• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.291-298
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• 2001

It is very difficult to accomplish load tests of piles with large diameter constructed on the offshore area, because of requirement for large scaled loading equipment and bad testing conditions. Therefore, so far in many cases pile driving dynamic formulas have applied to quality control, and recently dynamic load test method is widely used for confirming bearing capacities of such piles. However, in cases of piles with very large diameter about 2,500mm, it is nearly impossible for regular type load test methods of piles such as static and dynamic to apply owing to very large design load. This is case studies of load tests such as modified static and dynamic load tests of piles and point load tests of rock samples for estimating rational allowable bearing capacity of very large diameter piles constructed on the marine area.

• ETRI Journal
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• 제39권6호
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• pp.859-865
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• 2017

This paper presents a method for determining the optimum active-area width (OAW) of solar cells in a module architecture. The current density-voltage curve of a reference cell with a narrow active-area width is used to reproduce the current density profile in the test cell whose active area width is to be optimized. We obtained self-consistent current density and electric potential profiles from iterative calculations of both properties, considering the distributed resistance of the contact layers. Further, we determined the OAW that yields the maximum efficiency by calculating efficiency as a function of the active-area width. The proposed method can be applied to the design of the active area of a dye-sensitized solar cell in Z-type series connection modules for indoor and building-integrated photovoltaic systems. Our calculations predicted that OAW increases as the sheet resistances of the contact layers and the intensity of light decrease.

• Journal of information and communication convergence engineering
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• 제16권4호
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• pp.258-263
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• 2018

Color Doppler sonography is a useful tool for examining blood flow and related indices. However, it should be done by well-trained operator, that is, operator subjectivity exists. In this paper, we propose an automatic blood flow area extraction method from brachial artery that would be an essential building block of computer aided color Doppler analyzer. Specifically, our concern is to examine hypertension suspicious (prehypertension) patients who might develop their symptoms to established hypertension in the future. The proposed method uses fuzzy C-means clustering as quantization engine with careful seeding of the number of clusters from histogram analysis. The experiment verifies that the proposed method is feasible in that the successful extraction rates are 96% (successful in 48 out of 50 test cases) and demonstrated better performance than K-means based method in specificity and sensitivity analysis but the proposed method should be further refined as the retrospective analysis pointed out.

• Journal of Welding and Joining
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• 제35권3호
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• pp.21-27
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• 2017

A soldering temperature of ($235{\pm}3$) $^{\circ}C$ is described in ISO 9455-15 for the copper corrosion test. However, this temperature is not suitable for performing lead-free solder pastes. We evaluated the compatibility of a lead-free solder paste in the experimental conditions of (Liquidus temperature + ($35{\pm}3$)) $^{\circ}C$. Based on the results after a Cu corrosion test, a proper temperature for Pb-free soldering was (melting point+($35{\pm}3$)) $^{\circ}C$. Criteria used to evaluate corrosion due to discoloration of flux residue is described in ISO 9455-15, but a more quantitative evaluation standard is needed. In this study, experimental error level was estimated by analyzing flux residue after a corrosion test for 72, 500 hours of specimens using EDS analysis with acceleration voltage. It was determined that the copper area at the flux residue boundary is suitable for the EDS analysis area.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.338-345
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• 2000

In this study, applicability of PMT in domestic area and test procedure were studied. At six test holes of three construction sites in Pusan, PMT using Elastometer-200 type was done. The problems during test were investigated and the test results were analysed. Limit pressure, p$\sub$ι/ could be determined by p- Δv/v method. Using PMT results, marine soil in Pusan could be classified approximately. Net limit pressure value was in the range of 6.4 ∼ 22.5 kg/$\textrm{cm}^2$ in clay, 2.2 ∼ 30.0 kg/$\textrm{cm}^2$ in sand, 13.0 ∼ 58.0 kg/$\textrm{cm}^2$ in weathered soil and 47.0 ∼ 190.0 kg/$\textrm{cm}^2$ in weathered rock. Also, E$\sub$m//p$\sub$ι/ value was in the range of 2.4 ∼ 7.0 in clay, 2.6 ∼ 12.1 in sand, 6.8 ∼ 17.1 in weathered soil and 7.2 ∼ 29.6 in weathered rock.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1289-1290
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• 2010

• 한국측량학회지
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• 제13권2호
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• pp.277-283
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• 1995

본 논문에서는 수치지형모델을 이용한 토공량 계산에서 격자간격지형의 보간방법, 토공양 산정방식 토공량의 정확도에 어떻게 영향을 주는 가를 연구하고자 하였으며, 이를 위하여 수치보험을 하였다. 우선 l0m간격의 정규격자로 구성된 지형의 수치모델에 대하여 이동평균법(Moving average)을 사용하여 2m, 5m, 10간격으로 보간 하였으며, 보간된 각 지형에 대해 양단면평균법, 중앙단면법, 각주공식, 심프슨 공식을 사용하여 토공량을 산정하였다. 이들 방법을 비교분석한 결과 이동평균법을 사용한 결과는 보간 방법에서는 1차식이, 토공량 계산방법에서는 양단면 평균법과 중앙단면법보다 각주공식과 심프슨 공식에서 정밀한 결과를 얻었다.

• 산업기술연구
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• 제32권A호
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• pp.87-94
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• 2012

For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation(CRS) test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. As results of numerical method, the volumetric ratio and reclamation velocity were obtained for the reclamation condition.

• 대한기계학회논문집A
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• 제30권9호
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• pp.1049-1061
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• 2006

In the study, the flow stress of material and friction condition were determined by using the cylinder compression test and numerical method. We proposed the flow stress equation including the initial yield strength to predict it from the upper bound method. The upper bound technique uses the velocity field which includes two unknowns to effectively express bulging. Also, inverse engineering technique uses the object function to minimize area enclosed by load-stroke curve. The friction factor is determined from the radius of curvature of the barrel by cylinder compression test. Flow stress and initial yield strength predicted from the above techniques are verified through the finite element simulation.

• 한국동물위생학회지
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• 제14권1호
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• pp.63-69
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• 1991

Antibiotic residues of raw milks collected in Anyang area were tested by TTC-reduction test, EEC-4plate method and TLC(SOS-kit ) method to improve and monitor the quality of milk. Antibiotic substances were not detected from 100 raw milk samples, but sulfamethazine was detected from only one sample(1.3PPM) by SOS test. Unclassified anti-microbic substances were detected from 22 samples by EEC-4 plate method. EEC-4 plate test was useful to categorize the species of antibacterial substances and SOS test was useful to detect the sulfamethazine field screening test.