• Title/Summary/Keyword: fundamental principles

Search Result 366, Processing Time 0.032 seconds

Nano Scale Compositional Analysis by Atom Probe Tomography: I. Fundamental Principles and Instruments (Atom Probe Tomography를 이용한 나노 스케일의 조성분석: I. 이론과 설비)

  • Jung, Woo-Young;Bang, Chan-Woo;Gu, Gil-Ho;Park, Chan-Gyung
    • Applied Microscopy
    • /
    • v.41 no.2
    • /
    • pp.81-88
    • /
    • 2011
  • Even though importance of nano-scale structure and compositional analysis have been getting increased, existing analysis tools have been reached to their limitations. Recent development of Atom Probe Tomography (APT), providing 3-dimensional elemental distribution and compositional information with sub-nm scale special resolution and tens of ppm detection limit, is one of key technique which can overcome these limitations. However, due to the fact that APT is not well known yet in the domestic research area, it has been rarely utilized so far. Therefore, in this article, the theoretical background of APT was briefly introduced with sample preparation to help understanding APT analysis.

Design and Implementation of Educational problem solving game (교육용 문제 풀기 게임 설계 및 구현)

  • Seo, Jeong-Man
    • Journal of the Korea Society of Computer and Information
    • /
    • v.15 no.2
    • /
    • pp.83-89
    • /
    • 2010
  • The reality is that existing games are commercial or violent rather than informative. So, such a phenomenon resulted in many social problems. To solve such problems, I designed and implemented a game which is not violent but educative and child-friendly. In this thesis, an educative game is defined and its characteristics are described. I designed the user interface of the game for children, proposed relevant algorithms, and showed resultant screens of the game. Also, I compared the game with the existing games in order to prove that my game is non-violent, non-commercial, and rather educative. This ladder rejection game is different from the existing game in terms of design, functions, and contents of the screen. This paper contains specific explanations about the supplemented ladder rejection game. First, the design of this ladder rejection game extended fundamental principles of the existing game and added new diverse functions.

Korean Status and Prospects for Radioactive Waste Management

  • Song, M.J.
    • Journal of Nuclear Fuel Cycle and Waste Technology
    • /
    • v.1 no.1
    • /
    • pp.1-7
    • /
    • 2013
  • The safe management of radioactive waste is a national task required for sustainable generation of nuclear power and for energy self-reliance in Korea. Since the initial introduction of nuclear power to Korea in 1978, rapid growth in nuclear power has been achieved. This large nuclear power generation program has produced a significant amount of radioactive waste, both low- and intermediate-level waste (LILW) and spent nuclear fuel (SNF); and the amount of waste is steadily growing. For the management of LILW, the Wolsong LILW Disposal Center, which has a final waste disposal capacity of 800,000 drums, is under construction, and is expected to be completed by June 2014. Korean policy about how to manage the SNF has not yet been decided. In 2004, the Atomic Energy Commission decided that a national policy for SNF management should be established considering both technological development and public consensus. Currently, SNF is being stored at reactor sites under the responsibility of plant operator. The at-reactor SNF storage capacity will run out starting in 2024. In this paper, the fundamental principles and steps for implementation of a Korean policy for national radioactive waste management are introduced. Korean practices and prospects regarding radioactive waste management are also summarized, with a focus on strategy for policy-making on SNF management.

Analytical solutions for crack initiation on floor-strata interface during mining

  • Zhao, Chongbin
    • Geomechanics and Engineering
    • /
    • v.8 no.2
    • /
    • pp.237-255
    • /
    • 2015
  • From the related engineering principles, analytical solutions for horizontal crack initiation and propagation on a coal panel floor-underlying strata interface due to coal panel excavation are derived in this paper. Two important concepts, namely the critical panel width of horizontal crack initiation on the panel floor-underlying strata interface and the critical panel width of vertical fracture (crack) initiation in the panel floor, have been presented. The resulting analytical solution indicates that: (1) the first criterion can be used to express the condition under which horizontal plane cracks (on the panel floor-underlying strata interface or in the panel floor because of delamination) due to the mining induced vertical stress will initiate and propagate; (2) the second criterion can be used to express the condition under which vertical plane cracks (in the panel floor) due to the mining induced horizontal stress will initiate and propagate; (3) this orthogonal set of horizontal and vertical plane cracks, once formed, will provide the necessary weak network for the flow of gas to inrush into the panel. Two characteristic equations are given to quantitatively estimate both the critical panel width of vertical fracture initiation in the panel floor and the critical panel width of horizontal crack initiation on the interface between the panel floor and its underlying strata. The significance of this study is to provide not only some theoretical bases for understanding the fundamental mechanism of a longwall floor gas inrush problem but also a benchmark solution for verifying any numerical methods that are used to deal with this kind of gas inrush problem.

Clinical Applications of Intracoronary OCT (Invited Paper) (심혈관 OCT의 임상적 응용)

  • Ha, Jinyong;Kim, Jung-Sun;Hong, Myeong-Ki
    • Korean Journal of Optics and Photonics
    • /
    • v.26 no.1
    • /
    • pp.1-8
    • /
    • 2015
  • The most common cause of a heart attack is known as coronary artery disease, which narrows the arteries and reduces the blood flow to the heart. To treat coronary artery stenosis, percutaneous coronary intervention (PCI) (a nonsurgical procedure to install a stent, which holds the artery wall open) is performed. Intracoronary optical coherence tomography (OCT) is a catheter-based, invasive optical imaging system. To determine whether PCI is appropriate, and to perform stent evaluation in a catheterization laboratory, OCT examinations are carried out. This review details the fundamental principles and technological status of intracoronary OCT imaging, and discusses the ongoing clinical applications to determine the benefits of OCT-guided PCI.

An Efficient Ways of Improving Regulations on Insider Trading (내부자거래(內部者去來) 규제개선(規制改善)의 효율적(效率的)인 방안(方案))

  • Park Sang-Bong
    • Management & Information Systems Review
    • /
    • v.4
    • /
    • pp.611-629
    • /
    • 2000
  • In the legislation interpretation and fundamental viewpoint about the legal system of insider trading, Japan strictly legislate under the proposition, the principle of 'nulla poena,' adopted 'the principle of limited enumeration,' and United states, under 'the principle of comprehension,' has entrusted courts with establishment of concrete concepts and standard, so the courts are very flexible in determining the range of insiders and the importance of inside information to show a strong will to eradicate insider trading. Korea has a legislative position of 'the principle of limited indication' which has been created by the negotiation between those principles of United states and Japan. Though this court has interpreted insider trading, insider trading using non-disclosed information has increased lately, needing the strengthening of its regulations. However, this shows us that sophisticate the regulations may be, the exposure of insider trading has limitations. The most important thing is to change recognition for transparency of the securities market, security of investors and to establish the atmosphere which is that fair stock trading made in a sound capital market to raise funds for corporation. The policies of improving unfair trading, self-regulation bodies, raising the transparency and legality of procedures of supervision and monitoring and applying 'compliance program' to stock companies are very needed to eliminate unfair trading in the securities market and establish the order of trading.

  • PDF

A Study on the Modern Understanding of Filial Piety: Based on the Its Education (효의 현대적 이해에 관한 연구: 효 교육을 중심으로)

  • 임희규
    • Journal of Families and Better Life
    • /
    • v.17 no.3
    • /
    • pp.229-240
    • /
    • 1999
  • The purpose of this study is to find out the essence and the meaning of conventional filial piety and its education to be a help to build up a moral society. Consequently the main point of this study is grafting our filial piety to industrial society and reviewing our conventional filial piety at the present time and what is the role of education. The traditional thought of our people is based on the filial piety and it is based on the basic love in humanity that is is rooted in the principle of benevolence. We should realize the most important practical principles of reverent affection. Our traditional filial piety has been handed down along with long history. though it has been a little chaned to meet the needs of the times. We should not forget that the fundamental thought of filial piety has never changed. The education for filial piety in modern society should be taken charge of by family society and school and be helped each other So the filial piety thought as tradition l ethics has to be adjusted to the modern sense. We should make a considerable point of the filial piety education for value which will bring about the recovery of humanity.

  • PDF

Principles and Applications in Multileaf Collimator for Radiation Therapy (방사선치료에 있어서 Multileaf Collimator의 원리와 그 응용)

  • Chung, Kap-Soo
    • Journal of radiological science and technology
    • /
    • v.21 no.1
    • /
    • pp.24-28
    • /
    • 1998
  • A conventional treatment machine shapes x-ray fields by a set of dense metal collimators(jaws) built into the machine. These collimators are positioned by the therapist using hand controls in the treatment room, and usually remain stationary during treatment. The collimator jaws of treatment machines produce rectangular beams. Conventional beam shaping is accomplished through the use of a combination of these collimator jaws and secondary custom beam blocks attached to the accelerator beyond the collimator Jaws. The jaw positions for a particular field can be retrieved from a computer. One application of this increased capability is replacement of beam blocks for field-shaping with the MLC. There are three basic applications of the MLC. The first application is to replace conventional blocking. A second function of the MLC is related to conformal therapy, adjusting the field shape to match the beam's eye view projection of a planning target volume during treatment. The third application is the use of the MLC to achieve beam intensity modulation. The aim of this paper is to provide basic principle and to state fundamental concepts needed to implement the use of a multileaf collimator in the conventional clinical setting. The use of MLC field shaping is likely to save time and to incur a lower operating cost when compared to the use of beam blocks.

  • PDF

Community Design Model for Remote Rural Settlements - Focused on the Mountain Community in Less Favored Area - (정주공간 구성을 위한 커뮤니티설계 모형 연구 - 조건불리지역 산촌을 중심으로 -)

  • 유병림;황기원
    • Journal of Korean Society of Rural Planning
    • /
    • v.2 no.2
    • /
    • pp.67-80
    • /
    • 1996
  • Less Favored Area(LFA) is a newly shaped regional concept and just appearing as a new community design target, where the topogeographical, industry-locational condition and the daily living environment have been outstandingly inferior to any other regions. Community Design(CD) principles that cover a spatial order of settlements are introduced in this study when the CD concept is applied to the LFA. The study puts a great stress on the horizontal and vertical order of communal spatial units and living activities oriented to residents'socio-economic activities, on which a CD district and an inner spatial organization of community is based. Therefore the various relationships between residents' activities and particular places, such as that between agricultural production and land, access to living services and community-outer settlements, is analysed through the field study. The emphatic point is that the spatial unit and organization of community, namely settlement order is casted not only by the horizontal coverage but also by the vertical hierarchy forming a cubic-like spatial order. Applying the CD idea to LFA has limit because the CD has been oriented on urban architectural style and community participation process. Nevertheless, that has a new possibility to understand the fundamental and archetypical change of a spatial pattern of community uncovering the accumulated layer of settlement order especially in the drastically changed mountain community from past to now.

  • PDF

Predictive Study of Hysteretic Rubber Friction Based on Multiscale Analysis (멀티스케일 해석을 통한 히스테리시스 고무 마찰 예측 연구)

  • Nam, Seungkuk;Oh, Yumrak;Jeon, Seonghee
    • Tribology and Lubricants
    • /
    • v.30 no.6
    • /
    • pp.378-383
    • /
    • 2014
  • This study predicts the of the hysteretic friction of a rubber block sliding on an SMA asphalt road. The friction of filled rubber on a rough surface is primarily determined by two elements:the viscoelasticity of the rubber and the multi-scale perspective asperities of the road. The surface asperities of the substrate exert osillating forces on the rubber surface leading to energy dissipation via the internal friction of the rubber when rubber slides on a hard and rough substrate. This study defines the power spectra at different length scales by using a high-resolution surface profilometer, and uses rubber and road surface samples to conduct friction tests. I consider in detail the case when the substrate surface has a self affine fractal structure. The theory developed by Persson is applied to describe these tests through comparison with the hysteretic friction coefficient relevant to the energy dissipation of the viscoelastic rubber attributable to cyclic deformation. The results showed differences in the absolute values of predicted and measured friction, but with high correlation between these values. Hence, the friction prediction model is an appropriate tool for separating the effects of each factor. Therefore, this model will contribute to clearer understanding of the fundamental principles of rubber friction.