• 제목/요약/키워드: A first principles study

Search Result 822, Processing Time 0.029 seconds

SYMMETRY AND MONOTONICITY OF SOLUTIONS TO FRACTIONAL ELLIPTIC AND PARABOLIC EQUATIONS

  • Zeng, Fanqi
    • Journal of the Korean Mathematical Society
    • /
    • v.58 no.4
    • /
    • pp.1001-1017
    • /
    • 2021
  • In this paper, we first apply parabolic inequalities and a maximum principle to give a new proof for symmetry and monotonicity of solutions to fractional elliptic equations with gradient term by the method of moving planes. Under the condition of suitable initial value, by maximum principles for the fractional parabolic equations, we obtain symmetry and monotonicity of positive solutions for each finite time to nonlinear fractional parabolic equations in a bounded domain and the whole space. More generally, if bounded domain is a ball, then we show that the solution is radially symmetric and monotone decreasing about the origin for each finite time. We firmly believe that parabolic inequalities and a maximum principle introduced here can be conveniently applied to study a variety of nonlocal elliptic and parabolic problems with more general operators and more general nonlinearities.

Formative characteristics of 3D printing fashion from the perspective of mechanic aesthetic (기계 미학적 관점에서 살펴본 3D Printing 패션의 조형적 특성)

  • Kim, Young-Sam;Lee, Jin-Ah;Kim, Jang-Hyeon;Jun, Yuh-Sun
    • The Research Journal of the Costume Culture
    • /
    • v.23 no.2
    • /
    • pp.294-309
    • /
    • 2015
  • This study aims to clarify the aesthetic values between emotion of human and expression of technology in contemporary fashion as it analyzes formative characteristics of related cases in fashion based on principles of 3D Printing technology and the viewpoint of mechanic aesthetics. The conclusions of this study are as follows. First, 3D Printing fashion is not only expressed diverse variations by its principles of formative methods, materials and properties, but also changes of silhouette by applying system of designers. Second, general characteristics of 3D Printing fashion is represented by various applications in SLS system, and it can be specifically explained application to a portion of clothing, decorative roles of clothing, complicated pattern making through crossing fabrics using 3D scanner and displaying a certain object changing fashion styles, and so forth. Third, the formative characteristics of 3D Printing fashion from the perspective of mechanic aesthetics is as follows. It can be analyzed as the integration of metaphysical values through compared symbolization of natural feature and technical evolution, partial dynamics and interactive velocity-based, formative combinations for abstract expression using architectural components, cosmos images and substantialized structures through images of organic space interacted human shapes. As the mention above, 3D Printing technology can creative a diverse area of fashion, and express images of new technological fashion through various works with continuous development of techniques.

A Study on Application of MC Design Standardization Standard and Current Status in Ga-Yang Modular Housing (가양 모듈러 실증단지의 MC설계표준화 기준 적용 및 실태조사 연구)

  • Lim, Seok-Ho;Chung, Joon-Soo;Seol, Wook-Je;Baek, Cheong-Hoon
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.35 no.5
    • /
    • pp.85-94
    • /
    • 2019
  • The modular apartment has been completed for the first time in Korea through the national research and development (R&D) project in December 2017, and 30 households moved in. Although conditions such as technicality and constructability have to be satisfied to adopt and spread the modular apartments in the future, economic feasibility is the most important factor among the conditions. The economic feasibility of modular apartments can be compared with that of existing reinforced concrete (RC) structure apartments. It is highly important to reduce the construction cost through standardization above all. The standardization refers to establishment of national design standards and principles, and it is important for manufacturers and building companies to comply with those standards and principles. The modular construction (MC) skill in Korea is at an early adoption stage and the MC market is not widely expanded yet. Thus, the application of the MC design, which is the basis of the standardization, has not been widely accepted. However, related R&D projects are now performing mainly by the Ministry of Land, Infrastructure, and Transport to promote modular apartments in recent years and the design standardization standard (draft) is now prepared to be notified as a result of the steady research. Furthermore, pilot complexes for demonstration purpose are under construction, starting from public rental apartments. Thus, MC method-applied public rental houses will be spread in near future. This study aims to investigate the current design status in the Ga-Yang Housing as a pilot modular complex to produce and supply more economical and efficient modular houses, and analyze the problems by comparing the design standardization standards with pre-notified design standardization standards and summarize the modifications between them thereby presenting foundational data for establishment of the design standardization in the modular business industry.

Necessary to reconsider the recognize of the disuniting of organizations holding intangible cultural assets. - From the viewpoint of Yangjubyeolsandae-nori - (무형문화재 보유단체 분열에 대한 인식(認識)의 재고(再考)를 요(要)함 -양주별산대놀이 사례 중심-)

  • Jeon, Pil-seub
    • (The) Research of the performance art and culture
    • /
    • no.43
    • /
    • pp.405-440
    • /
    • 2021
  • The members of the holding group 'YangjuByeolsandae-nori' (National Important Intangible Cultural Heritage) were divided into two groups in 2010. This means that the internal groupwhich has been going on since the previous period exploded. The subject of the researchis to deal with thedisruption. The first purpose of the research is to record the cause·deployment·ending of the 'YangjuByeolsandaeTalnori'. The second purpose of the research is to reviewthe appropriateness of the administrative measures taken by the Cultural Heritage Administrationin intervention. The thirdpurpose of the research the Cultural Heritage Administration's contribution to the establishment of principles to cope with group disruption. The fourth purpose of the researchis to serve as a reference to the resolution of the disruption of other preservation groups. The result of the research suggests that the administration should recognize that the conflict of the ownership over the group must be resolved in order to boost the overall success of the project, and must establish and respond to the principles. The content is a reconstruction of the explanation. To deal with divisions is also considered to be a field of study. The research which deals directly with the main researcher's problems is put forward in hopes of contributing to the study and contributing to society.

A theoretical study on Ti:LiNbO3 integrated optical polarization mode controllers (Ti:LiNbO3 집적광학형 편광모드 조절기의 이론적 고찰)

  • 문제영;정홍식;이한영
    • Korean Journal of Optics and Photonics
    • /
    • v.15 no.2
    • /
    • pp.142-148
    • /
    • 2004
  • We investigated a Ti:LiNbO$_3$ based integrated-optic polarization controller with a Ti-indiffused waveguide along the z-axis utilizing the electro-optic effect. The device consists of a first quarter-wave (λ/4) phase-shifter followed by a half-wave(λ/2) and a second quarter-wave(λ/4) wave-plate, which is rotated synchronously with the first quarter-wave phase-shifter. We analyzed the operation principles of the device utilizing cascaded transfer matrices based on Jones matrix and Poincare sphere, simulated driving voltages for various input states of polarization (SOP), and theoretically confirmed transformations from any arbitrary input SOP into any general output SOP.

Process for the Architectural Application of Biomimicry (생체모방의 건축적 적용을 위한 프로세스)

  • Kim, Jong-Moo;Kang, Chul-Hee;Yoon, Heakyung
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.34 no.12
    • /
    • pp.77-84
    • /
    • 2018
  • Biomimicry architecture has been highlighted in recent years for the innovative ideas from the nature have provided main developments in many areas. The related studies in Korean architecture is entering the first step and are needed close attentions for its vitalizations. This study starts with the acknowledgement of necessity to establish the architectural application process. First of all, it is named as a 'Passive Cycle' if a problem-solving or a project has been through the analysis of process complexity and biomimicry application process in other areas. Then, the basic frame is structured as a 'Process-Cooperation,' which integrates process complexation with process circulation. The cooperative relationship starts from the beginning of the design with not only professionalists related with architecture but also ones in various areas when it is issued a difficult problem or high environmental performance not found in common architectural design processes. To make the architectural application good progress, the characteristics of bio-mimetic architectural applications are categorized as three areas; the expected effect, the application level, and application method. As a result, the organic complexity should be prioritized to have bio-mimetic application effectively while accessing the principles. Therefore, the process for the architectural application of biomimicry is suggested as 'Organic Cycle-Cooperation.'

METALLIC INTERFACES IN HARSH CHEMO-MECHANICAL ENVIRONMENTS

  • Yildiz, Bilge;Nikiforova, Anna;Yip, Sidney
    • Nuclear Engineering and Technology
    • /
    • v.41 no.1
    • /
    • pp.21-38
    • /
    • 2009
  • The use of multi scale modeling concepts and simulation techniques to study the destabilization of an ultrathin layer of oxide interface between a metal substrate and the surrounding environment is considered. Of particular interest are chemo-mechanical behavior of this interface in the context of a molecular-level description of stress corrosion cracking. Motivated by our previous molecular dynamics simulations of unit processes in materials strength and toughness, we examine the challenges of dealing with chemical reactivity on an equal footing with mechanical deformation, (a) understanding electron transfer processes using first-principles methods, (b) modeling cation transport and associated charged defect migration kinetics, and (c) simulation of pit nucleation and intergranular deformation to initiate the breakdown of the oxide interlayer. These problems illustrate a level of multi-scale complexity that would be practically impossible to attack by other means; they also point to a perspective framework that could guide future research in the broad computational science community.

Development of magnetism in armchair graphene nanoribbons with edge functionalizations: A first-principles study

  • Shin, Dongjae;Kim, Yong-Hoon
    • Proceeding of EDISON Challenge
    • /
    • 2017.03a
    • /
    • pp.376-382
    • /
    • 2017
  • Graphene nanoribbons with zigzag-shaped edge (zGNRs) are predicted to be magnetic insulator at the ground state, attracting significant interest in view of spintronic applications [1]. On the other hand, although they are energetically and thermodynamically more favored than zGNRs [2], graphene nanoribbons with armchair-shaped edge (aGNRs) have been less spotlighted than zGNRs due to the absence of magnetism. Herein, based on the combined density functional theory (DFT) and matrix Green's function (MGF) approach, we consider aGNRs functionalized with various molecular groups, and show that the spin polarizations develop for some of the considered aGNR edge functionalization cases. The origin of the induced magnetism will be discussed within the Lieb's theorem [3]. This work will provide a novel guidance for the development of graphene-based spintronic devices.

  • PDF

A new mindlin FG plate model incorporating microstructure and surface energy effects

  • Mahmoud, F.F.;Shaat, M.
    • Structural Engineering and Mechanics
    • /
    • v.53 no.1
    • /
    • pp.105-130
    • /
    • 2015
  • In this paper, the classical continuum mechanics is adopted and modified to be consistent with the unique behavior of micro/nano solids. At first, some kinematical principles are discussed to illustrate the effect of the discrete nature of the microstructure of micro/nano solids. The fundamental equations and relations of the modified couple stress theory are derived to illustrate the microstructural effects on nanostructures. Moreover, the effect of the material surface energy is incorporated into the modified continuum theory. Due to the reduced coordination of the surface atoms a residual stress field, namely surface pretension, is generated in the bulk structure of the continuum. The essential kinematical and kinetically relations of nano-continuums are derived and discussed. These essential relations are used to derive a size-dependent model for Mindlin functionally graded (FG) nano-plates. An analytical solution is derived to show the feasibility of the proposed size-dependent model. A parametric study is provided to express the effect of surface parameters and the effect of the microstructure couple stress on the bending behavior of a simply supported FG nano plate.

The Development of Classification System of Medical Procedures in Korea (한국표준의료행위 분류체계 개발)

  • Park, Hyoung-Wook;Sohn, Myong-Sei;Kim, Han-Joong;Park, Eun-Cheol;Yu, Seung-Hum
    • Journal of Preventive Medicine and Public Health
    • /
    • v.29 no.4 s.55
    • /
    • pp.877-897
    • /
    • 1996
  • In recent years, the Korean Medical Association has undertaken the feat of establishing the Korean Standard Terminology of Medical Procedures with the dedicated help of 32 medical academic societies. However, because the project is being conducted by several different circles, it has yet to see a clear system of classification. This thesis, therefore, proposes the three principles of scientific properties, usefulness and ideology as the basis for classification system and has developed the Classification System of Medical Procedures in Korea upon their foundation. The methodology and organization of this thesis as follows. First, by adopting scientific classification system of Feinstein(1988), an analysis of the classification systems of the medical procedures in the United States, Japan, Taiwan, WHO was carried out to reveal the framework and the basic principles in each system. Second, the direction of classification system has been constructed by applying the normative principle of medical field in order to show the future direction of the medical field and realize its ideology. Third, a finalized framework for the classification system will be presented as based on the direction of classification system. Of the three basis principles mentioned above, the analysis on the principles of usefulness was left out of this thesis due to the difficulty of establishing specific standards of analysis. The results of the study are as follows. The overall structure of the thesis is aimed at showing the 'Prevention-Therapy-Rehabilitation' quality of comprehensive health care and consists of six chapters; I. Prevention and Health Promotion II. Evaluation and Management III. Diagnostic Procedures IV. Endoscopy V. Therapeutic Procedures VI. Rehabilitation Chapter three Diagnostic Procedures is divided into four parts : Functional Diagnosis, Visual Diagnosis, Pathological Diagnosis, Biopsy and Sampling. Chapter five Therapeutic Procedures is divided into Psychiatry, Non-Invasive Therapy, Invasive Therapy, Anaesthesia and Radiation Oncology. Of these sub-divisions, Functional Diagnosis, Biopsy and Sampling, Endoscopy and Invasive Therapy employs the anatomical system of classification. On the other hand, Visual Diagnosis, Pathological Diagnosis, Anesthesia and Diagnostic Radiology, namely those divisions in which there is little or no overlapping in services with other divisions, used the classification system of its own division. The classification system introduced in this thesis can be further supplemented through the use of the cluster analysis by incorporating the advice and assistance of other specialists.

  • PDF