• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.2
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• pp.115-121
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• 2014

Since the rapid development of information age and information technology might be considered to cause environmental problems, Green IT is perceived as core technology for low carbon green growth and the minimum waste of electricity. In this vein, Green IT is becoming new paradigm of focusing on natural environment. This study examines current various IT required for green growth, and studies various methods for diminution of carbon discharge in Korea and other countries. Especially, it focuses on the diminution effect of carbon discharge by using Green PC, and compares the difference of voltage, voltaic current, and the use of electricity between Normal PC and Green PC by using HPM-300A, and measures carbon discharge of Normal PC and Green PC. The result shows that the diminution effect of $CO_2$ discharge of Green PC is amount to 11.5Kg per year, and the effect of green growth is up to the conservation of 2 or 3 pine trees.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.34-42
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• 2012

Green frame technology intended to facilitate the remodeling of apartment housing complexes in Korea and extend their service life has been developed. Green frame design is a Rahmen structure using composite precast concrete members and, unlike a bearing-wall structure, lifting and installing structural members accounts for major steps of structural construction. Therefore, if green frame structure construction is to be scheduled appropriately, systematic lifting plan needs to be developed in advance. Development of lifting plan also requires unit lifting process of composite PC members (columns and beams) that consist of green frame to be analyzed first. Therefore, this study attempts to analyze the lifting process of composite PC members used in green frame structure. To that end, lifting procedure and time of composite PC column and beam are estimated and applied to a project case to analyze the lifting cycle of reference floor. Outcomes produced herein will be used as key data for development of lifting plan in subsequent green frame structure construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.92-93
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• 2014

Green Frame is a method for Rahmen structure construction composed of composite PC members. The composite PC members of Green Frame which are based on in-situ production can reduce the construction cost and are more likely to secure quality when compared to production in factories. Previous studies developed forms for in-situ production of Green Frame composite PC members and proposed algorithms to arrange them on site. However, it requires not only their arrangement, but also calculation of an accurate production period to produce the required PC members in a limited space and supply them in a timely manner. In particular, it is necessary to clearly define the properties of detailed processes for in-situ production of PC members and to calculate the time required for respective process. To do so, this study is a basic research on calculating the time for in-situ production using a linear scheduling method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.176-177
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• 2013

The composite PC rahmen structure, called Green Frame, allows the main structural members such as PC column and beam to be produced on the site, resulting in a reduction of PC member transportation cost and the margin of PC plant (operation cost and profit), making it more economic than the bearing wall structure. To apply the Green Frame to practice, not only installation but also insitu-production process should be considered. Therefore, this study analyse the influence factors on insitu-production and installation schedule of composite precast concrete members. The results shall be used as basic criteria on the planning of insitu-production and installation of Green Frame.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.3
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• pp.211-219
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• 2014

This paper proposes a low voltage high current LLC resonant converter for Green PC. Green PC is composed of a lot of blade PCs, and it is a centralized system to manage them in computer center. Green PC should require that its power supplies have several characteristics such as low output voltage, high output current, and high power conversion efficiency. Conventional PSFB (Phase Shift Full Bridge) converter is usually used as DC/DC converter for computer power supply because it has high power conversion efficiency thanks to ZVS (Zero Voltage Switching) operation under middle and high load conditions. However, this converter has some problems such as large switching noise and limitation of ZVS operation under light load condition. In order to improve the performance of power supply for Green PC, a new power supply using popular high efficiency LLC resonant converter for low voltage and high current application is proposed in this paper. The proposed power supply has ZVS capability over the entire load range, thus resulting in good efficiency and high switching frequency. Experimental results verify the performance of the proposed power supply for Green PC using 2[kW] (19[V], 105[A]) rated prototype converter.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.281-286
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• 2012

In the growing standard of people's lives, we want desire to create eco-friendly water space what is called the Green Technology that is in the limelight. These green space is introduced the cultural contents and we use the water, music, and nature as tool of emotional verbalism. Presently, when we want to make scenario, water landscape scenario is made by director. but these systems have some disadvantages as the cost and limitation of direction. There is a growing interest in the integrated control system based on PC and Internet. In this paper, it is about fountain control system. Previous research area was only one using programmable logic controller or industrial PC. we proposed the development of intelligent green fountain culture system for healthy emotional self-concept. And we made automatic weather sensing system that is designed by the intelligent green fountain culture system to estimate the time-variant system.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.528-534
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• 2015

Green manure crops have been well recognized as the alternative for chemical fertilizer, especially N fertilizer, because of its positive effect on soil and the environment. Hairy vetch and green barley are the most popular crops for cultivation of rice in paddy field. This study was conducted to evaluate effects of hairy vetch and green barley on soil microbial community and chemical properties during short-term application (three years). For this study, treatments were composed of hairy vetch (Hv), green barley (Gb), hairy vetch + green barley (Hv+Gb), and chemical fertilizer without green manure crops (Con.). Hv+Gb treatment showed the highest microbial biomass among treatments. Principal component analysis (PCA) showed that PC1 (73.0 %) was affected by microbial biomass and PC2 (21.5 %) was affected by fungi, cy19:0/18:$1{\omega}7c$ (stress indicator). Combined treatment with hairy vetch and green barley could be more efficient than green manure crop treatment as well as chemical fertilizer treatment for improvement of soil microorganisms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.779-781
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• 2011

In this paper, we developed Network based Green Power Management System which is consist of EMS, Smart Plug, PC Agent and SmartPhone App. for power saving of PC and a varity of peripheral devices in office or home, and we evaluated the perfornance of our system.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.170-181
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• 1997

The number of modernized green houses have been increased to produce high quality and high-payoff farm products. The unit investment costs per pyeong($3.3058m^2$) for building a glass house was estimated at 449 thousand won. On the other hand, the unit prices for the PC house with iron frame and the vynil house with automatic control system were revealed 365 thousand won and 93 thousand won respectively. The main objective of the study was to identify the financial feasibility of the green house investment prevailed in rural area. At present, some farmers have selected the green house without any consideration of profitability of crops and accessiblity of their fanning practices and technology. For the soundness of green house cultivation and management, the indices of finacial efficiency for the modernized green houses were necessary. The decesion making criteria such as NPV(Net Present Value), IRR(Internal Rate of Return), B/C Ratio and Payback Period were analyzed for the individual high investment facilities considering the present farmer's technology and on-farm benefits and costs. The results of the feasibility analysis of green houses were as follows: 1. In case of 100% private burden of the investment costs, NPV revealed only positive value for the vinyl house with automatic system and IRR for the house was also estimated at more than 10% and B/C Ratio was amounted to more than 1.0. On the other hand, the other glass and PC houses showed negative NPV and unacceptable B/C ratio and IRR. 2. In case of the following terms and conditions as 50% Government subsidy, 20% loans and 30% farmers burden of the total investment cost, all the green houses showed acceptable IRR, B/C Ratio and NPV. 3. The financial feasibility of the glass house was acceptable in tomato cultivation rather than in cucumber cultivation. The payback periods of cucumber were represented as 8.9 years for glass house, 8.5 years for PC house and 4.1 years for vinyl house with automatic system respectively. In conclution, the glass and PC house cultivation of high value vegetables were only acceptable under the Goverment subsidy and loan systems from the view point of farmer's financial situations. On account of the unacceptable economic rate of return, the government subsidy and loan policy for glass house cultivation should be transfered to the vinyl and pc houses in the future.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2523-2528
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• 2012

Green phosphors $(Zn_{1-a-b}M_aM^{\prime}_b)_xGa_yS_{x+3y/2}:Eu^{2+}$ (M, M' = alkali earth ions) with x = 2 and y = 2-5 were prepared, starting from ZnO, MgO, $SrCO_3$, $Ga_2O_3$, $Eu_2O_3$, and S with a flux $NH_4F$ using a conventional solidstate reaction. A phosphor with the composition of $(Zn_{0.6}Sr_{0.3}Mg_{0.1})_2Ga_2S_5:Eu^{2+}$ produced the strongest luminescence at a 460-nm excitation. The observed XRD patterns indicated that the optimized phosphor consisted of two components: zinc thiogallate and zinc sulfide. The characteristic green luminescence of the $ZnS:Eu^{2+}$ component on excitation at 460 nm was attributed to the donor-acceptor ($D_{ZnGa_2S_4}-A_{ZnS}$) recombination in the hybrid boundary. The optimized green phosphor converted 17.9% of the absorbed blue light into luminescence. For the fabrication of light-emitting diode (LED), the optimized phosphor was coated with MgO using magnesium nitrate to overcome their weakness against moisture. The MgO-coated green phosphor was fabricated with a blue GaN LED, and the chromaticity index of the phosphor-cast LED (pc-LED) was investigated as a function of the wt % of the optimized phosphor. White LEDs were fabricated by pasting the optimized green (G) and the red (R) phosphors, and the commercial yellow (Y) phosphor on the blue chips. The three-band pc-WLED resulted in improved color rendering index (CRI) and corrected color temperature (CCT), compared with those of the two-band pc-WLED.