• Journal of Power Electronics
• /
• v.15 no.5
• /
• pp.1149-1157
• /
• 2015

As a key part in the wind turbine system, the power electronic converter is proven to have high failure rates. At the same time, the failure of the wind power converter is becoming more unacceptable because of the quick growth in capacity, remote locations to reach, and strong impact to the power grid. As a result, the correct assessment of reliable performance for power electronics is a crucial and emerging need; the assessment is essential for design improvement, as well as for the extension of converter lifetime and reduction of energy cost. Unfortunately, there still exists a lack of suitable physic-of-failure based evaluation tools for a reliability assessment in power electronics. In this paper, an advanced tool structure which can acquire various reliability metrics of wind power converter is proposed. The tool is based on failure mechanisms in critical components of the system and mission profiles in wind turbines. Potential methodologies, challenges, and technology trends involved in this tool structure are also discussed. Finally, a simplified version of the tool is demonstrated on a wind power converter based on Double Fed Induction Generator system. With the proposed tool structure, more detailed information of reliability performances in a wind power converter can be obtained before the converter can actually fail in the field and many potential research topics can also be initiated.

• Korean Institute of Interior Design Journal
• /
• v.20 no.3
• /
• pp.242-248
• /
• 2011

According to a study on the accident patterns of older people in 2006 by Korea Consumer Agency (CISS), the number of accidents of the elderly at home reached 486, and the figure has increased every year. As Korea is about to enter into the aged society, it is important to investigate the factors that cause an accident in the welfare facilities for the aged and establish the barrier-free construction standards. The accident influence factors include facility environmental, physical functional, socio demographic and socio psychological factors. In terms of the verification tools, there are Facility Evaluation Index, FIM, MMSE-K and General Feature. In terms of analysis method, in addition, there are real number, percentage, t-test, ANOVA and logistic regression. In conclusion, this paper attempts to reveal correlations among the accident influence factors using the Facility Evaluation Standards (115 items in total) for facility environmental factor, FIM (3 items) for physical functional factor, MMSE-K (6 items) for socio psychological factor and questionnaire (5 items) for socio demographic factor.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1630-1641
• /
• 2010

LCC can be defined as "the sum of present values of investment costs, capital costs, installation costs, energy costs, operating costs, maintenance costs, and disposal costs over the life-time of the project, product, or measure." LCCA involves estimating the costs and timing associated with each alternative over a selected analysis period and conversion of those costs to economically comparable values considering the time-value of money. The several Excel-Based LCC tools found on the internet are described in this paper. Also, This paper performed an analysis of the existing LCC commercial tools, assessing various aspects of each program. The goal was to evaluate the best features of each tool and to identify the requirements for LCC evaluation of Urban Transit Vehicle. The LCC tools are developed to address problems in many different areas and a tool developed and structured for one area cannot generally be used in another area. No general LCC tool exists and if one is needed for Urban Transit Vehicle it has to be developed by the project. Since a full LCC can be very complex it is likely that this Excel-Based LCC tool should be a small and simple tool for quick cost estimates. This paper presents a LCC tool consisting of eight excel sheets, which are "Project", "CBS", "PBS", "PM", "CM", "Others", "LCC Result" and "Diagram".

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.9 no.2
• /
• pp.52-65
• /
• 1999

This study was performed to evaluate the hand-arm vibration of the steel processing factory workers. Measurement, evaluation and as sessment were based on the International Standard(ISO 5349). The frequency weighted accelerations of the various hand-held tools and total exposure time were measured to assess the periods for the white finger symptom to occur. As a result, it was found that the air angle grinder and the air baby grinder are more harmful than other hand-held tools. It was also found that using various vibratory tools together is more harmful than using a single tool.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.10
• /
• pp.7-11
• /
• 2009

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.17 no.30
• /
• pp.167-175
• /
• 1994

Generally, queueing networks, networks, chains and simulation techniques are among the most widely used evaluation tools to study computer systems, manufacturing systems etc. But, these tools have some assumptions and difficulties. So, this thesis presents a method for manufacturing system using Petri nets. Petri nets are a graphical and mathmatical modeling tool and are promising tool for describing and studying systems that are characterized as being concurrent asychronous, dynamic, distributed and parrallel. It designs Petri net model for processing time of manufacturing system And it applied to a job shop system composed of 8 machines and 4 different job types.

• Proceedings of the KSR Conference
• /
• 1999.11a
• /
• pp.495-502
• /
• 1999

Typical analytical tools in noise level estimation are using BEM and Ray Acoustics for acoustic field.0 this paper, application of both approaches have been examined for the prediction on the exterior surface of railway vehicles. Advantages and disadvantages of the tool have been also evaluated. The result shows that sound understanding of the analytical tools for noise evaluation is necessary.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.3
• /
• pp.403-410
• /
• 2020

Continuous industrial development has led to a better quality of life for everyone, even further accelerating industrial growth. Industrial development, however, has also caused environmental degradation, which is posing a serious threat to humanity. It has also encouraged the indiscriminate use of limited resources, causing resource depletion. Efficient resource management based on resource circulation is critical to saving resources. Resource circulation methods are as follows: reducing the use of resources in the manufacturing process, recycling used or reprocessed products and reusing used resources without being reprocessed, remanufacturing with end-of-life products with disassembled parts. Furthermore, remanufacturing process including cleaning, inspection, repairing, and reassembling facilitate performance level as well as new typical products. It is noteworthy that the remanufacturing of machine tools can significantly save resources because their structural parts are substantially large in size. Machine tools have served as a foundation for the manufacturing industry, which has driven Korea's industrial development. Nevertheless, a few research has been reported for remanufacturing technology with used machine tools. Relevant research of developing a remanufacturing process chart and method is prerequisite for saving the resource and environments.

• Anxiety and mood
• /
• v.12 no.2
• /
• pp.86-96
• /
• 2016

Paraphilia and paraphilic disorder is one of mental disorders making it difficult to assess and treat. Recently, a number of methods for assessing the paraphilia are being developed gradually outside south Korea. And the reliability and validity of various assessment tools are being reported. The standardization of the assessments and questionnaires was not made yet. For assessment of paraphilia that has been reported from abroad, the author comprehensively organized clinical interview, physical examination, psycho-physiological methods, self-reporting scale of sexual thoughts, fantasies and attitudes and multiple self-reporting scale of sexual interests and described the clinical significance of the assessment tools. The national standardization of both self-reported questionnaire and physical evaluations is expected to be completed later.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.07a
• /
• pp.799-801
• /
• 2005

There have been many streaming servers that provide a large number of contents for a user's preference. General purpose streaming sewer makes use of a RTSP protocol for streaming controls such as message passing with client players. To date, there has been minimal research regarding streaming server's performance test tools. For measuring streaming server's performance, performance evaluation technique is needed and also achieved by RTSP based controls, a server's performance result and its miscellaneous test tools such the PseudoPlayer for pumping data to a specified port and the PseudoMonitor for gathering information. In this paper, We implement a test toolkit for evaluating a streaming server's performance and show the case of its application