• Steel and Composite Structures
• /
• v.18 no.2
• /
• pp.305-324
• /
• 2015

In this study, two common types of laterally supported castellated beams are considered as design problems: beams with hexagonal openings and beams with circular openings. The main goal of manufacturing these beams is to increase the moment of inertia and section modulus, which results in greater strength and rigidity. These types of open-web beams have found widespread use, primarily in buildings, because of great savings in materials and construction costs. Hence, the minimum cost is taken as the design objective function and the Colliding Bodies Optimization (CBO) method is utilized for obtaining the solution of the design problem. The design methods used in this study are consistent with BS5950 Part 1 and Part 3, and Euro Code 3. A number of design examples are considered to optimize by CBO algorithm. Comparison of the optimal solution of the CBO algorithm with those of the Enhanced Charged System Search (ECSS) method demonstrate the capability of CBO in solving the present type of design problem. It is also observed that optimization results obtained by the CBO algorithm for three design examples have less cost in comparison to the results of the ECSS algorithm. From the results obtained in this paper, it can be concluded that the use of beam with hexagonal opening requires smaller amount of steel material and it is superior to the cellular beam from the cost point of view.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.45 no.1
• /
• pp.75-82
• /
• 2013

The traditional Hanji-making was confronted with lots of industrial disadvantages and economic problems, due to the original hand-made process. Recently, the studies on the automation of overall Hanji manufacturing process is carried out by applying the commercial chemical pulping method in order to expand industrial application or efficiency of non-wood fibrous materials. However, the application of commercial pulping methods to the bast tissues of paper mulberry leads to the chemical and mechanical deterioration of cellulosic fibers. In this study, the optimal cooking method using the bast parts of paper mulberry produced by an auto-scraping device was applied to minimize the damage of fiber strength for the paper yarn manufacture. The pre-steaming treatment and alkaline pulping systems were evaluated in removal efficiency of lignin and pectin materials within the bast tissue of paper mulberry. With the application of pre-steaming treatment and 2 stage pulping system using potassium carbonate and then sodium hydroxide, kappa values were decreased two times more in lignin removal than the single stage of pulping method. It was also identified from SEM images and ATR-FTIR spectra that the pectin components within cellular structure of bast tissue were easily removed and the debarked bast parts by a auto-scraping device were easily defiberized by 2-stage pulping sequence using potassium carbonate/sodium hydroxide pulping system.

• Analytical Science and Technology
• /
• v.27 no.5
• /
• pp.248-253
• /
• 2014

This study aimed to evaluate the effects of exposure to manganese (Mn) and lead (Pb) on immune system. The subjects were 42 male workers, among whom 13 office workers (Group I) had never been occupationally exposed to heavy metals, 21 were worked in manufacturing factories (Group II) and 8 were welders (Group III). The mean blood Mn and Pb level by groups were significantly different. The numbers of CD19+ and total lymphocytes in Group I were significantly higher than those in other groups, but no significant differences were found in other T lymphocytes subpopulation. Mn and Pb concentrations showed negative correlation with T lymphocytes subpopulation, but Mn concentrations were statistical significances with T lymphocytes subpoplation except CD4+CD45RO+ and natural killer cell. Pb concentration was only statistical significance with total lymphocytes. Our results suggest that occupationally exposed to Mn and Pb can affect the cellular immune response.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.202-202
• /
• 2011

The research of 3-dimensional (3-D) scaffold for tissue engineering has been widely investigated as the importance of the 3-D scaffold increased. 3-D scaffold is needed to support for cells to proliferate and maintain their biological functions. Furthermore, its architecture defines the shape of the new bone and cartilage growth. Polycaprolactone (PCL) has been one of the most promising materials for fabricating 3-D scaffold owing to its excellent mechanical property and biocompatibility. However, there are practical problems for using it, in vitro and in vivo; extracellular matrix components and nutrients cannot penetrate into the inner space of scaffold, due to its hydrophobic property, and thus cell seeding and attachment onto the inner surface remain as a challenge. Thus, the surface modification strategy of 3-D PCL scaffold is prerequisite for successful tissue engineering. Herein, we utilized a mussel-inspired approach for surface modification of 3-D PCL scaffold. Modification of 3-D PCL scaffolds was carried out by simple immersion of scaffolds into the dopamine solution and stimulated body fluid, and as a result, hydroxyapatite-immobilized 3-D PCL scaffolds were obtained. After surface modification, the wettability of 3-D PCL scaffold was considerably changed, and infiltration of the pre-osteoblastic cells into the 3-D scaffold followed by the attachment onto the surface was successfully achieved.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.2430-2434
• /
• 2005

Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

• Applied Biological Chemistry
• /
• v.48 no.4
• /
• pp.382-387
• /
• 2005

The aim of this study was to identify binding properties of germanium (Ge) in Germanium-fortified Yeast using optimum manufacturing process. The ratio of yeast cell and germanium solution was 1 : 0.5 (50%), and pH 6.5, $35^{\circ}C$ and 20 h during fermentation, and Germanium-fortified Yeast produced. In results of the XRD, NMR and FT-IR analysis, it was different adding inorganic Ge $(GeO_2)$ during fermentation process from transformed into germanium in Germanium-fortified Yeast. And germanium concentration was not shown any difference before and after in the dialysis test with SGF (simulated gastric fluids). Therefore, Germanium-fortified Yeast of Geranti made by using biosynthetic technology was considered that transformed into organic properties during fermentation process. And, this result showed that Germanium-fortified Yeast was not dissociated under SGF (simulated gastric fluids) condition because of its structural binding safety. Thus, Germanium-fortified Yeast was transformed into organic germanium during biosynthetic cultivation. It is expected that this Germanium-fortified Yeast can be applied as a new dietary functional materials for cellular immunity, recovery of injured cells and immune system, and possible anticancer activities by activation immune cells like macrophage.