• 한국정보전자통신기술학회논문지
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• 제13권6호
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• pp.568-574
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• 2020

본 논문에서는 영상처리에 사용되는 Canny edge 검출 알고리즘 중 가장 높은 연산 복잡도를 가진 제곱근 연산 횟수를 감소시키는 방법을 제안한다. 제안하는 방법은 기울기 벡터 연산 과정에 사용되는 제곱근 연산을 이용할 때 일부 픽셀에 특정한 규칙을 사용해 홀을 만들어 제곱근 연산을 직접 하지 않고 주변 픽셀들의 연속성을 이용하여 기울기 벡터를 계산하여 연산 횟수를 감소시킨다. 다양한 테스트 이미지를 이용해 실험한 결과 홀이 1개인 경우 약 97%, 홀을 증가시키면 각각 약 94%, 90%, 88%의 일치율을 보였고, 홀이 1개인 경우에는 0.2ms의 연산시간이 감소되었고, 홀을 증가시키면 각각 약 0.398ms 0.6ms, 0.8ms의 연산시간이 감소되었다. 이를 바탕으로 hole이 2개인 경우 높은 정확도와 연산 수 절감을 통해 저전력 임베디드 비전 시스템을 구현할 수 있을 것으로 기대한다.

• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.187-195
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• 2023

Data centers not only consume significant electricity to operate IT equipment, but also use a lot of electricity to cool the heat generated by IT equipment. The waste heat of a high-temperature polymer electrolyte fuel cell (HT-PEFC) is capable of producing cooling , so it can be effectively applied to data centers that require cooling throughout the year. The energy-saving effects of the proposed combined cooling, heat and power (CCHP) system using HT-PEFC. That was analyzed based on the annual energy consumption data of a specific data center. When the system was running at 100% of the year, It was shown that the installation of 1 MW of the proposed system can save 3,407 MWh of electrical energy per year. In addition, compared to the existing system, the annual power usage effectiveness can be improved from 2.0 to 1.57 and 6,293 MWh of extra heat energy per year can be produced to sell. Furthermore, sensitivity analysis was performed on the fuel cell operating temperature and current density to guide the appropriate installation capacity of the proposed system.

• 대한기계학회논문집B
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• 제36권2호
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• pp.137-143
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• 2012

현재 세계적으로 배출가스 규제 강화와 유가 상승으로 인해 가솔린엔진에서 배출되는 유해 배출 가스 저감기술 및 연비향상 기술 개발이 절실히 요구되고 있다. 가솔린 직접분사(GDI; Gasoline direct injection) 기술은 가솔린 연료를 직접 연소실에 분사하여 정밀한 연소제어를 통해 매우 희박한 혼합기에서도 고효율의 연소가 가능하게 함으로써 연비저감과 고출력을 동시에 만족할 수 있는 효과적인 기술이다. 본 연구에서는 분무유도방식(spray-guided type)을 이용한 GDI 엔진을 개발하여 안정적인 희박연소를 구현하였다. 자주 사용되는 운전영역에서 연료분사시기의 TDC(Top dead center) 인근으로의 지각을 통하여 안정적인 희박연소를 구현하였으며, 다단분사를 적용하여 추가적인 연료소비율의 개선이 가능한 반면 탄화수소(THC)와 질소산화물($NO_x$)의 배출은 증가하고 CO의 배출은 감소되었다.

• 한국IT서비스학회지
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• 제14권3호
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• pp.183-196
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• 2015

The concept of energy-efficient networking has begun to spread in the past few years, gaining increasing popularity. A common opinion among networking researchers is that the sole introduction of low consumption silicon technologies may not be enough to effectively curb energy requirements. Thus, for disruptively boosting the network energy efficiency, these hardware enhancements must be integrated with ad-hoc mechanisms that explicitly manage energy saving, by exploiting network-specific features. The IEEE 802.3az Energy Efficient Ethernet (EEE) standard is one of such efforts. EEE introduces a low power mode for the most common Ethernet physical layer standards and is expected to provide large energy savings. However, it has been shown that EEE may not achieve good energy efficiency because mode transition overheads can be significant, leading to almost full energy consumption even at low utilization levels. Coalescing techniques such as packet coalescing and interrupt coalescing were proposed to improve energy efficiency of EEE, but their implementations typically adopt a simple policy that employs a few fixed values for coalescing parameters, thus it is difficult to achieve optimal energy efficiency. The paper proposes adaptive interrupt coalescing (AIC) that adopts an optimal policy that could not only improve energy efficiency but support performance. AIC has been implemented at the sender side with the Intel 82579 network interface card (NIC) and e1000e Linux device driver. The experiments were performed at 100 M bps transfer rate and show that energy efficiency of AIC is improved in most cases despite performance consideration and in the best case can be improved up to 37% compared to that of conventional interrupt coalescing techniques.

• 한국컴퓨터정보학회논문지
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• 제13권5호
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• pp.219-227
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• 2008

제약만족문제(Constraint Satisfaction Problem)의 연구에서 밝혀졌듯이, 제약최적화 문제(Constraint Optimization Problem)를 효율적으로 풀기 위해서는 변수순서화의 경험적 방법이 매우 중요하다. 이기종이 혼합된 무선 센서 네트웍의 에너지 효율적인 집단화 같은 문제는 클러스터 헤드가 기지국에 가깝게 위치하려는 경향이 있다. 본 논문은 이 집단화 문제를 풀기 위해서 정적 우선순위 변수 순서화에 기반을 둔 새로운 접근방법을 제시하고. pnode 라는 새로운 알고리즘을 제안한다. 이 pnode 알고리즘은 우선순위가 가장 높은 변수를 다음 변수로 선택한다. 집단화문제에 있어서 우선순위가 높다는 것은 클러스터 헤드가 최적지역에 근접하게 된다는 것을 의미하며 이것은 문제의 성격상 미리 정해진다. 클러스터화 된 센서 네트웍에서 클러스터 헤드는 에너지 소비가 가장 많이 일어나는 곳이기 때문에 센서 노드뿐만 아니라 클러스터 헤드에서 발생하는 최대 에너지 소비를 최소화하도록 만드는 방법을 찾는 것이 본 논문의 목적이다. pnode알고리즘을 사용하여 시뮬레이션 한 결과 제안된 방법이 다른 방법들보다 우수함을 알 수 있었다.

• 한국정보통신학회논문지
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• 제24권7호
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• pp.925-934
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• 2020

본 연구는 선박의 에너지 효율을 향상시키기 위하여 에너지 절감 시스템 (ESS, Energy Saving System)의 알고리즘을 선박운항 특성에 적합하게 설계하고, 특정 시스템을 탑재한 선박의 운항 특성을 바탕으로 에너지 소비 양상을 분석하여 운항 비용을 절감할 수 있도록 하는 기법에 대하여 연구한다. 이를 위해 발전체계를 기반으로 선박의 추진 체계 특성을 반영한 에너지 효율을 높일 수 있는 효율적인 시스템을 구현한다. 연구대상 선박은 LNG 운반선에 탑재된 HVACS(Heating, Ventilation and Air Conditioning) 대상으로 연구를 진행하며, 이를 기반으로 미래형 기반 선박인 전기추진선박 및 자율운항선박 등에 적용할 수 있도록 확장성을 가진 에너지 절감 기법을 제안한다.

• 유통과학연구
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• 제11권12호
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• pp.63-69
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• 2013

Purpose - Ethical consumption is the action of buying one product over another with an ethical idea in mind. It has gained in popularity since the 1990s with more emphasis being put on the power of consumer actions to create social, economic, and environmental change. Ethical consumption involves boycotts of certain products or brands as well as purchases linked to ethical issues. Cause-related marketing (the buying behavior of ethical consumption) involves a for-profit and non-profit entity teaming up to promote a product at the same time as promoting a social cause. Each time a consumer buys that product, a donation is made by the for-profit entity to the non-profit entity supporting the specific cause. Cause-related marketing has become a tremendously popular type of ethical consumption in recent years owing to its reputation of allowing companies to "do well by doing good." This study examines how consumers' perception of cause and attitude influence their attitude toward a cause-related marketing campaign and attempts to suggest implications for marketers. Research design, data, and methodology - First, this study was designed to examine the consumers' perception factors (cause involvement, attitude for cause, attitude for company and brand familiarity) in order to determine whether these factors have significantly affected consumers' attitude toward a cause-related marketing campaign. Second, this study developed a structural equation model and tested it empirically using survey data from 223 individual respondents. Respondents were undergraduate students in Chungnam. They were shown an existing real campaign message of cause-related marketing, and then filled out a questionnaire. Data were analyzed with SPSS 20.0 and AMOS 17.0 programs. Results - The hypotheses were tested using factor analysis and structural equation modeling. The study's results showed that brand familiarity, attitude to the company and attitude to the cause significantly affected consumers' attitude toward the cause-related marketing campaign and performance. In particular, attitude to the cause was significantly related to attitude and performance of the cause-related marketing campaign. However, the hypothesis about cause involvement was not supported with the results indicating that cause involvement did not affect consumers' attitude toward the cause-related marketing campaign. The findings underline the importance of consumer perceptions of the cause and the company and their attitude to the cause. They point to the importance of individual differences that influence consumer perceptions of the cause, the company and brand familiarity. Also of importance is the consumer's attitude to the cause. Conclusions - The findings suggest some practical implications in designing and implementing cause-related marketing campaigns. It is important to enhance brand familiarity and create a favorable attitude to the company and attitude to the cause before designing cause-related marketing campaigns. The rising popularity of cause-related marketing has been attributed to its potential to cut through advertising clutter. The findings in this study suggest that marketing campaigns supporting a cause make a difference.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.32-37
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• 2011

Biodiesel fuel is already remarkable alternative fuel in many countries. So, many studies are performed on the environmental or economic effects as well as the characteristics of diesel engine fueled biodiesel in combustion and emission. In this study, an CRDI diesel engine used to commercial vehicle was fueled with diesel fuel and 20% biodiesel blended fuel (BDF 20%) with city mode in excess of 300 hours. Engine dynamometer testing was completed at regularly scheduled intervals to monitor the engine performance and exhaust emissions. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. To check the engine parts (valve and injector), the engine was inspected after test. It was concluded that there were no unusual deteriorations of the engine, or any unusual changes in engine power and exhaust emissions in spite of operation of 300 hours with BDF 20%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.533-536
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• 2005

In this paper, a new drive system(SHS) for hybrid electric vehicle is proposed. As dual rotor hybrid electric vehicle using planetary gearsets, the SHS has the advantages of both series and parallel systems. The output speed and torque of SHS can be determined at specific point regardless of the engine's operating point. When the size of generator which is used in SHS is same as in THS, the SHS has more activities of engine control due to the ability that is operated in lower speed range. To maximize the performance of system, we carried out optimization for the three parameters that are engine, motorl and motor2. As the result of the optimization, we confirmed the SHS is more preferable to THS in fuel consumption and acceleration area.

• Journal of Biosystems Engineering
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• 제31권2호
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• pp.115-120
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• 2006

Our environment is faced with serious problems related to the air pollution from diesel engines in these days. In particular, the exhaust emissions of agricultural diesel engines are recognized main cause which influenced environment strongly. In this study, the potential possibility of biodiesel fuel was investigated as an alternative fuel for a naturally aspirated agricultural D.I. diesel engine. The smoke emission of biodiesel fuel was reduced remarkably in comparison with diesel fuel, that is, it was reduced approximately 50% at 2500 rpm, full load. But, power, torque and brake specific energy consumption didn't have large differences. But, NOx emission of biodiesel fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation (EGR) on the characteristics of NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel (20vol-%) and cooled EGR method($5{\sim}15%$) in an agricultural D.I. diesel engine.