• International Journal of CAD/CAM
• /
• v.6 no.1
• /
• pp.19-27
• /
• 2006

To survive in the current shipbuilding industry it is of vital importance for shipyards to achieve an optimal utilization of resources, make an achievable planning and ensure that this planning is kept. Possible problems should be eliminated before production starts and if unexpected disturbances occur in the actual production the right measures should be taken. Due to the dynamic nature of the production process, the continuous variation in products and the complexity of both, all this can hardly be achieved with conventional static planning and analysis systems. Simulation provides a solution here, since this enables the modelling and evaluation of the dynamic relations between product and production process. After a global introduction to production simulation in general and the application of simulation at the Flensburger shipyard, this paper presents a tool that has been developed to simulate the various complex assembly processes taking place at shipyards. Subsequently the simulation model for the subassembly production at Flensburger, in which this tool is applied, will be discussed.

• Geomechanics and Engineering
• /
• v.23 no.6
• /
• pp.547-560
• /
• 2020

This paper studies the dynamic foundation-soil-foundation interaction for two square rigid foundations embedded in a viscoelastic soil layer. The vibrations come from only one rigid foundation placed in the soil layer and subjected to harmonic loads of translation, rocking, and torsion. The required dynamic response of rigid surface foundations constitutes the solution of the wave equations obtained by taking account of the conditions of interaction. The solution is formulated using the frequency domain Boundary Element Method (BEM) in conjunction with the Kausel-Peek Green's function for a layered stratum, with the aid of the Thin Layer Method (TLM), to study the dynamic interaction between adjacent foundations. This approach allows the establishment of a mathematical model that enables us to determine the dynamic displacements amplitude of adjacent foundations according to their different separations, the depth of the substratum, foundations masss, foundations embedded, and the frequencies of excitation. This paper attempts to introduce an approach based on a polynomial mathematical tool conducted from several results of numerical methods (BEM-TLM) so that practicing civil engineers can evaluation the dynamic foundations displacements more easy.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.6
• /
• pp.923-932
• /
• 2019

VE is used as a powerful tool to add value to facilities by improving functionality and reducing costs. By identifying the client's requirements in the VE process and reflecting them in the quality model, the developed alternatives meet the client's requirements. However, there is no process to verify how the developed alternatives reflect the needs of the client through functional analysis, idea generation and evaluation. The purpose of this study was to develop, verify, and prove the effectiveness of a methodology for evaluating client satisfaction with alternatives developed during the VE Job Plan. The KANO model, which can identify the satisfaction and dissatisfaction of requirements in product planning, was set as a methodology for alternative verification procedures of VE, and was improved and applied to the purpose of this study. As a result, the alternative evaluation method developed in this study was found to be useful. It is expected that the KANO model will be used to evaluate the satisfaction of VE alternatives in the VE Job Plan analysis.

• The KSFM Journal of Fluid Machinery
• /
• v.19 no.5
• /
• pp.35-41
• /
• 2016

This paper deals with the design, manufacturing and test evaluation of a hydrostatic bearing applied to a hydraulic model turbine. The design parameters of a hydrostatic bearing, considering machining and assembly tolerances, and recommended values of design parameters are presented. Also the simple design procedure of a hydrostatic bearing by utilizing the reference results is proposed. In order to illustrate the utility and validity of the proposed design procedure, two hydrostatic bearings are manufactured and test evaluation of these bearings are performed. In results, the proposed design procedure can be utilized as an effective tool at the initial design screen of a hydrostatic bearing. However, the 2D bearing governing equation should be solved to obtain the optimal design of a hydrostatic bearing.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.1 s.256
• /
• pp.70-76
• /
• 2007

Elastic-plastic fracture mechanics is popularly used for integrity evaluation of major components, however, it is not easy to extract standard specimens from operating facility. This paper examines how ductile fracture toughness is characterized by a small punch testing technique in conjunction with finite element analyses incorporating a damage model. At first, micro-mechanical parameters constituting Rousselier model are calibrated for typical nuclear materials using both estimated and experimental load-displacement (P-$\delta$) curves of miniaturized specimens. Then, fracture resistance (J-R) curves of relatively larger standard CT specimens are predicted by finite element analyses employing the calibrated parameters and compared with corresponding experimental ones. It was proven that estimated results by the proposed method using small punch specimen is promising and might be used as a useful tool for ductile crack growth evaluation.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.27 no.3
• /
• pp.117-126
• /
• 1990

In the early stage of ship design process large number of alternative compartment layout designs are generated and examined iteratively. Therefore, the design efficiency will be considerably enhanced if a tool is available to perform this kind of iterative design process effectively in a relatively short time. This paper describes a method for generating and evaluating various alternative compartment layout designs in a personal computer. In this method, computer model of a compartment layout is generated by establishing the hierarchical structure of the entities forming a compartment and defining clearly the relationships among the entities. The evaluation of the design alternatives are effectively performed utilizing the computer model generated. The data structure for storing the defined compartment layout is explained and an illustrative example is given showing the application of the method to the design and evaluation of compartment layout of an Oceanographic Research Vessel.

• Korean Journal of Clinical Pharmacy
• /
• v.19 no.2
• /
• pp.81-88
• /
• 2009

Objectives: With more and more health economic evaluations being performed in many countries, the question of whether the results from the foreign studies can be transferred to other country is becoming important. The objective of this study was to conduct a case study using three transferability diagnosis tools for economic evaluation on rheumatoid arthritis. Methods: Three diagnosis tools were used to assess transferability: Welte's tool, Boulenger's and Urdahl's. Five researchers who have experience on economic evaluation made consensus on the evaluation through the semi-delphi method. Results: With Welte's tool, absolute and relative prices in healthcare, practice variation, health-status preference, productivity and work-loss time were evaluated as biased. The transferability information score by Boulenger's was 85.9%, which means qood quality reporting. In case of Urdahl's, research questions were well defined and reporting was transparent and explicitly stated. However, both the relevance of data inputs to Korea and robustness of model were relatively low. In conclusion the UK study on rheumatoid arthritis could be partially transferable to Korea, and will need modeling-based adjustments.

• Journal of Advanced Navigation Technology
• /
• v.28 no.1
• /
• pp.95-101
• /
• 2024

This paper aims to establish a reconfigurable flight simulation environment to conduct safety evaluation of various electric vertical take-off and landing (eVTOL) aircraft. Since the inceptor, aircraft dynamics model, and controller applied to each eVTOL aircraft are different, it was configured to be variable so that a simulation can be executed for each eVTOL aircraft. Test elements and performance indicators were set to perform safety evaluation of eVTOL aircraft. Ground auxiliary equipments were designed and implemented in a simulation environment according to test procedures for each test element. In addition, to analyze safety performance, a simulation flight data collection environment based on MATLAB/Simulink and a tool for safety performance analysis were implemented. Test flight and analysis were conducted in the implemented simulation environment in this paper. Finally, this study shows the environment was verified by confirming that it was performed normally.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.5
• /
• pp.450-457
• /
• 2004

In this research, the automatic synthesis of knowledge models is proposed. which are the basis of the methods using qualitative models adapted widely in fault diagnosis and hazard evaluation of chemical processes. To provide an easy and fast way to construct accurate causal model of the target process, the Role-Behavior modeling method is developed to represent the knowledge of modularized process units. In this modeling method, Fault-Behavior model and Structure-Role model present the relationship of the internal behaviors and faults in the process units and the relationship between process units respectively. Through the multiple modeling techniques, the knowledge is separated into what is independent of process and dependent on process to provide the extensibility and portability in model building, and possibility in the automatic synthesis. By taking advantage of the Role-Behavior Model, an algorithm is proposed to synthesize the plant-wide causal model, Fault-Causality Graph (FCG) from specific Fault-Behavior models of the each unit process, which are derived from generic Fault-Behavior models and Structure-Role model. To validate the proposed modeling method and algorithm, a system for building FCG model is developed on G2, an expert system development tool. Case study such as CSTR with recycle using the developed system showed that the proposed method and algorithm were remarkably effective in synthesizing the causal knowledge models for diagnosis of chemical processes.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.12 no.4
• /
• pp.289-297
• /
• 2010

Common practice of Soil Water Assessment Tool (SWAT) model validation is to use a single variable (i.e., streamlfow) to calibrate SWAT model due to the paucity of actual hydrological measurement data in Korea. This approach, however, often causes errors in the simulated results because of numerous sources of uncertainty and complexity of SWAT model. We employed multi-variables (i.e., streamflow, evapotranspiration, and soil moisture), which were measured at mixed forest in Seolmacheon catchment ($8.54\;km^2$), in order to assess the performance and reduce the uncertainties of SWAT model output. Meteorological and surface topographical data of the catchment were obtained as basic input variables and SWAT model was calibrated using daily data of streamflow (Jan. - Dec.), evapotranspiration (Sep. - Dec.), and soil moisture (Jun. - Dec.) collected in 2007. The model performance was assessed by comparing its results with the observation (i.e., streamflow of 2003 to 2008 and evapotranspiration and soil moisture of 2008). When the multi-variable measurements were used to calibrate the SWAT model, the model results showed better agreement with the measurements compared to those using a single variable measurement by showing increases in coefficient of determination ($R^2$) from 0.72 to 0.76 for streamflow, from 0.49 to 0.59 for soil moisture, and from 0.52 to 0.59 for evapotranspiration. The findings highlight the importance of reliable and accurate collective observation data for improving performance of SWAT model and promote its facilitation for estimating more realistic hydrological cycles at catchment scale.