• Journal of Korean Society for Atmospheric Environment
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• v.32 no.2
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• pp.158-166
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• 2016

To characterize the features of particle apparent density, continuous measurements of particle number size distributions from optical particle sizer (OPS) and 24 hr integrated particle mass concentrations from filter based sampler were conducted at the National institute of environmental research NamBu Supersite (NNBS, $35.22^{\circ}N$, $126.84^{\circ}E$) in Gwangju for 16 days from Nov. 4 in 2014. Source apportionment model was carried out by applying Positive Matrix Factorization (PMF) to particle size distribution data. Three different distributions related to primary and secondary sources were investigated by the diurnal patterns of identified factors. Density estimated by gaussian model has been calculated as $1.69g/cm^3$ with 95% confidence bounds ($1.57{\sim}1.81g/cm^3$).

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.11
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• pp.2971-2980
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• 1995

A numerical study of fluid flow in driven cavity was carried out using singular finite element method. The driven cavity problem is known to have infinite velocity gradients as well as dual velocity conditions at the singular points. To overcome such difficulties, a finite element method with singular shape functions was used and a special technique was employed to allow multiple values of velocities at the singular points. Application of singular elements in the driven cavity problem has a significant influence on the stability of solution. It was found the singular elements gave a stable solution, especially, for the pressure distribution of the entire flow field by keeping up a large pressure at the singular points. In the existing solutions of driven cavity problem, most efforts were focused on the study of streamlines and vorticities, and pressure were seldom mentioned. In this study, however, more attention was given to the pressure distribution. Computations showed that pressure decreased very rapidly as the distance from the singular point increased. Also, the pressure distribution along the vertical walls showed a smoother transition with singular elements compared to those of conventional method. At the singular point toward the flow direction showed more pressure increase compared with the other side as Reynolds number increased.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.79-84
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• 2011

In general, a valve body of the automatic transmission(AT) is controlled by the clutch, the brake and lubricating oil flow in a hydraulic system and lubricant flow for each valve can be adjusted independently. To increase the lifetime of AT, the lubrication flow rate in a valve body for a 6 speed AT based parallel hybrid electric vehicle must be provided with proper oil distribution and control. In this study, we carried out several experiments without the inner parts of AT and with a AT assembly. The variation of the flow rate on oil temperature and pressure between an oil supply port and the outlets of the lubrication port was evaluated and analyzed. In the case of AT without the inner parts, it was evident that as the oil required for an operation of the clutch and brake was discharged from the outlet port, the flow rate from each lubrication port is decreased. However, the flow rate of the AT assembly was slightly increased. In addition, the lubrication flow rate was increased with increasing the oil temperature, and also it was reduced with increasing the oil pressure. Details of the resulting data are discussed.

• Magazine of the Korea Concrete Institute
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• v.3 no.4
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• pp.97-106
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• 1991

The object of this study is to propose the Flexural moment-curvature relationship based on the bond property between concrete and steel for noncracking zone, to evaluate the flexural displacement of reinforced concrete member. The bond-slip relationship and the strain hardening effect of steel were taken into consideration in order to evaluate the spacing of the cracks and the curvature distribution. Calculated curvature distribution along the longitudinal axis was transformed into equivalent curvature distribution. The flexural displacement was calculated by means of double integrals of the equivalent curvature. Furthermore, 34 beams were tested in order to verify the proposed procedure Calculated values agreed well with the experimental data, and so it is pointed out that proposed method is widely acceptable for the practical evaluation of flexural displacement of reinforced concrete member.

• Journal of Korean Medicine for Obesity Research
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• v.8 no.2
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• pp.25-35
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• 2008

Objectives This study was performed to find out the characters about distribution of abdominal fat(especially superficial and deep subcutaneous fat) in obese premenopausal Korean women. Methods 39 obese premenopausal women were recruited in 2008. Anthropometry and body impedance analysis have been done and abdominal fat distribution had been assessed by computed tomography scan at the level of L4-5. Blood test and questionnaires about depression, eating attitude and physical activity were underwent. Result Abdominal total fat area, subcutaneous fat area including superficial and deep were significantly correlated with anthropometry and BIA result while visceral fat was correlated only with age and waist circumference. In blood profile, only visceral fat area was correlated with HDL cholesterol and triglyceride. And there were no correlation among questionnaires and abdominal fat. There were no difference between superficial and deep subcutaneous fat. Conclusion Abdominal subcutaneous fat including superficial and deep did not have any correlation with heart risk factor. superficial and deep subcutaneous fat had no differences with each other and they did not show any correlation with visceral fat in obese perimenopausal Korean women.

• Journal of Power Electronics
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• v.18 no.2
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• pp.573-587
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• 2018

Recently evolved power electronics' based domestic/residential appliances have begun to behave as single phase non-linear loads. Performing as voltage/current harmonic sources, those loads when connected to a three phase distribution network contaminate the line current with harmonics in addition to creating a neutral wire current increase. In this paper, an enhanced performance three phase four leg shunt active power filter (SAPF) controller is presented as a solution for this problem. The presented control strategy incorporates a hybrid predictive fuzzy-logic based technique. The predictive part is responsible for the SAPF compensating current generation while the DC-link voltage control is performed by a fuzzy logic technique. Simulations at various loading conditions are carried out to validate the effectiveness of the proposed technique. In addition, an experimental test rig is implemented for practical validation of the of the enhanced performance of the proposed technique.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.43-44
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• 2006

Generally almost all fatigue crack growth is affected by model. For this reason a study on model has concentrated in the field of fracture mechanics. However the fatigue crack initiation and growth in machines and structures usually occur in mixed mode loading. If there is any relationship between the cause of fracture in mixed mode loading and fracture surface, fracture surface pattern will be the main mean explaining reasons of fatigue fracture and obtaining further information about fracture process. In this paper four point shear-fatigue test with Aluminum alloy Al 5083-O is carried out from this prospect and then the mixed mode distribution of fracture surface is examined from the result after identifying the generation of fatigue crack surface pattern. It was found from the experimental results that the fatigue crack surface pattern and the fatigue crack shear direction are remarkably consistent. Furthermore It is possible that the analysis of distribution of mixed mode through the fatigue crack surface pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.233-237
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• 1976

This study was carried out to evaluate the distribution of Vibrio parahaemolyticus and Vibrio alginolyticus in sea water, mud, oyster (Crassostrea gigas) and sea mussel (Mytilus edulis) collected from the coast of Chung-mu during the period from July 1975 to September 1976. Fifty one strains of V. parahaemolyticus and 160 strains of V.. alginolyticus were isolated from 420 samples. The distribution varied by month showing the highest in July through September The isolation ratio of V. parahaemolyticus was $28\%$ for mud, $24\%$ for sea water, $5\%$ for sea mussel and $4.2\%$ for oyster. The morphological, physiological and biochemical characteristics of 211 isolated strains were coincided with those of the typical V. parahaemolyticus and V. alginolyticus.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.519-527
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• 1996

Most operation related to the application granular agrochemicals in korea are manual and labour consuming. As a multipurpose granular applicator, a pneumatic granular applicator that can be attached to conventional ride -on machines for paddy field was designed in this study. Experiments and simulations were carried out for determine in the design factors with one fertilizer (DongBu 21-17-17) and one pesticide (SamKong Ivi). The maximum terminal velocity of granular chemicals was estimated as 14.2m/s. A better distribution pattern was obtained at the diffuser having only deflectors without dividing guides. The diffuser spacing 1.0m for the fertilizer and the diffuser spacing 0.8m for the pesticide at the boom height over 0.80m were acceptable for the uniform distribution. In the case that the forward speed of ride-on machines was 0.7m/s, the groove opening and the roller speed of the selected metering device were13mm -15mm at 2 rps for the fertilizer, and 9 mm-11mm at 0.25rps or the pesticide. This study suggested a method of developing a pneumatic applicator for granular agrochemicals.

• The Journal of Industrial Distribution & Business
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• v.10 no.7
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• pp.17-27
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• 2019

Purpose - In this study, previous CSR researches was reviewed to help understand the CSR effects, and offer suggestions for future research directions. Research design, data, and methodology - To achieve the purpose of this study, previous CSR effects related researches were reviewed based on stakeholder perspectives. Results - After reviewing, some limitations were found. First, most of the CSR related studies in the management area have focused on CSR effects on individual stakeholders such as the shareholder, the employee, and the consumer. Second, it was difficult to find studies on the management aspect of CSR from both an effective and efficient perspective. Conclusions - To overcome these limitations of previous studies, several studies need to be conducted in the future. First, CSR research must be expanded into B-to-B businesses. Few studies try to figure out the effect of CSR on B-to-B businesses but only suggest the effect of CSR on B-to-B business conceptually. Therefore, empirical study needs to be conducted about CSR to show business performance in the B-to-B market. Second, the process of CSR must be developed on how to improve CSRs' effectiveness and efficiency. Finally, a relationship between a company and individual stakeholders needs to be revised using stakeholders' multiple identities.