• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.17-23
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• 2016

In the future network such as Internet of Things (IoT), the number of computing devices are expected to grow exponentially, and each of the things communicates with the others and acquires information by itself. Due to the growing interest in IoT applications, the broadcasting in Opportunistic ad-hoc networks such as Machine-to-Machine (M2M) is very important transmission strategy which allows fast data dissemination. In distributed networks for IoT, the energy efficiency of the nodes is a key factor in the network performance. In this paper, we propose a fuzzy logic based probabilistic multi-hop broadcast (FPMCAST) algorithm which statistically disseminates data accordingly to the remaining energy rate, the replication density rate of sending node, and the distance rate between sending and receiving nodes. In proposed FPMCAST, the inference engine is based the fuzzy rule base which is consists of 27 if-then rules. It maps input and output parameters to membership functions of input and output. The output of fuzzy system defines the fuzzy sets for rebroadcasting probability, and defuzzification is used to extract a numeric result from the fuzzy set. Here Center of Gravity (COG) method is used to defuzzify the fuzzy set. Then, the performance of FPMCAST is evaluated through a simulation study. From the simulation, we demonstrate that the proposed FPMCAST algorithm significantly outperforms flooding and gossiping algorithms. Specially, the FPMCAST algorithm has longer network lifetime because the residual energy of each node consumes evenly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.4
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• pp.355-363
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• 2007

The purpose of this study is to maximize the use of framework data by a method for updating road framework data using a economical, rapid, and accurate Vehicle-based kinematic survey to get the latest road data among "transportation framework data" which was built in 2003. We collected data using a Vehicle-based kinematic survey with DGPS (Differential Global Positioning System) in Daejeon and Pyeongtaek city and verified the accuracy of line and point features between surveying and previous results. The result showed that Daejeon city which is located near GPS CORS (Continuously Operating Reference Station)s and receive a signal well had lower errors than 1/5,000 digital base map, and Pyeongtaek city which is located far from the stations and receive a signal badly had errors beyond the limits. The study showed that postprocessing method or Total Station surveying should be used where signals cannot be detected well after analyzing a receiving rate from GPS CORSs, the stations of other organizations should be shared, and further studies are needed.

• Journal of Gifted/Talented Education
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• v.20 no.3
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• pp.921-946
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• 2010

The purpose of this study is to devise a model of career decision in the science-gifted by exploring factors of having influence upon career decision in the science-gifted undergraduates of our country, and by examining pattern and path of career decision. By suggesting a model of structure, which synthetically considered factors of parents (parental social support), school (stress of college life, adjustment to college life), and individual characteristics(problem solving ability, career decision-making self-efficacy, conviction for major selection)as for career decision in the science-gifted undergraduates through this study, the aim was to arrange the theoretical frame for career in the science-gifted undergraduates. The research subjects were 93(class of 2007~2009) students who completed education in 2002 and 2003 at the gifted education center affiliated with University, and 264 scholarship students(class of 2005-2008) by the President at home and abroad, who are receiving scholarship by being selected as a science scholarship student by the incumbent President. The measurement tools, which were used in this study for collecting data, are test of parental social support, test of problem-solving ability, test of stress in college life, test of adjustment to college life, test of efficacy in career decision, and test of having confidence in selecting a major. For statistical analysis of the collected data, SPSS Program and AMOS Program were used. As a result, the model showed a good fit to the present data in the science-gifted undergraduates, TLI=.928, CFI=.941, RMSEA=.059. It was confirmed to be a model that is accepted in the group of the science-gifted undergraduates. Also, hypotheses, which were established on the basis of a theoretical quest, could be known to have been all adopted except one path. The results of this study can be offered as basic data for developing program and implementing a system in order to broaden the width of understanding about career and to help the career decision in the science-gifted.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1007-1015
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• 2008

In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.753-760
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• 2018

Objective : We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs). Methods : We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans ($CK_{original}$) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at low-isodose levels (10-30% of prescription dose) for dose spillage. In each case, a modified CK plan ($CK_{modified}$) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared. Results : There were no differences in the conformity indices among the $CK_{original}$, $CK_{modified}$, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the $CK_{modified}$ plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the $CK_{original}$ plans (p<0.001), with no statistical differences in those volumes compared with GK plans (p=0.345). Conclusion : These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

• Journal of Radiation Protection and Research
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• v.44 no.1
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• pp.26-31
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• 2019

Background: Stereotactic ablative radiotherapy (SABR) plans in prostate cancer are compared and analyzed to investigate the low magnetic effect (0.35 T) on the dose distribution, with various dosimetric parameters according to low magnetic field. Materials and Methods: Twenty patients who received a 36.25 Gy in five fractions using the MR-IGRT system (ViewRay) were studied. For planning target volume (PTV), the point mean dose ($D_{mean}$), maximum dose ($D_{max}$), minimum dose ($D_{min}$) and volumes receiving 100% ($V_{100%}$), 95% ($V_{95%}$), and 90% ($V_{90%}$) of the total dose. For organs-at-risk (OARs), the differences compared using $D_{max}$, $V_{50%}$, $V_{80%}$, $V_{90%}$, and $V_{100%}$ of the rectum; $D_{max}$, $V_{50%}$, $V_{30Gy}$, $V_{100%}$ of the bladder; and $V_{30Gy}$ of both left and right femoral heads. For both the outer and inner shells near the skin, $D_{mean}$, $D_{min}$, and $D_{max}$ were compared. Results and Discussion: In PTV analysis, the maximum difference in volumes ($V_{100%}$, $V_{95%}$, and $V_{90%}$) according to low magnetic field was $0.54{\pm}0.63%$ in $V_{100%}$. For OAR, there was no significant difference of dose distribution on account of the low magnetic field. In results of the shells, although there were no noticeable differences in dose distribution, the average difference of dose distribution for the outer shell was $1.28{\pm}1.08Gy$ for $D_{max}$. Conclusion: In the PTV and OARs for prostate cancer, there are no statistically-significant differences between the plan calculated with and without a magnetic field. However, we confirm that the dose distribution significantly increases near the body shell when a magnetic field is applied.

• Trans-
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• v.11
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• pp.119-142
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• 2021

Video was a cultural practice based on image. The audience longs to experience new things, not everyday things through by video images. There are many components of the image, but among them, color, a visual representation, plays a big role. Since the advent of color films, color has constantly evolved as an important component of visual art and has become an important role in innovative visual art design. According to film history data, filmmakers were interested in color since the film was created in 1895, but in the early stages of film development, film colors were only black and white. Because these two colors no longer satisfy viewers, more natural colors began to emerge from the film as it was colored. However, with the development of historical paintings, the lack of artistic creation and the public's level increased, making people more active in using colors because simple reproduction of natural colors alone does not satisfy people. The colors in the video are both techniques of expression and can be understood by mind and thought. It is also an indication that colors do not just exist, but they work strongly on human psychology. Now people are so motivated by repetitive and unimportant information that they find that the human intuitive system simplifies the information they receive unconsciously that they have certain customs and characteristics when they see things. Color is part of the film language, or color language can express the film's ideological themes or portray vivid characters in the film, and people are receiving more intuitive messages. This study analyzed the basic color components of bisexual lighting, namely, pink, blue, and purple, and analyzed how human psychology is affected through color, combining the scenes from the video. The purpose of this paper is to explore what color language bisexual lighting is expressed using color properties in images and how bisexual lighting interacts with human psychology through color.

• (The)Study of the Eastern Classic
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• no.73
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• pp.415-444
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• 2018

This study was designed to analyze the delivery patterns of early(1900-1945) letters from the beginning of the postal service in order to examine the process of establishing the modern postal system after the constitution of the Postal Service(1884). In Chapter 2, we examined the 'change of the way letters are delivered', Chapter 3 is about the 'change of expression' and Chapter 4 is about 'double-faced of the post'. In the examination of aspects of changing the way letters were delivered, the phase of postal delivery by personal delivery to postal delivery were divided into three phases: [the period of personal delivery delivery] > [the coexistence period of personal delivery and postal deliveryy] > [the period of postal delivery]. In particular, it was interesting to see that the same sender and receiver mixed up postal delivery and personal delivery by the case in the second period. In addition, the functional differences between the express, telegram and particular post were found in the examination fo contents of the letter. In the examination of aspects of changing in expression, a change of common expression in 'greeting, ending, and receiving expressions' were confirmed. Also, it was confirmed that 'woo-pyeon' was not used as the basic term, but instead replaced with various terms, and that 'woo' was used independently and productively. In the double-faced aspects of post, there were disadvantages of the postal delivery such as 'discontent of the lost' and 'security of confidentiality', despite the advantages of 'economic, rapid, and long-distance delivery'. Because the disadvantage of postal delivery could be supplemented by personal delivery, postal delivery and personal delivery could coexist for a considerable period of time.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.232-243
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• 2021

This study analyzed how K-MOOC was used and identify the academic achievements in higher education. The participants who completed the survey questionnaire were composed of 379 students who were in curriculum-related extra-curriculum using K-MOOC. Results show that the participation rate in individual learning activities was high, thus indicating the activities were perceived positively. In addition, students perceived positively their academic achievements of receiving, valuing, and responding in affective area, as well as synthesis and evaluation of knowledge in cognitive area. Students were also satisfied that they had no psychological burden to the credit of the course and they could take a course from another college. By contrast, platform instability, too much online content, and tedious activities in the lessons were perceived negatively. Nonetheless, the group assessment results suggested that the students taking a course related to their major had further engagement in discussions, and their academic achievement was higher. Based on the foregoing findings, the study proposed developing a subject matter with various theme, utilization plans, interaction reinforcement, and quality management by supporting instructional design strategies in order to expand the use of K-MOOC both as a general education and a major curriculum. The results obtained in this study represent baseline data that may assist in the decision making for university system and operation plan.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.