• Title/Summary/Keyword: Singular function

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Second Toe Plantar Free Flap for Volar Tissue Defects of the Fingers

  • Cho, Yong Jin;Roh, Si Young;Kim, Jin Soo;Lee, Dong Chul;Yang, Jae Won
    • Archives of Plastic Surgery
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    • v.40 no.3
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    • pp.226-231
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    • 2013
  • Background The reconstruction of volar surface defects is difficult because of the special histologic nature of the tissue involved. The plantar surface is the most homologous in shape and function and could be considered the most ideal of reconstructive options in select cases of volar surface defects. In this paper, we evaluate a single institutional case series of volar tissue defects managed with second toe plantar free flaps. Methods A single-institution retrospective review was performed on 12 cases of reconstruction using a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years) with a male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 cases) followed by amputations (3 cases) and a single case of burn injury. Half of the indications (6 cases) were for soft-tissue defects with the other half for scar contracture. Results All of the flaps survived through the follow-up period. Sensory recovery was related to the time interval between injury and reconstruction-with delayed operations portending worse outcomes. There were no postoperative complications in this series. Conclusions Flexion contracture is the key functional deficit of volar tissue defects. The second toe plantar free flap is the singular flap whose histology most closely matches those of the original volar tissue. In our experience, this flap is the superior reconstructive option within the specific indications dictated by the defect size and location.

Study on Security Framework using Security Quantitative Analysis for the Effective Multimedia Services to WLAN Mesh Network (무선랜 메쉬 네트워크에서의 효율적인 멀티미디어 서비스를 위한 보안 정량화 기반의 프레임워크 연구)

  • Shin, Myoung-Sub;Lim, Sun-Hee;Yi, Ok-Yeon;Lim, Jong-In
    • Journal of Broadcast Engineering
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    • v.13 no.2
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    • pp.261-273
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    • 2008
  • Multimedia service whose use is rapidly increasing supports effective services to convert and transmit multimedia data based on network speed, noise circumstance, terminal computation, and type of contents for satisfying QoS. For supporting information protection of multimedia service, it offers middle level of singular security service or security mechanism which is based on policy of service provider, depending on present terminal computation and type of contents. It can support security mechanism for more effective multimedia service, if we study security of application layer and network layer for supporting multimedia service. In this paper, we propose Multimedia security framework reflected on quantitative analysis of the WLAN(Wireless Local Area Network) mesh network security using the utility function in the level of the sorority, violation and addictive compensation model.

Movie Recommendation System based on Latent Factor Model (잠재요인 모델 기반 영화 추천 시스템)

  • Ma, Chen;Kim, Kang-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.125-134
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    • 2021
  • With the rapid development of the film industry, the number of films is significantly increasing and movie recommendation system can help user to predict the preferences of users based on their past behavior or feedback. This paper proposes a movie recommendation system based on the latent factor model with the adjustment of mean and bias in rating. Singular value decomposition is used to decompose the rating matrix and stochastic gradient descent is used to optimize the parameters for least-square loss function. And root mean square error is used to evaluate the performance of the proposed system. We implement the proposed system with Surprise package. The simulation results shows that root mean square error is 0.671 and the proposed system has good performance compared to other papers.

Intrinsic Enrichment of Moving Least Squares Finite Difference Method for Solving Elastic Crack Problems (탄성균열 해석을 위한 이동최소제곱 유한차분법의 내적확장)

  • Yoon, Young-Cheol;Lee, Sang-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.457-465
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    • 2009
  • This study presents a moving least squares (MLS) finite difference method for solving elastic crack problems with stress singularity at the crack tip. Near-tip functions are intrinsically employed in the MLS approximation to model near-tip field inducing singularity in stress field. employment of the functions does not lose the merit of the MLS Taylor polynomial approximation which approximates the derivatives of a function without actual differentiating process. In the formulation of crack problem, computational efficiency is considerably improved by taking the strong formulation instead of weak formulation involving time consuming numerical quadrature Difference equations are constructed on the nodes distributed in computational domain. Numerical experiments for crack problems show that the intrinsically enriched MLS finite difference method can sharply capture the singular behavior of near-tip stress and accurately evaluate stress intensity factors.

Feature Vector Extraction and Classification Performance Comparison According to Various Settings of Classifiers for Fault Detection and Classification of Induction Motor (유도 전동기의 고장 검출 및 분류를 위한 특징 벡터 추출과 분류기의 다양한 설정에 따른 분류 성능 비교)

  • Kang, Myeong-Su;Nguyen, Thu-Ngoc;Kim, Yong-Min;Kim, Cheol-Hong;Kim, Jong-Myon
    • The Journal of the Acoustical Society of Korea
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    • v.30 no.8
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    • pp.446-460
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    • 2011
  • The use of induction motors has been recently increasing with automation in aeronautical and automotive industries, and it playes a significant role. This has motivated that many researchers have studied on developing fault detection and classification systems of an induction motor in order to minimize economical damage caused by its fault. With this reason, this paper proposed feature vector extraction methods based on STE (short-time energy)+SVD (singular value decomposition) and DCT (discrete cosine transform)+SVD techniques to early detect and diagnose faults of induction motors, and classified faults of an induction motor into different types of them by using extracted features as inputs of BPNN (back propagation neural network) and multi-layer SVM (support vector machine). When BPNN and multi-lay SVM are used as classifiers for fault classification, there are many settings that affect classification performance: the number of input layers, the number of hidden layers and learning algorithms for BPNN, and standard deviation values of Gaussian radial basis function for multi-layer SVM. Therefore, this paper quantitatively simulated to find appropriate settings for those classifiers yielding higher classification performance than others.

The Discipline of the Dom-ino Frame and the Regulating Line - A Study of Le Corbusier's Villa La Roche-Jeanneret and Villa Stein-de Monzie - (르 꼬르뷔제 건축에서 돔-이노 프레임과 규준선의 기율 - 라 로쉬-잔느레 주택과 가르쉬 주택을 중심으로 -)

  • Pai, Hyung-Min;Hyun, Myung-Seok
    • Journal of architectural history
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    • v.12 no.1 s.33
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    • pp.25-41
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    • 2003
  • This paper is a study of Le Corbusier's trace regulateur of the 1920s, particularly its role in the design of the Villas La Roche-Jeanneret and Stein-de Monzie. It proceeds on the basis of the following three themes: first, the relation between the regulating line and the dom-ino frame; second, its status as a proportional device based not on a module system but one that defines relations; third, its function as an essential practical device in the design process. In the Villa La Roche-Jeanneret, the embedded horizontal planes of the dom-ino frame were constant, but the vortical lines of the columns were altered according to the changes in plan. Initially, a left-hand bay window formed a symmetry with the right-hand bay window, the only constant in the design process. With subsequent changes, mullion sections of the horizontal window and roof elements came to provide the reference points for the regulating line. Eventually, a regulating line different from the one that controlled the bay window and the elongated volume came to control the entrance hall of Villa La Roche, resulting in three different kinds of regulating lines in the final version. In contrast to the Villa La Roche-Jeanneret, a singular and consistent regulation line was anticipated in the earliest design stages of the Villa Stein-de Monzie. The repetition of its A:B grid and the standard $2.5m{\times}1.0m$ sliding window determined the proportions of both its plan and elevation, and thus the regulating line became 'automatic,' losing its viability as a practical tool. Though the regulating titles of the La Roche-Jeanneret look as if they were an afterthought, drawn after the design was complete, they were most active, requiring tenacity and discipline in their application. On the other hand, the seemingly 'redundant' regulating line of the Villa Stein-de Monzie gains its raison d'etre from the dom-ino frame. Its cantilevers and uninterrupted horizontal window could be used in decisive fashion because of the guarantee that the correct proportion would always be maintained. Thus we discover that Le Corbusier's discipline of the 1920s had a certain spectrum of flexibility. His 'parti' ranged from the extremely loose and malleable grid of the Villa La Roche-Jeanneret to the fixed grid of the Villa Stein-de Monzie. In different ways, these projects retain the tension between the dom-ino frame and the regulating line. For Le Corbusier, as much as the grid was an object with fixed attributes, it was also an active medium manipulated by the will of the architect.

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Modified S-FPZ Model for a Running Crack in Concrete (콘크리트의 연속적인 균열성장에 대한 수정 특이-파괴진행대 이론)

  • Yon, Jung-Heum
    • Journal of the Korea Concrete Institute
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    • v.15 no.6
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    • pp.802-810
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    • 2003
  • In this paper, the modified singular fracture process zone (S-FPZ) model is proposed to consider variation of a fracture criterion for continuous crack propagation in concrete. The fracture properties of the proposed fracture model are strain energy release rate at a micro-crack tip and crack closure stress (CCS) versus crack opening displacement (COD) relationship in the FPZ. The proposed model can simulate the estimated fracture energy of experimental results. The analysis results of the experimental data shows that specimen geometry and loading condition did not affect the CCS-COD relation. But the strain energy release rate is a function of not only specimen geometry but also crack extension. Until 25 mm crack extension, the strain energy release rate is a constant minimum value, and then it increased linearly to the maximum value. The maximum fracture criterion occurred at the peak load for an large size specimen. The fracture criterion remains the maximum value after the peak load. The variation of the fracture criterion is caused by micro-cracking and micro-crack localizing. The fracture criterion of strain energy release rate can simply be the size effect of concrete fracture, and it can be used to quantify the micro-tracking and micro-crack localizing behaviors of concrete.

A Numerical Solution Method of the Boundary Integral Equation -Axisymmetric Flow- (경계적분방정식의 수치해법 -축대칭 유동-)

  • Chang-Gu,Kang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.3
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    • pp.38-46
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    • 1990
  • A numerical solution method of the boundary integral equation for axisymmetric potential flows is presented. Those are represented by ring source and ring vorticity distribution. Strengths of ring source and ring vorticity are approximated by linear functions of a parameter $\zeta$ on a segment. The geometry of the body is represented by a cubic B-spline. Limiting integral expressions as the field point tends to the surface having ring source and ring vorticity distribution are derived upto the order of ${\zeta}ln{\zeta}$. In numerical calculations, the principal value integrals over the adjacent segments cancel each other exactly. Thus the singular part proportional to $\(\frac{1}{\zeta}\)$ can be subtracted off in the calculation of the induced velocity by singularities. And the terms proportional to $ln{\zeta}$ and ${\zeta}ln{\zeta}$ can be integrated analytically. Thus those are subtracted off in the numerical calculations and the numerical value obtained from the analytic integrations for $ln{\zeta}$ and ${\zeta}ln{\zeta}$ are added to the induced velocity. The four point Gaussian Quadrature formula was used to evaluate the higher order terms than ${\zeta}ln{\zeta}$ in the integration over the adjacent segments to the field points and the integral over the segments off the field points. The root mean square errors, $E_2$, are examined as a function of the number of nodes to determine convergence rates. The convergence rate of this method approaches 2.

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Analysis of Interface Problem using the MLS Difference Method with Interface Condition Embedment (계면경계조건이 매입된 이동최소제곱 차분법을 이용한 계면경계문제 해석)

  • Yoon, Young-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.4
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    • pp.215-222
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    • 2019
  • The heat conduction problem with discontinuous material coefficients generally consists of the conservative equation, boundary condition, and interface condition, which should be additionally satisfied in the solution procedure. This feature often makes the development of new numerical schemes difficult as it induces a layered singularity in the solution fields; thus, a special approximation is required to capture the singular behavior. In addition to the approximation, the construction of a total system of equations is challenging. In this study, a wedge function is devised for enriching the approximation, and the interface condition itself is embedded in the moving least squares(MLS) derivative approximation to consistently satisfy the interface condition. The heat conduction problem is then discretized in a strong form using the developed derivative approximation, which is named as the interface immersed MLS difference method. This method is able to efficiently provide a numerical solution for such interface problems avoiding both numerical quadrature as well as extra difference equations related to the interface condition enforcement. Numerical experiments proved that the developed numerical method was highly accurate and computationally efficient at solving the heat conduction problem with interfacial jump as well as the problem with a geometrically induced interfacial singularity.

If This Brand Were a Person, or Anthropomorphism of Brands Through Packaging Stories (가설품패시인(假设品牌是人), 혹통과고사포장장품패의인화(或通过故事包装将品牌拟人化))

  • Kniazeva, Maria;Belk, Russell W.
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.3
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    • pp.231-238
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    • 2010
  • The anthropomorphism of brands, defined as seeing human beings in brands (Puzakova, Kwak, and Rosereto, 2008) is the focus of this study. Specifically, the research objective is to understand the ways in which brands are rendered humanlike. By analyzing consumer readings of stories found on food product packages we intend to show how marketers and consumers humanize a spectrum of brands and create meanings. Our research question considers the possibility that a single brand may host multiple or single meanings, associations, and personalities for different consumers. We start by highlighting the theoretical and practical significance of our research, explain why we turn our attention to packages as vehicles of brand meaning transfer, then describe our qualitative methodology, discuss findings, and conclude with a discussion of managerial implications and directions for future studies. The study was designed to directly expose consumers to potential vehicles of brand meaning transfer and then engage these consumers in free verbal reflections on their perceived meanings. Specifically, we asked participants to read non-nutritional stories on selected branded food packages, in order to elicit data about received meanings. Packaging has yet to receive due attention in consumer research (Hine, 1995). Until now, attention has focused solely on its utilitarian function and has generated a body of research that has explored the impact of nutritional information and claims on consumer perceptions of products (e.g., Loureiro, McCluskey and Mittelhammer, 2002; Mazis and Raymond, 1997; Nayga, Lipinski and Savur, 1998; Wansik, 2003). An exception is a recent study that turns its attention to non-nutritional packaging narratives and treats them as cultural productions and vehicles for mythologizing the brand (Kniazeva and Belk, 2007). The next step in this stream of research is to explore how such mythologizing activity affects brand personality perception and how these perceptions relate to consumers. These are the questions that our study aimed to address. We used in-depth interviews to help overcome the limitations of quantitative studies. Our convenience sample was formed with the objective of providing demographic and psychographic diversity in order to elicit variations in consumer reflections to food packaging stories. Our informants represent middle-class residents of the US and do not exhibit extreme alternative lifestyles described by Thompson as "cultural creatives" (2004). Nine people were individually interviewed on their food consumption preferences and behavior. Participants were asked to have a look at the twelve displayed food product packages and read all the textual information on the package, after which we continued with questions that focused on the consumer interpretations of the reading material (Scott and Batra, 2003). On average, each participant reflected on 4-5 packages. Our in-depth interviews lasted one to one and a half hours each. The interviews were tape recorded and transcribed, providing 140 pages of text. The products came from local grocery stores on the West Coast of the US and represented a basic range of food product categories, including snacks, canned foods, cereals, baby foods, and tea. The data were analyzed using procedures for developing grounded theory delineated by Strauss and Corbin (1998). As a result, our study does not support the notion of one brand/one personality as assumed by prior work. Thus, we reveal multiple brand personalities peacefully cohabiting in the same brand as seen by different consumers, despite marketer attempts to create more singular brand personalities. We extend Fournier's (1998) proposition, that one's life projects shape the intensity and nature of brand relationships. We find that these life projects also affect perceived brand personifications and meanings. While Fournier provides a conceptual framework that links together consumers’ life themes (Mick and Buhl, 1992) and relational roles assigned to anthropomorphized brands, we find that consumer life projects mold both the ways in which brands are rendered humanlike and the ways in which brands connect to consumers' existential concerns. We find two modes through which brands are anthropomorphized by our participants. First, brand personalities are created by seeing them through perceived demographic, psychographic, and social characteristics that are to some degree shared by consumers. Second, brands in our study further relate to consumers' existential concerns by either being blended with consumer personalities in order to connect to them (the brand as a friend, a family member, a next door neighbor) or by distancing themselves from the brand personalities and estranging them (the brand as a used car salesman, a "bunch of executives.") By focusing on food product packages, we illuminate a very specific, widely-used, but little-researched vehicle of marketing communication: brand storytelling. Recent work that has approached packages as mythmakers, finds it increasingly challenging for marketers to produce textual stories that link the personalities of products to the personalities of those consuming them, and suggests that "a multiplicity of building material for creating desired consumer myths is what a postmodern consumer arguably needs" (Kniazeva and Belk, 2007). Used as vehicles for storytelling, food packages can exploit both rational and emotional approaches, offering consumers either a "lecture" or "drama" (Randazzo, 2006), myths (Kniazeva and Belk, 2007; Holt, 2004; Thompson, 2004), or meanings (McCracken, 2005) as necessary building blocks for anthropomorphizing their brands. The craft of giving birth to brand personalities is in the hands of writers/marketers and in the minds of readers/consumers who individually and sometimes idiosyncratically put a meaningful human face on a brand.