• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1559-1565
• /
• 2004

Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(tain performance simulator), PES (parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

• Proceedings of the Safety Management and Science Conference
• /
• 2004.11a
• /
• pp.197-203
• /
• 2004

Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(lain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.272-279
• /
• 2003

There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. All of these is intended to increase transport capacity by improving the line capacity, So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. Korea Railroad Research Institute(KRRI) proposed a new line capacity estimation system based on the probability simulation method. In this research. we perform analysis of line capacity for the railway improvement alternatives, and to represent the results.

• Steel and Composite Structures
• /
• v.22 no.6
• /
• pp.1391-1415
• /
• 2016

Limit load of pressure bearing structures was reviewed in this article. By means of the finite element analysis, limit load of pressurized cylinder with nozzle was taken as an example. Stress classification method and Elastic-plastic finite element analysis combining with limit load determination methods were used to determine limit load of cylinder with nozzle. Comparison of limit load determined by different methods, the results indicated that limit load determined by linearization method was the smallest. Limit load determined by twice elastic slope criterion was the nearest than experimental results. Elastic-plastic finite element analysis had comparably computational precision, but required time consuming. And then the requirements of computer processing and storage capacity by power system became higher and higher. Most of criteria for limit load estimation included any human factors based on a certain substantive characteristics of experimental results. The reasonable criterion should be objective and operational.

• Journal of IKEEE
• /
• v.22 no.4
• /
• pp.999-1005
• /
• 2018

This paper proposed a search-based high resolution frequency estimation method in power systme. The proposed frequency estimation method adopts a slope-based adaptive search as a base of adaptive estimation structure. The architectural and operational parameters in this adaptive algorithm are changed using the information from context layer analysis of the signals including a localized full-search of spectral peak. The convergence rate of the proposed algorithm becomes much faster than those of other conventional slope-based adaptive algorithms by effectively reducing search range with the application of the localized full-search of spectrum peak. The improvements in accuracy and convergence rate of the proposed algorithm are confirmed through the performance comparison with other representative frequency estimation methods, such as, DFT(discrete Fourier transform) method, ECKF(extended complex Kalman filter), and MV(minimum variable) method.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.2
• /
• pp.28-36
• /
• 2009

Many researches have been done to define the physical parameters for the wave generation and transformation over a coastal region. However, most of these have been limited to the application of particular conditions, as they are generally too empirical. To yield more reasonable wave estimation using a spectral wave model, it is important to understand how they work for the wave estimation. This study involved a comprehensive sensitivity test against the spectral resolution and the physical source/sink terms of the spectral wave model using SWAN and TOMAWAC, which have the same physical background with several different empirical/theoretical formulations. The tests were conducted for the East Anglian coast, UK, which is characterized by a complex bathymetry due to several shoals and offshore sandbanks. For the quantitative and qualitative evaluation of the models' performance with different input conditions, the wave elements and spectrums predicted at representative sites the East Anglia coast were compared/analyzed. The spectral resolution had no significant effect on the model results, but the lowest resolution on the frequency and direction induced underestimations of the wave height and period. The bottom friction and depth-induced breaking terms produced relatively high variations in the wave prediction, depending on which formulation was applied. The terms for the quadruplet and whitecapping had little effect on the wave estimation, whereas the triads tended to predict shorter and higher waves by energy transferring to higher frequencies.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.19 no.4
• /
• pp.526-535
• /
• 2016

In this study, the estimating weight data of eight leading ships of Korea navy were processed by comparing with the final weight data of their incline test results statistically, and are analyzed as follows; The maximum criteria of the weight margins of Korea naval ship in the preliminary and detailed design phases seem to be appropriate values, but the minimum criteria would be advisable to update more reasonable values. And, the limitation that the acceptable deviation of lightship weight should be 10 % of the lightship weight on a naval ship's ROC(Required Operational Capabilities) is recommended to be prohibited, because it comes from the weight estimation which has considerable uncertainty and it may also drop off design flexibility. Finally, the SWBS(Ship Work Breakdown System) groups which have larger deviation values in the estimating weight of naval ships are necessary to improve their accuracies, and to upgrade their weight database continuously.

• International Journal of Highway Engineering
• /
• v.16 no.5
• /
• pp.173-182
• /
• 2014

PURPOSES : The purpose of the study is to a) explore the operating speed of trucks on rural highways affected by road geometry, and thereby b) develop a predictive model for the operating speed of trucks on rural highways. METHODS : Considering that most of the existing studies have focused on cars, the current study aimed to predict the operating speed of trucks by conducting linear regression analysis on the speed data of trucks operating on the linear-curved-linear portions of the road as a single set. RESULTS : The operating speed in the plane curve portion increased with the length of the curve, and decreased with a lower vertical grade and a smaller curve radius. In the straight plane portion, the operating speed increased with a larger curve radius(upstream), and decreased with an increase in the change of the vertical grade, depending on the length of the vertical curve. CONCLUSIONS : This study developed estimation models of truck for operational speed and evaluated the degree of safety for horizontal and vertical alignments simultaneous. In order to represent whole area of the rural highway, the models should be ew-analyzed with vast data related with road alignment factor in the near future.

• Journal of Information Technology Services
• /
• v.16 no.2
• /
• pp.45-60
• /
• 2017

The study suggests a contract model of application operation through case study of A bank's IT outsourcing application contract based on workload. The IT outsourcing order form has a problem in that the scope of work is ambiguous due to the integration of operation and maintenance. In this study, application operation and maintenance were separated by referring to application operation history provided in ISO/IEC15504-5 standard. The scope of the IT outsourcing service was clarified by organizing the definition and detail activities of the application operation business. Application operation contract method has generally applied estimation method by the number of input manpower and period by agreement between buyer and client. As there is no activity to calculate the number of input manpower based on the operational work history and based on the standard workload per activity. In this case is not guaranteed due to the simple agreement between the contractors. In this paper, we propose an application operating cost estimation model that measures the size of the operating software using function point analysis that is the basis of application operation tasks. In order to verify the validity of the application operation cost model, we verified the correlation between the application size and the labor cost through regression analysis using SPSS.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.17 no.1
• /
• pp.25-34
• /
• 2021

Availability is one of the important factor for developing weapon system, because it indicates the mission capability and sustainable life cycle management of weapon system. Recently, as weapon system becomes more advanced and more complex, availability estimation becomes more important to reduce the life cycle cost of weapon system. Modeling and simulation(M&S) is useful method to describe the availability of complex weapon system applying operational environment and maintenance plan. Especially agent based model(ABM) has the strength to describe interactions between agents and environments in complex system. Therefore, this paper presents the availability estimation of weapon system using agent based model. The sample data of part list and reliability analysis is applied to build availability estimation model. User agent and mechanic agent are developed to illustrate the behavior of operation and maintenance using formal specification. Storage reliability is applied to describe failure of each parts. The experimental result shows that this model is quite useful to estimate availability of weapon system. This model may estimate more reasonable availability, if full scale data of weapon system and real field data of operation is provided.