• 수산해양기술연구
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• 제28권2호
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• pp.191-196
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• 1992

This paper is an experimental study to investigate utility of ultrasonic treatment of fuel oil in diesel engine. Experiment was carrid out to clarify the effect of ultrsonic vibration on the characteristics of maximum pressure, fuel consumption ratio, smoke, BMEP and torque. The result obtained are as follows: 1. In the case of given ultrsonic vibration, the maximum pressure is increased in all experimental conditions. 2. In the case of given ultrsonic vibration, the decrease effect of fuel consumption rate is increased at low rpm. 3. The generation quantity of soots is increased according to load. In the case of given ultrsonic vibration, the decreased quantity of soots does not very according to load. 4. In the case of given ultrsonic vibration, the BMEP and torque are increased at low load.

• 산업기술연구
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• 제14권
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• pp.109-117
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• 1994

To satisfy the requirement for the precision and productivity of machine tools, we need the technique to predict the surface roughness of workpiece under various cutting conditions. The surface roughness is mainly influenced by the ideal roughness i. e., the roughness by feeding quantity and geometry of the tool. In this paper, the surface roughness is divided into three zones and the mathematical models of the three zones are obtained, in consideration of the feeding conditions and tool geometry. Using the mathematical models, we developed a program to calculate the maximum feeding quantity satisfying the required surface roughness of the workpiece. The program is used to calculate the maximum feed for two kinds of the bites used under the real cutting condition.

• 한국물환경학회지
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• 제23권3호
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• pp.385-390
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• 2007

Reliable flow measurement for dry season is very important to set up the in-stream flow exactly and total maximum daily load control program in the basin. Especially, in the points which tidal current effects are dominant because reliability of the low measurement decrease. The reliable measuring methods are needed. In this study, we analysis the water surface elevation difference of water surface elevation. Quantity relationship to consider tidal currents in these regions. It is known that tidal current effects from Nakdong river barrage are dominant in Samrangjin measuring station. We developed multiple regression equation with water surface elevation, quantity, and difference of water surface elevation and compared these results water measured rating curve. All of these regression equation including linear regression equation and log regression equation fits better measured data them existing water surface elevation quantity line and Among three equations, the log regression equation is best to represent the measured the rating curve in Samrangjin point. The log regression equation is useful method to obtain the quantity in the regions which tidal currents are dominant.

• Journal of Biosystems Engineering
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• 제27권4호
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• pp.327-334
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• 2002

In this study, energy conversion from thermal energy to mechanical power by using n-pentane was tested and exergy variation, cycle number, water quantity pumped and thermal efficiency were analyzed. The energy conversion was done and the water head could be ten meters on the experimental conditions. The operating temperature range of cycle was recommended to be around the liquid-vapour saturation temperature of the working fluid on the viewpoint of the maximum work. The cycle diagram was analyzed by the exergy analysis. For the constant water head, the cycle number was decreased and the water quantity per day was increased and thermal efficiency become higher when the water quantity per cycle become increasing. For the constant pumping water quantity per cycle, cycle number and the water quantity per day was decreased and the thermal efficiency become higher because the saturation temperature become higher when the water head become higher.

• 한국자동차공학회논문집
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• 제23권6호
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• pp.623-632
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• 2015

This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

• 물과 미래
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• 제17권3호
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• pp.197-209
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• 1984

본 연구는 해안제방의 설치에 따른 제방전면의 변형과 제각부의 국소적 지형변동량을 알고자 해운대의 해양조사와 2차원 수리모형실험을 행한 것이며 제방의 설치위치, 해빈경사와 파랑의 특성에 따른 제방제각부의 최대선굴심, 1차경향범위, 최대변동량, 최대변량량까지의 거리 및 2차영향범위의 값들을 구명하여 이들 지형변동량을 줄일 수 있는 해운대해수욕장의 침식대책공법에 이바지 하고자 한다.

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.71-79
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• 1997

In this paper, operations system was designed for the centralization of data processing of various state information from the facilities of mobile communication network. And the system performance experimental system module was measured and analyzed from the designed experimental system module. The configuration of system design was presented with the centralized type to monite and control the facilities of mobile communication network in the central office. The communication process design of the internal system was implemented with the resource of message queue having a excellent transmission ability for processing of a great quantity of information in the inter-process communication among communication resources of UNIX system. The process with a server function from the internal communication processes was constructed with a single server or a double server according to the quantity of operations and implemented with the policy of the presented server. And then, we have measured performance elements in accordance with the change of input parameters from the designed experimental module : response time, waiting time, buffer length, the maximum quantity existing in message queue. And from these results, we have compared and analyzed the system state each server algorithm according to performance variations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.5-6
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• 2012

In this paper, a simplified maximum power point tracking technique for the solar charger is presented. Main advantages of the proposed charger include low cost and optimized charge time. The maximum power point tracking method is used to deliver the maximum power from PV array to the battery thereby reducing the charge time. Moreover, the proposed technique which tracks the maximum power point by adjusting output current helps reduce the quantity of required number of sensors for the charger. The experimental protype was implemented by using an 80W PV array, a buck converter and a digital signal processor to verify the feasibility of the proposed method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1068-1072
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• 1997

This work deals with on investigation the influence of various additives to a base stock cutting fluid in order to develop a better deep hold drilling. This investigation has been aiming at developing an oil which gives a maximum cutting efficiency at a minimum wear rate of the tool and the guiding pads. The purpose of study is to analyze how guide pad of tools, workpiece and the change of contained quantity of extreme pressure additive in cutting fluids have effects on the hold over size of cutting hole, surface roughness of workpiece,wear rates of guide pad and roundness during the deep hole machining of SM55C with solid BTA drill by using BTA drilling system through experiment. Conclusion reached is as follows. It has been proved that the contained quantity of surphur more affects machinability than that of extreme pressure additive of chlorine of cutting fluid in BTA drilling during Deep Hole Drilling. Considering its base oil, the the contained quantity of extreme pressure assitive of surphur can be different, but it's judged that the range of 1.5 ~ 2.0% is suitable to machinability for workpiece in BTA drilling. Regarding guide pad, it's judged that the reduction of wear is possible in propotion to the contained quantity of exrreme pressure additive of chlorine against supporting of cutting force and Bumishing operation of machining parts in cutting.

• 정보처리학회논문지D
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• 제12D권7호
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• pp.1031-1038
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• 2005

본 논문에서는 시스템 사용현황을 파악할 수 있는 데이터를 최대수용 트래픽양과 실제 트래픽량으로 구분해서 측정하며 프로토콜 변경에 따른 트래픽량 변화와 사고발생시의 과부하 조건에서의 트래픽을 분석할 것이다. 이로 인해 전력감시제어설비의 안전성을 극대화할 수 있는 계기를 미련하고자 한다 또한, 현재 유통되고 있는 트래픽이 어느 정도인지를 알고 그 증가율 추세를 파악하여 앞으로 예상되는 트래픽량을 미리 예측하여 필요한 대역폭을 미리 확보하는 자료로 활용하고, 네트워크 정보분석을 통한 한정된 네트워크 자원의 효율적인 배치로 안정된 전력감시페어시스템의 운용을 가능하게 함으로써 신뢰성을 향상시킬 수 있다.