• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2597-2602
• /
• 2007

In this paper, the performance analysis is experimentally carried out in order to select the best cooling fan and shroud considering both cooling performance and noise reduction. 4 cooling fans have been tested in the fan tester and the real excavator. In order to obtain the performance of the cooling fans, flow capacity has been estimated by measuring flow velocity using a hot wire anemometer, and noise radiation has been also measured to estimate the fan noise. Characteristics of a box-type and a streamlined shroud have been examined by changing the immersion depth of cooling fans. Based upon the results, the best cooling fan is selected. Finally, the criterion to select the best cooling fan has been set up.

• Journal of Educational Research in Mathematics
• /
• v.8 no.1
• /
• pp.31-39
• /
• 1998

In this study the types of strategies, the reasonable method of the selection of the problem for the recognition of the strategies and the presentation of the problems based on the types of the strategies are explored. The strategies can be used in elementary, middle or high school mathematics. But it can't be expected that students use the strategies unfamiliar to them, so it is necessary to select the strategies applicable according to the degree of the student's affective and cognitive abilities. And it is desirable to select the problems for the recognition of the strategy such as nonroutine problems and open-ended problems, but more study is needed in these areas.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.955-957
• /
• 2005

대용량의 텍스트에 대해 빠른 패턴 검색의 필요성이 증가함에 따라 써픽스 트리, 써픽스 배열 등의 인덱스 자료구조에 대해 다양한 연구들이 진행되었다. 또한 써픽스 배열을 대용량의 인덱스 자료구조로 사용하기 위해 저장 공간을 O(n log n) 비트 이하로 줄이는 문제에 대한 연구들도 많이 수행되었다. 이들 중 Grossi & Vitter 는 써픽스 배열을 압축하여, 기존의 써픽스 배열보다 작은 저장 공간을 사용할 수 있는 알고리즘을 제안하였다. Grossi & Vitter 알고리즘은 압축된 써픽스 배열에서 실제 써픽스 배열의 정보를 찾기 위하여, succinct 표현에서 기본적으로 사용되는 rank와 select 함수를 필요로 한다. 본 논문은 다양한 rank와 select 알고리즘을 각각 사용하는 압축된 써픽스 배열들의 성능 비교를 통해, succinct 표현의 효율적인 구현이 압축된 써픽스 배열의 성능에 미치는 영향을 실험적으로 보인다.

• Ocean Systems Engineering
• /
• v.2 no.2
• /
• pp.83-97
• /
• 2012

In the present work, design procedure and computer simulation of an AUV are documented briefly. The design procedure containing the design of propulsion system and CFD simulation of hydrodynamics behavior of the hull leads to achieve an optimum mechanical performance of AUV system. After designing, a comprehensive one dimensional model including motor, propeller, and AUV hull behavior simulates the whole dynamics of AUV system. In this design, to select the optimum AUV hull, several noses and tails are examined by CFD tools and the brushless motor is selected based on the first order model of DC electrical motor. By calculating thrust and velocity in functional point, OpenProp as a tool to select the optimum propeller is applied and the characteristics of appropriate propeller are determined. Finally, a computer program is developed to simulate the interaction between different components of AUV. The simulation leads to determine the initial acceleration, final velocity, and angular velocity of electrical motor and propeller. Results show the final AUV performance point is in the maximum efficiency regions of DC electrical motor and propeller.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.15 no.4
• /
• pp.307-318
• /
• 2011

We introduce an algorithm that automatically generates paper templates of a triangulated surface. The surface can be built by cutting, folding, and pasting the paper templates. The algorithm is branched to two strategies : one is to select the longest neghboring edge among many choices, and the other is to select the largest neighboring triangle. Three surfaces, whose triangulation sizes widely range, are successfully built by the algorithm. The two strategies are empirically evaluated in building the surfaces with respect to paper consumption, a measure of cost efficiency, and boundary length, a measure of speed efficiency. Strategy 1 performs in most cases better than the other one with respect to boundary length, but sometimes wins and sometimes loese with respect to paper consumption.

• ETRI Journal
• /
• v.42 no.4
• /
• pp.585-595
• /
• 2020

Integration of multiple communication technologies in a smart grid (SG) enables employing cognitive radio (CR) technology for improving reliability and security with low latency by adaptively and effectively allocating spectral resources. The versatile features of the CR enable the smart meter to select either the unlicensed or the licensed band for transmitting data to the utility company, thus reducing communication outage. Demand response management is regarded as the control unit of the SG that balances the load by regulating the real-time price that benefits both the utility company and consumers. In this study, joint allocation of the transmission power to the smart meter and consumer's demand is formulated as a two stage multi-armed bandit game in which the players select their optimal strategies noncooperatively without having any prior information about the media. Furthermore, based on historical rewards of the player, a real-time pricing adaptation method is proposed. The latter is validated through numerical results.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1589-1592
• /
• 1997

Among the prerequisite abilities (perception of environment, path planning and position estimation) of an autonomous mobile robot, position estimation has been seldom studied by mobile robot researchers. In most cases, conventional positioin estimation has been performed by placing landmarks or giving the entrire environmental information in advance. Unlikely to the conventional ones, the study addresses a new method that the robot itself can select distinctive features in the environment and save them as landmarks without any a priori knowledge, which can maximize the autonomous behavior of the robot. First, an orjentaion probaility model is applied to construct a lcoal map of robot's surrounding. The feature of the object in the map is then extracted and the map is saved as landmark. Also, presented is the position estimation method that utilizes the correspondence between landmarks and current local map. In dong this, the uncertainty of the robot's current positioin is estimated in order to select the corresponding landmark stored in the previous steps. The usefulness of all these approaches are illustrated with the results porduced by a real robot equipped with ultrasonic sensors.

• Proceedings of the IEEK Conference
• /
• 2001.06c
• /
• pp.213-216
• /
• 2001

Key frame extraction is an important method of summarizing a long video. This paper propose a technique to automatically extract several key frames representative of its content from video. We use the color layout descriptor to select key frames from video. For selection of key frames, we calculate similarity of color layout features extracted from video, and extract key frames using similarity. An important aspect of our algorithm is that does not assume a fixed number of key frames per video; instead, it selects the number of appropriate key frames of summarizing a long video Experimental results show that our method using color layout descriptor can successfully select several key frames from a video, and we confirmed that the processing speed for extracting key frames from video is considerably fast.

• Proceedings of the IEEK Conference
• /
• 2000.11d
• /
• pp.61-64
• /
• 2000

The purpose of this study is prove the effectiveness of an energy subtraction image for the detection of pulmonary nodules and the effectiveness of multi-resolutional filter on an energy subtraction image to detect pulmonary nodules. Also we examine influential factors to the accuracy of detection of pulmonary nodules from viewpoints of types of images and evaluation methods. As one type of images, we select energy subtraction X-ray images, at the same time is done ▽$^2$G filter and multi-resolutional filter. Here select two evaluation methods and make clear the effectiveness of multi-resolutional filter on an energy subtraction image.

• Journal of Information Processing Systems
• /
• v.13 no.3
• /
• pp.500-517
• /
• 2017

In this paper, an improved zone-based routing protocol for heterogeneous wireless sensor networks is proposed. The proposed protocol has fixed the sized zone according to the distance from the base station and used a dynamic clustering technique for advanced nodes to select a cluster head with maximum residual energy to transmit the data. In addition, we select an optimal route with minimum energy consumption for normal nodes and conserve energy by state transition throughout data transmission. Simulation results indicated that the proposed protocol performed better than the other algorithm by reducing energy consumption and providing a longer network lifetime and better throughput of data packets.