, calibrations, installations of train, and etc. On the other hand, percentage of arcing is need to reliable arcing detector and general requirements with accordance with EN 50317. In this paper, percentage of arcing are investigated on the function of duration of arc and proposed which is satiable of percentage of arcing. As a results, we proposed which duration of arcs are unsuitable from infrastructures point of view as performance testing for quality of current collection.