• Title/Summary/Keyword: Density independence

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The Study of Functional Independence and Bone Mineral Density in Athletes With Spinal Cord Injury (척수 손상을 가진 운동선수와 비운동선수의 일상생활 기능과 골밀도 비교연구)

  • Shin, Hwa-Kyung;Kim, Youn-Joung
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.1
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    • pp.119-124
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    • 2012
  • 목적 : 본 연구는 척수손상환자들 중 신체활동 정도가 급격하게 차이 나는 운동 선수군과 비선수군의 일상생활동작과 골밀도를 비교 분석하는데 그 목적이 있다. 방법 : 본 연구를 위해 20명(선수 10명, 비선수 10명)의 SCI 환자가 실험에 참가하였다. 골밀도 측정을 위해 이중에너지 방사선골밀도 측정기(Lunar Prodigy, GE Healthcare. England)를 이용하여 종골부위(calcaneus)의 골밀도를 측정하였다. 척수손상환자의 일상 생활 기능을 측정하기 위해 자조관리(self care), 호흡과 괄약근 조절 (respiration and sphincter management task), 이동(transfer)의 세 영역으로 나누어진 SCIM II(Spinal Cord Injury Measurement II)을 이용하였다. 척수손상환자들 중 운동 선수군과 비운동 선수군의 일상생활 동작과 골밀도를 비교 하기 위해 SPSS 14.0 통계 프로그램의 independent t-test를 이용하여 통계분석을 실시하였고 일상생활 동작과 골밀도의 상관관계는 Pearson correlation을 실시하였다. 유의수준은 ${\alpha}$=.05로 통계처리 하였다. 결과 : 검사 결과 선수군이 비선수군보다 통계적으로 유의하게 큰 SCIM 점수와 T-score를 보여주었다. 결론 : 일상생활동작을 측정하기 위하여 SCIM II(SpinalCordIndependenceMeasureII) 척도를 사용하였는데 선수군이 비선수군에 비해 유의하게 높은 SCIM II 총점을 나타내어 운동을 통한 훈련이 척수손상환자의 기능적 활동을 향상시킬 수 있다고 사료된다. 그리고 골밀도 측정 결과 선수군이 비선수군에 비해 통계적으로 유의하게 높은 골밀도를 나타내었다. 이 역시 강도 높은 훈련이 척수손상환자에게 나타날 수 있는 신체구성을 강화시켜줄 수 있을 것으로 사료된다. 운동을 통한 재활 중에서 그 강도가 높을수록 신체의 구성적, 기능적 측면 뿐 아니라 신경의 가소성 측면에서도 증가를 기대해 볼 수 있을 것으로 판단된다.

A New Information Index of Axiomatic Design for Robustness (강건성을 고려한 공리적 설계의 새로운 정보 지수)

  • Hwang, Kwang-Hyeon;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2073-2081
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    • 2002
  • In product design and manufacturing, axiomatic design provides a systematic approach for the decision-making process. Two axioms have been defined such as the Independence Axiom and the Information Axiom. The Information Axiom states that the best design among those that satisfy the independence axiom is the one with the least information content. In other words, the best design is the one that has the highest probability of success. On the other hand, the Taguchi robust design is used in the two-step process; one is "reduce variability," and the other is "adjust the mean on the target." The two-step can be interpreted as a problem that has two FRs (functional requirements). Therefore, the Taguchi method should be used based on the satisfaction of the Independence Axiom. Common aspects exist between the Taguchi method and Axiomatic Design in that a robust design is induced. However, different characteristics are found as well. The Taguchi method does not have the design range, and the probability of success may not be enough to express robustness. Our purpose is to find the one that has the highest probability of success and the smallest variation. A new index is proposed to satisfy these conditions. The index is defined by multiplication of the robustness weight function and the probability density function. The robustness weight function has the maximum at the target value and zero at the boundary of the design range. The validity of the index is proved through various examples.gh various examples.

Forest Canopy Density Estimation Using Airborne Hyperspectral Data

  • Kwon, Tae-Hyub;Lee, Woo-Kyun;Kwak, Doo-Ahn;Park, Tae-Jin;Lee, Jong-Yoel;Hong, Suk-Young;Guishan, Cui;Kim, So-Ra
    • Korean Journal of Remote Sensing
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    • v.28 no.3
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    • pp.297-305
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    • 2012
  • This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

Theoretical Consideration of Nondestructive Testing by use of Vertical Magnetization and Magneto-Optical Sensor

  • Lee, Jinyi;Tetsuo Shoji;Dowon Seo
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.640-648
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    • 2004
  • This paper describes a new magnetization method for non-destructive testing with magneto-optical sensor (denoted as MO sensor) which have the following characteristic : high observation sensitivity, independence of the crack orientation, and precise imaging of a complex crack geometry such as multiple cracks. When a magnetic field is applied normally to the surface of a specimen which is significantly larger than its defects, approximately the same magnetic charge per unit area occurs on the surface of the specimen. If there is a crack in the specimen, magnetic charge per unit area has the same value at the bottom of the crack. The distribution of the vertical component of the magnetic flux density, B$\_$Z/, is almost uniform over the no-crack area (denoted as B$\_$Z,BASE/), while the magnetic flux density is smaller in the surroundings of the crack(denoted as B$\_$Z,CRACK/) If B$\_$Z, BASE/ is a bit larger than the saturated magnetic flux density of the MO sensor (B$\_$s/) , then small magnetic domains occur over the crack area and a large domain over the non-crack area because B$\_$Z,CRACK/ is smaller than B$\_$s/.

An Improved Clustering Method with Cluster Density Independence (클러스터 밀도에 무관한 향상된 클러스터링 기법)

  • Yoo, Byeong-Hyeon;Kim, Wan-Woo;Heo, Gyeongyong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.248-249
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    • 2015
  • Clustering is one of the most important unsupervised learning methods that clusters data into homogeneous groups. However, cluster centers tend leaning to high density clusters because clustering is based on the distances between data points and cluster centers. In this paper, a modified clustering method forcing cluster centers to be apart by introducing a center-scattering term in the Fuzzy C-Means objective function is introduced. The proposed method converges more to real centers with small number of iterations compared to the original one. All the strengths can be verified with experimental results.

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A Typology of Modern Housing in Malaysia

  • Ju, Seo-Ryeung;Omar, Saari Bin
    • International Journal of Human Ecology
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    • v.11 no.1
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    • pp.109-119
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    • 2010
  • Modernization of cities and housing in Malaysia is a reflection of the history of the establishment of colonial trading ports for worldwide maritime trade and exchange. In cosmopolitan cities, new housing typology appeared from the influence of various ethnic immigrants and with the fusion of traditional Malay housing characteristics. This study is to focus on classifying the housing typologies of Malaysia which were formed through the modernization process of cities. The typologies of modern housing in Malaysia can be classified into two categories. The first category is the 'transformation of traditional housing'. The representative typology of this group is the ubiquitous shophouse. The shophouse was originally brought in by the Chinese immigrants from the south coast of China and transformed into the Malaysian urbanscape. The other typology is a detached-house known as the bungalo, which was the housing style combining the Malay traditional timber house and European palazzo. The second category is the 'modern urban housing typology'. Modern urbanization after the independence from the British in 1957 required the maximum utilization of land. To accommodate new social and economic needs, the new typologies were developed in the form of medium-density terrace houses (row houses) and high-density apartment. In the suburban areas, the British terrace house was adopted and developed into unique Malaysian terrace house and semi-detached house based on the British system of land sub division. In premium area of the city, luxurious housing type in the form of high-end condominium is one of the popular housing for upper middle-class and high-class society.

Cities in the Sky: Elevating Singapore's Urban Spaces

  • Samant, Swinal
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.137-154
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    • 2019
  • Singapore has seen a phenomenal and an unprecedented transformation from a swampland to a high density urban environment since its independence in 1965, made possible largely and single-handedly by the sustained efforts of its government. Indeed, urban space is a key vehicle for achieving urban social, environmental, economic, and cultural sustainability. The dense urban context in Singapore has seen an emergence and increase in elevated spaces in the form of sky-gardens, sky-bridges and sky-courts in a range of building types, seemingly seeking to tie together the different horizontal and vertical components of the city. This paper, therefore, examines the effectiveness of elevated urban spaces and pedestrian networks in Singapore and their ability to contribute to the horizontal to vertical transitions, and consequently to the urban vitality and accessibility. It does this through the analysis of two key developments: Marina Bay Sands and the Jurong Gateway. In particular, it considers the implications of certain constraints placed on urban spaces by their inherent location at height, in addition to the familiar privatization of public spaces, over-management of spaces, and their somewhat utilitarian characteristics. The paper argues that some of these issues may pose detrimental effects on the publicness of these spaces that in turn may lead to such spaces being underused and therefore adding redundancies and further stress to Singapore's urban land. Finally, the paper outlines key strategies that may help overcome the aforementioned issues, including the disjuncture associated with elevated spaces such that they may become a seamless extension of the urban spaces on ground.

CHARACTERIZATIONS OF THE GAMMA DISTRIBUTION BY INDEPENDENCE PROPERTY OF RANDOM VARIABLES

  • Jin, Hyun-Woo;Lee, Min-Young
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.2
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    • pp.157-163
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    • 2014
  • Let {$X_i$, $1{\leq}i{\leq}n$} be a sequence of i.i.d. sequence of positive random variables with common absolutely continuous cumulative distribution function F(x) and probability density function f(x) and $E(X^2)$ < ${\infty}$. The random variables X + Y and $\frac{(X-Y)^2}{(X+Y)^2}$ are independent if and only if X and Y have gamma distributions. In addition, the random variables $S_n$ and $\frac{\sum_{i=1}^{m}(X_i)^2}{(S_n)^2}$ with $S_n=\sum_{i=1}^{n}X_i$ are independent for $1{\leq}m$ < n if and only if $X_i$ has gamma distribution for $i=1,{\cdots},n$.

An advanced single-particle model for C3S hydration - validating the statistical independence of model parameters

  • Biernacki, Joseph J.;Gottapu, Manohar
    • Computers and Concrete
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    • v.15 no.6
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    • pp.989-999
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    • 2015
  • An advanced continuum-based multi-physical single particle model was recently introduce for the hydration of tricalcium silicate ($C_3S$). In this model, the dissolution and the precipitation events are modeled as two different yet simultaneous chemical reactions. Product precipitation involves a nucleation and growth mechanism wherein nucleation is assumed to happen only at the surface of the unreacted core and product growth is characterized via a two-step densification mechanism having rapid growth of a low density initial product followed by slow densification. Although this modeling strategy has been shown to nicely mimic all stages of $C_3S$ hydration - dissolution, dormancy (induction), the onset of rapid hydration, the transition to slow hydration and prolonged reaction - the major criticism is that many adjustable parameters are required. If formulated correctly, however, the model parameters are shown here to be statistically independent and significant.

Distributed estimation over complex adaptive networks with noisy links

  • Farhid, Morteza;Sedaaghi, Mohammad H.;Shamsi, Mousa
    • Smart Structures and Systems
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    • v.19 no.4
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    • pp.383-391
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    • 2017
  • In this paper, we investigate the impacts of network topology on the performance of a distributed estimation algorithm, namely combine-then-adaptive (CTA) diffusion LMS, based on the data with or without the assumptions of temporal and spatial independence with noisy links. The study covers different network models, including the regular, small-world, random and scale-free whose the performance is analyzed according to the mean stability, mean-square errors, communication cost (link density) and robustness. Simulation results show that the noisy links do not cause divergence in the networks. Also, among the networks, the scale free network (heterogeneous) has the best performance in the steady state of the mean square deviation (MSD) while the regular is the worst case. The robustness of the networks against the issues like node failure and noisier node conditions is discussed as well as providing some guidelines on the design of a network in real condition such that the qualities of estimations are optimized.