• Title/Summary/Keyword: Time-dependency

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Interprocedural Transformations for Parallel Computing

  • Park, Doo-Soon;Choi, Min-Hyung
    • Journal of Korea Multimedia Society
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    • v.9 no.12
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    • pp.1700-1708
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    • 2006
  • Since the most program execution time is consumed in a loop structure, extracting parallelism from loop programs is critical for the taster program execution. In this paper, we proposed data dependency removal method for a single loop. The data dependency removal method can be applied to uniform and non-uniform data dependency distance in the single loop. Procedure calls parallelisms with only a single loop structure or procedure call most of other methods are concerned with the uniform code within the uniform data dependency distance. We also propose an algorithm, which can be applied to uniform, non-uniform, and complex data dependency distance among the multiple procedures. We compared our method with conventional methods using CRAY-T3E for the performance evaluation. The results show that the proposed algorithm is effective.

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Extracting Maximum Parallelism for Parallel Computing (병렬 계산을 위한 최대 병렬성 추출 방법)

  • Park, Doo-Soon
    • The Journal of Korean Association of Computer Education
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    • v.8 no.1
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    • pp.93-103
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    • 2005
  • Since the most program execution time is consumed in a loop structure, extracting parallelism from sequential loop programs is critical for the faster program execution. Conventional studies for extracting the parallelism are focused mostly on a uniform data dependence distance. In this paper, we proposed data dependency elimination method for a nested loop and extended data dependency elimination method to extract parallelism from the loop with procedure calls. The data dependency elimination method and the extended data dependency elimination method can be applied to uniform and non-uniform data dependency distance. We compared our method with conventional methods using CRAY-T3E for the performance evaluation. The results show that the proposed algorithms are very effective.

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Factors Influencing Nicotine Dependency among College Students Intending to Quit Smoking (금연준비단계 대학생의 니코틴의존도 영향요인)

  • Lee, Hea Shoon;Song, Mi Ryeong
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.20 no.4
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    • pp.429-437
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    • 2013
  • Purpose: The purpose of this study was to identify factors influencing nicotine dependency among college students intending to quit smoking, and to provide data for the construction of programs that will be successful in helping the students quit smoking. Method: In this study a cross-sectional survey to analyze was used. The data were collected between April 22 and April 24, 2013 from 218 college students who had unsuccessfully tried to quit smoking in the past but were now intending to try and quit smoking again. Data were analyzed using frequency, independent t-test, one-way ANOVA and multiple regression with the SPSS 21.0. Results: Factors influencing nicotine dependency were self-efficacy for smoking abstinence (t=-6.60, p=<.001), length of time since beginning to smoke (t=5.39, p<.001), level of carbon monoxide intake (t=2.38, p=.018), and withdrawal symptoms as reasons why the students failed to quit smoking (t=2.22, p=.028). These 4 variables accounted for 35.0% of the variance with regard to nicotine dependency. Conclusions: To conduct a successful program for students who intend to quit smoking, self-efficacy for smoking abstinence, length of time since beginning to smoke, level of carbon monoxide, and withdrawal symptoms as reasons for failing to quit smoking should be considered.

Numerical analysis of embankment primary consolidation with porosity-dependent and strain-dependent coefficient of permeability

  • Balic, Anis;Hadzalic, Emina;Dolarevic, Samir
    • Coupled systems mechanics
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    • v.11 no.2
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    • pp.93-106
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    • 2022
  • The total embankment settlement consists of three stages: the initial settlement, the primary consolidation settlement, and the secondary consolidation settlement. The total embankment settlement is largely controlled by the primary consolidation settlement, which is usually computed with numerical models that implement Biot's theory of consolidation. The key parameter that affects the primary consolidation time is the coefficient of permeability. Due to the complex stress and strain states in the foundation soil under the embankment, to be able to predict the consolidation time more precisely, aside from porosity-dependency, the strain-dependency of the coefficient of permeability should be also taken into account in numerical analyses. In this paper, we propose a two-dimensional plane strain numerical model of embankment primary consolidation, which implements Biot's theory of consolidation with both porosity-dependent and strain-dependent coefficient of permeability. We perform several numerical simulations. First, we demonstrate the influence of the strain-dependent coefficient of permeability on the computed results. Next, we validate our numerical model by comparing computed results against in-situ measurements for two road embankments: one near the city of Saga, and the other near the city of Boston. Finally, we give our concluding remarks.

CONSTRUCTABILITY IMPLEMENTATION MODEL USING DEPENDENCY STRUCTURE MATRIX

  • Youngjib Ham;Moonseo Park;Hyun-Soo Lee
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.550-555
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    • 2011
  • Utilizing construction knowledge and experiences in design phase can reduce change orders and improve productivity in construction phase. To do so, information must be made available to the design team in time. Current approaches for effective utilization of constructability knowledge, however, only focus on the formalization of constructability knowledge such as a checklist, which lacks the consideration of the appropriate use at the proper point in time. The inadequate use of constructability knowledge can result in unnecessary reworks. To deal with this problem, the design team needs to know what constructability knowledge is required for specific design activities in the design process. This paper presents a constructability implementation model using the dependency structure matrix (DSM) that focuses on information flows between design activities and constructability knowledge. For this objective, design activities in the design process are modeled in a matrix form based on their dependency. Then, constructability knowledge, which needs to be considered in the design stage, is mapped into activities and incorporated into the matrix, creating Constructability-DSM (C-DSM). Next, the partitioning algorithm is applied to C-DSM for optimal information flow. The Partitioned C-DSM is then analyzed based on the relationship between activities. Finally, the optimal utilization of construction knowledge in the design process is determined by identifying what constructability knowledge is required for each design activity, and how and when it is reflected to design for constructability. Thus, this research can help provide robust control actions to reduce unnecessary iterative cycles in design process for efficient constructability implementation.

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An Efficient Multiprocessor Implementation of Digital Filtering Algorithms (다중 프로세서 시스템을 이용한 디지털 필터링 알고리즘의 효율적 구현)

  • Won Yong Sung
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.28B no.5
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    • pp.343-356
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    • 1991
  • An efficient real-time implementation of digital filtering algorithms using a multiprocessor system in a ring network is investigated. The development time and cost for implementing a high speed signal processing system can be considerably reduced because algorithm are implemented in software using commercially available digital signal processors. This method is based on a parallel block processing approach, where a continuously supplied input data is divided into blocks, and the blocks are processed concurrently by being assigned to each processor in the system. This approach not only requires a simple interconnection network but also reduces the number of communications among the processors very much. The data dependency of the blocks to be processed concurrently brings on dependency problems between the processors in the system. A systematic scheduling method has been developed by using a processors which can be used efficiently, the methods for solving dependency problems between the processors are investigated. Implementation procedures and results for FIR, recursive (IIR), and adaptive filtering algorithms are illustrated.

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Longitudinal and Complex Influence of Academic Strain on Unhappiness and Mobile Phone Dependency among Adolescents using Latent Growth Model (잠재성장모형을 사용한 청소년의 학업긴장이 불행감과 휴대전화 의존에 미치는 종단적·복합적 영향 분석)

  • Jun, Sang-min
    • Journal of Digital Convergence
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    • v.14 no.12
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    • pp.293-302
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    • 2016
  • The study explores how academic strain, unhappiness, and mobile phone dependency among adolescents have changed over time. And we conducted the longitudinal and complex analysis on the influence of academic strain on unhappiness and mobile phone dependency in order to search the ways to prevent a vicious circle among them. We used general strain theory as a conceptual research frame and analysed the data of 1,589 respondents of the 2nd~4th Korean Children and Youth Panel with latent growth modeling. It was found that the levels of academic strain, unhappiness, and mobile phone dependency among adolescents were linearly increased across time. Academic strain initial status positively affected unhappiness initial status and both the initial status and change rate of mobile phone dependency. The change rate of unhappiness positively affected that of mobile phone dependency. Academic strain change rate positively influenced that of mobile phone dependency mediated by unhappiness change rate. We provided useful implications to academic activities, negative emotions, and mobile phone dependency for adolescents and suggested future studies about reasons of the changes of those variables.

Response analysis of soil deposit considering both frequency and strain amplitude dependencies using nonlinear causal hysteretic damping model

  • Nakamura, Naohiro
    • Earthquakes and Structures
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    • v.4 no.2
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    • pp.181-202
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    • 2013
  • It is well known that the properties of the soil deposits, especially the damping, depend on both frequency and strain amplitude. Therefore it is important to consider both dependencies to calculate the soil response against earthquakes in order to estimate input motions to buildings. However, it has been difficult to calculate the seismic response of the soil considering both dependencies directly. The author has studied the time domain evaluation of the frequency dependent dynamic stiffness, and proposed a simple hysteretic damping model that satisfies the causality condition. In this paper, this model was applied to nonlinear analyses considering the effects of the strain amplitude dependency of the soil. The basic characteristics of the proposed method were studied using a two layered soil model. The response behavior was compared with the conventional model e.g. the Ramberg-Osgood model and the SHAKE model. The characteristics of the proposed model were studied with regard to the effects of element divisions and the frequency dependency that is a key feature of the model. The efficiency of the model was confirmed by these studies.

A tensile criterion to minimize FE mesh-dependency in concrete beams under blast loading

  • Gang, HanGul;Kwak, Hyo-Gyoung
    • Computers and Concrete
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    • v.20 no.1
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    • pp.1-10
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    • 2017
  • This paper focuses on the mesh-size dependency in numerical simulations of reinforced concrete (RC) structures subjected to blast loading. A tensile failure criterion that can minimize the mesh-dependency of simulation results is introduced based on the fracture energy theory. In addition, conventional plasticity based damage models for concrete such as the CSC model and the HJC model, which are widely used for blast analyses of concrete structures, are compared with the orthotropic model that adopts the introduced tensile failure criterion in blast tests to verify the proposed criterion. The numerical predictions of the time-displacement relations at the mid-span of RC beams subjected to blast loading are compared with experimental results. The analytical results show that the numerical error according to the change in the finite element mesh size is substantially reduced and the accuracy of the numerical results is improved by applying a unique failure strain value determined by the proposed criterion.

Design Process Systematization of Transmission-Lever Using the DSM (DSM(Design Structure Matrix)을 이용한 Transmission-Lever 설계과정의 체계화)

  • 천준원;박지형;김태수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.763-767
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    • 2002
  • This paper explores a structuring method for solid modeling processes of an automobile automatic transmission-lever design. The aim of this work is to establish standard procedures to minimize iterations and trial and errors during the product development process to increase development time and costs. The design of the transmission-lever is periodically required to be changed with the model change of an automobile. The transmission-lever design process has mainly depended on the designer's experience. It causes to make difficulties to handle the dependency of components. The design process can be improved by resolving the dependency problem using the DSM. The process of applying the DSM provides a systematic way for the solid modeling of transmission-lever by the consideration of geometry dependency.

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