• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.721-726
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• 1999

The fishways on Namdae-cheon and Osib-cheon and the use of migratory fishes were investifated from July 1998 through Jung 1999. There are three types of fishways on these rivers. Those are baffled fishways, fish ladder, and fish ladder with gabion. Namdae-cheon has 7 baffled fishways and 19 fish ladder, and Osib-cheon has only fish ladder with gaboin. On Namdae-cheon 1,195 fishes of 24 species were collected. Amog these fishes 241 fishes of 9 species were anadromous fishes occupying 38% in species and 19% in number. On Osib-cheon 1,015 fishes of 24 species were collected. Among these fishes 240 fishes of 5 species were anadromous fishes occupying 21% in species and 24% in number. On Namdae-cheon the species number and auundance decreased gradually upstream. The poor structure of fishways seems to have worked as an obstacle to the upstream migration of fishes on Namdae-cheon. On Osib-cheon all the observed fish species except three -spined stickleback(Gasterosteus aculeatus aculeatus) which stay and spawn around downstream of river could migrate upstream. The good structure of fishways on this river is thought to have helped upstream fish migration.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.21-27
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• 2010

Immersed boundary lattice Boltzmann method (IBLBM) has been applied to simulate a turbulent flow over circular cylinder in a flow field effectively. Although IBLBM is very effective method to simulate the flow over a complex shape of obstacle in the flow field regardless of the constructed grids in the calculation domain, the results, however, become numerically unstable in high reynolds number flow. The most effective suggestion to archive the numerical stability in high Reynolds number flow is applying the multiple relaxation time (MRT) model instead of single relaxation time(SRT) model in the collision term of lattice Boltzmann equation. In the research MRT model for IBLBM was introduced and comparing the numerical results obtained by applying SRT and MRT. The hydraulic characteristic of cylinder in a flow field between two parallel plate at the range of $Re{\leqq}2000$represented and it is also compared the drag and lifting coefficients of the cylinder calculated by IBLBM with SRT and MRT model.

• Journal of computational fluids engineering
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• v.6 no.2
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• pp.22-31
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• 2001

The two-dimensional unsteady incompressible viscous flow behind rectangular bluff bodies between two parallel plates was analyzed numerically. The steady state flow and the vortex flow behind rectangular bluff bodies in the channel were investigated for two regimes i.e., the laminar(Re = 100, 300, 500) and the turbulent flows(Re = 10⁴∼10/sup 6/). The vortex shedding was generated by a physical disturbance(6%) numerically imposed at the rear of the bluff bodies for a short time. It was observed that the perturbed flow became periodic after a transient period. And in the case of unsteady inflow, the sinusoidal pulsatile flow was applied as the inlet condition in the turbulent flow of Reynolds number of 1.0×10/sup 5/. FLUENT code was employed to solve the problems. The power-law scheme was used to get stable linearized equations and the PISO algorithm was applied to finding the solution of them.

• Journal of Acupuncture Research
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• v.24 no.1
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• pp.99-110
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• 2007

Objectives : This study was performed to evaluate a recent status of acupunctural treatment in pediatric practice. Methods: 660,893 children, who visited HAMSOA oriental clinic from January 2004 to December 2005 was screened to decide the number treated with acupuncture, the diagnosis and the type of acupuncture. In addition, the questionnaire for clinician about acupuncture therapy was performed and analysed to understand their applications. Results: The number treated with acupuncture was 69,797, 10.56%. Classified with ages, 3 months and below was 729 (1.7%), 1 year - 3 months was 5,035 (11.80%), 2 year - 1 year was 6,875 (16.10%), 3 year - 2 year was 5,540 (12.98%), 6 year - 3 year was 12.636 (31.94%) and 6 year and above was 10,876 (25.48%). The most frequent diagnosis taken acupuncture was atopic dermatitis (14.93%) and the next was rhinitis (13.80%). The most frequent type of acupuncture was laser acupuncture. The clinicians answered questionnaire agreed that acupuncture therapy is effective for pediatric disease treatment and fear about acupuncture of young patients was the most important obstacle. Conclusion : The acupuncture therapy in pediatric practice is not so frequent treatment but in increasing stage. Futhermore, in-depth research about acupuncture therapy in pediatrics is demanded.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.80-85
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• 2021

This study is to analyze the structure of the networks of tourism marketing on Twitter, identifying the most prominent users, the flow of information about tourism marketing, and the interaction between the users posting tweets. This study employs NodeXL pro as a visualization software package for social network analysis. The number of vertices or nodes is 171, and the number of the unique edges or links is 128, but there are 101 edges with duplicates, so the total links are 229, which means that there are fewer Twitter accounts in the social network on tourism marketing, but they have a few close relationships by sharing information. The research can map the social network of communicators of tourism marketing using Twitter data. The network has a complicated pattern, including one independent network and some connected networks. Some mediators connect each network and can control the information flow of tourism marketing. More communicators are getting the information than the ones providing it, which means that there is likely to be the dependence of information among communicators that can cause an obstacle and distortion of the information flow system, especially in the independent network.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.493-498
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• 2009

Recently, the number of complex construction projects, such as high-density development and long-span mega structure construction, has been increasing globally. Therefore, the construction duration has become an even more important factor for success. Nevertheless, in domestic residential construction projects, it usually takes more time than twice as much as North American cases. The long construction duration causes a number of problems, for example growth of financial costs, fall in productivity, and weakness of competitiveness. If the framework construction duration can be shortened to 3 ~ 4 days, then it is also expected to complete the finish work of building in shorter duration, be led to reduce the entire construction duration, and eventually to save a great deal of indirect costs. For shortening the construction duration, previous researches pointed out that the development of simplified plan design should precedes. But, in reality, lack of experience of new design and innovative techniques tends to be the obstacle to wide adoption of the simplified plan design in construction fields. In this paper, a simplified structural plan design is proposed, and the construction cost is quantitatively compared between when traditional construction technique is applied to the traditional plan and when the duration-shortening key technique is applied to the developed plan.

• International Journal of High-Rise Buildings
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• v.12 no.4
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• pp.273-285
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• 2023

The commercial buildings greening can generate multiple benefits to achieve a sustainable building and business environment. However, a comprehensive systematic review of commercial buildings greening across multiple disciplines has yet to be reported. This study conducted a systematic analysis of 39 literature on commercial building greening from Web of Science over the past 19 years and utilized CiteSpace to visualize the academic evolution and trends in this field. Key findings were: 1) The number of publications in the past five years has increased, indicating that commercial building greening research has received widespread attention. 2) The large number of publications means that the research field of commercial building greening is relatively broad. 3) The study of commercial building greening has become a global participation and cooperation research topic. The top cooperating countries mainly come from the United States and Europe, while the differences in cooperation between institutions in developing countries are less significant. 4) The greening of commercial buildings is more related to research on behavioral activities. 5) The research on commercial building greening has developed from architecture and plants to interdisciplinary fields, including psychology, economics, and management. 6) The cost of commercial buildings greening is generally an obstacle to installation. This study provides specific references for stakeholders and plays a crucial role in determining the evolution of commercial building greening research and predicting future research needs and opportunities.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1888-1893
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• 2007

In this study, the microchannel plated heat exchanger were numerically studied for the enhancement of heat transfer in the channel configuration. Unit cold and hot fluid region with the microchannel were modeled and periodic boundary condition at the side wall was applied to continuously repeating geometry. The material of micro-structured plate is STS304 and working fluid is water. Triangular obstacles were placed in micro channel to enhance heat transfer. The performance of microchannel plated heat exchangers were numerically investigated with various obstacle configuration and Reynolds number under the parallel and counter flows. Heat transfer rate has increased about 18% compared with straight channel, but pressure drop also increased about 3.5 times. The main factor of increasing of pressure drop and heat transfer rate is considered that the momentum was lost to collide against obstacles, generation of secondary flow and boundary layer separation, wake and vortex forming phenomena.

• English Language & Literature Teaching
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• no.6
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• pp.75-88
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• 2000

There are many reasons why foreigners have difficulties learning English. In addition to the difference between English and the learner's grammar, the large number of irregularities found in English become another obstacle to learning English. Understanding the difference and the irregularities will help us not only have a good command of English but also teach English more effectively. Many irregular or alternating patterns, or even anomalies in Modern English are the results of historical changes. In this paper, I would like to focus on some of the irregular or alternating patterns found in different components of the grammar of English and to show how they can be accounted for historically. Through this study, I would like to show that the irregular patterns and anomalies in English were once regular and systematic, they have deviated from the regular patterns of the grammar as time has gone by, and they have survived in Modern English as irregular and alternating patterns. Many of the irregular or alternating patterns can be traced back by phonological, morphological and/or semantic changes in the history of English. Finally, by looking at language history, we can hold a more tolerant view on many anomalies present in English.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.227-230
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• 1997

In this paper, robot navigation experiments with a new navigation algorithm are carried out in real environments. The authors already proposed a reactive navigation algorithm for mobile robots using optimal via-point selection method. At each sampling time, a number of via-point candidates is constructed with various candidates of heading angles and velocities. The robot detects surrounding obstacles, and the proposed algorithm utilizes fuzzy multi-attribute decision making in selecting the optimal via-point the robot would proceed at next step. Fuzzy decision making allows the robot to choose the most qualified via-point even when the two navigation goals-obstacle avoidance and target point reaching-conflict each other. The experimental result shows the successful navigation can be achieved with the proposed navigation algorithm for real environments.