• 한국자동차공학회논문집
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• 제20권4호
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• pp.103-108
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• 2012

Fuel economy is an important factor in a vehicle owing to recent energy supply and environmental problems. This paper deals with fuel cell hybrid vehicles (FCHVs) and introduces a fuel economy evaluation method. The fuel economy of an FCHV depends on its power management strategy. Two rule-based power management strategies are applied to this paper and their fuel economy is evaluated based on the optimal control theory. The concept of the optimal line is also applied to this paper, which is used to compare the fuel consumption of a power management strategy to the optimal result. The two rule-based strategies are also compared to each other.

• 소성∙가공
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• 제15권8호
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• pp.609-614
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• 2006

Micro-alloyed steels(MA steels) for cold forging was developed to replace the usual quenched and tempered steel. MA steels have several advantages over the conventional quenched and tempered carbon steels. First of all, energy consumption could be lowered due to the elimination of spherodizing annealing and quenching/tempering heat treatment. Also, bending during quenching could be avoided when MA steels are applied for manufacturing of long fastener parts. However, larger amount of load is exerted on the dies compared than in the case of conventional mild steels, which might lead to the earlier fracture of dies, when MA forging steels are applied in forging practice. Therefore, die lift could be a critical factor to determine whether HA forging steels could be widely applied in cold forging practice. In the present study, authors have investigated the forging characteristics of non-heat treated micro-alloyed steel by using a series of experimental and numerical analyses. Firstly, microstructural features and its effect on the deformation behavior have been studied. Numerical analysis has been done on the forging of guide rod pin to investigate for the optimization of forging process and die stress prediction.

• 한국통신학회논문지
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• 제35권9B호
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• pp.1407-1415
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• 2010

최근 전 세계적으로 많은 관심을 받고 있는 스마트 그리드는 기존 전력망의 에너지 효율을 최적화하고자 하는 차세대 전력망을 말한다. 그 중에서 수요 반응(Demand Response)은 현재 전력망과 차별화되는 핵심 기술이다. 가정에서 전력 요금의 최소화 및 사용자의 만족도를 최대화하기 위해, 본 논문은 가정에서 사용하고 있는 여러 종류의 전력 기계의 특성을 활용하여, 최적화 문제를 통한 스케쥴링 알고리듬을 제안한다. 여러 전력 기계의 소비패턴을 수학적 모델로 유도하였으며, 하루 동안 각 시간에서 전력 기계의 중요도에 따른 최적화된 스케쥴링 기법을 제안한다. 실제 통계 수치를 활용한 본 논문의 실험 결과에서는 제안하는 최적화 스케쥴링 알고리듬이 전력요금을 최소화하는 유틸리티에 매우 효과적인 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권4호
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• pp.1276-1295
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• 2023

Sensor networks are now an essential aspect of wireless communication, especially with the introduction of new gadgets and protocols. Their ability to be deployed anywhere, especially where human presence is undesirable, makes them perfect choices for remote observation and control. Despite their vast range of applications from home to hostile territory monitoring, limited battery power remains a limiting factor in their efficacy. To analyze and transmit data, it requires intelligent use of available battery power. Several studies have established effective routing algorithms based on clustering. However, choosing optimal cluster heads and similarity measures for clustering significantly increases computing time and cost. This work proposes and implements a simple two-phase technique of route creation and maintenance to ensure route reliability by employing nature-inspired ant colony optimization followed by the fuzzy decision engine (FDE). Benchmark methods such as PSO, ACO and GWO are compared with the proposed HRCM's performance. The objective has been focused towards establishing the superiority of proposed work amongst existing optimization methods in a standalone configuration. An average of 15% improvement in energy consumption followed by 12% improvement in latency reduction is observed in proposed hybrid model over standalone optimization methods.

• KIEAE Journal
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• 제13권6호
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• pp.77-82
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• 2013

Light environment in the school building is one of the most important elements of the plan in order to improve student's ability to learn and the healthy growth. Thus, the window plan of the school building is a great addition to improve environmental-friendly performance through the daylight control. Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the school building design process, because of lack of previous studies on the light environment of student and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. ECOTECT simulation were performed using weather data. As a result, ECOTECT simulation are performed for daylight autonomy and useful daylight illuminance. Using this data, Window planing is to propose and effective method in the early stages of design.

• Journal of Community Nutrition
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• 제4권3호
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• pp.180-186
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• 2002

The food attitudes of 285 Korean female students attending a secondary school in Seoul were examined with respect to the 5 food groups of the Korean Food Tower : grain products, vegetables and fruits, meat, milk, and fats and sweets. An instrument with 22 items was utilized to measure food attitudes toward the five food groups. The items were categorized into five factors through factor analysis to obtain a description of the participants' food attitudes. The five factors are conscious choice of food, health concerns, economics and time influence, interest in foods, and foods that energize. Several facts emerged from examining the food attitudes. The most evident was their response to the items concerning the influence of economics and time on food choice, which the majority consider not limiting their food consumption. Most participants gave favorable responses for vegetables and fruits on all the five factors, but gave unfavorable responses for meat group and fats and sweets in health concerns. They also gave favorable responses for“foods that energize”for all except fats and sweets. Four of the total 25 relationships among food intake (five groups) and food attitudes (five factors) were found to have significant positive correlations (p < .01). (J Community Nutrition 4(3) : 180∼186, 2002)

• 대한전자공학회논문지SD
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• 제38권4호
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• pp.285-291
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• 2001

단열회로를 이용한 8-b×8-b 파이프라인 승산기와 4가지 위상을 가지는 전원클럭을 공급하기 위한 개선 된 구조의 전원클럭 발생기를 설계하였다. 전원클럭 신호선의 전하는 복원되어 에너지 소모를 줄인다. 단열회로는 ECRL 형태를 기본으로 하였으며 0.6㎛ CMOS 공정을 사용하여 설계하였다. 개선된 전원클럭 발생기는 기존회로보다 4∼11% 정도 효율이 높았다. 모의실험결과 제안하는 단열회로 승산기는 CMOS 승산기보다 2.6∼3.5배 정도의 에너지를 감소시켰다.

• 한국동물학회지
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• 제34권4호
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• pp.594-609
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• 1991

연안 천해에 서식하는 반부유성 갑각류인 감eomysis awatschensis를 수온 16$^{\circ}C$와 $25^{\circ}C$에서 Anemiusalina유생을 먹이로 공급하며 사육하면서 성장과 탈피에 미치는 수온의 영향을 조사, 성장, 탈피, 생식 및 호흡에 쓰인 에너지량과 체를필의 화학적 조성 및 에너지 함량을 측정한 자료로부터 개체의 사용 에너지 수지를 계산하였다. N. awatschensis 자웅의 총평균 체장성장율은 16$^{\circ}C$에서 0.08 mm/day, $25^{\circ}C$에서는 0.12maydaY였다. 수온은 동물의 각 탈피간 체장증가 백분율(growth factor)에는 영향을 미치지 않았으나 탈피기간에는 뚜렷한 영향을 나타내었다. 암컷의 체장별 각 탈피간 체장증가율은 수컷에 비하여 평균 3oye 정도 높았다. 성장과 탈피에 사용하는 평균 에너지는 각각 5.55 cal/mg X (건중, mg) 및 0.337 col/mg X (건중, mg)이였다. 난 1개의 에너지 함량은 0,057 cal이고, 암컷이 생식에 사용하는 에너지는 체장별 포란수와 관련되었다. 호흡계수는 4.5 col/ml 02였고, 회분비방법에 의한 동화효율은 70.9%였다. N. owotschensis의 총사용 에너지 중 성장에 사용하는 에너지는 갑각류의 다른 종에 비하여 높았다.

• 한국식품영양학회지
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• 제12권1호
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• pp.13-19
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• 1999

To examine the relationship between the casual infection of gastric cancer and lifestyle and nutritional status we surveyed 169 persons 90 females and 79 males aged 40∼69 years from June 7 to June 14 1997 in Whachon area Kang-Won Do Korea. For this purpose we investigated Helicobacter pylori infec-tion and identified the effect of sex age, smoking alcohol consumption economic status occupation life-style and food intake on Helicobacter phlori infection. Helicobacter pylori status was evaluated using an en-zyme-linked immunosorbant assay(ELISA) for anti-Helicobacter pylori immunoglobulin G(IgG). Helicob-acter pylori infection was present in 66.3% of total subjects namely 67.7% of female and 64.4% of male and its prevalence increased with smoking low education level and low monthly income. Energy total protein calcium and vitamin C intakes in the negative Helicobacgter phlori infection group were higher than those in positive Helicobacter pylori infection group. However iron and niacin intakes were lower in the helicobacter pylori negative group than in the positive group.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.205-212
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• 2010

The effects of chromium (Cr), dietary crude protein (CP) level, and potential interactions of these two factors were investigated in term of energy metabolism in lambs. Forty-eight 9-week-old weaned lambs (Dorper${\times}$Small-tail Han sheep, male, mean initial body weight = 22.96 kg${\pm}$2.60 kg) were used in a 2${\times}$3 factorial arrangement of supplemental Cr (0 ${\mu}g$/kg, 400 $\mu{g}$/kg or 800 ${\mu}g$/kg from chromium yeast) and protein levels (low protein: 157 g/d to 171 g/d for each animal, or high protein: 189 g/d to 209 g/d for each animal). Blood samples were collected at the beginning and end of the feeding trial. The lambs were then sacrificed and tissue samples were frozen for further analysis. Chromium at 400 ${\mu}g$/kg decreased fasting insulin level and the ratio of plasma insulin to glucagon, but these differences were not statistically significant; in contrast, chromium at 800 ${\mu}g$/kg increased the ratio significantly (p<0.05). Protein at the high level increased plasma tumor necrosis factor $\alpha$ (TNF-$\alpha$) level (p = 0.060). Liver glycogen content was increased significantly by Cr (p<0.05), which also increased liver glucose-6-phosphatase (G-6-Pase) and adipose hormone-sensitive lipase (HSL) activity. At 400 ${\mu}g$/kg, Cr increased muscle hexokinase (HK) activity. High protein significantly increased G-6-Pase activities in both the liver (p<0.05) and the kidney (p<0.05), but significantly decreased fatty acid synthase (FAS) activity in subcutaneous adipose tissue (p<0.05). For HSL activity in adipose tissue, a Cr${\times}$CP interaction (p<0.05) was observed. Overall, Cr improved energy metabolism, primarily by promoting the glycolytic rate and lipolytic processes, and these regulations were implemented mainly through the modulation by Cr of the insulin signal transduction system. High protein improved gluconeogenesis in both liver and kidney. The interaction of Cr${\times}$CP indicated that 400 $\mu{g}$/kg Cr could reduce energy consumption in situations where energy was being conserved, but could improve energy utilization when metabolic rate was increased.