• Journal of Industrial Technology
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• v.17
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• pp.11-20
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• 1997

This paper deals with the study on the cutting characteristics in ball endmilling process. First of all, the effects of the geometric cutting conditions such as the cutting speed, feedrates and the path interval on the surface integrity were evaluated by the analytical and the experimental approaches. Secondly, the cutting mechanism model was developed to predict the cutting force accurately. Prediction of cutting force make it possible to predict the shape error, estimate system stability and build the reliable adaptive control system. A large amount of experimental set are performed to show the validities of the proposed theories and to investigate the effect of cutting geometry such as rubbing effects, burr effects and etc.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1483-1488
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• 2017

In order to predict and control the environmental and health impacts of ionizing radiation in environmental sources such as groundwater, it is necessary to identify the radionuclides present. Beta-emitting radionuclides are frequently identified by measuring their characteristic energy spectra. The present work shows that self-attenuation effects from volume sources result in a geometry-dependent shift in the characteristic spectra, which needs to be taken into account in order to correctly identify the radionuclides present. These effects are shown to be compounded due to the subsequent shift in the photon spectra produced by the detector, in this case an inorganic solid scintillator ($CaF_2:Eu$) monitored using a silicon photomultiplier. Using tritiated water as an environmentally relevant, and notoriously difficult to monitor case study, analytical predictions for the shift in the energy spectra as a function of depth of source have been derived. These predictions have been validated using Geant4 simulations and experimental results measured using bespoke instrumentation.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.144.1-144.1
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• 2015

The triggered vacuum switch(TVS) is a one of the important component in consisiting high power control systems(HPCS). The operating condition is depended on material, geometry, operating power and so on. Our research is focused on the effects of thses basic properties and ptimized condition, because these are critical conditons in understanding the TVS operation. Our experiment is accomplished with a copper electrode and a tungsten trigger pin after being assembled into a vacuum chamber. The operating voltage in our system is more than dozens of kV at the 5kV trigger pulse. Our goal is up to 300kJ, therefore the currents should be more optimized in additional experiments,

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.187-189
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• 2004

This paper presents the system widely used for extraction of human body recognition system in the field of bio-metric identification. The Human body recognition system is used in many fields. This biological is appled to the human recognition in banking and the access control with security. The important algorithm of the identification software usese hand lines and hand shape geometry. We used the simple algorithm and recognizing the person by their hand image from the input camera. The geometrical characteristics in hand shape such as length of finger to whole hand length thickness of finger to length, etc are used.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1764-1769
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• 1991

Recently, dexterous mechanical hands have become of interest in the field of robotics. In this paper, a new symbolic C-Y notation is proposed for the kinematic modeling, and we solve the kinematics of a simplified model of POSTECH Hand 1, which is a 5 fingered, 20 degrees of freedom anthropomorphic hand. POSTECH Hand I is designed to have distinctive kinematic structure and the kinematic analysis of the hand is carried out using C-Y notation. To prove the feasibility of C-Y notation, D-H notation is also applied to the POSTECH Hand 1. In the inverse kinematic analysis, we neglect the fingertip geometry and assume the point contact with 3 degrees of freedom constraints. The configurations which optimize manipulability index[2] was obtained based on the simulation experiments on the SUN-4 graphic workstation using SUNPhigs graphic software.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.04a
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• pp.25-32
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• 1994

The pre-processor for finite to element structural analysis considering the user-friendly device is developed by using GUI. This can be used on WINDOWS' environment which is realized the multi-tasking and the concurrency by object-oriented paradigm. Data input can be done easily through menu, dialog box, automatic stepwise input and concurrent representation with the structural geometry on multiple windows. It in designed to control integratedly the pre-processing, execution and the post-processing of the finite element structural analysis program on multiple windows, and input data can be seen with result outputs at the same time. In addition, the object-oriented programming environment makes convenient revision and addition of the program components for expanding the scope of analysis and making better user environment.

• Korean Journal of Child Studies
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• v.16 no.1
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• pp.79-88
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• 1995

The purpose of this study was to investigate whether the experience of computer programming in Logo geometry advances the development of young children's concepts and/or representation of Euclidian spatial relations, particularly their concepts of the vertical-horizontal. Papert's claim of the positive effects of Logo programming experiences on young children's cognitive development was tested using the Piagetian Water Level Test (PWLT), the Free Hand Drawing Test (FHDT), and the Computer Drawing Test (CDT). Forty-four subjects were drawn from 2nd graders attending a public elementary school in Ithaca. The subjects were divided into 2 groups: a treatment group (TG) with Logo training for 10 weeks and a control group (CG) without Logo training. Our results showed that TG did not make any significant improvement on PWLT. In contrast, TG outperformed CG on FHDT. We suggested several possible explanations for this contradiction.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.156-159
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• 2001

Recently, side scan sonar system has been developed and operated to survey cable laying, sunken bodies, geometry of sea bottom and so on. It uses the acoustic signals, which are emitted from two transducer arrays, left and right sides, to get geometric information of the specified area. This system consists of transceiver board, towed body, deck unit and GPS receiver. The transceiver board, nested in a watertight canister, controls the transmitting and receiving of the acoustic pulses from transducer arrays. After receiving the scattered signals, it processes BP(Band Pass) filtering, AGC(Automatic Gain Control), TVG(Time Varying Gain) and Heterodyne. The deck init has the signal processing part, A/D converter, power supplier, and real-time monitoring part. The towed body has been designed to satisfy the optimal hydrodynamic behavior during towing, In this paper, brief introductions on the design theory of transceiving part and some results from the field which have been operated recently will be introduced.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.95-99
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• 2009

To avoid monotony of functionalistic architecture that may be considered the mainstream of modernism architecture, in recent days, the modern architecture displays diversified characteristics. Geometric manipulation method that creates an open space having manipulated a basic geometric shape like hexahedron (cutting out or joining the spatial area onto one side of the figure) is the space manipulation technique that has been introduced and emerged on a full scale since 1970. This technique has been developed as a type of living quarters that has equipped with passive control function, making outside climate flow into the interior. Recently methods for diversified space creation by means of geometry manipulation have begun to appear in domestic low rise multi-family housings other than inflexible box type high-rise building constructions, which comprise the mainstream of multi-family housing.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.248-253
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• 1997

The ideal surface roughness is obtained by tool geometry and feed rate in face milling. however actual surface roughness is affected by various factors such as cutting conditions. vibration and used tool. To improve the quality and productivity of the machining parts, lots of research on the evaluation of tool life and control of surface roughness has been required. Therefore, the width of flank wear, cutting force, and surface roughness are monitored to analyse the characteristics of surface roughness. This experimental investigation is mainly focused on the characteristics of surface roughness in multi-insert milling using TiN coated tool.