• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.140-146
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• 2002

The tulip-inversion of flames in half-open tubes was investigated experimentally. Experiments was carried out in tubes with various shapes. The image of a flame propagation were pictured by HICCD(High speed intensified CCD) and the dynamic pressure of tubes was measured by a piezo pressure sensor. By analyzing the images of the flame propagation, we found the time and the distance for the occurrence of tulip-inversion. Regardless of the shapes of tubes, time of tulip-inversion are similar and inversely proportional to the burning velocity. But distances have different tendency. In a straight tube, the distance of tulip-inversion increases when the burning velocity increases. But in a converging tube, the distance of tulip-inversion decreases when a burning velocity increases. And the distance of tulip-inversion in a converging tube is much smaller than the distance of tulip-inversion in a straight tube. These results are caused by the deceleration of a flame when the diameter of a hole in open-side of a tube is small. The deceleration causes little effect on the time of tulip-inversion.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.4
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• pp.91-100
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• 2015

The purpose of this study is to analyze the style of check dresses shown in collections from 2011 to 2014 and to extract main expressional words for the development of semantic differential scales of visual images according to the change in silhouette of block check dresses. The results of this study are as follows: 1) 120 check dresses shown in collections were composed of 57 straight silhouette dresses, 38 fitted silhouette dresses, 23 hourglass silhouette dresses, 1 barrel silhouette dress, and 1 atypical silhouette dress. And check pattern mostly used in the current collections a square pattern of block check, tartan check that is a Scotch traditional lattice pattern, a small lattice pattern of gingham check, over check that other check patterns are arranged on check pattern, star-shaped hound tooth check, glen check mixing small pattern and big pattern. The visual image for check dress differs according to changes in the check pattern and silhouette of the dress. 2) Main expressional words of visual images for block check dresses differ greatly depending on the silhouette of dresses. The visual images are ranked in the order of 'graphic', 'simple', 'hard', 'modern' for straight silhouette of block check dresses. The words of 'lively', 'girlish', 'feminine', 'cute' are ranked for hourglass silhouette of block check dresses. And the words of 'confident', 'feminine', 'modern' are marked down for fitted silhouette of block check dresses.

• Advances in Computational Design
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• v.6 no.1
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• pp.15-30
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• 2021

With improvement in innovative manufacturing technologies, it became possible to fabricate any complex shaped structural design for practical applications. This allows for the fabrication of curvilinearly stiffened pressure vessels and pipes. Compared to straight stiffeners, curvilinear stiffeners have shown to have better structural performance and weight savings under certain loading conditions. In this paper, an optimization framework for designing curvilinearly stiffened composite pressure vessels and pipes is presented. NURBS are utilized to define curvilinear stiffeners over the surface of the pipe. An integrated tool using Python, Rhinoceros 3D, MSC.PATRAN and MSC.NASTRAN is implemented for performing the optimization. Rhinoceros 3D is used for creating the geometry, which later is exported to MSC.PATRAN for finite element model generation. Finally, MSC.NASTRAN is used for structural analysis. A Bi-Level Programming (BLP) optimization technique, consisting of Particle Swarm Optimization (PSO) and Gradient-Based Optimization (GBO), is used to find optimal locations of stiffeners, geometric dimensions for stiffener cross-sections and layer thickness for the composite skin. A cylindrical pipe stiffened by orthogonal and curvilinear stiffeners under torsional and bending load cases is studied. It is seen that curvilinear stiffeners can lead to a potential 10.8% weight saving in the structure as compared to the case of using straight stiffeners.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.207-212
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• 2019

Non-aqueous solvents (NASs) are generally known to be barely miscible, and reactive with polar compounds, such as water. However, water can interact with some NASs, which can be used as a new means for water recovery from saline water. This study explored the fate of water and salt in NAS, when saline water is mixed with NAS. Three amine solvents were selected as NAS. They had the same molecular formula, but were differentiated by their molecular structures, as follows: 1) NAS 'A' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain, 2) NAS 'B' with symmetrical structure and having the hydrophilic group (NH) at the middle of the straight carbon chain, 3) NAS 'C' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain but possessing a hydrophobic ethyl branch in the middle of the structure. In batch experiments, 0.5 M NaCl water was blended with NASs, and then water and salt content in the NAS were individually measured. Water absorption efficiencies by NAS 'B' and 'C' were 3.8 and 10.7%, respectively. However, salt rejection efficiency was 98.9% and 58.2%, respectively. NAS 'A' exhibited a higher water absorption efficiency of 35.6%, despite a worse salt rejection efficiency of 24.7%. Molecular dynamic (MD) simulation showed the different interactions of water and salts with each NAS. NAS 'A' formed lattice structured clusters, with the hydrophilic group located outside, and captured a large numbers of water molecules, together with salt ions, inside the cluster pockets. NAS 'B' formed a planar-shaped cluster, where only some water molecules, but no salt ions, migrated to the NAS cluster. NAS 'C', with an ethyl group branch, formed a cluster shaped similarly to that of 'B'; however, the boundary surface of the cluster looked higher than that of 'C', due to the branch structure in solvent. The MD simulation was helpful for understanding the experimental results for water absorption and salt rejection, by demonstrating the various interactions between water molecules and the salts, with the different NAS types.

• Steel and Composite Structures
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• v.47 no.1
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• pp.51-69
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• 2023

In tied-arch bridges, a properly designed connection between the arch and the deck may become crucial, since the forces in the structure may be significantly reduced. This implies substantial material savings and, consequently, cheaper constructions. The introduction of the Nielsen cable arrangement (composed of V-shaped inclined hangers) in the last century was a milestone because it was able to reduce deflections and bending moments both in the arch and in the deck. So far, the Nielsen cable arrangement has proven to be successful in traditional vertical arch bridges. However, despite its advantages, it has not been widely applied to spatial arch bridges. Thus, this article analyses the difference between the structural behavior of spatial arch bridges with Nielsen-type cable arrangements with respect to those with classical vertical hanger configurations. The main goal is to verify whether the known effectiveness of the Nielsen cable arrangement for classical arch bridges is still preserved when applied to spatial arch bridges. In order to achieve this objective, and as the first part of our study, a set of different all-steel bridges composed of vertical and inclined arches with straight decks have been compared for both cable arrangements. As a major conclusion, for planar vertical arch bridges, the Nielsen-type cable arrangement is always the most effective. In addition, it also seems that, for spatial arch bridges composed of a straight deck and an inclined arch, it still keeps most of its effectiveness as long as the arch is moderately inclined.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.213-219
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• 2001

In this paper, particle velocity of slurry flow, a kind of solid-particle two phase flow, was measured by using a particle tracking velocimetry. Particles are modeled by sphere-shaped glass whose diameters are 3mm, 5mm, and 7mm At first, a particle which is falling in the water is captured and analyzed to give their free falling velocity. The falling velocity was very high up to about 4m/sec in the air, which needs special algorithm for the accurate measurement. For the upwelling slurry flow in the straight duct, there are some noises caused by cavity. However, the effect was so small that it does not affect the measurement of large particles. From the preliminary study of applying the PTV to measurement of particle movement in slurry flow, we could find out the optimum value of parameters: threshold value., searching area radius and correlation area size.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.250-255
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• 2008

Springs are widely utilized in machine element. To find out stiffness of frustum-shaped coil spring, the space beam theory using the finite element method is adopted in this paper. In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. To find out load vector of coil spring subjected to distributed compression. principle of virtual work is adapted. And this theory was programming using MATLAB software. To compare FEM using MATLAB software was applied MSC. Nastran software. The geometry model for MSC. Patran was produced by 3-D design modeling software. Finite element model was produced by MSC. Patran. Finite element was applied tetra (CTETRA) having 10 node. The analysis results of the MATLAB and MSC. Nastran are fairly well agreed with those of various experiments. Using MATLAB program proposed in this paper and MSC. Nastran, spring constants and stresses can be predicted by input of few factors.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.113-122
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• 2007

Houses in Jeju city are divided into separated types and combination types of household affairs space. Other special types are separated-kitchen type. Separated household affairs space type is mostly built. Separated household affairs space type were sitting room + Gopang separate type and separate sitting room type. Combination household affairs space type made from sitting room, kitchen, Gopang and Chabang(Dinning room) put together as space differentiation, also into classes sitting room + kitchen + Gopang + Chabang type, sitting room + kitchen + Chabang type, sitting room + kitchen + Gopang, sitting room + kitchen type by combination household cares space type. Separated-kitchen type was one of the special type from separated-kitchen type of traditional housing, and type with continuous. Houses in Jeju city were 3 kan type and 4 kan type. 4kan type was mostly built. ㅡ shape is kept as plan shaped of straight shape, and roof shape is showed as ㅡ shape gathering roof. ㅡ shape + part projection type talls part projecting type as happened in Gopang, and Chabang. Roof is gathering roof, and when it is showed ㄱ shape by Gopang, Chabang, and kitchen are projected. ㅡ shape + total projection shape is one of the room become totally projected by Gopang and Chabang, can be happen with small room or kitchen, and roof as gathering roof shaped with ㅡ shape, ㄱ shape, ㄷ shape, unsystematic ㄹ shape, and various shapes.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.56-64
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• 1996

A large amount of papers about the cubic-to-tetragonal phase transition the ferroelectric domain structures of the BaTiO3 were already reported but there exist still some needs to observe the domain behaviors directly. In this study the domain structures of the tinned plates prepared from ta single crystal grown by the TSSG technique were observed using a polarizing microscope TE and X-ray topography. The spatial relation be-tween the orientation states of domains was investigated and the effects of external stresses and electric fields on the behaviors of ferroelectric and ferroelastic domains were studied. All the 90$^{\circ}$walls cut off in the crystal are the wedge shaped lamellar domains and all the straight boundaries in the observed domain patte군 can be interpreted as the head-to-tail 90$^{\circ}$walls. The irregular overlapped boundaries commonly observed by using a polarizing microscope and X-ray topography are complex combinations of well-known 90$^{\circ}$walls and are domain walls were predominant and were stabilized after surface polishing. In the paraelectric phase region the domain walls vanished but the residual surface strain patterns could be seen at the same positions of the stabilized 90$^{\circ}$a-a walls in the tetragonal phase region, These stabilized walls resulted from the surface strain had a memory effect in domain formation during the repeated phase transitions and could notr be affected by an external electtric field.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.485-489
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• 2000

A 23.5 kg179, 8 months olds non-spaycd female Rottweiler dog was submitted to the veterinary teaching animal hospitals Chonbuk: national university, for chronic bitten trauma on right foreleg with pain, lameness, and pronation. The patient fought with a neighboring dog about five months ago and had mild anorexia, depression, bolt normal walking at that time. CBC and blood chemical examination were in normal range. Physical examination resulted in the right foreleg with edema and interval rotation of carpal joint. Radiograph of the right carpus showed varus and subluxation. We finally diagnosed the patient as the growth deformity of distal radius and ulna caused by medial premature closure of distal radial physis. Osteotomy was performed fur reforming of the varus of the distal radius and ulna with 6-hole straight plate and six 3.5 mm screws. Panarthrodcsis of carpus was preformed for correcting subluxation using 6-hole T-shaped plate and four 3.5 mm screws with cortical onlay autograft and strengthened by two 3.5 mm screws and tension wire band in lateral aspect of the carpus. Follow-up radiographs after 16 weeds of the surgery showed complete coaptation of osteotomy sire of the radius and uIna. After 6 months of the procedurc, talc plate, screws and the wire were removed except 7-shaped plate and four screws fur arthrodesis. The patient was seen in normal forelimb and could walk and run without lameness after 7 months of the procedure.