• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.77.4-77
• /
• 2001

The quality of agricultural products is classified with various factors which are measured and determined by destructive and/or nondestructive method. NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. CCD color camera is used to measure external quality like color and a size of fruit. today, nondestructive methods are widely researched. The quality and the garde of fruit loaded into a cup automatically and measured in real time by camera and NIR system is determined by internal and external factors. This paper proposes modified boundary tracking algorithm which detects the contour of fruit´s color image and make chain code faster than conventional method ...

• Nuclear Engineering and Technology
• /
• v.49 no.5
• /
• pp.920-927
• /
• 2017

With ever-advancing computer technology, the Monte Carlo (MC) neutron transport calculation is expanding its application area to nuclear reactor transient analysis. Dynamic MC (DMC) neutron tracking for transient analysis requires efficient algorithms for delayed neutron generation, neutron population control, and initial condition modeling. In this paper, a new MC steady-state simulation method based on time-dependent MC neutron tracking is proposed for steady-state initial condition modeling; during this process, prompt neutron sources and delayed neutron precursors for the DMC transient simulation can easily be sampled. The DMC method, including the proposed time-dependent DMC steady-state simulation method, has been implemented in McCARD and applied for two-dimensional core kinetics problems in the time-dependent neutron transport benchmark C5G7-TD. The McCARD DMC calculation results show good agreement with results of a deterministic transport analysis code, nTRACER.

• ETRI Journal
• /
• v.30 no.1
• /
• pp.158-160
• /
• 2008

A highly linear and efficient GaN HEMT Doherty amplifier for wideband code division multiple access (WCDMA) repeaters is presented. For better performance, the adaptive gate bias control of the peaking amplifier using the power tracking circuit and the shunt capacitors is employed. The measured one-carrier WCDMA results show an adjacent channel leakage ratio of -43.2 dBc at ${\pm}2.5$-MHz offset with a power added efficiency of 40.1% at an average output power of 37 dBm, which is a 7.5 dB back-off power from the saturated output power.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.193-200
• /
• 2007

There is an advantage that RFID system is better than previous bar code system in storage ability and noncontact property. But, everyone can easily receive the transmitting information by using RF signal. So, there is a problem that system security and personal privacy are threatened. In this paper, I propose RFID system that is secure against attacks like eavesdropping, replay, spoofing and location tracking and can efficiently provide mutual authentication services between reader and tag. The proposed RFID system can be used in various sections of ubiquitous computing environment.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.5
• /
• pp.1-13
• /
• 1995

In this paper, we evaluated the mean acquisition time and it's variance of the rapid synchronization system using the DMF(Digital Matched Filter) under the DS/CDMA system which uses the long period PN code. And we implemented the synchronization system that satisfies the specification demanded by the proposed EIA/TIA Interim Standard of Qualcomm Company. We showed that the state of the PN spreading code was estimated using the DMF(Digital Matched Filter) and then exact and fast chip synchronization could be achieved by the early-late tracking loop in the multiple channel environment. And we suggested the possibility that this synchronization system could be useful in the emerging digital cellular DS/CDMA system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.04a
• /
• pp.501-506
• /
• 2000

Many research in Robot control has effectively proceeded on the development of Aritficial Intelligence Robot which is able to apply to the uncertain and monotonous operations which are repeated continuously in the industrial field. In this study, the precise shape recognition of base metal for welding was gained by mono CCD camera, and the gained data was transformed into Decimal code through Image Board in computer. And the Fuzzy Logic control system designed by use of Fuzzy rule was built to judge whether the base metals were precisely matched or not with Decimal code. Machanically manipulated Robot syst em was linked to Fuzzy Control system through image information, and ultimately, these systems will be able to apply for production system.

• Journal of The Korean Astronomical Society
• /
• v.34 no.4
• /
• pp.293-295
• /
• 2001

A numerical scheme that incorporates a self-consistent cosmic-ray (CR, hereafter) injection model into the combined gas dynamics and CR diffusion-convection code has been developed. The hydro/CR code can follow in a very cos-effective way the evolution of CR modified shocks by adopting subzone shock-tracking and multi-level Adaptive Mesh Refinement techniques. The injection model is based on interactions of the suprathermal particles with self-generated MHD waves in quasi-parallel shocks. The particle injection is followed numerically by filtering the diffusive flux of suprathermal particles across the shock to upstream region according to a velocity-dependent transparency function, which represents the fraction of leaking suprathermal particles. In the strong shock limit of Mach numbers $\ge$20, significant physical processes such as the injection and acceleration seem to become independent of M, while they are sensitively dependent on M for M < 10. Although some particles injected early in the evolution continue to be accelerated to higher energies, the postshock CR pressure reaches a time asymptotic value due to balance between acceleration and diffusion of the CR particles.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.10 s.253
• /
• pp.1235-1241
• /
• 2006

A new hydrocode which is still under development using Lagrangian, Eulerian and arbitrary Lagrangian-Eulerian operators, has been described. The three operators are implemented into a single framework by incorporating the sequential three stages of Lagrangian, remesh and remap stages. Several numerical schemes used for each operator are discussed briefly in this paper. In order to evaluate the characteristics of each operator, the Taylor Impact Test has been simulated using each operator and the results are compared. Currently the code is 1st order accuracy in the material interface tracking algorithm and can not handle multimaterial in the mixed cell. The areas of possible enhancement of the code are also discussed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.342-349
• /
• 2012

We study the gap effect on detonating high explosives using the characteristic acoustic impedance theory and numerical simulation. A block of charge embedded with multiple gap inserts is detonated at one end to understand the ensuing flame propagation through multiple gap materials. The present high-order multimaterial simulation provides meaningful validation of complex interface tracking algorithm as it is implemented in the SNU-Hydropack code.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2501-2503
• /
• 2005

탐침형 정보 저장 장치는 원자 현미경의 원리를 이용한 차세대 고밀도 저장장치로 여겨진다. 정보의 크기가 수십 나노미터 이하이므로 정밀한 위치 제어 알고리즘이 필수적이다. 본 논문에서는 별도의 위치 센서없이 복수개인 탐침을 이용하여 원하는 데이터 위치로 이동하는 servo algorithm, 정보 추종을 위한 tracking algorithm 및 위치 검출용 탐침의 수를 줄이고 최적 제어기 설계를 위한 노이즈 특성 안정화를 위한 servo code 설계법을 제안하고 제어기 설계법을 제안한다.