• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.5
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• pp.63-71
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• 2005

In-situ soil remediation mechanism through the vertical drains (VDs) is analyzed with numerical model as the error and complementary error function. Results from in-situ test and analysis indicate that the contaminant concentration ratio as initial one ( C/$C_0$) increases as the radius ratio ( r/R) increases from the injection well, and also increases as the depth ratio ( z/ H) increases from the top of contaminated area. The elapse time needed to attain $50\%$ and $90\%$ clean up level ($ t_{50},\;t_{90}$) increases as the radius ratio ( r/R) and the depth ratio ( z/ H) increase. As above results, the procedure of soil flushing in contaminated area using vertical drains makes progress from the top of injection well to the bottom of extraction well.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.90-91
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• 2023

대기오염에 대한 사회적 관심이 증가함에 따라 미세먼지 관련 IoT 가전제품의 수요가 증가하였다. 이에 따라 IoT 제품에서 수집되는 실내 데이터의 정확성을 높이기 위해 미세먼지 센서 외의 추가적인 센서를 사용하여 관측치를 예측하는 연구가 진행되고 있다. 하지만 기존 연구에서는 센서의 물리적 한계를 인공지능을 통하여 극복하려는 시도는 존재하지 않는다. 본 논문에서는 추가적인 센서를 사용하지 않고 단일 센서만을 사용하여 미세먼지 종류의 구분 가능성을 판단하고자 하며 이를 정확도 기반으로 비교 실험을 진행하여 가장 좋은 성능을 나타낸 딥러닝 기반 분류모델을 선정한다.

• Korean Journal of Materials Research
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• v.20 no.2
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• pp.90-96
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• 2010

The recirculating electrochemical flow reactor developed at UCLA has been employed to fabricate nanostructured GMR multilayers. For comparison, Ni/Cu multilayers have been electrodeposited from a single bath, from dual baths and from the recirculating electrochemical flow reactor. For a magnetic field of 1.5 kOe, higher GMR (Max. -5%) Ni/Cu multilayers with low electrical resistivity (< $10\;{\mu}{\Omega}{\cdot}cm$) were achieved by the electrochemical flow reactor system than by the dual bath (Max. GMR = -4.2% and < $20\;{\mu}{\Omega}{\cdot}cm$) or the single bath (Max. GMR = -2.1% and < $90\;{\mu}{\Omega}{\cdot}cm$) techniques. Higher GMR effects have been obtained by producing smoother, contiguous layers at lower current densities and by the elimination of oxide film formation by conducting deposition under an inert gas environment. Our preliminary GMR measurements of Ni/Cu multilayers from the electrochemical flow reactor obtained at low magnetic field of 0.15 T, which may approach or exceed the highest reported results (-7% GMR) at magnetic fields > 5 kOe.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.323-330
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• 2019

The purpose of this study was to investigate the effect of body mass index(BMI) and waist circumference(WC) on hemoglobin(Hb) in Korean Adult. This study analyzed the data of 2015, The Sixth KNHANES. Data were analyzed using descriptive statistics, t-test, ANOVA and Scheffe's test, Pearson correlation coefficient and multivariate logistic regression analysis(SPSS 25.0). The major findings, The subject's Hb In BMI, obese was the highest(F=97.862, p<0.001). The Hb In WC, $WC{\geq}90cm$ was higher for male(t=4.909, p<0.001), and $WC{\geq}85cm$ was higher for female(t=5.088, p<0.001). Hb has a significant positive correlated with BMI(r=0.188, p<0.001), WC(r=0.298, p<0.001). In male, Hyperhemoglobinemia was 2.30 times(p<0.001) higher in obese and 1.81 times(p<0.001) higher in $WC{\geq}90cm$. In female, Hyperhemoglobinemia was 1.99 times(p=0.002) higher in overweight, 5.66 times(p<0.001) higher in obese, and 4.27 times(p<0.001) higher in $WC{\geq}85cm$. In conclusion, adult obesity prevention and management programs should include exercises, diets, and education, and exercise interventions specifically for eliminating abdominal obesity.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.241-242
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• 2002

Wear behavior or SiC-particle reinforced aluminum matrix composites (MMC) were investigated by pin-on-disk tests in vacuum with various pressures, argon, and air with various levels of humidity. The wear rate of 2024Al and MMC increased in the following order: in a vacuum at $5.0{\times}10^{-4}$ Pa, at 1.0Pa, in argon at 0% RH, in argon at 60% RH, in argon at 90% RH, in air at 0% RH, in air at 60% RH and in air at 90% RH. In other words, the influence or environment on wear becomes stronger in the following order: moisture, oxygen, and a combination of moisture and oxygen. In various environments, the difference of the wear rate of 2024Al and MMC was compared. In argon and air at 0% RH, the wear rates of MMC were higher than that of 2024Al. In contrast, in argon and air at 60, 90% RH, the wear rates of MMC were lower than that of 2024Al.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.18 no.2
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• pp.77-86
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• 2022

This study investigates the effect of the diameter and thickness on crack initiation location and orientation of 90° elbows under in-plane mode displacement-controlled cyclic bending loads. Finite element (FE) analysis of cyclic failure test is conducted for elbow specimens under in-plane mode displacement-controlled cyclic bending to identify the parameters affecting crack location and orientation. Furthermore, parametric FE analysis of the pipe elbows with various pipe nominal sizes and Schedules is performed, and the crack location and orientation from the results of FE analysis are determined. It is found that the crack location and orientation in the pipe elbows are determined mianly by the radius to thickness ratio of pipe elbows (R_m/t). It is also found that the presence of internal pressure slightly increases the value of R_m/t at which the failure mode changes.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1039-1046
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• 2003

In a trial involving 240pigs, the proximate composition, physico-chemical properites, color, amino acid composition and fatty acid composition of loin muscle were investigated in feeding various finished pig feeds. The treatments included feeding control) the low-nutrient density diet(2,960cal/kg ME, 12.25% CP, 0.41% lysine and 0.70% Ca), T1) the medium-nutrient density diet(3,220cal/kg ME, 15.50% CP, 0.87% lysine and 0.90% Ca) and T2) the hight-nutrient density diet(3,350cal/kg ME, 17.50% CP, 1.05% lysine and 0.90% Ca). The crude ash contents of T1 were significantly(p〈0.05) higher than those of control and T2. The pH$_{u}$ of T2 were significantly higher than those of control and T1, but cooking loss were significantly(p〈0.05) lower than those of control. In compositions amino acid, aspartic acid, threonine, iso-leucine and histidine of T2 were higher than those of control, but proline and glycine were significantly(p〈0.05) lower then those of control. The oleic acid(18:1) contents of control were significantly higher than those of T1 and T2, but the contents of linoleic acid(C18:2) and arachidonic(C20:4) acid were significantly(p〈0.05) lower. Inconclusion, the results of the experiments suggest that the high-nutrient density diet for pigs tended to improve the postmortem pH$_{u}$ and cooking loss.

• Korean Journal of Poultry Science
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• v.34 no.1
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• pp.53-56
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• 2007

An experiment was conducted to investigate the effect of ME and crude protein (CP) content of diet on the performance and production cost of white semibroiler chickens. Three hundred sixty hatched white semibroiler chickens (Hy-Line $female\;{\times}\;Ross^{(R)}$ male) were assigned to low dietary treatments of different metabolizable energy (ME) value and crude protein (CP) content: T1; ME 3,040 and 3,070 kcal/kg, CP 21.40 and 20.86%, T2; ME 2,950 and 3,000 kcal/kg, CP 20.62 and 19.70%, T3; ME 2,950 and 3,000 kcal/kg, CP 19.90 and 18.70% and T4; ME 2,900 and 2,920 kcal/kg, CP 18.50 and 18.00% for starter diet ($0{\sim}1st$ wk) and power diet ($2{\sim}5th$ wk), respectively There were significant (P<0.01) differences among treatments in weight gain, feed intake and feed conversion ratio. T1 was significantly higher in weight gain and feed intake and love. in feed conversion ratio than other treatments. Production index of T1 (153.42) was far greater than T2 (112.13), T3 (108.40) and T4 (100.95). It was concluded that semibroilers required similar ME and CP to those of regular commercial broilers (highbro).

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.77-84
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• 2018

In this paper, the circular polarization microstrip patch antenna using the T-junction power divider is proposed. The operating frequency of the proposed antenna is ISM band of 2.4GHz and the circular polarization is induced by feeding a phase difference of $90^{\circ}$ in two edges. The structure of the antenna consists of a general patch and a T-junction power divider. Furthermore, to optimize the proposed antenna, it is analyzed the reflection coefficient, the axial ration and the radiation pattern. The impedance bandwidth of the antenna is observed to be 40MHz within a range of 2.39 to 2.43GHz, similarly, the axial ratio bandwidth is observed having the bandwidth of about 12MHz in 2.398 to 2.410GHz range. The radiation pattern of the antenna is seen to be right circular polarization. Furthermore, the gain of the antenna is observed to be 2.04 and 3.4dBic at XZ and YZ-plane, respectively.

• Computers and Concrete
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• v.29 no.1
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• pp.31-45
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• 2022

Experimental and numerical simulation were used to investigate the effects of angle and number of T shape non-persistent crack on the shear behaviour of crack's bridge area under uniaxial compressive test. concrete samples with dimension of 150 mm×150 mm×40 mm were prepared. Within the specimen, T shape non-persistent notches were provided. 16 different configuration systems were prepared for T shape non-persistent crack based on two and three cracks. In these configurations, the length of cracks were taken as 4 cm and 2 cm based on the cracks configuration systems. The angle of larger crack related to horizontal axis was 0°, 30°, 60° and 90°. Similar to cracks configuration systems in the experimental tests, 28 models with different T shape non-persistent crack angle were prepared in numerical model. The length of cracks were taken as 4 cm and 2 cm based on the cracks configuration systems. The angle of larger crack related to horizontal axis was 0°, 15°, 30°, 45°, 60°, 75° and 90°. Tensile strength of concrete was 1 MPa. The axial load was applied to the model. Displacement loading rate was controlled to 0.005 mm/s. Results indicated that the failure process was significantly controled by the T shape non-persistent crack angle and crack number. The compressive strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the crack number and crack angle. The strength of samples decreased by increasing the crack number. In addition, the failure pattern and failure strength are similar in both methods i.e. the experimental testing and the numerical simulation methods (PFC2D).