• 제목/요약/키워드: A-D relation

검색결과 1,648건 처리시간 0.035초

FEM을 이용한 Belt Width와 Separation에 관한 연구 (A Study on the Belt width and Separation of Tire using FEM)

  • 김성래;성기득;김선주;조춘택
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 춘계학술대회 논문집
    • /
    • pp.2006-2010
    • /
    • 2005
  • This study is concerned with the relation between steelbelt and belt edge separation. Belt edge separation causes tire burst and threatens passenger's safety. For that reason, it is important to predict durability caused by belt edge separation first in tire structure design step. In this study, to predict belt edge separation, we suggest the prediction method of belt edge separation and evaluate the effect of steelbelt width on the belt edge separation using FEM. We study on analysis parameter also to do exact estimation about the shear behaviour of belt edge area.

  • PDF

한국형 고속전철용 판토그라프의 거동 특성과 열차속도와의 상관관계와 경향 (Relation and Variation Trend between the Behavior of the Pantograph vs. the Vehicle Running Speed in Korean High Speed Train)

  • 목진용;박춘수;조용현;최강윤;김기환
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2003년도 추계학술대회논문집
    • /
    • pp.170-176
    • /
    • 2003
  • The pantograph for Korean High Speed Train was developed and had been evaluating by through "G7- R&D for home grown high speed train technology". In this study, a relation in mechanical aspect between the train running speed and the current collecting performance of the pantograph is conducted.'for this study, a measuring system for current collecting performance and mechanical characteristics is developed and installed on the prototype Korean High Speed Train, and measurement is conducted while the train runs on the test track. The measuring system is composed of video monitoring system and telemetry & data processing unit. It monitors whether the hazard behavior in the pantograph is occurs or not, and measures acceleration and vertical contact force between the pan head and catenary. Through this study, evaluation of a mechanical vibration characteristics and trend of the pantograph and a interface performance of pantograph - catenary up to 200㎞/h train speed are facilitated.

  • PDF

수리철학의 사상과 과제에 관한 연구 (A Study on the Thoughts and Problems of Philosophy of Mathematics)

  • 이건창
    • 한국수학사학회지
    • /
    • 제18권1호
    • /
    • pp.67-74
    • /
    • 2005
  • 본 연구에서는 수리철학의 사상과 과제를 분석하기 위하여 수리철학과 형이상학의 내용의 조화적인 유형의 분석을 중심으로 살펴보기로 한다. 형이상학과 수리철학의 논쟁적인 의문은 특히 수학적 추상의 본질과 관련하여 수리철학적 입장에서만 가능함을 알 수 있다. 따라서 이러한 태도는 미래의 철학에 대한 수학의 관계에 있어서 명백한 영향력을 가지게 될 수 있고 많은 연구가 미래에 큰 의미를 부여할 수 있기를 기대한다.

  • PDF

R&D Perspective Social Issue Packaging using Text Analysis

  • Wong, William Xiu Shun;Kim, Namgyu
    • 한국IT서비스학회지
    • /
    • 제15권3호
    • /
    • pp.71-95
    • /
    • 2016
  • In recent years, text mining has been used to extract meaningful insights from the large volume of unstructured text data sets of various domains. As one of the most representative text mining applications, topic modeling has been widely used to extract main topics in the form of a set of keywords extracted from a large collection of documents. In general, topic modeling is performed according to the weighted frequency of words in a document corpus. However, general topic modeling cannot discover the relation between documents if the documents share only a few terms, although the documents are in fact strongly related from a particular perspective. For instance, a document about "sexual offense" and another document about "silver industry for aged persons" might not be classified into the same topic because they may not share many key terms. However, these two documents can be strongly related from the R&D perspective because some technologies, such as "RF Tag," "CCTV," and "Heart Rate Sensor," are core components of both "sexual offense" and "silver industry." Thus, in this study, we attempted to discover the differences between the results of general topic modeling and R&D perspective topic modeling. Furthermore, we package social issues from the R&D perspective and present a prototype system, which provides a package of news articles for each R&D issue. Finally, we analyze the quality of R&D perspective topic modeling and provide the results of inter- and intra-topic analysis.

3D Laser Scanning을 이용한 댐체의 안정성 검토 (A Examination on Stability of Dam using 3D Laser Scanning System)

  • 이재원;손호웅;윤부열
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2007년도 춘계학술발표회 논문집
    • /
    • pp.451-454
    • /
    • 2007
  • There is an inseparable relation between human race and engineering work. As world developed into highly industrialized society, a diversity of large structures is being built up correspondently to limited topographical circumstance. Though large structures are national establishments which provide us with convenience of life, there are some disastrous possibilities which were never predicted such as ground subsidence and degradation. It is very difficult to analyze the volume of total metamorphosis with the relative displacement measurement system which is now used and it is impossible to know whether there is structural metamorphosis within a permissible range of design or not. In this research with an object of 13-year-old earthen dam, through generating point-cloud which has 3D spatial coordinates(x, y, z) of this dam by means of 3D Laser Scanning, we can get real configuration data of slanting surface of this dam with this method of getting a number of 3D spatial coordinates(x, y, z). It gives 3D spatial model to us and we can get various information of this dam such as the distance of slanting surface of dam, dimensions and cubic volume. It can be made full use of as important source material of reinforcement and maintenance works to detect previously the bulging of the dam through this research.

  • PDF

Will a U.S. Earned Ph.D. Help a Teacher Educator Apply Theory to Practice in Korea?: A Case Study

  • Lee, Yoo-Jean
    • 영어어문교육
    • /
    • 제15권3호
    • /
    • pp.199-222
    • /
    • 2009
  • As great attention is given to a high quality of English education in Korea, more and more in-service and pre-service English teachers are looking for an opportunity to study in an English speaking country to become better qualified teachers. However, after receiving a degree in an English speaking country, many teachers fail to apply what they have learned to their own teaching due to their tensions of identity, beliefs, knowledge, and professionalism within the changes of sociocultural settings. By using sociocultural theory as a theoretical framework, this paper explores how formal training and Ph.D. studies in the U.S. have influenced a Korean teacher educator in applying theory to practice in relation to her identity, beliefs, knowledge, and professionalism during 30 years of her teaching experience. Rather than facing tensions, the teacher educator has been willing to change her roles, broaden and deepen her beliefs in teaching and knowledge about theory of teaching and learning, and continue her professional development. Limitations and implications of the study are provided.

  • PDF

3D 영상 시청 시 콘텐츠에 따른 깊이 인지 변화와 회복도 분석 (An Analysis of Recovery Rate and a Change of Depth Recognition After Watching 3D Videos)

  • 김용우;강행봉
    • 한국멀티미디어학회논문지
    • /
    • 제18권1호
    • /
    • pp.88-96
    • /
    • 2015
  • The recent increase in the production of 3D contents allowed viewers to experience various 3D contents. However, some of the viewers did not experience 3D depth well. Several researches were done in past to measure viewers' 3D depth perception, but these researches were done with certain limitations. In this paper, we measured viewers' 3D depth perception and recovery rate in relation with the changes in binocular disparities, saturation, and brightness values after subjects' watching 2D/3D contents. The results showed that when viewers watched the 3D content with positive binocular disparities for 42 minutes, viewers felt that the object seemed to have moved further forward than it was before; with 3D content with negative binocular disparities, viewers felt that the object seemed to be moved backwards. We found that the locational differences of the object in positive disparities were greater than those in the negative binocular disparities. The recovery rate was computed by comparing two measured values of before and after watching 3D contents for 30 minutes. On average, after 30-minute break, viewers showed roughly 50 % of recovery rate.

정신분열병 환자에서 Cytochrome P450 2D6 유형에 따른 부작용에 대한 연구 (Antipsychotics Induced Etrapyramidal Symptoms in Schizophrenics in Relation to Cytochrome P450 2D6 Genotype)

  • 이민수;남종원
    • 생물정신의학
    • /
    • 제6권2호
    • /
    • pp.189-192
    • /
    • 1999
  • The genetically determined CYP2D6 activity may be considered to be associated with antipsychotic induced extrapyramidal side effects with interindividual variation. Genetic polymorphism of CYP2D6 was determined by polymerase chain reaction(PCR) and MspI restriction fragment length polymorphisms(RFLP) for 194 schizophrenics. Subjects with a 334bp band were classified a1a1, those with 229bp and 105bp bands a2a2, and those with all three bands a1-a2. We did not identify schizophrenic subject with poor metabolizer. 194 schizophrenic patients previously treated neuroleptic medication, were assessed by Extrapyramidal Symptom Rating Scale(ESRS).The cases were composed of 33 akathisia, 47 parkinsonism, 21 tardive dyskinesia. These results are similar to the previous understanding that the poor metabolizer is very rare in Orientals compared to Caucasians, therefore, it considered that CYP2D6 genotypes have maybe no association with schizophrenia and extrapyramidal side effects in Koreans.

  • PDF

Salt-dilution 방법을 이용한 산지소하천의 유량과 유속 관계 분석 (Hydraulic Relation of Discharge and Velocity in Small, Steep Mountain Streams Using the Salt-dilution Method)

  • 양현제;이성재;임상준
    • 한국산림과학회지
    • /
    • 제107권2호
    • /
    • pp.158-165
    • /
    • 2018
  • 산지하천의 평균유속을 정확하게 추정하는 것은 하천의 수리적 흐름을 이해하고, 사방댐과 같은 사방구조물 최적 설계를 위해 중요하다. 산지하천의 평균 유속에 대한 연구는 부족한 실정이나 최근에는 상대적으로 자료 확보가 용이한 유량 자료를 이용하여 유량과 평균유속의 관계를 파악하는 연구들이 많이 진행되고 있다. 이 연구에서는 8개소의 서로 다른 산지소하천에서 조사된 87회의 유량과 평균 유속 자료를 분석하였다. 산지하천의 유량과 평균유속을 측정하기 위해 salt-dilution 방법을 사용하였으며, 평균유속은 도달 시간의 조화 평균을 적용하여 구하였다. 하천의 거칠기 높이를 이용하여 유량과 유속과의 무차원 관계식을 도출하였다. 거칠기 높이는 하상재료의 $D_{50}$, $D_{84}$와 하상변위의 ${\sigma}_{pro}$, $IPR_{90}$를 이용하였으며, ${\sigma}_{pro}$$IPR_{90}$의 정확성이 더 높게 나타났다. 일반적으로 유량과 평균 유속은 지수함수 관계를 보였다.

자기주도학습준비도와 수학적성향 사이의 관계 연구 - D대학교 공과대학 신입생을 중심으로 - (A Study on the relation between SDLR and Mathematical Inclination - A Case Study on Engineering Freshmen in D University -)

  • 이정례;이경희
    • 한국수학교육학회지시리즈E:수학교육논문집
    • /
    • 제26권1호
    • /
    • pp.15-28
    • /
    • 2012
  • 본 연구에서는 중위권 공과대학 신입생들의 자기주도학습준비도와 수학적성향 사이의 관계를 알아보기 위하여, D대학교 공과대학 2011학년도 신입생들을 대상으로 자기주도학습준비도 검사와 수학적성향 검사 및 수학에 대한 인식 설문을 실시하였고, 자기주도학습준비도를 수학적성향의 요인 및 수학에 대한 인식 정도에 따라 분석하였다. 연구 결과, D대학교 공과대학 2011학년도 신입생들은 대체로 자기주도학습준비도가 미약하며, 자기주도학습준비도는 수학적성향 및 수학에 대한 인식과 밀접한 관계가 있는 것으로 나타났다. 본 연구 결과를 바탕으로 효율적인 대학수학 교육을 위해서는 대학수학 교수 학습에서 자기주도학습준비도의 향상에 초점을 두어야 함을 제언하였다.