• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.418-422
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• 2005

In this paper, a novel algorithm capable of detecting generic obstacles on a flat surface is proposed. The algorithm fundamentally exploits a distortion phenomena taken place in remapping process of original stereo images to a virtual top-view. Based on the distortion phenomena, we construct stereo polar histograms of edge maps, detect peaks on them, and search for matched peaks on both histograms using a Dynamic Programming (DP). Eventually, the searched corresponding peaks lead to estimate obstacles' positions. The advantages of the proposed algorithm are that it is not largely affected by an intensity difference between a pair of stereo images and does not depend on the typical stereo matching methodologies. Furthermore, the algorithm identifies the obstacles' positions quite robustly.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1082-1087
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• 2006

Human factors still plays a significant role in railway accidents. The accidents often resulted from multiple causes of hardware failures and human errors. So to ensure the safety of railway operations, human error should be effectively prevented and managed. Among several factors influencing human performance, task load (or task complexity) is well known as a major contributor to human error. In order to reduce the potential of human error, a systematic analysis should be undertaken to evaluate task load and to reduce it by modifying task process and/or education&training. In this paper, we proposed a systematic framework for railway industry to perform task analysis and to evaluate task load, and applied it to KTX operational tasks. According to the application study, we identified 14 generic task types of KTX operation. And also this paper shows the quantitative task load of those generic tasks which were analyzed by NASA-TLX method.

• Structural Engineering and Mechanics
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• v.17 no.2
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• pp.215-244
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• 2004

There is an ever-increasing demand for assessment of earthquake effects on transportation structures, emphasised by the crippling consequences of recent earthquakes hitting developed countries reliant on road transportation. In this work, vulnerability functions for RC bridges are derived analytically using advanced material characterisation, high quality earthquake records and adaptive inelastic dynamic analysis techniques. Four limit states are employed, all based on deformational quantities, in line with recent development of deformation-based seismic assessment. The analytically-derived vulnerability functions are then compared to a data set comprising observational damage data from the Northridge (California 1994) and Hyogo-ken Nanbu (Kobe 1995) earthquakes. The good agreement gives some confidence in the derived formulation that is recommended for use in seismic risk assessment. Furthermore, by varying the dimensions of the prototype bridge used in the study, and the span lengths supported by piers, three more bridges are obtained with different overstrength ratios (ratio of design-to-available base shear). The process of derivation of vulnerability functions is repeated and the ensuing relationships compared. The results point towards the feasibility of deriving scaling factors that may be used to obtain the set of vulnerability functions for a bridge with the knowledge of a 'generic' function and the overstrength ratio. It is demonstrated that this simple procedure gives satisfactory results for the case considered and may be used in the future to facilitate the process of deriving analytical vulnerability functions for classes of bridges once a generic relationship is established.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.539-544
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• 1992

An iterative lear-rung control scheme is newly designed in tile frequency domain. Purposing for batch process control, a generic form of feedback-assisted first-order learning is considered first, and the inverse model-based learning algorithm is derived through convergence analysis in the frequency domain. To enhance the robustness of the proposed scheme, a filtered version is also presented. Performance of the proposed scheme is evaluated through numerical simulations.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.14-18
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• 2013

We introduce a generic method to analyze optical 17reflectance spectra of strongly correlated electron systems including high-temperature superconductors by using an extended Drude model and Allen's approach. We explain the process step by step from reflectance through the optical conductivity and the scattering rate to the bosonic spectral function. Through the process we are able to get important information on the interactions between charge carriers from measured optical conductivity of the strongly correlated electron systems including copper oxide and iron pnitide high temperature superconductors.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.156-173
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• 2004

Business process should support the execution of collaboration process with agility and flexibility through the integration of enterprise inner or outer applications and human resources from the collaborative workflow view. Although the dependency of enterprise activities to the automated system has been increasing, human role is as important as ever. In the workflow modelling this human role is emphasized and the structure to control human error by analysing decision-making itself is needed. Also, through the collaboration of activities agile and effective communication should be constructed, eventually by the combination and coordination of activities to the aimed process the product quality should be improved. This paper classifies human errors can be occurred in collaborative workflow by applying GEMS(Generic Error Modelling System) to control them, and suggests human error control method through hybrid based modelling as well. On this base collaborative workflow modeling tool is designed and implemented. Using this modelling methodology it is possible to workflow modeling could be supported considering human characteristics has a tendency of human error to be controlled.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.1
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• pp.41-50
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• 2017

Systems engineering is being applied to various fields of industry such as national defense, aerospace, transportation, railway, and information technology industries. But in Korea, systems engineering has been selectively applied to government-driven projects such as space rocket development projects and unmanned flight development projects. And systems engineering processes introduced from international systems engineering standards has been directly applied to those projects. Unfortunately, this application method is not recommended as it requires highly experienced systems engineers. From our previous paper, we have proposed that domain specific engineering standards should be developed to be used as references for development of organizational engineering guide, so that more successful engineering performances can be achieved. And in this paper we have proposed a refinement of systems engineering processes from international systems engineering standards as they are bases of domain specific engineering standards.

• Journal of KIISE:Software and Applications
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• v.37 no.6
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• pp.480-485
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• 2010

In the characteristics of CMMI architectures and components, there are many relations among CMMI practices. The organizations can be more efficiently improving their processes if they understand relationship among CMMI practices. However, there are no researches regarding this topic yet. In this paper we analyzed the relationship between Generic Practices and Specific Practices of each process areas in CMMI Maturity Level 2 by using Chi-square test of independence. As a result, we demonstrated that 10 Generic Practices in each process area are related 17 out of 48 Specific Practices (35% relationship). Using this result to improve the organization's processes, we achieved a significant improvement of 36.5% in CMMI appraisal result.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.184-195
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• 1995

A theoretical one-dimensional model for the charging process in stratified thermal storage tanks is established presuming that the fluid ensuing from the tank inlet creates a perfectly mixed, layer above the thermocline. Both the generic and asymptotic closed-form solutions are obtained via the Laplace transformation. The asymptotic solution describes the nature of the charging pertaining to the case of no thermal diffusion, whereas the generic solution is of practical importance to understand the role of operating parameters on the stratification. The present model is validated through comparison with available experimental data, where they agree well with each other within a reasonable limit. An interpretation of the exact solution entails two important features associated with the charging process. The first is that an in-crease in the mixing depth $h_m$ causes a relatively slow temperature rise in the perfectly mixed region, but on the other hand it results in a faster decay of the overall temperature gradient across the thermocline. Next is the predominance of the mixing depth in the presence of the prefectly mixed region. In such a case the effect of the Peclet number is marginal and there-fore the thermal characteristics are solely dependent on the mixing depth paticularly for large $h_m$. The Peclet number affects significantly only for the case without mixing. Variation of the storage efficiency in response to the change in the mass flow rate agrees favorably with the published experimental results, which confirms the utility of the present study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1371-1378
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• 2009

We propose a low-power eFuse one-time programmable (OTP) memory cell based on a logic process. The eFuse OTP memory cell uses separate transistors optimized at program and read mode, and reduces an operation current at read mode by reducing parasitic capacitances existing at both WL and BL. Asynchronous interface, separate I/O, BL SA circuit of digital sensing method are used for a low-power and small-area eFuse OTP memory IP. It is shown by a computer simulation that operation currents at a logic power supply voltage of VDD and at I/O interface power supply voltage of VIO are 349.5${\mu}$A and 3.3${\mu}$A, respectively. The layout size of the designed eFuse OTP memory IP with Dongbu HiTek's 0.18${\mu}$m generic process is 300 ${\times}$557${\mu}m^2$.