• Title/Summary/Keyword: Minimal surface

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Reattachment of amputated auricle using postauricular subcutaneous pocket (귓바퀴 뒤 포켓을 이용한 절단된 외이의 재접합)

  • Jang, Ju Yun;Kang, Dong Hee;Lee, Chi Ho;Oh, Sang Ah
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.660-662
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    • 2009
  • Purpose: There are several modalities to reattach the amputated auricle. Microvascular replantation can achieve the best outcome, but technically difficult. Conventional composite graft is technically easy, but uniformly unsuccessful. Our successful experience of reattachment using postauricular subcutaneous pocket is presented. Methods: The amputated tissue was placed in its anatomical position with buried sutures. The amputated part is dermabraded to remove the epidermis and outer layer of dermis(Fig. 1, Center, left). Postauricular skin flap was then raised and the reattached dermabraded ear was buried beneath the flap(Fig. 1, Center, right). Two weeks after the original surgery, the buried ear was removed from its pocket (Fig. 1, Below, left). Results: The ear was reepithelialized spontaneously in 7 days. At 3 months, the reattached ear has satisfactory appearance without contour deformity(Fig. 1, Below, right). Conclusion: This technique provides increase in contact surface between the amputated segment and the surrounding tissues which supply blood, serum, oxygen and nutrients, maximizing the probability of "take". Minimally injured dermis can be healed from spontaneous reepithelialization and provides minimal contour deformity. We have used this non-microsurgical technique with very satisfying outcome.

Sensitivity analysis of effective imperviousness estimation for small urban watersheds (도시 소유역 유효불투수율의 민감도 분석)

  • Kim, Dae Geun;Ko, Young Chan
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.181-187
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    • 2009
  • In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

Effects of Stiffeners on Vibro-acoustic Response of Rectangular Flat Plate (보강재가 평판 진동 및 음향 특성에 미치는 영향)

  • Park, Jeong-Won;Kim, Dong-Kyu;Koo, Man-Hoi;Park, Jun-Hong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.7
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    • pp.622-628
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    • 2011
  • The purpose of this study was to analyze the vibro-acoustic characteristics of a stiffened rectangular plate at high frequencies. The stiffeners attached along the plate surface were assumed to have rotational and translational stiffness and inertia. The harmonic response of the stiffened plate were predicted and compared using the Rayleigh-Ritz method with two different trial functions - polynomial and beam functions. The variation of the spatially averaged mean square velocity and the modal characteristics with the number of stiffeners were obtained. The use of the beam function ensured fast convergence which was essential for analyzing the high frequency vibration responses. Using the calculated modal characteristics and the Rayleigh-integral, the radiated sound power was predicted, and the effects of stiffeners were investigated. The proposed model can be applied to study optimal layout of stiffeners for minimal noise generation of the stiffened structures.

Ultra- and Nano-Filtration Process Optimization of Isoflavones and Oligosaccharides from Sunmul

  • Kim, Woo-Jung;Kim, Hak-Hyun;Yoo, Sang-Ho
    • Food Science and Biotechnology
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    • v.14 no.3
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    • pp.380-386
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    • 2005
  • Optimal conditions of ultrafiltration (UF) and nanofiltration (NF) were investigated for separation and concentration of isoflavones and oligosaccharides from Sunmul. Levels of COD, BOD, and suspended solids (SS) in UF and NF permeates were also determined to evaluate effectiveness of these processes for reducing water pollution. Optimal UF operation conditions to achieve minimal fouling and maximal flux were $33-34^{\circ}C$ operating temperature and 2.3-2.4 bar trans-membrane pressure. Recovery yields of isoflavones and oligosaccharides in UF retentate were 11.49-28.16% and 12.77-27.57%, respectively. Increase in volumetric concentration factor (VCF) resulted in more functional compounds of isoflavones and oligosaccharides passing through UF membrane. Total isoflavone and oligosaccharide yields decreased by 3% as VCF increased from 6.0 to 8.0 and from 8.0 to 10.0, while decreased significantly by 10% as VCF decreased from 4.0 to 6.0. Optimal NF operating conditions were 192-195 psig operating pressure at $30-33^{\circ}C$. Total yields of isoflavones and oligosaccharides significantly decreased at VCF 8.0, whereas did not decrease up to VCF 6.0 during NF operation. Therefore, VCF 6.0 was recommended for economical process. COD and BOD decreased by more than 98% after NF process, and SS were not detected after UF process. These results indicated sequential filtration process was useful for separation of isoflavones and oligosaccharides from Sunmul and for reducing water contaminants.

Efficient Designs to Develop a Design Space in Quality by Design (설계기반 품질고도화에서 디자인 스페이스 구축을 위한 효율적인 실험계획)

  • Chung, Jong Hee;Kim, Jinyoung;Lim, Yong B.
    • Journal of Korean Society for Quality Management
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    • v.47 no.3
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    • pp.523-535
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    • 2019
  • Purpose: We research on the efficient response surface methodology(RSM) design to develop a design space in Quality by Design(QbD). We propose practical designs for the successful construction of the design space in QbD by allowing different number of replicates at the box points, star points, and the center point in the rotatable central composite design(CCD). Methods: The fraction of design space(FDS) plot is used to compare designs efficiency. The FDS plot shows the fraction of the design space over which the relative standard error of predicted mean response lies below a given value. We search for practical designs whose minimal half-width of the tolerance interval per a standard deviation is less than 4.5 at 0.8 fraction of the design space. Results: The practical designs for the number of factors between two and five are listed. One of the designs in the list could be chosen depending on the experimental budget restriction. Conclusion: The designs with box points replications are more efficient than those with the star points replication. The sequential method to establish a design space is illustrated with the simulated data based on the two examples in RSM.

An IE-FFT Algorithm to Analyze PEC Objects for MFIE Formulation

  • Seo, Seung Mo
    • Journal of electromagnetic engineering and science
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    • v.19 no.1
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    • pp.6-12
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    • 2019
  • An IE-FFT algorithm is implemented and applied to the electromagnetic (EM) solution of perfect electric conducting (PEC) scattering problems. The solution of the method of moments (MoM), based on the magnetic field integral equation (MFIE), is obtained for PEC objects with closed surfaces. The IE-FFT algorithm uses a uniform Cartesian grid to apply a global fast Fourier transform (FFT), which leads to significantly reduce memory requirement and speed up CPU with an iterative solver. The IE-FFT algorithm utilizes two discretizations, one for the unknown induced surface current on the planar triangular patches of 3D arbitrary geometries and the other on a uniform Cartesian grid for interpolating the free-space Green's function. The uniform interpolation of the Green's functions allows for a global FFT for far-field interaction terms, and the near-field interaction terms should be adequately corrected. A 3D block-Toeplitz structure for the Lagrangian interpolation of the Green's function is proposed. The MFIE formulation with the IE-FFT algorithm, without the help of a preconditioner, is converged in certain iterations with a generalized minimal residual (GMRES) method. The complexity of the IE-FFT is found to be approximately $O(N^{1.5})$and $O(N^{1.5}logN)$ for memory requirements and CPU time, respectively.

Anti-corrosion impact of green synthesis of Silica nanoparticles for the sports structures in physical exercise activities

  • Zhixin Zhang;Zhiqiang Cai;Khidhair Jasim Mohammed;H. Elhosiny Ali
    • Advances in concrete construction
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    • v.15 no.1
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    • pp.41-46
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    • 2023
  • Sport has no age limit and can be done anywhere and in any condition with minimal equipment. The existence of sports spaces in all parts of the world is considered a citizen's right. One of the activities carried out in this field is installing sports equipment and structures in parks and encouraging citizens to use this equipment for physical health with the least cost and facilities. Installing sports structures in open spaces such as parks is a practical step for developing citizens' sports. Although using devices in parks is acceptable, it is more critical to meet scientific and technical standards. The components of these structures must have high strength and endurance against changes in environmental conditions such as humidity, temperature difference, and corrosion. Among the various causes of material degradation, corrosion has always been one of several fundamental causes of metal equipment failure. Sports structures in open spaces are not safe from corrosion. Uniform corrosion is the most common type of corrosion. This corrosion usually occurs uniformly through a chemical or electrochemical reaction across the surface exposed to the corrosive environment. Rust and corrosion of outdoor sports structures are examples of this corrosion. For this reason, in this research, with the green synthesis of silica nanoparticles and its application in outdoor sports structures, the life span of these structures can be increased for the use of physical exercises as well as their quality.

Environmental Changes Due to Planting Pine Trees on the Coastal Dunes Along the East Coast of Korea - Case Study of Osan Beach in Yangyang-gun - (곰솔 조림으로 인한 동해안 사구의 환경변화 - 양양군 오산해변을 사례로 -)

  • Choi, Kwang Hee;Kong, Hak-Yang
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.1
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    • pp.21-31
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    • 2020
  • Planting pine trees on the coastal dunes has been carried out along the East coast as well as West coast of South Korea. Although the artificial forestation has been regarded as a good policy that help to protect the coastal area from natural disasters, but its real effect to the landscapes is still unknown. In this study, we have installed a monitoring site with an automated weather station to study requirements for dune formation and its environmental changes in Osan beach, Yangyang-Gun, Gangwon Province. We analyzed the meteorological data collected from 2010 to 2019 and vegetational changes in the study area. As a result, the wind speed is decreased by around 30% and the pine-covered area is increased by around 300m2 after planting Japanese Black Pine in 2015. At present, it seems that the eolian transport of sand particle is minimal, because the dominant winds are the westerly winds which is not landward but seaward, and because the surface roughness length is about 0.5m which is similar to that in the deciduous forest.

A Study on 3D Virtual Clothing Fashion Design Applying Frank Stella Painting

  • Yeonji Lee;Sohee Um
    • Journal of Fashion Business
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    • v.27 no.6
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    • pp.1-17
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    • 2023
  • This study aimed to develop a modern textile design based on the formability of Frank Stella's paintings and to develop and present a fashion design that combines modern sensibility as a 3D virtual clothing program. The formative characteristics of Frank Stella's work were 'unity due to regular stripes', 'asymmetry due to geometric surface division', and 'decorabilitydue to colorful use'. Based on this, costume patterns and textiles based on Frank Stella's paintings were developed and six 3D virtual fashion design works were produced. The conclusion was as follows. First, it was confirmed that Frank Stella's work has a very wide range of applications to fashion products as abstract expression and minimal simplicity coexist visually. Second, various colors and forms of Frank Stella's paintings could be developed using textiles with visual formability, and originality as a fashion work applied with paintings could be maximized. Third, the development of 3D fashion using virtual programs had the ease of time efficiency, cost reduction, and spatiotemporal expansion of work processing compared to the actual costume production process. In addition, the simulation of 3D virtual wear made it easy to modify and recover the position of the textile to be applied to the costume and create a new design in the process of transforming the position of various textiles. It is expected that this study results will be used as basic data for the future conversion content industry in the painting and fashion industries.

Coherence Analysis of Jaw and Neck Muscle Coordination during Chewing in Healthy Adults

  • Ho-Jun Song;Sang-Ho Han;Ji-Yeon Kim;Yeong-Gwan Im
    • Journal of Oral Medicine and Pain
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    • v.48 no.4
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    • pp.159-168
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    • 2023
  • Purpose: Coordinated activity between the jaw and neck muscles is important in oral motor tasks such as chewing. This study examined coherence between the jaw and neck muscles during chewing in healthy adults. Methods: A total of 12 healthy adults underwent electromyography (EMG) of the jaw and neck muscles during right-sided chewing at a frequency of 1 Hz. Surface electrodes were placed over the temporalis (TA), masseter (MS), anterior digastric (DA), and sternocleidomastoid (SM) muscles on the right side. EMG signals were processed for coherence and phase analysis using advanced signal processing techniques. Results: The MS and TA muscle pair exhibited high synchronization when chewing (median coherence=0.992). Contrarily, the coherence values between the MS and DA, as well as the MS and SM muscle pairs, were relatively low (median coherence=0.848 and 0.957, respectively). Phase analysis revealed minimal temporal differences between the MS and TA muscle pair and the MS and SM muscle pair, whereas substantial phase shifts were observed between the MS and DA muscle pair. Conclusions: During chewing in healthy adults, the TA muscle works synergistically whereas the DA muscle antagonistically with the MS muscle, and the SM muscle supports the activity of the MS muscle. The observed synchrony and coordination provide insights into the intricate interplay among these muscles during oral motor tasks.