• The Journal of Korean Association of Computer Education
• /
• v.7 no.1
• /
• pp.15-25
• /
• 2004

In this study, we present an assessment model for the 'Information Society and Computer' subject of the 7th National High School Curriculum. The Assessment model is developed to improve the quality of the curriculum by considering both of the objective of the National Curriculum and the property of the subject. To develop the assessment model, we analyzed textbooks used in most schools, developed achievement standards, classified assessment areas and standards. Adequacy and potential practice of the assessment model is also reviewed and evaluated by subject experts.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.5
• /
• pp.449-455
• /
• 2016

This study provides the finite-element (FE) squeal-model predicting friction-induced noise with respect to several friction materials that have different friction characteristics. The friction curve and the corresponding friction noise were measured for four friction materials (Cu, Ni, Al, Mg) using the pin-on-disk and reciprocating friction system. The slope of the friction curve linearized at the sliding velocity was applied to the FE model. The unstable modes in the complex eigenvalue analysis were shown to correspond to the squeal frequencies that existed in the experiment.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.10 no.1
• /
• pp.47-56
• /
• 1990

An inverse self-iterative procedure is developed to estimate layer moduli and stresses in cement concrete pavement systems from the falling weight deflectometer deflection basins. The existing concrete pavement highways are analyzed using coupled analysis procedure of finite element and layer elastic theory for models obtained through factorial design, from which the characteristics of deflection basins are studied and the empirical equations are proposed for the estimation of layer moduli. The empirical equations are used to assume initial moduli, and the relations between the rate of change of moduli and deflections are used in the self-iterative procedure to ensure accuracy of moduli. The developed computer program of this procedure is verified through various numerical model tests.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.6
• /
• pp.38-46
• /
• 2011

In order to simulate the ignition-gas injection in the interior ballistics, a two-dimensional analytic code for two-phase flows has been developed. The Eulerian-Lagrangian approach and the low-dissipation simple high-resolution upwind scheme(LSHUS) have been adopted in the numerical code for the propellant combustion of the gun propelling charges. The ghost-cell extrapolation method has been used for the moving boundary in the chamber with the projectile movement. The calculation results of the developed code have been compared and verified through those of the dimensionless IBHVG2 code and the previous one-dimensional code. In comparison with the two-phase flows according to the drag models, the numerical analysis of the muzzle velocity has been affected by the drag model.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.3
• /
• pp.91-97
• /
• 2001

Since the new field information of target signal is important in the development and verification of active sonar system, experimental method and simulation technique are widely used in order to analyze the detail characteristics of target scattered echoes. Therefore, in this paper, the scale target experiment is performed to develope and Improve the target signal simulation model. Since the experimental results show that the specular reflection is the major component among scattering mechanisms, the target signal simulation model based on the Geometric Optics Theory (GOT) is developed. Complex target is separated into simple shapes, known as canonical shape. The contribution from individual canonical shapes are summed with proper phase and amplitude to produce the target strength of the whole complex body. Simulated target signal is compared with the experimental results and discussed.

• 전자공학회논문지 IE
• /
• v.46 no.4
• /
• pp.8-15
• /
• 2009

In this paper, we are indicated CMOS Image sensor circuit SPICE analysis for the Photo Diode and pixel Modeling. We get a characteristic of the photoelectric current using a device simulator Medici and develop the Photodiode model for applying a SPICE simulation. For verifying the result, We compared the result of SPICE simulation with the result of mixed mode simulation about the testing circuit structure consisted photodiode and NMOS.

• Nuclear Engineering and Technology
• /
• v.27 no.6
• /
• pp.833-844
• /
• 1995

In self-tuning predictive control algorithm for steam generator is presented. The control algorithm is derived by suitably modifying the generalized predictive control algorithm. The main feature of the unposed method relies on considering the measurable disturbance and a simple adaptive scheme for obtaining the controller gain when the parameters of the plant are unknown. This feature makes the proposed approach particularly appealing for water level control of steam generator when measurable disturbance is used. In order to evaluate the performance of the proposed algorithm, computer simulations are done for an PWR steam generator model. Simulation result show satisfactory performances against load variations and steam flow rate estimation errors. It can be also observed that the proposed algorithm exhibit better responses than a conventional PI controller.

• International Journal of Highway Engineering
• /
• v.6 no.3 s.21
• /
• pp.55-64
• /
• 2004

Maximum dry unit weight, ${\gamma}_{dmax}$, is the most important engineering properties for subgrade soil. Existing models to predict ${\gamma}_{dmax}$ containing many parameters, seem to be rather complex. This paper presents new simple models to predict ${\gamma}_{dmax}$. for sandy soils, A number of sieve analysis and compaction tests for 36 types of sands were conducted to develop the regression-based models. Parameters used to estimate ${\gamma}_{dmax}$ are both the geometric mean and geometric standard deviation of the soils, or the particle-size distribution curve parameters. Maximum dry unit weights predicted by the models are in good agreement with the laboratory measurements for the soil samples obtained at 16 locations within the Korea.

• Journal of Korean Society of Transportation
• /
• v.20 no.5
• /
• pp.145-152
• /
• 2002

Real-time queueing information and/or predictive queue built-up information can be a good criterion in selecting travel options, such as routes, both for users, and for operators in operating transportation system. Provided properly, it will be a key information for reducing traffic congestion. Also, it helps drivers be able to select optimal roues and operators be able to manage the system effectively as a whole. To produce the predictive queue information, this paper proposes a predictive model for estimating and predicting queue lengths, mainly based on Kalman Filter. It has a structure of having state space model for predicting queue length which is set as observational variable. It has been applied for the Namsan first tunnel and the application results indicate that the model is quite reasonable in its efficacy and can be applicable for various ATIS system architecture. Some limitations and future research agenda have also been discussed.

• The Journal of the Korea Contents Association
• /
• v.12 no.1
• /
• pp.59-67
• /
• 2012

Software change management is focused on the change of a entity like the change of contents of a system or a document. In change management, interactive relationship among requirements and complex decision making is needed to obtain optimized status. In this paper we design a management model of software change management in distributed environment which mange the change among components by time and situation. In addition, each components are defined and use ANP technique for best decision-making by using the subordinate relationship and feedback considering the mutual dependency referring the change of components in distributed environment. Thus, we analyze the dependency among each components and show 3 types of change relationship. Also through analysis of dependency, we verified the effectiveness of such approach.