• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.263-279
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• 2015

The introduction of real numbers is one of the most difficult steps in the teaching of school mathematics since the mathematical justification of the extension from rational to real numbers requires the completeness property. The author elucidated what questions about real numbers can be unanswered as the "institutional didactic void" in school mathematics defining real numbers as the union of the rational and irrational numbers. The pre-service teachers' explanations on the extension from rational to real numbers and the raison d'$\hat{e}$tre of arbitrary non-recurring decimals showed the superficial and fragmentary understanding of real numbers. Connecting school mathematics to university mathematics via the didactic void, the author discussed how pre-service teachers could break the illusion of transparency about the real number.

• Journal of the Korean Society for information Management
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• v.32 no.1
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• pp.109-134
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• 2015

In the Korean wave 3.0 age, it is needed to prepare how to globalize and hold Korean culture through development of various Korean wave culture contents from existing contents focused on media. The goal of this study is to establish the foundation for developing the various Korean wave culture contents as linking information about other culture contents as well as food culture by extending Korean culture contents service based on LOD. For this purpose, this study established and assorted the concept of food culture through the literature review and case study and analyzed the applicability of the services of food culture contents based on LOD. Futhermore, this study provides the basis on extension of Korean wave culture service and suggests the process of implementation of food culture LOD and service model.

• Journal of Agricultural Extension & Community Development
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• v.26 no.2
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• pp.99-111
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• 2019

This paper aims to analysize the regional disparity of rural life service. In other words, analyzing the spatial distribution of the single-households elderly and service accessibility to public transportation, and the relationship between them in rural. The results of this study are as follows. First, there is a high concentration of the single-households elderly in Gyeongsangbuk-do and Jeollanam-do, and the distribution of them shows a tendency to cluster locally. Second, the vulnerability area of public transportation are concentrated on the myeon area. Third, The above-average proportion of vulnerable single-households elderly in Gyeongsangbuk-do and Jeollanam-do are concentrated on the myeon area. This result show that there is a positive correlation and high values are concentrated. This paper is expected to contribute to the regional development projects and effective implementation of rural polices.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.218-228
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• 1999

This study was conducted to obtain the information on dry matter productivity in Angelica gigas Nakai for establishing the cultivation method. Cultivation methods such as direct seeding on Mar. 31, Apr. 15 and Apr. 30, and transplanting of $8^{\frac{1}{2}}$, 9, 12 months old seedling were investigated. There were similar tendencies in changes of agronomic characters for all cultivation methods. Dry weight started to increase from 120 DAS. Direct seedling showed vigorous growth for aerial part, whereas transplanting showed better underground part. The quadratic polynomial was suitable to dry weight of root after 120 DAS (or DAT) .Short growing time had higher RGR and NAR independent of cultivation method but Direct seeding on Mar. 31 and transplanting of 9 months old seedling had the highest CGRs. LAI was positively correlated with CGR, and CGR had the highest value as $6.74\g/m^2/day$ when LAI was 1.97. RGR and NAR increased as mean temperature was increased and showed the highest value around . The highest net production of leaf and petiole was obtained at 20 and$23^{\circ}C$, respectively.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.45-45
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• 2018

We had already reported the successful germination for green pods of purple lady's slipper orchid (Cypripedium macranthos Sw.). The green pod methods is to take immature seeds in green capsules, sterilize the capsule, and take out the sterile seeds. This method, however, needs very critical time of harvest. The critical time of seed harvest changes depending upon the species, condition of the specimen, and climatic influence, and the right time lies between 5 and 12 weeks after fertilization. In this study, the mature seeds were collected after 120-130 days with hand-polination of lady's slipper orchids. Mature seeds are usually dormant and it has to be overcome, either with hormone or storing the seeds near freezing for two or three months to break dormancy. The seeds were first surface sterilized with 70% ethanol and then transferred 1% NaOCl for 10-15 minutes, followed by rinses 3 times with sterilized distilled water. The cypripedium seeds consists of an embryo within a seed coat known as a testa. The testa is water repellent and the seed has a large air space between the embryo and testa so the seed tends to float on water. We had resolved the problems with vacuum pump to soak water into the testa before sterilization. The seeds were placed on liquid or agar solidified germination media. Cultures were incubated at $24{\pm}1^{\circ}C$ in dark. The seeds were germinated in 6-8 weeks in liquid suspension culture (germination percentage over 18%); however, the seeds on agar solidified media took more than 5 months to germinate and the germination percentage less than 5%. The most effective media for liquid culture was 1/4 strength Murashige and Skoog (MS) medium with 50 ml/l coconut water ($4brix^{\circ}$) at pH 5.8.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.51
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• pp.441-464
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• 2011

It is childhood yet in uTradeHub system practical use. According as company's necessity of cost-saving is increased according to trade terms aggravation such as uncertainty of international money market, commodities prices rise, necessity of e-trade practical use in company is increased. Use is inevitable by state that link with e-Nego and e-B/L service with related presentation e-L/C banks is not made. At the present users are doing specification only service this main point, and practical use activation through public information and marketing about service is needed situation because most of, companies which is not using service, do not know about existence availability of uTradeHub system, usage, availability. This study presented five such as early materialization of user center's link and integration, medium and small enterprises e-trade participation extension, utilization ratio raising through government's public information, e-trade cooperation business activation between the country, electronic documents standardization etc. by prompting competition about practical use of uTradeHub system.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.110-113
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• 1999

In this paper. we propose an adaptive handover scheme in wireless network The proposed handover scheme is a hybrid type of virtual path extension and rerouting. The proposed handover scheme chooses the virtual path management scheme according to the service QoS instead of the network topology which is used in the previous hybrid handover schemes. The proposed scheme supports the seamless service and small buffering during virtual path rerouting handover through the multicasting service. To evaluate the performance of the proposed scheme. we compute the number of signaling message used for handover and perform computer simulation. The simulation results show that the proposed scheme provides more efficiency in the handover delay and seamless service than the previous methods.

• Journal of Information Management
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• v.41 no.1
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• pp.1-22
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• 2010

The Korean government is pursuing the policy of broadening easy access to information by local residents and the range of public services provided to them. One of the most recent prominent examples is the evening circulation service offered by public libraries. In a sense of addressing issues facing the newly implemented service, this study aimed to present an improvement scheme on the basis of the results from analyzing the data such as background motivation, ways of publicity, service open time, service content, the present status of use of materials, satisfaction of users, and operating difficulties experienced, which were attained from the public libraries implementing the service as of June 2009 and the service users.

• Journal of Korean society of Dental Hygiene
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• v.15 no.6
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• pp.1107-1116
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• 2015

Objectives: The purpose of this study was to examine awareness and satisfaction toward health insurance coverage of scaling. Methods: A self-reported questionnaire was completed by 221 patients receiving scaling service from July to August, 2014. The informed consent was approved after the explanation of purpose of the study. The questionnaire consisted of general characteristics of the subjects, awareness toward health insurance coverage of scaling, scaling service covered by health insurance, and satisfaction with health insurance service. Results: Those recognizing the health insurance service extension accounted for 87.3 percent and 67.4 percent answered that the appropriate coverage age would be 20 years old. The recommendable frequency of scaling was once a year and this accounted for 49.3 percent. Fifty percent of the subjects thought health insurance coverage of scaling would be reasonable and 34.8 percent acquired the information from mass media. The most common service providers were dental hygienists and the length of service was from 20 to 30 minutes. The contents of service included scaling service, toothbrushing method, and oral care. The satisfaction was 4.39 points. Conclusions: The health insurance coverage of scaling will improve the oral health and quality of life in Korean adults. So the government should try to extend the scaling coverage by health insurance and the frequency of scaling.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.175-177
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• 2006

According to the recommendation of International Maritime Organization, the Ministry Of Maritime Affairs and Fisheries (MOMAF) of Korea provides the real time Differential Global Positioning System service using maritime radio beacon from 1999. Due to the benefit of DGPS service, the need of this system is increased from various user groups for acquiring the better accuracy and integrity. Therefore, MOMAF has extended their service to inland by installing the additional 6 DGPS stations. This nationwide DGPS service will be fully deployed at 2007. In addition to the extension of service area, MOMAF has a plan to upgrade their nationwide DGPS to High Accuracy Nationwide DGPS (HANDGPS). The planned HANDGPS service of Korea will be a kind of long range RTK or Wide Area RTK techniques to provide under 1m accuracy and start their service from 2009 using the various broadcasting and communication media like as radio beacon, Wibro, Digital Multimedia Broadcasting, High Speed Packet Data Access. The introduction of nationwide DGPS system of Korea and its evolution plan will be addressed in this paper. The research activities related with HANDGPS in Korea is also presented.