• 한국물환경학회지
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• 제29권6호
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• pp.730-738
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• 2013

In recent years, low impact development (LID) has emerged as an effective approach to control stormwater in an urban area, and watershed and stormwater managers need modeling tools to evaluate alternative plans for controlling stormwater. This study illustrates how to design and evaluate the effect of non-point pollutant management using SUSTAIN which is developed by USEPA. SUSTAIN can provide evaluating, selecting, and placing LID facilities in an urban catchment based on user-defined cost-effectiveness criteria. Also, this paper suggests a minimal methodology for estimating model parameters for modeling an ungauged urban catchment to reflect the situation of typical Korean urban interested catchments which are usually ungauged. In addition, the optimal length of various LID facilities and the optimal number of units in our test catchment are estimated.

• 한국수학교육학회지시리즈A:수학교육
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• 제39권1호
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• pp.71-80
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• 2000

As the new century begins, it is clear that K-l2 education is going through a major change. The increasing power and affordability of personal computers along with wide spread use of the Internet has not only changed the landscape for communication but it has opened up new and exciting opportunities for education. One of the ways that Internet could help improve education is to act as an interactive communication link to gather the knowledge and experience of all the teachers and to serve as an open forum for discussing and exchanging innovative ideas. But developing a successful site is not an easy task since the success of the site depends on the level of participation and cooperation of teachers. In this paper, learnings derived from the development of an interactive web based resource center for K-12 mathematics teacher are described and recommendations for developing an effective site for teachers are suggested. The development of an interactive resource center for mathematics teachers showed that while interest for a web based resource is very high, the main obstacle for effective teacher participation is lack of easy accessibility of internet by teachers, and lack of computer and internet training for teachers. The technical issues regarding hardware installation, software development and cost were minimal. Accessibility will improve in time as more and more schools are connected to the internet, but this alone will not be enough. The study suggests that in order to bring together teachers on the internet more effort needs to be made in training teachers on the use of computers and the internet.

• 전기전자학회논문지
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• 제25권1호
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• pp.212-217
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• 2021

Premature contraction arrhythmia is the most common disease among arrhythmia and it may cause serious situations such as ventricular fibrillation and ventricular tachycardia. Most of arrhythmia clasification methods have been developed with the primary objective of the high detection performance without taking into account the computational complexity. Also, personalized difference of ECG signal exist, performance degradation occurs because of carrying out diagnosis by general classification rule. Therefore it is necessary to design efficient method that classifies arrhythmia by analyzing the persons's physical condition and decreases computational cost by accurately detecting minimal feature point based on only QRS features. We propose method for personalized specific classification of premature contraction arrhythmia based on QRS features in smart healthcare environments. For this purpose, we detected R wave through the preprocessing method and SOM and selected abnormal signal sets.. Also, we developed algorithm to classify premature contraction arrhythmia using QRS pattern, RR interval, threshold for amplitude of R wave. The performance of R wave detection, Premature ventricular contraction classification is evaluated by using of MIT-BIH arrhythmia database that included over 30 PVC(Premature Ventricular Contraction) and PAC(Premature Atrial Contraction). The achieved scores indicate the average of 98.24% in R wave detection and the rate of 97.31% in Premature ventricular contraction classification.

• Coupled systems mechanics
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• 제11권2호
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• pp.151-166
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• 2022

Peltier cells have low efficiency, but they are becoming attractive alternatives for affordable and environmentally clean cooling. In this line, the current article develops closed-form and semianalytical solutions to improve the temperature distribution of Bi₂Te₃ thermoelements. From the distribution, the main objective of the current work-the optimal electric intensity to maximize cooling-is inferred. The general one-dimensional differential coupled equation is integrated for linear and quadratic geometry of thermoelements, under temperature constant properties. For a general shape, a piece-wise solution based on heat flux continuity among virtual layers gives accurate analytical solutions. For variable properties, another piece-wise solution is developed but solved iteratively. Taking advantage of the formulae, the optimal intensity is directly derived with a minimal computational cost; its value will be of utility for more advanced designs. Finally, a parametric study including straight, two linear, barrel, hourglass and vase geometries is presented, drawing conclusions on how the shape of the thermoelement affects the coupled phenomena. A specially developed coupled and non-linear finite element research code is run taking into account all the materials of the cell and using symmetries and repetitions. These accurate results are used to validate the analytical ones.

• Archives of Plastic Surgery
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• 제48권4호
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• pp.433-439
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• 2021

Acellular dermal matrices (ADM) are a novel graft. The goal of this systematic review is to evaluate the evidence behind differences in human and porcine ADM, irrelevant of manufacturing method, and to determine if there is enough of an evidence base to change clinical practice. An extensive literature search was performed through MEDLINE and Embase with search terms defining a population, intervention and outcome. Title and abstract exclusion were performed with other exclusion criteria. In 191 articles were found after exclusion of duplicates, with only 29 remaining following exclusions. Ten studies were found to have level I and II evidence (I=3, II=8), of which two were histopathological, one was an animal model, one was a systematic review, and six were clinical. The remaining studies were reviewed and considered for discussion, but did not hold high enough standards for medical evidence. Strong clinical evidence already exists for the use of human ADM, but questions of access, cost, and ethics require consideration of a xenograft. Histopathologically, evidence suggests minimal long-term differences between human and porcine ADM, although there is a short acute immune response with porcine ADM. Clinically, there is limited difference in outcomes, with a small range in effect of different ADM preparations. Considering the effectiveness of ADM in wound healing, more high-level research with appropriate statistical analysis to facilitate a future meta-analysis is recommended to justify a transition from human to porcine ADM.

• International Journal of Internet, Broadcasting and Communication
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• 제15권1호
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• pp.33-39
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• 2023

Social networking is gaining speed and has grown indispensable as technology develops. As a result, social media, particularly Facebook, Instagram, and influencer marketing, are replacing conventional marketing trends. The top 15 search terms for Mongolian women between the ages of 18 and 34 in 2019 on Facebook were cosmetics and shopping. Companies use social media, the main tool of social media, to promote their products while simultaneously increasing productivity at a minimal cost. In Mongolia, finding out about cosmetic brand products on social media is rather usual. The impact of social media influencers on the purchasing of cosmetic brands must thus be researched. We aimed to find out the relationship between attractiveness, authenticity, communication ability, and influence, which are characteristics of beauty influencers, on product purchase intention and identification between consumers and followers (information acceptance, purchase intention). Communication ability and influence appeared to have a statistically significant positive (+) effect on identification. On the other hand, attractiveness, communication ability, and influence all showed a statistically significant positive (+) effect on information acceptance. Identification and information acceptance has s significant positive effect on purchase intention.

• 한국IT서비스학회지
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• 제21권5호
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• pp.15-28
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• 2022

Recently, government agencies are actively adopting the platform model as a means of public policy. However, existing studies on the public platform are minimal and have focused on user experiences or the possibility of public usage of the platform model. Now the research concerning building governance structure and utilizing network effects of the platform after adopting the platform model in the public sector is keenly required. This study intended to ignite academic dialogue on the governance of public platforms in the context of digital transformation. This study focused on a case of the 'Special delivery,' a public delivery app established by Gyeonggi-do. In order to analyze the characteristics of the public platform and its governance structure, data were collected from press releases, policy reports, and news articles. Data was analyzed using the frame of Hagui's platform design factors and Ansell & Gash's collaborative governance model. The results of the public platform analyses showed 1) incompleteness in the value trade-off accounting, which was designed for platform business based on general cost-benefit analysis, and 2) a closed governance structure that limits direct participation of diverse user groups(i.e., service provider, customer) in order to enhance providers' utility by preventing customers' excessive online activities. The results of this study provided theoretical and policy implications regarding designing the strategy for accounting for value trade-offs and functioning governance structure for public platforms.

• International journal of advanced smart convergence
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• 제12권2호
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• pp.153-158
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• 2023

Most agriculture plantings are based on traditional farming and demand a lot of human work processes. In order to improve the efficiency as well as the productivity of their farms, modern agricultural technology was proven to be better than traditional practices. Internet of Things (IoT) is usually related in modern agriculture which provides the farmer with a real-time monitoring condition of their farm from anywhere and anytime. Therefore, the application of IoT with a sensor to measure and monitors the humidity and the temperature in the mushroom farm that can overcome this problem. This paper proposes an IoT based monitoring system forindoor Ganoderma lucidum cultivation at a minimal cost in terms of hardware resources and practicality. The results show that the data of temperature and humidity are changing depending on the weather and the preliminary experimental results demonstrated that all parameters of the system were optimized and successful to achieve the objective. In addition, the analysis results show that the quality of Ganoderma lucidum produced on the research method conforms to regulations in Vietnam.

• Advances in concrete construction
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• 제15권1호
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• pp.41-46
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• 2023

Sport has no age limit and can be done anywhere and in any condition with minimal equipment. The existence of sports spaces in all parts of the world is considered a citizen's right. One of the activities carried out in this field is installing sports equipment and structures in parks and encouraging citizens to use this equipment for physical health with the least cost and facilities. Installing sports structures in open spaces such as parks is a practical step for developing citizens' sports. Although using devices in parks is acceptable, it is more critical to meet scientific and technical standards. The components of these structures must have high strength and endurance against changes in environmental conditions such as humidity, temperature difference, and corrosion. Among the various causes of material degradation, corrosion has always been one of several fundamental causes of metal equipment failure. Sports structures in open spaces are not safe from corrosion. Uniform corrosion is the most common type of corrosion. This corrosion usually occurs uniformly through a chemical or electrochemical reaction across the surface exposed to the corrosive environment. Rust and corrosion of outdoor sports structures are examples of this corrosion. For this reason, in this research, with the green synthesis of silica nanoparticles and its application in outdoor sports structures, the life span of these structures can be increased for the use of physical exercises as well as their quality.

• Advances in materials Research
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• 제12권4호
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• pp.331-349
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• 2023

Foam concrete can be considered as environmental friendly material due to its low weight, its minimal cost and a possibility to add waste materials in its production. This paper investigates the possibility of producing foam concrete with waste glass as powder and aggregate. Then, the effect of using waste glass on strength and drying shrinkage of foam concrete was examined. Also, the effect of incorporating polypropylene fibers (12 mm length and proportion of 0.5% of a mix volume) on distribution of waste glass as coarse particles within 1200 kg/m³ foam concrete mixes was evaluated. Waste glass was used as powder (20% of cement weight), as coarse particles (25%, 50% and 100% instead of sand volume) and as fine particles (25% instead of sand volume). From the results, the problem of non-uniform distribution of coarse glass particles was successfully solved by adding polypropylene fibers. It was found that using of waste glass as coarse aggregate led to reduce the strength of foam concrete mixes. However, using it with polypropylene fibers in combination helped in increasing the strength by about 29- 50% for compressive and 55- 71% for splitting tensile and reducing the drying shrinkage by about (31- 40%). In general, not only the fibers role but also the uniformly distributed coarse glass particles helped in improving and enhancing the strength and shrinkage of the investigated foam concrete mixes.