• 한국공작기계학회논문집
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• 제17권1호
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• pp.35-42
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• 2008

By the reason of increased demand of high productivity and quality, the manufacturer have an effort in many directions of a machine tool industries. Among there, we proposed method of decreasing displacement in MC(machining center). In other words, Quality related with vibration of a tool cutting products. For decreasing it, improved by optimizing a shape of the column-part and acceleration curves of motors. In this paper we could find design factors has much influence on decreasing the displacement using the DOE(Design of Experiments) and optimized the level of the factors using $ADAMS^{(R)}$ and $MINITAB.^{(R)}$ And we suggest optimized a acceleration curve using $Matlab^{(R)}$.

• 한국환경과학회지
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• 제4권3호
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• pp.295-301
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• 1995

Continuous deodorization of malodorous sulfur compounds by Thiobaillus neapolitanusts R-10 immobilized onto a polypropylene pellet was studied using a column reactor at 30$^{\circ}$C. The maximum amounts of immobilized cells was 5.3 gall polypropylene with 5$\times$7.5mm in pellet size, and the amounts of immobilized cells in the higher part of the column was as twice as in the lower part. The optimum pH and temperature for removal of dimethyl sulfide were 6.0 and 30$^{\circ}$C, respectively. When 5-20 ${mu}ell$/l of hydrogen sulfide and methylmercaptan were employed 98% of removal efficiency were achieved. In contrast, lower concentrations of dimethyl sulfide and dimethyldisulfide should be supplied to meet satisfactory deodorization efficiency. The immobilized cell column was successfully operated for the deodorization of mixture of sulfur compounds over 15 days without significant loss of initial activity achieving high efficiency.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.697-702
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• 2006

This paper deals with the free vibrations of immersed columns with soft base. The support condition of the column is represented by using a translational spring and a rotational spring. The eccentricity and rotatory inertia of the concentrated mass at the top are taken into account. In the governing equation for the free vibration of column, the density of immersed part was modified to account for the added fluid mass. The governing differential equations are solved numerically using the corresponding boundary conditions. Numerical results are presented to show the effects on the natural frequencies of non-dimensional system parameters: the mass density ratio of fluid to column, the ratio of fluid depth to span length, the ratio of tip mass to total column mass, the dimensionless mass moment of inertia, the eccentricity, the translation spring parameter, and the rotational spring parameter.

• 건축역사연구
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• 제3권1호
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• pp.45-55
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• 1994

This study deals with the method of constructing and repairing column, important element of traditional wooden building. Column should have long-lasting strength and resistance to decay and vermin because it is more important in role of structure than in that of ornament. And the rotten or the split part of wooden column should be repaired regularly or irregularly. First of all, this study treats of general character related to the life length and strength of wood. Then it describes the technical method of choosing proper wood for column and that of carpentering, painting, and mending wooden column.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.9-28
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• 2000

The purpose of this article, the first part of series, is to describe the general theory applicable to various chromatographic procedures. History of chromatography, separation of matters, classification of chromatography, underlying principles of separation in chromatography, covering resolution, column efficiency, column selectivity, and capacity factor, movement of solute in chromatographic phase, including elution development, displacement development, and frontal analysis, were discussed. Mathematical description of plate theory and thermodynamic viewpoint of retention were emphasized.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.144-147
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• 2007

Internally Confined Hollow-Concrete Filled Tube(ICH-CFT) column which has two tubes on both side of concrete, inner tube and outer tube perform great seismic abilities, ductility and absorption of energy, by the tubes and the hollow part. So this study does qualitative analysis about seismic capacities depending on parameters - diameter of column, hollow ratio, thickness of tubes - by moment-curvature analysis.

• Steel and Composite Structures
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• 제34권6호
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• pp.803-818
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• 2020

Semi-rigid connections with blind bolts could solve the difficulty that traditional high strength bolts were unavailable to splice a steel/composite beam to a closed section column. However, insufficient investigations have focused on the performance of semi-rigid connection to square concrete filled double-skin steel tubular (CFDST) columns. In this paper, a component model was developed to evaluate the mechanical behavior of semi-rigid composite connections to CFDST columns considering the stiffness and strength of column face in compression and column web in shear which were determined by the load transfer mechanism and superstition method. Then, experimental investigations on blind bolted composite joints to square CFDST columns were conducted to validate the accuracy of the component model. Dominant failure modes of the connections were analyzed and this type of joint behaved semi-rigid manner. More importantly, strain responses of CFDST column web and tubes verified that stiffness and strength of column face in compression and column web in shear significantly affected the connection mechanical behavior owing to the hollow part of the cross-section for CFDST column. The experimental and analytical results showed that the CFDST column to steel-concrete composite beam semi-rigid joints could be employed for the assembled structures in high intensity seismic regions.

• Environmental Engineering Research
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• 제20권2호
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• pp.175-180
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• 2015

This research focused on the solid and nitrate removal efficiency in a solid digestion-denitrification column. The 20 L up-flow column consisted of 18 L acrylic column with 2 L down-comer inlet tube located in the middle. In the first part, the wastewater with high suspended solids from the Tilapia fish tank was applied into the sedimentation unit at 5 variable flow rates i.e., 11.25, 25.71, 60, 105.88 and 360 L/h. The results indicated that the flow rate of 11.25 L/h (0.57 m/h) gave the highest solid removal efficiency of $72.72%{\pm}8.24%$. However, the total suspended solids removal was highest at 360 L/h (18.13 m/h). In the second part, methanol was added as an external organic carbon source for denitrification process in a hybrid column containing settled solids. The COD:N ratios of 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1 were investigated and compared with control without methanol addition. This experiment was operated at the HRT of 1 h with 450 L wastewater from recirculating aquaculture pond containing 100 mg-N/L sodium nitrate. The results indicated that the COD:N ratio of 3:1 gave the highest nitrate removal efficiency of $33.32%{\pm}21.18%$ with the denitrification rate of 5,102.88 mg-N/day.

• Steel and Composite Structures
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• 제6권6호
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• pp.493-512
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• 2006

The present paper summarizes the experimental research carried out at the "Politehnica" University of Timisoara, Romania, with the scope of investigating the influence of different column web stiffening solutions on the performance of beam-to-column joints of Moment Resisting Steel Frames. The response parameters, such as resistance, rigidity and ductility were examined. Five different types of panel web stiffening were compared with regard to a reference test. A quasi-linear relationship between the moment capacity and the total shear area of the web panel was observed from the experimental tests while the initial rigidity increased non-proportionally with the same area. Comparisons are presented of the experimental tests with the mathematical model developed by Krawinkler and with the model stipulated in Eurocode 3 Part 1.8. These comparisons showed a generally good agreement in the case of moment capacity, while the computed rigidities were always greater than the experimental rigidities.

• 콘크리트학회논문집
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• 제12권4호
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• pp.113-119
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• 2000

The R/C flat plate system provides architectural flexibility, clear space, reduced building height, simple formwork, which consequently enhance constructibility. One of the serious problems in the flat plate system is brittle punching shear failure due to transfer of shear force and unbalanced moments in column-slab joint. Recently, the flat plate system accompanied with shear walls to resist the lateral loads is applied to high-rise buidings. Although the flat plate system is not considered in design as part of the lateral load-resisting system, it is required that this system keeps the ductile behavior for the lateral displacement of the building. However, it is unclear whether the column-slab joint possesses ductility enough to survive the lateral deformation. The objective of this paper is to investigate the major parameters that influence the ductility of R/C flat plate system by examining the existing experiments on column-slab joint. The effects of gravity load and shear reinforcement on the ductility of the flat plate system are presented.