• Journal of Biosystems Engineering
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• v.16 no.2
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• pp.167-177
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• 1991

곡물 빈에서 벼 건조시 외기 온도에 따른 연료 자동 조절 및 배출공기의 재순환이 에너지 소비, 건조비용 및 건조 시간에 미치는 효과를 분석하기 위해 슬램 II(SLAM II : Simulation Language for Alternative Modeing II)를 이용한 시뮬레이션 모텔을 개발하였다. 따라서 약 64톤의 벼를 연료 자동조절 버너를 갖춘 곡물빈에서 열풍 건조할 때, 절약 가능한 에너지 양과 공기 재순환의 효과를 시뮬레이션을 통해 분석하였으며 이를 실제의 자료와 비교하여 이 모델을 검증하였다. 시뮬레이션에 의한 본 연구의 결과는 다음과 같다. 1. 배출공기를 재순환 시키지 않는 상태에서 자동 연료조절 버너를 사용할 경우 관행 버너를 이용한 빈 시스템에 비해, 루이지애나 주에서 8월에 25%의 에너지를 절약할 수 있으며 12월에는 8%의 에너지를 절약할 수 있다. 실제의 건조 실험에서는 8월에 약 30%의 에너지를 절감할 수 있었다. 2. 자동 연료조절 버너를 갖춘 빈 시스템에서 제습을 하지 않은 배출 공기의 재순환은 건조 에너지 소비량과 건조 시간을 증가시켰으며 연료 자동조절 장치의 에너지 절약 효과를 감소시켰다. 따라서 배출 공기를 재순환하여 에너지를 절감하고자 할 때에는 반드시 배출 공기를 제습시켜 습도를 재조절 해야만 했다. 또한 제습된 공기의 재순환 효과는 여름보다 겨울에 더 컸다. 3. 연료 자동조절 버너를 갖춘 빈 시스템에서 벼를 건조할 경우 루이지애나 주, 8월에 물벼의 톤당 건조 비용은 $2.13이었으며 관행 버너를 갖춘 시스템에서는 $2.69이었다. 실험에 의한 실제 건조비용은 자동화 시스템에서 $2.17이었고 관행 시스템에서는 $2.62이었다.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.159-198
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• 2010

The Korean government is planning to introduce the Renewable Portfolio Standard (RPS) system to replace the currently used Feed-in-Tariff (FIT) system which is a subsidy-based mechanism to foster the renewable energy industry. The RPS system is a market-oriented system in which the power companies are obliged to use renewable energy sources to produce electricity by a certain ratio of their production level. They can either produce for themselves or simply purchase the REC (renewable energy certificate) in the market to implement. The objective of this article is to compare the RPS system with the current FIT system in terms of the implementing cost to achieve the policy goal to expand the share of renewable energy m the total power generation. The analysis is conducted using Linear Programming models. The results of this study imply several policy suggestions to successfully introduce the RPS system.

• Korean Journal of Construction Engineering and Management
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• v.1 no.1 s.1
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• pp.80-86
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• 2000

The future costs of energy and the cost of the repair of apartment buildings are expected to rise continuously in proportion to the initial costs. Therefore it has become important for these increasing costs to be incorporated and reflected in the design of the building. Systems such as structure and services for the buildings remain constant, but a number of the walls and windows can vary and thus have a major influence on the total construction and running costs of a building. The critical factor in the apartment unit design for the optimization of life cycle cost (LCC) is the ratio of the x and y axis of the walls in the unit plan. This paper demonstrates how to achieve the optimal size and thus optimize the LCC of the building.

• Journal of Energy Engineering
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• v.6 no.2
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• pp.188-197
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• 1997

MARKAL model was applied for assessment of iron and steel technology for the year of 2032 considering cost and environmental effects based on 1992. Technology, energy and material flows were analyzed in iron and steel sector. Reference iron and steel system was designed according to this analysis. Six scenarios were developed considering cost and environmental limitations such as CO$_2$emission control and SOx reduction cost. Competitiveness of technologies in iron and steel sector was assessed under different environmental limitations with cost minimization. Through this study, it was confirmed that MARKAL model can be applied to technology assessment in the field of iron and steel industry.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.505-510
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• 2009

Sensor networks are composed of a great number of sensor nodes. Since all sensor nodes are energy-restricted and hard to recharge, it is very important.However, the energy consumption may significantly increase if mobile sources or sinks exist in sensor networks. The reason is that the routing information for mobile sources and sinks needs to be update frequently for efficientdata delivery. The routing algorithm supporting mobile sinks should consider not only continuous data delivery but also the energy consumption of sensor nodes. However, most of the existing research focuses on even energy consumption while the mobility of sinks and sources is rarely consider. In this paper, we propose an efficient routing protocol with multiple virtual grids to reduce energy consumption and improve packets delivery efficiency. Then this paper considers the mobility. Simulation results show that our algorithm can guarantee high data delivery ratio and lower average delivery delay, while consuming lower energy than existing routing protocols in sensor networks.

• The Magazine for Energy Service Companies
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• s.25
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• pp.40-51
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• 2003

• Journal of the Korean Solar Energy Society
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• v.24 no.3
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• pp.93-100
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• 2004

This study aims to presents the applicability of economic measures for renewable energy The basic principle and method of economic analyses were investigated and total life cycle cost considering environmental costs according to $CO_2$ generation. In case study, adaptation of new small wind power system to buildings were proved to produce a profit if it is considered the environmental cost and increment of energy prices. And so the economic measures can be used not only for the investment decisions for economic analysis but also for the comparative analysis of environmental cost and economic profits.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.799-805
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• 2009

To construct the production system of forest biomass as a small scale heating energy source, energy availability of wood-chip was examined by cost and energy balance analysis in the production process. The costs to produce wood-chip of 1 kg was calculated by yarding machines and their operational gradient conditions. As a result, 195.45~210.54 won/kg were required as production costs of wood-chip. Input energy rate (%) which is output to input energy in wood-chip production process were showed as 26.58~27.38%. Energy input rate by operational gradient was not significantly difference, and scenario B with tower yarder system appeared by more efficient than scenario A with tractor yarding system in opposition to production costs analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.574-580
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• 2019

Conventional energy efficient routing protocols apply high weight to energy among routing metrics, causing nodes to concentrate on energy efficient paths and quickly exhaust energy on those paths. The unbalanced energy consumption of these wireless sensor networks causes network division and malfunction, and reduces network lifetime. Therefore, in this paper, it proposes a link cost based routing protocol to solve the unbalanced energy consumption of wireless sensor networks. The proposed routing protocol calculates the link cost by applying the weight of the routing metric differently according to the network problem situation and selects the path with the lowest value. As a result of the performance analysis, it confirmed that the proposed routing protocol has 22% longer network life, 2% energy consumption standard deviation and 2% higher data reception rate than the existing AODV protocol.

• The Magazine for Energy Service Companies
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• s.40
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• pp.16-19
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• 2006

국내 유일의 이산화티타늄(TiO₂) 생산업체인 코스모화학(주)이 울산 온산사업장에 최근 농축시스템 TVR을 도입, 연간 14억원의 스팀비용을 절감할 것으로 보인다. 고유가와 저가 중국산 공세에 대응하기 위한 에너지비용 절감차원에서 도입한 TVR시스템은 스팀 사용량의 50%를 절감하고도 품질수준을 한 단계 업그레이드 한 것으로 평가받고 있다.