• Title/Summary/Keyword: 전단감소

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A Study on the Distinct Element Modelling of Jointed Rock Masses Considering Geometrical and Mechanical Properties of Joints (절리의 기하학적 특성과 역학적 특성을 고려한 절리암반의 개별요소모델링에 관한 연구)

  • Jang, Seok-Bu
    • Proceedings of the Korean Geotechical Society Conference
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    • 1998.05a
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    • pp.35-81
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    • 1998
  • Distinct Element Method(DEM) has a great advantage to model the discontinuous behaviour of jointed rock masses such as rotation, sliding, and separation of rock blocks. Geometrical data of joints by a field monitoring is not enough to model the jointed rock mass though the results of DE analysis for the jointed rock mass is most sensitive to the distributional properties of joints. Also, it is important to use a properly joint law in evaluating the stability of a jointed rock mass because the joint is considered as the contact between blocks in DEM. In this study, a stochastic modelling technique is developed and the dilatant rock joint is numerically modelled in order to consider th geometrical and mechanical properties of joints in DE analysis. The stochastic modelling technique provides a assemblage of rock blocks by reproducing the joint distribution from insufficient joint data. Numerical Modelling of joint dilatancy in a edge-edge contact of DEM enable to consider not only mechanical properties but also various boundary conditions of joint. Preprocess Procedure for a stochastic DE model is composed of a statistical process of raw data of joints, a joint generation, and a block boundary generation. This stochastic DE model is used to analyze the effect of deviations of geometrical joint parameters on .the behaviour of jointed rock masses. This modelling method may be one tool for the consistency of DE analysis because it keeps the objectivity of the numerical model. In the joint constitutive law with a dilatancy, the normal and shear behaviour of a joint are fully coupled due to dilatation. It is easy to quantify the input Parameters used in the joint law from laboratory tests. The boundary effect on the behaviour of a joint is verified from shear tests under CNL and CNS using the numerical model of a single joint. The numerical model developed is applied to jointed rock masses to evaluate the effect of joint dilation on tunnel stability.

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Seasonal Changes of Species Composition and Standing Crop of Phytoplankton in the Ark Shell Scapharca broughtonii Farming Areas of Jinhae Bay (진해만 피조개 Scapharca broughtonii 양식장 식물플랑크톤의 종조성과 현존량의 월별변화)

  • Kim, Byoung-Hak;Min, Byeong-Hee;Choi, Nak-Joong;Oh, Bong-Se;Park, Ki-Yeol;Min, Kwang-Sik
    • Journal of Aquaculture
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    • v.21 no.3
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    • pp.157-166
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    • 2008
  • Species composition and standing crop of phytoplankton were investigated in the ark shell Scapharca broughtonii farming areas from March, 2006 to February, 2007 in Jinhae Bay. Water temperature ranged from 7.56 to $25.90^{\circ}C$, salinity from 13.74 to 34.78 psu, dissolved oxygen from 4.13 to 13.20 mg/L, chlorophyll $\alpha$ from 2.77 to 104.98 $mg/m^2$ and pH from 7.83 to 8.65. Dominant species was Nitzschia and Rhizosolenia from March to May, Skeletonama costatum and Prorocentrum from June to August, Skeletonama costatum, Thalassiosira, Chaetoceros from September to November and Thalassiosira, Chaetoceros from December to February. Colonial diatoms were more dominant than the single cell diatoms. Standing crop was the highest in July at three stations. Standing crop of Skeletonama costatum was the highest as 1,760.0 cells/mL at St. 1, 1,075.2 cells/mL at St. 2 and 698.4 cells/mL at St. 3 in July.

A Study on the Improvement of Capital Gains Tax Act through the Analysis of the Precedents of the cases of the lawsuit - Focusing on the transfer of inherited and donated property - (행정소송판례 검토를 통한 양도소득세법 개선방안 - 상속·증여받은 자산의 양도를 중심으로 -)

  • Yu, Soon-Mi;Kim, Hye-Ri
    • Management & Information Systems Review
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    • v.38 no.4
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    • pp.61-78
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    • 2019
  • When calculating gains from transfers of assets inherited or donated, the value recognized at the market price as of the date of inheritance or acquisition is recognized as the actual transaction value at the time of acquisition. However, Precedents for the appeal for review by the NTS, the request for adjudgment by the Tax Tribunal(TT) and the request of examination by the Board of Audit and Inspection of Korea(BAI) and the cases of the lawsuit have not shown a consistent results on how much such a the actual transaction value will be measured. This study investigates the operating state of the current tax appeal system using the statistical data of the TT, NTS, and BAI and cases of the lawsuit from 2008 to 2017, and suggests the Improvement of Capital Gains Tax Act on the transfer of inherited and donated property. As a result, total number of requested cases has diminished because cases of the pre-assessment review and the reconsideration appeal by the NTS have decreased steadily over the past decade, while the cases of the lawsuit and the administrative trials(the request for adjudgment by the TT, the appeal for review by the NTS, and the request of examination by the BAI) have been steadily increasing. Also This study found that more than 40% of the complainants proceeded with the cases of the lawsuit proceedings in disagreement with the disposition of tax dissatisfaction under the administrative trials. In addition, Even though the retrospective appraisal price is not recognized as the market price due to the strict interpretation of the tax regulations, it can be seen that it is interpreted as a more expanded concept in the application of the market price than the government office or the tax judge. Therefore, according to the precedents of the cases lawsuit, it is necessary to establish a regulation on the recognition of retroactive appraisal value.

Quality Characteristics of Low-fat Emulsified Sausage Containing Tomatoes during Cold Storage (토마토가 함유된 저지방 유화형 소시지의 냉장 저장 중 품질 특성)

  • Hoe, Soon-Ku;Park, Ki-Hoon;Yang, Mi-Ra;Jeong, Ki-Jong;Kim, Dong-Hoon;Choi, Jine-Shang;Jin, Sang-Keun;Kim, Il-Suk
    • Food Science of Animal Resources
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    • v.26 no.3
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    • pp.297-305
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    • 2006
  • This study was conducted to evaluate the quality characteristics of low-fat emulsion type sausages containing 0% tomato powder (C), 5.0% ground raw tomato paste (T1) and 0.5% freeze dried tomato powder (T2) during storage at $5{\pm}1^{\circ}C$ for 30 days. The crude protein content of T2 was significantly lower (p<0.05) than that of the other sausage types. Moisture, crude fat and crude ash contents of the sausages during storage were not affected by the addition of tomato. The pH and shear force ($kg/cm^2$) values of C were significantly higher (p<0.05) than those of T1 and T2. There was no significant difference among the different sausages in cooking loss, ranging from $13.00{\sim}14.98%$. The WHC values of T1 and T2 were significantly higher (p<0.05) than that of C. The values of TBARS were significantly (p<0.05) increased for ail sausages following storage. The TBARS value (mg MA/kg) of C was significantly higher (p<0.05) than those of T1 and T2 at 15 days of storage, however T1 was significantly higher (p<0.05) than the other sausages after 30 days of storage. The meat color values tended to decrease with increased storage time. Microorganism analysis revealed that all sausage types did not reach $4.4log_{10}CFU/g$ until 30 days of storage. The texture, brittleness, Hardness, and springiness of each sausage type were not significantly different after 1 day of storage, while the cohesiveness, gumminess and chewiness of T1 and T2 were significantly higher (p<0.05) than that of C. T1 and T2 sausages had a slightly higher score regarding color, aroma, tenderness and overall acceptability, however the sensory evaluation score among the different sausage types was not significantly different (p>0.05). In conclusion, low-fat sausage with added tomato showed higher lipid oxidative stability during storage than sausage to which no tomato was added.

Mucilage Separation of Korean Yam Using Microparticulation/Air Classification Process (초미세분쇄/공기분급을 이용한 마의 점질물 분리)

  • Lee, Boo-Yong;Park, Dong-June;Ku, Kyung-Hyung;Kim, Hyun-Ku;Mok, Chul-Kyoon
    • Korean Journal of Food Science and Technology
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    • v.26 no.5
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    • pp.596-602
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    • 1994
  • To separate and concentrate mucilage from yam(Dioscorea batatas DECNE), yam was dried, microparticulated using impact mill and air-classified at different air classifying wheel speed(ACWS) in classifier. As ACWS increased from 5,000 rpm to 22,500 rpm, the contents of dietary fiber, protein and lipid of air classified microparticles(ACM) increased remarkably. Especially the ACM with ACWS over 15,000 rpm showed 36.41% dietary fiber and 16.66% protein. The dietary fiber and protein components were concentrated to $2.5{\sim}9.0$ times as compared with whole yam powder. Concomitantly the non-fibrous carbohydrate decreased from 88.31% to 16.84. The damaged starch(%), WSI and WAI of ACM of ACWS over 15,000 rpm were $1.5{\sim}3.0$ times higher than those of ACM under ACWS 15,000 rpm. The apparent viscosity of ACM was 0.0800 Pa s over ACWS 15,000 rpm and 0.0080 Pa s under ACWS 15,000 rpm. Judging from viscosity of ACM, the mucilage component of yam was concentrated to 10 times. In conclusion, the optimum process to separate and concentrate the mucilage from yam consisted of the microparticulation to $5{\sim}30{\mu}m$ and the air-classification at ACWS over 15,000 rpm.

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Modeling Paddlewheel-Driven Circulation in a Culture Pond (축제식 양식장에서 수차에 의한 순환 모델링)

  • KANG Yun Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.6
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    • pp.643-651
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    • 2001
  • Paddlewheel-driven circulation in a culture pond has been simulated based on the depth integrated 2 dimensional hydrodynamic model. Acceleration by paddlewheel is expressed as shaft force divided by water mass discharged by paddlewheel blades. The model has been calibrated and applied to culture ponds as following steps:- i) The model predicted velocities at every 10 m along longitudinal direction from the paddlewheel. The model was calibrated comparing the results with the measured values at mass correction factor $\alpha$ and dimensionless eddy viscosity constant $\gamma$, respectively, in a range $15\~20$ and 6. ii) Wind shear stress was simulated under conditions of direction $0^{\circ}C,\;90^{\circ}C\;and\;180^{\circ}C$ and speed 0.0, 2.5, 5.0 and 7.5 m/s. Change rate of current speed was <$1\%$ at wind in parallel or opposite direction to the paddlewheel-driven jet flow, while $4\%$ at orthogonal angle. iii) The model was then applied to 2 culture ponds located at the Western coast of Korea. The measured and predicted currents for the ponds were compared using the regression analysis. Analysis of flow direction and speed showed correlation coefficients 0.8928 and 0.6782 in pond A, 0.8539 and 0.7071 in pond B, respectively. Hence, the model is concluded to accurately predict circulation driven by paddlewheel such that it can be a useful tool to provide pond management strategy relating to paddlewheel operation and water quality.

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Dynamics of Barrel-Shaped Young Supernova Remnants (항아리 형태 젊은 초신성 잔해의 동력학)

  • Choe, Seung-Urn;Jung, Hyun-Chul
    • Journal of the Korean earth science society
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    • v.23 no.4
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    • pp.357-368
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    • 2002
  • In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

An Experimental Study on Optimum Slanting Angle in Reticulated Root Piles Installation (그물식 뿌리말뚝의 최적 타설경사각에 관한 실험 연구)

  • 이승현;김병일
    • Geotechnical Engineering
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    • v.11 no.2
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    • pp.29-36
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    • 1995
  • Load testis are executed on model reticulated root piles (RRP) to figure out the optimum slanting angle in the piles installation. One set of model RRP consists of 8 slanting piles which are installed in circular patterns forming two concentric circles, each of which is made by 4 piles. Each pile which is a steel bar of 5m in diameter and 300mm in length is coated to become a pile of 6.5mm in diameter. The slanting angle of the model RRP varies from 0$^{\circ}$ to 20$^{\circ}$ Comparing ultimate bearing capacities of the model RRP of different installation angles, it is observed that the ultimate capacities of the RRP increase as the installation angle increases until 15$^{\circ}$, and the optimum slanting angle of the RRP is around 15$^{\circ}$ The ultimate bearing capacity of the 15$^{\circ}$-RRP is found to be 22% bigger than that of the vertical RRP and 120% bigger than that of the circular surface footing whose diameter is same with the circle formed by outer root piles'heads. However, it is noticed that when the slanting angle of the RRP is increased over 15$^{\circ}$, the ultimate capacity starts to be reduced. The ultimate capacity of 20$^{\circ}$-RRP is even smaller than that of the vertical RRP by as much as 5%. From the observation of the load settlement curve obtained during the RRP load tests, it is known that as the slanting angle gets bigger the load -settlement behavior becomes more ductile.

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Effects of Complex Probiotics and Antibiotics on Growth Performance and Meat Quality in Broilers (복합생균제와 항생제 급여가 육계의 생산성 및 육질에 미치는 영향)

  • Park, Sung-Hyun;Choi, Jung-Suk;Jung, Dong-Soon;Auh, Joong-Hyuck;Choi, Yang-Il
    • Food Science of Animal Resources
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    • v.30 no.3
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    • pp.504-511
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    • 2010
  • This study was undertaken to investigate the effects of feeding complex probiotics (Lactobacillus casei, Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus oryzae, Streptomyces griseus, $1.5{\times}10^{10}$ CFU/kg) and antibiotics (oxytetracycline (OTC), 110 ppm) on growth performance and meat quality characteristics of broiler chicks. In the experiment 1, 0.3% complex probiotics feeding level was chosen to be proper addition level due to better average daily gain (ADG), feed conversion (FC) and dressing percent (DP) results among 3 levels (0.1, 0.3 or 0.5%). In the experiment 2, 5 treatments (T1, no probiotics + no antibiotics; T2, probiotics 0.3% + no antibiotics; T3, probiotics 0.3% + antibiotics 50%; T4, probiotics 0.3% + antibiotics 100%; T5, no probiotics + antibiotics 100%) were investigated. In the growth performance of broilers, T5 (antibiotics 100% only) showed the highest (p<0.05) ADG and FC values while T1 (control) showed the worst growth performance. However, T3 (probiotics 0.3% + antibiotics 50%) showed higher ADG (p<0.05), FC (p<0.05) and DP (p>0.05) values compared to control. In the breast and leg meat quality, T3 showed similar pH, proximate composition, cooking loss and meat color values except shear force value compared to T5. Addition of 0.3% probiotics with 50% antibiotics (T3) tended to lower the blood cholesterol levels of broiler chicks and Escherichia coli or Salmonella counts in cecum microflora of broiler chicks compared to T5. In the residual antibiotics analysis, T3 contained 0.04 ppm of residual antibiotics in the breast meat while T4 or T5 contained 0.1 ppm of residual antibiotics and addition of 0.3% probiotics with 50% antibiotics in broiler diets could lower the residual antibiotics level to 40% in the meat. As a result, 0.3% probiotics addition with 50% antibiotics in the broiler diets could be recommended for the production of high quality broiler meat.

Manufacture of Spent Layer Chicken Meat Products by Natural Freeze-Drying during Winter (겨울철 자연 동결 건조에 의한 노계 육제품의 제조)

  • Lee, Sung-Ki;Kang, Sun-Moon;Lee, Ik-Sun;Seo, Dong-Kwan;Kwon, Il-Kyung;Pan, Jo-No;Kim, Hee-Ju;Ga, Cheon-Heung;Pak, Jae-In
    • Food Science of Animal Resources
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    • v.30 no.2
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    • pp.277-285
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    • 2010
  • The objective of this study was to manufacture spent layer chicken meat products by natural freeze-drying. The spent layers of chickens that were slaughtered at 80 wk were obtained from a local slaughter house and separated into two halves of carcasses. The samples were divided into the following groups: 1) control (non-curing), 2) curing, and 3) curing with 2% trehalose before drying. The cured meats were placed at $2^{\circ}C$ for 7 d and then transferred to a natural drying spot located in Injae City, Gangwondo, Korea. The experiment was conducted from January to March in 2008. The average temperature, RH, and wind speed were $-1.5^{\circ}C$, 63%, and 1.8 m/sec, respectively. The cured treatments showed higher pH, lower Aw and lower shear force value compared with the control. Based on the results of TBARS (2-thiobarbituric acid reactive substances) level and volatile basic nitrogen value, lipid oxidation and protein deterioration were inhibited in curing treatments during drying. Trehalose acted as a humectant because it maintained a lower water activity despite the relatively higher moisture content during drying. The polyunsaturated fatty acids content and sensory attributes were higher in cured treatments than in the control during drying. Most of the bacterial counts in the treated groups were lower by 2 Log CFU/g after 1 mon of drying, and Salmonella spp. and Listeria spp. were not found in any treatment. There was also no microbial safety problem associated with dried meat products. Based on the results of this experiment, dried meat products could be manufactured from precured spent layer chickens by natural freeze-drying during winter.