• 제목/요약/키워드: complexity science

검색결과 1,870건 처리시간 0.039초

보행 시 낙상 유무에 따른 압력중심점의 복잡성 비교 (Complexity Comparison of Center of Pressure between Fallers and Non-fallers during Gait)

  • Park, Sang Kyoon;Ryu, Sihyun;Kim, Jongbin;Yoon, Sukhoon;Ryu, Jiseon
    • 한국운동역학회지
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    • 제29권2호
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    • pp.113-119
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    • 2019
  • Objective: The purpose of this study was to investigate the effect of the falls on the center of pressure (CoP) complexity during gait using non-linear approximate entropy (ApEn). Method: 20 elderly women with experience of falling ($age=72.55{\pm}5.42yrs$; $height=154.40{\pm}4.26cm$; $body\;weight=57.40{\pm}6.21kg$; $preferred\;gait\;speed=0.52{\pm}0.17m/s$) and 20 elderly women with no experience of falling ($age=71.90{\pm}2.90yrs$; $height=155.28{\pm}4.73cm$; $body\;weight=56.70{\pm}5.241kg$; $preferred\;gait\;speed=0.56{\pm}0.13m/s$) were recruited for the study. While they were walking at their preferred gait speed on a treadmill (instrumented dual belt treadmills, Bertec, USA) with a force plate CoP data were collected for the 20 strides. The complexity of the CoP was analyzed using the ApEn technique. Results: The ApEn of the medial-lateral CoP in the fallers showed smaller about 16% compared to the non-fallers (p<.05). The ApEn of the antero-posterior CoP of the fallers showed smaller about 12% compared to the non-fallers, but the difference was not statistically significant. Conclusion: Based on the results of this study, the reduction of the medio-lateral CoP complexity in the elderly gait would be an index to determine the potential fall.

Resource Allocation and EE-SE Tradeoff for H-CRAN with NOMA-Based D2D Communications

  • Wang, Jingpu;Song, Xin;Dong, Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권4호
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    • pp.1837-1860
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    • 2020
  • We propose a general framework for studying resource allocation problem and the tradeoff between spectral efficiency (SE) and energy efficiency (EE) for downlink traffic in power domain-non-orthogonal multiple access (PD-NOMA) and device to device (D2D) based heterogeneous cloud radio access networks (H-CRANs) under imperfect channel state information (CSI). The aim is jointly optimize radio remote head (RRH) selection, spectrum allocation and power control, which is formulated as a multi-objective optimization (MOO) problem that can be solved with weighted Tchebycheff method. We propose a low-complexity algorithm to solve user association, spectrum allocation and power coordination separately. We first compute the CSI for RRHs. Then we study allocating the cell users (CUs) and D2D groups to different subchannels by constructing a bipartite graph and Hungrarian algorithm. To solve the power control and EE-SE tradeoff problems, we decompose the target function into two subproblems. Then, we utilize successive convex program approach to lower the computational complexity. Moreover, we use Lagrangian method and KKT conditions to find the global optimum with low complexity, and get a fast convergence by subgradient method. Numerical simulation results demonstrate that by using PD-NOMA technique and H-CRAN with D2D communications, the system gets good EE-SE tradeoff performance.

New Error Control Algorithms for Residue Number System Codes

  • Xiao, Hanshen;Garg, Hari Krishna;Hu, Jianhao;Xiao, Guoqiang
    • ETRI Journal
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    • 제38권2호
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    • pp.326-336
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    • 2016
  • We propose and describe new error control algorithms for redundant residue number systems (RRNSs) and residue number system product codes. These algorithms employ search techniques for obtaining error values from within a set of values (that contains all possible error values). For a given RRNS, the error control algorithms have a computational complexity of $t{\cdot}O(log_2\;n+log_2\;{\bar{m}})$ comparison operations, where t denotes the error correcting capability, n denotes the number of moduli, and ${\bar{m}}$ denotes the geometric average of moduli. These algorithms avoid most modular operations. We describe a refinement to the proposed algorithms that further avoids the modular operation required in their respective first steps, with an increase of ${\lceil}log_2\;n{\rceil}$ to their computational complexity. The new algorithms provide significant computational advantages over existing methods.

Super-Resolution을 위한 Deconvolution 적용 고속 컨볼루션 뉴럴 네트워크 (Fast Very Deep Convolutional Neural Network with Deconvolution for Super-Resolution)

  • 이동현;이호성;이규중;이혁재
    • 한국멀티미디어학회논문지
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    • 제20권11호
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    • pp.1750-1758
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    • 2017
  • In super-resolution, various methods with Convolutional Neural Network(CNN) have recently been proposed. CNN based methods provide much higher image quality than conventional methods. Especially, VDSR outperforms other CNN based methods in terms of image quality. However, it requires a high computational complexity which prevents real-time processing. In this paper, the method to apply a deconvolution layer to VDSR is proposed to reduce computational complexity. Compared to original VDSR, the proposed method achieves the 4.46 times speed-up and its degradation in image quality is less than -0.1 dB which is negligible.

소방조직의 구조적 특성에 관한 연구 (A Study on the Characteristics of Fire Service Organization Structure)

  • 이원주
    • 한국화재소방학회논문지
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    • 제33권1호
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    • pp.164-170
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    • 2019
  • 본 연구는 우리나라 소방조직의 구조적 특성을 분석의 요소에 따라 확인하고 규명하고자 수행되었다. 이를 위하여, 소방공무원으로 구성된 소방조직을 연구대상으로 한정하고, 조직의 구조적 특성(복잡성, 집권성, 공식성)을 선행연구와 관계법령을 이용하여 확인하였다. 연구결과, 소방조직은 복잡성, 집권성, 공식성이 모두 높은 조직구조를 갖고 있는 것으로 나타났다. 이는 전형적인 기계적 관료제적의 조직 특성으로, 일반 정부행정조직이나 기업조직에서는 찾아 볼 수 없는 소방조직만의 고유한 특성이다. 본 연구결과는 소방조직의 학술적 개념을 정립하는데 기여가 될 것으로 기대된다.

Color Dispersion as an Indicator of Stellar Population Complexity for Galaxies in Clusters

  • 이준협;박민아;이혜란;오슬희
    • 천문학회보
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    • 제43권2호
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    • pp.34.1-34.1
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    • 2018
  • We investigate the properties of bright galaxies with various morphological types in Abell 1139 and Abell 2589, using the pixel color-magnitude diagram (pCMD) analysis. The 32 bright member galaxies ($Mr{\leq}-21.3mag$) are deeply imaged in the g and r bands in our CFHT/MegaCam observations, as a part of the KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC). We examine how the features of their pCMDs depend on galaxy morphology and infrared color. We find that the g - r color dispersion as a function of surface brightness (${\mu}r$) shows better performance in distinguishing galaxy morphology, than the mean g - r color does. The best set of parameters for galaxy classification appears to be a combination of the minimum color dispersion at ${\mu}r{\leq}21.2mag\;arcsec-2$ and the maximum color dispersion at $20.0{\leq}{\mu}r{\leq}21.0mag\;arcsec-2$: the latter reflects the complexity of stellar populations at the disk component in a typical spiral galaxy. Moreover, the color dispersion of an elliptical galaxy appears to be correlated with its WISE infrared color ([4.6]-[12]). This indicates that the complexity of stellar populations in an elliptical galaxy is related to its recent star formation activities. From this observational evidence, we infer that gas-rich minor mergers or gas interactions may have usually occurred during the recent growth of massive elliptical galaxies.

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Effects of Diet Complexity and Fermented Soy Protein on Growth Performance and Apparent Ileal Amino Acid Digestibility in Weanling Pigs

  • Ao, X.;Kim, H.J.;Meng, Q.W.;Yan, L.;Cho, J.H.;Kim, I.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권11호
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    • pp.1496-1502
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    • 2010
  • Two experiments were conducted to evaluate the effects of diet complexity and fermented soy protein on growth performance and amino acid digestibility. In Exp. 1, a total of 120 crossbred weanling pigs ($5.68{\pm}0.80\;kg$ BW) were randomly allocated into 4 treatments. Each treatment had 6 replicate pens comprising 5 pigs in each replicate. Experimental diets consisted of simple (soybean meal as protein source) and complex (soybean meal, rice protein concentrate, potato protein concentrate and fish meal as protein sources) diets; each diet contained 0 or 5% fermented soy protein (FSP), respectively. Dietary treatments included: i) simple diet; ii) simple diet with 5% FSP; iii) complex diet; iv) complex diet with 5% FSP. Pigs were provided each experimental diet for 20 d (phase 1) and then fed the same common diet for 10 d (phase 2). During days 0-10, pigs fed FSP diets had greater ADG than those fed non-FSP diets (p<0.05). G/F in FSP treatments was significantly higher than that in non-FSP treatments (p<0.05) from days 0 to 10. Throughout the overall period, G/F was greater in FSP treatments compared with non-FSP treatments (p<0.05). On d 10, N digestibility was higher in pigs fed FSP diets than in those fed non-FSP diets (p<0.05). Diet complexity did not affect growth performance and nutrient digestibility (p>0.05) in this experiment. In Exp 2, 12 ileal-cannulated, weanling barrows were housed in individual metabolism crates and randomly assigned to 1 of 4 treatments (same as Exp. 1) by using a $4{\times}4$ Latin square design. Among the essential amino acids, apparent ileal digestibility (AID) of Met and Val were increased in pigs fed FSP diets compared with those fed non-FSP diets (p<0.05). AID of Met, Phe and total essential amino acids were higher in pigs fed complex diets than in those fed simple diets (p<0.05). Among the non-essential amino acids, AID of Ala in FSP treatments was greater than that in non-FSP treatments (p<0.05). In addition, Asp, Cys, Glu, Pro, Ser and total non-essential amino acid digestibilities in pigs fed complex diets were higher compared with those fed simple diets (p<0.05). Interaction was observed in AID of Met, Asp and Pro. In conclusion, these results indicated that feeding of 5% FSP to nursery pigs improved feed efficiency and AID of amino acids, and diet complexity did not maximize the growth performance of pigs in the subsequent phase.

Traffic Balance using SNMP for Multimedia Service (TBSMS) Architecture

  • Lim, Seock-Kuen;Lee, Hyun-Pyo;Lee, Jae-Yong;Lee, Kyun-Ha
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2000년도 봄 학술발표논문집 Vol.27 No.1 (A)
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    • pp.394-396
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    • 2000
  • Currently, lots of research s going on in the field of the load distribution within HTTP. RR-DNS and SWEB are the most representative load distribution research. But, there are still many problems: unbalancing of load, load increase of web server and cost increase. Also, clients that require lots of data like multimedia happens to increase network load. To solve these, research about client/agent/server architecture is going on. But, the clients must know the agent's address and there are complexity and migration problems for design of such as protocol. This paper proposes TBSMS that is capable of choosing the optimal server considering the service capacity of the server as well as the network load. This paper demonstrates that TBSMS uses the web to solve the problem that client must know the agent's address and uses SNMP to solve the complexity and migration problem.

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Theoretical study on electronic properties of deoxyfluorinating sulfur-based reagents

  • Lim, Soobin;Lee, Eunsung
    • 대한방사성의약품학회지
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    • 제2권1호
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    • pp.51-55
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    • 2016
  • Organofluorine compounds have become increasingly important as pharmaceuticals, radiopharmaceuticals, agrochemicals, and material science. Recent advances on the efficient introduction of fluorine to organic molecules are mainly results of development of transition metal catalysts and fluorination reagents. Among the various fluorination reagents, we have been interested in developing more efficient sulfur-based deoxyfluorinating reagents. Here we report various electronic properties of five popular sulfur-based deoxyfluorinating reagents using density functional theory calculation. We believe that the theoretical study on the reagents will assist the rational design of new deoxyfluorinating reagents.