• Journal of Korea Multimedia Society
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• v.21 no.6
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• pp.667-677
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• 2018

Since sensor networks consist of sensor nodes with limited energy resources, so efficient energy use of sensor nodes is very important in the design of sensor networks. Sensor nodes consume a lot of energy for data transmission. Clustering technique is used to efficiently use energy in data transmission. Recently, mobile sink techniques have been proposed to reduce the energy load concentrated on the cluster header near a sink node. The CMS(Cluster-based Mobile sink) technique minimizes the generation of control messages by creating a data transmission path while creating clusters, and supports the inter-cluster one-hop transmission. But, there is a case where there is no connectivity between neighbor clusters, it causes a problem of having a long hop data transmission path regardless of local distance. In this paper, we propose a SCBC(Strong connection balancing cluster) to support the path of the minimum number of hops. The proposed scheme minimizes the number of hops in the data transmission path and supports efficient use of energy in the cluster header. This also minimizes a number of hops in data transmission paths even when the sink moves and establishes a new path, and it supports the effect of extending the life cycle of the entire sensor network.

• Advances in Computational Design
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• v.6 no.1
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• pp.1-13
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• 2021

Failure of a Multi-storeyed reinforced concrete framed structure occurs when a primary vertical structural component is isolated or made fragile, due to artificial or natural hazards. Load carried by vertical component (column) is transferred to neighbouring columns in the structure, if the neighbouring column is incompetent of holding the extra load, this leads to the progressive failure of neighbouring members and finally to the failure of partial or whole structure. The collapsing system frequently seeks alternative load path in order to stay alive. One of the imperative features of collapse is that the final damage is not relative to the initial damage. In this paper, the effect on the column and beam adjacent to statically removed vertical element in terms of axial force, shear force and bending moment is investigated. Using Alternate load path method, numerical modelling of two dimensional one bay, two bay with variation in storey heights are analysed with FE model in order to obtain better understanding of failure mechanism of multi-storeyed reinforced concrete framed structure. The results indicate that the corner column is more susceptible to progressive collapse when compared to middle column, using this simplified methodology one can easily predict how the structure can be made to stay alive in case of sudden failure of any horizontal or vertical structural element before designing.

• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.329-345
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• 2017

This paper devoted to study dynamic interaction between crack and inclusion or void by developing the eXtended Finite Element Methods (XFEM). A novel XFEM approximation is presented for these structures containing multi discontinuities (void, inclusion, and crack). The level set methods are used so that elements that include a crack segment, the boundary of a void, or the boundary of an inclusion are not required to conform to discontinuous edges. The investigation covers the effects of a single circular or elliptical void / stiff inclusion, and multi stiff inclusions on the crack propagation path under dynamic loads. Both the void and the inclusion have a significant effect on the dynamic crack propagation path. The crack initially curves towards into the void, then, the crack moves round the void and propagates away the void. If a large void lies in front of crack tip, the crack may propagate into the void. If an enough small void lies in front of crack tip, the void may have a slight or no influence on the crack propagation path. For a stiff inclusion, the crack initially propagates away the inclusion, then, after the crack moves round the inclusion, it starts to propagate along its original path. As ${\delta}$ (the ratio of the elastic modulus of the inclusion to that of the matrix) increases, a larger curvature of the crack path deflection can be observed. However, as ${\delta}$ increases from 2 to 10, the curvature has an evident increase. By comparison, the curvature has a slight increase, as ${\delta}$ increases from 10 to 1000.

• Transactions of Materials Processing
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• v.32 no.1
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• pp.35-40
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• 2023

In the case of a wire with a very fine diameter during the multi-stage drawing process, the heterogeneity of the deformation in the radial direction tends to develop strongly as the amount of deformation is accumulated. It is known that the heterogeneity of deformation in the radial direction of the wire is closely related to the process parameters during the multi-stage drawing process. In this study, finite element analysis (FEA) was used to theoretically examine the effect of friction between the surface of the wire and the drawing die during the multi-stage drawing process of Cu-0.2wt%Mg alloy on the deformation heterogeneity developed in the radial direction of the wire. The distribution of effective strain, radial strain, circumferential strain, and shear strain developed in the radial direction of the wire during the multi-stage drawing process was analyzed while changing the friction coefficient, and the results were analyzed and compared for each path and position. The FEA results revealed that the shear strain developed in the radial direction of the wire during the multi-stage drawing process of Cu-0.2wt%Mg alloy showed the most non-uniform distribution and was also severely affected by the friction coefficient.

• Korean Journal of Health Education and Promotion
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• v.21 no.3
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• pp.1-17
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• 2004

The purpose of this study is to evaluate the roles of expected self-control and expected self-control results in explaining adolescents' Internet addiction. In the study model, expectations of self-control and self-control results directly determine Internet addiction and Internet use time meditates the impacts of expectations of self-control and self-control results on Internet addiction. The study subjects are 1,080 middle and high school students in Busan. Stratified cluster sampling is applied by school type and school year. The response rate is 96%(l,037cases). This study develops the scales of expected self-control and expected self-control results. The scales of Internet addiction are devised by using the concept of functional dependency such as salience, withdrawal symptoms, mood modification, tolerance, relapse, and conflict. For verifying the study model, path analysis and multiple regression models are applied for identifying path significants and evaluating confounding effects of control variables, respectively. Moreover, multi partial F-test is performed for selecting the best regression model. Expected self-control is a significant determinant of Internet addiction and Internet use time that also significantly explains Internet addiction. The total effect of expected self-control towards Internet addiction is -.95. The total effect is comprised with the direct effect (-.71) and the indirect effect(-.24). In this result, the direct effect refers a curative effect since expected self-control directly reduces the level of Internet addiction, and the indirect effect refers a preventive effect because self-control can reduce time of Internet use that is a direct determinant of Internet addiction. In the test of the confounding effects of control variables, there are no confounding effects in the models of multiple regression. It implies a robustness of the study model as regards control variables. In conclusion, improving adolescents' expected self-control can control Internet addiction level. This finding implies that a health promotion program for improving expected self-control can be a cost effective method compared to other approaches.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12C
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• pp.1192-1199
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• 2003

In this paper, we investigate the effect of pulse repetition frequency (PRF) and slot interval on the throughput performance of the ultra wide band (UWB) wireless communication system in multi-path channels, and based on these observations, a data throughput control using PRF and slot interval is proposed for maximizing the effective throughput. Recently, due to many desirable features of the UWB system, it has drawn much attention especially for short-range high-speed data transmission. The UWB system has two parameters to determine its data throughput; pulse repetition frequency and slot interval. In the multi-path channel with additive white Gaussian noise, the UWB system suffers from the inter-pulse interference (IPI) and noise, which result in degradation of system performance. The UWB system can vary the two parameters to maintain and/or improve the system performance. In this paper, we demonstrate the effects of the two parameters on the data throughput of the UWB system in various multi-path indoor channels through computer simulation, and show that the variable data rate approach designed based on the observations is superior to the fixed data rate one in terms of effective throughput performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.60-67
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• 2010

In the ubiquitous age, applications of wireless personal area network (WPAN) technology using LEDs are in progress. However, visible light communications (VLC) using the LEDs have weakness which deteriorate performance of communication because of multi-path fading that occurs propagation delay by interior walls or other things in indoor environments. In this paper, orthogonal frequency division multiplexing (OFDM) scheme is adapted to decrease multi-path fading and multi-path dispersion and to provide high speed data transmission. Besides, to reduce information losses caused by optical noise (incandescent lamps, fluorescent lamps, sunbeam etc.) also proposed channel coding using turbo codes. The encoding and decoding of the proposed system is described, and simulation results are analyzed. We can know that performance of proposed system is increased about 4 [dB] through the simulation results. Also, when the system take doppler effect, the system performance worsened.

• Fashion & Textile Research Journal
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• v.24 no.4
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• pp.431-442
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• 2022

Despite the rapid reorganization of the center of consumption online, the fashion industry is still strengthening brand marketing using offline stores. This study investigates the psychological mechanisms of shopping flow by three mediators that influence the e-word of mouth(e-WOM) as a marketing performance variable in recent marketing. Data collection was conducted online for 241 women in their 20s and 30s. The significance of multi-mediated pathways was verified using Process 3.5 Model 6. The results for multiple mediation paths are as follows. First, the direct effect of shopping flow on brand advocacy was not significant. Second, analysis of the significance of the indirect effect via simple mediation found that the path mediated by shopping value in the path from the shopping flow to brand advocacy was significant. Third, analysis of the indirect effect by double mediation revealed all three double mediating effects of shopping flow on brand advocacy were significant(emotional response and shopping value, emotional response and store attachment, shopping value and store attachment). Fourth, analysis of the significance of the indirect effect by sequential multiple mediation established the indirect effect leading to emotional response, shopping value, and store attachment was significant. These results indicate that the operation of an experiential fashion store is not just a means for sales, but a communication tool that improves and promotes the brand advocacy by providing brand experience in a store.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.179-186
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• 2011

Wireless Mesh Network technology refers to the technology which establishes wireless network whose transmission speed is similar to that of the wire system, and provides more enhanced flexibility in the building of network, compared to the existing wired network. In addition, it has the feature of less mobility and less restriction from the energy effect. However, there follow many considerations such as system overhead in the case of setting or the selection of multi-path. Accordingly, the focus is on the design and optimization of network which can reflect this network feature and the technology to establish path. This paper suggests the methods on the programming of path in Wireless Mesh Network routing by applying the evaluation value of node service, making use of the loss rate of data, the hop count of bandwidth and link and the traffic status of node, considering the performance of link and load in the fitness evaluation function, in order to respond to the programming of multi-path effectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.78-91
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• 2017

In this study, we conducted a comparative study on user's perception and behavior on public system service (PSS) using institutionalism theory and MGA (multi-group analysis) methodology. In particular, this study focuses on how institutional isomorphism is applied to public system services and how MGA can be implemented correctly in a variance based SEM (structural equation model) such as PLS (partial least square). A data set of 496 effective responses was collected from pubic system users and an empirical research was conducted using three segmented models categorized by public proximity theory (public firms = 113, government contractors = 210, private contractors = 173). For rigorous group comparisons, each model was estimated by the same indicators and approaches. PLS-SEM was used in testing research hypotheses, followed by parametric and non-parametric PLS-MGA procedures in testing categorical moderation effects. This study applied novel procedures for testing composite measurement invariance prior to multi-group comparisons. The following main results and implications are drawn : 1) Partial measurement invariance was established. Multi-group analysis can be done by decomposed models although data can not be pooled for one integrated model. 2) Multi-group analysis using various approaches showed that proximity to public sphere moderated some hypothesized paths from quality dimensions to user satisfaction, which means that categorical moderating effects were partially supported. 3) Careful attention should be given to the selection of statistical test methods and the interpretation of the results of multi-group analysis, taking into account the different outcomes of the PLS-MGA test methods and the low statistical power of the moderating effect. It is necessary to use various methods such as comparing the difference in the path coefficient significance and the significance of the path coefficient difference between the groups. 4) Substantial differences in the perceptions and behaviors of PSS users existed according to proximity to public sphere, including the significance of path coefficients, mediation and categorical moderation effects. 5) The paper also provides detailed analysis and implication from a new institutional perspective. This study using a novel and appropriate methodology for performing group comparisons would be useful for researchers interested in comparative studies employing institutionalism theory and PLS-SEM multi-group analysis technique.