• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1136-1137
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• 2007

현재 건설기계에 있어서 연비 절감에 대하여 유압 기기나 엔진의 에너지 손실 저감에 대한 대책이 있었으나 이것만으로는 한계가 있어 대폭적인 방안을 모색하는데 있어서 동력 시스템의 재검토가 필요한 시점이다. 더불어 자동차와 마찬가지로 건설기계에서도 배기가스 저감이나 연비 저감은 매우 중요한 과제이다. 그 해결책으로서 현재 자동차에서 개발된 하이브리드 시스템의 적용이 매우 유용하다 할 수 있다. 따라서 본 논문에서는 하이브리드 동력 시스템을 건설기계에 적용한 내용을 소개하고 있다. 건설기계의 하이브리드 동력 시스템을 구성하는 엔진, 발전기, 모터, 배터리, 커패시터 등의 전력전자 기기와 전동 유압을 구성하는 전동 유압 기기를 모델화 하여 하이브리드 동력 시스템을 적용한 건설기계의 기본적인 구조와 제어 성능을 파악하고 방식별 하이브리드 시스템의 성능을 비교하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.663-664
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• 2007

지중송전선로 건설공사에 154kV 장조장 케이블 드럼개발 및 트레일러 일체형 Under Roller 방식을 이용한 포설장비를 개발하여 현장에 적용함으로써 신기술 신개발 공법 적용으로 인한 국제경쟁력 향상 뿐만 아니라 접속경간의 장조장 설계로 케이블 접속개소 감소로 인한 공사비절감과 공사기간 단축에 크게 기여하였다. 이와 동시에 공사를 위한 도로점용 단축으로 민원발생을 크게 감소시켰다. 현행 도로법 규제로 케이블의 운반중량이 제한되었던 케이블 표준 경간을 450m에서 최대 700m까지 가능하여 접속개소의 유연성이 확보되었을 뿐만 아니라 토목구조물(전력구,관로등)공사의 다양한 설계방법을 적용할 수 있게 되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.172-180
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• 2013

In this paper, we propose an energy-efficient camera operating scheme to save energy which can be used for mass surveillance cameras. This technique determines how many cameras should be turned on in the consideration of the velocity vector of monitoring targets, which is acquired by DSRC object tracking, the model of the specification of installed cameras, and the road model of installed sites. Also, we address other techniques used to save energy for the surveillance system as well. Throughout performance evaluation, we demonstrate the excellence of our proposed scheme compared with previous approaches.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.817-838
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• 2005

In this paper, the resource adequacy as well as the optimum fuel mix is obtained by the following procedures. First, the regulation body, the government agency, determine the reliability index as well as the optimum portfolio of the fuel mix during the planning horizon. Here, the resources with the characteristics of public goods such as demand-side management, renewable resources are assigned in advance. Also, the optimum portfolio is determined by reflecting the economics, environmental characteristics, public acceptance, regional supply and demand, etc. Second, the government announces the required amount of each fuel-type new resources during the planning horizon and the market participants bid to the government based on their own estimated fixed cost. Here, the government announces the winners of the each auction by plant type and the guaranteed fixed cost is determined by the marginal auction price by plant type. Third, the energy market is run and the surplus of each plant except their cost (guaranteed fixed cost and operating cost) is withdrew by the regulatory body. Here, to induce the generators to reduce their operating cost some incentives for each generator is given based on their performance. The performance is determined by the mechanism of the performance-based regulation (PBR). Here the free-riding performance should be subtracted to guarantee the transparent competition. Although the suggested mechanism looks like very regulated one, it provides two mechanism of the competition. That is, one is in the resource construction auction and the other is in the energy spot market. Also the advantages of the proposed method are it guarantee the proper resource adequacy as well as the desired fuel mix. However, this mechanism should be sustained during the transient period of the deregulation only. Therefore, generation resource planning procedure and market mechanisms are suggested to minimize possible stranded costs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.632-637
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• 2016

A streetlight control system was developed using information technology and LED lights for efficient management and energy savings. The proposed system can control the power usage of an LED streetlight luminaire using GPS satellite communication and an Arduino with a built-in microprocessor. A control circuit was designed to control the current using GPS, a control unit, transistor, resistor, and constant-current supply circuit. The circuit was validated through experiments with normal operation. Using GPS, the control system extracts accurate time and location information according to the season, and it controls the current supplied to the LED streetlight according to the extracted time. Power consumption was reduced by more than 11%. The control system could reduce accidents caused by conventional lighting systems used to save energy, and it could improve the inefficient management of energy by preserving constant brightness of a streetlight at times and in areas that have less traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.203-208
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• 2018

In this paper, we selected power and power distribution facilities corresponding to urban infrastructure from the types of damage that could be caused by earthquakes and studied how they were calculated to damage. To calculate the damage, a graph of the magnitude of the damage was produced by applying the vulnerability curve calculation formula, which can be calculated for each type and type of facility. The scale of the earthquake and the probability of the occurrence of damage by the maximum earthquake acceleration were shown in the form of a vulnerability rate when the earthquake occurred in the urban infrastructure facility for utilizing the calculation result. It also applied a method of quantifying the fragility, which is a method of converting the calculated fragility into an integrated form, to represent a constant value for the magnitude of the damage. Continuing research, such as the method applied in this paper, could help identify in advance the types of structures affected by an earthquake and respond to reducing damage.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.1
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• pp.35-38
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• 2015

LEDs are considered to be an alternative for enhancement of energy efficiency, applied for numerous areas such as display, automotive headlight not only lights. Yellow phosphor is generally utilized with blue LEDs to generate WLED, $Y_3Al_{5}O_{12}:Ce^{3+}$ is typically used as the yellow phosphor. The phosphor, mixed with epoxy resin, has been used by being spread and hardened on the blue LED chip. This paste-based packaging gives rise to problems of degradation of phosphor by heat and decrease of luminous efficiency. Although phosphor plate is used instead of the epoxy-phosphor mixture to solve these problems, loss of luminous efficacy by total internal reflection inside the plate also should be solved. In this study, we coated the side of the plate with silver as one of the solution.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.493-499
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• 2022

The standards pertaining to the quality of discharged water in sewage treatment plants are strengthening, and accordingly, facilities in sewage treatment plants are being upgraded. In addition, the discharge water quality of sewage treatment plants must be maintained at a high level, and efficient sewage treatment plant operations have thus emerged as a very important issue. For the efficient operation of sewage treatment plants, this study applied a basic blowing amount calculation method based on sewage facilities to evaluate the required oxygen amount and blowing amount according to inflow water quality by logicizing various influencing factors. As a result of calculating the amount of air blown by applying actual April water quality data from sewage treatment plant A to the blower demand calculation developed through this study, it was found that the average amount of air blown was reduced by about 12%. When the blower demand calculation developed here is applied to an actual sewage treatment plant, the amount of air blown can be controlled based on the inflow water quality. This can facilitate the realization of an autonomous control of sewage treatment plants, in contrast to the existing sewage treatment operation method that relies on operational experience of operator. In addition, it is expected that efficient sewage treatment plants can be operated by reducing blowing amounts and power costs, which will contribute to both energy and carbon savings.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.11-20
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• 2008

IEEE 802.16e has adopted sleep mode to minimize energy consumption of mobile nodes with high speed mobility. If the Base Station (BS) has no data to be sent to a Mobile Subscriber Station (MSS) at the instant of ending sleep window of the MSS, the MSS increases its sleep window interval by double until the window interval reaches to the maximum sleep window interval. Thus, during the operation of sleep mode, MSS repeatedly performs switch on/off action until there exist frames to be received from BS. The switch on/off operation significantly consumes energy of MSS. To effectively deal with the energy of the MSS, this paper proposes an algorithm which decides the minimum sleep window interval that will be used in next sleep mode based on the current sleep window interval. We evaluate the performance of IEEE 802.16e sleep mode algorithm and our proposed algorithm in terms of energy consumption and blocking probability. Compared with the current sleep mode algorithm used in IEEE 802.16e, the proposed algorithm decreases the energy consumption by about 30% without increasing blocking probability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.96-103
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• 2008

This paper proposes a new low-power and small-area Reed-Solomon decoder. The proposed Reed-Solomon decoder using a novel simplified form of the modified Euclid's algorithm can support low-hardware complexity and low-Power consumption for Reed-Solomon decoding. The simplified modified Euclid's algorithm uses new initial conditions and polynomial computations to reduce hardware complexity, and thus, the implemented architecture consisting of 3r basic cells has the lowest hardware complexity compared with existing modified Euclid's and Berlekamp-Massey architectures. The Reed-Solomon decoder has been synthesized using the $0.18{\mu}m$ Samsung standard cell library and operates at 370MHz and its data rate supports up to 2.9Gbps. For the (255, 239, 8) RS code, the gate counts of the simplified modified Euclid's architecture and the whole decoder excluding FIFO memory are only 20,166 and 40,136, respectively. Therefore, the proposed decoder can reduce the total gate count at least 5% compared with the conventional DCME decoder.