• The Journal of Korean Physical Therapy
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• 제31권4호
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• pp.228-235
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• 2019

Purpose: This study examined the injury and rehabilitation of athletes with disabilities in racket sports projects (i.e., badminton, table tennis, and wheelchair tennis). In addition, the characteristics of each project and the differences among those projects are discussed. Methods: Business team athletes with disabilities in racket sport were enrolled as subjects (i.e., 19 badminton athletes, 19 table tennis athletes, and 19 wheelchair tennis athletes). The real conditions of the injury, injury severity, injury site, symptoms, and rehabilitation methods after injury were analyzed. Results: No significant differences were observed among the actual condition, injury severity, symptoms and the methods of rehabilitation on racket sport for athletes (i.e., badminton, table tennis, and wheelchair tennis athletes) with disability. The differences were focused mainly on the injury sites due to the characteristics of the different projects, and specific technical actions. Conclusion: This study examined the real condition of the injury, injury severity, injury site, symptoms and rehabilitation methods after the injury on the rackets (i.e., badminton, table tennis, and wheelchair tennis) athletes with disabilities. The data can be used to eliminate the incidence of injury and minimize the injury severity for racket athletes with disabilities. In addition, it can also be used for the disabled, who like racket projects, as the fundamental material to prevent injury and assist in recovery.

• Tribology and Lubricants
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• 제35권1호
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• pp.24-29
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• 2019

In this work we investigated the friction and wear characteristics of a magnesium alloy, which has been receiving much attention as a light metal in industrial applications such as automobiles and aerospace. Magnesium is one of the lightest structural material that has high specific strength, lightweight, low density and good formability. However, current issue of using magnesium alloy is that magnesium has weakness against temperature. As the temperature increases, magnesium undergoes poor creep resistance and ease of softening, and therefore, its mechanical strength decreases sharply. To solve this issue, a new type of magnesium alloy that retains high strength at high temperature has been proposed. The tribological behavior of this alloy was investigated using a tribotester with reciprocating motion and heating plate. A stainless steel ball was used as a counter surface. Results showed that extrusion process has similar wear behavior to the commonly used casting process but retains good mechanical strength and durability. The presence of an alloying element enhanced the wear properties especially in high temperature. This study is expected to be utilized as fundamental data for the replacement of high density materials currently used in mechanical industries to a much lighter and durable heat-resistant materials.

• Safety and Health at Work
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• 제13권3호
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• pp.315-325
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• 2022

Background: Firefighters are required to carry self-contained breathing apparatus (SCBA), which increases the risk of musculoskeletal disorders. This study assessed the newly recruited firefighters' internal forces and potential musculoskeletal disorders when carrying SCBA. The effects of SCBA strap lengths were also evaluated. Methods: Kinematic parameters of twelve male subjects running in a control condition with no SCBA equipped and three varying-strapped SCBAs were measured using 3D inertial motion capture. Subsequently, motion data and predicted ground reaction force were inputted for subject-specific musculoskeletal modeling to estimate joint and muscle forces. Results: The knee was exposed to the highest internal force when carrying SCBA, followed by the rectus femoris and hip, while the shoulder had the lowest force compared to the no-SCBA condition. Our model also revealed that adjusting SCBA straps length was an efficient strategy to influence the force that occurred at the lumbar spine, hip, and knee regions. Grey relation analysis indicated that the deviation of the center of mass, step length, and knee flexion-extension angle could be used as the predictor of musculoskeletal disorders. Conclusion: The finding suggested that the training of the newly recruits focuses on the coordinated movement of muscle and joints in the lower limb. The strap lengths around 98-105 cm were also recommended. The findings are expected to provide injury interventions to enhance the occupational health and safety of the newly recruited firefighters.

• 한국컴퓨터정보학회논문지
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• 제25권3호
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• pp.129-143
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• 2020

본 연구는 웨어러블 헬스케어 기기 사용자들의 수용의도를 보다 효과적으로 설명하기 위하여, 개인 혁신성에 따른 수용의도를 살펴보고 이를 확장된 통합기술수용모형(UTAUT2, Extended UTAUT) 이론에 적용하여 실증분석을 실시하고 그 결과에 따른 학술적·실무적 시사점을 제시하고자 한다. 본 연구에서 제안된 가설들을 검증하기 위해 PLS 3.0을 사용하여 구조모형을 검증하였다. 본 연구의 결과는 다음과 같이 요약될 수 있다. 첫째, 개인 혁신성이 웨어러블 헬스케어 기기의 성과기대와 노력 기대, 촉진조건, 쾌락적 동기, 가격 효용성에 매우 유의한 영향을 미치는 것으로 나타났다. 둘째, 해당 기기를 수용하고자 하는 태도에 성과기대, 노력기대, 쾌락적 동기, 가격 효용성이 웨어러블 헬스케어 기기를 수용하고자 하는 태도에 유의한 영향을 미치는 것으로 나타났다.

• Structural Monitoring and Maintenance
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• 제5권2호
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• pp.273-295
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• 2018

In this study, an investigation of a damage detection methodology for global condition assessment is presented. A particular emphasis is put on the utilization of wireless sensors for more practical, less time consuming, less expensive and safer monitoring and eventually maintenance purposes. Wireless sensors are deployed with a sensor roving technique to maintain a dense sensor field yet requiring fewer sensors. The time series analysis method called ARX models (Auto-Regressive models with eXogeneous input) for different sensor clusters is implemented for the exploration of artificially induced damage and their locations. The performance of the technique is verified by making use of the data sets acquired from a 4-span bridge-type steel structure in a controlled laboratory environment. In that, the free response vibration data of the structure for a specific sensor cluster is measured by both wired and wireless sensors and the acceleration output of each sensor is used as an input to ARX model to estimate the response of the reference channel of that cluster. Using both data types, the ARX based time series analysis method is shown to be effective for damage detection and localization along with the interpretations and conclusions.

• 한국전기전자재료학회논문지
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• 제11권10호
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• pp.940-945
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• 1998

In this paper, we obtained the data, which is required in training the neural network and diagnosing the degradation degree, by introducing the AE detection that is effective method in ordinary degradation diagnosis on activation. Aa the results of generalization tests by appling neural network to the unknown AE patterns obtained from two kinds of specimen, firstly as to evaluate an objective performance of neural network, the recognition ration for no-void specimen and 1[mm] -void specimen are appeared to be 98.9% and 92.5%, respectively. Also, in the evaluation of the adaptability of neural network with a new type of 0.2[mm] -void specimen, it is confirmed that the result appears to be 64% of recognition ratio at 94% of confidence interval coefficient in expectation output 0.2. On the other hand, the recognition capability of the neural network was confirmed by data from no-void and 1[mm] void specimen. The results prove the promising possibility of the application of ANN to discriminate specific void affecting as main degradation source at partial discharge condition in insulator containing multi-void by accummulated data base.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1997년도 춘계 학술대회 발표집
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• pp.86-89
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• 1997

This paper presents an algorithm for visualizing the traffic condition. The load of each road is updated using the incoming data collected by the devices placed at specific road crossings and junctions. The data includes the road occupancy, average speed, and vehicle types. They are analyzed to produce the 3D animation sequence of the traffic in real-time. This visualization maximizes the value of the collected data by aiding the end-users to grasp the current road situation intuitively. The traffic of a particular lane are based on the actual number of vehicles of that type passed during the last 5 minutes. This system was used in the Ministry of Construction and Public Transportation to visualize the Korean roads during the holidays around the lunar new year of 1997.

• 태양에너지
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• 제12권2호
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• pp.1-8
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• 1992

본 연구는 동계 외기온 데이타의 시각별 변동특성을 파악하기 위하여 연변동 성분 및 기간변동 성분을 제거한 일변동 성분의 매 시각별 외기온 데이타에 대해서 일교차의 발생요인에 대해서 분석하였다. 또한 동계시각별 외기온의 주파수 특성에 대해서 검토하였으며 외기온 데이타의 수식화의 가능성을 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권10호
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• pp.3275-3298
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• 2022

Cloud-based architectures for precision agriculture are domain-specific controlled and require remote access to process and analyze the collected data over third-party cloud computing platforms. Due to the dynamic changes in agricultural parameters and restrictions in terms of accessing cloud platforms, developing a locally controlled and real-time configured architecture is crucial for efficient water irrigation and farmers management in agricultural fields. Thus, we present a new implementation of an independent sensor-enabled architecture using variety of wireless-based sensors to capture soil moisture level, amount of supplied water, and compute the reference evapotranspiration (ETo). Both parameters of soil moisture content and ETo values was then used to manage the amount of irrigated water in a small-scale agriculture field for 356 days. We collected around 34,200 experimental data samples to evaluate the performance of the architecture under different agriculture parameters and conditions, which have significant influence on realizing real-time monitoring of agricultural fields. In a proof of concept, we provide empirical results that show that our architecture performs favorably against the cloud-based architecture, as evaluated on collected experimental data through different statistical performance models. Experimental results demonstrate that the architecture has potential practical application in a many of farming activities, including water irrigation management and agricultural condition control.

• 산경연구논집
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• 제14권8호
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• pp.19-25
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• 2023

Using a procurement and construction stage emphasis on the capabilities of the Sub-Contractor (SC), the present research aims to discover the types of unfair activities between the Main Contractor (MC) and SC and their influence on project completion. This research also tries to figure out solutions which can reduce unfair activities between MC and SC. Research design, data and methodology: The qualitative textual analysis was selected for the current research and has been used by numerous previous researchers commonly to review relevant themes in the prior resources and suggested for researchers who conduct a reviewing procedure to analyze meta-analysis approach for figuring out better research findings from prior resources. Results: The result indicates the prevalence and consequences of bid shopping, emphasizing the need for transparency and fair bidding practices. Late payment issues were also found to be crucial for subcontractors' financial stability, urging the implementation of prompt payment legislation and agreements. Conclusions: In conclusion, the research revealed that subcontracting is common in construction projects, with general contractors relying on multiple subcontractors to carry out specific work items. The accomplishment of building projects hinges on the collaborative efforts between the main contractor (MC) and subcontractors (SCs), each focusing on different aspects of the project.