• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.999-1010
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• 2003

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulators because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electric lines is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H$\_$$\infty$/ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.5 no.2
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• pp.59-88
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• 2010

The National Research and Development(R&D) has put a greater emphasis on development of a market- and customer-oriented technology and its commercialization in the market. To promote commercialization of technologies invented through the national R&D, many governmental and public organizations have been offering various assistance programs. In spite of these assistance programs, the commercialization rate of the Korean national R&D outcomes is relatively lower than other advanced countries including the United States and European countries. Thus, this paper analyzed 24 R&D commercialization assistance programs which are provided by several institutions in the four different nations. As a result of analysis, we recommended the areas for improvement in the Korean R&D commercialization assistance programs. Also we suggested a framework driving an effective collaboration among the institutions assisting commercialization, the institutions funding and managing R&D, and the people performing R&D.

• The Korean Journal of Community Living Science
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• v.27 no.spc
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• pp.703-714
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• 2016

Dwelling environments that can help elderly farmers to live more safely, independently, and conveniently are becoming more and more important. Many rural houses are built without any particular architectural or energy-related criteria, so most of them have poor insulation. The construction technology used is also not precise, which increases the loads for heating and cooling. Therefore, rural houses need to be improved. Also, there is more and more need for plans to realize eco-friendly dwellings, so the principle of nature-oriented plans related to the direction, insulation, or landscaping of a house is being emphasized. Insulation is one of the most effective ways to save energy for heating and cooling. This preliminary study to improve the insulation of rural houses examined three regions in South Korea: the central region, the southern region, and the Jeju Island. A field investigation was conducted on a total of 18 houses, including six from each town in the selected regions. The information was used to figure out the current status of rural houses and the characteristics of the buildings. The main living spaces are the living room for the central region and the main room in the southern region and Jeju Island. The southern regions are plane shapes surrounded by rooms, and all ventilation is accomplished by windows. The studied houses were mostly masonry structures with slate rooftops. Additions and improvements included room expansions and bathroom interior installations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1509-1521
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• 2013

Social demand for the stability of structures lead to the development of the technology to accomplish it. The non-destructive seismic technique, which is able to assess structural integrity of infrastructures, belongs to this category. Seismic technique is focused on the measurement of seismic velocity propagating through the material, and has to utilize sensors coupled to material surface, which does not allow the testing to be performed on the fly. In this paper, a general vocal microphone, which works as a non-contact sensor, was adopted to facilitate seismic testing with mobility and efficiency improved. The target of using microphones was oriented toward quality assessment of compacted subgrade, stiffness evaluation and health monitoring of concrete structures. Experimental parametric study and field applications were performed to investigate reliability and efficiency of microphones. Finally, the optimal test configuration of microphones was suggested for resonance tests and surface-wave tests.

• Information Systems Review
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• v.9 no.3
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• pp.157-181
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• 2007

Main concerns of IT project managements are concentrated on the output control and process management. IT project, however, is difficult to measure the quality of achievement, because it produces invisible and intangible outputs. Many studies have been carried on to quantify the intangible aspects of process management. However, most of them have been focused on the technological aspects. This study measures the priority of factors to manage IT project by applying the IT-BSC and PMBOK method. Established indexes include the factors of managerial, social and future-oriented perspectives to check the different aspects of project management over the technical factors. This study uses AHP method for quantitative measurement. This study can be meaningful because of following reasons. First, this study re-arranges IT project management evaluation indexes by balanced scorecard. Second, this model includes human factors of developers and users who are directly related to the project development and operation. Third, important items of each stakeholder have been separated, and the weights of each item have been quantified to have fixed values.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.5
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• pp.775-784
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• 2008

It is not easy to access very high speed Internet services at sea due to some technical and economical problems. In order to realize the very high speed Internet services at sea like on land, new communication network models based on MANET should be adopted. In this paper, a new MANET model at sea is provided, which considered the ocean environments, and the characteristics and movement of vessels. On the basis of the fact that most vessels navigate on the predetermined courses, which are the shortest paths between source and destination ports in most cases, a type of location oriented routing protocol is proposed in this paper. The Hybrid Course-Based Routing Protocol(HCBR) makes use of the static information such as courses and positions of ports to proactively find the shortest paths not only among ports but also the cross points of courses. HCBR also makes use of the locational information of vessels obtained via GPS and AIS systems to reactively discover the shortest route by which data packets are delivered between them. We have simulated the comparison of the performance of HCBR with those of LAR scheme 1 and scheme2, the most typical protocols using geographical information. The simulation results show that HCBR guarantees the route discovery even without using any control packet. They also show that HCBR is more reliable(40%) and is able to obtain more optimal routes(10%) than LAR scheme1 and scheme2 protocols.

• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.154-162
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• 2005

Objectives: To analyze the relationships of socioeconomic status(SES) to health status and health behaviors in the elderly. Methods: Data were obtained from self-administered questionnaire of 4,587 persons, older than 65 years, living in a community. We measured the sociodemographic characteristics, socioeconomic status, health status (subjective health status, acute disease, admission experience, dental state, chronic disease etc.), activities of daily living (ADL), instrumental activities of daily living (IADL), and mini-mental state examination-Korean (MMSEK). Binary and multinominal logistic regression analyses were employed to analyze factors affecting on the socioeconomic status of the elderly. Results: With regard to the SES and health status, those with a low SES had poorer subjective health states and lower satisfaction about their physical health. Also, acute disease experiences, admission rates and tooth deciduation rates were higher in those of low SES. In the view of physical and cognitive functions, the ADL, IADL and MMSE-K scores were also lower in those of low SES. However, with regard to health behaviors, lower smoking and alcohol drinking rates were found in the low SES group, and a similar trend was shown with regular physical exercise, eating breakfast, and regular physical health check-up. From these findings, we surmise that those with low SES have a poorer health condition and less money to spend on health, therefore, they can not smoke or drink alcohol, exercise and or have a physical health check-up. Conclusion: This study suggests that socioeconomic status plays an important role in health behaviors and status of the elderly. Low socioeconomic status bring about unhealthy behavior and poor health status in the elderly. Therefore, more specific target oriented(esp. low SES persons) health promotion activities for the elderly are very important to improve not only their health status, but their health inequity also.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.451-455
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• 2015

The buffalo is an important livestock resource in several countries of South Asia and the Mediterranean regions. However, reproductive efficiency is compromised due to known problems of biological and management origins, such as lack of animal selection and poor nutrition. Under optimal conditions puberty is attained at 15 to 18 months in river buffalo, 21 to 24 months in swamp buffalo and is influenced by genotype, nutrition, management and climate. However, under field conditions these values deteriorate up to a significant extant. To improve reproductive efficiency, several protocols of oestrus and ovulation synchronization have been adopted from their use in commercial cattle production. These protocols yield encouraging pregnancy rates of (30% to 50%), which are comparable to those achieved in buffaloes bred at natural oestrus. The use of sexed semen in buffalo heifers also showed promising pregnancy rates (50%) when compared with conventional non-sexed semen. Assisted reproductive technologies have been transferred and adapted to buffalo but the efficiency of these technologies are low. However, these latest technologies offer the opportunity to accelerate the genetic gain in the buffalo industry after improving the technology and reducing its cost. Most buffaloes are kept under the small holder farming system in developing countries. Hence, future research should focus on simple, adoptable and impact-oriented approaches which identify the factors determining low fertility and oestrus behaviour in this species. Furthermore, role of kisspeptin needs to be explored in buffalo.

• Architectural research
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• v.13 no.3
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• pp.11-18
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• 2011

With the rapid development of computer technology and ongoing destruction of traditional buildings, more and more attention is paid to digital methods for the design and preservation of traditional buildings. Unlike 2D methods, Building Information Modeling (BIM) provides an object-oriented and parametric digital representation way for traditional building components. However, one of the main limitations currently is that parametric information cannot be exchanged between BIM software packages. Therefore each kind of software must have their own parametric library which causes extensive works. In this research, the authors developed an open BIM-based library using an XML parametric approach to solve the above problems, represented traditional components according to an XML schema, and parametrically implemented these XML files in a browser which can be accessed by users for their easy component edit and selection. And then based on the XML file of one component, implemented an Add-on in ArchiCAD for users to parametrically edit and directly utilize. Thus based on these XML files, a browser for users' view and selection purpose and an add-on for users' application purpose were developed. Future research will focus on implementing these XML files in other BIM tools like Revit and Digital Project. If the whole library was to be completed based on this XML approach, an open BIM-based library would be established that all kinds of BIM software users could apply this parametric library for easy modeling of traditional houses.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.95-100
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• 2011

Due to rapid growth and development of telecommunication information technology, interest has been amplified regarding ubiquitous network computing and user-oriented service. Also, the rapid development of related technologies has been a big spotlight. Smart phone, with features such as a PC with advanced features is a mobile phone. According to environment and infrastructure development, a variety of mobile-based application software to provide various kinds of information and services has been released. However, most of them are provider-driven information systems and aim to provide large amounts of information simply to an unspecified number of users. Therefore, customized or personalized provision of information and service explained earlier for individual users has been hardly come true. According to background and need, this study wants to design and implement recommendations system for personalization and customization in mobile environments. To acquire more accurate recommendation results, recommendation system shall be composed using the Hybrid Filtering. Effective information recommendation according to user's situation by using user's context-information of purpose and location that are available in mobile devices before running the filtering of the information to improve the quality of recommendations.