• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.786-791
• /
• 2007

Statistical differences between men and women are investigated for a total of eleven joint motions during level walking. Human locomotion which exhibits nonlinear dynamical behaviors is quantified by the chaos analysis. Time series of joint motions was obtained from gait experiments with ten young males and ten young females. Body motions were captured using eight video cameras, and the corresponding angular displacements of the neck and the upper body and lower extremity were computed by motion analysis software. The maximal Lyapunov exponents for eleven joints were calculated from attractors constructed and then were analyzed statistically by one-way ANOVA test to find any difference between the genders. This study shows that sexual differences in joint motions were statistically significant at the shoulder, knee and hip joints.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.04b
• /
• pp.380-385
• /
• 1993

The demand for automatic manufacturing systems is incerasing. Computer Integrated Manufacturing(CIM) technology is believed to be a solution for the problem to enhance productivities and flexibilities. Although researches on CIM have been conducted treendously, application of the technology is not widely accepted yet. The CIM research on the shop floor starts with the Flexible Manufacturing System(FMS). One of the crucial obstacles to the FMS is the lack of excellent strategies for efficient operations. The aim of this research is constructing an automation scheme in the low level of factories where various machinaries are involved. An operating strategy is established for an automation unit named as a cell which resides between the upper level computers and manufacturing shop floor. The cell is defined to fit into the total manufacturing system. The defined cell has more functions than conventional cells. A scheduling scheme is adopted for the shop floor operations. A set of software has been developed and tested through simulations and shop floor experiments.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.277-280
• /
• 2006

This paper deals with the possibility on the hybrid power system concerning wind energy at a really existing island, Sunyoo-do in the west sea near Seamangeum. In the present stage, Diesel system produces all the electrical power of the Island. However, in the new proposed system of Diesel and wind energy, an optimized guideline for drive from the economic analysis on this hybrid system is given by a mathematical and statistical modelling with a share software HOMER (hybrid optimization model for electric renewables). After a series of analysis it has been shown that the hybrid system can reduce the total expenses as well as air pollution.

• Computers and Concrete
• /
• v.9 no.1
• /
• pp.51-61
• /
• 2012

According to the results of three-point bending tests of rubberized concrete and plain concrete, the parameters such as total fracture energy ($G_F$), initial fracture energy ($G_f$), and tensile strength ($f_t$) are obtained for concrete material. Using ABAQUS software and a bilinear softening fictitious crack model, the crack propagation process was simulated and compared to the experimental results. It is found that the increase of AE hit count has a similar trend with the increase of energy dissipation in FEM simulation. For two types of concretes, both experimental results and numerical simulation indicate that the rubberized concrete has a better fracture resistance.

• Journal of Korea Multimedia Society
• /
• v.19 no.6
• /
• pp.1065-1073
• /
• 2016

In this paper, we examined informatics textbooks for middle school students in accordance with 2009 revised curriculum through conducting both content analysis and surveys. The content analysis was analyzed the composition and contents of textbooks. Survey questionnaires were based on the authorization criteria and selection standards of informatics textbooks. The content analysis demonstrated that there were discrepancies among textbooks in areas such as the total number of pages, related material, the number of core concepts introduced in each chapter, and the application of software. The survey results showed that two sections - 'Expression and Modification' and 'Text' exhibited the most positive results, and the 'Creativity' section the least. Using the findings above, we present alternative ways to improve qualities of these textbooks.

• Proceedings of the Korea Port Economic Association Conference
• /
• 2007.10a
• /
• pp.161-173
• /
• 2007

This paper considers the problem of determining the cargo flow and the transportation mode in each trade route while satisfying the demand. Especially, the problem incorporates short sea shipping in Korea, which is becoming more important in order to improve efficiency of Logistics. The objective is to minimize the sum of shipping and inland transportation costs. To solve optimally the problem, this paper employs a linear programming model, which is an operations research technique for optimization. The problem is formulated by extending the well-known network design problem by considering capacity at seaport and limitation of total number of vehicles. The model is solved using CPLEX, a commercial linear program software. The test results using a real cargo flow data in Korea show that the model represents closely the real situation.

• Computers and Concrete
• /
• v.20 no.3
• /
• pp.297-310
• /
• 2017

A CFD software was used to simulate free surface flow of SCC in the T-Box test. In total, seven simulations were developed to study the effect of rheological parameters on the non-restricted flow performance of SCC in both horizontal and vertical directions. Different suspending fluids having five plastic viscosity values between 10 and 50 Pa.s, three yield stress values between 14 and 75 Pa, one density of $2500kg/m^3$, and one shear elasticity modulus of 100 Pa were considered for suspension of 178 spherical particles of 20-mm diameter and $2500kg/m^3$ density. The results of the simulations are found to correlate well to changes in rheological parameters of the suspending fluid. Plastic viscosity was shown to be the most dominant parameter affecting flowability and dynamic stability compared to the yield stress. A new approach was proposed to evaluate performability of SCC based on a trade-off between flowability and dynamic stability.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.55 no.5
• /
• pp.229-235
• /
• 2006

High speed PC-based DIO(Digital I/O) system that consists of a master device and slave I/O devices is developed. The PCI interfaced master device controls all of serial communications, reducing the load on the CPU to a minimum. The slave device is connected from the master device and another slave device is connected to the slave device, it can repeated to maximum 64 slave devices. The slave device has 3 types I/O mode, such as 16 bits input-only, 16 bits output-only, and 8bits input-output. The master device has 2 rings which can take 64 slaves each. Therefore, total I/O points covered by the master is 2048 points. The slave features 3 types of input/output function interchangeability by DIP switch settings. Library, application, and device driver software for the DIO system that have a secure and a convenient functionality are developed.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.10a
• /
• pp.91-91
• /
• 2001

This paper is on 3D virtual reality simulator for terminal in connection with terminal operation system in real terminal in order to reflex complicated terminal operation and environment. This simulator has been developed based on knowledge of terminal planning and operation analysis and advanced software technologies that TSB has accumulated over 10 years. In this study, the simulator generates terminal layout and component of terminal in the same environments as the real terminal in Ohi, Japan and uses real operation system using real planning data in the past in order to describe 3D VR simulation that integrates container handling equipment and real time communication of job ordering. In addition, it is suggested various statistics and analysis report can be used to derive decision supporting factors that optimize design of terminal and improve operation, which will eventually increase terminal productivity.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.800-804
• /
• 2005

Load flow and short circuit fault transients of a power distribution system with wind turbines as dispersed generation units is presented. Usage of renewable energies such as wind is already a small part of total installed power system in medium and low voltage networks. In this paper, a radial power distribution system with wind turbines is simulated using DIgSILENT PowerFactory software for their influence on load flow and short circuit fault transients. Short fault occurring in dispersed generation systems causes some problems for the system and costumers such as fault level increase or the problems of sudden fluctuations in the current, voltage, power and torque of the double fed induction machine utilized in the wind turbines which have been studied and investigated.