• Title/Summary/Keyword: representative

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Study on Efficient Time Domain Fatigue Analysis of Mooring Chain by Representative Mean Position (부유체 대표 평균 위치를 적용한 계류 라인의 시간 영역 피로 해석 효율화에 대한 연구)

  • Park, Jeongmoon;Kim, Yooil;Kim, Jeong-Hwan
    • Journal of Ocean Engineering and Technology
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    • v.32 no.5
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    • pp.333-340
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    • 2018
  • This paper addresses the concept of the representative mean position, which was devised to improve the numerical efficiency of a time domain fatigue analysis of a mooring chain. To investigate the influence of an artificial offset of the floater on the fatigue of the mooring chain, a parametric study was performed on the moored FPSO under various combinations of offsets and environmental conditions. Tension time histories were calculated using the de-coupled analysis method, and fatigue damages were calculated to determine the influence of the offset. The parametric study was extended to a more realistic case to determine the actual effect of the representative mean position, where a comparison was made between the two different analysis results, one using the representative mean position and the other one using the actual mean position. It was confirmed that the application of the representative mean position guaranteed the conservatism of the fatigue damage with the enhanced numerical efficiency in the time domain fatigue analysis.

Estimation of Representative Mechanical Property of Porous Electrode for Secondary Batteries with Homogenization Method (균질화 기법을 이용하여 기공이 있는 이차전지 극판의 대표 기계 물성 도출을 위한 연구)

  • Pyo, Changmin;Kim, Jaewoong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.9
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    • pp.85-91
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    • 2022
  • The demand for electric vehicles has increased because of environmental regulations. The lithium-ion battery, the most widely used type of battery in electric vehicles, is composed of a cathode, an anode, and an electrolyte. It is manufactured according to the pole plate, assembly, and formation processes. To improve battery performance and increase manufacturing efficiency, the manufacturing process must be optimized. To do so, simulation can be used to reduce wasted resources and time, and a finite-element method can be utilized. For high simulation quality, it is essential to reflect the material properties of the electrode by considering the pores. However, the material properties of electrodes are difficult to derive through measurement. In this study, the representative volume element method, which is a homogenization method, was applied to estimate the representative material properties of the electrode considering the pores. The representative volume element method assumes that the strain energy before and after the conversion into a representative volume is conserved. The method can be converted into one representative property, even when nonhomogeneous materials are mixed in a unit volume. In this study, the material properties of the electrode considering the pores were derived. The results should be helpful in optimizing the electrode manufacturing process and related element technologies.

Extraction and Indexing Representative Melodies Considering Musical Composition Forms for Content-based Music Information Retrievals (내용 기반 음악 정보 검색을 위한 음악 구성 형식을 고려한 대표 선율의 추출 및 색인)

  • Ku, Kyong-I;Lim, Sang-Hyuk;Lee, Jae-Heon;Kim, Yoo-Sung
    • The KIPS Transactions:PartD
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    • v.11D no.3
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    • pp.495-508
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    • 2004
  • Recently, in content-based music information retrieval systems, to enhance the response time of retrieving music data from large music database, some researches have adopted the indexing mechanism that extracts and indexes the representative melodies. The representative melody of music data must stand for the music itself and have strong possibility to use as users' input queries. However, since the previous researches have not considered the musical composition forms, they are not able to correctly catch the contrast, repetition and variation of motif in musical forms. In this paper, we use an index automatically constructed from representative melodies such like first melody, climax melodies and similarly repeated theme melodies. At first, we expand the clustering algorithm in order to extract similarly repeated theme melodies based on the musical composition forms. If the first melody and climax melodies are not included into the representative melodies of music by the clustering algorithm, we add them into representative melodies. We implemented a prototype system and did experiments on comparison the representative melody index with other melody indexes. Since, we are able to construct the representative melody index with the lower storage by 34% than whole melody index, the response time can be decreased. Also, since we include first melody and climax melody which have the strong possibility to use as users' input query into representative melodies, we are able to get the more correct results against the various users' input queries than theme melody index with the cost of storage overhead of 20%.

Representative of Sample and Efficiency of Estimation (표본의 대표성과 추정의 효율성)

  • Kim, Kyu-Seong
    • Survey Research
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    • v.6 no.1
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    • pp.39-62
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    • 2005
  • In this paper we investigate some concepts frequently called in sample surveys such as 'representative of sample' as well as 'consistency', 'unbiasedness', and 'efficiency' in estimation. The first is strongly related with sampling procedure including coverage rate of survey population, response rate in establishment survey, and recruit rate of final samples. The others, however, are concerned with both sampling design and corresponding estimators simultaneously. Whereas both consistency and unbiasedness are based on the representative sample, efficiency does not depend on the representative sample. The representative of sample can be increased by raising the rate of coverage, response and recruit as well. Consistency may be investigated according to variables of interest and auxiliary variables. The well-known raing-ratio weighting method is a method to increase consistency of auxiliary variables by means of matching population size in each cell. Efficiency is not directly related with the representative of sample, and allocation methods such as proportional and Neyman allocation in stratified sampling and post-stratification are all methods to increase the efficiency of estimation under the condition of satisfying the representative of sample.

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An Estimation Method of Representative Humanoids for Digital Human Simulation

  • Jung, Kihyo
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.3
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    • pp.237-243
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    • 2013
  • Objective: The present study developed an estimation method of boundary zone representative humanoids(hereafter, EBZ method) using descriptive statistics on the design target population. Background: The boundary zone method(hereafter, BZ method) generates representative humanoids at a boundary zone that statistically accommodates a designated percent of the design target population; however, the BZ method has a practical limitation because it requires a large scale anthropometric database on the design target population. Method: The EBZ method developed in the present study consisted of 3 steps. In the first step, the boundary zone of accommodating a designated percent(e.g., 90%) is formed under the assumption of normal distributions for anthropometric sizes. In the second step, cases that fall within the boundary zone are estimated using descriptive statistics(mean, standard deviation, and covariance) on the design target population. In the last step, K-mean cluster analysis is conducted for the cases, and representative humanoids are selected from each of clusters. Results: Evaluation results showed that mean accommodation percent of the EBZ method was 90.9%(range: 90.8~91.1%) which is similar to the target percent(90%). In addition, standard deviation of accommodation percent for 100 repetitions was 0.1%. Lastly, the number of representative humanoids generated by the EBZ method(n = 20) was similar to the BZ method(n = 16). Conclusion: The EBZ method can generate representative humanoids which accommodate a designated percent of the design target population using descriptive statistics. Application: The EBZ method can be utilized in the generation of humanoids for ergonomic design and evaluation of products when the large scale anthropometric database on the design target population is not existed.

A Study of 3D Virtual Fitting Model of Men's Lower Bodies in Forties by Morphing Technique. (모핑 기법을 활용한 40대 남성 하반신 가상모델 생성에 관한 연구)

  • Park, Sun-Mi;Nam, Yun-Ja;Choi, Kueng-Mi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.3 s.162
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    • pp.463-474
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    • 2007
  • With rapid expansion in e-retailing of apparel business, personalized fitting model service shows the possibility as the differentiated marketing strategy in cyber shopping. According as necessity of personalized fitting model construction rises, it is tried personalized fitting model creation in several fields such as computer engineering, mechanical engineering, information engineering. But, because existent study was concentrated only on human body modeling, it does not reflect average morphological characteristics of human body properly. In this study, we wish to examine if morphing is fit for expressing characteristic of average human body shape and suggest desirable morphing. We used 3-D scan data of 254 Korean middle aged men collected by Size Korea 2004. The result of this study are as follows: Lower body types were categorized by height hip girth and lower drop(hip girth-navel girth) which were main factors of lower body shape. Then each factor was divided into 3 groups respectively, 30% in the middle, over 30%, under 30%. In 27 groups, the group which belonged to 30% in the middle of height, 30% in the middle of hip girth, 30% in the middle of lower drop was selected as a representative group. We tested geometrical figure by differ volume, tilt, position of point. And we created a representative type of men's lower bodies by morphing the representative group and analyzed it's horizontal, vertical sections. A representative type which was created by morphing reflected a real body and changed realistically at the part of hip, crotch, calf muscle and so on. A cross sections of a representative type were similar to average cross sections of the representative group in size and shape. So it was proved that morphing was successful.

Considerations for BIBFRAME Acceptance of Expression and Representative Expression Attributes in LRM (BIBFRAME에서 LRM 표현형 및 대표표현형 속성 적용시 고려사항)

  • Lee, Mihwa
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.30 no.2
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    • pp.33-50
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    • 2019
  • Cataloging principles, cataloging rules, and encoding formats should considered LRM acceptance because LRM replaced FRBR as the conceptual model. This study identifies considerations for BIBFRAME acceptance of expression and representative expression attributes in LRM by using literature reviews and expert interviews. Primarily, work in BIBFRAME without expression as entity could map to work and expression of LRM and sustain expression by linking 2 works (work and expression). Second, BIBFRAME must consider association between representative expression attributes and specific expressions whose values can be transferred to the representative expression attributes. Third, representative expression attributes are different according to work types in LRM, and language, media, intended audience, and scale, that can be used as representative expression attributes in BIBFRAME, should be changed in class. Fourth, relation properties should be articulated for expanding networks between expressions originated from work in BIBFRAME. This study analyzes LRM and BIBFRAME by focusing on expression entity and representative expression attributes. More LRM study is needed on cataloging principles and cataloging rules.

A Study on Information Resources Recognition for Collection Development Policy of Gwangju Representative Library (광주대표도서관 장서개발정책 수립을 위한 정보자원 인식 연구)

  • Seongwoo Park
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.34 no.3
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    • pp.205-225
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    • 2023
  • The Study is to investigate information resources recognition of collection development policy that is a key element of Gwangju representative library. 68 Librarians, 98 library users and 20 libraries responded the questions of information resources. The fields of the questions are media, subjects and levels of information resources. The results of the research are as follows. First, the correlation coefficients between librarian group's preference and need is lower than that of the user group. Second, information resources for the knowledge-disadvantaged has low preference and need but the actual usage rate was high. Third, Librarians need to transfer historical paper and books, historical objects, technical reports and journal articles to the representative library. Fourth, information resources about philosophy have middle preference, low need and the resources have low need for transfer to representative library. Fifth, local historical resources and administrative policy resources has low usage rate high need for transfer to representative library. Sixth, the level of public library in Gwangju is 1.837 and the expectative level of Gwangju representative library is 3.325.

Diachronic Analysis of Korean Men's Wear Design based on Changes in Gender Roles (20세기 한국 남성 성역할에 따른 남성복 디자인 변화 특성 연구)

  • Lee, Jee-Hyun
    • Journal of the Korean Society of Costume
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    • v.60 no.8
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    • pp.51-66
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    • 2010
  • This study aimed to analyze the changing characteristics between Men's Gender Role and Men's wear Design in 20th century. To analyze the representative Men' Gender roles, the related studies and literatures reviewed. Literature reviews and quantitative studies were performed to analyze the changing differences of Korean Men's wear Deign as a symbolic factors of gender role. The results of study are as follows. 1) The representative men's gender roles in 1900's~1920's were 'Patriarchal/ Stern Man'. The narrow V-zone of jacket and shoulder, high shirt collars and well fitted suits expressed the stern images of that times. 2) In 1930's~50's, 'Enervated/ Escapist Man' were the representative images. They were expressed with wide lapels and shoulders, emphasized V-zone and abundant trousers. Especially 40's style was under the influence of American 'Zoot Style'. 3) The representative gender roles were the men of 'Producer/Provider' in 60's~70's. Shortened jacket, wide lapels & neckties, slim trousers were used to express the strong & young images of Producer/ Provider during the industrialization era. 4) The representative gender roles were 'Attentive/ Intellectual/ Beautiful Men' in 80's~90's. The exaggerated round shoulders which were influenced by 'Big Look', and easy silhouette were related with the attentive images.

Decision of the Representative Moving Direction of a Storm Event (호우사상의 대표 이동방향 결정)

  • Yoo, Chul-Sang;Park, Chang-Yeol
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.2
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    • pp.91-102
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    • 2010
  • This study analyzed methodologies for determining the representative direction of a storm event. The mean direction, median direction, and modal direction of von Mises distribution were considered as representative directions. In addition, the results with and without considering the storm moving distance were also compared. As results, the modal directions of von Mises distribution were found to explain the directional characteristics of a moving storm much better than other methods. Also, it was found that the storm moving distance has a significant effect on the determination of representative directions of a moving storm, whose uncertainty can also be decreased significantly by considering the moving distance.