• Journal of Environmental Science International
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• v.3 no.3
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• pp.229-239
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• 1994

By laying emphasis on the intermediate layer, water property distribution in the Northwest Pacific is studied using the hydrographic data obtained by Japan Meteorologica] Agency in the period from 1960 to 1986. The scattering of water type in T-S diagram is relatively small in the Kuroshio Region. Both the envelopes of saline side and of fresh side of the scattered data points shifts gradually from saline side to fresh side as the observation line moves from southwest to northeast. In the Mixed Water Region, the scattering of water type increases rapidly as the observation line moves north; The envelope of fresh cold side moves towards fresh cold side much faster than that of same side. The thermosteric anomaly value at the salinity minimum decreases as the observation line moves from north to south or southwest. This suggests that the water does not advect along the salinity minimum layer, but that the salinity minimun layer is understood as a boundary of two different waters aligned vertically. We defined the typical water masses for the Oyashio Water and the Kuroshio Water. The water mass below the salinity minimum layer may be created by isopycnal mixing of these two water masses with a fixed mixing rate. While, the water mass above the salinity minimum cannot be created simply by isopycnal mixing. The salinity minimum layer may be eroded from upper side due to active mixing processes in the surface layer, while the water of the salinity minimum layer moves gradually southward. This appears to give an explanation why the thermosteric anomaly value at salinity minimum decreases towards south.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.233-233
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• 2009

Piezoelectric Transformer (PT) was emerged in device and material industry. PT has some advantages such as low profile and mechanical energy transfer with little electromagnetic interface (EMI). But, It is known that the maximum PT efficiency can be obtained when it operates near the resonant frequency of the PT. Also PT's resonant frequency moves according to the load conditions Therefore, As the operating frequency moves further from the resonant frequency, the PT efficiency decreases dramatically due to the increase of the circulating current. This paper proposes analyzes modeling of PT convert and propose a guide-line to adaptive control

• Transactions of Materials Processing
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• v.18 no.7
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• pp.513-518
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• 2009

Large load is required in forging of large-scale components which becomes a critical restriction in practice. In the present study, two methods of incremental forging were investigated for the purpose of reducing the load required for forging of large and thick plates. The forging was applied primarily to obtain fine grains by imposing large amount of plastic deformation to the plates. One was to use nine strokes with a flat die and the other was to use three strokes with a curved die. The die moves vertically in the former while it moves vertically as well as rolls horizontally in the latter. Deformation of the slab in each case was analyzed by rigid-plastic finite element method and as a result, variations of load and slab holding force, and distributions of effective strain and thickness were predicted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.383-388
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• 2004

A piezoelectric actuator yields hysteresis effect due to its composed ferroelectric. Hysteresis nonlinearty is neglected when a piezoelectric actuator moves with short stroke. However when it moves with long stroke and high frequency, the hysteresis nonlinearty can not be neglected. The hysteresis nonlinearty of piezoelectric actuator degrades the control performance in precision position control. In this paper, in order to improve the control performance of piezoelectric actuator, an inverse modeling scheme is proposed to compensate the hysteresis nonlinearty problem. And feedforward - feedback controller is proposed to give a good tracking performance. The Feedforward controller is inverse hysteresis model, Nueral network and PID control is used as a feedback controller. To show the feasibility of the proposed controller and hysteresis modeling, some experiments have been carried out. It is concluded that the proposed control scheme gives good tracking performance

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1260-1263
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• 1987

This paper describes the mobile robot system to recognize the guidance tape, and presents the locomotion algorithm. This system converts video imago to binary image by setting an optimal threshold and obtains the parameters to move the robot. The mobile robot moves according to the programmed route in memory. But after recognized the obstacle on the locomotion routs, this system constructs the new route and the robot moves following the new route.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.53-59
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• 2010

In this study, an investigation of the shoreline changes at Song-do beach in Busan was carried out for a coastal improvement project to prevent damage from coastal disasters. From the results of the observed data, it is seen that the shoreline moves seaward under extreme wave conditions and moves leeward under normal wave conditions. The reason for this is wave run-up when wave conditions are extreme in summer. In addition, nourishment sand is moved seaward by wave run-up. Thus, the shoreline's slope is gently decreased. Therefore, the shoreline is moved seaward.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.738-749
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• 2003

Mobile IP protocol introduced in RFC3344 provides a node of the mobility service through IP tunneling mechanism in the IP networks. In this paper, we describe a method to provide a mobility service for VPN(Virtual Private Network) nodes on the MPLS(Multiprotocol Label Switching) network. The MPLS VPN considered here is based on "BGP/MPLS VPNs" presented in RFC2547. PE(Provider′s Edge) routers, which are able to provide VPN services on the MPLS network, are associated with mobility agents to support Mobile IP This proposed mechanism applies when a VPN node moves to other site of the same VPN, or when it moves to other site of a different VPN, or to the ordinary Internet site. We implemented this mechanism in PE routers and analyzed the performance of the MPLS VPN with mobility support on the testbed.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.104.3-104
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• 2002

A quadruped stair robot introduced here plays a role in monitoring and moving some place where an operator can not reach or when he may not keep watching. It has several features that travels and poses variable position by four caterpillars and quadruped typed arms, transmits an image and command data via RF wireless and network communication. The robot can balance itself when it moves up and down on a slope by using the quadruped mechanism. The robot vision scans ahead before it moves, and the captured image is transferred to a main computer via a RF image module. The main computer analyzes the obstacle, and when it is found the obstacle, the robot avoids from the obstacle and keep moving f...

• Journal of Korea Foundry Society
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• v.7 no.3
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• pp.199-206
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• 1987

This paper presents experimental data for the computerization of green sand control. The results can be summarized as follows: 1. To obtain the proper compactability at the mixer, the addtion of moisture is far more efficient than the control of mixing time or addtion of clay. 2. The log R(% clay/% moisture) vs. log compactability curve moves upward as the amount of clay increases and moves downward as the amount of seacoal, dead bentonite or coked seacoal increases. 3. The ratio of dead to initial clay amount or coked to initial seacoal amount is changed according to sand to metal ratio, mainly, and according to pouring temperature, partly, at a shake out time of 12hrs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.480-483
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• 1997

In this paper, we have proposed an automatic inspection system for cracks on the surface of a structure. The proposed system consists of the imaging system and the veh~cle system. The imaging system. a set of optical sensor, lens, illuminator, storage and their configuration, images the scene and store it on the hard disk. We adopted a linescan camera of 5000 pixel density to achieve high resolution without loss of simplicity. The vehicle system that moves the optical system IS ~mplemented by an AGV. The AGV moves forward at constant velocity and avoid obstacles to acquire a stable image. We have cmplemented an experimental system and have acquired images of the wall of hallway. The image is of 0.1-mmipixel resolution and the scanning time IS about 1 mlsec. The allow able scan.