• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4721-4726
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• 2010

The performance characteristics of water-chilling heat pump using CO2 for the control of inverter frequency was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter flow type heat exchangers with concentric dual tubes, which are made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2.4m length. The experimental results summarize as the following: for constant inlet temperature of evaporator and gas cooler, as mass flow rate, compression ratio and discharge pressure increases with the inverter frequency. And heating capacity and compressor work increases, but coefficient of performance(COP) decreases with the inverter frequency of compressor. As inlet temperature of secondary fluid in the evaporator increases from $15^{\circ}C$ to $25^{\circ}C$, compression ratio and compressor work decreases, but mass flow rate, heating capacity and COP increases with the inverter frequency of compressor. The above tendency is similar with performance variation with respect to the variation of inverter frequency in the conventional vapor compression refrigeration cycle.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.133-142
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• 2004

The next generation of web applications will need to be larger, more complex, and flexible Agent-oriented systems have great potential for these e-commerce applications. Agents can dynamically discover and compose e-services and mediate interactions. Development of software agents with CBD (Component Based Development) has proved to be successful in increasing speed to market of development Projects, lowering the development cost and providing better qualify. In this thesis, we propose a systemic development process for software agents using component and UML (Unified Modeling Language). We suggest a etA (e-business Agent) CBD reference architecture for layer the related components through identification and classification of general agent and e-business agent. We also propose the ebA-CBD process that is a guideline to consider the best features of existing agent oriented software engineering methodologies, while grounding agent-oriented concepts in the same underlying semantic framework used by UML. We first developed the agent components specification and modeled it with Goal, Role, Interaction, and Architecture Model. Based on this, we developed e-CPIMAS (e-Commerce Product Information Mailing Agent System) as a case study that provides the product information's mailing service according to proposed process formality. We finally describe how these concepts may assist in increasing the efficiency reusability, productivity and quality to develop the business application and e-business agent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.427-436
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• 2016

Due to disasters such as earthquakes and landslides in urban areas, persons have been buried inside collapsed buildings and structures. Rescuers have mainly utilized detection equipment by applying sound, video and electric waves, but these are expensive and due to the directional approaches onto the collapsed site, secondary collapse risk can arise. In addition, due to poor utilization of such equipment, new human detection technology with quick and high reliability has not been utilized. To address these issues, this study develops a wireless signal-based human detection module that can be loaded into an Unmanned Aerial Vehicle (UAV). The human detection module searches for the 3D location for buried persons by collecting Wi-Fi signal and barometer sensors data transmitted from the mobile phones. This module can gain diverse information from mobile phones for buried persons in real time. We present a development framework of the module that provides 3D location data with more reliable information by delivering the collected data into a local computer in the ground. This study verified the application feasibility of the developed module in a real collapsed area. Therefore, it is expected that these results can be used as a core technology for the quick detection of buried persons' location and for relieving them after disasters that induce building collapses.

• Journal of Korea Game Society
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• v.10 no.6
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• pp.115-124
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• 2010

In the beginning brain waves were used for monkeys to control robot arm with neural activity. In recent years there are research that measured brain waves are used for the control of programs which monitor the progression of dementia or enhance of attention in children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). Moreover, low-price devices that can be used as a game control interface have become available. One of the problems associated with control using brain waves is that the mean amplitude, mean wavelength, and mean vibrational frequency of the brain waves differ from individual to individual. This paper attempts to propose a method to normalize measured brain waves using normal distribution and calculate the waveforms that can be used in controlling games. For this, a framework in which brain waves are converted in seven stages has been suggested. In addition, the estimation process in each stage has been described. In an experiment the waveforms of two subjects have been compared using the proposed method in the BCI English word learning program. The level of similarity between two subjects' waveforms has been compared with correlation coefficient. When the proposed method was applied, both meditation and concentration increased by 13% and 8%, respectively. Because the proposed regularization method is converted into a waveform fit for control functions by reducing personal characteristics reflected in the brain waves, it is fitting for application programs such as games.

• Journal of The Korean Association of Information Education
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• v.11 no.3
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• pp.317-327
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• 2007

The purpose of this study is to consider ontology theory and get to forge design and implementation of ontology-based access system which is support to the nutrition and food guide tower of Home Economics textbooks in middle school in order to offer the way of effective learning performance. It offers a model by establishing a nutrition and food guide tower access system based on Protege-2000 framework. This system is on the basis of XML, and it makes possible to work with semantic web, a next generation internet technology, and provides a meaning structure that can be shared in the field of nutrition in order to build up the fundament of knowledge an information system for the mutual operations. A learner can systemize the knowledge through a self-information access and an instructor can also check out the degree of learner's learning-accomplishment and interests, directly putting the access system into the teaching and learning process. In addition, it is supposed that the learner can maintain a balance and healthy life by internalizing his or her knowledge throughout ontology not only in a teaching and learning process but also in a daily life.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.748-755
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• 2013

This study was conducted to find a salt tolerance gene in Brassica rapa. In order to meet this objective, we analyzed data from a KBGP-24K oligo chip [BrEMD (Brassica rapa EST and microarray database)] of the B. rapa ssp. pekinensis 'Chiifu' under salt stress (250 mM NaCl). From the B. rapa KBGP-24K microarray chip analysis, 202 salt-responsive unigenes were primarily selected under salt stress. Of these, a gene with unknown function but known full-length sequence was chosen to closely investigate the gene function. The selected gene was named BrSSR (B. rapa salt stress resistance). BrSSR contains a 285 bp open reading frame encoding a putative 94-amino acid protein, and a DUF581 domain. The pSL94 vector was designed to over-express BrSSR, and was used to transform tobacco plants for salt tolerance analysis. T1 transgenic tobacco plants that over-expressed BrSSR were selected by PCR and DNA blot analyses. Quantitative real-time RT PCR revealed that the expression of BrSSR in transgenic tobacco plants increased by approximately 3.8-fold. Similar results were obtained by RNA blot analysis. Phenotypic characteristics analysis showed that transgenic tobacco plants with over-expressed BrSSR were more salt-tolerant than the wild type control under 250 mM NaCl for 5 days. Based on these results, we hypothesized that the over-expression of BrSSR may be closely related to the enhancement of salt tolerance.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.212-215
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• 2012

The antimicrobial activity of ursolic acid (UA) and oleanolic acid (OA), both triterpenoid compounds, against methicillin-resistant Staphylococcus aureus (MRSA) is controversial. We examined the antimicrobial effects of UA and OA against 19 strains of MRSA isolated from Koreans by determining minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). The data showed that the methicillin-sensitive strain S. aureus KCTC $1621^T$ was more resistant to UA and OA than that of the MRSA strains. The MBC values of UA and OA against MRSA had broad ranges; 4 to 32 ${\mu}g/ml$ and 16 to >256 ${\mu}g/ml$, respectively. It was difficult to understand the different antimicrobial activities of UA and OA among the MRSA strains, because UA and OA antimicrobial mechanisms are unknown. These results indicate that the antimicrobial effects of UA and OA against MRSA are dependent on resistance to UA and OA in each strain.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.204-211
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• 2011

A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of bridge during the passage of high speed railway vehicles. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyse accurately and evaluate with in-depth parametric studies for dynamic responses of various bridge span lengths running KTX railway locomotive up to increasing maximum speed(450km/h). Three dimensional frame element is used to model the simply supported pre-stressed concrete (PSC) box bridges for four span lengths(40~25m). Track irregularity employed as a stationary random process from the given spectral density functions and irregularities of both sides of the track are assumed to have high correlation. The high-speed railway vehicle (KTX) is used as 38-degree of freedom system. Three displacements (Vertical, lateral, and longitudinal) as well as three rotational components (Pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic amplification factors are evaluated by the developed procedure under various traveling conditions, such as track irregularity camber, train speed and ballast. The dynamic analysis such as Newmark-${\beta}$ and Runge-Kutta methods which are able to analyse considering the dynamic impact factors are compared and contrasted.

• Smart Media Journal
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• v.9 no.2
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• pp.51-62
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• 2020

Starting with the "Smart Grid National Road Map" in 2010, the Smart Grid 2030 was introduced through the basic plan and implementation plan of the intelligent power grid with the goal of building the world's first national smart grid. In this paper, we intend to build a power domain ontology based on the power business platform based on the upper and lower conceptual models of the "Smart Grid Interoperability Standard Framework and Roadmap", the standard of implementation plan. Ontology is suitable for expressing and utilizing the smart grid conceptual model because it considers hierarchical structure as knowledge defines the properties of entities and relationships between entities, but there is no research related to them. Therefore, in this paper, the upper ontology was defined as a major category for smart grid-related fields, and the lower ontology was defined as detailed systems and functions for the upper ontology to construct the ontology. In addition, scenarios in various situations that could occur in the power system were constructed and significant inference results were derived through inference engines and queries.

• Korean journal of communication and information
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• v.56
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• pp.175-193
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• 2011

This study explored how South Korean newspapers covered North Korea's second nuclear test in May of 2009. Findings show that South Korean newspapers mostly reported North Korea's nuclear experiment in relatively negative tones. Their coverage mainly focused on the influences of nuclear threat from the North on the military, political and economic areas in South Korea. However, the media's agenda settings and frames were not similar in terms of each paper's political and ideological inclination. Whereas the progressive papers, such as the Hankyoreh and the Kyunghyang Shinmun, recognized that the current nuclear issue in Korean peninsula is getting worse because of South Korea's rigorous pressure on North Korea, the conservative papers, such as the Chosun Ilbo and the Donga Ilbo, see that the deadlock between North and South mainly comes from the system malfunction of North Korea. To prevent the current impasse, the left-side papers emphasized to develop the six-party talk in dealing with North Korean issue, while the right-wing papers paid attentions to the West's sanctions on North Korea and ensuring national security.