• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.157-164
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• 2012

The design strategy of the multi-functional structure is that the electrical components and the circuits are directly put on their supporting structural panel in which the radiation shields and the thermal control functions are integrated. Applying the multi-functional structure reduces the total mass and size of the space system and makes it possible to lower launch cost. In present study the performance of thermal radiation for six types of multi-functional structure are investigated by the numerical method. The effect of the rib configuration on heat transfer for the multi-functional-structure is not important alone but is meaningful considering with the structural stiffness, difficulty of manufacturing and mass increase. In heat spreading point of view, the thickness of the outer conductive layer is important rather than the rib configuration and the trade-off study with the mass and thickness is required for optimum design.

• The KSFM Journal of Fluid Machinery
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• v.15 no.4
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• pp.19-26
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• 2012

In this paper, a parametric study on ribs which are installed in an equilateral triangular internal cooling channel is presented. The numerical analysis of the flow structure and heat transfer characteristics is performed using three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. The numerical results are obtained at Reynolds number, 20,000. The parametric study is performed for the parameters, the angle of a rib, rib pitch-to-hydraulic diameter ratio, rib width-to-hydraulic diameter ratio, and rib height-to-hydraulic diameter ratio. The computational results are validated with the experimental data for area-averaged Nusselt number.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.4
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• pp.337-341
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• 2006

The tensile properties of Poly(trimethylene terephthalate, PTT) $1{\times}1Rib$ knitted fabrics were experimentally studies, and the specimens has $1{\times}1$ rib stitched structure which are weft knitted fabrics with various lengths of loop. The $1{\times}1$ rib weft knitted fabric showed larger tensile linearity, tensile energy and tensile resilience in the direction of courses. The tensile properties increased with increasing the loop density in all directions, and perfectly increased with the course directions than the wale directions.

• Korean Journal of Microbiology
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• v.12 no.3
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• pp.101-114
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• 1974

The fine structure of HeLa cells treated with several mycotoxin-producing fungi (Aspergillus flavus ATCC 15517, Aspergillus parastiticus RIB 1037, Penicillium toxicarium RIB 4002, Penicillium cirinum SWU)238, Penicillium islandicum IFO 5235, Penicillium tadum IFO 5787 and Pencillium brunneum RIB 1172) has been examined and some details have been descried. The normal HeLa cell have numerous microvilli, large ovoid nucleus, pleomorphic mitochondria, electron-dense body, Golgi complex, mid-body and endoplasmic reticulum etc. Certain specific structural changes induced by culture filtrates of several mycotoxin-producing fungi have been noted. These alterations induced disappearance of Golgi complex, rER vacuolization, nucleolus attachment to the nuclear envelope nad appearance of certain vacuoles. There were not any changes by the treatment of culture filtrates of non-toxic fungi and only cell debris of some specimens can be observed by the injury of culture filtrates. The experimental animals treated with mycotoxin-producing fungi (Aspergillus flavus ATCC 15517, Aspergillus parasilicus RIB 1037, Penicillum citrinum SWU 238, Penicillium toxicarium RIB 4002, and Penicillium islandicum IFO 5235) were mal cells treated with culture filtrates.

• Transactions of Materials Processing
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• v.26 no.6
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• pp.372-377
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• 2017

In this paper, an effective design procedure was proposed to design the rib of die structure for auto-body member with ultra-high strength steel (UHSS) having ultimate tensile strength (UTS) of 1.5 GPa. From analysis results of the die structure, structural safety of the die was evaluated with information such as displacement and von-Mises stress. It was concluded that the casting part could be designed in order to reduce tool deformation. A design guideline of the die structure was proposed, especially for the rib structure in the casting part with an optimization scheme and local reinforcement concept. Simulation result following the design guideline fully explained that stability of the tool structure could be obtained simultaneously with weight minimization.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.462-467
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• 2007

From the research which it sees verification of the whole interpretation and local interpretation of the durability steel deck bridge a static test and it produces the test body which it sells with character and it executes smallness pul lek detailed interpretation it leads and the appropriate characteristic of smallness pul lek detailed interpretation and to sleep a nominal stress price and it compares it judges it does. The stress quality from each structure region which it follows in load stock location it analyzes and from the hazard which evaluates, the objective region the length rib and the bottom grater weld zone, the length rib and width rib connection department and the width rib with the father it divided. It investigated the stress distribution of the test body from these objective location, FEM interpretation it led and the conduct against each structure state tax it analyzed. General conduct the load stock location the floor plate is located in the center with interpretation price together symmetry characteristic to seem, it cannot be like that it cannot there is one actual test price. Like this reason the length rib and width rib connection actually production even production characteristic security it is a day when it is impossible with the curvature junction department which it blows, it follows in examination body deferment condition and form feed with the fact that it is visible a big difference even with error of some it becomes. Consequently for a data and the research which are more accurate it is judged with the fact that the effort which is prudent will be necessary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.111-114
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• 2005

Experimental and numerical studies were carried out in order to investigate the processability and the transcriptability of the injection molding of micro structures. For this purpose, we designed a mold insert having micro rib patterns on a relatively thick base part. Mold insert has a base of 2mm thickness, and has nine micro ribs on that base plate. Width and height of the rib are $300{\mu}m\;and\;1200{\mu}m$, respectively. We found a phenomenon similar to 'race tracking', due to 'hesitation' in the micro ribs. As the melt flows, it starts to cool down and melt front located in the ribs near the gate cannot penetrate further because the flow resistance is large in that almost frozen portion. When the base is totally filled, the melt front away from the gate is not frozen yet. Therefore, it flows back to the gate direction through the ribs. Consequently, transcriptability of the rib far from the gate is better. We also verified this phenomenon via numerical simulation. We further investigated the effects of processing conditions, such as flow rate, packing time, packing pressure, wall temperature and melt temperature, on the transcriptability. The most dominant factor that affects the flow pattern and the transcriptability of the micro rib is flow rate. High flow rate and high melt temperature enhance the transcriptability of micro rib structure. High packing time and high packing pressure result in insignificant dimensional variations of the rib. Numerical simulation also confirms that low flow rate causes a short shot of micro ribs and high wall temperature helps the filling of the micro ribs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.138-147
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• 2011

The objective of this study which it sees direct shear stress and comparative analysis of flexural shear stress leads and it is a shear stress analysis which it follows in load direction of the structure which uses Perfobond Rib shear connectors. To analyze direct shear stress, five Perfobond Rib shear connect experiments were fabricated with five variables and conducted Push-out Tests. After experiments, mechanism of Perfobond Rib shear connector was examined and direct shear formula was proposed based on primary factors which influence direct shear stress. Also, for the analysis of flexural shear steel-concrete composite slab specimens were fabricated and static flexural test. Based on the static flexural test it analyzed the flexural behavior and the flexural shear stress it calculated. Direct shear stress and EN 1994-1-1 to lead and be calculated, it compared the flexural shear stress and it analyzed in about the shear resistance stress which it follows in load direction.

• Composites Research
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• v.31 no.4
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• pp.161-170
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• 2018

Cylindrical composite lattice structures are manufactured by filament winding process. The fiber volume fraction non-uniformity and resin rich layers that can occur in the manufacturing process affect the stiffness and strength of the structure. Through the cross-section examination of the hoop and helical ribs, which are major elements of the composite lattice structure, we observed the fiber volume fraction non-uniformity and resin rich layers. Based on the results of the cross-section examination, the stiffness of the ribs was analyzed through the experimental and theoretical approaches. The results show that the fiber volume fraction non-uniformity and resin rich layers have an obvious influence on the rib stiffness of composite lattice structure.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.6
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• pp.502-509
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• 2003

This paper describes a detailed experimental investigation of heat transfer in a reciprocating rectangular channel fitted with rib structures with particular reference to the design of a piston for marine propulsive diesel engine. The parametric test matrix involves Reynolds number, reciprocating frequency, and reciprocating radius, respectively in the ranges, 1,000～6,000, 1.7～2.5 Hz, and 7～15 cm with four different rib arrangements. The rib arrangements have considerable influences on the heat transfer in the reciprocating channel due to the modified vortex flow structure. The experimental data confirm that the increases in the heat transfer can be seen in order of Case (b), Case (c), Case (d), and Case (a).