• Title/Summary/Keyword: core idea

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Studies on the Acoustical Characteristics of Violin Bridges and SDM Simulation (바이올린 브릿지의 음향적 특성 및 SDM 시뮬레이션에 관한 연구)

  • 정우양
    • Journal of the Korea Furniture Society
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    • v.12 no.1
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    • pp.47-55
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    • 2001
  • Violin bridge blank cut from maple wood with good quality has typical pattern of the radial direction in the side edge with minimal dispersion. This experimental study was designed and carried out to examine the effect of the physical and macroscopical characteristics on the compressive creep of violin bridge blank which had been imported from European manufacturer. This research arose from the idea that the maple solid wood with heterogeneous wood density and ray direction in the side edge would have uneven rheological property of violin bridge blank which is supposed to be pressed by the tension of strings. Experimentally, the compressive creep of bridge blank became smaller with the higher density of imported maple wood and showed clear density-dependence for the duration of load under the string tension of 5 kgf. Every bridge blank showed the behavior of primary creep stage(stress stabilization) having logarithmic regression creep curve with high correlation coefficient under the designed stress level. Even though the relationship between compressive creep and ray direction on the side edge of bridge was not so clear contrary to expectation, we could conclude that wood density and ray direction should be the quality decisive factors affecting the acoustical characteristics and performance of the bridge, the core member of violin-family bow instruments.

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A Study on the Teaching of 'a Concept of Fraction as Division($b{\div}a=\frac{b}{a}$)' in Elementary Math Education - Based on a Analysis of the Korean Successive Elementary Math Textbooks (초등수학에서 '나눗셈으로서의 분수($b{\div}a=\frac{b}{a}$)' 개념 지도에 관한 연구 - 한국의 역대 초등수학 교과서에 대한 분석을 중심으로)

  • Kang, Heung Kyu
    • Journal of Elementary Mathematics Education in Korea
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    • v.18 no.3
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    • pp.425-439
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    • 2014
  • The concept of a fraction as division is a core idea which serves as a axiom in the process of a extension of the natural number system to rational number system. Also, it has necessary position in elementary mathematics. Nevertheless, the timing and method of the introduction of this concept in Korean elementary math textbooks is not well established. In this thesis, I suggested a solution of a various topics which is related to this problem, that is, transforming improper fraction to mixed number, the usage of quotient as a term, explaining the algorithm of division of fraction, transforming fraction to decimal.

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A Study on Methodology for Strategy Development of ASP Service: A Case Study of Small Company Informatization (ASP 서비스의 전략개발방법론에 관한 연구: 기업 네트워크화 사례)

  • Hong, Jong-Yi;Lee, Yun-Mi;Suh, Eui-Ho
    • Asia pacific journal of information systems
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    • v.16 no.3
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    • pp.177-192
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    • 2006
  • Following the idea of "what you measure is what you get," this paper discusses the necessity to improve the plan and management of Application Service Provider (ASP) service based on performance evaluation. The Balanced Scorecard (BSC) has been used as a tool for suggesting the measures that can evaluate performance of a company by considering both financial and non-financial perspectives. The current BSC does not provide techniques to formally define, verify, implement and analyze the performance measures of ASP. Therefore, we developed a methodology for strategy development of ASP service by analyzing the BSC performance measures. This methodology provides a strategy for improving ASP service. The methodology proposed in this paper provide executives with core parts for achieving vision as well as the corresponding interpretation model for developing strategy. The methodology consists of the following two phases: BSC and Importance-Performance Analysis (IPA) phase. The methodology is illustrated through a case study in each phase. The case study shows practical deployment of our methodology.

Cybercrime as a Discourse of Interpretations: the Semantics of Speech Silence vs Psychological Motivation for Actual Trouble

  • Matveev, Vitaliy;Eduardivna, Nykytchenko Olena;Stefanova, Nataliia;Khrypko, Svitlana;Ishchuk, Alla;PASKO, Katerina
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.203-211
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    • 2021
  • The article studies the discourse and a legal uncertainty of the popular and generally understandable concept of cybercrime. The authors reveal the doctrinal approaches to the definition of cybercrime, cyberspace, computer crime. The analysis of international legal acts and legislation of Ukraine in fighting cybercrime is carried out. The conclusion is made about the need to improve national legislation and establish international cooperation to develop the tools for countering cybercrime and minimizing its negative outcomes. The phenomenon of nicknames is studied as a semantic source, which potentially generates a number of threats and troubles - the crisis of traditional anthroponymic culture, identity crisis, hidden sociality, and indefinite institutionalization, incognito style, a range of manifestations of loneliness - from voluntary solitude to traumatic isolation and forced detachment. The core idea is that it is the phenomenon of incognito and hidden name (nickname and other alternatives) that is the motivational stimulus for the fact of information trouble or crime.

New Fault Current Fast Shutdown Scheme for Buck Converter (벅 컨버터의 새로운 고장전류 고속차단 기법)

  • Park, Tae-Sik;Kim, Seong-Hwan
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.68-73
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    • 2019
  • This paper presents a novel fast shut-down scheme for Buck converter by using a coupled inductor. Generally, a controller for Buck converter stops generating PWM patterns in various fault cases: Overcurrent, Short circuit, or Overvoltage, but the inductor and capacitor keep supplying their stored energy to loads although the switching operations in Buck converter stopped. The stored energy in the inductor and capacitor could cause electrical stresses on breakers and safety problems. The main idea of the proposed fast shutdown scheme is to demagnetize the inductor core by using a coupled inductor, and its performance and operations are verified by using PSIM Simulation.

Existential Ideas in Wright's Notion of Nature (라이트의 자연관 속의 실존적 사고)

  • Lee, Jae-Young
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.4
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    • pp.95-102
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    • 2018
  • In this study, existential thoughts in Frank Lloyd Wright's notion of nature were investigated. Wright, a modern architect, presented the idea of creating organic architecture in harmony with nature. His naturalistic romanticism is considered to be the original inspiration for his concept of organic architecture. However, his understanding of architecture in harmony with nature stems from existential ideas in his notion of nature, including humanity. The proposed study analyzes his existential beliefs through his speeches and writings in four categories-love of nature, thoughts of abstract and concrete, nature as being intrinsic and "becoming," and thoughts on science and art. Our analyses reveal that, on the one hand, Wright was inspired by thoughts of naturalistic romanticism born from his disillusionment with city life and an urge to seek life in nature, while, on the other, he also believed that real nature is intrinsic to humans and manifests itself in the very core of their being. He sought to unite humanity, as the interior of nature, with its physical environment, as the exterior of nature. His notion of nature is a "becoming" one that changes with time and space, and varies based on individual humans. In line with these thoughts, Wright sought to create forms not only with respect to mathematical dimensions, but also in consideration of human significance. He considered art and architecture to be born out of an integral thought as a process of humanization. To him, nature is interpreted by humans.

An Analysis of The Kindergarten-elementary School Transition Policy from The New Perspective of "Bidirectional Articulation"

  • Xueyao Wang;Zhangpei Li
    • Journal of the International Relations & Interdisciplinary Education
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    • v.2 no.2
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    • pp.1-8
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    • 2022
  • In March 2021, the <Guidance on Promoting the Scientific Interface between Kindergarten and Elementary School> issued by the Ministry of Education of China clearly pointed out that it is necessary to adhere to child oriented. This goal of this policy is based on the idea of "living education" proposed by Mr. Heqin Chen in 1940, which indicates that a true understanding of children is necessary before talking about educating them. The core goal of "bidirectional articulation" is to strengthen the sense of articulation between kindergartens and elementary school, scientifically prepare for and adapt to school enrollment, and promote the smooth transition of children. Moreover, the <Guidance Points for Kindergarten Readiness Education> and the <Guidance Points for Elementary School Adaptation Education>, which were released at the same time as the <Guidance on Promoting the Scientific Interface between Kindergarten and Elementary School>, also place special emphasis on the cultivation of children's life preparation and adaptability. The aim of the bidirectional articulation "bridging" is to realize a two-way exchange of curriculum between kindergarten and elementary school, and to reform the curriculum at three levels through the curriculum spirit of "gamification", the continuous curriculum structure, and the developmental curriculum evaluation.

Development of a Competency-Based Assessment Framework for High School Home Economics (고등학교 가정과의 역량 기반 평가 프레임워크 개발)

  • Young Sun Choi;Mi Jeong Park
    • Human Ecology Research
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    • v.62 no.2
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    • pp.197-216
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    • 2024
  • The dual aims of this study were i) to explore the effectiveness of an assessment method that can measure the competencies learned through high school home economics and ii) develop a competency-based assessment framework for high school home economics, including components of competency-based assessment, item development system, and other elements. The study involved the following stages: literature analysis, draft development, concretization, validity verification, and final version. Based on the results of the literature analysis and expert deliberation, a competency-based assessment framework for high school home economics was developed which comprised three dimensions: 'core idea' × 'process' × 'context and value'. Based on this, an item analysis table was presented to systematize various activities for the competency-based assessment of high school home economics, following which a holistic rubric suitable for competency assessment tasks was proposed by referring to the newly developed 'process' dimension assessment criteria. This study is significant in that it is the first to propose a competency-based assessment framework that systematically presents a variety of assessment activities. These will facilitate the development of assessment standards and tools that teachers can refer to or trust in the changing school environment due to the introduction of the standard-based assessment system based on a high school credit system, and the guarantee of a minimum achievement level.

Enhanced data-driven simulation of non-stationary winds using DPOD based coherence matrix decomposition

  • Liyuan Cao;Jiahao Lu;Chunxiang Li
    • Wind and Structures
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    • v.39 no.2
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    • pp.125-140
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    • 2024
  • The simulation of non-stationary wind velocity is particularly crucial for the wind resistant design of slender structures. Recently, some data-driven simulation methods have received much attention due to their straightforwardness. However, as the number of simulation points increases, it will face efficiency issues. Under such a background, in this paper, a time-varying coherence matrix decomposition method based on Diagonal Proper Orthogonal Decomposition (DPOD) interpolation is proposed for the data-driven simulation of non-stationary wind velocity based on S-transform (ST). Its core idea is to use coherence matrix decomposition instead of the decomposition of the measured time-frequency power spectrum matrix based on ST. The decomposition result of the time-varying coherence matrix is relatively smooth, so DPOD interpolation can be introduced to accelerate its decomposition, and the DPOD interpolation technology is extended to the simulation based on measured wind velocity. The numerical experiment has shown that the reconstruction results of coherence matrix interpolation are consistent with the target values, and the interpolation calculation efficiency is higher than that of the coherence matrix time-frequency interpolation method and the coherence matrix POD interpolation method. Compared to existing data-driven simulation methods, it addresses the efficiency issue in simulations where the number of Cholesky decompositions increases with the increase of simulation points, significantly enhancing the efficiency of simulating multivariate non-stationary wind velocities. Meanwhile, the simulation data preserved the time-frequency characteristics of the measured wind velocity well.

Engineering Geological Implications of Fault Zone in Deep Drill Cores: Microtextural Characterization of Pseudotachylite and Seismic Activity (시추코어 단층대에서의 지질공학적 의미: 슈도타킬라이트의 미세조직의 특징과 지진활동)

  • Choo, Chang-Oh;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.27 no.4
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    • pp.489-500
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    • 2017
  • It is not rare that pseudotachylite, dark colored rock with glassy texture, is recognizable in deep core samples drilled up to 900 m from the surface. Pseudotachylite with widths varying few to 20 cm is sharply contacted or interlayered with the host rocks composed of Jurassic granite and Precambrian amphibolite gneiss, showing moderately ductile deformation or slight folding. Pseudotachylite occurring at varying depths in the deep drill core are slightly different in texture and thickness. There is evidence of fault gouge at shallower depths, although brittle deformation is pervasive in most drill cores and pseudotachylite is identified at random depth intervals. Under scanning electron microscope (SEM), it is evident that the surface of pseudotachylite is characterized by a smooth, glassy matrix even at micrometer scale and there is little residual fragments in the glass matrix except microcrystals of quartz with embayed shape. Such textural evidence strongly supports the idea that the pseudotachylite was generated through the friction melting related to strong seismic events. Based on X-ray diffraction (XRD) quantitative analysis, it consists of primary minerals such as quartz, feldspars, biotite, amphibole and secondary minerals including clay minerals, calcite and glassy materials. Such mineralogical features of fractured materials including pseudotachylite indicate that the fractured zone might form at low temperatures possibly below $300^{\circ}C$, which implies that the seismic activity related to the formation of pseudotachylite took place at shallow depths, possibly at most 10 km. Identification and characterization of pseudotachylite provide insight into a better understanding of the paleoseismic activity of deep grounds and fundamental information on the stability of candidate disposal sites for high-level radioactive waste.