• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1191-1197
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• 2003

In the multi-carrier OFDM communication system, the inter-carrier-interference(ICI) produced by phase noise in the transceiver local oscillator makes a severe influence on the system performance. In this paper, a new ICI self-cancellation scheme in the data-conversion type is proposed to reduce effectively the ICI. Also, the common phase error(CPE), ICI and carrier to interference power ratio(CIR) are found by the linear approximation of the phase noise. Then, the proposed method is compared with the conventional OFDM to analyze the efficiency of system performance improvement. When the number of subcarriers is 64, there are respectively the SNR gain of 0.6 ㏈ in the phase noise variance of 0.3 with QPSK and 1.5 ㏈ in the phase noise variance of 0.1 with 16 QAM at BER=10$\^$-3/. As a result, the performance degradation by ICI can be effectively lowered in the proposed system with ICI self. cancellation scheme, compared with the conventional OFDM system.

• Journal of Information Processing Systems
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• v.16 no.1
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• pp.120-131
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• 2020

In order to solve the problem of point clouds coordinate conversion of non-directional scanners, this paper proposes a basic Rodrigues rotation method. Specifically, we convert the 6 degree-of-freedom (6-DOF) rotation and translation matrix into the uniaxial rotation matrix, and establish the equation of objective vector conversion based on the basic Rodrigues rotation scheme. We demonstrate the applicability of the new method by using a bar-shaped emboss point clouds as experimental input, the three-axis error and three-term error as validate indicators. The results suggest that the new method does not need linearization and is suitable for optional rotation angle. Meanwhile, the new method achieves the seamless splicing of point clouds. Furthermore, the coordinate conversion scheme proposed in this paper performs superiority by comparing with the iterative closest point (ICP) conversion method. Therefore, the basic Rodrigues rotation method is not only regarded as a suitable tool to achieve the conversion of point clouds, but also provides certain reference and guidance for similar projects.

• Journal of Power Electronics
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• v.9 no.2
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• pp.300-307
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• 2009

In this paper, design and control is proposed for a four input-series-output-series-connected ZVS full bridge converter for the photovoltaic power conditioning system (PCS). The novel topology for a photovoltaic (PV) DC/DC converter that can dramatically reduce the power rating and increase the efficiency of a PV system by analyzing PV module characteristics is proposed. The control scheme, including an input voltage controller is proposed to achieve equal sharing of the input voltage as well output voltages by a four series connected module. Design methods for ZVS power stage are also introduced. The total PV system is implemented for a 250-kW PV power conditioning system (PCS). This system has only three DC/DC converters with a 25-kW power rating and uses only one-third of the total PV PCS power. The 25-kW prototype PV DC/DC converter is introduced to verify experimentally the proposed topology. In addition, an experimental result shows that the proposed topology exhibits good performance.

• Quality Improvement in Health Care
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• v.3 no.2
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• pp.52-59
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• 1997

Background : In many Nursing Delivery System, Nursing Department at D Hospital had used to traditional nursing practice model what is called functional activities based system. It has a lot of merit that carried out specialized and rapid works but tend to ignore indivisual professional responsibility and task-based work assignments. In addition this system showed high turnover rates due to heavy workload, timesum of handing over duties, lack of support from peers and interstaff communication. So we performed conversion of Nursing Delivery System to My Patients Nursing Care System for providing comprehensive nursing to patient and reducing turnover rates and increasing job satisfaction to nurse. Method : 1. 1st step(96.4.9): Detected the problem of Nursing delivery System and estabilished improving planning 2. 2nd step(96.4.26): Visited other hospital on job training 3. 3th step(96.4.29): Discussed to premonitoring problem after conversion Nursing Delivery System and prepared structure 4. 4th step(96.5.6): My Patients Nursing Care System practical application 5. 5th step(96.7.20): Held complementary meeting 6. 6th step(96. 7): The other ward application 7. 7th step(96. 10): Extended application to whole wards Results: 1. Workload: (1) reduction(55.6%) (2) addition(44.4%) 2. Strong points after conversion: (1) decreased timesum of handing overduties (35.2%) (2) increased responsibility(33%) (3) broaden nurse's outlook to duties(14.8%) 3. Shortcoming after conversion: (1) understanding difficulties except my patient(57.8%) (2) weak teamwork(23.3%) (3) intensive stress to low grade nurse(12.2%) 4. Effective complemental way: (1) manpower(76.7%) (2) conversion of though (8.9%) (3) education(14.4%) 5. Patient's satisfaction: (1) satisfaction(64%) (2) no effect(36%) 6. Physician and peer's satisfaction: (1) satisfaction(12.5%) (2) dissatisfaction(21.6%) (3) no interest(44.3%) 7. Nurse's satisfaction: (1) satisfaction(74.7%) (2) dissatisfaction(5.5%) (3) unknown(20.5%) 8. Want to continued: (1) want(76.4%) (2) try to any other system(18%) Conclusion : Even though Nursing Delivery System conversion still has many problem, we gained more merits than traditional nursing delivery system. So we suggest that My Patients Nursing Care System should be encouraged for comprehensive nursing care and satisfaction to nurses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1151-1156
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• 2007

In this paper, we develop a new conversion method for implementing binary ECG(Electrocardiogram) conversion scheme to improve our previous research works that supported the conversion of binary ECG files into HL7 aECG for enhancing interoperability of ECG data. HL7 aECG is a XML-based standard for interoperability of ECG waveform. To improve the performance of ECG data conversion, we utilize a compilation-based ECG conversion method on binary ECG files. Our new method supports both flexibility of BED-based ECG conversion mechanism and the performance of direct conversion mechanism.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.35-42
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• 2003

We have studied DC energy conversion of RF card by wireless communication. In order to attain an objective, it used the system which is a Rectenna. The main purpose of energy conversion system is the operation of the circuits at RF-ID system. The proposed RF-ID system is a lot classified with the reader and tag. Reader is a kind of the base station role supporting RF energy. And priority tag convert RF energy from the reader it was delivered with a wireless to DC energy. The energy which is converted like Tag. It transmits to the reader characteristic ID of each card. The tag is mainly divided into rectifier, power module, memory and controller. The FRAM maintains the data like a ROM in no-power situation. And the advantage is a low power element compared with other EEPROM. There are two considerations, when RF energy is converted into DC source by wireless. One is energy amount supported from the reader, the other is high power efficiency. This paper presents a study of simulation and experiments on the RF-DC conversion circuit in tag by the power efficiency concentrated.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.20-26
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• 2009

In this paper, the switching mode conversion type pulse charger by fly-back converter method for lead battery of the solar cell generator equipment is proposed. And we propose the control circuit and design method of insulated switching mode convert type pulse charger by fly-back convert method in the lead battery. The proposed system can minimize the current consumption by digital pulse. Also the proposed system can generate the constant 10[KHz] frequency, transmit the signal with main control system in the power control system. And it supervises the state of lead battery using one chip micro processor. The proposed the switching mode conversion type pulse charger by the fly-back converter method can charge fast and stabilize lead battery with nominal value 12[V], 20[AH]. Also we propose the design procedure of the power control circuit for turn ratio of fly-back inductor and determining method of values such as the charging current, bulk current, partial current, over current value and fixed charging voltage. The experiment results for the voltage and current wave for partial, bulk, over and fixed charging period show the good charging effect and performance. And the PCB and internal coupling diagram of the switching mode conversion type pulse charger by fly-back converter method is presented.

• Journal of Power Electronics
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• v.11 no.4
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• pp.464-470
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• 2011

In this paper, the feasibility of applying a position sensorless control technique to hybrid electric vehicles (HEVs) is practically evaluated. The proposed position estimator has a straightforward structure with properties that combines the model and the saliency tracking-based rotor position estimation for interior permanent magnet synchronous motors (IPMSMs). The proposed method can be used in the event of sensor loss or sensor recovery to sustain continuity of operations. The developed system takes into account the estimated position transition between two distinct sensorless methods. The transition is enhanced by introducing a synchronized transition algorithm based on a single tracking observer. Extensive experimental results are presented to verify the principles and show a reliable estimation performance over the entire speed range including standstill under 150% load conditions.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3181-3188
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• 2008

The supercritical $CO_2$ Brayton cycle energy conversion system is presented as a promising alternative to the present Rankine cycle. The principal advantage of the S-$CO_2$ gas is a good efficiency at a modest temperature and a compact size of its components. The S-$CO_2$ Brayton cycle coupled to a SFR also excludes the possibilities of a SWR (Sodium-Water Reaction) which is a major safety-related event, so that the safety of a SFR can be improved. KAERI is conducting a feasibility study for the supercritical carbon dioxide (S-$CO_2$) Brayton cycle power conversion system coupled to KALIMER(Korea Advanced LIquid MEtal Reactor). The purpose of this research is to develop S-$CO_2$ Brayton cycle energy conversion systems and evaluate their performance when they are coupled to advanced nuclear reactor concepts of the type under investigation in the Generation IV Nuclear Energy Systems. This paper contains the research overview of the S-$CO_2$ Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.8-17
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• 2015

This paper presents a sound into color signal conversion using a colored-hearing synesthesia. The aim of the present paper is to implement a real-time conversion system which focuses on both hearing and sight which account for a great part of bodily senses. The proposed method of the real-time conversion of color into sound, in this paper, was simple and intuitive where scale, octave and velocity were extracted from MIDI input signals, which were converted into hue, intensity and saturation, respectively, as basic elements of HSI color model. In experiments, we implemented both the hardware system for delivering MIDI signals to PC and the VC++ based software system for monitoring both input and output signals, so we made certain that the conversion was correctly performed by the proposed method.