• Corrosion Science and Technology
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• v.3 no.4
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• pp.166-171
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• 2004

Recent developments in Bridge Management Systems (BMS) and in Life-Cycle Cost (LCC) of bridges, have raised the need for evaluation procedure of future condition (Deterioration) of a bridge. Predicting future deterioration is not an easy task due to limited past data to extrapolate from and also due to difficulty in measuring actual deterioration such as section loss of steel on an actual steel bridge. Also, increase in live load and reduction of resistance are random variables, thus a probabilistic approach should be adopted for determining the future deterioration. Due to difficulties in evaluation of future deterioration on steel bridges, accepting uncertainties within a reasonable error, a deterministic procedure using bridge condition rating can be a useful tool for projection of future condition of bridges to identify repair and maintenance needs. The object of this paper is to determine applicability of evaluating deterioration of steel bridge components based on Bridge condition ratings. Bridge condition ratings of bridge components show wide variation for bridges of same age and does not directly correlate well with the age of the bridge and/or deterioration of the bridge. High uncertainty can be reduced by breaking down the rating and by sensitivity analysis. From refined condition rating data, generalized deterioration profile of structures based on age can be derived. Examples are shown for sample bridges in USA. Approximately, 3,000 short to medium span steel bridges were listed in the inventory database. Results show wide variation of rating factors but by subdividing the Bridge condition ratings for various categories general deterioration profiles of steel bridges can be determined.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.2
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• pp.45-56
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• 2009

The use of national R&D reports becomes a difficult task due to the different level of service being provided and the different way used for its construction by the institute in management. One-stop service of its contents is impossible and there is a lack of specialized service such as a system to satisfy the various needs of the researchers. This study analyzes the laws related to the national R&D reports and the evaluation system of the R&D outputs for the design and construction of the DB and system for the management of the national R&D reports. We also perform an analysis of the economic effect of the system.

• ETRI Journal
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• v.32 no.3
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• pp.395-405
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• 2010

A novel multiclassifier system (MCS) strategy is proposed and applied to a text-dependent speaker verification task. The presented scheme optimizes the linear combination of classifiers on an on-line basis. In contrast to ordinary MCS approaches, neither a priori distributions nor pre-tuned parameters are required. The idea is to improve the most accurate classifier by making use of the incremental information provided by the second classifier. The on-line multiclassifier optimization approach is applicable to any pattern recognition problem. The proposed method needs neither a priori distributions nor pre-estimated weights, and does not make use of any consideration about training/testing matching conditions. Results with Yoho database show that the presented approach can lead to reductions in equal error rate as high as 28%, when compared with the most accurate classifier, and 11% against a standard method for the optimization of linear combination of classifiers.

• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.204-213
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• 2008

In this paper, we present the practical application of an Unscented Kalman Filter (UKF) for an Indoor Mobile Localization System using ultrasonic sensors. It is true that many kinds of localization techniques have been researched for several years in order to contribute to the realization of a ubiquitous system; particularly, such a ubiquitous system needs a high degree of accuracy to be practical and efficient. Unfortunately, a number of localization systems for indoor space do not have sufficient accuracy to establish any special task such as precise position control of a moving target even though they require comparatively high developmental cost. Therefore, we developed an Indoor Mobile Localization System having high localization performance; specifically, the Unscented Kalman Filter is applied for improving the localization accuracy. In addition, we also present the additive filter named 'Pre-filtering' to compensate the performance of the estimation algorithm. Pre-filtering has been developed to overcome negative effects from unexpected external noise so that localization through the Unscented Kalman Filter has come to be stable. Moreover, we tried to demonstrate the performance comparison of the Unscented Kalman Filter and another estimation algorithm, such as the Unscented Particle Filter (UPF), through simulation for our system.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.2
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• pp.158-165
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• 2013

This paper presents design and workspace analysis of a Korean home service robot. The robot is designed with specific needs of floor-task applications suitable for Korean life style. Shoulder and waist of the robot are adjusted by sliding mechanism to increase the workspace of the robot arms. Manipulators are designed and built and their workspaces are analyzed. Experimental studies of the robot for cleaning the floor are conducted.

• Convergence Security Journal
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• v.13 no.6
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• pp.3-9
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• 2013

With the rapidly changing information communication environment and development of technologies, the informati on networks are evolved from traditional fixed form to an active variable network that flexible large variety of data can be transferred. To reflect the needs of users, the next generation using DWDM (Dense Wavelength Division M ultiplexing) transmission system and OXC (Optical Cross Connect) form a dynamic network. After that GMPLS (Ge neralized Multi-Protocol Label Switching) can be introduced to dynamically manage and control the Reconfigurable Optical Add-drop Multiplexer (ROADM)/Photonic Cross Connect (PXC) based network. This paper propose a softw are architecture of Path Computation Element (PCE) protocol that has proposed by Internet Engineering Task Force (IETF) to path computation. The functional blocks and Application Programming Interface (API) of the PCE protoco l implementation are also presented.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.1-14
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• 2014

Objective: The purpose of this study is to select the methodology for SMR HRA which has characteristics that are different from existing nuclear power plants and digital-based plants. Background: We must assure safety to preoccupy export of technology to developing countries or countries interested in nuclear application. And we can be an advanced country in nuclear technology by securing original technology in the field of SMR such as SMART. Method: THERP, which is the most representative HRA methodology among all, and RARA, which is the latest HRA methodology. This study compared and evaluated THERP and RARA. Results: As a result of applying THERP and RARA methodologies which are based on LOCA EOG task analysis result, this research concluded that RARA has higher personal errors than THERP. Conclusion: This study needs validation for LOCA, emergency operations, normal and abnormal scenarios since HRA methodology was only focused on LOCA scenario. Application: The results of this study can apply as base line data when designing MMIS, which is the main control room of SMART, and when building a simulator.

• Journal of the Ergonomics Society of Korea
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• v.32 no.3
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• pp.273-278
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• 2013

Objective: This study aims to analyze and evaluate fatigue in upper trapezius muscles of adults when inputting text on a smart phone, thereby examining the risk of cumulative trauma disorders in the musculoskeletal system of the upper extremity. Method: Forty-five healthy adults were divided equally into three groups: a smartphone group, a notebook group, and a desktop group. A surface electromyogram was placed on the upper trapezius muscle of each participant, after which they inputted text for ten minutes within an ergonomic setting; their side posture was recorded on video and analyzed. Results: The spectral edge frequency values for the smartphone group, as recorded from the upper right trapezius muscles on the surface electromyogram, showed a significant decrease(p<.05). Regarding the RULA, all three groups had results indicating "action level 2". Conclusion: All three groups had results indicating "action level 2" according to the RULA, which means that additional research on the posture of the participants while performing tasks is necessary, and their posture needs to be corrected. In particular, the smartphone group has the highest levels of fatigue in the upper trapezius muscles, suggesting that the task of inputting text on a smartphone is a high risk for causing cumulative trauma disorders.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.73-76
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• 2006

Pilots and navigators have through history used everything available to support them in the execution of their task. From the simple sounding means (for instance a stick or a line with a heavy object tied to it) to the advanced electronic support systems that are available today. This means that apart from the more traditional side of his set of tasks the influence of modern technology is felt. In general it concerns such diverse and complex subjects that it requires the pilot to remain up to date with regard to the most modern techniques. In a sense this also concurs with the change form a provider of (local) knowledge to that of a manager of a high risk operation. More information flows can reach the pilot on the place where he executes his profession. With marginal scope the pilot has to translate such information to the situation in which he finds himself in order to give a balanced advice. Knowledge of the surroundings, variable circumstances in his specific area but also language and culture play a crucial role. This paper touches on the history of pilot support systems and examines the developments of pilot support systems in the present day operating environment and addresses the implications. These range from the historic basic needs for pilot information to the present and future possibilities, supporting the pilot to make the most precise assessment at each operational stage to continually execute a safe journey in and out of port.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.50-51
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• 2007

과거 단일 회사로 구성된 전력산업 체제하에서의 신뢰도에 대한 인식과 중요성들이 전력시장과 경쟁이 도입된 다각화된 이해 주체들 이 존재하는 현행의 국내 전력산업 구조에서는 서로 다른 양상을 띄고 변화하고 있다. 전원 및 송?변전 시설계획에서부터 계통운영 계획 및 실시간 급전에 이르기까지 연속선상의 계통운영 업무에 있어 전력공급의 안정성 확보와 더불어 보다 합리적이고 효율적인 또는 경제적인 계획과 운영에 대한 요구(Needs)가 기존의 결정론적인 신뢰도 평가의 다각적 접근 즉, 확률론적인 신뢰도평가 기법을 개발하게 하였으며, 이에 미국 전력중앙연구소(EPRI)의 PRA(Probabilistic Reliability Assessment) S/W를 도입하여 실제 계통운영의 단위업무와 접목하여 리스크를 고려한 계통안전도평가 구현의 잠재적 가능성과 극복해야 할 한계를 파악하였다.