• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.49-60
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• 2019

With the appearance of self-driving cars and electric cars, the automobile industry is rapidly changing. In the midst of these changes, HMI studies are becoming more important as to how the driver obtains safety and convenience with controlling the vehicle. This study sought to understand how automobile manufacturers understand the driving situation, and how they define and limit driver interaction. For this, prior studies about HMI were reviewed and 15 participants performed an on-road study to drive vehicles from five manufacturers with using their interfaces. The results of the study confirmed that buttons and switches that are easily controlled by the user while driving were different from manufacturer to manufacturer. And there are some buttons that are more intensively controlled and others that are difficult to control while driving. It was able to derive 'selection and concentration' from Audi's vehicle, 'optimization of the driving ' from BMW's, 'simple and minimize' from Benz's vehicle, 'remove the manual distraction' from the vehicle of Lexus, and 'visual stability' from KIA's vehicle as the distinctive keywords for the HMI. This shows that each manufacturer has a different definition and interpretation of the driver's driving control area. This study has a distinct value in that it has identified the characteristics of vehicle-specific HMI in actual driving conditions, which is not apparent in appearance. It is expected that this research approach can be useful to see differences in interaction through actual driving despite changes in driving environment such as vehicle platooning and self-driving technology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.467-478
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• 2019

This paper describes the development and measurement results of a wide-band planar active phase array antenna system for an electronic warfare jamming transmitter. The system is designed as an $8{\times}8$ triangular lattice array using a $45^{\circ}$ slant wide-band antenna. The 64-element transmission channel is composed of a wide-band gallium nitride(GaN) solid state power amplifier and a gallium arsenide(GaAs) multi-function core chip(MFC). Each GaAs MFC includes a true-time delay circuit to avoid a wide-band beam squint, a digital attenuator, and a GaAs drive amplifier to electronically steer the transmitted beam over a ${\pm}45^{\circ}$ azimuth angle and ${\pm}25^{\circ}$ elevation angle scan. Measurement of the transmitted beam pattern is conducted using a near-field measurement facility. The EIRP of the designed system, which is 9.8 dB more than the target EIRP performance(P), and the ${\pm}45^{\circ}$ azimuth and ${\pm}25^{\circ}$ elevation beam steering fulfill the desired specifications.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.25-31
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• 2019

This study Dasan Jeong Yak-yong, great writings, "Mokminsimso" and " Kyoungseyupyo"argued for reform of Dasan Jeong Yak-yong's tax law is a series of Surtax that have been included in or not in the law and have aggravated the tax burden on the people. Dasan Jeong Yak-yong's reform drive for the tax law did not end with a desk discussion, but went so far as to scrutinize the tax data in Gangjin, Jeolla-do, where he was in exile, and present various measures to abolish taxes and improve them in "Mokminsimso" and "Kyoungseyupyo". Based on the details of the tax laws for Dasan Jeong Yak-yong, "Mokminsimso" and "Kyoungseyupyo" this study reviewed the tax data and related prior research that Dasan Jeong Yak-yong investigated during his exile in Jeolla-do, The method of collection of various Surtax and the definition of tax amount and character of the Joseon Dynasty, which were insufficient in the preceding study, was modified and supplemented. and further summarized various Surtax that were not mentioned in the preceding study. In addition, similar and opposite Surtax found in the review process of this study were compared in the text. also, various Surtax collected from the Min-go that increased the tax burden of the people at that time were summarized.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.181-193
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• 2019

The regional economy growth of Jeju has seen higher than national growth since 2011 by the establishment of Jeju Special Self-Governing Province and the increase of incoming population, but its economic growth has slowed after 2016. This study conducted the dynamic shift-share analysis using the production and employees of each industry from 2010 to 2016, targeting Jeju with many factors of regional economic change. In the results of empirical analysis, the regional economy of Jeju was not the industrial structure depending on the national growth, but the industrial structure by the competitiveness and industrial structure of Jeju region. The industries having positive(+) effects of industrial mix effect and competitive effect on the production and the number of employees were the electricity/gas/heavy equipments & waterworks, construction, accommodation & restaurants, and service industry. These industries have positive effects on the regional industry of Jeju. The above-mentioned industries are not only more likely to grow than other regions, but also to drive the local economy of Jeju. In order for these industries to continuously contribute to the regional economy of Jeju, it would be necessary to have the policy/institutional support in the long-term perspective.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.217-225
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• 2019

The aim of this study was determine to effect of shaft length and physical condition on golf driving performance(head speed, distance and direction). A range of drivers with length between 44 inch, 45 inch and 46 inch limit imposed by R&A rules limited were assembled and evaluated. Club head speed and drive distance and accuracy were determined three category 27 PGA pro golfer (handicaps 0, and height $170cm{\geq}171-175{\geq}175-180cm$) who golf performance. As a results follow : Head speed was significantly difference with 44, 45 between 46inch(p<.01). Distance was significantly difference with 44 between 46inch(p<.05). And direction was significantly difference with 44, 45inch between 46inch(p<.05). Head speed according to height was general similarity among shaft length in 170cm, 171-175cm. Distance were general similarity among shaft length in 170cm, and significantly difference with 44inch between 46inch in 171-175cm(p<.01), and significantly difference with 45inch between 46inch in 176-180cm(p<.05). Direction were significantly difference with 44inch between 46inch in 170cm(p<.05), but do not significantly difference with 44inch between 46inch in 176-180cm, 176-180cm. These results show that shaft length and height can affect head speed, distance and direction.

• Journal of Practical Engineering Education
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• v.10 no.1
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• pp.17-24
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• 2018

Through the design and production of works for the third semester as a major unit, It is proposed the process of satisfying the graduation standards with the design and production process of the drone which can be applied to various mobile environments. Using the shape of Ring Propeller, it is made to be able to play both the role of generating lift as a propeller and the role of a wheel that touches the ground through the surface of the rim. In addition, the Servo Motor is used to convert the drive shaft of the motor to the correct angle according to the command. Then, based on the idea, the 3D printing is implemented to confirm the result of the configuration, and the circuit for driving the propulsion is designed and manufactured. As a result, the conversion of the desired propulsion system during air navigation and operation failed due to the weight increase of the propellant. It is confirmed that the size of the thrust and the tolerance limit of the ring propeller are the errors. Through these processes, it has been recognized to have experience of creative thinking and cooperation through engineering approach and comprehensive design, and confirmed to satisfy the graduation criteria by writing an engineering paper on the result.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.423-430
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• 2019

The convergence of the automotive industry and the ICT technology can be broadly divided into the commercial service sector and the Cooperative-ITS (C-ITS) service sector. The C-ITS service sector is using V2X communication technology as a field that aims to provide safer transportation, more green and efficient transportation, and more predictable and productive mobility. The recent convergence of self-driving cars and connected cars requires high data rates, low transmission delays, and low transmission error rates. Interest in comparison of performance between WAVE and C-V2X (LTE-V2X, 5G-V2X) has been amplified and application services by communication technology are being studied. In this paper, we design the application performance evaluation method of Hybrid V2X communication system and confirm that the decrease of packet error rate (PER) performance is caused by the increase of communication distance, not the vehicle speed.

• Communications of Mathematical Education
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• v.35 no.1
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• pp.75-96
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• 2021

This study aims to drive the implications for the structure of mathematics curriculum documents in Korea, exploring the coherence in the documental structure of the IB DP mathematics curriculum, which is gaining international attention. The documents of the IB DP mathematics curriculum were analyzed based on the coherence of external and internal structures. First, the curriculum was consistently described by subject and topic, presenting the table of contents and structure of the documents in the same format. Second, the descriptions of the curriculum between subjects and within the subjects were consistent through the same composition of the subject and assessment methods, the presentation of big ideas, and 'Guidance, clarification and syllabus links'. Third, in 'Connections', the curriculum documents were described with coherence through linking with other subjects by describing the connection plan with the real-world contexts, other subjects, and the 'Theory of Knowledge' in the IB curriculum. Based on these findings and implications for the concreteness and consistency of the components in mathematics curriculum documents, we propose the coherence between the presentation of subject areas and assessment methods of the revised curriculum, and the implementation of coherence in documental structure through links with other subjects.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.207-213
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• 2019

The fuel-cut coast-down driving mode is activated when the acceleration pedal is released with transmission gear engaged, and it's a default function for electronic-controlled engine of vehicles. The fuel economy becomes better because fuel injection stops during fuel-cut driving mode. A fuel-cut detection method is suggested in the study and it's based on the speed, acceleration and road gradient data from GPS sensor. It detects fuel-cut driving mode by comparing calculated acceleration and realtime acceleration value. The one is estimated with driving resistance in the condition of fuel-cut driving and the other is from GPS sensor. The detection accuracy is about 80% when the method is verified with road driving data. The result is estimated with 9,600 data set of vehicle speed, acceleration, fuel consumption and road gradient from test driving on the road of 12km during 16 minutes, and the road slope is rather high. It's easy to detect fuel-cut without injector signal obtained by connecting wire. The detection error is from the fact that the variation range of speed, acceleration and road gradient data, used for road resistance force, is larger than the value of fuel consumption data.