• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.349-352
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• 2008

In this study, a design method of developed shape for double-curved pressure vessel segment heads was proposed in consideration of in-plane strain induced by forming works. In order to obtain the developed shape of double-curved plate, at first, the segments are subdivided into elements and then they are stacked into a series of strips producing the outline of the approximately developed shape. The developed shape was determined by imposing the in-plane displacement obtained from forming analysis and regression analysis on the outline of the approximately developed shape. The validation of the proposed design method was verified by applying it to the actual products.

• Advances in concrete construction
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• v.10 no.1
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• pp.61-69
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• 2020

This paper looks into how the shape of headed bars may influence the durability of reinforced concrete structures. Nowadays the only heads used in site works are cylindrical in shape. An alternative shape of head is studied in this piece of work. The new head reduces the concentration of stresses and so the appearance of cracks. In this work durability is studied based on both, first cracking and failure mode. An experimental campaign of 12 specimens and finite element modelling are described. The specimens were subjected to an accelerated corrosion process using an electrical current supply. Direct current was impressed on the specimens until breaking. Test results and the results obtained from numerical models are presented. Results are presented in term of comparison between the two shapes of heads studied. It was shown that the shape of the head has a significant influence on durability of reinforced concrete structures with headed reinforcing bars.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.894-904
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• 2005

The flow structure inside the intake head greatly affects the working efficiency of a vacuum cleaner such as suction power and aero-acoustic noise. In this study, the flow inside intake heads of a vacuum cleaner was investigated using qualitative flow visualization and quantitative PIV (Particle Image Velocimetry) techniques. The aerodynamic power, suction efficiency and noise level of the intake heads were also measured. In order to improve the performance of the vacuum cleaner, inner structure of the flow paths of the intake head, such as trench height and shape of connection chamber were modified. The flow structures of modified intake heads were compared with that of the original intake head. The aero-acoustic noise caused by flow separation was reduced and the suction efficiency was also changed due to flow path modification of intake head. In this paper, the variations of flow fields for different intake heads are presented and discussed together with results of aerodynamic power, suction efficiency and noise level.

• Fire Science and Engineering
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• v.18 no.4
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• pp.35-41
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• 2004

The water spray characteristics of the sprinkler heads is a very important factor affecting the fire suppression performance, and it is largely dependent on the shape of the head nozzle. This study investigated shape factors and spray distribution performances for the sprinkler heads of four domestic companies with big market shares. The experimental results revealed that all flow constants exceeded the required regulation limits, however showed big differences between head types although they have the same design limit. They were however relatively consistent regardless of the pressure increases. The spray distribution of some head samples showed severe directional eccentricity, which suggests more study for the improvement.

• Journal of Fashion Business
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• v.15 no.6
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• pp.23-39
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• 2011

Scythian Earrings in the Black Sea region had completely degenerated, stifled by motifs and shapes of Greek origin, retaining its representational realism and its full emotional vitality. The purpose of this study is to review and research the symbolic meaning and classifying the types of the Scythian Earrings style through the tombs bequests. The Scythian Earrings were divided into the styles according to the shape, Earring with Ends Shaped like animal's Heads, Boat-Shaped Earrings, Bird-Shaped Pendants earrings, Earrings with a Disc and a Pendant, Earrings Shaped like the Figures, Earring with the drop Pendant, Spiral Earrings. Earrings based on the boat shape enjoyed a long popularity among the Scythians. As that form became elaborated and combined with the disk-pendent, it reflected native rather than Asian or Hellenic tastes. Although Scythian earrings were produced based on the shapes of Greece earrings, they recreated these as Scythian unique style. In particular, the animal motive and the decoration have various changes. The exquisite earrings attest to the elegant taste and splendid wealth of the upper classes.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.367-378
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• 2005

The purpose of this study was to analyse craniofacial shape by 3D scanner for female adults with age groups. In this study, heads of 452 female adults were measured by 3D scanner. The obtained 25 measurements were analyzed by statistical methods. The results can be summarized as follows; 1. From the basic statistical data analysis, vertex-tragion and the length between the pupils were the longest in their twenties, and grew shorter in elderly groups. The length of nasion-subnasale and the width of mouth increased with an increased in age. 2. According to the analysis of the craniofacial proportions, the head type of female aduls was short-headed. The size of lower face increased with an increase in age. 3. The statistically noticeable differences were found in the measurement of the left and the right sides of face in the age groups of 20, 30, and 40. 4. High correlations were found in two perpendicular lengths, two horizontal lengths and two widths. 5. The order of factor analysis was as follows; the horizontal length, the perpendicular length and the width from highest.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1414-1417
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• 2004

A thick-layered RP process, transfer-type variable lamination manufacturing using expandable polystyrene foam (VLMST) has been developed to have the advantageous characteristics such as high building speed, low cost for introduction and maintenance of VLM-ST apparatus, and little staircase surface irregularities of parts. However, VLM-ST has difficulty fabricating an axisymmetric shape and a large-sized freeform shape because of the limited sloping angles and small build size. The objective of this paper is to develop a multi-functional hotwire cutting system using EPS-foam (MHC). MHC employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turntable. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated on the apparatus.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.11
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• pp.32-41
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• 2000

A new anatomical head model was implemented based on the MR and CT images of the head of a volunteer whose head shape is close to the domestic standard. In order to compare SARs (specific absorption rates) of heads with different shapes, we calculated SARs in the two anatomical head models. The one is the new model and the other is that of the black race and was made at National Library Medicine in USA. The head model and a phone model were arranged in the computational space to be the touch or cheek position of CENELEC (European Committee for Electrotechnical Standardisation) and FCC guidelines. From the obtained results, we can see that the smaller head produces the higher whole head-averaged SAR. However, it seems that the localized SAR averaged over 1 g or 10 g is more dependent on the shape of the auricle rather than that of the head size.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.194-202
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• 2005

The objective of this paper is to develop a multi-functional hotwire cutting system (MHC) using EPS-foam block or plate as the working material. Because the MHC apparatus employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turntable, it allows the easy fabrication of various 3D shapes, such as (1) an axisymmetric shape or a sweeping cross-sectioned pillar shape using the hot-strip in the form of sweeping surface and EPS foam block on the turntable, (2) a polyhedral complex shape using the hotwire and EPS foam block on the turntable, and (3) a ruled surface approximated freeform shape using the hotwire and EPS foam plate. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated on the apparatus.

• Journal of the Korean Home Economics Association
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• v.43 no.6 s.208
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• pp.13-25
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• 2005

The purpose of this study was to analyse craniofacial shape by 3D scanner for Korean adult head shape by age group. The heads of 836 adults were measured by 3D scanner, and the 25 obtained measurements were analyzed by statifical methods. The results can be summarized as follows. 1. From the basic statistical data analysis, the vertex-tagion and the length between the pupils were the longest in the subjects in their twenties, and decreased in elderly groups. 2. According to the analysis of the craniofacial proportion, the typical adult Korea head type was short-headed. 3. Statistically noticeable differences were found in the ectocanthion- opistcranion by the measurement of the left and the right sides of face in the age groups of the 20s, 30s, 40s, and 50s. 4. The order of factor analysis was as follows: the horizontal length, the perpendicular length and the width from the highest in the age group of the 20s, 30s, 40s, and 50s.