• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1175-1182
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• 2005

Using KUCCS, which enables real-time monitoring and controlling, the various boundary condition and in-situ field stress condition was simulated, to derive the correlation among ${{\sigma}_v}'-Dr-N$in domestic sandy soils. Soil specimens, having various relative density and confined stress, were formulated to evaluate N-value from the SPT. and Pile Driving Analyzer, PDA, was employed as a measuring device for the energy transfer efficiency in the rod. From the quantitative analysis of N-value, the correlating equation, $N_{60}/{D_r}^2=16.35+14.45{{\sigma}_v}'$ was obtained on the basis of Skempton's method(1986). More reliable soil parameters can be obtained from the N-value by using this study which considered regional characters and the correlation among ${{\sigma}_v}'-Dr-N$.

• 한국도로학회논문집
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• 제8권3호
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• pp.115-127
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• 2006

현재 중부내륙 고속도로 시험도로(test road)에는 환경하중에 대한 도로 포장체의 환경적인 거동 특성을 파악하기 위하여 다져진 노상토에 WCR형태의 함수량계로 측정되는 체적 함수량이 현장 밀도의 영향등으로 부정확하게 예측되는 경향을 나타내고 있다. 따라서 본 연구에서는 흙의 특성과 현장 밀도를 고려하여 현장에 적합한 함수량 보정을 실내 및 현장시험을 각각 실시하고 이를 토대로 보정방정식을 제안하였다. 연구 결과 보정된 함수량은 현장의 측정치에 근접하게 판명되었다. 따라서 WCR을 활용하여 다짐된 노상토 지반의 체적 함수량을 측정시 사용된 흙의 종류 및 다짐조건 등이 고려되어야 한다.

• 대한디지털의료영상학회논문지
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• 제3권1호
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• pp.126-132
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• 1997

Purpose : To apply to Program of Auto processor quality control after comparison of Film density variations with amendments to Auto density by using Check density program and Adjust density program of calibration mode into the Laser imager. Methods : Observe Check and Adjust density variations on the Control chart with standard step and value during seven months from December, 1995 to June, 1956 extending twice a week. (1) Measure density value on the steps after printing out 17-step sensitometric pattern of the Check density program. (2) In the same way, measure density values after amending density by using Adjust density program If they are exceeding allowable error limit. Results : In case of Check density program, the exceeding limit rates of Density difference(DD) and Middle density(MD) are: FL-IM3543 DD=75%. MD=72.5%, FL-IMD DD=0%. MD=30.8%(14.5%) After amending density by using Adjust density program, the exceeding limit rates of all both Laser imager were zero percent. The standard deviations are show lower FL-IM D than FL-IM3543 on the Check density control chart, but higher on the Adjust density control chart. Conclusion : (1) Check density variations by printingout sensitometric pattern extending once a week at least for quality control of the Laser imager. (2) In case of a dusty place, check the Laser beam transmission after cleaning Laser optical unit extending once a month. (3) Be sure to measure and check density values by using adjust density program if they are exceeding allowable error limit. (4) Maintain much better film density by performing the adjust density program even if check density values are existed within normal limit.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.426-439
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• 2018

Purpose: To continuously monitor soil and climatic properties, a data acquisition system (DAQ) was developed and tested in plum farms (Gyewol-ri and Haechang-ri, Suncheon, Korea). Methods: The DAQ consisted of a Raspberry-Pi processor, a modem, and an ADC board with multiple sensors (soil moisture content (SEN0193), soil temperature (DS18B20), climatic temperature and humidity (DHT22), and rainfall gauge (TR-525M)). In the laboratory, various tests were conducted to calibrate SEN0193 at different soil moistures, soil temperatures, depths, and bulk densities. For performance comparison of the SEN0193 sensor, two commercial moisture sensors (SMS-BTA and WT-1000B) were tested in the field. The collected field data in Raspberry-Pi were transmitted and stored on a web server database through a commercial communications wireless network. Results: In laboratory tests, it was found that the SEN0193 sensor voltage reading increased significantly with an increase in soil bulk density. A linear calibration equation was developed between voltage and soil moisture content depending on the farm soil bulk density. In field tests, the SEN0193 sensor showed linearity (R = 0.76 and 0.73) between output voltage and moisture content; however, the other two sensors showed no linearity, indicating that site-specific calibration is important for accurate sensing. In the long-term monitoring results, it was observed that the measured climate temperature was almost the same as website information. Soil temperature information was higher than the values measured by DS18B20 during spring and summer. However, the local rainfall measured using TR 525M was significantly different from the values on the website. Conclusion: Based on the test results obtained using the developed monitoring system, it is thought that the measurement of various parameters using one device would be helpful in monitoring plum growth. Field data from the local farm monitoring system can be coupled with website information from the weather station and used more efficiently.

• 한국지반신소재학회논문집
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• 제12권2호
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• pp.1-11
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• 2013

지하매설구조물인 상수도관 주변 지반의 간극수 동결로 상수도관의 변형에 영향을 미칠 수 있다. 이에 최근에는 현장 계측을 통한 포장 하부구조체의 함수비를 주기적으로 측정하기 위해서 미국 Campbell사의 TDR(time domain reflectometry) CS616 함수량계와 독일의 IMKO사 제품의 TRIME FM를 이용한 수동 함수량계 TRIME P3, T3 Probe를 사용하고 있다. 일반적으로 TDR 함수량계와 TRIME 수동 함수량계는 흙의 종류, 입도, 다짐도, 온도 등에 의해 오차가 유발될 수 있기 때문에, 현장의 시료를 사용하여 TDR 함수량계의 실내보정실험을 반드시 수행해야 한다. 즉, TDR함수량계의 매뉴얼에서는 일반적인 흙의 보정방정식을 제안하고 있지만 현장 적용시에는 반드시 보정실험을 수행하도록 권고하고 있다. 본 연구에서는 상수관 등 지하매설구조물의 주변의 다양한 채움재료를 사용하여 실내 보정 실험을 수행하였으며, 이 결과로부터 TDR함수량계인 CS616, TRIME-T3, TRIME-P3의 보정모델식을 제안하였으며, 보정식에 대한 현장검증을 수행하였다.

• 방사성폐기물학회지
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• 제14권1호
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• pp.57-61
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• 2016

The Tomographic Gamma Scan (TGS) technique partitions radioactive waste drums into $10{\times}10{\times}16$ voxels and assays both the density and concentration of radioactivity for each voxel thus providing for improved accuracy, when compared to the traditional Non-Destructive Assay(NDA) techniques. It could decrease the degree of precision measurement since there is a trade-off between spatial resolution and precision. This latter drawback is compensated by expanding the Region of Interest (ROI) that differentiates the full energy peaks, which, in turn, results in an optimized degree of precision. The enlarged ROI, however, increases the probability of interference among those nuclides that emit energies in the adjacent spectrum. This study has identified the cause of such interference for the reference nuclide of the TGS technique, $^{137}Cs$ (661.66 keV, half-life 30.5 years), to be $^{110m}Ag$ (657.75 keV, half-life 249.76 days). A new calibration method of determining the optimized ROI was developed, and its effectiveness in accurately characterizing $^{137}Cs$ and eliminating the interference was further ascertained.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.59-65
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• 1997

The calibration of O.M.D is carried out experimentally and is analysed theoretically. O.M.D experimentally measures the change in optical density of artificially contaminated oil which contains Fe powder of 5, 10, 20, 30, 40, 50, 70, 100, 200 ppm. The change in optical density, D$_1$ means the logarithmic transmittance of I$_0$ over $I_1 D_2$ denotes the logarithmic transmittance I$_2$ over I$_1$ on electromagnetic force which arranges the ferrous particles along the line of magnetic force. The theoretical D$_1$ which increases linearly as increasing Fe concentrations, is analysed by light attenuation theory. The difference between theoretical D$_1$ and experimental D$_1$ is due to the attenuation of micro bubbles and the agglomeration of fine particles in the sample oil. The calibrated O.M.D is applied to the sample oil from the high-powered diesel engine. Also the results are compared with those out of the off-line techniques such as JOAP and ICP.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.60-69
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• 2003

The simplified two-color method is proposed which can estimate the temperature distribution and the soot density of the whole flame with the image analysis of the high-speed photographs. The factors influenced on its processing were examined, for example, the selection of the wave length, the kind of films, the preparation of the calibration curve between the radiance of flame and the luminance temperature. The simplified two-color method reported in this paper can be used as a tool for the improvement of the combustion process in direct injection diesel engine.

• 대한토목학회논문집
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• 제14권1호
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• pp.203-216
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• 1994

현재 국내에서 사용중인 흙의 다짐관리 방법에는 실험실내에서 시행하는 흙의 다짐 시험 (KSF 2312)과 함수량시험(KSF 2306), 현장에서 모래치환법에 의한 흙의 단위중량 시험 방법 (KSF 2311)이 었다. 이러한 시험방법들은 소요시간이 길고 작업이 번잡하므로 최근과 같이 빠른 사공속도가 요구되는 대규모 토공관리에는 부적합하며 측정자의 개인오차 등으로 인한 신뢰성도 낮다. 최근 대부분의 외국에서는 방사성 동위원소(RI)를 이용한 흙의 밀도/함수량 측정계기를 성토시공관리에 이용하고 있으나 국내에서는 이에 대한 기초연구의 부족 등의 이유로 건설분야에서의 RI계기 이용이 제한되어 있는 실정이다. 따라서 본 연구에서는 국내 토질 기술자들에게 RI계기를 소개하고 RI계기를 보다 효율적이고 안전하게 사용할 수 있도록 RI계기에 대한 기초연구를 실시하였다. 이를 위해 우선적으로 RI계기의 검증연구와 현장 적용성에 대한 검토를 실시한 후, 국내 토질에 적합한 교정식을 도출하였다.

• 생태와환경
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• 제41권2호
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• pp.247-263
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• 2008

A two-dimensional (2D) reservoir hydrodynamics and water quality model, CE-QUAL-W2, is employed to simulate the hydrothermal behavior and density current regime in Andong Reservoir. Observed data used for model forcing and calibration includes: surface water level, water temperature, dissolved oxygen and suspended solids concentration. The model was calibrated to the year of 2003 and verified with continuous run from 2000 till 2004. Without major adjustments, the model accurately simulated surface water levels including the events of large storm. Deep-water reservoirs, like Andong Reservoir, located in the Asian Monsoon region begin to stratify in summer and overturn in fall. This mixing pattern as well as the descending thermocline, onset and duration of stratification and timing of turnover phenomenon were well reproduced by the Andong Model. The temperature field and distinct thermocline are simulated to within $2^{\circ}C$ of observed data. The model performed well in simulating not only the dissolved oxygen profiles but also the metalimnetic dissolved minima phenomenon, a common1y occurring phenomenon in deep reservoirs of temperate regions. The Root Mean Square Error (RMSE) values of model calibration for surface water elevation, temperature and dissolved oxygen were 0.0095 m, $1.82^{\circ}C$, and $1.13\;mg\;L^{-1}$, respectively. The turbid storm runoff, during the summer monsoon, formed an intermediate layer of about 15 m thickness, moved along the metalimnion until being finally discharged from the dam. This mode of transport of density current, a common characteristic of various other large reservoirs in the Asian summer monsoon region, was well tracked by the model.