• Title/Summary/Keyword: movement distribution

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A Study on the Machined Surface Morphology of Laminate Composite (적층구조 복합재료의 절삭면 형상에 관한 연구)

  • Wang, Duck Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.12
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    • pp.130-138
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    • 1995
  • Machined graphite/epoxy surfaces were studied by using SEM (Scanning Electron Microscopy), surface profilometry and its analysis to determine suitable surface describing parameters for machined unidirectional and multidirectional laminate composite. The surface roughness and profile are found to be highly depdndent on the fiber layup direction and the measurement direction. It was possible to machine 90 .deg. and -45 .deg. plies due to the adjacent plies, which were holding those plies. It was found that the microgeometrical variations in terms of roughness parameters $R_{a}$ without $D_{y}$(Maximum Damage Depth) region and $D_{y}$are better descriptors of the machined laminate composite surface than commonly used roughness parameters $R_{a}$and $R_{max}$ The characteristics of surface profiles in laminate composite are well represented in CPD (Cumulative Probability Distribution) plot and PPD (Percentage Probability Density) plot. Edge-trimmed multidirectional laminate surfaces are Gaussian and random for profiles measured along the tool movement direction, they are periodic and non-Gaussian in the direction perpendicular to the tool movement.t.ent.t.

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A study on the topology optimization of structures (구조물의 토폴로지 최적화에 관한 연구)

  • Park, Sang-Hun;Yun, Seong-Gi
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.8
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    • pp.1241-1249
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    • 1997
  • The problem of structural topology optimization can be relaxed and converted into the optimal density distribution problem. The optimal density distribution must be post-processed to get the real shape of the structure. The extracted shape can then be used for the next process, which is usually shape optmization based on the boundary movement method. In the practical point of view, it is very important to get the optimal density distribution from which the corresponding shape can easily be extracted. Among many other factors, the presence of checker-board patterns is a powerful barrier for the shape extraction job. The nature of checker-board patterns seems to be a numerical locking. In this paper, an efficient algorithm is presented to suppress the checker-board patterns. At each iteration, density is re-distributed after it is updated according to the optimization rule. The algorithm also results in the optimal density distribution whose corresponding shape has smooth boundary. Some examples are presented to show the performance of the density re-distribution algorithm. Checker-board patterns are successfully suppressed and the resulting shapes are considered very satisfactory.

The Theory for Predicting the Moisture Distribution of Stored Grains

  • Murata, Satoshi;Kawao, Toshio;Nakano, Kohei;Kida, Tamaki
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.932-941
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    • 1993
  • High moisture content of barley seeds, which were carried to the laboratory within 10 minutes after harvest, were stored in air tight bottle at constant temperature, and the individual moisture contents the grains were measured at predecided tim intervals. The theory of predicting the moisture movement between two kinds of different moisture content grains was tried to apply to the prediction of the moisture distribution and tried to apply to the prediction of the moisture distribution and the comparison of the predicted values with the observed dta showed the good suitability of the theory. The shape of the moisture distribution predicted form the theory were similar to the observed ones for the temperature range of 10 to $50^{\circ}C$. This study will be useful in designing the mix-storage facility or dryer.

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US Purchasing Managers' Index and its Impact on Korea and US

  • Jeon, Ji-Hong
    • Journal of Distribution Science
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    • v.15 no.3
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    • pp.17-25
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    • 2017
  • Purpose - The study is to examine the impact of the US Purchasing Managers' Index (PMI) on Korea and the US industrial economy including the distribution industry. We analyze its effect on the industrial economy centered on the distribution industry using economy indices in Korea and the US. Research design, data, and methodology - The variables are used to analyze the dynamic relationship which occurs among the US PMI, the industrial production index, producer price index, unemployment rate, and manufacturing Inventories Index in Korea and the US from January 1990 to July 2016 using Vector Error Correction Model. Results - As a main result, the impact of the US PMI on all the economy indices both Korea and the US has the same cyclical movement. The US PMI is positively related to the producer price and the industrial production index of Korea and the US, while it is negatively related to unemployment rate, and the manufacturing inventories index in Korea and the US. Conclusions - The US PMI as an advanced index has a power to predict the economies on Korea and the US. In the end, we find that the US PMI has a great impact on Korea and the US industrial economy.

Relationship between halophyte distribution and soil environmental factors in the west coast of South Korea

  • Lee, Seung Ho;Lee, Jeom-Sook;Kim, Jong-Wook
    • Journal of Ecology and Environment
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    • v.42 no.1
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    • pp.12-19
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    • 2018
  • Background: The objective of this study was to determine the relationship between soil environmental factors and halophyte distribution in the west coast of South Korea. Soils of our study sites were categorized into two groups: salt marsh and estuary marsh. Results: Salinity was higher in the salt marsh group than that in the estuary marsh group. However, total nitrogen, silt, and clay contents were higher in the estuary marsh group than those in the salt marsh group. Although altitude had a wider range in the salt marsh group, the mean altitude was higher in the estuary marsh group than that in the salt marsh group. Annual halophytes of seed propagation species were distributed parallel to the coast line on salt marsh. Higher coverage of vegetation was found in the area closer to the coast line. Plant density was higher near dead parental plants in estuary marsh, showing less difference in area that was more distant from the coast line. Conclusions: Results of canonical correspondence analysis (CCA) for vegetation distribution and sediment environmental factors and germination analysis in the coast line showed significant relationship with halophyte distribution. Therefore, they can be used as an indicator of coastal plant movement due to sea level rise.

The Analysis on Relation between Hamstring Length and Static Uprighting Balance (넙다리 뒤근육의 길이와 정적 기립균형과의 상관성 분석)

  • Nam, Kun-Woo
    • Journal of Korean Physical Therapy Science
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    • v.18 no.1
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    • pp.51-60
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    • 2011
  • Purpose: The purpose of this study was to investigate hamstring length during static uprighting position using weight distribution ratio. Methods: Ninety-six volunteers(56 males) were participated. The active knee extension test(AKE) was measured 3 times on both legs. The mean score of AKE was obtained. Then, the measurement of weight distribution ratio was observed 3 times on both legs, and its mean value was also calculated. Subjects were divided four groups based on their hamstring length measurement; both hamstring shortening group, left hamstring shortening group, right hamstring shortening group and normal hamstring length group. One-way ANOVA was employed to analyse collected data. Pearson's correlation was also hired to see any relationship between the hamstring length and the weight distribution. Results: In anterior/left area and posterior/right area, both hamstring shortening group left hamstring shortening group were superior to right hamstring shortening group and normal hamstring length group. Significant difference was existed statistically(p<.05) between groups. The correlation analysis between hamstring length and weight distribution ratio has not been shown any significant findings(Pant/post=0.733, Plt/rt=0.135). Conclusion: The results of the study may be applied to therapeutic management in posture and movement skill in musculoskeletal physical therapy.

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A Study on Career Movement and Career Development of Librarians Workforce (사서인력의 경력이동 및 경력개발에 관한 연구)

  • Noh, Young-Hee;Ahn, In-Ja
    • Journal of the Korean Society for information Management
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    • v.26 no.4
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    • pp.147-168
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    • 2009
  • Professions with librarianship can be found in various fields. It includes all different kinds of libraries, including academic, public, special, and school libraries. Moreover, there are national and commercial information distribution bodies, and other bodies supporting the national body such as library automation companies, library supply companies, and library outsourcing companies. Careers of those who have studied in library and information science could be developed in all these fields. High flexibility and labour turnover can be expected due to the wide range of career fields. Nevertheless, there have been very little studies reflecting the reasons of high level of turnovers and flexibility in librarian workforce. Therefore, this paper invastigates career movement and development of librarian as a foundation stone of further researches. It also analyzes career development process of librarians, including career paths of those working in libraries and other related areas, their efforts for career development, factors influencing their career movements.

Effect of Horizontal Eye Movements on the Heart Rate Variability after Exposure to a Fear-Inducing Film Clip (공포 영화 장면 노출 후 수평적 안구 운동이 심박수 변이도에 미치는 영향)

  • Lee, Haewon;Yum, Myung-Kul;Kim, Seok Hyeon;Lee, Yun Jeong;Kim, Daeho
    • Korean Journal of Biological Psychiatry
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    • v.15 no.1
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    • pp.35-45
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    • 2008
  • Objectives : There has been a continued debate regarding the role of eye movements in Eye Movement Desensitization and Reprocessing(EMDR). This study examined the possible autonomic effect of horizontal eye movements after being exposed to fearful stimuli. Methods : Fifty two healthy adult women were randomly allocated to eye movement or eye fixed groups after watching a five minute fear-inducing film clip. ECG was recorded during the resting state, after watching the clip, and the treatment. A spectral power analysis of the heart rate variability was performed. As the variables violated the rule of normal distribution and the number in each group is small the non-parametric test was used. Results : Overall, we did not find the differences between the groups in both time and frequency domains. Some minor differences found were not consistent with results from previous studies. Conclusions : Effect of eye movement on autonomic nervous system during fear desensitization was not supported in this experiment. Further study with other psychophysiological measures is needed to understand the role of eye movements in treatment of traumatic memory.

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A Study on the Analysis of the Directional Information Sign to Destinations and Spatial Configuration in the Exhibition Spaces of Museum (박물관 전시부문의 관람객 유도사인과 공간구조)

  • Lim, Che-Zinn;Park, Moo-Ho
    • Korean Institute of Interior Design Journal
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    • v.15 no.6 s.59
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    • pp.205-212
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    • 2006
  • The premise of this study is that an ultimate objective in planning an exhibition space is spectators' experiences shaped by a result of their first-hand experiences and responses within an exhibition space, and this result can be recognized in the spectators' movement. Thus, the sign system that can directly affects viewers' main line of flow and movement patterns was examined vis--vis a mutually complementary relation in a triangular composition with the structure of exhibition space and the exhibition contents. Based on the findings, predictive values before and after a complementary application of the sign system to the structure of exhibition space was analyzed and its validity was assessed. The results of this research analysis were drawn as follows. It was shown that an understanding of the locations of direction signs and the degree of recognition can function as an important factor to predict viewers' movement, along with an understanding of topological characteristics of an exhibition space. In terms of the connection and disconnection of space units that form the space structure, it suggests that the distribution of signs and the degree of recognition can adjust the degree of connection and disconnection. Even though exhibition spaces for research subjects were selected from a relatively large number of museums, but the research was limited with a focus on the structure of exhibition space and sign systems. Thus, it is proposed that future studies should be conducted by including varieties of exhibition and environmental factors.

THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF MANDIBULAR STRESSES UNDER COMPLETE DENTURES WITH VARIANT ARTIFICIAL TEETH FORMS AND OCCLUSAL PATTERNS (총의치 교합면 형태가 하악골 응력 분포에 미치는 영향에 관한 삼차원 유한요소분석적 연구)

  • Lee Cheol-Gyu;Kim Chang-Whe;Kim Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.3
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    • pp.351-384
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    • 1993
  • Complete denture occlusion must be developed to function efficiently and with the least amount of trauma to the supporting tissues. For the preservation of supporting tissues, it is imperative to reduce to a minimum the functional stress induced by dentures. The magnitude of the horizontal component of functional stress contributed by various occlusal teeth forms has not been studied. This study was aimed to investigate the influence of different occlusal teeth forms on the mode of distribution of the stresses in the mandibular tissue, and the displacement of lower dentures during the variant functional movement of mandible for this study three dimensional finite element analysis was used. FEM models were created using commercial software Super Sap for IBM 32 bit computer. The model was composed of 3380 brick elements and 4346 nodes. The results were as follows. 1. The magnitude of stress was similar between two models in centric occlusion, in the case of anatomic model, the stress was concentrated on the buccal side of alveolar ridge beneath the bicuspids. 2. During the protrusive movement, the increasing of stress from the posterior to anterior part of mandible was seen in the case of anatomic model. 3. During the lateral movement, the stress of anatomic model was greater than that of nonanatomic model. 4. The stress of anatomic model was concentrated on the anterior region of residual ridge during the lateral movement. 5. In the case of anatomic model the anterior part of denture was displaced severely at the centric and lateral position, but the denture of nonanatomic model was displaced minutely at the protrusive and lateral position.

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