• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.509-516
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• 2009

The Stream Control Transmission Protocol(SCTP) is a reliable transport layer protocol that provides several features. Multihoming is the one of the features and allows an association(SCTP's term for a connection) between two endpoints to use multiple paths. One of the paths, called a primary path, is used for initial data transmission and in the case of retransmission an alternate path is used. SCTP's current retransmission policy attempts to improve the chance of success by sending all retransmissions to an alternate destination address. However, SCTP's current retransmission policy has been shown to actually degrade performance in many circumstances. It is because that, due to Karn's algorithm, successful retransmissions on the alternate path cannot be used to update RTT(Round-Trip Time) estimation for the alternate path. In this paper we propose a scheme to avoid such performance degradation. We utilize 2bits which is not used in the flag field of DATA and SACK chunks to disambiguate original transmissions from retransmissions and to keep RTT and RTO(Retransmission Time-Out) values more accurate.

• Journal of People, Plants, and Environment
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• v.23 no.2
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• pp.233-243
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• 2020

This study collects social big data used in various fields in the past 9 years and explains the patterns of major keywords of the arboretums and botanical gardens to use as the basic data to establish operational strategies for future arboretums and botanical gardens. A total of 6,245,278 cases of data were collected: 4,250,583 from blogs (68.1%), 1,843,677 from online cafes (29.5%), and 151,018 from knowledge search engine (2.4%). As a result of refining valid data, 1,223,162 cases were selected for analysis. We came up with keywords through big data, and used big data program Textom to derive keywords of arboretums and botanical gardens using text mining analysis. As a result, we identified keywords such as 'travel', 'picnic', 'children', 'festival', 'experience', 'Garden of Morning Calm', 'program', 'recreation forest', 'healing', and 'museum'. As a result of keyword analysis, we found that keywords such as 'healing', 'tree', 'experience', 'garden', and 'Garden of Morning Calm' received high public interest. We conducted word cloud analysis by extracting keywords with high frequency in total 6,245,278 titles on social media. The results showed that arboretums and botanical gardens were perceived as spaces for relaxation and leisure such as 'travel', 'picnic' and 'recreation', and that people had high interest in educational aspects with keywords such as 'experience' and 'field trip'. The demand for rest and leisure space, education, and things to see and enjoy in arboretums and botanical gardens increased than in the past. Therefore, there must be differentiation and specialization strategies such as plant collection strategies, exhibition planning and programs in establishing future operation strategies.

• 보존과학연구
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• s.26
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• pp.203-211
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• 2005

The National Research Institute of Cultural Heritage(NRICH) conducted the Asia Cooperation Programme in Conservation Science(ACPCS) to facilitate and promote the regional cooperation in the conservation of cultural heritage among Asian countries. This course was promoted to provide an opportunity to study and work together, also to share a knowledge and experience in conservation field. The target countries were from 17 Asian countries, and this year our selection committee selected 2 specialist in cultural heritage conservation field and selected persons had participated in the ACPCS course during three months. NRICH provided the round-trip airline tickets, overseas travel accident insurance and a living allowance to the course participants. And we requested programme announcement to Korean National Commission for UNESCO and Ministry of Foreign Affairs and Trade to progress favorably. This course period was three months from 29 August to 25 November, and the fields were conservation and restoration of tangible cultural heritage such as metal conservation, stone conservation, material analysis, DNA analysis, dating, biological control management of cultural heritage, environmental monitoring and so on.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1088-1090
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• 2001

In general, Power SCR(Silicon Controlled Rectifier) is most widely used in Power Plant as well as Industrial field. It has been controlled and operated according to its own control method. Especially, in case of Power plant, it plays a major role in AVR(Automatic Voltage Regulator) or electro chlorination control circuits. Generally, they used in Analog control system at above field. But each SCR current value is different because of load unbalance or switching characteristic variations, it may cause power plant unit trip or system disorder according to SCR element burn out or bad operating condition. Therefore, in this paper a development of 3 phase current balance control unit is described, it gets over the past analog control system limit, uses DSP(Digital signal processor) had high speed response, controls SCR gate firing angle for 3 phase current balance.

• Korean Journal of Health Education and Promotion
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• v.2 no.1
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• pp.113-121
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• 1984

How can the educator help learners to learn? The old way was to tell learners as much as possible, passing on the educator's knowledge. Now the educator acts as a helper. She will organise experiences which allow the learners to do health behaviors, she may utilize instructional materials, she may write downsome questions for a group of learners to discuss. In all these ways the teachers is helping learning. Some educators feel that they must do all the talking themselves. They feel that they are not really teaching the learners some new information, but this is quite wrong. In fact if a educatorgives a lecture and learners do not learn, then the educator is talking not teaching. So the devlopment of instructional materials is much needed to be a learner education. And the selection of materials may be very important for the level of maturity of the learners in interest, complexity of ideas, opportunity for self-identification, speed of learners' ability to observe and length of concentration. Author studied the several instructional materials which can be utilized in the field of dental health education and also studied their values, limitations and considerations when they are used. The learning activities are poster, puppet, model, mock-up, specimen, flannel board, chalk board, bulletin board, psychodrama, role play, field trip, exhibition, laboratory method.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.15-22
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• 2006

This study intends to raise the fire safety awareness level which the teachers have in infant schools. The results of the study are as follows. The early childhood teachers consider the fire safety awareness level of our society low, though their fire safety awareness level be above the average. The education program for the fire safety is mapped out and the teachers prefer an observation class and a field trip for the program in almost infant schools. The early childhood teachers have difficulty acquiring the knowledge for the field experience and work and getting teaching aids for the fire safety. Therefore the early childhood teachers extremely much desire teaching aids for infants to be developed and diffused.

• The International Journal of Costume Culture
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• v.6 no.1
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• pp.52-60
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• 2003

The purpose of this study was to examine the cases of the head family's costume culture and to apply them to field experience education of adolescent's home economics subject. To examine costume culture, women in the two head families in the Hampyeong area, Jeollanam-do were interviewed. The findings had unique shroud making and custom in the Mo's head family of Hampyeong. Also it was found that the eldest daughters-in-law of the Lee's of Hampyeong have horizontally exchanged the information of the head family's costume with village women of the same family. They have initiated their costume culture directly through their daughters and it had the great influence on after-ages. The Spot experience program for adolescent to experience the head family's costume culture and life culture consisted of four subjects:(l)Educating the head family's traditional living culture including etiquette training, (2)head family village walk, (3)experiencing the head family's clothes life including natural dyeing and sewing, and (4)a field trip of Hampyeong Local Life Culture Museum. For a model experience of the head family's costume and life culture, three families with middle and high schoolers participated in 8- hour experience learning program.

• Journal of the Korean association of regional geographers
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• v.10 no.4
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• pp.851-864
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• 2004

A coastal dune field, located at Kimnyong-Wolchung beach in Jejudo, Korea, extends alongshore for about 4 km, with dunes extending inland about 6 km. Detailed geomorphological analysis of the area was carried out by using areal photography and Landsat images. Samples were collected across two transects, and physical and chemical properties are analyzed to detect the variation of both properties depending on distance form the beach. Paleosol layers found during the field trip suggest that dune emplacement is episodic. Radiocarbon dates from nearby Hyupjae beach indicate that dunes have been formed during the late Holocene by the disturbance of calcareous materials.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.504-510
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• 2016

In general, a fault locator is installed in Sub-Station of AT(Auto-transformer) feeding system to estimate the fault location and to protect the Korean AT feeding system. Since the line impedance characteristic is different to normal 3-phase transmission line, we need particular modification factors, which can be calculated using fault location recording data, to estimate the accurate fault location. Up to recently, forcible ground test has been used to calculate the modification factors of the fault locator. However, large amount of current is occurred when the forcible ground test is performed, and this current affects to adjacent equipments. Therefore, we proposed a novel calculation method of modification factors, arbitrary trip test, using boosting current of the operating electric train. Through several field test, we confirmed that modification factors for fault locator can be easily calculated by using proposed method. Moreover, we verified the accuracy and stability of the proposed calculation method.

• Asia-Pacific Journal of Business
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• v.11 no.3
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• pp.261-271
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• 2020

Purpose - This study was to establish a unified tourism management class for university students based on Gangwon-do. Community based learning(CBL) was applied to provide a tangible and intangible resource of tourism resources the theoretical approaches and the actual experiences of the community. Design/methodology/approach - In order to design a unified tourism management module, this study applied qualitative research and quantitative research methods to collect information on the direction of the module. the study conducted in-depth interviews and then an online survey. Findings - According to the results of the study, the main parts should include necessity of unification, inter-Korean tourism, inter-Korean cooperation, inter-Korean economy, and international relations. Research implications or Originality - The overall composition of the unification tourism management class should be designed as the unification tourism management theory to acquire the subject knowledge, the field trip to the border area for experiential learning, and the assignment of the field study task to understand the community.