• 한국소음진동공학회논문집
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• 제21권5호
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• pp.400-407
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• 2011

The suggested method of previous Son's study dichotomized subjective response data to modeling noise exposure-response. The method used maximum liklihood estimation instead of least square estimation and the noise exposure-response curve of the study was logistic regression analysis result. The method was originated to modeling community response rate such as %HA or %A. It can be useful when the subjective response was investigated based on predicted noise level. It is difficult to measure the single source emitting noise such as railway because various traffic noise sources combined in our life. The suggested method was adopted to model in this study and railway noise-exposure response curves were modeled because the noise level of this area was predicted data. The data of this study was used by previous Ko's paper but he dealt the area as combined noise area and divided the data by dominant noise source. But this study used all data of this area because the annoyance response to railway noise was higher than other noise according to the result of correlation analysis. The trend of the %HA and %A prediction model to train noise of this study is almost same as the model based on measured noise of previous Lim's study although the investigated areas and methods were different.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.207-207
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• 2011

Aromatic nitriles possess versatile utilities and are indispensible not only in organic synthesis but also in chemical industry. In fact, the nitrile group is an important precursor for various functional groups such as aldehydes, amines, amidines, tetrazoles, amides, and their carboxyl derivatives. Representative methods for the preparation of organonitriles with cyanide-containing reagents are the Sandmeyer and Rosenmund-von Braun reactions. Recently, a catalytic route to aryl nitriles has been reported on the basis of the chelation-assisted C-H bond activation or metal-catalyzed cyanation of haloarenes. In those cyanation protocols, the "CN" unit is provided from metal-bound precursors of MCN (M=Cu, K, Na, Zn), TMSCN, or K3Fe(CN)6. Additionally, it can be generated in situ from nitromethane or acetone cyanohydrin. Herein, we report the first example of generating "CN" from two different, readily available precursors, ammonia and N,N-dimethylformamide (DMF). In addition, its synthetic utility is demonstrated through the Pd-catalyzed cyanation of arene C-H bonds.

• 한국대기환경학회지
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• 제16권6호
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• pp.585-594
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• 2000

Through an application of Micrometerorological methods, we conducted measurements of Hg fluxes from Nan-Ji-Do which is well known as one of the major local areal sources in Seoul metropolitan area during Match/April of 2000. In the course of our study, we determined the concentration gradients of total gaseous Hg(between 20 and 2000 cm heights) and combined these data with Micrometerorological components to derive is fluxes. It turned out that emission from and dry deposition to soil surfaces occurred at the ratio of 72:27 from a total of 271 hourly measurements. The validity of measured concentration gradients( or resulting fluxes) was evaluated in terms of percent gradient. Accordingly, about more than 95% of gradient data derived were statistically significant. The mean fluxes of Hg across soil-air interface, when computed using the concentrations gradients and relevant parameters, were found at 253(during emission) and -846ng/$m^2$/h(during dry deposition) The occurrences of abnormalously high exchange rates appear to be the combined effects of enormously high gradient values and high transfer coefficients. While the emissions of Hg occurred constantly during the whole study periods, the occurrences of dry deposition events were observed most intensively during very limited time periods(3/29 and 4/3). The results of our study cleary indicated that the studied area is a strong local areal source, while exhibiting great potential as a major sink simultaneously.

• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.234-241
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• 2020

This paper presents a thermodynamic performance analysis of a combined cycle consisting of regenerative organic Rankine cycle (ORC) and liquefied natural gas (LNG) Rankine cycle to recover low-grade heat source and the cold energy of LNG. The mathematical models are developed and the system performances are analyzed in the aspect of thermodynamics. The effects of the turbine inlet pressure and the working fluid on the system performance such as the mass flow rates, heat transfers at heat exchangers, power productions at turbines, and thermal efficiency are systematically investigated. The results show that the thermodynamic performance of ORC such as net power production and thermal efficiency can be significantly improved by the regenerative ORC and the LNG cold energy.

• 천문학회보
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• 제43권2호
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• pp.41.1-41.1
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• 2018

We constrain cosmological parameters by combining three different power spectra measured from galaxy clustering, galaxy-galaxy lensing, and cosmic shear using the Deep Lens Survey (DLS). Two lens bins (centered at z~0.27 and 0.54) and two source bins (centered at z~0.64, and 1.1) containing more than one million galaxies are selected to measure the power spectra. We re-calibrate the initial photo-z estimation of the lens bins by matching with SHELS and PRIMUS and confirm its fidelity by measuring a cross-correlation between the bins. We also check the reliability of the lensing signals through the null tests, lens-source flipping and cross shear measurement. Residual systematic errors from photometric redshift and shear calibration uncertainties are marginalized over in the nested sampling during our parameter constraint process. For the flat LCDM model, we determine S_8=sigma_8(Omega_m/0.3)^0.5=0.832+-0.028, which is in great agreement with the Planck data. We also verify that the two independent constraints from the cosmic shear and the galaxy clustering+galaxy-galaxy lensing measurements are consistent with each other. To address baryonic feedback effects on small scales, we marginalize over a baryonic feedback parameter, which we are able to constrain with the DLS data alone and more tightly when combined with Planck data. The constrained value hints at the possibility that the AGN feedback in the current OWLS simulations might not be strong enough.

• 천문학논총
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• 제30권2호
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• pp.629-631
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• 2015

In this proceedings, preliminary results of the KVN Source-Frequency Phase-Referencing (SFPR) observation of 3C 66A and 3C 66B are presented. The motivation of this work is to measure the core-shift of these 2 sources and study the temporal evolution of the jet opacity. Two more sources were observed as secondary reference calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. Our preliminary results show that after using the observations at the lower frequency to calibrate those at the higher frequency of the same source, the residual visibility phases for each source at the higher frequencies became more aligned, and the coherence time became much longer; also, the residual phases for different sources, within 10 degrees angular separations, follow similar trends. After reference to the nearby calibrator, the SFPRed maps were obtained as well as the astrometric measurements, i.e. the combined coreshift. The measurements were found to be affected by structural blending effects because of the large beamsize of KVN, but this can be corrected with higher resolution maps (e.g. KAVA maps).

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권5호
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• pp.249-257
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• 2002

In this paper, a novel control scheme compensating source voltage unbalance and harmonic currents for the combined system of series active and shunt passive power filter is proposed, where no low/high-pass filters are used in deriving the reference voltage for compensation. The phase angle and the reference voltages compensating for harmonic current and unbalanced voltage are derived from the positive sequence component of the unbalanced voltage set, which is simply obtained by using digital all-pass filters. In order to remove the phase delay in generating the reference voltage for compensation, the reference of 5th and 7th harmonic components is predicted one-sampling ahead. The validity of the proposed scheme has been verified for 3[kVA] proto-type active power filter system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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• pp.975-979
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• 2001

In connection with the monitoring of the insulation degradation of large power apparatus in order to predict their expected service failures, a statistical treatment, such as phase resolved partial discharge analysis (PRPDA), has been established for the on-line monitoring system during the past decades. However, this method has shown some inconveniences to identify the nature of the PD source in power apparatus. In this regard, a novel approach based on the chaotic analysis (CAPD) is proposed describing the fundamental ideas, outcomes and different viewpoints from the conventional PRPDA. As a model for the possible defects causing sudden failures in service, three types of specimen are prepared. And partial discharge signals, originated from those samples, are measured and analyzed by means of CAPD. Throughout this work, it seems that the correlation between the consecutive PD pulses, depending on the nature of PD, could be clarified by CAPD. Thereffre, it could be considered that the nature of PD source can be identified more distinctively when the CAPD is combined with PRPDA.

• Nuclear Engineering and Technology
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• 제31권3호
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• pp.294-302
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• 1999

The influence of source term release parameters on offsite health effects was examined for the YGN 3&4 nuclear power plants. The release parameters considered in this study are release height, heat content, and release time. The effects of core inventory change as a function of fuel burnup was also examined. The health effects by the change of release parameters are early fatalities, cancer fatalities, and early fatality distance. The results showed that early fatalities and early fatality distance decrease as release height increases, although it does not have significant influence on cancer fatalities. The values of both early and late health effects decrease as heat content increases. As release time increases, health consequence shows maximum value in 2 hours of release time and then decreases rapidly. As fuel burnup increases, early fatalities decrease rapidly, while cancer fatalities increase rapidly. Both cases show little variation afterward. Early fatality distance is almost same in all fuel turnup history. The information obtained through this research is very useful in developing strategies for reducing offsite consequences when combined with the influence of weather conditions on offsite risks.

• 전기학회논문지
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• 제56권4호
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• pp.716-723
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• 2007

This paper suggests of a 3-phase 3-wire unified active power filter. The system is composed of a series active power filter and a parallel active power filter. The proposed series active power filter compensating unbalance source voltage and current harmonics of the parallel active power filter improves power factor. The proposed algorithm which improves for power factor and harmonic reduction are calculated by the performance function, and which compensates for the unbalanced source voltage is calculated based on the symmetrical component analysis. We composed a combined system of the series active power filter and parallel active power filter to confirm a validity of the proposed control methods. The effectiveness of the proposed algorithm is confirmed by the experiments.