• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.201-206
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• 2010

A project for construction of Korea Geodetic VLBI has officially started in Oct. 2008. The construction of all system will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room where an H-maser frequency standard is located is in a building separated from an antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with diminishing the effect of path length variations. KVG's round-trip system is designed not only available to use either metal or optical fiber cables, but also available to measure path length variations directly by using K5/VSSP32 sampler. We will present principle of round-trip system and the new type of round trip system for KVG.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.14-23
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• 2007

The purpose of this study was to investigate beginning earth science teachers' perceptions about Learning in Geologic Field Trip. The hundred and sixteen high school earth science teachers who were in the training for their promotion answered the questionnaire of Learning in Geologic Field Trip. It was divided into five parts: needs and educational values, teachers' experiences and their difficulties, and desirable teaching methods of Learning in Geologic Field Trip. Results indicated that the participants perceived Learning in Geologic Field Trip important in earth science education and responded positively to the educational values of Learning in Geologic Field Trip. Most of the beginning teachers had experience of geologic field trip, but did not learn how to teach it to their students during the geologic field trip in the pre-service training program. It was shown that only a few teachers had experience of geologic field trip and of teaching students in the outdoor of geologic fields after they became a classroom teacher. Most of the participants perceived that teaching students about the geologic field trip is difficult because of lack of their experience. In order to overcome the difficulty, teachers suggested that they need to learn how to teach the geologic field trip to students through their in-service training. leachers suggested that a desirable teaching method of the geologic field trip is to provide teachers with a teacher's manual including geological explanation and information about field trip sites before their visit so that they can scaffold it and facilitate the students' cooperative group activity during the field trip. As a follow up activity, the participants agreed that the presentation and discussion about the results should concur.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.12
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• pp.537-546
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• 2014

The purpose of this study is to develope an algorithm which generates trip plans based on rating points of travel app users and travel experts to help potential travellers experience their desired destinations in advance. This algorithm uses the above rating points and the gradually created hierarchy to generate the most preferred and efficient trip courses. Users can go through video clips or panoramic VR videos of the actual destinations from their trip plans generated by the algorithm which may add excitement to their actual trips. With our heuristic methods, the more users input their ratings, the better trip plans can be generated. This algorithm has been tested on android OS and proven efficient in generating trip plans. This research introduces a way to experience travel destinations with panoramic VR video and proposes the algorithm which generates trip plans based on users' ratings. It is expected to be useful for travellers' trip planning and to contribute growth in the travel market.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.28-38
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• 2019

The smart card data stores the transit usage records of individual passengers. By using this, it is possible to analyze the traffic demand by station and time. However, since the purpose of the trip is not recorded in the smart card data, the demand for each purpose such as commuting, school, and leisure is estimated based on the survey data. Since survey data includes only some samples, it is difficult to predict public transport demand for each purpose close to the complete enumeration survey. In this study, we estimates the purposes of trip for individual passengers using the smart card data corresponding to the complete enumeration survey of public transportation. We estimated trip purposes such as commute, school(university) considering frequency of O-D, duration, and departure time of a passenger. Based on this, the passengers are classified as workers and university students. In order to verify our methodology, we compared the estimation results of our study with the patterns of the survey data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.55-70
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• 2018

Recently, as shared transportation services has expanded, integrated mobility services that link personal transportation and public transportation are paid attention. To do this, it is necessary to analyze trip mode chaining behavior. This study analyzed the characteristics of the trip mode chaining behavior using the 2010 travel diary survey in Seoul, and analyzed factors to affect mode choice of trip chaining through the multinomial logit model. The transportation means were classified into passenger cars, city buses, intercity buses, railways, taxis, and others, and 25 trip mode chaining types were identified. Among them, the trip share connected between city bus and railways was the highest. It was also found that the trip mode chaining occurred mainly at commuting and in the morning and afternoon peak. According to the model results, the mode choice of trip chaining is significantly influenced by individual attributes (sex and age), household attributes (car ownership and income), trip attributes (trip purpose, trip time and trip length), and arrival area attributes (number of subway lines and bus lines, ratio of commercial area, land use mix and central region).

• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.95-105
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• 2000

The Purpose of this study is to present a new Trip Generation Model using Backpropagation Neural Networks. For this purpose, it is compared the performance between existing linear/nonlinear Regression models and a new TriP Generation model using Neural Networks. The study was performed according to the below. First, it is analyzed the limits of conventional Regression models, next Proved the superiority of Neural Networks model in theoretical and empirical aspects, and lastly Presented a new approach of Trip Generation methodology. The results show that Backpropagation Neural Networks model is predominant in estimation and Prediction comparable to Regression analysis. Such results mean the possibility of Neural Networks\` application in Trip Generation modeling. Specially under the circumstances of the chancing transportation situations and unstable transportation on vironments, its application in transportation fields will be extended.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.66-70
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• 2001

The purpose of this paper is to investigate the characteristics of springback for the U-bending of steel sheets for automotive body panels. This study presents the experimental and analytical approach for the two kind of steel sheets, namely SCP1 and TRIP(Transformation-induced plasticity), the newly developed high strength steel. The adopted thicknesses are 0.8, 1.2 and 1.6 mm for SCP1, and 1.0 mm for TRIP. The punch profile radii are designed in 3, 6, 9, 12, and 15 mm. As results, the springgo aspect could be observed experimently in the small punch profile radius. The degree of springback for TRIP sheets was more than the SCP1 sheets.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.317-326
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• 2014

Slips and falls are associated with many public injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. The primary purpose of the present study is to determine if, and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the regulations in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.576-584
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• 2017

Traffic demand prediction result is a primary factor for decision making such as the traffic planning and operation. The existing traffic demand prediction 4-step model only covers the trip between the origin and the destination, and not the demand followed by the accessibility improvement, due to the characteristic of this model. Therefore, the purpose of this research is to improve the limitations of the existing model by developing the inter-city trip generation and trip distribution model with more accessibility. After calculating of the trip generation and trip distribution model with more accessibility, the sign of the accessibility coefficient was positive. Commuting was the most insensitive indicator, affected by external factors among the other trip purposes. The leisure trip was the most sensitive, affected by the trip fee. According to the result of comparison with each of estimated model and observational data, it was certain that the reliability and assumption of the model have been improved by discovering the reduced weighted average error rate, Root Mean Square Error (RMSE) and total error through the model with more accessibility compared with the existing one.

• Journal of Korean Elementary Science Education
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• v.29 no.4
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• pp.484-495
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• 2010

The purpose of this study was to investigate changes in geological contents knowledge and self-confidence before and after the geological field trips. Fifty seven undergraduate students at a national university of education participated in this study. The questionnaires were developed by the researcher to serve the purpose. Findings were as follows. First, before and after the geological field trip, there was no significant difference in changes of geological content knowledge (p<.05). However, participants' self-confidence about the geological field trip changed significantly (p<.01). Second, there were no significant differences in changes of both variables in terms of gender (p<.05). And in this study, participants were grouped into two: science track that selected science areas and non-science track with social study selected in the college scholastic ability test. There were also no significant differences in changes of geological contents knowledge and self-confidence in terms of science or non-science track (p<.05). Third, in terms of the geological content knowledge, 24 pre-service teachers showed an increase, 12 students unchanged, and the 21 participants decreased. In contrast, per participants' self-confidence about the geological field trip, fifty three students indicated an increase with only one participant unchanged, and three preservice teachers decreased on the score. Finally, after the geological field trip, participants' comments indicated that they could feel the mystery of nature with the mind of a great experience. As a result, data showed that pre-service teachers became interested in geology, and motivated more in learning geological area than ever.