• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.91-102
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• 2013

This paper proposes the improved LCCT(Inductor-Capacitor-Capacitor-Trans) Z-source DC-DC converter (Improved LCCT ZSDC) which can generate the bipolar output voltages according to duty ratio D. The proposed converter has the characteristic and structure of Quasi Z-source DC-DC converter(Quasi ZSDC) and conventional LCCT Z-source DC-DC converter(LCCT ZSDC). To confirm the validity of the proposed method, PSIM simulation and a DSP based experiment were performed for each converter. In case which the input DC voltage is 70V, the bipolar output DC voltage of positive 90V and negative 50V could generate. Also, as comparison result of the capacitor voltage ripple in Z-network and the input current under the same condition for each converter, the voltage stress and the capacitor voltage in Z-network of the proposed method were lower compared with the conventional methods. Finally, the efficiency for each method was investigated according to load variation and duty ratio D.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1432-1441
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• 2012

In this study, an improved LCCT(Inductor-Capacitor-Capacitor-Trans) Z-source inverter(Improved LCCT ZSI) with characteristics of Quasi Z-source inverter(QZSI) and LCCT Z-source inverter(LCCT ZSI) is proposed. The proposed inverter can also reduce the voltage stress and input current/capacitor voltage ripples compared with conventional LCCT ZSI and Quasi ZSI. A two winding trans in Z-impedance network of the conventional LCCT ZSI is replaced by a three winding trans in the proposed inverter. To verify the validity of the proposed inverter, a DSP controlled hardware was made and PSIM simulation was executed for each method. Comparing the current and voltage ripples of each method under the condition of input DC voltage 70[V] and output AC voltage 76[Vrms], the input current and capacitor voltage ripple factors of the proposed inverter were low as 11[%] and 1.4[%] respectively. And, for generation of the same output AC voltage of each method, voltage stress of the proposed inverter was low as 175[V] under the condition of duty ratio D=0.15. As mentioned above, we could know that the proposed inverter have the characteristics of low voltage stress, low ripple factor and low operation duty ratio compared with the conventional methods. Finally, the efficiency according to load change/duty ratio and the transient state characteristics were discussed.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.562-563
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• 2012

본 연구에서는 quasi Z-소스 DC-DC 컨버터와 LCCT Z-소스 DC-DC컨버터 특성을 가지고 있으면서 커패시터에 걸리는 전압과 전압 스트레스가 개선되는 improved LCCT Z-소스 컨버터(ZSDC)를 제안하였다. 제안한 improved LCCT ZSDC의 동작원리를 설명하고, 실험을 통하여 타당성을 고찰하였다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.15-24
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• 2014

Low Cost Carrier(LCC)s in Asia Pacific market are expected to record high growth due to the expansion of Open Sky Policy among Korea, Japan, China and South East Asia. As everybody is aware of, LCC is not only saving flight cost but also creates differentiating business model by reducing unnecessary services such as F&B and in-flight duty free sales services. Booming LCCs in Asian market will cause not only Incheon airport but also other local airports in Korea to compete heavily to attract LCCs. For example, Air Asia Group with more than 200 fleet has expanded its alliance network throughout Asia. Therefore this paper has researched a new business model operating a LCC terminal for the hub airport competitiveness. According to analysis result of case study, it was found out, considering increasing airline demand next decade, Incheon airport and other domestic airports in Korea had better change an existing terminal into a LCC Terminal(LCCT) to differentiate airport services and expand its hub network. That is because of economic feasibility, first of all, of securing hub and spoke networking capabilities with airlines and finally of developing commercial facilities customizing LCC passengers' demand.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.4
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• pp.63-69
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• 2009

Incheon International Airport as the gateway to Korea is having the happiest time with those honorable prizes. But in these days, the trend of aviation is changing rapidly, so many rival airports in the world as well as north-east asian countries are rushing to find new revenue sources not to be turned over. Hence Incheon International Airport should push into fresh fields or create new sources of business keeping innovation by making foreign airports its role model. This study brings up some new profit models of foreign airports; Malaysia's Kuala Lumpur International Airport, China's Xiamen Aviation Industry Zone, German's Frankfurt Fraport Airports Group. This study analyzes the status of listed airports and presents strategies after investigating whether they are suitable for and compatible to Incheon International Airport.

• Resources Recycling
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• v.8 no.5
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• pp.28-33
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• 1999

Trus paper presenls a hydrometallurgical process Tor recovcnng ~uckcals mckcl sulfate fiom the spent nickel-cadrnlum bauery in whch c:,dmi~lm war re~novcdb y vapowing m e h d in vacuum. F ~ s ts,e lcct~vcc rushing and classification mell~odw ere performed to separate iron physically and the nickel-rich sample (over 80% nickel) was obtained. Ths sarnple was dissolved in sulf~ uiuica cid to obtain a luckcl sulfatc soluho~d~o se to its seluradon painl. TIE Cree acid in the unpurificd nickcl solut~onw as neutl-dized and iron war ve~novedk om the solulmn Thc mckel sulhte solution was c~yst~llizeadt around 45'C to obtain ruckel sulfate henahyril-ate.