• Journal of Adhesion and Interface
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• v.12 no.3
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• pp.88-93
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• 2011

Optimal dispersion and fabrication conditions of carbon nanotube (CNT) embedded in phenolic resin were determined by electrical resistance measurement; and interfacial property was investigated between plasma treated carbon fiber and CNT-phenolic composites by electro-micromechanical techniques. Wettability of carbon fiber was improved significantly after plasma treatment. Surface energies of carbon fiber and CNT-phenolic nanocomposites were measured using Wilhelmy plate technique. Since surface activation of carbon fiber, the advancing contact angle decreased from $65^{\circ}$ to $28^{\circ}$ after plasma treatment. It was consistent with static contact angle results of carbon fiber. Work of adhesion between plasma treated carbon fiber and CNT-phenolic nanocomposites was higher than that without modification. The interfacial shear strength (IFSS) and apparent modulus also increased with plasma treatment of carbon fiber.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.401-409
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• 2021

This study was conducted to investigate the effects of static recovery and dynamic recovery methods on heart rate, blood lactic acid concentration, and blood glucose during recovery after walking at the speed of 80bpm and 130+30bpm upon trekking of forest slopes in Taejo Mountain in Cheonan. 9 men in their 20s and 30s who had no abnormality in walking was subject to this experience. The result of through static recovery and dynamic recovery methods while trekking at the speed of 80bpm and 130+30bpm were analyzed by two-way repeated ANOVA. When there was a significant difference, the repeated method of contrast was applied to compare and analyze. The heart rate at 80bpm condition was significantly different depending on the method(p=.008) and time(p=.000) and there was no significant difference in blood lactic acid concentration for the recovery method(p=.401), but there was a significant difference depending on the time(p=.000). Blood glucose did not show significant difference according to the recovery method(p=.093), and there was significant difference depending on the time of static recovery method(p=.002). The heart rate in 130bpm + 30bpm condition was significantly different depending on to the method(p=.002) and time(p=.000), blood lactic acid concentration was significantly different depending on the method(p=.001) and time(p=.000), and blood glucose concentration was not significantly different between the time(p=090) and the method(p=.721).

• Journal of Wetlands Research
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• v.21 no.1
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• pp.27-33
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• 2019

The future water management needs decentralization of facilities, diversity of technology and integration of management to overcome the waste of financial resources and increase in scale of facilities that occurred from centralized water management. In addition, citizen's environmental awareness and participation is important because all infrastructure installed in the watershed where citizens live should have the function of water management. Therefore, the research was performed by investigating the citizen's recognition about urban environment와 LID application to analyze citizen's perceptions and analyze the feasibility and possibility of LID application. The LID awareness of citizens was about 59%, but only about 46% of citizens agreed on the extension of application. However, after contacting LID photographs and information, 90% of respondents agreed on the application of LID, and 94% of respondents were able to distinguish between grey infrastructure and LID infrastructure. Citizens appeared to have a tendency to recognize green spaces as multi-functional LID infrastructure or green infrastructure. If citizens recognize multi-functional LIDs only as landscapjng area, it will be very difficult to extend the LID on the city areas. Therefore, for the extended application of the LID facilities, it is necessary to use public relations strategy to utilize the results and visual data on the actual effect verification. In addition, as every social infrastructure is formed in watershed where citizens live, it is necessary to plan and manage the infrastructure through governance with citizen participation.

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.31-39
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• 2019

This research examined the changes that fast-growing voice-based devices would bring in the media multitasking environment. Based on the theoretical background that information processing efficiency improves when performing multiple tasks requiring different resource structures at the same time, we conducted an experiment where participants searched for information with voice-based or screen-based devices while performing an additional visual task. Results showed that both task performance environment and interface modality had significant main effects on cognitive load. The overall cognitive load level was higher in the voice interface group, but the difference in cognitive load between the two groups decreased in a multitasking environment where the additional visual resources was required. The visual task performance was significantly higher when using the voice interface than the screen interface. Our findings suggest that voice interfaces offered advantages in the cognitive load and task performance by distributing two tasks to the auditory and visual channels. The results of this study imply that voice-based devices have the potential to facilitate efficient information processing in the screen-centric environment where visual resources collide. We provided theoretical evidence of resource distribution using multiple resource theory and tried to identify the advantages of the voice interface more specifically based on the threaded cognition model.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.830-839
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• 2019

The purpose of this study is to analyze the effect of sport sponsorship on the advertising effectiveness by distinguishing products of high sponsorship products from low sponsorship products. For this study, 450 samples who directly spectated their game were selected using convenience sampling method, finally 426 data were used except data which didn't respond or trustlessly responded. Data was collected through questionnaires. Data was analyzed through PASW 19.0 version frequency analysis, reliability analysis, factor analysis, independent sample t-test analysis, one-way ANOVA analysis paired sample t-test analysis was performed. All tests were performed using a .05 significance level. The results are as follows. First, This is the Result of T-test between brand effectiveness and gender. There is a non difference between male and female. Second, The results showed that there was statistically significant difference between the low perception perceived quality and low perceived sponsor familiarity according to current level of Education. Thirdly, This is the Result of T-test between low involvement perceptual quality, low sponsor friendly image and high involvement perceptual quality, high sponsor friendly image. There is a difference.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.358-366
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• 2019

Purpose: This paper aims to clarify the problems and to examine the improvement methods by investigating the management condition of local-designated cultural property of which management is relatively poor in comparison with state-designated cultural heritage. Method: In order to grasp the management situation of the local-designated cultural heritage, a research on cultural heritage management situation and problems will be carried out with 35 cultual heritages in Goryeong-gun. Also, the improvement methods about the property type vulnerability on the basis of interview with cultual property managers, fire-fighting officers and civil servants, etc. Results: Local cultural heritages were investigated to be very vulnerable to the fire of wooden buildings, the theft of movable cultural heritages, and the effects of wind and water damage. It is because cultural heritages are scattered over wide areas fundamentally. As the result, it has difficulty in the patrols of police officers and fire fighters, and in the situation that it lacks disaster monitoring and CCTV for countermeasures to replace them, electronic security including fire hydrant, sensors, etc and fire extinguishing facilities and so on. It is difficult for local governments managing local-designated cultural heritages to enhance their management systems directly due to their lack of budget and manpower. Conclusion: In order to strengthen disaster and safety management system for the cultural heritages designated by local governments, they have to clarify disaster countermeasure task of fire fighting, police, and cultural heritage managers prepare their manuals, and systematize them through disaster drill mainly in local autonomous governments. Also, so as to establish a surveillance system every day, they have to enhance the community for local cultural heritage manage consisting of local volunteer fire departments, local voluntary disaster prevention organizations, volunteers, etc.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.2
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• pp.41-56
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• 2019

Cloud manufacturing is a new concept of manufacturing process that works like a single factory with connected multiple factories. The cloud manufacturing system is a kind of large-scale CPS that produces products through the collaboration of distributed manufacturing facilities based on technologies such as cloud computing, IoT, and virtualization. It utilizes diverse and distributed facilities based on centralized information systems, which allows flexible composition user-centric and service-oriented large-scale systems. However, the cloud manufacturing system is composed of a large number of highly heterogeneous subsystems. It has difficulties in interconnection, data exchange, information processing, and system verification for system construction. In this paper, we derive the user requirements of various aspects of the cloud manufacturing system, such as functional, human, trustworthiness, timing, data and composition, based on the CPS Framework, which is the analysis methodology for CPS. Next, by analyzing the user requirements we define the system requirements including scalability, composability, interactivity, dependability, timing, interoperability and intelligence. We map the defined CPS system requirements to the requirements of oneM2M, which is the platform standard for IoT, so that the support of the system requirements at the level of the IoT platform is verified through Mobius, which is the implementation of oneM2M standard. Analyzing the verification result, finally, we propose a large-scale cloud manufacturing platform based on oneM2M that can meet the cloud manufacturing requirements to support the overall features of the Cloud Manufacturing CPS with dependability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.45-51
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• 2021

The purpose of this study was to investigate the effect of applying whole body vibration exercise at 30 Hz on the thickness and mechanical properties of the erector spinae. The study population included 24 adults (11 male and 13 female) in the N region. The subjects were divided into two groups, a 30Hz whole body vibration exercise(WG, n=12) and an LSG(12 subjects). Changes in the thickness and mechanical properties of the erector spinae were analyzed before the exercises and after four and eight weeks of exercises using a two-way repeated analysis of variance with a statistical significance level of α=0.05. When there was an interaction between the groups and measurement times, post hoc analyses were conducted at a statistical significance level of α=0.01. The thickness, frequency, stiffness and strain of the erector spinae muscles were significantly different in each time period and in the interaction between time period and the group (P<0.05), and recovery was significantly different only in each time period (P<0.05). Thus, 30Hz whole body vibration exercise had a positive effect on the thickness and mechanical properties of the erector spinae. The results of this preliminary study suggest that whole body vibration exercise may find a place as a lumbar stabilization exercise in clinical practice in the future.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.23-36
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• 2005

The main obstacle hindering the wide deployment of identity-based cryptosystem is that the entity responsible for creating the private key has too much power. As a result, private keys are no longer private. One obvious solution to this problem is to apply the threshold technique. However, this increases the authentication computation, and communication cost during the key issuing phase. In this paper, we propose a new effi ient model for issuing multiple private keys in identity-based encryption schemes based on the Weil pairing that also alleviates the key escrow problem. In our system, the private key of a user is divided into two components, KGK (Key Description Key) and KUD(Key Usage Desscriptor), which are issued separately by different parties. The KGK is issued in a threshold manner by KIC (Key Issuing Center), whereas the KW is issued by a single authority called KUM (Key Usage Manager). Changing KW results in a different private key. As a result, a user can efficiently obtain a new private key by interacting with KUM. We can also adapt Gentry's time-slot based private key revocation approach to our scheme more efficiently than others. We also show the security of the system and its efficiency by analyzing the existing systems.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.293-299
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• 2022

Recently, various stakeholder are interested in microplastic to cause pollution of the marine's ecosystem and effort to conduct study of product's life cycle to reduce pollution of marine's ecosystem. The micorplastic refer to materials of the nano- to micro- sized units and it can be classified into primary and secondary. The primary microplastic mean the manufactured for use in the specific field such as the microbead of the cosmetic or cleanser. also, secondary mean the unintentionally generated during use of the product such as the textile crumb by the doing the laundry. Tire and Road Wear Particles(TRWPs) are also defined as secondary microplastic. Typically, TRWPs are created by friction between the tread compound's rubber of the tire and the surface of the road du ring the driving cars. Most of the generated TRWPs exist on the roadside and some of them were carried to marine by the rainwater. In this study, we perform the quantitative analysis of the TRWPs existed in fine dust at the roadside. So, we collected the dust from the roadside in Chungcheongnam-do's C site with a movement of 1,300 cars per the hour. The collected samples were separated according to size and density. And shape analysis was performed using the Scanning Electron Microscope(SEM). We were possible to discover a lot of TRWPs at the fine dust of the 100 ± 20 ㎛. And we analysis it u sing the Thermo Gravimetric Analysis(TGA) and Gas Chromatography/Mass Spectrometer(GC/MS) for the quantitative components from the tire. As a result, it was confirmed that TRWPs generated from the roadside fine dust were included the 0.21 %, and the tire and road components in the generated TRWPs consisted of the 3:7 ratio.