• Proceedings of the Korean Geotechical Society Conference
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• 2001.11a
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• pp.85-95
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• 2001

There has been a steady increase in closed waste landfill. Sanitary and contamination prevention systems such as liner system, leachate treatment, gas treatment system were not installed in unregulated waste landfill. This study was carried out to introduce the rehabilitation method and case of unregulated closed landfill.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.15-16
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• 2016

This paper proposes an isolated DCDC converter that consists of unregulated LLC resonant converter and non-isolated synchronous buck converter for battery charger of energy storage systems application. The unregulated converter operates as transformer with fixed duty ratio and switching frequency. The synchronous buck converter is installed in the output of the LLC resonant converter. And the converter charges and discharges the battery by controlling a current of battery. The proposed converter can get the high efficiency by separating function. This paper explains design of an unregulated converter and synchronous converter.

• Journal of ILASS-Korea
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• v.20 no.2
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• pp.121-129
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• 2015

This study was designed to investigate the emission characteristics of unregulated pollutants (Aldehyde, VOCs, PAHs) as well as regulated pollutants (CO, HC, NOx and PM) from diesel medium-duty trucks. The emission characteristics of unregulated and regulated pollutants were assessed based on regulation standards (EURO 4 and EURO 5) and intake weight (2.5 ton and 5 ton). The results show that unregulated and regulated pollutants remained almost unchanged at higher speeds but decreased at below 23.5 km/h. Reduction in unregulated and regulated pollutants was noticeable in vehicles of recent regulation standards and light intake weight. The analysis of aldehyde using UPLC showed that formaldehyde and acetaldehyde of aldehyde were most dominant. The GC/MS analysis showed that benzene, toluene, ethylbenzene and xylene of VOCs was over 80% followed by toluene, xylene, ethylbenzene and benzene. In addition, the analysis of PAHs using GC/TOF-MS indicated that bi- and tricyclic aromatic ring of aromatic compounds was 73% and 53% at 2.5 ton and 5 ton vehicles, respectively. The results of this study will be contributed to establish HAPs inventory.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.11-19
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• 2004

A software-controlled unregulated bus system in which the main bus is directly connected to a battery and the duty-ratio for PWM switch is controlled by the on-board satellite software, is usually used for LEO satellites. This paper proposes a new power-stage circuit that can be available for modularization of a power regulator which is used at the software-controlled unregulated bus system satellite. And we analyze the proposed power-stage operation according to its operating modes and verify it by performing software simulation and hardware experiment using prototype. We construct a parallel-module converter which is composed of the proposed power-stage and perform experiment to verify modular characteristics of the proposed power-stage. Finally, we verify the usefulness of the proposed power-stage by comparing above results with those of a parallel-module converter made of conventional power-stage.

• Journal of Korea Water Resources Association
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• v.49 no.7
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• pp.599-606
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• 2016

The objective of this study is to estimate the unregulated flood frequency from Chungju dam to Yangpyung gauging station for the region affected by dams based on the peak discharges simulated by storage function routing model. From the flood frequency analyses, the quantiles for the unregulated flood frequency at 6 sites have similar pattern to each other, and their averaged quantile almost matched to the result from the regional flood frequency analysis. The quantile and annual mean discharge for the unregulated flood frequency for the downstream of Chungju dam show the similar behaviour to those for the upstream area. While the quantile and the annual mean discharge for the regulated flood frequency are significantly different from those for the unregulated flood frequency. In particular, the qunatile shows severe difference as the return period increases, and the annual mean discharge has a tendency to approach to the natural flood as the distance from dam increases.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.213-217
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• 2008

The objective of this research is to investigate the leaching characteristics of unregulated heavy metals such as Ni, Zn, Ba, Be, Sb, Se, V in specified waste. 108 waste samples which were taken from the representative facilities emitting hazardous substances, were analyzed. The rate of leaching of heavy metal was measured using an official test method. From the results, wastewater treatment sludge and dust contained much Ni, and Zn was detected in all samples. Dust and waste catalyst producted from petroleum-refining process tended to reveal V in high concentration. Ba, Be, Sb, Se showed low concentration, but require additional analyses of waste generated at different industries.

• Journal of Fisheries and Marine Sciences Education
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• v.15 no.1
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• pp.81-100
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• 2003

It is undeniable that IUU Fishing are threatening so many legal fishermen' economic livelihood, negatively impact on conservation and protection of the fishery stock and ecosystem itself. Especially, negative impact of IUU Fishing resulted from the increasing fishery activities on the high seas. The Korea case of Coastal and Off-shore Fisheries, difficulties in conserving and controlling the fishery stock was brought about. Simultaneously, it is the fact that there are so many damage such as the reduction of fish Stock management program's effect, dissatisfaction of legal fishermen, over-exploiting of fish stock. Related with this kind of problem, FAO had adopted "International Plan of Action to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing(2001)". From this reason, Korea also needs to make actual efforts to prevent IUU Fishing. i.e. each nation should develop Korea action plan by Feb. 2004 and impliment it, report on implementation toward FAO. This Paper will review the definition of the IUU stipulated by "International Plan of Action on Illegal, Unreported and Unregulated Fishing" and study Korea cases of the IUU fishing. Finally, the analysis of Korea's implementation will be done, centering around the contents stated on the International Action Plan. The significance of this paper is to grope the political countermeasures against international movement of the IUU fishing prevention.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.89-95
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• 2003

In this study, we examine a large number of methods for paralleling power converter, many current control techniques and the cause and solutions of the current unbalance that occurs at the application of a paralleling scheme. For each paralleling schemes, we inspect the merits and drawbacks and analyze the characteristics of each current control methods. With previously examined and analyzed results, we develop a modularizing method that can be available for unregulated bus system. And finally, we verify the possibility of the chosen modularizing method by executing simulation and performing prototype experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.2
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• pp.145-150
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• 2006

Recently emission regulation on diesel vehicles is getting stringent and research on aftertreatment technology such as DPF and DOC has been carried out actively. Even though PM(Particulate matters) reduction efficiency in DOC is relatively low but the structure is simpler and very effective in the reduction of gas materials and unregulated materials. Therefore it has been applied to smaller diesel vehicles. The aims of this research is to investigate the emission reduction characteristics of DOC; DOC performance of regulated and unregulated material emission reduction. It results a Pt based catalyst demonstrated higher emission reduction efficiency than a Pt-V based catalyst in CVS-75 mode, and also the reduction efficiency of unidentified material was excellent.

• Journal of Power Electronics
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• v.12 no.4
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• pp.587-594
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• 2012

When a PWM rectifier has a low DC-link voltage during startup, the output voltage vector cannot be high enough to regulate the input current. This lack of a PWM rectifier output voltage vector can cause an unregulated inrush current when the rectifier operation starts. This paper presents a PWM rectifier start-up current control algorithm for when it starts operation with a lower DC-link voltage than unloaded condition case. To avoid the unregulated inrush current caused by a lack of DC-link voltage, the proposed control scheme regulates the one phase current with one switch chopping and it generates the current command considering the uncontrolled current magnitude information, which is calculated in advance. Simulation and experiment results support the validity of the proposed method.