• Journal of Applied Reliability
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• v.16 no.4
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• pp.272-279
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• 2016

Purpose: In order to fulfill the RAMS (Reliability Availability Maintainability and Safety) requirements in Korean railway systems, specific target metrics should be measured and met the requirements when ordering a new system. This paper presents a procedure to predict and demonstrate the availability, maintainability and safety of subway elevators, escalators and PSD (platform screen doors) systems. Methods: The system manufacturer predicts availability and maintainability with lab and field tested data. After installation, availability and maintainability are demonstrated based on the actual operational data. The data was collected from the FRACAS (Failure Report and Corrective Action System). Results: Methods and process of assessing and analyzing the availability, maintainability and safety are presented for elevating services and PSD systems. The data obtained through the actual operation of the equipment is analyzed and maintained to predict the RAMS based on the component and system level failure data acquired. Conclusion: This study presented an application using IEC 62278 and operational data which can be used in the design and development stage to achieve the RAMS target value of the subway elevators, escalators and PSD systems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.2
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• pp.27-37
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• 2022

In this paper, we presents a Multiple User Multiple Input Multiple Output (MU-MIMO) test-bed system for Time Division Duplex (TDD) Long Term Evolution-Advanced (LTE-A). Using two parameters, the condition number of the channel matrix and the path gain, the MU-MIMO system could switch pre-coder to maintain target Bit Error Rate (BER) level. This paper also introduces a calibration procedure for compensating error of Radio Frequency (RF) paths of the antennas and RF transceivers. From experimental measurements, dynamic pre-coding scheme could maintain target BER, set to 10^-3, with the pre-coder set configured with Zero Forcing (ZF), Tomlinson Harashima Pre-coding (THP), Lattice Reduction (LR). The simplest pre-coder ZF is adopted in stable channel, and when path gain become less than 0.25, LR is adopted. Lastly, when condition number of channel matrix become larger than 7, THP is adopted.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.459-462
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• 2015

Korean construction industry made a huge growth over several decades. However, domestic construction market has shrunk in recent years due to the domestic political environments and global economic crisis. Today, the international construction markets become more important to be investigated, and demands for international construction study have risen. The purpose of this study is to search for measures to compare the potential of Southeast Asian countries' construction markets and select strategic target countries where the Korean construction companies pursue to explore for future investments. The research team investigated a range of selection factors which can represent the construction market condition of each country. These factors included the size of the construction industry, economic growth potential, current relationship with Korea, the level of infrastructure development, political situation, etc. After collecting data, each selection factor was scored by experts' analyses and the total score was given to each country. As a result, the rating identified attractive countries for future investments: Myanmar, Vietnam, and Sri Lanka. For the target countries, analytical methods were used for in-depth market analysis that can provide comprehensive insight and strategic clue for development of short-/mid-/long-term roadmap and action plans. The research findings would be used to support rational decision making of construction investment advancing to the Southeast Asian economic growth.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2266-2273
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• 2024

A machine learning platform is proposed for the diagnosis of a severe accident progression in a nuclear power plant. To predict the key parameters for accident management including lost signals, a long short term memory (LSTM) network is proposed, where multiple accident scenarios are used for training. Training and test data were produced by MELCOR simulation of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident at unit 3. Feature variables were selected among plant parameters, where the importance ranking was determined by a recursive feature elimination technique using RandomForestRegressor. To answer the question of whether a reduced order ML model could predict the complex transient response, we performed a systematic sensitivity study for the choices of target variables, the combination of training and test data, the number of feature variables, and the number of neurons to evaluate the performance of the proposed ML platform. The number of sensitivity cases was chosen to guarantee a 95 % tolerance limit with a 95 % confidence level based on Wilks' formula to quantify the uncertainty of predictions. The results of investigations indicate that the proposed ML platform consistently predicts the target variable. The median and mean predictions were close to the true value.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.4
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• pp.29-38
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• 2011

In this study, neighborhood facility and office building to target two cases were performed BIM process. In the initial design phase of the planning process was conducted for the BIM process modeling, BIM in the design stage while performing the required range and level of the process were studied. Accordingly, from architectural firms to leverage BIM process, the proposed methods, efficient use of the modeling process proposed. Quality management information and input for the modeling and design process should be determined from the initial design and construction, including, for each field should be considered BIM, which require an appropriate range of information, according to these requirements, BIM creation and expansion of the level of information should be clearly defined. Perform the procedure for BIM in the process of communicating with stakeholders is critical. In addition, the input data and output data needed to perform management and to perform at the level obtained BIM design process and the model should be clear.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.92-99
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• 2013

Many automotive components for power generation such as motors and alternators have been widely using ferrite magnets. To ensure a high level of efficiency could be achieved in an alternator, the assembled magnets must be in good enough durability. Recently, some hairline cracks have been found on the magnet produced by manufacturers in Korea. Thus, there is an increasing concern that some of the magnets produced could cause further problems after being assembled in the alternator. Based on the standard alternator test (RS0008 : 2006), this paper has developed an accelerated failure-free test for magnets in alternator to demonstrate that assembled magnets will meet durability objective specified by the manufacturer. This guarantees the target life of the magnet with 90 percent reliability and 90 percent confidence level (R90C90). Temperature and rotation speed were selected as accelerated stress factors.

• Proceedings of the Technology Innovation Conference
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• 2003.06a
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• pp.108-115
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• 2003

Government R&D Project Management in Korea has had considerable difficulties because of the lack of project monitoring systems and insufficient communication. The National Program for Tera-level Nanodevices (TND Program) is a ten-year R&D program for commercialization in the area of nano technology. Collaboration and communication among the various participants such as business companies, universities, and government R&D institutes are key success factors in this R&D program. TND Program office has developed a Web-based project management system. This system consists of mostly four sub-management functions: (1) Milestones management of all R&D projects; (2) DR (Design Review) management as the mechanism for checking the performance against milestones; (3) Project activity management using the WBS (Work Breakdown Structure); (4) Budget management. Additionally, it also has many R&D supporting functions such as technology information bulletin board, community management, and visual summary of project progress and performance. This system is effective for monitoring research project as well as measuring project performance of the overall research program. This Web-based system has become the useful tool of R&D moving target mechanism and effective communication and collaboration tool. System features and adoption process of the system are also suggested.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.9
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• pp.303-320
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• 1998

Today the corporate environment is changing rapidly in a standpoint of politics, economics, society and technology environment. So corporates need a management strategy in another point of view. As a new menagement strategy it is introduced corporate culture. The corporate culture should be built with the core of CI, in order to be adapted to peripheral circumstances of the company. The purpose of this thesis is to contribute to manage the systematic management of corporate image by inquiring into corporate identity. Through the research of the deluxe hotels in seoul it is tried to find hotel CI-concept. As a result, the knowledge level of hotel managers is a little low and considered simply as the modification of basic elements and development of a visual idenification system. The emphasis must be on the coordination and integration to create a desired coroporate image and to communicate this image created for the target audience in a systematic and unified mannr.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.1
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• pp.84-97
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• 2020

This paper aims to develop an optimized inventory management method for safety critical Instrument and Control (I&C) components. In this regard, the paper focuses on estimating the consumption rate of I&C components using demand forecasting methods. The target component for this paper is the Foxboro SPEC-200 controller. This component was chosen because it has highest consumption rate among the safety critical I&C components in Korean OPR-1000 NPPs. Three analytical methods were chosen in order to develop the demand forecasting methods; Poisson, Generalized Linear Model (GLM) and Bootstrapping. The results show that the GLM gives better accuracy than the other analytical methods. This is because the GLM considers the maintenance level of the component by discriminating between corrective and preventive.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.175-190
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• 1997

Organizational change projects such as Business Process Redisign (BPR) have been perceived to incur high risk due to their high management complexity, enterprise-wide impace, and steep project cost. This research intends to reduce such risk by developing a systematic process redesign methods, called Dynamic Process Modeling (DPM) method. DPM integrates the customer-oriented business process modeling technique with computerized visual simulation technique to promote better understanding of the target process and enable performance simulation of the proposed redesign alternatives prior to actual BPR implementations. For the cusstomer-oriented process modeling, we propose Dynamic-Event Process Chain (Dynamic-EPC) extending from the conceptual customer process model, Event-Process Chain (EPC). We compare DPM with four other implementation-level process modeling methods over eight criteria and demonstrate its effectiveness by applying it to the real-world hospital BPR case.