• 한국정보과학회논문지:시스템및이론
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• 제29권3호
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• pp.153-160
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• 2002

본 논문에서는 인터넷 광고에서 웹사이트를 방문하려는 고객과 서버들간에 상호작용을 측정하기 위한 안전하고도 효율적인 측정 방법에 관해 고려한다. 대개의 인터넷 광고는 많은 고객들과 서버들 그리고 서버들에 의해 제공되는 고객들의 수에 관한 측정 정보를 수집하는 감사 기관의 상호작용으로 이루어진다. 측정 방법은 항상 고객의 방문 횟수를 과장되게 조작하려는 서버의 악의 있는 시도라든가 측정 과정을 붕괴하려는 고객들의 시도로부터 항상 안전해야만 한다. 따라서, 본 논문에서는 여러 암호학적인 기법들에 기반하여, 안전하고 효율적이며 정확하고 강건한 측정 방법을 제안하고자 한다.

• 드라이브 ㆍ 컨트롤
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• 제15권1호
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• pp.1-9
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• 2018

The spool displacement of directional control valve can be considered as the standard signal to measure the bandwidth frequency of a directional control valve. When the spool displacement is not available, the metering-orifice system is implemented in this research as an alternative way of measuring the 90 degrees phase bandwidth frequency of the hydraulic directional control valve. The inertia effect on the transmission line oil induces the phase lead of the valve load pressure when compared with the phase of spool displacement. The capacitance effect of the oil induces the phase lag of the valve load pressure. The phase of the load pressure can be adjusted to be the same as that of the spool displacement by controlling the opening area of the metering orifice. A series of experiments were conducted to verify the effectiveness of the metering orifice. The 90 degrees phase bandwidth frequency measured from the valve load pressure was significantly deviated in some cases from the frequency of the spool displacement. The metering orifice was hard to be applied to measure the -90 degrees phase bandwidth frequency of the high precision.

• Journal of Biosystems Engineering
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• 제27권6호
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• pp.547-556
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• 2002

Upright positioning of garlic cloves in mechanical planting has been considered as an essential process because pose of garlic affects not only initial budding and rooting of garlics but quality and yield. Due to the geometrical uniqueness and irregularity of garlic cloves in shape, manual planting operation has been conducted. The overall objective of this research was to determine design factors for designing a garlic clove planter The results are summarized as follows : 1. A vibrating-type clove-metering device was designed and tested. Effects of tilted angle of metering plate and magnitude of vibration on metering performance were investigated. The successful planting rates of the metering device were 96.7% for Hanji varieties. 2. Clove upright-positioning device, posture inducer was designed and tested. When the clearance between the hoppers was set at 4mm, the rates of upright positioning of the device were 92.2% for with Hanji varieties. 3. Optimum metering performance was observed at the plate tilted angle of 80。 with the posture type positioning device.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.308-310
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• 2001

With the development of Computer & Communication Technology, nowadays many people are interested in remote metering, and many vendors are suggesting various remote metering solutions. KEPCO (Korea Electric Power Corporation) adopts some of these to some customers who uses a lot of electric power, also continues researching them. But, currently used electronic watt-hour meters vary in terms of communication protocol and data structure by the vendors. So we have to know each vendor's communication protocol and data structure to construct a remote metering system, or to find problems in it. But that's impossible to know each vendor's protocol and data structure because they are reluctant to tell those to outside the company. To solve these problems and to make a much more cost-effective metering system, KEPCO developed standard communication protocol between meters and PC (or metering server), and defined standard functions and data structure which can be used by everyone easily. Those developments support standard interface for every vendors' meters. And Those will be adopted by KEPCO for a part of a new metering standard for electronic watt-hour meters.

• 한국항공우주학회지
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• 제34권9호
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• pp.76-81
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• 2006

본 논문에서는 공기흡입식 추진기관용 연료공급 시스템의 연료조절 밸브 시스템을 제안하였으며, 제안된 시스템은 서보밸브에 의해 구동되는 차압유지 밸브와 미터링 밸브로 구성되어 있다. 시스템 성능 및 안정성에 영향을 미치는 인자를 찾기 위해 비선형 및 선형 해석을 수행하였다. 이를 통해 미터링 밸브 오리피스 양단의 차압 유지량 ${\Delta}P$가 시스템 안정성에 영향을 미침을 예측하였고 실험 및 비선형 전산모사를 통하여 입증하였다. 해석 및 실험 결과차압 유지량 ${\Delta}P$를 줄이고 동시에 이등변 삼각형 형상의 오리피스를 차압유지 밸브에 적용함으로써 요구 유량에 따라 유량이득이 조절되도록 하여 시스템의 안정성을 높일 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1398-1406
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• 2018

Owing to the consistent increase in accurate analysis issue for energy consumption of the AC electric railway systems, there is controversy about the adequacy of the present watt-hour metering configuration. Due to the unusual load characteristics and facilities, the discussions have not been active. Therefore, in order to achieve more accurate watt-hour metering for AC electric railway system, this paper proposes numerical formulas for watt-hour metering that reflects the highly-varying characteristics of the railway load and the structural characteristics of the Scott transformer. The proposed formulas have been verified by comparison with site-measured data, and a more suitable metering configuration for AC railway system has been proposed.

• ETRI Journal
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• 제45권4호
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• pp.650-665
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• 2023

A novel smart metering technique capable of anomaly detection was proposed for real-time home power management system. Smart meter data generated in real-time were obtained from 900 households of single apartments. To detect outliers and missing values in smart meter data, a deep learning model, the autoencoder, consisting of a graph convolutional network and bidirectional long short-term memory network, was applied to the smart metering technique. Power management based on the smart metering technique was executed by multi-objective optimization in the presence of a battery storage system and an electric vehicle. The results of the power management employing the proposed smart metering technique indicate a reduction in electricity cost and amount of power supplied by the grid compared to the results of power management without anomaly detection.

• 한국항만학회지
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• 제13권2호
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• pp.333-350
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• 1999

Today freeway is thought to be a very important transportation facility carrying tremendous traffic flow as the main corridor within the area of between the areas. However freeway is experiencing severe congestion and accidents by increased entrance ramp flow especially at peak time period. Ramp meters on the freeway entrance ramps that supply traffic to the freeway in a measured or appropriately regulated amount are needed for alleviating freeway congestion. Because ramp meters can be operated to discharge traffic at a measured or regulated rate thus maintaining more uniform speed on the mainline section maximizing the throughput to the freeway within the capacity of a downstream bottleneck and reducing the congestion related accidents. Thus the objectives in this study were to analyze the traffic characteristics on the freeway I-94 with ramp metering system before/after ITS technology in Detroit (Michigan) area compare shifts of the traffic characteristics on the freeway I-94 before/after ITS technology and finally suggest a better ramp metering strategy for the freeway system The following results were obtained: i)Flow occupancies and speeds on the mainline merge section of freeway were shown to be a big difference depending on the peak periods areas and directions based on the distribution of traffic flow characteristics on the freeway. ii)Reduced speed was shown to be more than 5 mph and ramp flow was also shown to be more than 240 vph at peak periods if there was the ramp metering system constructed on the freeway. iii)Ramp metering system was shown to be optimally operated on the freeway if ramp flow could be maximized within the range of over 900 vph and reduced occupancy could be also maximized by no more than 2 percent at peak periods. iv)The average flows on the freeway after the ITS technology were shown to be a decrease of over 20% depending on the peak periods areas and directions when compared with those flow on the freeway before the ITS technology. over 20% depending on the peak periods areas and directions when compared with those speeds on the freeway before the ITS technology. vi)The average metering rates on the freeway after the ITS technology were shown to be an increase of over 10% depending on the peak periods areas and directions when compared with those metering rates on the freeway before the ITS technology.

• 한국도로학회논문집
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• 제14권2호
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• pp.175-181
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• 2012

회전교차로(roundabout)는 용량 이하의 상태에서 접근로별 교통류가 균등할 경우 기존 신호교차로에 비해 운영효율성이 증대되나 토지이용변화로 교통량이 증가하면서 접근로별 교통류가 불균등 해질 경우(차로 당 450대/시 이상) 주접근로에서 회전교차로 내부로의 진입이 어려워져 효율성이 떨어지게 된다. 본 연구에서는 1차로형 4지 회전교차로를 대상으로 회전교차로 설치이후 교통량 증가로 신호교차로 설치에 대한 재검토를 하기 전에 회전교차로를 효율적으로 운영할 수 있는 Signal Metering 전환기준 및 운영방법을 제시하고 효과분석(지체 및 대기행렬)은 SIDRA를 활용하였다. 본 연구결과 총 진입교통량이 1,800~2,000pcu/시 이고 주접근로의 진입교통량비가 60~70%일 때 지체는 30~40% 그리고 대기행렬은 30~60% 감소하였다. 또한 주접근로에 가장 인접한 부접근로에 Metered Approach를 설치하고 한 쌍(pair)으로 묶어서 운영하는 것이 효과적인 것으로 분석되었다.

• 한국도로학회논문집
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• 제15권5호
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• pp.217-226
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• 2013

PURPOSES : Under the capacity conditions with balanced approach flows, roundabouts give less delay than existing signalized intersections; however, flows over 450 vehicles/hour/lane with unbalanced approach flow conditions, roundabouts efficiency drops due to the short time difference between the critical gap and the follow-up headway. The purpose of this study is developing a roundabout Signal Metering operation method by considering approach lanes degree of saturation. METHODS : A four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of 16 different unbalanced flow conditions. Based on these traffic conditions, the performance is evaluated for 64 different cases of Signal Metering combinations by using SIDRA software. A degree of saturation(V/C ratio) sum for two adjoined approaches is used for the performance index of choosing Metered Approach and Controlling Approach. RESULTS : When the V/C ratio sum is 0.29~0.81 and Metered Approach flow is less than Controlling Approach flow, the average delay saving per vehicle is about 7 seconds; however, after this rage the delay saving decreases gradually until the V/C ratio sum reaches around 1.0. The range of V/C ratio sum 0.93~1.09 provides average delay saving per vehicle about 3 seconds. In case of V/C ratio sum is grater than 1.0 and the flows of Metered Approach is grater than Controlling Approach, the average delay per vehicle increases 3~11 times respectively. CONCLUSIONS : As expected, the Signal Metering provides substantial improvements in delay saving for the case of V/C ratio sum is 0.3~1.0 under the traffic flow conditions of Metered Approach is less than Controlling Approach.