• 제목/요약/키워드: Constant Comparison Method

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Design Characteristics of Augmented Reality Digital Fashion (증강 현실 디지털 패션의 디자인 특성)

  • Eunjeong Kim;Seunghee Suh
    • Journal of Fashion Business
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    • v.28 no.4
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    • pp.1-20
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    • 2024
  • The aim of this study was to analyze contemporary sociocultural phenomena and values through characteristics of augmented reality (AR) digital fashion design. The research method included a literature review on the metaverse and augmented reality, combined with a case study using both quantitative analysis through big data text mining and qualitative analysis through constant comparison. Data analysis was conducted using Python-based open-source tools: First, 6,725 data entries were collected from AR digital fashion platforms and brands identified in articles from Vogue and Vogue Business containing keywords of 'augmented reality' and 'digital fashion. Second, text preprocessing involved stop word removal, tokenization, and POS-tagging of nouns and adjectives using the NLTK library. Third, top 50 keywords were extracted through term frequency (TF) and TF-IDF analysis, with results visualized using a word cloud. Fourth, characteristics of products' external design and internal concepts that contained top keywords were classified, with their value examined through repeated comparison. Results indicate that AR digital fashion design has the following characteristics. First, it embodies surreal fantasy through designs that mimic natural biological patterns using 3D scanning and modeling technology. Second, it presents a trans-boundary aspect by utilizing the fluidity of body and space to challenge vertical and discriminatory social structures. Third, it imagines a new future transcending traditional sociocultural concepts by expanding perceptions of space and time based on advanced technological aesthetics. Fourth, it contributes to sustainability by exploring alternatives for the fashion industry in response to climate change and ecological concerns.

The Machining Technique of Connecting Rod through Constant Control of Cutting Speed Method in Ball End Mill Machining (볼엔드밀 가공에서 절삭속도 일정제어기법에 의한 커넥팅로드 가공기술)

  • Kang, Myung-Chang;Jung, Young-Ho;Kim, Jeong-Suk;Moon, Sung-Jun;Kim, Kyung-Kyoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1053-1059
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    • 2002
  • The purpose of this study is to suggest how the machining technique of constant control of cutting speed can improve precision machining and tool life in high speed machining using a ball end mill. Cutting speed is changed in machining fee form surfaces such as connecting rod die. So, we don't have supreme surface form and tool life on machining. To solve this problem we should settle on optimal cutting speeds in free form surface machining. And, to improve precision machining, We must execute high speed machining methods to output optimum NC data using developed constant control of cutting speed program after modeling by CAD/CAM. In this paper, a comparison was made of the cutting precision and tool life in conventional cutting and those in connecting rod machining applying the program developed.

A Study on Soot Formation of Turbulent Premixed Propane Flames in n Constant-Volume Combustor at High Temperatures and High Pressures (고온ㆍ고압 정적 연소기내 난류 프로판 예혼합 화염의 매연생성에 관한 연구)

  • 배명환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.1-9
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    • 2001
  • The soot yield has been studied by a premixed propane-oxygen-inert gas combustion in a specially designed disk-type constant-volume combustion chamber to investigate the effects of pressure, temperature and turbulence on soot formation. Premixtures are simultaneously ignited by eight spark plugs located on the circumference of chamber at 45 degree intervals in order to observe the soot formation under high pressures. The eight flames converged compress the end gases to a high pressure. The laser schlieren and direct flame photographs for observation field with 10 mm in diameter are taken to examine into the behaviors of flame front and gas flow in laminar and turbulent combustion. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in situ laser extinction technique and simultaneously the corresponding burnt gas temperature by the two-color pyrometry method. The pressure and temperature during soot formation are changed by varying the initial charge pressure and the volume fraction of inert gas compositions, respectively. It is found that the soot yield increases with dropping temperature and rising pressure at constant equivalence ratio, and that the soot yield of turbulent combustion decreases in comparison with that of laminar combustion because the burnt gas temperature increases with the drop of heat loss.

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A Study on the Performance Comparison Method of MTI Signal Processors Against Ground Clutter (지상클러터에 대한 MTI 신호처리기의 성능 비교 방법에 관한 연구)

  • 구연건;김두근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.10 no.2
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    • pp.82-87
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    • 1985
  • The performance comparison method against ground clutter, when the trasnfer function of MTI filter or integrator is given, is considered for the MTI signal processors using a constant PRF. The MTI signal processors are modelled as the transversal filters, and the ground clutter power density spectrum as Gaussian type and the performance of the MTI signal processors are compared by calculating the MTI improvent factors. The MTI imrpovement factors versus normalized spectral width is depicted as examples for the MTI filters, the integrator using Hanning weighting function and the cascading of the two.

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Pyroelectric Peyformance Evaluation of Pure PZT and Alternately Deposited PZT/PT Thin Films (PZT 순수박막과 PZT/PT 교차박막의 적외선 감지 특성 비교)

  • Ko, Jong-Soo;Kwak, Byung-Man
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1001-1007
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    • 2002
  • To improve the performance of the PZT thin flms, each PZT and PT layer was alternately deposited on a Pt/Ti/Si$_3$N$_4$/SiO$_2$/Si substrate by a modified sol-gel solid precursor technique. For comparison, PZT thin films were also prepared with an identical method under the same conditions. XRD measurement revealed that the diffraction pattern of the multilayer film was due to the superimposition of the PZT and PT patterns. At 1㎑, a dielectric constant of 389 and 558, a dielectric loss of 1.2% and 1.1% were obtained for the PZT/PT and PZT thin films, respectively. If we consider the PT dielectric constant to be 260, it is clear that the dielectric constant of alternately deposited PZT/PT thin films was well adjusted. The PZT/PT thin film showed a low dielectric constant and a similar dielectric loss compared with those of the PZT film. The figures of merit on detectivity for the PZT/PT and PZT thin films were 20.3$\times$10$\^$-6/㎩$\^$-$\sfrac{1}{2}$/, and 18.7$\times$10$\^$-6/㎩$\^$-$\sfrac{1}{2}$/, and the figures of merit on voltage response were 0.038㎡/C and 0.028 ㎡/C, respectively. The high figures of merit for the PZT/PT film were ascribed to its relatively low dielectric constant when compared to the PZT thin films.

A Study on the Rapid Bulk Combustion of Premixture Using the Radical Seeding

  • Lee, Myung-Jun;Kim, Jong-Youl;Park, Jong-Sang;Yeom, Jeong-Kuk;Chung, Sung-Sik
    • Journal of Mechanical Science and Technology
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    • v.18 no.9
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    • pp.1623-1629
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    • 2004
  • The objective of this study is the rapid bulk combustion of mixture in a constant volume chamber with a tiny sub-chamber. Some narrow passage holes were arranged to induce simultaneous multi-point ignition in the main chamber by jet of burned and unburned gases including radicals from the sub-chamber, and the equivalence ratios of pre-mixture in the main chamber and the sub-chamber were the same. The principal factors of the Radical Induced Auto-Ignition (RIAI) method are the diameter of the passage holes and the volume of sub-chamber. The relationship between the sub-chamber and diameter of passage hole was represented by the ratios of sub-chamber volume to passage hole volume. The ratios are non-dimensional coefficients for sub-chamber characteristics. As a result, the RIAI method reduced the combustion period, which expanded the lean limit in comparison with SI method.

EXAMINATION OF SPATIAL INTEGRATION METHOD FOR EXTRACTING THE RCS OF A CALIBRATION TARGET FROM SAR IMAGES

  • Na, Jae-Ho;Oh, Yi-Sok
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.254-257
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    • 2007
  • This paper presents an examination of the spatial integration method for extracting the RCS of a trihedral corner reflector from SAR images for SAR external calibration. An exact external radiometric calibration technique is required for extracting an exact calibration constant. Therefore, we examine the accuracy of the spatial integration method, which is commonly used for the SAR external radiometric calibration. At first, an SAR image for a trihedral corner reflector is simulated with a high-resolution SAR impulse response with a known theoretical RCS of the reflector, and a background clutter image for the high resolution SAR system is also generated. Then, a SAR image in a high resolution is generated for a trihedral comer reflector located on a background clutter by superposition of the two SAR images. The radar cross section of a trihedral corner reflector in the SAR image is retrieved by integrating the radar signals of the pixels adjacent to the reflector for various size of the integration area. By comparison of the measured RCS by the integration method and the theoretical RCS of the reflector, the effect of the size of the integration area on the extraction of the calibration constant is examined.

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A Comparison of High Frequency Properties of LTCC Substrate Systems (LTCC 기판 시스템의 고주파 특성 비교)

  • 이영신;김경철;박성대;박종철
    • Journal of the Microelectronics and Packaging Society
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    • v.9 no.3
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    • pp.7-12
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    • 2002
  • In the measurement of the RF properties, the LTCC substrate must be considered as a system including various conductor patterning processes. In this paper, the LTCC substrate system is compared with a conventional PCB(Printed Circuit Board) substrate such as FR-4, Duroid and Teflon, etc. The microstrip resonator method is employed for the measurement of the RF properties in the range of DC to 20 GHz. Experimental results show that the ring resonator method is suitable for system loss measurement, and the series gap resonator method for dielectric constant measurement. The process of conductor patterning and its effect on the system loss were also studied.

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A Comparison of Efficiency of Decolorizing Rhodamine B using Lab-Scale Photocatalytic Reactors : Slurry Reactor, IWCR and PFBR

  • Na, Young-Soo;Lee, Tae-Kyung;Lee, Song-Woo;Lee, Chang-Han;Kim, Do-Han;Park, Young-Seek;Song, Seung-Koo
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_4
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    • pp.157-164
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    • 2001
  • The performance of fluidized-bed reactor with Photomedia, immobilized TiO$_2$ onto the porous ceramic ball using a sol-gel method has been studied in this work. A simple model substrate, dilute Rhodamine B (RhB), was decolorized at room temperature. For the purpose of comparison, the slurry reactor and the Inner Wall Coated Reactor (IWCR) were used. The aim of this work was to develop the photocatalytic fluidized bed reactor (PFBR) through contrasting the photodegradability of various reactors such as the TiO$_2$slurry reactor, the inner-wall coated reactor (IWCR). In this study, the RhB was decolorized in three types of reactor. Even though the reaction rate constant of PFBR was lower than that of slurry reactor, PFBR had the advantages of preventing the wash-out of photocatalyst, so it can be operated continuously.

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A Comparison of Soil Hydraulic Conductivities Determined by Three Different Methods in a Sandy Loam Soil (토양(土壤)의 포화투수계수(飽和透水係数) 측정법(測定法) 비교(比較) 연구(硏究))

  • Park, Moo-Eon;Yoo, Sun-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.16 no.1
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    • pp.14-19
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    • 1983
  • Comparison and evaluation of various wellknown methods to determine the saturated hydraulic conductivity of soil were attempted in order to choose a convenient and reliable method applicable, at least, to Bonryang sandy loam (coarse loamy over sandy, mixed, mesic family of Typic Udifluvents). Three experimental methods, inversed auger hole, infiltrometer, and core sample method, were used for this purpose. The results were summarized as follows: 1. The inversed auger hole method was highly correlated with the infiltrometer method while the core sample method was poorly correlated with other two methods. 2. The inversed auger hole method was proved to be convenient and reliable method to measure the hydraulic conductivity of upland coarse textured soils in situ. 3. The hydraulic conductivity determined by the infiltrometer method converged to a constant value after 80 to 100 minutes from starting of measurement. 4. The conductivity determined by the inversed auger hole method approached to a constant value at 5 or 6th run of measurement. 5. The hydraulic conductivity determined by the core sample method was greatly under estimated in comparison with the values obtained by other two methods.

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