• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.4
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• pp.163-170
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• 2023

In the fluid-structure interaction analysis, the finite element formulation is performed for the wave equation for dynamic fluid pressure, and the dynamic pressure is defined as a degree of freedom at the fluid nodes. Therefore, to connect the fluid to the structure, it is necessary to connect the degree of freedom of fluid dynamic pressure and the degree of freedom of structure displacement through an interface element derived from the relationship between dynamic pressure and displacement. The previously proposed fluid-structure interface elements use conformal finite element meshes in which the fluid and structure match. However, it is challenging to construct conformal meshes when complex models, such as water purification plants and wastewater treatment facilities, are models. Therefore, to increase modeling convenience, a method is required to model the fluid and structure domains by independent finite element meshes and then connect them. In this study, two fluid-structure interface elements, one based on constraints and the other based on the integration of nonsmooth functions, are proposed in nonconformal finite element meshes for structures and fluids, and their accuracy is verified.

• Physical Therapy Korea
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• v.30 no.3
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• pp.194-201
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• 2023

Background: Falls are a common and serious problem in the elderly population. Muscle strength and balance are important factors in the prevention of falls. The Y-balance test (YBT) is used to assess dynamic postural control and shows excellent test-retest reliability. However, no studies have examined the relationship between lower-limb strength and YBT scores in elderly women. Objects: This study aimed to examine the relationship between lower-limb strength and YBT scores in elderly women. Methods: Thirty community-dwelling elderly women participated in the study. Lower-limb strength including hip flexor, hip extensor, hip abductor (HAB), hip adductor (HAD), knee flexor, knee extensor, ankle dorsiflexor, and ankle plantar flexor (PF) muscles was examined using a smart KEMA strength sensor (KOREATECH Inc.), and the YBT was used to assess dynamic balance. Relationship between lower-limb strength and YBT was demonstrated using a Pearson's correlation coefficient. Results: HAB strength (r = 0.388, p < 0.05), HAD strength (r = 0.362, p < 0.05), and ankle PF strength (r = 0.391, p < 0.05) positively correlated with the YBT-anterior direction distance. Ankle PF strength was positively correlated with the YBT-posteromedial direction distance (r = 0.396, p < 0.05) and composite score (r = 0.376, p < 0.05). Conclusion: The results of this study suggest that HAB, HAD, and ankle PF strengths should be considered for dynamic postural control in elderly women.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.161-168
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• 2010

The bonded tendon was adopted to the reactor building of some operating nuclear power plants in Korea and the assessment of the effective prestress force on the bonded tendon is being issued as an important pending problem for continuous operation beyond their design life. The sensitivity analysis of various parameters was carried out to evaluate the effective prestress force using the system identification technique and the optimal parameters were determined for SI technique in this study. The 1/5 scaled post-tensioned concrete beams with the bonded tendon type were manufactured and in order to investigate the relationship of the natural frequency and the displacement to the effective prestress force, impact test, SIMO sine sweep test and bending test using the optical fiber sensor and the compact displacement transducer were carried out. As a result of tests, both the natural frequency and the displacement show the good relationship with the effective prestress force and both parameters are available for the SI technique to estimate the effective prestress force.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2B
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• pp.121-129
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• 2009

In this study, dam-break flows are simulated numerically by using an efficient and accurate Cartesian cut-cell mesh system. In the system, most of the computational domain is discretized by the Cartesian mesh, while peculiar grids are done by a cutcell mesh system. The governing equations are then solved by the finite volume method. An HLLC approximate Riemann solver and TVD-WAF method are employed to calculation of advection flux of the shallow-water equations. To validate the numerical model, the model is applied to some problems such as a steady flow convergence on an ideal bed, a steady flow over an irregular bathymetry, and a rectangular tank problem. The present model is finally applied to a simulation of dam-break flow on an experimental channel. The predicted water surface elevations are compared with available laboratory measurements. A very reasonable agreement is observed.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.69-87
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• 2023

Background: Swallowing function deterioration is a common problem experienced by older adults worldwide. Many studies have been conducted to improve swallowing function in older adults; however, due to differences in intervention methods and study designs, it is difficult to draw a common conclusion. This study aimed to analyze trends and intervention methods in studies of swallowing function intervention for older adults conducted from 2010 to 2022, to establish a systematic approach for developing interventions to improve swallowing function in older adults and to provide evidence for this approach. Methods: Literature research was conducted for studies published between 2010 and 2022 that applied to swallow function interventions to adults aged 60 years or older. Databases including PubMed, Medline, RISS, Science On, KISS, and KCI were used. From a total of 1,164 articles searched using keywords, 20 articles were selected for final analysis. Results: The number of published articles steadily increased over time, and the intervention period was most commonly 6 or 8 weeks. The types of interventions included focused exercises to improve oral muscle strength in 12 articles and programs incorporating education, practice, and expert management in 8 articles. Among the focused exercises, tongue-strengthening exercises were most common in 4 articles. The evaluation variables for intervention effects were muscle strength evaluation, oral function evaluation, quality of life, and oral health and hygiene status. Muscle strength and oral function evaluations were statistically significant in focused exercise interventions, while the quality of life and oral health and hygiene status was significant in program interventions. Conclusion: This literature review is meaningful as a study that can be used to select the intervention period and program contents when planning an elderly swallowing intervention program.

• The Korean Journal of Franchise Management
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• v.5 no.2
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• pp.25-49
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• 2014

This study is to examine the impact of sales franchisor's relationship-oriented efforts(flexibility, problem solving support, customization, information exchange, and supervisor characteristics) on relationship quality(satisfaction, trust, and commitment) and recontract intentions. In order to analyze proposed model, this study collected the 233 franchisees with owner or hired manager. The data were analyzed with SPSS/PC 18.0 and AMOS 18.0. First, to test unidimensionality and nomological validity of the measures of each construct we employed a scale refinement procedure. The result of reliability test with confirmatory factor analysis warranted unidimensionality of the measures for each construct. The findings are as follows: First, relationship-oriented efforts had positive effects on relationship quality (satisfaction, trust, and commitment) of franchisee. Second, satisfaction had positive effect on trust, but did not on recontract intentions. Third, trust had positive effects on commitment and recontract intentions, respectively. Finally, commitment had a positive effect on recontract intentions. At the end of this paper, managerial implications and limitations and future research directions were suggested.

• The Korean Journal of Franchise Management
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• v.2 no.2
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• pp.84-94
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• 2011

Domestic franchise industry is growing rapidly as a promising business in 21st century and also ordinary people business. Domestic franchise headquarters and franchisees have increased exponentially. However, because of tough competition in the industry, headquarters' lack o fawareness of recruiting and managing franchisees, and reckless expansion strategy for the structural problem of profit structure and lack of experts, systematic management and support system are not going well. For these reasons, the need of franchisee management system is growing up in this industry. Domestic franchise industry is focused on appearance, the volume, while absence and lowness of internal management systems are making stores shut down and conflicts proving necessity of management system. In this study, we find and study the way to compensate these problems and systematize by cooperating within surance companies to manage franchisees, and eventually to be able to set up and use new systems including franchise management system, initial services, on goin gservices, lega lservices, tax services, labor services, and financial analysis and planning services.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.169-170
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• 2020

Although Busan Port is a world-class transshipment port, it is geographically divided and, despite the continuous increase in transshipment volume, ITT port integrated operation is not being performed, reducing port operation efficiency. In addition, the operation raises the problem of inefficiency in social and economic aspects, along with an increase in the volume of transshipment transport and the resulting increase in transshipment transport costs. This paper deals with the necessity of forming an integrated operation organization to carry out the ITT joint dispatch in the process of improving the ITT efficiency in Busan Port, and the organization structure centering on the transport companies and freight owners performing the Busan Port ITT. We intend to make a proposal for the establishment of an integrated operation organization in the form of a consortium and support plans. In addition, through analysis of implications, the role of the ITT stakeholders in Busan Port and related organizations will be addressed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1841-1857
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• 2023

CenterNet, a novel object detection algorithm without anchor based on key points, regards the object as a single center point for prediction and directly regresses the object's height and width. However, because the objects have different sizes, directly regressing their height and width will make the model difficult to converge and lose the intrinsic relationship between object's width and height, thereby reducing the stability of the model and the consistency of prediction accuracy. For this problem, we proposed an algorithm based on the regression of the diagonal half-length and the center angle, which significantly compresses the solution space of the regression components and enhances the intrinsic relationship between the decoded components. First, encode the object's width and height into the diagonal half-length and the center angle, where the center angle is the angle between the diagonal and the vertical centreline. Secondly, the predicted diagonal half-length and center angle are decoded into two length components. Finally, the position of the object bounding box can be accurately obtained by combining the corresponding center point coordinates. Experiments show that, when using CenterNet as the improved baseline and resnet50 as the Backbone, the improved model achieved 81.6% and 79.7% mAP on the VOC 2007 and 2012 test sets, respectively. When using Hourglass-104 as the Backbone, the improved model achieved 43.3% mAP on the COCO 2017 test sets. Compared with CenterNet, the improved model has a faster convergence rate and significantly improved the stability and prediction accuracy.

• Convergence Security Journal
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• v.22 no.1
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• pp.121-127
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• 2022

Recently, social issues related to cryptocurrency mining are continuously occurring at the same time as cryptocurrency prices are rapidly increasing. In particular, since cryptocurrency can be acquired through cryptographic operation, anyone with a computer can easily try mining, and as the asset value of major cryptocurrencies such as Bitcoin and Ethereum in creases, public interest is increasing. In addition, the number of cases where individuals who own high-spec computers mine cryptocurrencies in various places such as homes and businesses are increasing. Some miners are mining at companies or public places, not at home, due to the heat problem of computers that consume a lot of electrical energy, causing various problems in companies as well as personal moral problems. Therefore, this study studies the technology to obtain evidence for the traces of mining attempts using the Windows artifacts of the computers that mined cryptocurrency. Through this, it is expected that it can be used for internal audit to strengthen corporate security.