• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1256-1261
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• 2015

Along with the increase of railway catenary system operation speed to 400 km/h, there have been growing demands for good quality current collection systems that satisfy quality standards as well as criteria for safe working. Retaining uniform elasticity tension of contact wires is essential in maintaining high quality contact between pantograph and OCL (Overhead Contact Line) of current collection systems in high speed railways. Therefore, the tension of contact wire must be kept within tight tolerance limits in both working conditions and adverse weather conditions of catenary system. In accordance with these conditions, this paper presents a real time monitoring system for the tensioning device of the newly installed catenary system on the special route of Honam high speed line for 400 km/h operation. For the verification of the true value of tension of contact wires, we have developed ring-type tensioning sensors which were installed on supporting points of mast which compose the catenary system. According to the field test performed on the Honam high speed line catenary system, variation of tension was measured accurately in real-time.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.4
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• pp.153-161
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• 2021

Real-time access is required to handle continuous and unstructured data and should be flexible in management under dynamic state. Platform can be built to allow data collection, storage, and processing from local-server or multi-server. Although the former centralize method is easy to control, it creates an overload problem because it proceeds all the processing in one unit, and the latter distributed method performs parallel processing, so it is fast to respond and can easily scale system capacity, but the design is complex. This paper provides data collection and processing on one platform to derive significant insights from various data held by an enterprise or agency in the latter manner, which is intuitively available on dashboards and utilizes Spark to improve distributed processing performance. All service utilize dockers to distribute and management. The data used in this study was 100% collected from Kafka, showing that when the file size is 4.4 gigabytes, the data processing speed in spark cluster mode is 2 minute 15 seconds, about 3 minutes 19 seconds faster than the local mode.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.124-129
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• 2021

As the 4th industrial era is in full swing, the public's interest in related technologies such as artificial intelligence, big data, and block chain is increasing. As artificial intelligence technology is used in various industrial fields, the need for research methods incorporating artificial intelligence technology in related fields is also increasing. Evidence collection among digital forensic investigation techniques is a very important procedure in the investigation process that needs to prove a specific person's suspicions. However, there may be cases in which evidence is damaged due to intentional damage to evidence or other physical reasons, and there is a limit to the collection of evidence in this situation. Therefore, this paper we intends to propose an artificial intelligence-based evidence collection system that analyzes numerous image files reported by citizens in real time to visually check the location, user information, and shooting time of the image files. When this system is applied, it is expected that the evidence expected data collected in real time can be actually used as evidence, and it is also expected that the risk area analysis will be possible through big data analysis.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.495-503
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• 2019

This study explored the method of determining the appropriate size of the workforce according to the assessment of the workload of medical technologists (also called medical and clinical laboratory technologists, and medical and clinical laboratory scientists) in order to present a standard production model for the appropriate manpower in blood collection rooms. The eleven university hospitals selected for this study had between 600 and 2,000 beds. The 14-steps standard blood collection time was 4 minutes and 8 seconds for the outpatients aged between 20 to 60 years old (57%) except for children and the elderly (43%). Assuming that there were 8 hours per day for mechanically collecting blood, the maximum number of blood donations by one clinical laboratory scientist was analyzed to be 100 cases. In conclusion, it is appropriate to have fewer than 100 cases of daily blood collection by a medical technologist engaged in blood collection. Since the proper number of blood collection workers (100% of blood collection work)=the number of annual working days/(one day's work hours/time per case)×the number of working days per year, then the proper number of blood collection workers (one day's work hours)=the number of working days per year/100×the number of working days).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.6
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• pp.702-713
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• 1998

The characteristics of flow and particle collection for an electrocyclone with a central wire inside a high efficiency Stairmand cyclone was numerically analysed. Turbulent flow field was modeled by the Reynolds stress model and solved with an FVM code FLUENT. Particle motion and in-situ charging were simultaneously solved by a Lagrangian integration with time. The flow field obtained was in good agreement with experiments in the outer region. The characteristics of collection enhancement due to electric force were well manifested and well explained based on first principles. The effect of the in-situ charging process was very similar to the case of a simplified assumption of saturated charging, and the effect of the hopper was proved negligible.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.103-108
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• 2010

This article presents computational fluid dynamics (CFD) simulations of nanoparticle movements and flow characteristics in laboratory-scale electrostatic precipitator (ESP) without corona discharge, and for simulation, it uses the commercial CFD program(CFD-ACE) including electrostatic theory and Lagrangian-based equation for nanoparticle movement. For validation of CFD results, a simple cylindrical type of ESP is simulated and numerical prediction shows fairly good agreement with the analytical solution. In particular, the present study investigates the effect of particle diameter, inlet flow rate, and applied electric potential on particle collection efficiency and compares the numerical prediction with the experimental data, showing good agreement. It is found that the particle collection efficiency decreases with increasing inlet flow rate because the particle detention time becomes shorter, whereas it decreases with the increase in nanoparticle diameter and with the decrease of applied electric voltage resulting from smaller terminal electrostatic velocity.

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.343-348
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• 2003

We have investigated in detail the operating properties of Gas Electron Multiplier (GEM) detectors with a double conical and a cylindrical structure in a wide range of external fields and GEM voltages. With the double conical GEM, the gain gradually increased with time by 10%; whereas this surface charging was eliminated with the cylindrical GEM. Effective gains above 1000 were easily observed over a wide range of collection field strengths in a gas mixture of $Ar/CO_2(70/30)$. The transparency and electron collection efficiency were found to depend on the ratio of external field and the applied GEM voltage; the mutual influence of both drift and collection fields was found to be trivial.

• Journal of Korean Library and Information Science Society
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• v.34 no.1
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• pp.173-193
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• 2003

The purpose of this study is to expand understanding among librarians of the importance of caricatures, cartoons and comics in the library collection. To do so, the writer explores the characteristics, meaning, artistic value, and benefits of this realm. The writer also examines traditional as well as changing attitudes of the public toward caricatures cartoons and comics. As this study progresses. it will prove that caricatures. cartoons and comics are very important cultural products of our time, to which all libraries should pay more attention. Thus the writer urges that the library should make a good collection in this are and make it available to the public.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.739-748
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• 2004

A hybrid dust-collector combining a fabric filter with centrifugal force was developed to enhance the performance of the conventional fabric filter systems and its performances were evaluated to compare to that of the existing dust collector. The pressure drop rapidly increased with increasing the elapsed time and the face velocity in two filtration systems. But the increasing ratio of a hybrid dust-collector compare to the existing dust collector was lower. This results were confirmed from the performance such as cleaning interval, residual pressure drop and dust loading rate. The overall collection efficiency of the hybrid dust-collector was more than 99.6% and this showed a improvement of 0.6～2% than that of the existing dust collector. Especially, the fractional collection efficiency at the particle size of around 1${\mu}{\textrm}{m}$ is about 4% higher than that of the existing dust collector.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.771-775
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• 2011

This paper presents design process of linear induction motor in dynamic tester for catenary-current collection. To minimize length of rail for dynamic tester for catenary-current collection, accelerating performance of the linear induction motor is very important. So the design process of linear induction motor considered in this paper is different with general design process of linear induction motor, because dynamic tester has three type driving region, as accelerating region, constant speed region, and braking region. Considering accelerating performance of motor, distance and time from starting point to constant speed region were concerned for load condition of motor. Designed linear induction motor was analyzed by 2-dimensional finite element method. Using mechanical dynamics simulation with analysis result of 2-dimensional finite element method and accelerating performance of designed motor was proved.