• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.105-105
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• 2021

본 연구에서는 2차원 비선형 천수모형과 수심평균된 스칼라 이송모형을 해석하는 수치모형에 대해 기술하였다. 수치모형의 정확성을 보장함과 동시에 안정성을 높이기 위해 유한체적법, 플럭스 재구성 및 minmod 제한자를 사용하였다. 비선형 천수방정식의 이송항과 바닥 경사항은 계산된 수심의 양수 보존과 흐름의 정상 상태를 보장하기 위한 second order well-balanced positivity preserving central-upwind method를 이용하여 수치적으로 이산화되었다. 마찬가지로, 이송-확산 방정식 내 이송항은 동일한 2차 풍상차분법을 통해 수치적으로 풀이하였다. 격자점 경계면에서의 불연속으로 인한 수치진동을 방지하기 위해 이송항의 계산에 포함된 보존항의 차이로 인해 발생하는 스칼라의 수치확산을 최소화하기 위해 무차원의 비소산함수를 도입하였다. 또한, 확산항은 유한차분법을 이용하여 이산화하였다. 제안된 수치모형은 시간미분항의 계산을 위해 오일러 기법을 적용하여 계산된 수심 및 스칼라의 양수 보존여부와 함께 정지된 흐름의 정상 상태의 보존여부를 확인하였다. 제안된 수치모형의 해석 정확성을 평가하기 위해 1, 2차원 공간 내 다양한 흐름 조건에서의 해석해를 이용한 3개의 벤치마크 테스트를 수행하였다. 평균 제곱근 오차(Root Mean Squared Error, RMSE)를 산정하여 수치모형의 성능을 정량적으로 평가하였으며, 비소산함수를 적용함에 따라 스칼라의 수치확산이 감소하게 되었음을 확인하였다. 또한, 세 차례의 벤치마크 테스트 결과는 공통적으로 수치모형에 의해 계산된 결과값이 비소산함수를 고려함에 따라 해석해와 잘 일치함을 확인하였다.

• Particle and aerosol research
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• v.6 no.3
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• pp.107-121
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• 2010

The number of nanotechnology based consumer products are growing rapidly. Thus, the customer likely to be exposed to such products continues to increase as the applications expand. This article describes the international and Korea's policies on the EHS(Environment, Safety and Health) issues of nanotechnologies. The strategic plan and coordination of OECD and ISO were summarized. This article also examines several new findings of Korean researchers as well as current and future challenges in the aerosol application study of EHS issues on the nanotechnologies.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.85-96
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• 1986

From the two differently located orchards (even-site with adult tree and slope-site with young tree), weed emergence and the effect of various orchard herbicides on them were comparatively experimented. Weed emergence was assessed in emergence frequency, biomass, relative frequency, and herbicide responses were checked with the variarions in the above weed emergence characters and the weeding values. Herbicides applied were paraquat, glyphosate, oxyfluorfen, napropamide and ustinex using the recommended rates, respectively. Weeds emerged were 7 life-forms, 23 families and 45 species. Among other families, weeds Umbelliferae, Commelinaceae, Gramineae and Polygonaceae couldn't classified in any similarly correlated cluster. However, according to "1-Q mode cluster analysis" of each herbicide performances, "paraquat or glyphosate" with "napropamide or oxyfluorfen" were selected as the most unrelated herbicide pairs expecting the best combination value in mixture model, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.1 s.55
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• pp.53-58
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• 2006

Agrimonia pilosa Ledeb. is a perennial plant, which naturally habitats in whole area of Korea, and where it is popularly used for the traditional remedies. In the present study, A. pilosa Ledeb. extract was prepared to determine the anti-acne effects and application possibility as a cosmetic resource. A pilosa Ledeb. was extracted with methanol and its anti-acne effect against Propionibacterium acnes was investigated via minimum inhibitory concentration (MIC) and paper disk diffusion method. The MIC of A. pilosa Ledeb. extract and triclosan was 0.05 mg/mL and 0.04 mg/mL, respectively. This implies that A. pilosa Ledeb. extract nay be an efficient anti-acne ingredient for cosmetics, considering that it is a crude extract. The paper disk diffusion assay showed that its anti-acne effect was similar to that of triclosan. Furthermore, A. pilosa Ledeb. extract effectively inhibited the growth of several aerobic microorganisms including Staphylococcus aureus. Finally, we examine the stability of the extract to temperature and pH. The extract was very stable to high temperatures ($70{\sim}121^{\circ}C$) and to pH ($pH 2{\sim}11$), suggesting its utilization for cosmetics.

• (The) Research of the performance art and culture
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• no.42
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• pp.257-290
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• 2021

The Wonju Nongyo (agricultural work song) is geographically classified as eastern minyo (folk song) which has many distinctive, regional features such as tunes, forms and the use of a melodic line. There has been growing attention to the transmission value of the nongyo including the Wonju Eorirang of the Wonju Origol Nongyo and its region of origin. The Wonju Nongyo is of great value and worthy of preservation in the western part of Gangwon Province. For this reason, it seems fairer to say that a focus should be directed towards establishing the identity of the song and increasing the contextualisation of transmission. At the same time, the preservation association's efforts in passing the traditional song down and education activities fairly deserve equal attention. In addition to the way the folk songs are handed down, a discussion on the facilitation of their use will be required. An in-depth discussion about the restoration and use of the song will be encouraged in a multifaceted manner. Unfortunately, few of the previous literatures on nongyo has gone so far as to investigate Arirang as a separate research topic. In fact, the Wonju Origol Nongyo should be viewed as an intangible cultural asset that paved the way for performance artistry of the Korean agricultural work songs to be seen at a national folk art festival. From the perspective of regional characteristics (traditionally termed "tori"), the Wonju Eorirang represents the cultural value of the manners and customs of our locals which constitute unwritten and neglected literary property and musicality of the song. Particularly, a more attention should be paid to making a record of woodcutters and diversity of farmers' small cooperative groups. The existence of the Wonju Eorirang indicates that the melodies to which the song are sung in Nongyo are of infinite variety. A minyo-singer unfolds various journeys of life through various modes and structure of epic chants, ranging from first encounter, love to marriage, realistic problems to relationship with husband's family and death. The epic chant of the Wonju Origol Nongyo contains a rich variety of regional sentiments about life. In particular, the epic chants of the Galtteukgisor and Ssoeltteukgisori are a genius example of sexual satire and a sense of humor. In the past, the agricultural work songs were rhythmic songs served to synchronize physical movements in groups, coordinating tasks in upland farming and rice paddy with the usage of catchy, repetitive verses easy to pass down. The Wonju Origol Nongyo is a precursor of the work songs which took the farming activities a notch higher to be part of the excitement and festivals. In the context of transmission, a festival serves to demonstrate the value of history and life. The value of the Wonju Eorirang should be appreciated and a concerted effort should be made to find a way to facilitate the transmission of the folk song. A folk-singer is a traditional oral poet and a storyteller of minyo and the forms and species of melody solely depend on the signer. The combination of performance and witticism is shown by the singer freely expressing himself. The Origol Nongyo symbolizes ethnic arts cleverly combining playful effects such as tune, rhythm and old agricultural work of the region. It is to be hoped that much of the efforts is directed to designating such folk songs as the archetype of a cultural heritage. In terms of the foundation on which the folk songs are transmitted, the usage(Performance Content) of a community would be an alternative.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.551-554
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• 2006

Research Institutes of Government has produced various information about research, seminar, recent research trend, and so on. This information flows into project management organization and institute management organization. It is necessary to connect information systems of these organizations and institutes. The existing systems connect with self-defined protocol between the organizations and the institutes or HTML parsing method. but, these methods have many drawback for expanding and changing problem. This paper designs and implements science and technology information connection system using RSS.

• Journal of Labour Economics
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• v.29 no.1
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• pp.75-98
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• 2006

This study shows a theoretical model, based on transaction cost theory, for the choice of alternative work arrangement, Suppose that standard labor contract (permanent and full-time) is a typical labor contract of within-organization transaction and alternative labor contracts of variety are in the spectrum between market and within-organization transaction, the type and size of the market transaction cost for a specific labor would determine the appropriate labor contract. Firm-specificity and level of skill, scope and uncertainty of tasks, and duration of contract are the major determinants of transaction cost which, in turn, determines the type of labor contract. This theoretical model implies that there will be occupational segregation between standard and alternative work arrangements and that the legal regulations for protecting employment and wage of non-standard workers might not be so effective as expected.

• The Korean Journal of Mycology
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• v.43 no.2
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• pp.92-98
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• 2015

Hydrocharis dubia Backer and Salvinia natans All. were sampled from the Junam and Dongpan reservoirs, representative freshwater wetlands of Korea. A total of 19 endophytic fungal strains were isolated from hydrophytes native to the Junam wetlands and 5 strains were isolated from the Dongpan wetlands. Depending on phylogenetic analysis based on internal transcribed spacer (ITS) region, strains from Junam belonged to 11 genera and from Dongpan belonged to 5 genera. Fusarium, Phoma and Talaromyces were commonly distributed genera from two wetlands. The fungal diversity index showed clear differences between each wetlands or each host hydrophyte. Above all, the highest diversity value was observed from Salvinia natans All., which have been reported as promising biological resources as eutrophication controller in environmental ecology.

• Journal of KIISE:Software and Applications
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• v.31 no.5
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• pp.570-576
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• 2004

It is very difficult to efficiently solve a large-scaled maximal covering problem(MCP) by a genetic algorithm. In this paper, we present new crossover and mutation operators specially designed for genetic algorithms to solve large-scaled MCPs efficiently. We also introduce a novel genetic algorithm employing unexpressed genes. Unexpressed genes are the genes which are not expressed and thus do not affect the evaluation of the individuals. These genes play the role of reserving information susceptible to be lost by the application of genetic operations but is suspected to be potentially useful in later generations. The genetic algorithm employing unexpressed genes enjoys the advantage of being able to maintain diversity of the population and thus can search more efficiently to solve large-scaled MCPs. Experiments with large-scaled real MCP data has shown that our genetic algorithm employing unexpressed genes significantly outperforms tabu search which is one of the popularly used local neighborhood search algorithms for optimization.

• The Journal of Society for e-Business Studies
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• v.23 no.3
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• pp.51-64
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• 2018

Recently, the magnitude and frequency of the natural disaster have been increased, the damage has become severer. The importance of disaster response system to relieve the damage has arised continuously. This study has tried to develop the algorithm to solve the facility location and size problem in emergency logistics. A facility in the emergency logistics has various roles in victim care, casualty treatment, relief resource management and relief vehicle assistance. Moreover, the location of facility in emergency logistics has to consider the safety and reliability. To gather these information, information management system with IoT sensors are suggested. The location problem in this study also covers various features to response various demands in disaster. To solve this problem, this study suggested MIP based algorithm. Scenario based simulation experiments are conducted to verify the performance suggested algorithm.