• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.8
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• pp.670-677
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• 2017

In this paper, we propose a rotational motion compensation(RMC) for bistatic inverse synthetic aperture radar(Bi-ISAR) imaging. For this purpose, geometry-error, caused by changes of bistatic-angle, is removed using known position information of a transmitter, a receiver, and target trajectories. Next, RMC is performed to compensate non-uniform rotational motion error by reformatting radar signal in terms of a newly defined slow time variable that converts non-uniform rotational motion into uniform one. Simulation results using an aircraft model composed of ideal point scatterers validate the efficacy of the proposed Bi-ISAR RMC method.

• The Journal of Advanced Prosthodontics
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• v.11 no.4
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• pp.223-231
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• 2019

PURPOSE. The purpose of this study was to evaluate the shear bond strength (SBS) of an indirect resin composite (IRC) to the various resin matrix ceramic (RMC) blocks using different surface treatments. MATERIALS AND METHODS. Ninety-nine cubic RMC specimens consisting of a resin nanoceramic (RNC), a polymer-infiltrated hybrid ceramic (PIHC), and a flexible hybrid ceramic (FHC) were divided randomly into three surface treatment subgroups (n = 11). In the experimental groups, untreated (Cnt), tribochemical silica coating (Tbc), and Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser irradiation (Lsr) with 3 W (150 mJ/pulse, 20 Hz for 20 sec.) were used as surface treatments. An indirect composite resin (IRC) was layered with a disc-shape mold ($2{\times}3mm$) onto the treated-ceramic surfaces and the specimens submitted to thermal cycling (6000 cycles, $5-55^{\circ}C$). The SBS test of specimens was performed using a universal testing machine and the specimens were examined with a scanning electron microscope to determine the failure mode. Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tukey HSD test (${\alpha}=.05$). RESULTS. According to the two-way ANOVA, only the surface treatment parameter was statistically significant (P<.05) on the SBS of IRC to RMC. The SBS values of Lsr-applied RMC groups were significantly higher than Cnt groups for each RMC material, (P<.05). Significant differences were also determined between Tbc surface treatment applied and untreated (Cnt) PIHC materials (P=.039). CONCLUSION. For promoting a reliable bond strength during characterization of RMC with IRC, Nd:YAG laser or Tbc surface treatment technique should be used, putting in consideration the microstructure and composition of RMC materials and appropriate parameters for each material.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.177-180
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• 2002

This study is performed to properties of ready mixed concrete (RMC) in site. The unit weight of the B company's RMC is range from $2,308kg/m^3\;to\;2,355kg/m^3$ and that of the J company's RMC is range from $2,288kg/m^3\;to\;2,310kg/m^3$. The compressive strength of B company's RMC of curing age of 7 days is range from $191kgf/cm^2-232kgf/cm^2$ and that of curing age of 28days is $273kgf/cm^2{\sim}306kg/cm^2$. The compressive strength of J company's RMC of curing age of 7 days is range from $151kgf/cm^2{\sim}177kgf/cm^2$ and that curing age of 28 days is range from $215kgf/cm^2{\sim}234kgf/cm^2$. The B and J company's air content is range of $3.2{\sim}5.2%$. The content of Chloride of the Band J company's is range from each $0.026kg/m^3{\sim}0.046kg/m^3\;and\; 0.034kg/m^3{\sim}0.069kg/m^3$, respectively.

• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.63-69
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• 2012

Ready-mixed concrete(RMC) has been a major construction materials for infrastructures. However, RMC with poor quality is reported to be social issue since it directly user's safety and convenience. Because the properties of concrete as a construction material are greatly influenced by the variation of water content, to control water accurately is the most efficient method for the quality control in RMC industry. In this study, the automatic measurement technology of fine aggregate was developed by using the microwave moisture measurement. For the various conditions of fine aggregate such as moisture, temperature and pressure, the calibration curve of moisture measurement was obtained by using oven-dry method. From the infield and outfield test, it can be obtained that the accuracy of microwave moisture measurement is very high and the automatic system of microwave moisture measurement is very convenient and useful for quality control in RMC Industry.

• Journal of the Korea Institute of Building Construction
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• v.11 no.5
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• pp.468-481
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• 2011

This research presents a strategy and information system to manage the logistics of delivery ready mixed concrete (RMC) under the integrated environment of PMIS+RFID. PMIS is system tool and technique used in construction sectors to delivery information. Information that can be extracted electronically in real time is more valuable than data gathered and maintained manually. RFID technology can help to improve data accuracy through supply chains and by identifying products and objects at specific points through automatic identification. The objectives of these two implementations can be able to improve the efficiency of logistics management for RMC truck process, and to verify the technical and practical feasibility of PMIS+RFID application in construction industry. This may be realistic given the dynamics of daily activities on construction sites. This research is focused on examples on real world case study, applications and research theme related and connected to PMIS+RFID technology. It demonstrated that PMIS+RFID technology has been automatically implemented and has shown process information about the RMC truck and the overall status information about it, both quickly and accurately. As a result, the construction site where needs 300 $m^3$ pouring (50 RMC trucks) per day can be reduced total 250 minutes. Moreover, this time saving is related to the labour cost saving. From the case studies, RFID+PMIS system was proven in terms of effectiveness rather than current method.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.821-826
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• 2006

This paper describes a rollover index (RI)-based rollover mitigation control (RMC) system. A rollover index which indicates an impending rollover has been developed by a roll dynamics phase plane analysis. The rollover index is calculated using the roll angle, the roll rate, the lateral acceleration and time to wheel lift (TTWL). A differential braking control law based on a 2-D bicycle model has been designed using the direct yaw control (DYC) method. An RMC threshold has been determined from the rollover index. The performance of the RMC scheme and the effectiveness of the proposed rollover index are illustrated using a vehicle simulator.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2297-2306
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• 2015

This paper presents the development of a system with a reverse matrix converter (RMC) for permanent magnet synchronous motor (PMSM) drive and its effective control method. The voltage transfer ratio of the general matrix converter is restricted to a maximum value of 0.866, which is not suitable for applications whose source voltages are lower than the load voltages. The proposed RMC topology can step up the voltage without any additional components in the conventional circuit. Its control method is different from traditional matrix converter’s one, thus this paper proposes control schemes of RMC by means of controlling both the generator and motor side currents with properly designed control loop. The converter can have sinusoidal input/output current waveforms in steady state condition as well as a boosted voltage. In this paper, a hardware system with an RMC for a PMSM drive system is described. The performance of the system was investigated through experiments

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3544-3555
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• 2000

매칭방법은 기하 및 입체 모델링에서 재단 곡면과 이들에 대한 부울 연산에 사용되는 기초적인 연산이다. 그러나 매칭연산은 부드러움을 정확하게 표현하는데 고 차수의 미분계수 제약조건으로 인하여 많은 계산량이 필요할 뿐만 아니라 곡면상의 여러 점을 동시에 선택하여 이동하였을 때, 곡면표현에 사용되는 복잡한 함수식으로 인하여 일반해를 구하기 어려운 단점을 가진다. 본 논문은 분수식에 의하여 RMC(Rotation-Minimizing Curve)을 정의하고 이를 이용하여 자유 형태 곡면간에 변형 매칭 방법을 제안한다. RMC는 매칭곡선과 곡면의 접선벡터, 회전벡터, 곡률의 변화율과 같은 기하학적 기법을 기반으로 한다. 제안한 방법은 입력으로 주어지는 곡면의 기하학적 복잡도와는 무관하게 매칭을 수행할 수 있으며 수행 성능은 계산된 매칭 곡선의 복잡도에 의해서만 좌우된다. 또한 곡선 표현에 사용된 값들을 정의된 매칭 곡선식에 그대로 적용할 수 있었으므로 최적화 응용 문제에 효율적으로 적용할 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.387-392
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• 1992

This paper presents a local trajectory generation method which is based on a sequence of reference posture-velocities and the efficient low level control algorithm which constructs the complete smooth curve from the trajectory specification. The reference trajectory generator(RTG) which is in between the local path planner(LPP) and the robot motion controller(RMC) generates a sequence of set-points for each path segments from the LPP and pass it to the RMC. The RMC controls the motions of vehicle which should follow the sequence. In the feedback controller of VMC, the method which compensates robot posture-velocity error correctly is used. These methods are implemented on indoor autonomous vehicle, 'ALIVE' mobile robot. The ALIVE mobile robot system is implemented on the 32bit VME bus system: the two VME CPU's are used for RTG and RMC, while the 80C196KC-based VME board is used for motor controller.

• Progress in Superconductivity and Cryogenics
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• v.14 no.4
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• pp.36-40
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• 2012

This paper presents an experimental and numerical study on current limiting characteristics of a fault current controller (FCC). The FCC consists of an AC/DC power converter, a superconducting coil, and a control unit. Even though some previous researches proved that the FCC could adjust the fault current level, the current limiting characteristics by the superconducting coil should be investigated for design of the coil. In this paper, four kinds of model coils were tested; 1) air core, 2) iron core without any bias, 3) reversely magnetized core (RMC) using permanent magnets, and 4) RMC using an electromagnet. Based on a comparative study, it is confirmed that a RMC by an electromagnet (EM) could increase the effective inductance of the coil. In this paper, a numerical code to simulate the HTS coil with RMC was developed. This code can be applied to design the HTS coil with active reversely magnetized bias coil.