• International conference on construction engineering and project management
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• 2011.02a
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• pp.480-486
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• 2011

Conservation of energy and fuel is the trend in smart building design. Radio Frequency Integrated Circuit (RFIC) technology is often used in temperature sensing and signal transmission to manage indoor temperature, but it is rarely applied to the shell of the building. Heat retention and poor insulation in building shells are the largest causes of high energy consumption by indoor air conditioning. Through combining RFIC technology with temperature sensors, this study will develop smart temperature information material that can be embedded in concrete. In addition to accurately evaluating the effectiveness of shell insulation material, the already-designed Building Physiology Information System can monitor long-term temperature changes, leading to smarter building health management.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.6-14
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• 2007

The purpose of urodynamic investigation is to determine information on the function of the urinary system. One of the most frequently used measurement procedures in urodynamics is filling and voiding cystometry using invasive method. But in this method transurethral catheter is use and it makes patients uncomfortable. The aim of this study was to implement the system that could evaluate the function of urinary tract with noninvasive and comfortable method. Therefor in this study, a sensor and measuring system were implemented to measure uroflow, urophonography and noninvasive bladder pressure signal during urination for diagnosing the LUTS(lower urinary tract symptoms) using noninvasive method. The implemented system compose of the sensor parts, signal conditioning parts, system control parts using FPGA and PC monitoring program. For the evaluation of the implemented system, the simulation of system's control part was performed and the model system for the lower urinary system was designed. From the evaluation of the model system, the mean error rate of the uroflow measurement part was 1.08% and coefficient of variation was 1,48. And the mean error rate of the noninvasive bladder pressure measurement part was 2.41% and coefficient of variation was 2.81. urophongraphy signal analysis was accomplished in a time domain and frequency domain. Average RMS power was used in a time domain analysis, and MF was used in a frequency domain analysis. From the evaluation of the model system average RMS power and MF was dependent on the occlusion degree significantly and median frequency range of $60{\sim}160Hz$ was correlated with the occlusion.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.325-330
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• 2012

A single-phase PVPCS(photovoltaic power conditioning system) that contains a single phase dc-ac inverter tends to draw an ac ripple current at twice the out frequency. Such a ripple current may shorten passive elements life span and worsen output current THD. As a result, it may reduce the efficiency of the whole PVPCS system. In this paper, the ripple current propagation is analyzed, and two methods to reduce the ripple current are proposed. Firslyt, this paper presents notch filter with IP voltage controller to reject specific current ripple in single-phase PVPCS. The notch filter can be designed that suppress just only specific frequency component and no phase delay. The proposed notch filter can suppress output command signal in the ripple bandwidth for reducing output current THD. Secondly, for reducing specific current ripple, the other method is feed-forward compensation to incorporate a current control loop in the dc-dc converter. The proposed notch filter and feed-forward compensation method have been verified with computer simulation and simulation results obtained demonstrate the validity of the proposed control scheme.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.1
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• pp.11-18
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• 2006

Man has always striven to create a thermally comfortable environment. This is reflected in building traditions around the world - from ancient history to present day. Today, creating a thermally comfortable environment is still one of the most important parameters to be considered when designing buildings. It is defined in the ISO 7730 standard as being "That condition of mind which expresses satisfaction with the thermal environment". A definition most people can agree on, but also a definition is not easily converted into physical parameters. Thermal comfort is a matter of many physical parameters, and not just one, as for example the air temperature that is set by air-conditioner. The most important matter Today's common offices and homes are only depending on air-conditioning as a cooling system during the summer. This kind of system tends to be focused on the person who controls it and those who are around the air-conditioner while thermal-comfort is neglected. Futhermore, the people's body conditions are not considered during each time that beginning, middle, last of the air-conditioning which causing displeasure of the residents more and more. This kind of operating system is set for a long time may causes unbalanced air condition and man's psychologic displeasure goes to increase.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.3
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• pp.283-292
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• 2011

This paper proposed a new multi-level inverter topology based on a H-bridge with two switches and two diodes connected to the DC-link. The output voltage of the proposed topology is quite closer to a sinusoidal waveform compared with a typical single phase inverter. The proposed multi-level inverter is applicable to a power conditioning system for renewable energy sources, and it can be also used as a building block of a cascaded multi-level inverter for a high voltage application. In case of conventional H-bridge type or NPC type multi-level inverter, 8 controllable switches are used to obtain a 5 level output voltage, but the proposed multi-level inverter requires only 6 controllable switches. Thus the circuit configuration is quite simple, reliable and cost-effective implementation is possible. The efficiency can be improved owing to the reduction of the switching loss. A new PWM method based on POD modulation is suggested which requires only one carrier signal. The switching sequence to make the capacitor voltage balanced is also considered. The feasibility is studied through simulation and experiment.

• Journal of Biosystems Engineering
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• v.33 no.5
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• pp.317-325
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• 2008

The electrocardiogram (ECG) measurement system consists of I/O interface to input the ECG signals from two electrodes, FPGA (Field programmable gate arrays) module to process the signal conditioning, and real time module to control the system. The algorithms based on wavelet transform were developed to remove the noise of the ECG signals and to determine the QRS-waves. Triangular wave tests were conducted to determine the optimal factors of the wavelet filter by analyzing the SNRs (signal to noise ratios) and RMSEs (root mean square errors). The hybrid rule, soft method, and symlets of order 5 were selected as thresholding rule, thresholding method, and mother wavelet, respectively. The developed wavelet filter showed good performance to remove the noise of the triangular waves with 10.98 dB of SNR and 0.140 mV of RMSE. The ECG signals from a total of 6 subjects were measured at different measuring postures such as lying, sitting, and standing. The durations of QRS-waves, the amplitudes of R-waves, the intervals of RR-waves were analyzed by using the finite impulse response (FIR) filter and the developed wavelet filter. The wavelet filter showed good performance to determine the features of QRS-waves, but the FIR filter had some problems to detect the peaks of Q and S waves. The measuring postures affected accuracy and precision of the ECG signals. The noises of the ECG signals were increased due to the movement of the subject during measurement. The results showed that the wavelet filter was a useful tool to remove the noise of the ECG signals and to determine the features of the QRS-waves.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.818-819
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• 2015

PAL-XFEL 장치에 사용 할 고전압 펄스 모듈레이터 출력파워는 수 ${\mu}s$ 범위의 짧은 고전압(400 kV), 대전류(500 A) 펄스를 요구한다. 이러한 펄스파워를 얻기 위해서 PFN(Pulse Forming Network)에 에너지를 축적하고, 플라즈마 스위치인 싸이라트론을 통하여 에너지를 신속하게 클라이스트론 쪽으로 전달한다. 클라이스트론은 모듈레이터에서 공급하는 펄스 전원을 이용하여 RF를 증폭하는 대출력 고주파 증폭장치이다. 고전압 펄스 모듈레이터 제어기는 고속펄스 신호처리 모듈(Fast Pulse Signal Conditioning Module), PLC(Programmable Logic Controller)로 구성되어 있다. 고전압 펄스 모듈레이터에 사용하는 대용량 싸이라트론은 고전력을 스위칭 할 때 발생하는 스위칭 노이즈는 매우 크다. 이러한 노이즈는 모듈레이터의 출력 시그널인 빔 전압, 빔 전류, EOLC(End of Line Clipper) 전류, DC high voltage에 섞여 있으면서 신호 왜곡 및 제어장치의 고장을 유발시킨다. 이처럼 노이즈가 많이 포함되어 있는 아닐로그 신호를 깨끗한 신호(a clean signal)로 바꾸어주는 노이즈 필터링 장치인 고속펄스 신호처리 모듈을 제작하여 실험한 결과를 알아보고 모듈레이터 인터록 시스템인 PLC에서 Dynamic Interlock의 응답시간을 빠르게 하기위한 회로 수정에 대한 결과에 관하여 기술하고자 한다.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.116-121
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• 2021

A lot of research is being done to develop a high-efficiency heat pump to save energy, and research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil is also being conducted at the same time. A curved constant temperature chamber was constructed that can be tested under the same conditions as in the natural state so that the research can be conducted in which frost does not occur on the outdoor unit of the heat pump regardless of the season. Simulations were performed to verity whether such a curved constant temperature chamber has feasibility as an experimental device. For CFD conditions, the length of the straight duct in front of the outdoor unit located in the duct-type constant temperature chamber was 1, 5, 10 and 15 times the diameter of the duct. As a result, it was found that a straight space must be secured 10 times the diameter of the duct.

• Korean Journal of Biological Psychiatry
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• v.19 no.4
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• pp.164-171
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• 2012

The placebo effect, a response observed during the placebo arm of a clinical trial, is produced by the psychobiological action of the placebo as well as by other potential contributors to symptom amelioration such as spontaneous improvement, regression to the mean, biases, concurrent treatments, and study design. From a psychological viewpoint, there are many mechanisms that contribute to placebo effects, including expectations, conditioning, learning, and anxiety reduction. Placebo responses are also mediated by opioid and non-opioid mechanisms including dopamine, serotonin, cholecystokinin, and immune mediators. During recent years, a trend towards increased placebo effects in clinical trials of neuropsychiatric drugs has been noted. Indeed, the placebo effects observed in clinical trials constitute an increasing problem and interfere with signal-detection analyses of potential treatments. Several potential factors including protocol/study design and conduct related factors may account for the placebo effect observed in clinical trials. This paper reviews key issues related to this problem and aims to identify potential solutions.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.9
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• pp.77-86
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• 1998

A two-chip humidity sensor system has been developed which consists of a capacitive sense element die and a CMOS interface chip. The sense element was fabricated using thin polyimide films on (100) silicon substrate and showed excellent linearity(0.72%FS), low hysteresis (<3%) and low temperature coefficient(-0.0285 ~-0.0542pF/K) over a wide range of relative humidity and temperature. The capacitance-relative humidity characteristic exhibited a drift of 2~3% after 9 weeks of exposure to 4$0^{\circ}C$/90%RH. The signal-conditioning circuitry was fabricated using an 1.2- ${\mu}{\textrm}{m}$, one poly double metal CMOS process. The measured output voltage of the sensor system was directly proportional to relative humidity and showed good agreement with theory.