• Journal of the Korea Convergence Society
• /
• v.11 no.5
• /
• pp.341-351
• /
• 2020

This study aimed to identify the parenting competence and parenting stress of nurses in general hospital with preschool children, and to identify convergent factors affecting career commitment. A cross-sectional design was used with a convenience sample of 214 nurses from seven general hospitals. Data were collected through self-evaluation questionnaires from August 10 to August 31, 2016 and analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficient, and structural modelling using the SPSS WIN 18.0 and AMOS 18.0 computer programs. Parenting stress had a full mediating effect on the influence of parenting competency on career commitment. It is expected to be used as a basic data for improving career commitment of nurses in general hospitals with preschool children, and further studies on factors affecting career commitment, including job-related characteristics, along with parenting-related factors, will be needed.

• Coupled systems mechanics
• /
• v.8 no.2
• /
• pp.169-184
• /
• 2019

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.11
• /
• pp.921-933
• /
• 2018

There is a method to enhance the pure navigation performance of INS(Inertial Navigation System) through the rotation of inertial measurement unit to compensate error sources of inertial sensors each other and that INS using this principle of operation is called rotational INS. In this paper, the exact error analysis of rotational INS based on ring laser gyro considering the coupling effect with gravity and earth rate is performed to evaluate the navigation performance by inertial sensor error sources. And error analysis and performance evaluation result confirmed by modelling and simulation is also proposed in this paper.

• Smart Structures and Systems
• /
• v.33 no.2
• /
• pp.119-131
• /
• 2024

Drift angle is a significant index for diagnosing post-event structures. A common way to estimate this drift response is by using modal parameters identified under natural excitations. Although the modal parameters of shear structures cannot be identified accurately in the real environment, the identification error has little impact on the estimation when measurements from several floors are used. However, the estimation accuracy falls dramatically when there is only one accelerometer. This paper describes the susceptibility of single sensor identification to modelling error and simulations that preliminarily verified this characteristic. To make a robust evaluation from measurements of one floor of shear structures based on imprecisely identified parameters, a novel scheme is devised to approximately correct the mode shapes with respect to fictitious frequencies generated with a genetic algorithm; in particular, the scheme uses constrained minimization to take both the mathematical aspect and the realistic aspect of the mode shapes into account. The algorithm was validated by using a full-scale shear building. The differences between single-sensor and multiple-sensor estimations were analyzed. It was found that, as the number of accelerometers decreases, the error rises due to insufficient data and becomes very high when there is only one sensor. Moreover, when measurements for only one floor are available, the proposed method yields more precise and appropriate mode shapes, leading to a better estimation on the drift angle of the lower floors compared with a method designed for multiple sensors. As well, it is shown that the reduction in space complexity is offset by increasing the computation complexity.

• Journal of the Korea Convergence Society
• /
• v.8 no.8
• /
• pp.17-26
• /
• 2017

CPV system is composed with CPV cells, modules, PCS(power conditioning system), solar tracker, system installation and balance of systems(BOS). Mention about modelling method which is applied for CPV system simulation and evaluation system analysis. This paper focuses on CPV system modeling and optimal design of the electric energy production analysis through the development of proposed optimal CPV system simulation. Calculated simulation results of the generalized CPV system in regard to loss parameter calculation method can make out optimal configuration of CPV system with high reliability and stability. The loss parameter calculation method establish a mathematical modeling for the purposed of simulation and utilization various data for economical analysis of the CPV system design.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.4349-4358
• /
• 2012

ASRP(Ammunition Stockpile Reliability Program) Data is stored and operated in the field of evaluating the ammunition is not only the only field data but also the ammunition performance-oriented data can determine objectively the power of the artillery. However, ASRP has been used as a yardstick to judge the status of ammunitions stockpiled in the field. On the other hand re-evaluation of the accumulated data and in-depth research have not been carried out. A Study on the Effective Management of Artillery Ammunition using ASRP data suggests how to utilize the ASRP data to analyze and manage existing artillery forces whose focus is centered on increasing the performance of artillery ammunitions through setting the test intervals of deployed stockpiled ammunitions, forecasting the shelf-life of ammunitions, and analyzing the effectiveness of the military strength through modelling and simulation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.9 no.3
• /
• pp.299-307
• /
• 2007

In this study, a new concept for simulating a physical damage of tunnel shotcrete lining due to a long-term chemical deterioration has been proposed. It is known that the damage takes place mainly by internal cracks, reduction of stiffness and strength, which results mainly from volume expansion of the lining and corrosion of cement materials, respectively. This damage mechanism of shotcrete lining appears similar in most kinds of chemical reactions in tunnels. Therefore, the mechanical deterioration mechanism induced by a series of chemical reactions was generalized in this study and mathematically formulated in the framework of thermodynamics. The numerical model was implemented to a 3D finite element code, which can be used to simulate behaviour of tunnel structures undergoing external loads as well as chemical deterioration in time. A number of illustrative examples were given to show a feasibility of the model in tunnel designs.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.4
• /
• pp.1-6
• /
• 2020

This paper proposes the design of an advanced S-Box for calculating multiplicative inverse in AES encryption process. In this approach, advanced S-box module is first designed based on composite field, and then the performance evaluation is performed for S-box with multi-stage pipelining architecture. In the proposed S-Box architecture, each module for multiplicative inverse is constructed using combinational logic for realizing both small-area and high-speed. Through logic synthesis result, the designed 3-stage pipelined S-Box shows speed improvement of about 28% compared to the conventional method. The proposed advanced AES S-Box is performed modelling at the mixed level using Verilog-HDL, and logic synthesis is also performed on Spartan 3s1500l FPGA using Xilinx ISE 14.7 tool.

• Structural Engineering and Mechanics
• /
• v.87 no.1
• /
• pp.47-56
• /
• 2023

Any pre-existed delamination defect present during manufacturing or induce during service loading conditions in the wingskin adherend invariably shows a greater loss of structural integrity of the spar wingskin joint (SWJ). In the present study, inter-laminar delamination propagation at the critical location of the SWJ has been carried out using contact and multi-point constraint finite elements available with commercial FE software (ANSYS APDL). Strain energy release rates (SERR) based on virtual crack closure technique have been computed for evaluation of the opening (Mode-I), sliding (Mode-II) and cross sliding (Mode-III) modes of delamination by sequential release of multi point constraint elements. The variations of different modes of SERR are observed to be significant by considering varied delamination lengths, material properties of adherends and radius of curvature of the SWJ panel. The SERR rates are seen to be much different at the two pre-embedded delamination ends. This shows dissimilar delamination propagation rates. The maximum is seen to occur in the delamination front in the unstiffened region of the wingskin. The curvature geometry and material anisotropy of SWJ adherends significantly influences the SERR values. Increase in the SERR values are observed with decrease in the radius of curvature of wingskin panel, keeping its width unchanged. SWJs made with flat FRP composite adherends have superior resistance to delamination damage propagation than curved composite laminated SWJ panels. SWJ made with Boron/Epoxy (B/E) material shows greater resistance to the delamination propagation.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.1
• /
• pp.121-127
• /
• 2010

This paper relates with the improved CMA blind adaptive equalization algorithm which uses the constellation matching method that improve the inverse modelling efficiency of a communication channel compared to the present CMA blind adaptive equalizer. The amplitude distortion can be compensated in the present CMA blind adaptive equalizer which is used for the reduction of intersymbol interference by distortion that generate such as a band limited wireless mobile channel, but in the improved adaptive alogorithm operates with the minimize the amplitude phase distortion in the output of equalizer by applying the cost function that is composition of additional signal constellation matching error terms. In order to evaluation of the inverse modeling efficiency of improved algorithm, the residual intersymbol interference and recovered signal constellation were compared by computer simulation. As a result of comparion of computer simulation, the improved algorithm has a good stability in the residual intersymbol interference in the steady state, but it has a slow convergence rate in the adaptation state in initial state.