• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.329-332
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• 2005

Cross rolling process is one of incremental forming processes to form an axi-symmetric shaped metal component. It can be classified into two types according to the shape of dies, which are a drum type (roll type) and a plate type (straight type). It can also be classified into a wedge type and a ramp type processes according to deformation characteristics of a material. The ramp type die is applied to plate type cross rolling process in cold forming process for forming of teeth of gear or bolt, while the wedge type die is generally utilized to drum type and plate type cross rolling processes in hot forming process. A shape of the ramp type die is usually same as final shape of a product at every section of a progressing direction, while the shape of the wedge type die has different shapes in a progressing direction. In this paper, a rolling of neck part in a ball stud component has been carried out using the plate type cross rolling process with a ramp shaped die. Forming characteristics have been performed using finite element analysis in order to obtain a proper preform for the ramp type plate cross rolling process.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.155-163
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• 2011

The flat type automotive cross members with high strength steel have advantages in light weight and fewer parts compared to the hump type cross members. But the complex part shape of the flat type cross member and the poor formability of high strength steel make it difficult to form the parts without forming defects, such as splits and wrinkles. The purpose of this study is to develop the flat type automotive cross member with high strength steel. For that purpose, drawing processes are evaluated using PAM-$STAMP^{TM}$ and proper draw die and blank designs are proposed. Using the proposed die and blank design, the flat type upper and lower cross member could be formed successfully without forming defects.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.433-437
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• 2005

This paper studied Rotary type ultrasonic motor which has cross type stator. The stator consists of hollowed cross type metal which has four piezoelectric ceramics on the ends of cross bars. When two harmonic voltages which have 90$^{\circ}$ phase difference given to ceramics, the elliptical motion was generated in the inside tips. Inside tips are contact with rotor and these elliptical motions are rotate the rotor The finite element analysis was used to optimize the dimension and displacement of the stator. And the analyzed results were compared with the experimental results of the motor. As results, the speed and the torque of motor was increased by increasing width of the cross bar. And the speed and torque o( motor was not influenced to length of cross bar. The speed and torque was linearly increased by increasing voltage. The maximum torque was generated when the motor fabricated length of cross bar and width of ceramics in the ratio of 1:2.

• Elastomers and Composites
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• v.55 no.1
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• pp.46-50
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• 2020

Material extrusion (ME)-type 3D printing is the most popular among the 3D printing processes. In this study, the cross-section morphologies of ME-type 3D printing manufactured specimens were observed with respect to the thermal properties of the material. The cross-section morphology of a specimen is related to the deposition strength, and the outside profile of the cross-section is related to the surface roughness. The filaments used in this study, with different thermal conductivities, were the acrylonitrile-butadiene-styrene (ABS), the high impact polystyrene (HIPS), the glycol-modified polyethylene terephthalate (PETG), and the polylactic acid (PLA). The cross-sections and the surfaces of the 3D manufactured specimens were examined. In ME-type 3D printing, the filaments are extruded through a nozzle and they form a layer. These layers rapidly solidify and as a result, they become a product. The thermal conductivity of the material influences the cooling and solidification of the layers, and subsequently the cross-section morphology and the surface roughness.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.301-306
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• 2005

The purpose of this study is to make clear the cross-ventilation effect by floor plan type in apartment house during summer. The questionnaire survey was carried out during the 26$^{th}$ of August ${\sim}$ the 4$^{th}$ of September 2004. The respondents were 174 residents living in two subject apartment estates. One subject estate (we call A estate) was consisted apartment houses having cross-ventilation floor plan. The other subject estate (we cail B estate) was constructed apartment houses having ordinary floor plan. The field measurements of indoor thermal elements reflecting natural cooling effect by cross-ventilation were carried out at A house in A estate and at B house in B estate. The measurements in two subject houses were taken on simultaneously the 27$^{th}$ of August. The residents living in A apartment estate planed cross-ventilation type show positive responses on thermal sensation and airflow sensation. The averages indoor temperature and air velocity in the A house were 0.9 $^{\circ}$C lower and 0.29 m/s higher than the B house. Therefore, it was found that indoor thermal environment during summer in the house having cross-ventilation floor plan maintained more comfortable than the house having ordinary floor plan by natural cooling effect of cross-ventilation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.628-631
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• 2001

Current lead is one of the first proposed devices for the application of High Temperature-Superconductor(HTSC). The current lead provides high current for electrical machine using superconductor from room temperature. Its characteristics that is zero resistance and low heat transfer rate under critical temperature lead to research for the replacement of existing current lead with HTSC. In this paper, we investigated the temperature distributions of stacking type and rod type current lead with each cross-section area and length using Nastran program and compared each temperature distribution. It is obtained from this paper that stacking type current lead has flat temperature gradient and than rod type one and more stable operation as current lead is closely related with its cross-section area and length.

• The Journal of the Acoustical Society of Korea
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• v.22 no.3
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• pp.208-216
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• 2003

In one dimensional linear array type piezoelectric ultrasonic transducers widely used for medical diagnosis, the acoustic cross talk caused by the structural acoustic coupling between the adjacent piezoelectric elements reduces significantly their performance. In the study, we have proposed an acoustic wall to reduce the acoustic cross talk by wave propagation through the surface the transducer which can not be prevented by conventional kerf and have analyzed using a finite element method the acoustic cross talk level with respect to the shape, size and materials of the acoustic wall mounted on a convex one dimensional piezoelectric ultrasonic transducer. We expect that the simulated results provide us with a valuable information to make an optimized design of the way type ultrasonic transducer minimizing the acoustic cross talk level.

• International Journal of Costume and Fashion
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• v.16 no.2
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• pp.25-50
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• 2016

The purpose of the study was to identify dimensions of benefit sought where consumer cross-border online shoppers seek and to examine the effects of the dimensions on expectancy, perceived performance, disconformity and satisfaction with cross-border online shopping. A total of 258 data were gathered and analyzed using SPSS 22.0. The results of the study identified that six dimensions of benefit sought of cross-border online shopping, which were economic-efficiency, convenience, uniqueness, scarcity, superiority and conformity seeking. There were significant effects of economic-efficiency, scarcity and uniqueness seeking on the expectancy, perceived performance, and satisfaction. In addition, consumers were segmented as four clusters classified using benefit sought of cross-border online shopping. The four clusters were labeled as "high interest type", "disinterested type", "unique scarcity type", and "price-first unfussy type". The significant differences were found among the clusters in the research constructs of expectancy and disconfirmation theory. The findings of the study suggested practical and managerial implications.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.213-221
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• 2002

This paper presents the experimental result of Reinforced Concrete column-steel beam joint connected by Band Plates(BP). Main parameters in the test are the shape of BP and thickness of plate. Ten interior and exterior RC column-steel beam joint specimens are designed. Cyclic loads are applied to the beam end of eight specimens (four interior specimens and four exterior specimens). To evaluate the cyclic effect, monotonic loads are acted for two specimens. All specimen showed similar failure pattern such as the plate of BP get torn after the large deformation. Even though the specimen with double cross type BP has lower strength than the specimen with single cross type BP, the energy dissipation capacity of the specimen turned out high. Thus, provided the strength of joint with double cross type to be designed to have suitable strength by increasing the thickness of plate, the joint system may show higher seismic capacity.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1179-1186
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• 2006

Cross-linked starch microspheres were prepared using different kinds of cross-linking agents. The influence of several parameters on morphology, size, swelling ratio and drug release rate from these microspheres were evaluated. These parameters included cross-linker type, concentration and the duration of cross-linking reaction. Microspheres cross-linked with glutaraldehyde had smooth surface compared with those prepared with epichlorhydrine or formaldehyde. The particle size increased with increasing the cross-linking time and increasing the drug loading. Swelling ratio of the particles was a function of cross-linker type but not the concentration or time of cross-linking. Drug release from starch microspheres was measured in phosphate buffer and also in phosphate buffer containing a-amylase. Results showed that microspheres cross-linked with epichlorhydrine released all their drug content in the first 30 minutes. However, cross-linking of the starch microspheres with glutaraldehyde or formaldehyde decreased drug release rate. SEM and drug release studies showed that cross-linked starch microspheres were susceptible to the enzymatic degradation under the influence of alpha-amylase. Changing the enzyme concentration from 5000 to 10,000 IU/L, increased drug release rate but higher concentration of enzyme (20,000 IU/L) caused no more acceleration.