• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.36-41
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• 2008

Cooling tower is an important equipment of the cooling systems for large buildings like factory and department store. Water used for cooling in cooling tower is reused continuously. If the water is polluted, corrosion and scale can happen at equipments and pipes. In order to prevent this problem, it is necessary to control the water quality using chemicals. To control the water quality, an automatic control system is designed, fabricated, and experimented. The control system is based on an imbedded microcontroller. Relays are used for power driving, an LCD and LED for display, and RS485 for remote data acquisition. Monitoring program is also developed for easy man-machine interface and extraction of data stored in the imbedded processor and EEPROM. The control system calculates amounts of chemicals necessary using sensor data and injects the chemicals into the cooling tower on proper time. The developed water quality control system is expected to reduce cost of maintenance and extend the lifetime of the cooling systems with low cost.

• Journal of Information Science Theory and Practice
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• v.2 no.4
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• pp.61-76
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• 2014

The exponential growth of information on the web far exceeds the capacity of present day information retrieval systems and search engines, making information integration on the web difficult. In order to overcome this, semantic web technologies were proposed by the World Wide Web Consortium (W3C) to achieve a higher degree of automation and precision in information retrieval systems. Semantic web, with its promise to deliver machine understanding to the traditional web, has attracted a significant amount of research from academia as well as from industries. Semantic web is an extension of the current web in which data can be shared and reused across the internet. RDF and ontology are two essential components of the semantic web architecture which support a common framework for data storage and representation of data semantics, respectively. Ontologies being the backbone of semantic web applications, it is more relevant to study various approaches in their application, usage, and integration into web services. In this article, an effort has been made to review the research work being undertaken in the area of design and development of ontology supported information systems. This paper also briefly explains the emerging semantic web technologies and standards.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.443-450
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• 2016

The linearization technique for low noise amplifier (LNA) has been implemented in standard $0.18-{\mu}m$ BiCMOS process. The MOS-BJT derivative superposition (MBDS) technique exploits a parallel LC tank in the emitter of bipolar transistor to reduce the second-order non-linear coefficient ($g_{m2}$) which limits the enhancement of linearity performance. Two feedback capacitances are used in parallel with the base-collector and gate-drain capacitances to adjust the phase of third-order non-linear coefficients of bipolar and MOS transistors to improve the linearity characteristics. The MBDS technique is also employed cascode configuration to further reduce the second-order nonlinear coefficient. The proposed LNA exhibits gain of 9.3 dB and noise figure (NF) of 2.3 dB at 2 GHz. The excellent IIP3 of 20 dBm and low-power power consumption of 5.14 mW at the power supply of 1 V are achieved. The input return loss ($S_{11}$) and output return loss ($S_{22}$) are kept below - 10 dB and -15 dB, respectively. The reverse isolation ($S_{12}$) is better than -50 dB.

• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.147-156
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• 2022

Ontologies are knowledge containers in which information about a specified domain can be shared and reused. An event happens within a specific time and place and in which some actors engage and show specific action features. The fact is that several ontology models are based on events called Event-Based Models, where the event is an individual entity or concept connected with other entities to describe the underlying ontology because the event can be composed of spatiotemporal extents. However, current event-based ontologies are inadequate to bridge the gap between spatiotemporal extents and participants to describe a specific domain event. This paper reviews, describes and compares the existing event-based ontologies. The paper compares various ways of representing the events and how they have been modelled, constructed, and integrated with the ontologies. The primary criterion for comparison is based on the events' ability to represent spatial and temporal extent and the participants in the event.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.773-786
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• 2017

The current study aims to analyze the process of fabric production planning in Dongdaemun Market, which is a successful model case industrial integration in South Korea. We followed the changes in perception among fabric experts, regarding their recognition of fashion trends, and the following planning and process of fabric production. We used the purpose sampling method to select participants for interview in the Dongdaemun Market, then we carried out one-to-one interviews. Our analysis reveals 4 points of importance. First, the fabric planning stage either employed the trend book swatch, or simply reused the model fabrics already available. Even though the experts felt the need to accept the latest fashion trends, very few considered the trends as positive influences in fabric planning. Whereas trend was a key element in identifying the flow of the fashion industry, there were obstacles in carrying out the study. Second, experts frequently participated in domestic fabric seminars, but not in textile exhibitions. Third, domestic and overseas market research has been performed typically at department stores, and typically at Japan. Fourth, the influx of Chinese fabrics has both positive and negative influences, such as low price, and low reliability. In conclusion, experts were less amenable to accepting the latest fashion trends. pre-requisites in real life to meet the use of the current trend of each company. More studies on the Dongdaemun Market from perspectives of practitioners are warranted.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.158-165
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• 2013

In this paper, a new circuit topology of an ultra-wideband (UWB) 3.1-10.6GHz CMOS low noise amplifier is presented. The proposed UWB low noise amplifier is designed utilizing RC feedback and LC filter networks which can provide good input impedance matching. In this design, the current-reused topology is adopted to reduce the power consumption and the inductor-peaking technique is applied for the purpose of bandwidth extension. The performance results of this UWB low noise amplifier simulated in $0.18-{\mu}m$ CMOS process technology exhibit a power gain of 14-14.9dB, an input matching of better than -10.8dB, gain flatness of 0.9dB, and a noise figure of 2.7-3.3dB in the frequency range of 3.1-10.6GHz. In addition, the input IP3 is -5dBm and the power consumption is 12.5mW.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.285-294
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• 2012

Current urban stream conditions and their restoration projects were investigated by surveying the urban stream management experts in 29 cities with high population density (more than 1,000person/$km^{2}$). The survey results showed that the ratio of covered urban streams decreased by 1.4% (from 14% to 12.6%) in the last 5 years through steady river restoration projects promoted by governments. Nonetheless, 36.3% of 369 urban streams surveyed still report stream depletion problems; therefore, more efforts to alleviate the problems caused by distorted water circulation of urban streams are still necessary. Water depletion in many local urban streams, unlike national rivers, is accelerated due to negligence in stream management, budget shortage, and other reasons. To prevent stream depletion, the use of reclaimed water is suggested as one of the prevention plans. When available amounts of reused sewage are estimated through actual available nationwide sewage discharges of each watershed and instream flow of stream, annual instream flow supply of 780 million $m^{3}$ is expected; 4.8% reduction in the pollution load of public sewer treatment facilities is expected; and the creation of new value through water reuse service is expected. Thus, it is important for the reviews of feasibility and alternatives of water reuse projects for flow augmentation to consider not only investment budget reductions, but also environmental aspects. Also it is necessary to provide the financial support of unified government with strict water quality management policy.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.148-165
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• 2012

Applying maintenance simulation using virtual mockup in product design phase enables maintainability test before prototyping physical products, and it is expected to reduce product development costs. The simulation results can be reused as contents of service manuals and RAM (Reliability, Availability, Maintainability) analysis data. Maintenance simulation should provide realistic representation of physical property of virtual product, assembly relation between parts and manipulation process to verify feasibility of product design. The simulation system should be extended to collaborative virtual environment to perform collaborative maintenance procedures. In this paper, the three layered system architecture and the physics based collaborative interaction technique are proposed to extend current maintenance simulation into collaborative virtual environment. The proposed system was implemented as ViMMS (Virtual Mockup Maintenance Simulation system), and compared with case study results of VADE (Virtual Assembly Design Environment). As a result, the ViMMS encompassed broader range of maintenance tasks by using physics based collaborative interaction technique.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.43-48
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• 2020

It is considered that most of reusable pipe supports, which are used as formwork support posting at construction sites, do not meet the performance standard. Due to the use of reusable pipe supports that do not meet such performance standard the potential risk of collapse accident is increasing. Therefore, this study identifies the status of compliance with performance standard, and presents the requirements for improving quality control to prevent the collapse of pipe supports reused at the construction site. First, if the female thread of the product with no clearance and new support pin with the diameter of 12mm are replaced at the same time for use, it is considered that the performance will be improved. Second, as the quality performance during use can be improved in the case of larger thickness of inner diameter compared to the case of larger thickness of outer diameter, it is necessary to increase the inner pipe thickness greatly than the current thickness. Based on the results of this study, it is expected that the performance the reusable pipe support (V4) can be improved, if the diameter of the support pin is 12mm, the female thread has a small clearance, and the inner tube thickness is 2.3 ~ 2.7mm. In addition, it is considered that other performance improvement factors included in the study results could be used as important data for improving the performance of reusable pipe support.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.290-295
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• 2015

The purpose of this study is to separate nitrocellulose from 175 mm ammunition propellant by environmentally responsible recovery method. Recovery of nitrocellulose from obsolete ammunition is much more desirable than destruction since it can be reused in the several purpose. In spite of durable demilitarization of obsolete ammunition, the current holding amount of obsolete ammunition is gradually increasing and accumulated. The existing demilitarization methods, such as incineration and priming are strictly restricted for the noise, dust, oscillation and air and soil pollution. This study is focused on the separation of nitrocellulose by environmentally responsible recovery method by the solubility difference of nitrocellulose in nonpolar solvent. The purity of an extracted nitrocellulose was analysed by IR and TLC method and was clarified as very high.