• Title/Summary/Keyword: Bulk shape

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Expressive characteristics of genderless style appeared in contemporary women's fashion (현대 여성 컬렉션에 나타난 젠더리스 스타일의 표현특성)

  • Kim, Jihye;Lee, Younhee
    • The Research Journal of the Costume Culture
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    • v.24 no.6
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    • pp.903-919
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    • 2016
  • This study aimed to contribute to the development of various female fashion designs by reviewing the genderless styles in androgynous trends that have loomed large in women's fashion, as well as through analyzing and organizing the changes in women's fashion that were required in a society in which various values coexist. A literature review was conducted to identify the genderless concepts, through which a total of 1,273 materials were selected from 10 brands of the S/S collections, during the period of 2006~2016. The results were as follows: first, without the juxtaposition of incongruous objects or images and a fixed type of color arrangements, the compromise shown in women's fashion were mostly expressed through various tones and diverse colors, and with the mixed use of heterogeneous patterns and materials. Second, the enjoyment of genderless styles was expressed with the unexpectedness that occur through symmetry/asymmetry and harmony/disharmony, as well as through the deviation from conventional notions regarding clothing structures. Third, the exaggeration expressed in women's clothing collections perfectly covered up a woman's body shape with the silhouette of exorbitantly expanded bulk and dimensions. These were done with extended lengths, expanded adornments, and modified clothing design types or structures. Fourth, the sensuality of genderless styles analyzed in women's fashion was expressed with mannish clothing that accentuates the beauty of the female body. Lastly, the historicity shown in genderless styles was expressed through clothing that represented traditional styles of the past, the symbolic meanings expressed in the clothes' colors and patterns, and the methods in which the decorative factors were utilized.

Development of micro check valve with polymer MEMS process for medical cerebrospinal fluid (CSF) shunt system (Polymer MEMS 공정을 이용한 의료용 미세 부품 성형 기술 개발)

  • Chang, J.K.;Park, C.Y.;Chung, S.;Kim, J.K.;Park, H.J.;Na, K.H.;Cho, N.S.;Han, D.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.1051-1054
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    • 2000
  • We developed the micro CSF (celebrospinal fluid) shunt valve with surface and bulk micromachining technology in polymer MEMS. This micro CSF shunt valve was formed with four micro check valves to have a membrane connected to the anchor with the four bridges. The up-down movement of the membrane made the CSF on & off and the valve characteristic such as open pressure was controlled by the thickness and shape of the bridge and the membrane. The membrane, anchor and bridge layer were made of the $O_2$ RIE (reactive ion etching) patterned Parylene thin film to be about 5~10 microns in thickness on the silicon wafer. The dimension of the rectangular nozzle is 0.2*0.2 $\textrm{mm}^2$ and the membrane 0.45 mm in diameter. The bridge width is designed variously from 0.04 mm to 0.12 mm to control the valve characteristics. To protect the membrane and bridge in the CSF flow, we developed the packaging system for the CSF micro shunt valve with the deep RIE of the silicon wafer. Using this package, we can control the gap size between the membrane and the nozzle, and protect the bridge not to be broken in the flow. The total dimension of the assembled system is 2.5*2.5 $\textrm{mm}^2$ in square, 0.8 mm in height. We could precisely control the burst pressure and low rate of the valve varing the design parameters, and develop the whole CSF shunt system using this polymer MEMS fabricated CSF shunt valve.

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Computer-simulation with Different Types of Bandgap Profiling for Amorphous Silicon Germanium Thin Films Solar Cells

  • Jo, Jae-Hyeon;Lee, Jun-Sin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.320-320
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    • 2014
  • Amorphous silicon alloy (a-Si) solar cells and modules have been receiving a great deal of attention as a low-cost alternate energy source for large-scale terrestrial applications. Key to the achievement of high-efficiency solar cells using the multi-junction approach is the development of high quality, low band-gap materials which can capture the low-energy photons of the solar spectrum. Several cell designs have been reported in the past where grading or buffer layers have been incorporated at the junction interface to reduce carrier recombination near the junction. We have investigated profiling the composition of the a-SiGe alloy throughout the bulk of the intrinsic material so as to have a built-in electrical field in a substantial portion of the intrinsic material. As a result, the band gap mismatch between a-Si:H and $a-Si_{1-x}Ge_x:H$ creates a barrier for carrier transport. Previous reports have proposed a graded band gap structure in the absorber layer not only effectively increases the short wavelength absorption near the p/i interface, but also enhances the hole transport near the i-n interface. Here, we modulated the GeH4 flow rate to control the band gap to be graded from 1.75 eV (a-Si:H) to 1.55 eV ($a-Si_{1-x}Ge_x:H$). The band structure in the absorber layer thus became like a U-shape in which the lowest band gap was located in the middle of the i-layer. Incorporation of this structure in the middle and top cell of the triple-cell configuration is expected to increase the conversion efficiency further.

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Manufacture of $BaTiO_3$ Powders by Gel-hydrothermal Method (겔의 수열합성법에 의한 다공성 구형 $BaTiO_3$ 미분체의 제조)

  • Kim, Yong-Ryul
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.306-314
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    • 2005
  • In this study, spherical $pre-BaTiO_3$ particles are prepared by gelation and aging process in autoclave without catalysts. The (Ba-Ti) gel used as a starting material was prepared by aging mixtures of titanyl acylate with barium acetate aqueous solution([glacial acetic acid (AcOH)]/[titanium isopropoxide (TIP)] 4, [barium acetate]/[TIP] 1) at $45^{\circ}C$ for 48hrs. XRD and SEM results for the (Ba-Ti) gel sample at aging process showed that the gel was formed via aggregation of the fine particles. It seems to be the primary particles of bulk (Ba-Ti) gel amorphous, but the spatial arrangement of barium and titanium in the (Ba-Ti) gel is similar to that in crystalline $BaTiO_3$ particles. From XRD and FT-IR. spectroscopy analysis it was found that the crystal structure of the prepared particles continuously transformed from amorphous to tetragonal as the calcination temperature increased, and crystallized spherical cubic and tetragonal $BaTiO_3$ powder obtained at the very low calcination temperature between $500^{\circ}C$ and $900^{\circ}C$ after 1hrs of heat treatment respectively. According to BET analysis result, final particle have pore structure of ink bottle shape which is produced by aggregation of fine spherical particles with surface area of $280m^2/g$ and average pore size of 130nm.

Numerical Analysis of the Initiation and Development of Corrugation on a Gravel Road (수치해석적 기법을 활용한 골재 도로의 콜루게이션 발생 및 진전 분석)

  • Yun, Taeyoung;Chung, Taeil;Shin, Hyu-Soung
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.9-18
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    • 2018
  • PURPOSES : In this research, the initiation and development of corrugation on a gravel road with certain wheel and boundary conditions were evaluated using a coupled discrete-element method (DEM) with multibody dynamics (MBD). METHODS : In this study, 665,534 particles with a 4-mm diameter were generated and compacted to build a circular roadbed track, with a depth and width of 42 mm and 50 mm, respectively. A single wheel with a 100-mm diameter, 40-mm width, and 0.157-kg mass was considered for the track. The single wheel was set to run slowly on the track with a speed of 2.5 rad/s so that the corrugation was gradually initiated and developed without losing contact between the wheel and the roadbed. Then, the shape of the track surface was monitored, and the movement of the particles in the roadbed was tracked at certain wheel-pass numbers to evaluate the overall corrugation initiation and development mechanism. RESULTS : Two types of corrugation, long wave-length and short wave-length, were observed in the circular track. It seems that the long wave-length corrugation was developed by the longitudinal movement of surface particles in the entire track, while the short wave-length corrugation was developed by shear deformation in a local section. Properties such as particle coefficients, track bulk density, and wheel mass, have significant effects on the initiation and development of long-wave corrugation. CONCLUSIONS : It was concluded that the coupled numerical method applied in this research could be effectively used to simulate the corrugation of a gravel road and to understand the mechanism that initiates and develops corrugation. To derive a comprehensive conclusion for the corrugation development under various conditions, the driver's acceleration and deceleration with various particle gradations and wheel-configuration models should be considered in the simulation.

Relative Timing of Shear Zone Formation and Granite Emplacement in the Yechon Shear Zone, Korea (예천(醴泉) 전단대(剪斷帶)의 생성(生成)과 화강암(花崗岩) 관입(貫入)의 상대적(相對的)인 시기(時期))

  • Chang, Tae Woo
    • Economic and Environmental Geology
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    • v.23 no.4
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    • pp.453-463
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    • 1990
  • The Yechon shear zone developed by strike-slip movement was formed in a relatively high temperature condition just after the Jurassic syntectonic granites had been emplaced during Daebo Orogeny. Post-emplacement formation of the shear zone is favored by continuity of foliations and lineations within and without the granites, development of mylonitic structures in the wallrocks, deformation of pegmatite and felsite dikes, and pretectonic growth of porphyroblasts in the wallrocks. A variety of shear sense indicators in the shear zone are predominantly observed in the intensely to extremely deformed rocks. They show that bulk non-coaxial detormation has occurred, and that the sense of shear is consistently dextral with S-C fabrics, grain shape fabrics, asymmetric porphyroclast systems, mica fish, asymmetric extension structures and quartz C-axis fabrics.

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Effect of addition of dispersant on the physical properties of recycled zirconia (분산제의 첨가가 재활용 지르코니아의 물성에 미치는 영향)

  • Seo, Jeong-Il;Park, Won-Uk;Kim, Hae-Gyu
    • Journal of Technologic Dentistry
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    • v.40 no.1
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    • pp.17-25
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    • 2018
  • Purpose: When casting of ceramics, proper amount of deflocculant was added for disperse the particles in slip. In this study, examined the optimum amount of APMA(ammonium polymethaacrylate) water as deflocculant for casting the zirconia. Methods: The 100 g of zirconia powder were ball milled with 300 g zirconia ball, 90 g of distilled water, and APMA water in polyethylene pot for 24 hours. The amount of APMA water were added as deflocculant from 0.5 to 0.9 g at an intervals of 0.1 g. The viscosity of slip with no deflocculant showed 1362c.p. and the minimum viscosity with 580c.p. obtained when the slip contained 0.7% of deflocculant. Bar type specimens were casted with plaster mold and biscuit fired at $1100^{\circ}C$ for 1 hours. Biscuit fired specimens were finished with $60mm(L){\times}14mm(W){\times}10mm(H) bar$. Finished specimens were 2nd fired at $1500^{\circ}C$ for 1 hour. Results: Regardless the addition of deflocculant, all 2nd fired specimens showed 0% of apparent porosity and water absorption. The specimens with no deflocculant showed 24% of drying shrinkage and 27.4% firing shrinkage. On the other hand, The specimens with deflocculant showed 17.4% of drying shrinkage and 17.6% firing shrinkage regardless the amount of deflocculant. The maximum bulk density with $6.09g/cm^3$ obtained when the specimens casted with 0.7~0.9% of deflocculant contained slips. Bend strength of specimen with no deflocculant showed 680 MPa and the maximum bend strength with 814 MPa obtained when the specimen casted with 0.7% of diflocculant contained slip. Conclusion : It was found that the particle shape of the powder according to the dispersing agent is added, the particle size, sintering temperature and affect the particle size distribution, sintering time, sintering atmosphere, such a great influence on the sintering.

Colloidal synthesis of IR-Iuminescent HgTe quantum dots (콜로이드 합성법에 의한 HgTe 양자점의 제조와 특성 분석)

  • Song, Hyun-Woo;Cho, Kyoung-Ah;Kim, Hyun-Suk;Kim, Sang-Sig
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.31-34
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    • 2002
  • HgTe quantum dots were synthesized in aqueous solution at room temperature by colloidal method. The synthesized materials were identified to be zincblende cubic structured HgTe quantum dots by X-ray diffraction and transmission electron microscopy image revealed that these quantum dots are agglomerate of a individual particle. The colloidally prepared HgTe quantum dots have the sphere-like shape with a diameter of approximately 4 nm. The optical properties of the HgTe quantum dots were investigated with photoluminescence(PL). The PL appears in the near-infrared region, which represent a dramatic shift from bulk HgTe behavior. The analytic results revealed that HgTe quantum dots have the broad size distribution, as PL emission spectrum covers the spectral region from 900 to 1400 nm. In this study, the factors affecting PL of HgTe quantum dots and particle size distributiont are described.會Ā᐀䁇?⨀젲岒Ā㰀會Ā㰀顇?⨀끩Ā㈀會Ā㈀?⨀䡪ఀĀ᐀會Ā᐀䡈?⨀Ā᐀會Ā᐀ꁈ?⨀硫ᜀĀ저會Ā저?⨀샟ගऀĀ저會Ā저偉?⨀栰岒ఀĀ저會Ā저ꡉ?⨀1岒Ā저會Ā저J?⨀惝ග؀Ā؀會Ā؀塊?⨀ග嘀Ā切會Ā切끊?⨀⣟ගĀ搀會Ā搀ࡋ?⨀큭킢Ā저會Ā저恋?⨀桮킢Ā저會Ā저롋?⨀⣅沥ࠀĀࠀ會Āࠀ၌?⨀샅沥Ā저會Ā저桌?⨀壆沥ሀĀ저會Ā저쁌?⨀o킢瀀ꀏ會Āᡍ?⨀棤좗ĀĀĀ會ĀĀ灍?⨀å좗ĀĀĀ會ĀĀ졍?⨀飥좗ĀĀĀ會ĀĀ⁎?⨀?ꆟᤀ

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Influence of Li2O Addition on Physical Properties of Glass-Ceramics Fabricated Using a Coal Bottom Ash (석탄바닥재로 제조된 결정화 유리의 물리적 특성에 미치는 Li2O 첨가 영향)

  • Um, Noo-Li;Kang, Seung-Gu
    • Korean Journal of Materials Research
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    • v.20 no.2
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    • pp.72-77
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    • 2010
  • Glass-ceramics were fabricated by heat-treatment of glass obtained by melting a coal bottom ash with $Li_2O$ addition. The main crystal grown in the glass-ceramics, containing 10 wt% $Li_2O$, was $\beta$-spodumene solid solution, while in $Li_2O$ 20 wt% specimen was mullite, identified using XRD. The activation energy and Avrami constant for crystallization were calculated and showed that bulk crystallization behavior will be predominant, and this expectation agreed with the microstructural observations. The crystal phase grown in $Li_2O$ 10 wt% glass-ceramics had a dendrite-like shaped whereas the shape was flake-like in the 20 wt% case. The thermal expansion coefficient of the $Li_2O$ 10 wt% glass-ceramics was lower than that of the glass having the same composition, owing to the formation of a $\beta$-spodumene phase. For example, the thermal expansion coefficient of $Li_2O$ 10 wt% glass-ceramics was $20\times10^{-7}$, which is enough for application in various heat-resistance fields. But above 20 wt% $Li_2O$, the thermal coefficient expansion of glass-ceramics, on the contrary, was higher than that of the same composition glass, due to formation of mullite.

Characteristics Analysis of a Pseudoelastic SMA Mesh Washer Gear for Jitter Attenuation of Stepper-actuated Gimbal-type Antennas (스텝모터 구동형 짐벌 안테나의 미소진동저감을 위한 초탄성 형상기억합금 메쉬 와셔 기어의 기본특성 분석)

  • Park, Yeon-Hyeok;You, Chang-Mok;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.12 no.2
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    • pp.46-58
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    • 2018
  • A two-axis gimbal-type X-band antenna is widely used to transmit bulk image data from high-resolution observation satellites. However, undesirable microvibrations induced by driving the antenna should be attenuated, because they are a main cause of image-quality degradation of the observation satellite. In this study, a pseudoelastic memory alloy (SMA) gear was proposed to attenuate the microvibrations by driving the antenna in an azimuth angle. In addition, the proposed gear can overcome the limitations of the conventional titanium blade gear, which is not still enough and is vulnerable to plastic deformations under excessive torque. To investigate the basic characteristics of the proposed SMA mesh washer gear, a static load test was performed on the thickness of the SMA mesh washer and the rotation of the gear. Moreover, The microvibration measurement test demonstrated that the SMA mesh washer gear proposed in this study is effective for microvibration attenuation.