• Title/Summary/Keyword: Essential Elements

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Automated Finite Element Mesh Generation for Integrated Structural Systems (통합 구조 시스템의 유한요소망 형성의 자동화)

  • Yoon, Chongyul
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.2
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    • pp.77-82
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    • 2023
  • The structural analysis module is an essential part of any integrated structural system. Diverse integrated systems today require, from the analysis module, efficient real-time responses to real-time input such as earthquake signals, extreme weather-related forces, and man-made accidents. An integrated system may also be for the entire life span of a civil structure conceived during the initial conception, developed throughout various design stages, effectively used in construction, and utilized during usage and maintenance. All these integrated systems' essential part is the structural analysis module, which must be automated and computationally efficient so that responses may be almost immediate. The finite element method is often used for structural analysis, and for automation, many effective finite element meshes must be automatically generated for a given analysis. A computationally efficient finite element mesh generation scheme based on the r-h method of mesh refinement using strain deviations from the values at the Gauss points as error estimates from the previous mesh is described. Shape factors are used to sort out overly distorted elements. A standard cantilever beam analyzed by four-node plane stress elements is used as an example to show the effectiveness of the automated algorithm for a time-domain dynamic analysis. Although recent developments in computer hardware and software have made many new applications in integrated structural systems possible, structural analysis still needs to be executed efficiently in real-time. The algorithm applies to diverse integrated systems, including nonlinear analyses and general dynamic problems in earthquake engineering.

Effect of Heavy Metals on the Secretion of Amylase in Rat Pancreatic Fragments (중금속류가 취절편의 Amylase 분비에 미치는 영향)

  • Kim, Hea-Young;Kim, Won-Joon
    • The Korean Journal of Pharmacology
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    • v.17 no.2
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    • pp.31-36
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    • 1981
  • Heavy metals which are present as trace elements in human body have been known to modify various enzymatic reaction. These metals can be essential or non-essential. Zinc, copper and calcium are essential in maintaining some biological processes, whereas non-essential metals such as cadmium, lead and mercury produce accumulatve toxic effect. Cadmium accumulated in pancreas can cause toxicity and damage of pancreatic cells, thereby influencing CHO metabolism. Lead compounds are known to produce toxic effects on the kidney, digestive system and brain fellowed by inhibition of activity of ${\rho}-aminolevulinic$ acid and biosynthesis of hemoproteins and cytochrome. Evidence has been accumulated that zinc not only acts as a cofactor in enzyme reaction but also prevents toxic effect induced by heavy metal such as copper and cadmium. To demonstrate the effect of heavy metals on pancreatic secretion, part of uncinate pancreas was taken and incubated in Krebs-Ringer bicarbonate buffer with heavy metals used. Additional treatment with CCK-OP was performed when needed. After incubation during different period of time, medium was analyzed for amylase activity using Bernfeld's method. The present study was attempted in order to elucidate the effect of several kinds of heavy metal on exocrine pancreatic secretion in vitro. The results obtained are as follows: 1) CCK-OP stimulated significantly amylase release from pancreatic fragments in vitro. 2) CCK-OP response of amylase release from pancreatic fragments was inhibited by treatmant with cadmium, especially high doses of cadmium. 3) CCK-OP response of amylase release from pancreatic fragments was inhibited when pretreated with $10^{-4}M$ copper chloride. 4) Lead chloride at the concentration of $10^{-3}M\;and\;10^{4}M$ stimulated the basal amylase release in vitro but CCK-OP response did not augment by lead chloride. 5) Zine chloride did not affect amylase release from pancreatic fragment in vitro. From the results mentioned above, it is suggested that CCK-OP response was inhibited it the amylase release from pancreatic fragments pretreated with cadmium and copper chloride.

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Chemical Properties of Major Tree Barks in Korea -(I) Chemical Composition of Reducing Sugars and Five Essential Elements- (한국산(韓國産) 주요(主要) 수종(樹種) 수피(樹皮)의 화학적(化學的) 성질(性質) -(I) 일반분석(一般分析), 환원당구성(構成), 무기원소(無機元素)-)

  • Lee, Hwa Hyoung
    • Journal of Korean Society of Forest Science
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    • v.40 no.1
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    • pp.63-69
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    • 1978
  • A bark comprises about 10 to 20 percents of a typical log by volume, and is generally considered as an unwanted residue rather than a potential1y valuable resourses, As the world has been confronted with decreasing forest resources, natural resources pressure dictate that a bark should be a raw material instead of a waste. The utilization of the largely wasted bark of genus Pinus, Quercus, and Populus grown in Korea can be enhanced by learning their chemical properties. However, the chemical study of tree bark grown in korea have never been undertaken. In the present paper, the studies on the chemical properties of bark comprise carbohydrates, lignin, and extractives, composition of reducing sugars and five essential elements. The results may be summarized as follows: 1. Bark are much richer in quantity of lignin and extractives than the corresponding wood, and are chiefly consisted of lignin, extractives and carbohydrates orderly. It is the same with ash contents. Alcohol-benzene extractives of populus bark are the highest among three genus. 2. Although glucose constitutes the major sugar in both pine and hardwoods bark, in pinus, arabinose and xylose are the next but in hard woods, the next is xylose. 3. Essential elements, Ca and Kjeldahl-N are higher in the bark than in the wood. Ca content is the highest among others, and N,K followed it. Essential elements are higher in Quercus than in Populus and pinus.

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A Study on Developing Metadata Elements and Database of the Science Information for Youth (청소년 과학정보 메타데이터 요소 및 데이터베이스 구축 연구)

  • Kwak, Seung-Jin
    • Journal of the Korean Society for Library and Information Science
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    • v.38 no.1
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    • pp.263-279
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    • 2004
  • This study intends to design a metadata service system of the science information for youth on the web based on the efficiency of the metadata system. Metadata scheme of the science information for youth on the web has been developed and designed metadata collection on the basis of the previously designed classification system. Metadata scheme of the science information for youth, which is consisted of six essential elements and four additional elements, has been brought out, compared to not only Dublin Core Metadata Element Set, but also the main studies related to domestic and foreign metadata projects. Based on the results of it, metadata database of the science information has been designed and it is expected to be applicable to metadata service system of the science information for youth on the web.

A Study on Classification of Teaching-Learning Materials in Mathematics Using Computers (교수-학습 자료 분류 체계화 연구 - 수학 교과 분류체계를 중심으로 -)

  • 황혜정;신항균
    • School Mathematics
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    • v.6 no.1
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    • pp.91-118
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    • 2004
  • Since 1998 year, many educational software and its contents have been developed by individuals and public institutes. However, it is not easy to re-use the contents effectively and consistently, because they should be changed and reorganized whenever a curriculum is changed. Therefore, it is important for each subject to establish new system in which the contents or their teaching-learning elements are not changed although new curriculum appears. In this respect, in last year(2003 year), while setting mathematics as a representative subject, KERIS executed a study on developing a system(or method) of classifying teaching-learning materials in mathematics using computers, based on future-oriented curriculum including the current mathematics curriculum. Finally, for this study, the most essential and basic teaching-teaming 'units' were developed and the total number of units were 339. Also, in addition to the development of 'units', the 'elements' were developed for understanding more concrete contents included in each 'unit' and the total number of elements were 1191.

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Development of an Object-oriented Finite Element Model through Iterative Method Ensuring Independency of Elements (요소 독립성이 유지되는 반복해법에 의한 객체지향 유한요소모델 개발)

  • Lee, Han-Ki;Kim, Tae-Gon;Lee, Jeong-Jae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.2
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    • pp.115-125
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    • 2012
  • Application of the Object-oriented Programming (OOP) method to the Finite Element Model (FEM) program has various strengths including the features of encapsulation, polymorphism and inheritance. However, this technique should be based upon a premise that the independency of the object method and data to be used is guaranteed. By attempting to apply the OOP to the FEM, existing researches go against the independency of the OOP which is an essential feature of the method. The reason is this: existing researches apply the OOP to modules in accordance with analysis procedures, although the data to be used is classified as an element unit in the FEM. Therefore, the required independency cannot be maintained as whole stiffness matrices and boundary conditions are combined together. Also, solutions are sought from analysis module after data is regrouped at the pre-processor, and their results are analyzed during the post-processor. As this is similar to a batch processing, it cannot use data at analysis, and recalculation should be done from the beginning if any condition is changed after the analysis is complete, which are limitations of the existing researches. This research implemented the Object-orientation of elements so that the three features of the OOP (i.e. encapsulation, polymorphism and inheritance) can be guaranteed and their independency maintained as a result. For this purpose, a model called 'Object-oriented Finite element Model ensuring the Independency of Elements (OFMIE)', which enables the analysis of targets through mutual data exchanges within instance, was developed. In conclusion, the required independency was achieved in the instance of the objected elements and the analysis results of previous conditions could be used for the analysis after changes. The number of repetitive calculations was reduced by 75 per cent through this gradual analysis processes.

An Analysis and Evaluation of Urban Landscapes Using Images Taken with a Fish-eye Lens (천공사진(天空寫眞)을 이용한 도시경관의 분석 및 평가)

  • Han Gab-Soo;Yoon Young-Hwal;Jo Hyun-Kil
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.11-21
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    • 2005
  • The purpose of this study was to analyze and evaluate landscape characteristics by classification of landscapes in Chuncheon. A system was developed to convert images taken with a fish-eye lens to panoramic pictures. Landscape characteristics were analyzed by appearance rate and area distribution rate of landscape elements on panorama picture. Landscape characteristics were analyzed according to the number of times landscape elements appeared and the amount of area that each element occupied in the panoramic picture. Each panoramic picture was classified into five types based on these landscape element factors. Landscape evaluation was carried out using dynamic images converted from picture by fish-eye lens. The results of this study can be summarized as follows. The urban landscape can be characterized by four essential factors: interconnectedness, nature, urban centrality and landscape scale. Five types of landscapes were determined: detached residential building landscape (type 1), street landscape with various elements (type 2), street landscape in the center of a city (type 3), landscape of housing complex (type 4), and landscape of green space (type 5). Type 5 had the highest degree of landscape satisfaction and the landscape satisfaction increased with the number of appearances of natural elements. The amount of peen space had a high relation with a landscape satisfaction.

A Study on Metadata Elements for Acquiring E-mail Record in Public Agency (공공기관의 이메일 기록 획득을 위한 메타데이터 요소 연구)

  • Suh, Yun-Ju;Jung, Suk-Kwon
    • Journal of the Korean Society for information Management
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    • v.26 no.1
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    • pp.125-145
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    • 2009
  • E-mail became the universal communication means today that is widely used socially. It is being used as an important communication means in a problem about interchange and commerce with foreign countries as well as exchange of opinions within public agency and in relationship with other institution, corporation or organization. Also, in the trend of pointing to digital government, e-mail is becoming the primary means of contacting with the people. However, our country is not recognizing e-mail as official record yet, and is not offering any guideline for managing e-mail. E-mail is one form in electronic record, and needs to be acquired and managed as record given having been used for public service. It is essential to prescribe meta-data elements necessary for acquisition and management. Accordingly, the final purpose of this study is to offer the foundation in the e-mail record management of our country, by suggesting meta-data elements that will need to be secured when acquiring e-mail record.

PNN based Rogers Diagnosis Method for Fault Classification of Oil-filled Power Transformer (유입변압기 고장분류를 위한 PNN 기반 Rogers 진단기법 개발)

  • Lim, Jae-Yoon;Lee, Dae-Jong;Ji, Pyeong-Shik
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.4
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    • pp.280-284
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    • 2016
  • Stability and reliability of a power system in many respects depend on the condition of power transformers. Essential devices as power transformers are in a transmission and distribution system. Being one of the most expensive and important elements, a power transformer is a highly essential element, whose failures and damage may cause the outage of a power system. To detect the power transformer faults, dissolved gas analysis (DGA) is a widely-used method because of its high sensitivity to small amount of electrical faults. Among the various diagnosis methods, Rogers diagonsis method has been widely used in transformer in service. But this method cannot offer accurate diagnosis for all the faults. This paper proposes a fault diagnosis method of oil-filled power transformers using PNN(Probability Neural Network) based Rogers diagnosis method. The test result show better performance than conventional Rogers diagnosis method.

A Study on the Cases of Seller's Fundamental Breach (근본적(根本的) 계약위반(契約違反) 조항(條項)의 적용(適用) 사례(事例)에 관한 고찰(考察) - 매도인(賣渡人)의 의무위반(義務違反)을 중심(中心)으로-)

  • Ha, Kang-Hun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.19
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    • pp.67-93
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    • 2003
  • The CISG approach was intended to make the remedial system clear, but produced ambiguity, and complexity. The CISG does not differentiate between main, auxiliary and participatory obligations. There is no distinction between breaches of main or breaches of auxiliary obligations, rather, a distinction is made between fundamental and other breaches of contract. Articles 25 gives the definition of fundamental breach of contract. This concept is the essential of avoidance and remedial system in the CISG. This concept, however, is ambiguous. The fact that the fundamentality of a breach of contract in many cases is the condition for an avoidance of contract, is expression of the trend of the CISG to preserve contracts, which I consider as essential in international trade. The elements which define a substantial detriment are extremely complex. It will become obvious that the relevant detriment is not a static element, but in many instances occurs only when the breach of contract continues. It should be added that it is the circumstances of each individual case which are relevant. It is to be stressed that a fundamental breach of contract must constitute also a non-fulfillment of a contractual obligation.

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