• Title/Summary/Keyword: first fundamental form

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TRANSLATION SURFACES OF TYPE 2 IN THE THREE DIMENSIONAL SIMPLY ISOTROPIC SPACE 𝕀13

  • Bukcu, Bahaddin;Karacan, Murat Kemal;Yoon, Dae Won
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.3
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    • pp.953-965
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    • 2017
  • In this paper, we classify translation surfaces of Type 2 in the three dimensional simply isotropic space ${\mathbb{I}}_3^1$ satisfying some algebraic equations in terms of the coordinate functions and the Laplacian operators with respect to the first, the second and the third fundamental form of the surface. We also give explicit forms of these surfaces.

A Study on an Effective Higher-Order Taylor-Galerkin Method for the Analysis of Structural Dynamics (동적 해석을 위한 효과적 고차 Taylor Galerkin법에 관한 연구)

  • 윤성기;박상훈
    • Journal of KSNVE
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    • v.3 no.4
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    • pp.353-359
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    • 1993
  • In this study, the Taylor-Galerkin method is modified to take into consideration the third order term in the Taylor series of the fundamental variable. In the Taylor-Galerkin method, after expressing the governing equation of motion in conservation form, the temporal discretization is done first and then spatial discretization follows in contrast to the conventional approaches. A predictor-corrector type algorithm has been developed previously by the same author. A new computationally efficient direct algorithm is proposed in this study. A study on convergency and accuracy of the solution is carried out. Numerical examples show that this new algorithm exhibits the same order of accuracy with less computational effort.

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The Emotional Dimensions of North Korean Politics through the Lens of Historical Institutionalism

  • Kim, Hwajung
    • Journal of Contemporary Eastern Asia
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    • v.21 no.2
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    • pp.13-26
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    • 2022
  • This study explores the following research question to address issues linked to emotions, identity, and institutions: how has the cult (institution) of the three Kims affected North Koreans' strong sense of nationalism (emotion), which is based on their Juche ideology (identity)? This paper investigates four fundamental elements of historical institutionalism: time boundedness, path dependency, institutional changes, and the shadow of the past. First, time boundedness illustrates how culture and education have been used to build trust and loyalty in the general public to construct individual and family cults. Second, path dependence reveals how the Songbun system has resulted in strong nationalism throughout Rodongdang's institutionalization. Third, institutional changes highlight the significance of age divides, as different age groups do not always support the three Kims' cult. Finally, the shadow of the past helps us understand the primary processes for generating mass ardent nationalism in the form of powerful impulses for self-sacrifice.

ROTATIONAL HYPERSURFACES CONSTRUCTED BY DOUBLE ROTATION IN FIVE DIMENSIONAL EUCLIDEAN SPACE 𝔼5

  • Erhan Guler
    • Honam Mathematical Journal
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    • v.45 no.4
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    • pp.585-597
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    • 2023
  • We introduce the rotational hypersurface x = x(u, v, s, t) constructed by double rotation in five dimensional Euclidean space 𝔼5. We reveal the first and the second fundamental form matrices, Gauss map, shape operator matrix of x. Additionally, defining the i-th curvatures of any hypersurface via Cayley-Hamilton theorem, we compute the curvatures of the rotational hypersurface x. We give some relations of the mean and Gauss-Kronecker curvatures of x. In addition, we reveal Δx=𝓐x, where 𝓐 is the 5 × 5 matrix in 𝔼5.

Somatometric Characteristics on Upper Body of Elementary School Girls -Focusing somatometric factors- (학령기 여아의 상반신 체형특성-체형구성인자를 중심으로-)

  • 장정아;배은아;권영숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.6
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    • pp.850-860
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    • 2000
  • The purposes of this study was to provide the fundamental data for children's wear standardizing sizes of ready-made clothes by analyzing the elementary school girls’somatotype. The subjects for anthropometic measurements were 434 elementary school girls’by age groups < ‘(1st age(1ㆍ2 grade)’,‘2nd age(3ㆍ4 grade)’, and 3rd(5ㆍ6 grade)’ > living in Pusan. According to the analysis of upper bodies by the age groups 1. According to the analysis to draw somatometric factors by the age groups, sevenㆍseven and six actors in 1st . End and 3rd age groups are obtained from measurements of upper body. 2. The 1st & 2nd age groups: As the result of factor analysis for the factor, the first and second factors which explain more than 70% of the whole variance represent“horizontal size”and“vertical size”, which characterize more aspects of the body shape of girls at elementary school ages. 3. The 3rd age groups: As the result of factor analysis for the factor, 6 factor which explain 74.39% of variance were extracted form anthropometic data. The first factor represented the items of circumference, breadth and depth related to“sectional size the front length of the upper body”, The second factor described the items of "heights & the back length of the upper body”.

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Trend of Dispute on the Right to Be Forgotten and Acceptance Task of Internet Laws in Korea (잊혀질 권리의 논의 동향과 우리나라 인터넷 법제의 수용과제)

  • Chung, Sang-Ki;Kim, Kyung-Yeol
    • Journal of Information Technology Services
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    • v.12 no.1
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    • pp.131-141
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    • 2013
  • Matters related to the right to be forgotten started the dispute Europe to introduce it first when Data Protection Directive established in 1995 proceeded revision. Relating to this, diverse disputes proceed on responding to personal information protection and internet laws in our nation. Especially as our National Assembly submitted the law regarding the promotion of information and communication network use and protection of information and amendment of copyright, it is necessary to look into the movement on introduction of law of right to be forgotten closely in detail. EU which attempted the institutionalization for the first time, relating to review of General Data Protection Regulation, proposed opinions such as the necessity to define subjects of personal information concretely and specifically and or protection target and balanced consideration on freedom of expression which is constitutional value. In the case of our nation, there was legislation attempt to introduce the regulation but it was limited in the form of fallen effectiveness without concrete and detailed review on internet law. To solve such problems, it is necessary to look into issues and matters to be considered required to accept right to be forgotten closely and discuss possibility of introducing right to be forgotten, conflicts between fundamental rights becoming issue, effect of goal achievement of personal information protection through the system introduction, and other rational acceptance method.

First-principles Study on the Formation of Solid-Electrolyte Interphase on the LiMn2O4 Cathode in Li-Ion Batteries (제일원리 전산모사를 통한 리튬 이온 전지의 LiMn2O4 전극-전해질 계면 반응 분석)

  • Choe, Dae-Hyeon;Gang, Jun-Hui;Han, Byeong-Chan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.97-97
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    • 2016
  • Development of advanced Li-ion battery cells with high durability is critical for safe operation, especially in applications to electric vehicles and portable electronic devices. Understanding fundamental mechanism on the formation of a solid-electrolyte interphase (SEI) layer, which plays a substantial role in the electrochemical stability of the Li-ion battery, in a cathode was rarely reported unlike in an anode. Using first-principles density functional theory (DFT) calculations and ab-initio molecular dynamic (AIMD) simulations we demonstrate atomic-level process on the generation of the SEI layer at the interface of a carbonate-based electrolyte and a spinel $LiMn_2O_4$ cathode. To accomplish the object we calculate the energy band alignment between the work function of the cathode and frontier orbitals of the electrolyte. We figure out that a proton abstraction from the carbonate-based electrolyte is a critical step for the initiation of an SEI layer formation. Our results can provide a design concept for stable Li-ion batteries by optimizing electrolytes to form proper SEI layers.

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Curve Tracing Algorithm for Surface/Surface Intersection Curves in 3D Geomtric Modeling (3차원 기하 모델링에서 곡면간의 교차곡선 추적 알고리즘)

  • Park, Chul-Ho;Hong, Sung-Soo;Sim, Je-Hong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.8
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    • pp.2163-2172
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    • 1997
  • SSI(Surface/Surface Intersection)is a fundamental geometric operation which is used in solid and geometric modeling to support trimmed surface and Boolean operations. In this paper, we suggest a new algorithm for tracing along the intersection curve of two regular surfaces. Thus, in this paper, we present a simplicity of computing and second degree continunity. Given a point of intersection curve, it is traced to entire curve of a intersection curve as the initial point of its and the initial point of each of a intersection curve is detected to DFS(Depth First Search) method in the Quadtree and is naturally presented a continuous form.

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The Classification of Foot Types of Junior High School Boys for the Development of Shoes' Easy-Order Prototype (신발류 이지오더 Prototype 개발을 위한 청소년의 발의 형태 분류)

  • Lim, Ji-Young;Choi, Sung-Won
    • Fashion & Textile Research Journal
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    • v.7 no.5
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    • pp.535-541
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    • 2005
  • The health of feet is connected with individual's health and affects a man's activity. Shoes need to be designed to protect feet and to absorb the impact of land. In order to choose suitable shoes for feet, the foot size and shape must be considered, so it is essential to grasp the exact size and shape of the foot. This study aims to present fundamental data on shoes' easy order prototype development for choosing shoes of good wearing comfort, by classifying feet size and shape junior high school boys in the early adolescent period. The subject were 234 Korean junior high school boys age from 14 to 16 years old. The subjects were directly measured anthropometrically and indirectly analyzed photographically. 6 factors were extracted through factor analysis and those factors comprised 79.42% of total variance. The factors characterizing foot girth and width, foot length, foot height, foot shape around the fifth toes, angle of foot breadth and foot shape around the first toes. 3 clusters as their foot shape were categorized using 6 factor scores by cluster analysis. Type 1 was characterized by long large foot with deformed first toe. Type 2 had smaller in foot girth, width and length than other types and with deformed fifth toe. Type 3 had average size and high foot shape. Shoes prototype which is to be developed later on will be able to generate 2D flattening in the foot sole form. Therefore, it would be a great support in producing and choosing appropriate shoes if forms are classified by subdividing foot form classification and extract a factor which shows only the foot sole shape.

The Vegetation Characteristics of Small Palustrine Wetland in Rural Area (농촌지역 소규모 소택형습지의 식생특성)

  • Kang, Bang Hun;Son, Jin-Kwan;Lee, Sang-Hwa;Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.3
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    • pp.33-48
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    • 2009
  • A palustrine wetland is a type of a wetland that prevails in Korea as well as an ecosystem that provides various ecological functions and has affluent biodiversity. This study was conducted to understand the characteristics of vegetation in a palustrine wetland by analyzing a life form and naturalized plants, in order to present the maintenance and utilization plan of a small wetland. A total of 249 taxa including 76 families, 188 generics, 209 species, 38 varieties and 2 forma were found at six investigated wetlands. As a result of the appearance ratio analysis, Therophytes (37.8%) with 94 taxa and Hemicryptophytes (31.3%) with 78 taxa were in order of life form, and Gramineae (14.1 %) with 35 taxa and Compositae (11.2 %) with 28 taxa were in order of family level. These were deemed representative vegetation in a palustrine wetland. Equosetum arvense, Phragmites communis, Commelina communis, Persicaria thunbergii, Arenaria serpyllifolia, Stellaria media, Erigeron annuus, Erigeron canadensis and Artemisia princeps var, orientalis were found continuously for a period of investigation in all sites. Equosetum arvense, Phragmites communis and Persicaria thunbergii were species with high appearance frequency. Especially, Persicaria thunbergii was construed high in a cover ratio in May as it develop first among Hydrophytes and form a canopy sooner than anything else. We found that a degree of naturalization and an urbanization index appear comparatively high in Yeongok-ri, Cheonan, Gangjang-ri, Asan and Yodang-ri, Hwasung, which is construed due to artificial interference, such as fanning, fishing, swimming and green-tour program. These results would be used to utilize in restoring a deserted and damaged wetland and to provide fundamental data in creating a wetland as follows.