• The KSFM Journal of Fluid Machinery
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• v.12 no.1
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• pp.28-34
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• 2009

The objective of this study was to draw the most suitable plan of an automatic domestic solid waste collection system for land development area. The results of this study indicated that the most suitable plan is identified as a land development area larger than 3,600,000 $m^2$ located in the metropolitan area with an incinerator system (or MBT). There are the cases smaller than the standard area but this may cause additional allotment from the residents. According to a rating method to compute the size of the most suitable plan, installation of an automatic clean network has to be minimized if the rated score is below 2.0. On the other hand, the installation is required if the rated score is above 2.5. For a certain circumstance, a cautious decision has to be made for installation of the automatic domestic solid waste collection system by considering the influence of the initial cost, sale price, residential allotment, and maintenance cost on the land development.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.727-732
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• 2017

This paper describes the dynamic characteristics depending on installation condition between a pantograph and an OCL (Overhead Contact Line) on a new high speed line in Korea. The current collection performance between the pantograph and the OCL was tested during train operation from Suseo to Jije stations. The current collection performance is evaluated based on the duration of an arc by using an arcing measurement system. The system consists of an optical sensor for measuring the duration of an arc and a camera for monitoring current collection performance. An arcing duration is defined as a percentage of arcing in international standards. This test aims to analyze the locations of repetitive arcing depending on installation conditions of OCLs on a new high speed line in order to use the result as reference data for correct construction and maintenance.

• Asian Journal of Atmospheric Environment
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• v.8 no.2
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• pp.89-95
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• 2014

There have been a lot of efforts to keep permissible emission standards and to reduce the amount of emitted air pollutants. There are several air pollution control equipments, however, wet scrubber is used to remove particulate matters and gaseous pollutants simultaneously, even if it has low collection efficiency in the particle size less than $5.0{\mu}m$. To overcome this problem, we introduced a spray tower scrubber with an electrospray system which a high voltage was indirectly applied. We found that collection efficiency of fine particles in the electrospray system was improved by increasing electrical field strength and the ratio of liquid-gas flow rate (from 41% to 84% for $0.3{\mu}m$ particles). In addition, a number of small droplets generated from an electrospray system led high collection efficiency, resulting from electrostatic attraction between droplets and particles and higher collision frequency. Therefore, we can conclude that the introduction of an electrospray system is quite effective to increase the particle removal efficiency of a spray tower scrubber.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.541-545
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• 2010

Because contemporary rolling stock system is complex and highly advanced, and it builds mutual interface, it is necessary to manage maintenance of rolling stock systematically. This study present a case, which shows how to adopt and apply RTD(Remote Transmission Device) integrated to train information collection device. After the train service is complete and the train enters the main subway station, various kinds of information collected from TCMS(Train Control Monitoring System) is transmitted to train depot information collection device through RTD. This study suggests that RTD integrated to train information collection device helps build an effective rolling stock maintenance system by improving reliability of data transmission and cutting maintenance costs.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.957-965
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• 2002

Garbage collection in the CLDC typically employs a stop-the-world GC algorithm which is performing a complete garbage collection when needed. This technique is unsuitable for the interactive Java embedded system because this can lead to long and unpredictable delays. In this paper, We present a garbage collection algorithm which reduces the average delay time and supports the interactive environment. Our garbage collector is composed of the allocator and the collector. The allocator determines the allocation position of free-list according to object size, and the collector uses an incremental mark-sweep algorithm. The garbage collector is called periodically by the thread scheduling policy and the allocator allocates the objects of marked state during collection cycle. Also, we introduce a color toggle mechanism that changes the meaning of the bit patterns at the end of the collection cycle. We compared the performance of our implementation with stop-the-world mark-sweep GC. The experimental results show that our algorithm reduces the average delay time and that it provides uniformly low response times.

• Journal of Information Science Theory and Practice
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• v.7 no.3
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• pp.52-64
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• 2019

This research was aimed at studying the situation, problems, and requirements for digital collection lifecycle management of Thai theses and dissertations. The mixed research method used was composed of: (1) Study of the problem and situation in which the qualitative method was applied. The research site covered 10 higher education institutions where the Thailand Digital Collection (TDC) project is operated. The informants were key administrative officers of the TDC project of each institution. In-depth and structured interviews were conducted on an individual basis to obtain the most accurate answers. (2) Study of requirements based on the quantitative research method to survey the requirements for the digital collection management system for Thai theses and dissertations from 84 purposively-selected TDC project officers and 527 end users selected by accidental sampling, totaling 611 samples. Research findings are as follow: (1) The study of the situation and problems of digital collection lifecycle management shows that Thai higher institutions systematically manage their digital collection. The management lifecycle is consistent with the Guidance documents for lifecycle management of ETDs, which included seven steps: program planning, creation, submission, and ingestion, access and retrieval of digital objects, archiving and preservation, evaluation and assessment, interoperation (creation of institutional collaboration), and development of link data. (2) The study of requirements for digital collection management of Thai theses and dissertations shows five system requirements: acquisition and gathering, digitization, metadata standards, management of rights, and storage and retrieval, all of which are at M (mandatory) and D (desirable) levels.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.530-537
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• 2015

The wet electrostatic precipitator (wet ESP) is an effective control device which removes submicron particles reentrained in a collection plate and water soluble gas. However, its collection efficiency decreases, as its operation is subject to water-induced distortion of the collection electrode. In order to make up for the limitation, we modified the wet ESP system by installing electrosprayed discharge electrodes. The modified wet ESP system can wash both the collection plate and discharge electrode. As a result, we were able to fabricate a compact wet ESP with a small specific collecting area ($0.18m^2(m^3/min)$) that can accomplish a high collection efficiency of fine particles (97.1%). In addition, the device obtained a relatively low specific corona power of approximately $10W/(m^3/min)$.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.13-19
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• 2018

25 local districts in Seoul have been running Waste Transfer Stations(WTSs) to secure regional collection bases, to connect between collection systems and waste treatment systems, and to commit various pre-screening of mixed wastes. There were, however, few previous researches to define how much WTSs are beneficial to waste collection system at least in Korea. So this study analyzed costs of waste collection systems with varied haul distances from waste sources(WSs) to WTS or building types of WTSs. Major results showed that the closer WTS is to WS or the cheaper the construction cost of WTS is, the lower the cost of waste collection system is. There was an additional result that WTS system with more than 15 km of total haul distance might be useful in Seoul and encapsulation of WTS in building or underground will make effective total haul distances longer up to 35km.

• The KSFM Journal of Fluid Machinery
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• v.13 no.5
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• pp.58-63
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• 2010

Optimal operation of turbo blowers connected in serial is analyzed by experimental measurements and numerical simulation with three-dimensional Navier-Stokes equations. The turbo blower system considered in the present study is widely used for the refuse collection system. Design optimization of the turbo blower using some design variables is also studied to enhance the performance of the blower. Throughout numerical simulation, it is found that the input energy reduction by optimal operation of the turbo blowers with the proper changes of the rotor's rotating frequency can be reduced a input energy for operating the blower system compared to the conventional on-off operation method theoretically. It is also found that the optimal design method is effective to enhance the performance of the turbo blower.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2461-2463
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• 2001

In this paper, we propose gateless fare collection system in the subway, which is removed the gate and it's critical to find a way to collect fares without unnecessarily delaying passengers. The gateless fare collection system consists of data communication zone and card check zone. Card's checking zone system may extract fare from two or more cards that one person carries. In this system, the multiple carrier frequencies of 125KHz and 2.45GHz are adopted.