• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1191-1226
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• 2014

The purpose of this study is to develop the evaluation criteria for the maintenance preserve of agriculture and rural heritage. The major steps for this study are 1) drafting the evaluation criteria for maintenance preservation of agriculture and rural heritage 2) verifying the evaluation criteria, and 3) determining the weighting values of the confirmed evaluation criteria. First, to derive the evaluation criteria for maintenance preservation of agriculture and rural heritage, the researcher reviewed the literature on the evaluation of agriculture and rural heritage, including research on the indexes of agriculture and rural heritage, the degree of the maintain preservation of heritage. A total of 31 evaluation criteria were selected. Second, to verify the selected 5 evaluation items and 31 evaluation indexes, the Delphi Method was implemented. Using traditional 3-step Delphi Method consisting of close-ended forms, with a panel of 41 experts, the researchers verified 5 evaluation items 31 evaluation indexes, two for each evaluation area validity. The confirmed evaluation areas are 5 items of management plan, management support system, surroundings of heritage, local network, heritage utilization and 31 criteria were preservation maintenance, performance plan, resident community composition, monitoring, act of parliament fulfillment, ecosystem management, landscape harmony, restoration and transmission plan and enhancement of residents' capability, etc. in the order. Through maintenance preservation evaluation index of agriculture and rural heritage, it can be utilized as sustainable development of plural resources.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.135-144
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• 2007

Recently, fiber-reinforced plastic(FRP) wraps are blown as an effective material for the enhancement and rehabilitation of aged concrete structures. The purpose of this investigation is to experimentally investigate behavior of concrete cylinder wrapped with FRP materials. Experimental parameters include compressive strength of concrete cylinder, FRP material, and confinement ratio. This paper presents the results of experimental studies on the performance of concrete cylinder specimens externally wrapped with aramid, carbon and glass fiber reinforced Polymer sheets. Test specimens were loaded in uniaxial compression. Axial load, axial and lateral strains were investigated to evaluate the stress-strain behavior, ultimate strength ultimate strain etc. Test results showed that the concrete strength and confinement ratio, defined as the ratio of transverse confinement stress and transverse strain were the most influential factors affecting the stress-strain behavior of confined concrete. More FRP layers showed the better confinement by increasing the compressive strength of test cylinders. In case of test cylinders with higher compressive strength, FRP wraps increased the compressive strength but decreased the compressive sham of concrete test cylinders, that resulted in prominent brittle failure mode. The failure of confined concrete was induced by the rupture of FRP material at the stain, being much smaller than the ultimate strain of FRP material.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.19-25
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• 2012

Underwater sensor networks (UWSNs) employ acoustic channels for communications. One of the main characteristics of the underwater acoustic channel is long propagation delay. Previously proposed MAC (medium access control) protocols for wireless sensor networks cannot be directly used in UWSNs due to the long propagation delay. The long propagation delay and uneven nodes deployments cause spatial fairness in UWSNs. Therefore, a new MAC protocol for UWSNs needs to be developed to provide efficient communications. In this paper, we propose an efficient MAC protocol in order to alleviate the fairness problem. In the proposed scheme, when a node receives a RTS packet, it does not immediately send back but delays a CTS packet. The node collects several RTS packets from source nodes during the delay time. It chooses one of the RTS packets based on the queue status information. And then, it sends a CTS packet to the source node which sent the chosen RTS packet. The performance of the proposed scheme is investigated via simulation. Simulation results show that our scheme is effective and alleviates the fairness problem.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.

• Information Systems Review
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• v.15 no.1
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• pp.1-24
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• 2013

This study empirically investigated inter-relationships among the influence factors on the adoption of e-commerce, which are classified as cause factor (i.e., perceived environmental uncertainty and competition), facilitators (i.e., perceived economic benefits, inter-organizational trust, suppliers' pressure and capability and asset specificity) and support factor (i.e., top management's support and organizational resource capability). The results of regression analyses showed that competition, inter-organizational trust, suppliers' pressure and capability, top management's support, and organizational resource capability have a positive impact on the adoption of e-commerce. In the analyses of inter-relationships among the influence factors, it was found that perceived environmental uncertainty positively influences suppliers' pressure and capability and perceived economic benefits, and competition has a positive impact on asset specificity. It was also observed that perceived economic benefits, inter-organizational trust and suppliers' pressure and capability positively affect top management's support, and inter-organizational trust and suppliers' pressure and capability have a positive impact on organizational resource capability. With mediating regression analyses, it was found that competition has an indirect impact on the adoption of e-commerce through the effect on perceived economic benefits, suppliers' pressure and capability, organizational resource capability and top management's support. The results of mediating regression analyses also showed that suppliers' pressure and capability and perceived economic benefits have indirect effects on the adoption of e-commerce through the effects on top management's support and organizational resource capability. From these results, it is concluded that intense competition causes the activation of facilitators, and the facilitators contribute to both the enhancement of top management support and the creation of organizational resource capability, which are directly linked to the adoption of e-commerce.

• Fire Science and Engineering
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• v.24 no.6
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• pp.45-53
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• 2010

The purpose of this study is to find out the most effective evacuation alarm sound which is the one of the most important element of the evacuation guidance system as a fundamental mechanism to minimize the damages of a fire. In this regard, a survey was conducted against the firefighting officers and the general public with questions about the general awareness of fire and their preference to various kinds of fire alarm sounds. The result showed that 1) even though the awareness of the interviewees on fire was improving while there were in familiar places like homes or works. But, when they were situated in unfamiliar locations, the fire safety awareness could not be deemed to be strong. This in turn calls for the education of the public and improvement of the existing policies for the enhancement of the fire related safety awareness in unfamiliar environments. 2) For the question about the possible time they could survive in a fire or the time required for safe evacuation, it turned out that the interviewees were thinking of the time required for evacuation to be short, which calls for proper actions. 3) When the visibility in a fire situation is highly limited, the most preferred answer for the alarm sound was a female voice, saying "The emergency exit is this way," accompanies with flashing lights of sirens for the emergency evacuation guidance.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.59-67
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• 2016

With the enhancement of built-in communication capabilities in various meters and wearable devices, which implies Internet of things (IoT), the demand of small-area embedded processors has increased. In this paper, we introduce a small-area 32-bit pipelined processor, Juno, which is available in the field of IoT. Juno is an EISC (Extendable Instruction Set Computer) machine and has a 2/3-stage pipeline structure to reduce the data dependency of the pipeline. It has a simple pipeline controller which only controls the program counter (PC) and two pipeline registers. It offers $32{\times}32=64$ multiplication, 64/32=32 division, $32{\times}32+64=64$ MAC (multiply and accumulate) operations together with 32*32=64 Galois field multiplication operation for encryption processing in wireless communications. It provides selective inclusion of these algebraic logic blocks if necessary in order to reduce the area of the overall processor. In this case, the gate count of our integer core amounts to 12k~22k and has a performance of 0.57 DMIPS/MHz and 1.024 Coremark/MHz.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.639-648
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• 2009

Earth's environment issues are introduced recently and every year the social loss have been occurred by the impact of various disaster. This kind of disaster and weather problems are the increasing reason of electricity transmission network equipment's failures because of exposing by the natural environment. The emergency and abnormal status of electricity equipment make the power outage of manufacturing plant and discomfort of people's lives. So, to protect the electricity equipment from the natural disasters and to supply the power to customer as stable, the supporting systems are required. In this paper, the research results are described the development process and the outcomes of the real-time natural disaster failure analysis information system including the describing about the impact of disaster and weather change, making the natural weather information, and linking the realtime monitoring system. As of development process, according to application development methodology, techniques are enumerated including the real time interface with related systems, the analysing the geographic information on the digital map using GIS application technology to extract the malfunction equipment potentially and to manage the equipments efficiently. Through this system makes remarkable performance it minimize the failures of the equipments, the increasing the efficiency of the equipment operation, the support of scientific information related on the mid-term enhancement plan, the savings on equipment investment, the quality upgrading of electricity supply, and the various supports in the field.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.57-68
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• 2007

The mega frame system is becoming popular for the design and construction of skyscrapers because this system exhibits structural efficiency by allowing high rigidity of the structure while minimizing the amount of structural materials to be used. Since the mega frame system is usually adopted for super high-rise buildings, the comfort of occupants may be main concerns in the practical application of this system. For the enhancement of the serviceability of mega frame structures, a semi-active tuned mass damper (STMD) is developed in this study. To this end, a Magnetorheological (MR) damper is employed replacing passive damper as a semi-active damper to improve the control effect of a conventional TMD. Since a conventional finite element model of mega frame structures has significant numbers of DOFs, numerical simulation for investigation of control performances of a STMD is impossible by using the full-order model. Therefore, a reduced-order system using minimal DOFs, which can accurately represent the dynamic behavior of a mega frame structure, is proposed in this study through the matrix condensation technique To improve the efficiency of the matrix condensation technique, multi-level matrix condensation technique is proposed using the structural characteristics of mega frame structures. The efficiency and accuracy of the reduced-order control proposed in this study and the control performance of a STMD were verified using example structures.

• Elastomers and Composites
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• v.52 no.2
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• pp.114-130
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• 2017

Enhancing the properties of rubber, such as the tensile strength, modulus, and wear abrasion, by the addition of carbon black and silica as fillers is very important for improving the performance of rubber products. In this review, we summarize the general features of 'the reinforcement of rubber by fillers' and the equations for representing the reinforcement phenomena. The rubber reinforcement was attributed to enhancement of the following: the rubber, bound rubber, formation of networks, and combination between rubber chains and silica followed by entanglement. The reinforcement capability of silica species with different surface and networked states demonstrated the importance of the connection between the silica particles and the rubber chains in achieving high reinforcement. The model involving combination followed by entanglement can provide a plausible explanation of the reinforcement of rubber by carbon black and silica because the combination facilitates the concentration of rubber chains near the filler particles, and entanglement of the rubber chains around the filler particles enforces the resistance against deformation and breakage of rubber compounds, resulting in high reinforcement.