• Title/Summary/Keyword: Energy consumption comparison

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Comparison of Environmental Load per Constructional Methods (Focus on Reinforced Concrete Structures and Steel-Frame Structures) (구조공법별 환경부하 산출·비교분석에 관한 연구 (철근콘크리트구조와 철골구조를 중심으로))

  • Moon, Joon-Ho;Lee, Hyun-Joo;Jung, Young-Chul;Kim, Tae-Hee;Kim, Kwang-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.193-195
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    • 2011
  • Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.

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Comparison of Energy Efficiency by Production Frontier Approach: Based on OECD Countries (생산 프론티어 접근을 통한 에너지효율 비교: OECD 국가를 중심으로)

  • Kang, Sangmok;Kim, Haechang
    • Environmental and Resource Economics Review
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    • v.20 no.1
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    • pp.33-60
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    • 2011
  • The purpose of the article is to compare the impacts of energy efficiency and economic growth for energy demand through production frontier approach in OECD countries. We compared the traditional energy intensity with energy efficiencies of production frontier approach, slack efficiency on the frontier, and estimated elasticity of energy demand for GDP growth. First, the energy intensity has a low relationship with energy efficiency by radial approach, but has constant correlations with slack energy efficiency, slack-adjusted efficiency by non-radial approach, and energy efficiency by horizon approach. If we measure energy efficiency only with energy elasticity, it may make a mistake. Especially the energy efficiency by radial approach has a tendency to overestimate most OECD countries. Second, as many countries have excess energy consumption of 17.3% even on the points of the frontier, reduction of energy consumption is necessary in addition. Third, the average energy elasticity of OECD countries is 1.1 close to elasticity 1. There exists the difference of elasticity among countries and the energy demands are also high in countries with high elasticity.

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A Study on Monthly Electric Energy Estimation of Pole-Transformer Using NLRE Curve (NLRE 곡선을 이용한 주상 변압기 월간 사용전력량 추정에 관한 연구)

  • Im, Jin-Soon;Yun, Sang-Yun;Kim, Jae-Chul
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.58-60
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    • 2000
  • In this paper we present an estimation method of electric energy[kWh] for load management of pole-transformer. For the electric energy estimation, we use the nonlinear load research based estimation(NLRE) algorithm. The NLRE curve is the normalized annual cumulative energy consumption for a particular day in a year. And, it is used for the coefficient estimation. Estimation method of suggested electric energy of pole-transformer used billing cycle electric energy estimation equation is verified as comparison billing cycle electric energy and estimated electric energy. We can reduce the error of peak load estimation by suggested method than the conventional method in domestic.

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A comparison of resident's behavior of operating air conditioner according to the charge for electric (사용자의 전기요금 부담 여부에 따른 여름철 냉방기 사용 특성의 비교)

  • Kwon, Suh-Hyun;Choi, Yoo-Rim;Chun, Chung-Yoon
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.301-305
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    • 2006
  • An electrical bill is one of the various factors that influence on energy use of residents. This study focused on electrical bills and searched that whether electrical bills affect resident behavior of operating air conditioner and their controlled indoor climate. We surveyed two groups for field study ; the one is residents who live in a studio apartment in Seoul and they are charged for electric as energy consumption they used, and the other is residents who live in a university dormitory and they are not charged for their energy consumption. We measured how long they used the air conditioner for cooling, on/off temperature of air conditioner and room temperature for these two groups. Residents were interviewed about their cooling needs, decisions about when to turn on their air conditioner and so on. We found that dormitory group has much amount of time used the air conditioner than studio apartment group and there are differences of room temperature between two groups when they turn on or off air conditioner. The result shows that perception of money affects resident behavior of operating air conditioner and their acceptable thermal range.

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Performance Comparison of MISP-based MANET Strong DAD Protocol

  • Kim, Sang-Chul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3449-3467
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    • 2015
  • A broadcast operation is the fundamental transmission technique in mobile ad-hoc networks (MANETs). Because a broadcast operation can cause a broadcast storm, only selected forwarding nodes have the right to rebroadcast a broadcast message among the one-hop and two-hop neighboring nodes of a sender. This paper proposes the maximum intersection self-pruning (MISP) algorithm to minimize broadcasting redundancy. Herein, an example is given to help describe the main concept of MISP and upper bounds of forward node have been derived based on induction. A simulation conducted demonstrated that when conventional blind flooding (BF), self-pruning (SP), an optimized link state routing (OLSR) multipoint relay (MPR) set, and dominant pruning (DP), are replaced with the MISP in executing Strong duplicate address detection (DAD), the performances in terms of the energy consumption, upper bounds of the number of forward nodes, and message complexity have been improved. In addition, to evaluate the performance in reference to the link error probability, Pe, an enhancement was achieved by computing a proposed retransmission limit, S, for error recovery based on this probability. Retransmission limit control is critical for efficient energy consumption of MANET nodes operating with limited portable energy where Strong DAD reacts differently to link errors based on the operational procedures.

Effects of Addition of Hydrogen and Water Vapor on Flame Structure and NOx Emission In $CH_4$-Air Diffusion Flame (메탄-공기 확산화염에서 수소와 수증기 첨가가 화염구조와 NOx 배출에 미치는 효과)

  • Park, Jeong;Keel, Sang-In;Yun, Jin-Han
    • Journal of Hydrogen and New Energy
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    • v.18 no.2
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    • pp.171-181
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    • 2007
  • Blending effects of hydrogen and water vapor on flame structure and NOx emission behavior are numerically studied with detailed chemistry in methane-air counterflow diffusion flames. The composition of fuel is systematically changed from pure methane and pure hydrogen to the blending fuels of methane-hydrogen-water vapor through the molar addition of $H_2O$. Flame structure is changed considerably for hydrogen-blending methane flames and hydrogen-blending methane flames diluted with water vapor in comparison to pure methane flame. These complicated changes of flame structures also affect NOx emission behavior considerably. The changes of thermal NO and Fenimore NO are analyzed for various combinations of the fuel composition. Importantly contributing reaction steps to thermal NO and Fenimore NO are addressed in pure methane, hydrogen-blending methane flames, and hydrogen-blending methane flames diluted with water vapor.

Average Dietary Energy Intake does not Increase as BMI Increased in the National Health and Nutrition Examination Survey Data of Korea

  • Ahn, Younjhin;Paik, Hee-Young;Lee, Hong-Kyu
    • International Journal of Human Ecology
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    • v.4 no.2
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    • pp.27-37
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    • 2003
  • Although the idea that obese people consume higher calorie diets is widely accepted, many dietary surveys have shown that obese people do NOT consume larger amounts of energy. We had an opportunity to study the relationship between calorie intake and obesity in Korea from the data contained in the '98 National Health and Nutrition Examination Survey of Korea. The survey was executed nationwide for two months - from Nov. 1 to Dec.30 in 1998. The survey included 10,876 (aged >10 years) subjects of whom 9,771 underwent health examinations. Surveyors visited each household and checked health status, measured anthropometry and blood pressures, collected blood and urine samples, and interviewed from the health questionnaires. Well-trained dietitians evaluated the food consumption of 11,525 subjects over the age of 1 year with the 24-hour recall method. The number of subjects from whom a complete health examination and food consumption information was obtained was 8,004. Subjects were classified by BMI (< 20, 20-22, 22-24, 24-26, 26-28, 28 $\leq$) and into newly diagnosed patients with DM (FBS $\geq$ 126 mg/㎗), hypertension (SBP $\geq$ 140 mmHg or DBP $\geq$ 90 mmHg) and hyperlipidemia (Total cholesterol $\geq$ 220 mg/㎗ or TG $\geq$ 200 mg/㎗). Our main results were as following:1) their average energy intake was 2,029.6 $\pm$ 908.5 ㎉ and BMI is 22.6 $\pm$ 3.4 kg/$m^2$;2) a comparison of nutrient intakes by BMI level did not show a significant difference of energy intake even though BMI increased (BMI, < 20: 1,999 ㎉ ∼ 28 $\leq$: 2,028 ㎉);and 3) Even in newly diagnosed patients with diabetes, hypertension or hyperlipidemia, their energy consumption was not significantly increased as BMI increased (from BMI 20). There are several possible explanations for these results:1) Reduced physical activity caused the weight of obese people to increase even with the same energy intake;2) people underreported their energy consumption;or, people intentionally reduced their energy consumption due to self-image regarding their obesity. We might also hypothesize that there is a metabolic problem conceiving obese people, because calorie intake was not higher in obese people than in non-obese people in Korea. Further research is necessary for re-evaluating these current conclusions.

Comparison of Nutrient Intakes of Elderly Korean and American Women Using Diet Quality Index

  • Chung, Chin-Eun;Sungsoo Cho
    • Nutritional Sciences
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    • v.2 no.2
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    • pp.107-112
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    • 1999
  • Diet quality index DQI) offers a new way of comparing eating habits across populations and across countries. Nutrients and food consumption data from 100 elderly Korean women aged 65 and older were collected in Seoul or Kyunggi-do, Korea by the 24 hour recall method. Diet quality index (DQI) was computed for 1049 elderly women (65 and older) from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) in the US according to US dietary guidelines, and applied to the diet of elderly Korean women for purposes of comparison. A modified 16-point DQI awarded 2 points each for moderate consumption of fat ($\leq$ 30% energy), saturated fat ($\leq$ 10%), cholesterol ($\leq$ 300 mg/day), sodium ($\leq$ 2400 mg/day), and protein ($\leq$ 100% RDA), adequate intakes of carbohydrate ($\qeq$50% energy) and calcium ($\qeq$ 100% RDA), and plenty of fruits and vegetables ($\qeq$ 5 servings). Criteria were based on US dietary guidelines. Partial scores were given if subjects were close to meeting these cutoff points. Diets with $\leq$ 300 mg cholesterol/day were reported by 97% or the Korean sample and 82% of the American sample, while 90% of the Koreans and 42% of the Americans met the goal of $\leq$ 30% of energy from fat, and 98% of the Koreans and 47% of American met the recommendation of $\leq$ 10% of energy from saturated fat. In contrast, only 8% of the Korean sample met the sodium recommendation of $\leq$ 2400 mg sodium per day, whereas 54% of the American subjects met this goal. The mean DQI scores were 10.1 for the elderly American women and 11.3 for the elderly Korean women. Overall, the elderly Korean diet was more consistent with the US dietary guidelines than the elderly American diet.

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Research on using the exhausted heat from subway tunnel as unused energy (미활용 에너지원으로서의 지하철 배열이용에 관한 연구)

  • 김종렬;금종수;최광환;윤정인;박준택;김동규;김보철;정용현
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.695-701
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    • 1998
  • Researches on unused energy are being continued because of the limited fossil fuel and the destruction of environment. Therefore this study was peformed as follows. The collectable amount of exhausted heat for an air-conditioning was calculated by the subway thermal environment prediction program. And the electric power needed by conventional heat source equipments was compared with one by unused heat source equipments when the exhausted heat was used by heat pump in heating and hot water supplying. The results are summarized as follows; 1) Forced ventilation should be conducted to keep optimal temperature in subway tunnel in summer as well as in winter. According to the simulation, temperature in tunnel was higher than that on the ground in summer when the forced ventilation was conducted only in winter. 2) Ventilating time should be calculated out to the optimal condition for not only saving power of ventilation fan but reusing exhausted heat. By the simulation, it is certain that the exhausted heat should be eliminated in air-conditioning time. 3) The use of exhausted heat source heat pump could save 8% of electric power per hour in comparison with existing heat pump. It was based on a present heat generation and traffic for ventilating time of general air-conditioning, but could be different by ventilating time. 4) As the traffic increases up to 1.5 or 2 times, electric power consumption of the conventional heat pump increases to 11% or 13.5% per mean hour in comparison with that of the exhausted heat source heat pump, though all-day ventilation.

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Effect of Air Conditioning System on Vehicle Fuel Economy in a Passenger Car (Air Conditioning System이 차량 모드 주행 연비에 미치는 영향 연구)

  • Kim, Dae-Kwang;Cho, Geun-Jin;Park, Jin-Il;Lee, Jong-Hwa
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.1
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    • pp.16-22
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    • 2007
  • Fuel efficiency is one of the major issues in regard to energy and environment. As customers desire more comfortable vehicles, increase of accessory traction force is necessary. Air conditioning system (ACS) consumes the biggest traction force among accessories, especially during summer. This means ACS is the primary object deteriorating fuel economy among accessories. Since direct measurement of traction force and fuel consumption in practical vehicle is difficult, comparison analysis is taken between vehicle with and without ACS working. For this comparison, real time measurements are carried out to know ACS traction force and fuel consumption. As a result of the comparison, a vehicle without ACS operation was 15.92% superior to a vehicle with ACS operating. It could be used as a fundamental material for improvement ACS for better fuel efficiency.