• Journal of the Economic Geographical Society of Korea
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• v.20 no.4
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• pp.486-502
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• 2017

This study investigated the formation process and networks of Korean Clean Development Mechanism(CDM) industry. It aimed to reveal the factors and the drivers for the formation processes of this industry in the specific place. Based on the analysis of the Project Design Documents(PDDs) of the CDM projects and the collected project data by international institutions, surveys, and interviews were done. On the basis of these data, the analysis on the industrial change as complex emergent effects by the network evolution caused by adaptive activity of firms is conducted. In the time of the genesis, a kind of serendipity that the industrial activities of Korean firms meet to new system, CDM, In the changing process of the Korean CDM industry, the role of policies fo Korean Government was important to promote the new and renewable energy projects of the power companies. In the time of restructuring, Korean government policies formed new initial conditions for the new domestic GHGs reduction industry. In this processes, the localization of knowledge acted as a key driver for the formation of the Korean CDM industry.

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.102-111
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• 2010

Molten carbonate fuel cell (MCFC) power plants are one of most attractive electricity generation systems for the use of biogas to generate high-efficiency ultra-clean power. However, MCFCs are considerably more expensive than comparable conventional electricity generation systems. The commercialization of MCFCs has been delayed more than expected. After being effective in the Kyoto protocol and considerably increasing the fossil price, the attention focused on $CO_2$ regression and renewable energy sources has increased dramatically. In particular, the commercialization and application of MCFC systems fed with biogas have been revived because of the characteristics of $CO_2$ collection and fuel variety of MCFCs. Better economic results of MCFC systems fed with biogas are expected because biogas is a relatively inexpensive fuel compared to liquefied natural gas (LNG). However, the pretreatment cost is added when using anaerobic digester gas (ADG), one of the biogases, as a fuel of MCFC systems because it contains high $H_2S$ and other contaminants, which are harmful sources to the MCFC stack in ADG. Thus, an accurate economic analysis and comparison between MCFCs fed with biogas and LNG are very necessary before the installation of an MCFC system fed with biogas in a plant. In this paper, the economic analysis of an MCFC fed with ADG was carried out for various conditions of electricity and fuel price and compared with the case of an MCFC fed with LNG.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.497-526
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• 2019

The importance of "decoupling" to maintain economic growth and reduce greenhouse gases is emerging as the world has been mandated to reduce greenhouse gases since the 2015 Paris Agreement. This study covered 63 countries from 1980 to 2014 and analyzed the main characteristics and causes of decoupling phenomenon between economic growth and carbon emissions. In this study, the degree of decoupling was measured every five years. The analysis found that the decoupling rate of OECD countries and countries with large incomes was high, and that the decoupling phenomenon has accelerated worldwide since the 2000s. However, the degree of decoupling was different depending on the national characteristics. According to the results of dynamic panel model, the growth rate of manufacturing and the proportion of exports hampered decoupling, while the proportion of human capital and renewable energy had a positive effect on decoupling. Also income had a inverse U-shape non-linear effect on decoupling.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1251-1264
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• 2018

The systematic and effective design method of a Class-D current-source resonant inverter for use in an induction cooker with zero-ripple line current is presented. The design procedure is based on the principle of the Class-D current-source resonant inverter with a simplified load network model that is a parallel equivalent circuit. An induction load characterization is obtained from a large-signal excitation test-bench based on parallel load network, which is the key to an accurate design for the induction cooker system. Accordingly, the proposed scheme provides a systematic, precise, and feasible solution than the existing design method based on series-parallel load network under low-signal excitation. Moreover, a zero-ripple condition of utility-line input current is naturally preserved without any extra circuit or control. Meanwhile, a differential-mode input electromagnetic interference (EMI) filter can be eliminated, high power quality in utility-line can be obtained, and a standard-recovery diode of bridge-rectifier can be employed. The step-by-step design procedure explained with design example. The devices stress and power loss analysis of induction cooker with a parallel load network under large-signal excitation are described. A 2,500-W laboratory prototype was developed for $220-V_{rms}/50-Hz$ utility-line to verify the theoretical analysis. An efficiency of the prototype is 96% at full load.

• Journal of Navigation and Port Research
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• v.35 no.6
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• pp.515-522
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• 2011

This research is intended to suggest some reference materials for the future planning of floating hotel, by reviewing the concept of floating hotel and analyzing the realized and planned ones through the search of related documents and homepages. Floating hotel can be defined as a building for living/recreation/work/entertainment with floating system on water, but without navigation tool. In terms of sequence, the River Kawi Jungle Rafts Resort was built in 1976, Four Seasons Hotel in 1988, and Salt & Sill in 2008. Floating hotels are various in scale(height) and size(room numbers), and have basic, cultural, health & marina facilities. Architectural characteristics of sample facilities can be summarized as self-supporting of the facilities, environmentally friendly architectural planning, utilization of renewable energy, introduction of new plastic composite material, and provision of same view from all bedrooms by rotating the building.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.465-469
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• 2006

Two mesophilic trickling bed bioreactors filled with two different types of media, hydrophilic- and hydrophobic-cubes, were designed and tested for hydrogen production via anaerobic fermentation of sucrose. Each reactor consisted of a column packed with polymeric cubes and inoculated with heat-treated sludge obtained from anaerobic digestion tank. A defined medium containing sucrose was fed with changing flow rate into the capped reactor, hydraulic retention time and recycle rate. Hydrogen concentrations in gas-phase were constant, averaging 40% for all conditions tested. Hydrogen production rates increased up to $10.5 L{\cdot};h^{-1}{\cdot}L^{-1}$ of reactor when influent sucrose concentrations and recycle rates were varied. Hydrophobic media provided higher value of hydrogen production rate than hydrophilic media at the same operation conditions. No methane was detected when the reactor was under a normal operation. The major fermentation by-products in the liquid effluent of the both trickling biofilters were acetate and butyrate. The reactor filled with hydrophilic media became clogged with biomass and bio gas, requiring manual cleaning of the system, while no clogging occurred in the reactor with hydrophobic media. In order to make long-term operation of the reactor filled with hydrophilic media feasible, biofilm accumulation inside the media in the reactor with hydrophilic media and biogas produced from the reactor will need to be controlled through some process such as periodical backwashing or gas-purging. These tests using trickling bed biofilter with hydrophobic media demonstrate the feasibility of the process to produce hydrogen gas in a trickle-bed type of reactor. A likely application of this reactor technology could be hydrogen gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.407-409
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• 2006

Geochemical analyses carried out on samples collected from cores on and near the southern smit of Hydrate Ridge have advanced understanding by providing a clear contrast of the two major modes of marine gas hydrate occurrence. High concentrations (15%-40% of pore space) of gas hydrate occurring at shallow depths (0-40 mbsf) on and near the southern summit are fed by gas migrating from depths of as much as 2km within the accretionary prism. This gas carries a characteristic minor component of C2-C5 thermogenic hydrocarbons that enable tracing of migration pathways and may stabilize the occurrence of some structure II gas hydrate. A structure II wet gas hydrate that is stable to greater depths and temperatures than structure I methane hydrate may account for the deeper, faint second bottom simulating reflection (BSR2) that occurs on the seaward side of the ridge. The wet gas is migrating In an ash/turbidite layer that intersects the base of gas hydrate stability on the seaward side of and directly beneath the southern summit of Hydrate Ridge. The high gas saturation (>65%) of the pore space within this layer could create a two-phase (gas + solid) system that would enable free gas to move vertically upward through the gas hydrate stability zone. Away from the summit of the ridge there is no apparent influx of the gas seeping from depth and sediments are characterized by the normal sequence of early diagenetic processes involving anaerobic oxidation of sedimentary organic matter, initially linked to the reduction of sulfate and later continued by means of carbonate reduction leading to the formation of microbial methane.

• Journal of Power Electronics
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• v.17 no.4
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• pp.892-904
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• 2017

A design of a Class-E inverter with only one inductor and one capacitor is presented. It is operated at the optimal operation mode for domestic cooker. The design principle is based on the zero-voltage derivative switching (ZVDS) of the Class-E inverter with a parallel load network, which is a parallel resonant equivalent circuit. An induction load characterization is obtained from a large-signal excitation test bench, which is the key to an accurate design of the induction cooker system. Consequently, the proposed scheme provides a more systematic, simple, accurate, and feasible solution than the conventional quasi-resonant inverter analysis based on series load network methodology. The derivative of the switch voltage is zero at the turn-on transition, and its absolute value is relatively small at the turn-off transition. Switching losses and noise are reduced. The parameters of the ZVDS Class-E inverter for the domestic induction cooker must be selected properly, and details of the design of the components of this Class-E inverter need to be addressed. A 1,200 W prototype is designed and evaluated to verify the validation of the proposed topology.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1187-1198
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• 2021

Sea wind isrecently drawing attraction as one of the sources of renewable energy. Thisstudy describes a new method to produce a 10 m resolution sea wind field using Sentinel-1 images and low-resolution NWP (Numerical Weather Prediction) data with artificial intelligence technique. The experiment for the South East coast in Korea, 2015-2020,showed a 40% decreased MAE (Mean Absolute Error) than the generic CMOD (C-band Model) function, and the CC (correlation coefficient) of our method was 0.901 and 0.826, respectively, for the U and V wind components. We created 10m resolution sea wind maps for the study area, which showed a typical trend of wind distribution and a spatially detailed wind pattern as well. The proposed method can be applied to surveying for wind power and information service for coastal disaster prevention and leisure activities.

• Journal of Korean Society of Rural Planning
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• v.25 no.3
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• pp.45-57
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• 2019

This study aims to explore the policy directions to apply and activate the appropriate technology in rural areas from the perspective of the endogenous and sustainable regional development theories. To this end, according to the analysis framework based on ideas, values, and strategies that are common to both endogenous regional development strategic theories and sustainable regional development theories, in this paper, various surveys and reviews were conducted on the study areas to explore the possibility of localization of the appropriate technology. The policy implications derived from research results are as follows; first, rural areas have high potential and scalability to apply and activate the appropriate technology, particularly in the field of renewable energy, due to their nature based on local resources. Second, for the practical application of the appropriate technology, first of all, together with the establishment of the role of public sector, it is necessary to plan the projects based on the cooperation network of the relevant innovation entities within and outside the regions and to build the implementation systems. Third, the training system for high skilled manpower and indigenous entrepreneurs should be stably built in order to create independent conditions, which are key elements for growth of the appropriate technology. Fourth, there is a need to find the market and establish policies that can solve the typical economic problems of rural areas such as aging population, depopulation and decline in youth, economic unrest. Fifth, in order for the appropriate technology to contribute to socio-economic innovations and the revitalization of the virtuous circle economy in the region, technical items and various business items suitable for the industrial infrastructures and autonomous conditions of rural areas are essential.