• 한국전자파학회논문지
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• 제14권11호
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• pp.1191-1197
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• 2003

무선 통신 시스템에서 고속 데이터 전송에 효율적인 다중 반송파 시스템인 OFDM통신 시스템에서는 송수신단의 오실레이터에서 발생하는 위상잡음이 인접채널간 간섭(Inter-carrier-interference: ICI)을 야기시켜 통신 성능에 악영향을 끼친다. 본 논문에서는 ICI영향을 효과적으로 줄일 수 있는 새로운 data-conversion 형식의 ICI 제거 방법을 제안하고 위상잡음을 선형 근사화하여 위상잡음에 의해 발생하는 common phase error(CPE), ICI 그리고 carrier to interference power ratio(CIR)를 분석한다. 그리고 data-conversion 형식의 위상잡음에 의한 성능 개선 효과를 분석하기 위해서 기존의 OFDM과 비교하였다. 이때 부반송파수 64의 조건하에서 위상 잡음 분산 0.3의 QPSK변조방식과 위상 잡음 분산 0.1의 16 QAM변조방식의 경우, BER=$10^{-3}$에서 각각 0.6 ㏈, 1.5 ㏈의 SNR 이득을 가짐을 볼 수 있다. 결과적으로 ICI 제거방법을 사용하였을 때 기존의 OFDM system에 비하여 ICI에 의한 성능손실을 효과적으로 줄일 수 있다.

• Journal of Information Processing Systems
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• 제16권1호
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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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• 제9권2호
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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.

• 한국의료질향상학회지
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• 제3권2호
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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.

• 전기학회논문지
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• 제56권6호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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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.

• 전기학회논문지P
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• 제58권1호
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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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• 제11권4호
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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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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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.

• 한국콘텐츠학회논문지
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• 제15권12호
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• pp.8-17
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• 2015

본 논문은 공감각의 한 부분인 색청(colored-hearing) 공감각을 이용한 사운드-컬러 신호 변환에 관한 연구로서, 인간이 인지 할 수 있는 오감 중 공감각적 변환이 가장 많이 일어나는 청각과 시각을 이용한 실시간 변환 시스템의 구축을 목표로 한다. 본 논문에서 제안하는 음-색 실시간 변환 방법으로서, 입력으로 사용하는 MIDI(Musical Instrument Digital Interface) 신호에서 음계(scale), 옥타브(octave) 및 음의 세기(velocity)를 추출한 후 HSI 컬러모델의 기본 요소인 색상(hue), 명도(intensity) 및 채도(saturation)에 각각 대응하여 변환하는 방법으로 단순하지만 직관적인 방법을 사용한다. 변환된 HSI 컬러 모델은 모니터 출력을 위해 RGB 컬러 모델로 최종 변환하여 출력한다. 실험에서, MIDI 입력신호 전송 H/W 시스템과 VC++ 기반 해당 사운드-컬러 변환 입 출력 S/W 모니터링 시스템을 구축하여 사운드에서 컬러로의 출력이 제안한 방식에 따라 값이 출력됨을 확인하였다.