• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.703-712
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• 2017

The railway system is an interface industry that can be safely operated by organically operating the lines, vehicles, controls, etc. Various data are generated in the operation and maintenance activities of the railway system. These data are utilized in cooperation with safety and maintenance activities in each field, but amount of data is insufficient for data analysis of safety management due to relevant data being produced without any synchronous criteria such as time or space. In particular, reference data such as location and time of failure data for each field are set to different criteria according to the work characteristics in each field. So, it is not easy to analyze data integrally based on location and time. Therefore, mapping of reference data can be required for integrated analysis of data defined in different formats. By selecting data mapping tools and verifying the results of safety relevant data with the same criteria, the purpose of this paper is to enable integrated analysis of railway safety management data occurring in different fields based on location and time.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.90-96
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• 2008

Recently, various recording technologies are studied for optical data storage. After standardization of BD (Blu-ray Disc) and HD-DVD (High-Definition Digital Versatile Disc), the industry is looking for a suitable technology for next generation optical data storage. Super-RENS (Super-Resolution Near Field Structure) technique, which is capable of compatibility with other systems, is one of next optical data storage. In this paper, we proposed a neural network-based nonlinear equalizer (NNEQ) for Super-RENS discs. To mitigate the nonlinear ISI (Inter-Symbol Interference), we applied NARX (Nonlinear AutoRegressive eXogenous) which is a kind of neural networks. Its validity is tested with the RF signal samples obtained from a Super-RENS disc. The performance of the proposed equalizer is superior to the one without equalization and that of the Limit-EQ in terms of BER (Bit Error Rate).

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.189-200
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• 2012

Many companies have endeavored to build a quality cost management system in order to be more productive business organization. This study shows the detail procedures of constructing a quality cost management system which is believed to be appropriate for their business system. That is, the method to calculate the quality cost and the linking logic between the quality improvement and its financial impact are explained based on a particular industry case. In this sense, the changes of business performance measures such as market share, customer satisfaction, etc. were analyzed in the longitudinal perspective for the consecutive 4 years (2003~2006). As the quantitative results of this study, the improvement activities based on the quality cost management system resulted in the 32% reduction of quality cost and the 121% increase of business profit, compared 2005 with 2006. In the qualitative perspective, the successive practice of quality cost reduction and the job information sharing in business unit were obtained by providing the best practices and bench-marking cases. Finally, the customer satisfaction has increased so that the customer-friendly management system has been accomplished. With these efforts, the 3.4% increase of the market share and the 3% increase of the customer satisfaction were obtained in 2005. As the future study, the current study can be extended to the concept of COPQ (cost of poor quality) which focuses on the hidden quality cost of the whole business activities. Such extension of analysis will help us understand the wider role of a quality cost management system in the business.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.331-339
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• 2013

This study highlights the theme of human error emerging as a critical issue in the railroad industry, conducting exploratory research on the effects of health, cognition, and safety climates on safety behavior and accidents using an empirical method. The statistical results based on questionnaires received from 204 train drivers indicate that psychological fatigue, cognitive failure, and internal locus of control as individual variables and CEO philosophy and behavior of immediate boss as organizational variables have significant relationships with safety behavior, while cognitive failure, CEO philosophy, behavior of immediate boss, and education were found to be significant variables with respect to accidents. Furthermore, unsafe behavior such as mistakes and violations showed negative effects on near misses and responsibility accidents, respectively. Based on these results, effective alternatives and countermeasures needed to mitigate human error were posited.

• Journal of KIBIM
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• v.5 no.4
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• pp.53-62
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• 2015

Korea has been at the forefront of green growth initiatives. In 2008, the government declared the new vision toward 'low-carbon society and green growth'. The government subsidies and Feed-in Tariff (FIT) increased domestic usage of solar power by supplying photovoltaic housing and photovoltaic generation systems. Since 2000, solar power industry has been the world's fastest growing source with the annual growth rate of 52.5%. Especially, BIPV(Building Integrated Photovoltaic) systems are capturing a growing portion of the renewable energy market due to several reasons. BIPV consists of photovoltaic cells and modules integrated into the building envelope such as a roof or facades. By avoiding the cost of conventional materials, the incremental cost of photovoltaics is reduced and its life-cycle cost is improved. When it comes to atypical building, numerous problems occur because PV modules are flat, stationary, and have its orientation determined by building surface. However, previous studies mainly focused on improving installations of solar PV technologies on ground and rooftop photovoltaic array and developing prediction model to estimate the amount of produced electricity. Consequently, this paper discusses the problem during a planning and design stage of BIPV systems and suggests the method to select optimal design of the systems by applying the national strategy and economic policies. Furthermore, the paper aims to develop BIM tool based on the engineering knowledge from experts in order for non-specialists to design photovoltaic generation systems easily.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.38-44
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• 2008

Internet Data Centers (IDCs), which are resulted by the rapid progress of Information Technology industry, consist of high-density digital loads with internet server systems. Introduction of DC distribution system may simplify the conventional electric power conversion system, and may result in the improvement of electric power efficiency. However, this conjecture has never been tested under Korean IDC environment. In this study, electric power efficiency of DC distribution system from KT Namsuwon IDC is contrasted with that of conventional AC distribution system from KT Bundang IDC. DC 48[V] based distribution system showed 13.2[%] higher efficiency than the conventional AC based distribution system. The further analysis with the assumption of DC 380[V] suggests efficiency improvement over 25[%] can be achieved.

• Proceedings of the KIEE Conference
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• summer
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• pp.1489-1491
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• 2004

A guard lamp system has been installed at the PV positive center, located at Gwangju in Korea. Digital environment that is represented to internet is displacing business way of industry and business achievement way with the fast speed being giving great change on life whole, improve existence business process utilizing internet and Web connection technology, information superhighway to tradition industrialist manufacture and e-transformation's propulsion that wish to maximize productivity and administration efficiency is spread vigorously. In this paper, we wish to accomplish generation equipment's heighten stability and believability through remote monitoring and control of guard lamp system. This paper describes the design of the monitoring system for the sensing data and indirect controlling of the guard lamp system. Most of the conventional monitoring systems depend on the special hardware and software. The essential design of monitoring system is to provide the convenience for the user and the portability for the system. In order for the system to fulfill its requirements, it was designed using Labview GUI facility based on the Windows 2000 environment of IBM PC compatible and Add-oncard based on the TCP/IP Protocol. Advantage of the monitoring system are a personnel expenses curtailment effect, of the place restriction and unmanned system of the generationplants, etc..

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.73-87
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• 2012

This study was conducted to provide sustainable measures for conservation and management to protect valuable natural/ecological resources, offer differentiated quality assurance services for eco-tourism products, and explore measures for eco-tourism certification/designation systems. To achieve its goals, the study discussed domestic and overseas trends and literatures that concern eco-tourism certification/designation system and investigated case studies that were presently operational. A group of experts and a group of non-experts were surveyed separatedly to investigate the awareness of the national eco-tourism certification/designation system. The results from the investigation indicate that Europe, since the late 1990s to early 2000, has actively introduced a system that establishes and operates a dedicated institution, and European members have created a cooperation framework to formulate international partnerships and develop standardized assessment benchmarks to adhere to the goals of the system, the period for certification was designated from one year to five years, and renewals were granted based on periodic monitoring and reassessment. In Korea, from early 2000, the Ministry of Culture, Sorts and Tourism and other organizations have certified product quality and assessed travel products and national park tour programs. The certification period was established to be set between one and three years, and the vast majority were not reassessed. Upon investigating the results for awareness of national eco-tourism certification/designation system, a high number of respondents agreed with the need to establish a eco-tourism certification/designation system (90% of respondents), and the respondents cited eco-tourism quality assurance, conservation of value, means to maintain established institutions, and environmental education and information as reasons for needing a certification/designation system. In Korea, a certification/designation system for the eco-tourism industry is presently in operation, but the system regulates target institutions based on their characteristics. Therefore, this study proposes its suggestions via various categories, including designated institutions, designated purpose, designated subjects, designated organization, laws, regulations, and incentives.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.11
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• pp.635-642
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• 2004

The traditional communication protocols such as TCP/IP are not suitable for PC cluster systems because of their high software processing overhead. To eliminate this overhead, industry leaders have defined the Virtual Interface Architecture (VIA). VIA provides two different data transfer mechanisms, a traditional Send/Receive model and the Remote Direct Memory Access (RDMA) model. RDMA is extremely efficient way to reduce software overhead because it can bypass the OS and use the network interface controller (NIC) directly for communication, also bypass the CPU on the remote host. In this paper, we have implemented VIA-based RDMA mechanism in hardware. Compared to the traditional Send/Receive model, the RDMA mechanism improves latency and bandwidth. Our RDMA mechanism can also communicate without using remote CPU cycles. Our experimental results show a minimum latency of 12.5${\mu}\textrm{s}$ and a maximum bandwidth of 95.5MB/s. As a result, our RDMA mechanism allows PC cluster systems to have a high performance communication method.

• The KIPS Transactions:PartA
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• v.9A no.1
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• pp.1-8
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• 2002

Most of the traditional embedded web server systems have been designed for monitoring and controlling some dedicated equipments. Hence, not only they have no generality and flexibility but also they are too expensive for the lower-cost domestic equipment. To cope with these difficulty, we suggest a lower-cost ${\mu}$-embedded web server model which is suitable for monitoring and controlling the industry or house equipments by using the internet. The suggested model is based on an one-chip ${\mu}$-processor in which the ISP (In-System Programming) function and flash ROM are embedded basically to minimize the cost of H/W and S/W. Also it allows to add an new function dynamically to provide the generality and flexibility. Finally, to evaluate the feasibility of the suggested model, we have manufactured a test-board based on the ATMega103 ${\mu}$-processor and programmed the control program and tested it on the MS Explorer 5.0 environment.