• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.148-148
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• 2012

A cutoff probe is the novel diagnostic method to get the absolute plasma density with simple system and less assumption. However, high density of ion flux from plasma on probe tip can make the error of plasma density measurement because the dielectric material of probe tip can be damaged by ion flux. We proposed a shielded cutoff probe using the ceramic tube for protection from ion flux. The ceramic tube on probe tip can intercept the ion flux from plasma. The transmitted spectrum using the shielded cutoff probe is good agreement with E/M wave simulation result (CST Microwave Studio) and previous circuit simulation of cutoff probe [1]. From the analysis of the measured transmitted spectrum base on the circuit modeling, the parallel resonance frequency is same as the unshielded cutoff probe case. The obtained results of electron density is presented and discussed in wide range of experimental conditions, together with comparison result with previous cutoff method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2079-2084
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an embryo cell is currently performed by a skilled operator, relying on visual feedback information only. Accurately measuring cellular forces is a requirement for minimally invasive cell injections. Moreover, the cellular force sensing is essential in investigating the biophysical properties for cell injury and membrane modeling studies. This paper presents cellular force measurements for the force feedback-based biomanipulation. Cellular force measurement system using piezoelectric polymer sensor is implemented to measure the penetration force of a zebrafish egg cell. First, measurement system setup and calibration are described. Second, the force feedback-based biomanipulation is experimentally carried out. Experimental results show that it successfully supplies real-time cellular force feedback to the operator at tens of uN and thus plays a main role in improving the reliability of biological cell injection tasks.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.4
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• pp.261-267
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• 2009

Due to the measurement noise or system noise, the performance of photovoltaic power generation system can be degraded. If this noise is contained in the solar array voltage measurement signal, the correct operation of the maximum power point tracker can not be guaranteed. The application of the extended Kalman filter to the photovoltaic system can obtain enhanced states estimation result. The Kalman filter provides a recursive solution to optimally estimate from random noise signals. Additionally, as a consequence of Kalman filter, the unmeasurable state such as inductor current can be estimated without current sensor. The methods for system modeling and extended Kalman filter design are presented and the experimental results verify the validity of the proposed system.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.3
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• pp.176-182
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• 2021

This research proposes a high-frequency circuit that can accurately predict the differential mode noise of single-phase inverters at the circuit design stage. Proposed single-phase inverter high frequency circuit in the work is a form in which harmonic impedance components are added to the basic single-phase inverter circuit configuration. For accurate noise prediction, parasitic components present in each part of the differential noise path were extracted. Impedance was extracted using a network analyzer and Q3D in the measurement range of 150 kHz to 30 MHz. A high-frequency circuit model was completed by applying the measured values. Simulations and experiments were conducted to confirm the validity of the high-frequency circuit. As a result, we were able to predict the resonance point of the differential mode voltage extracted as an experimental value with a high-frequency circuit model within an approximately 10% error. Through this outcome, we could verify that differential mode noise can be accurately predicted using the proposed model of the high-frequency circuit without a separate test bench for noise measurement.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.151-164
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• 2013

Multidimensional dynamic water quality model of organic matter and trophic state was applied to the Han River system. The model was calibrated using field measurement data obtained during the year of 2007. The model results showed reasonable performance in predicting temporal variations of TN, TP, Chl-a and BOD concentrations. The applied integrated modeling system can be effectively used to simulate water quality as well as hydrodynamic and water temperature for river-lake continuous system in the Han River. Utilizing the calibrated model, we analyzed the spatial and temporal distributions of TN, TP, Chl-a and BOD concentrations in the Han River system. The temporal variations of water quality at each river reach and lake were effectively simulated with the developed model and spatial distribution of water qualities in the Han River system could be compared. The multidimensional dynamic modeling system can simulate the water qualities of entire waterbody where Lake Paldang and the incoming flows are included using single modeling system. So it can be effectively used for integrated water quality management of the Han River system.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.893-901
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• 2012

Aircraft noise model such as FAA Integrated Noise Model(INM) has recently been used for forecasting the impact of noise in a residential area near an airport and quantifying the effect of various options for noise mitigation. The noise modeling should be reliable and precise in order to ensure the quality of the results provided. In this study, the validation of the noise levels simulated by the INM against measurement data recorded continuously at multiple monitoring sites was discussed. As a result of validation, the quality of the input data used as a fixed point profiles for the INM was enhanced. The noise contour maps were designed as a way to evaluate the aircraft noise of the vicinity of the airfield. The results of this study indicate that the validation of aircraft noise model by the measurement data would be required for the accurate assessment of the aircraft noise levels.

• Fire Science and Engineering
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• v.28 no.1
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• pp.37-43
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• 2014

The high predictive performance of fire detector models is essentially needed to assure the reliability of fire and evacuation modeling in the process of Performance-Based fire safety Design (PBD). The main objective of the present study is to measure input information in order to predictive the accurate activation time of fixed temperature heat detectors adopted in Fire Dynamics Simulator (FDS) as a representative fire model. To end this, Fire Detector Evaluator (FDE) which could be measured the device properties of detector was used, and the spot-type fixed temperature heat detectors of two thermistor types and one bimetal type were considered as research objectors. Activation temperature and Response Time Index (RTI) of detectors required for the fire modeling were measured, and then the RTI was measured for ceiling jet flow and vertical jet flow in consideration of the install location of detectors. The results of fire modeling using measured device properties were compared and validated with the experimental results of full-scale compartment fires. It was confirmed that, in result, the numerically predicted activation time of detector showed reasonable agreement with the measured activation time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.535-540
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• 2006

The relationship between the observable noise model and the satellite elevation angle can be modeled quite well by an exponential function.[Jin, 1996] Noise size and dependence on the elevation angle are, however, different for each observation and receiver type. Therefore, the coefficient determination of this model is an issue, and various methods including PR-CP, single difference, and time difference have been suggested. The limitations of them are difficulty to model the carrier phase noise and to eliminate bias. To overcome these disadvantages for using Jin's model, we suggest zero baseline double difference (DD) and noise sorting algorithm. Data DD technique in zero baseline is useful to eliminate all the troublesome GPS biases, and the remaining error is the sum of GPS measurement noises from two satellites. These DD residuals for hours should be sorted by the combination of satellite elevation angles, and then variance value of the residual for each combination can be estimated. Using these values, we construct an over-determined linear equation whose solution is a set of noise variance for each satellite elevation angle. With 24hr Trimble 4000ssi data, we easily worked out the coefficients of the noise model not only for pseudorange but also for carrier phase. We estimated the standard deviation of the measurement DD using our model, and plotted 1 and 3 sigma lines for every epoch to verify the representation of the residual error. 63.3% of pseudorange residual and 65.9% of phase error did not exceed the 1 sigma lines. Additionally, 99.2% and 99.5% of them lied within 3sigma line. These figures prove that the Gaussian property of measurement noise, and that the suggested model by our algorithm corresponds to the observable noise information.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.1-6
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• 2018

With the increase of the elderly population, demand for improvement of quality of life and measurement of mental state has increased. However, much of the self-reported diagnosis does not reflect cognitive impairment. This study aims to measure the dwelling depression by applying K-HTP and verify the validity. 301 persons over 65 years old who live as single and couple households in Daejeon and surrounding districts were surveyed during 22 January to 2 February, 2018. The correlations between the dwelling depression and K-HTP are clarified and the validity was evaluated. The correlations between the geriatric dwelling depression index(GDDI) and the GDDI based on K-HTP(GDDI-K) are clarified and the accuracy was analyzed. The results showed that the K-HTP can be utilized to measure the dwelling depression. We suggested a new measurement tool and provide further benefits for researches on diagnoses using the projective method.

• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.532-540
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• 2013

Background: Exposure factors for consumer products have been developed since the 1980s. Such exposure factors are important in risk assessment. Since the exposure/use patterns of consumer products in a country may reflect its respective cultural, meteorological, and socio-economic circumstances, unique Korean exposure factors for consumer products are needed. Such exposure factors are required for newly-enacted chemical regulations in Korea. For this review, published papers and survey reports on exposure factors of consumer products were examined for their assessment methodologies. Results: Investigation into exposure factors for consumer products used a variety of methods: home visit, online, telephone, and mail surveys using questionnaires; face to face interviews; modeling using a constructed database; and direct measurement. To collect more accurate exposure information or to check the reliability of the sampling method, some studies were repeated using the same questionnaire, in-home observation, direct measurement of usage, and videotaping. In Korea, nationwide exposure surveys were conducted five times over five years to obtain Korean exposure factors. However, with the exception of the $5^{th}$-year study, the surveys were online questionnaires and only the $5^{th}$-year study validated the accuracy of exposure information by re-visits and direct measurement. Conclusion: Accurate exposure factors are an essential part of risk assessment to assure safe use of consumer products. For better and safer management of consumer products, accurate exposure factors in Korea should be assessed for various exposure pathways.