• Journal of Energy Engineering
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• v.24 no.4
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• pp.146-158
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• 2015

A bottom-up approach has been conducted to estimate greenhouse gas (GHG) emission and to analyze the marginal abatement cost for the Korean horticulture energy sector. With the systematically derived activity and energy balance data, the BAUs have been estimated, along with the marginal abatement cost over the period 2010 through 2030. The result from the marginal abatement cost analysis may provide general guidelines and procedures for the establishment of GHG abatement polices.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.66-67
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• 2016

Modular construction is attracting attention as the solution of recent problems in construction site. Such as lack of construction workforce, increasing labor costs, work delay due to extreme weather events and strengthening government regulations. However, despite the many advantages, Modular construction has not been activated dueto high construction costs compared to other construction methods. Accordingly, the object of this study is priority derivation of prefabricated house cost reduction factors and use as basic research data. For research performance, we have analyzed the blueprint and bill of quantities of a modular construction based public dormitory which was built in 2013. In result, the proportion of modular construction and on-site construction is 66% and 34%, and the construction cost proportion by activity was devided in to construction(79%), machinery(7%), electricity(5%) and civil(9%). Among these results in order to reduce costs, interior finishing(19.4) steel-frame(16.9%), metal works(13.5%), RC(11.8%), joinery(7.3%) is the order requires focused management.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.58-68
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• 2015

A marginal abatement cost analysis has been conducted to analyze the effects of abatement measures on greenhouse gas (GHG) emissions for the Korean residential sector. A bottom-up model using MESSAGE has been developed by defining the energy demand and constructing the reference energy system for the residential sector. A great amount of activity data has also been analyzed. Abatement potentials and related costs of individual abatement measures are investigated. The result from the marginal abatement cost analysis may provide general guidelines and procedures for the establishment of GHG abatement polices.

• Journal of KIBIM
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• v.9 no.2
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• pp.1-10
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• 2019

In this research, schedule optimization is defined as balancing the number of workers while keeping the demand and needs of the project resources, creating the perfect schedule for each activity. Therefore, when one optimizes a schedule, multiple potentials of schedule changes are assessed to get an instant view of changes that avoid any over and under staffing while maximizing productivity levels for the available labor cost. Optimizing the number of workers in the scheduling process is not a simple task since it usually involves many different factors to be considered such as the development of quantity take-offs, cost estimating, scheduling, direct/indirect costs, and borrowing costs in cash flow while each factor affecting the others simultaneously. That is why the optimization process usually requires complex computational simulations/modeling. This research attempts to find an optimal selection of daily maximum workers in a project while considering the impacts of other factors at the same time through OPEN BIM based multiple computer simulations in resource leveling. This paper integrates several different processes such as quantity take-offs, cost estimating, and scheduling processes through computer aided simulations and prediction in generating/comparing different outcomes of each process. To achieve interoperability among different simulation processes, this research utilized data exchanges supported by building SMART-IFC effort in automating the data extraction and retrieval. Numerous computer simulations were run, which included necessary aspects of construction scheduling, to produce sufficient alternatives for a given project.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.22-28
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• 2013

The objectives of this study were to develop porridge with medicinal herbs and chicken breast meat and to find out the optimum mixing ratio. Several herb extracts such as Acanthopanacis senticosus, Rehmannia glutinosa, Disocorea japonica, and Poria cocos Wolf were used in the ratio of 2, 1, 1, and 1, respectively. The optimum processing condition for herbal chicken porridge was determined by a design expert program. Seventeen experimental points were selected, and herb extracts (82~101 g), chicken breast meat (30~50 g), and glutinous rice (40~60 g) were chosen as the independent variables. The measured responses were preference of taste, DPPH radical scavenging, SOD-like activity, and cost. The optimum formulation of herbal chicken porridge using the numerical analysis was set at herbal extracts (101 g), chicken breast meat (38.66 g), and glutinous rice (41.34 g) with a 0.714 desirability value. DPPH radical scavenging effect, preference of taste and the cost showed a linear model, whereas SOD-like activity showed a quadratic model indicating a higher interaction among the mixture. As a result of proximate composition of optimized herbal chicken porridge, the contents of moisture, carbohydrate, crude protein, crude lipid, and ash contents were 76.4, 9.0, 1.4, 0.5, and 1.6%, the calories of the porridge was 46.1 kcal/100 g.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.946-950
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• 2014

Bacillus licheniformis was grown in minimal nutrient medium containing 1% (w/v) of distillers dried grain with soluble (DDGS), palm kernel meal (PKM), wheat bran (WB) or copra meal (CM), and the enzyme activity of endoglucanase, ${\beta}$-glucosidase, xylanase and reducing sugars was measured to investigate a possibility of using cost-effective agricultural residues in producing cellulolytic and hemicellulolytic enzymes. The CM gave the highest endoglucanase activity of 0.68 units/mL among added substrates at 48 h. CM yielded the highest titres of 0.58 units/ml of ${\beta}$-glucosidase, compared to 0.33, 0.23, and 0.16 units/mL by PKM, WB, and DDGS, respectively, at 72 h. Xylanase production was the highest (0.34 units/mL) when CM was added. The supernatant from fermentation of CM had the highest reducing sugars than other additional substrates at all intervals (0.10, 0.12, 0.10, and 0.11 mg/mL respectively). It is concluded that Bacillus licheniformis is capable of producing multiple cellulo- and hemicellololytic enzymes for bioethanol production using cost-effective agricultural residues, especially CM, as a sole nutrient source.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.406-409
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• 2012

Recently, enormous research efforts have been focused on the development of non-precious catalysts to replace Pt for electrocatalytic oxygen reduction reaction (ORR), and to reduce the cost of proton exchange membrane fuel cells (PEMFCs). In recent years, heteroatom (N, B, and P) doped carbon nanostructures have been received enormous importance as a non-precious electrode materials for oxygen reduction. Doping of foreign atom into carbon is able to modify electronic properties of carbon materials. In this study, nitrogen and boron doped carbon nanostructures were synthesized by using a facile and cost-effective thermal annealing route and prepared nanostructures were used as a non-precious electrocatalysts for the ORR in alkaline electrolyte. The nitrogen doped carbon nanocapsules (NCNCs) exhibited higher activity than that of a commercial Pt/C catalyst, excellent stability and resistance to methanol oxidation. The boron-doped carbon nanostructure (BC) prepared at $900^{\circ}C$ showed higher ORR activity than BCs prepared lower temperature (800, $700^{\circ}C$). The heteroatom doped carbon nanomaterials could be promising candidates as a metal-free catalysts for ORR in the PEMFCs.

• Corrosion Science and Technology
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• v.21 no.5
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• pp.412-417
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• 2022

Proton exchange membrane fuel cells (PEMFCs) provide zero emission power sources for electric vehicles and portable electronic devices. Although significant progresses for the widespread application of electrochemical energy technology have been achieved, some drawbacks such as catalytic activity, durability, and high cost of catalysts still remain. Pt-based catalysts are regarded as the most efficient catalysts for sluggish kinetics of oxygen reduction reaction (ORR). However, their prohibitive cost limits the commercialization of PEMFCs. Therefore, we proposed a NiCo@Au core shell structure as Pt-free ORR electrocatalyst in PEMFCs. NiCo alloy was synthesized as core to introduce ionization tendency and autoxidation reaction. Au as a shell was synthesized to prevent oxidation of core NiCo and increase catalytic activity for ORR. Herein, we report the synthesis, characterization, electrochemical properties, and PEMFCs performance of the novel NiCo@Au core-shell as a catalyst for ORR in PEMFCs application. Based on results of this study, possible mechanism for catalytic of autoxidation core@anti-oxidation shell in PEMFCs is suggested.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.119-128
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• 2015

Domestic dominant method in subcontract cost estimate for comprehensive program management is estimation by referencing similar cases or relying on the experience and expertise of the engaged. However, this method is not reliable due to lack of accuracy, making it harder for clients to plan and budget the program. Since budget itself is roughly estimated, it becomes a source of cost rise in the course of management due to design modifications. Therefore, the client and service providers shall calculate more accurate service cost by applying objective and scientific method in order to minimize cost rise and cost related dispute. Traditional cases, in estimating program management cost, took Top-Down approach based on precedents and experience. On the contrary, this study will categorize management structure into phases and activities, issue WBS for each phase to estimated schedule and cost for each code, and take Bottom-UP approach. By taking this approach named ICEP (Integrated Cost Estimate based on Project), Set project typical model will be developed for service cost estimating, calculate cost by applying project-specific factors. Also, by analyzing progress data and allocated management cost to complement them, more efficient construction management will take shape based on program management cost standards which reflect project-specific features.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.229-232
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• 2008

A Neural network classification of human activity data is presented. The data acquisition system involves a tri-axial accelerometer in wireless sensor network environment. The wireless ad-hoc system has the advantage of small size, convenience for wearability and cost effectiveness. The system can further improve the range of user mobility with the inclusion of ad-hoc environment. The classification is based on the frequencies of the involved activities. The most significant Fast Fourier coefficients, of the acceleration of the body movement, are used for classification of the daily activities like, Rest walk and Run. A supervised learning approach is used. The work presents classification accuracy with the available fast batch training algorithms i.e. Levenberg-Marquardt and Resilient back propagation scheme is used for training and calculation of accuracy.