• Korean Journal of Community Nutrition
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• v.9 no.4
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• pp.464-471
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• 2004

For the purpose of developing ‘Web-Based Nutritional Education Program’, this study did instructional analysis, analysis of entry behaviors and learner characteristics to select instructional contents for nutritional education program for junior/senior high school students. Survey questionnaires were distributed from October 21, 2002 to October 26, 2002 to a total of 564 junior/senior high school students in Seoul. The total number of questionnaires collected and used in our study was 479, which is 84.9% of the total questionnaires distributed. As a result of the curriculum analysis of ‘Technology-Home economics’, subjects related with ‘food and nutrition’ in the 7$^{th}$ educational course study result, lessons including the contents of food and nutrition were ‘nutrition and meal of adolescent’ in 7th grade, ‘family meal management’ in 9th grade and ‘practice of home life’ in 10th grade. According to the curriculum analysis, ‘nutrition’ and ‘food’ were chosen for the superior subjects of nutrition education program and four subordinate subjects per superior one were developed. Then, entry behaviors and learner characteristics were analyzed： life characteristics, internet usage, anthropometrics data and nutritional knowledge. Students were interested in using computer and preferred passive activity to dynamic activity. According. to the analysis of internet usage, WBI for students should composed active parts such as game, moving image, immediate reply and follow-up bye-mail, bulletin board and com- munity activity. Students’ BMI were in normal range but they were lacked nutritional knowledge. We wrote performance objectives that were specific behavior skills to be learned, the conditions under which they must be performed and the criteria for successful performance. The next step for developing the WBI nutrition education program would be based on the results mentioned above.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.6
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• pp.478-486
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• 2017

In this paper, we propose an algorithm for the wideband beamforming in a conformal phased array antenna by compensating the errors. For the wideband beamforming, we used the True Time Delay(TTD), which was fabricated on the RF circuit board to obtain long delay lines. Beamforming errors in the conformal array antenna are the mutual coupling between the array elements, the dispersive error in the TTD circuit, and the quantization error by the digital control. We apply the compensation algorithm to the conformal phased array antenna of wideband 2~4 GHz, and verify the usefulness by comparing the results with the experiment results.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.245-252
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• 2003

We designed a silicon pressure sensor interface circuit with digital calibration capability. The interface circuit is composed of an analog section and a digital section. The analog section amplifies the weak signal from the sensor and the digital section handles the calibration function and communication function between the chip and outside microcontroller that controls the calibration. The digital section is composed of I2C serial interface, memory, trimming register and controller. The I2C serial interface is optimized to suit the need of on-chip silicon microsensor in terms of number of IO pins and silicon area. The major part of the design is to build a controller circuit that implements the optimized I2C protocol. The designed chip was fabricated through IDEC's MPW. We also made a test board and the test result showed that the chip performs the digital calibration function very well as expected.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1216-1223
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• 2014

Internet traffic is rapidly increasing due to the spread of personal smart devices and the demand for multimedia contents. When designing a large ship such as cruise, network architecture is also considered which supports various IT services in a maritime environment similar to the ground environment. In this paper, we consider wireless P2P (peer-to-peer) communication for efficient multimedia content sharing and propose novel handover scheme for efficient download service. The proposed handover method shows that it can improve the download symbol rates for handover in a wireless P2P system considering the signal strength and quality of peers as well. The proposed system is expected to provide efficient contents distribution and reliable communication in the ship-area-network (SAN).

• Journal of The Korean Association of Information Education
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• v.25 no.5
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• pp.673-681
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• 2021

This study is a case study of artificial intelligence education subjects in the graduate school of education. The main educational contents consisted of understanding and practice of machine learning, data analysis, actual artificial intelligence using Entries, artificial intelligence and physical computing. As a result of the survey on the educational effect after the application of the curriculum, it was found that the students preferred the use of the Entry AI block and the use of the Blacksmith board as a physical computing tool as the priority applied to the elementary education field. In addition, the data analysis area is effective in linking math data and graph education. As a physical computing tool, Husky Lens is useful for scalability by using image processing functions for self-driving car maker education. Suggestions for desirable AI education include training courses by level and reinforcement of data collection and analysis education.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.5
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• pp.376-383
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• 2022

The improved performance of computer parts, such as graphic card, CPU, and main board, has led to the need for power supplies with a high power output. The dynamic load profile rapidly changes the usage of power consumption depending on load operations, such as PC power and air conditioner. Under dynamic load profile conditions, power consumption can be classified into maximum, normal, and standby power. Several problems arise in the case of maximum power. Peak power is generated at the system power source in the maximum-power situation. Frequent generation of peak power can cause high-frequency problems and reduce the life of high-pressure parts (especially high-pressure capacitors). For example, when a plurality of PCs are used, system overload occurs due to peak power generation and causes problems, such as power failure and increase in electricity bills due to exceeded contract power. To solve this problem, a system peak power limit/compensation power circuit is proposed for a power supply under dynamic load profile conditions. The proposed circuit detects the system current to determine the power situation of the load. When the system current is higher than the set level, the circuit recognizes that the system current generates peak power and compensates for the load power through a converter using a super capacitor as the power source. Thus, the peak power of loads with a dynamic load profile is limited and compensated for, and problems, such as high-frequency issues, are solved. In addition, the life of high-pressure parts is increased.

• Journal of Drive and Control
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• v.20 no.2
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• pp.15-23
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• 2023

In this study, two-dimensional location of crops for auto weeding was detected using deep learning. To construct a dataset for soybean detection, an image-capturing system was developed using a mono camera and single-board computer and the system was mounted on a weeding robot to collect soybean images. A dataset was constructed by extracting RoI (region of interest) from the raw image and each sample was labeled with soybean and the background for classification learning. The deep learning model consisted of four convolutional layers and was trained with a weakly supervised learning method that can provide object localization only using image-level labeling. Localization of the soybean area can be visualized via CAM and the two-dimensional position of the soybean was estimated by clustering the pixels associated with the soybean area and transforming the pixel coordinates to world coordinates. The actual position, which is determined manually as pixel coordinates in the image was evaluated and performances were 6.6(X-axis), 5.1(Y-axis) and 1.2(X-axis), 2.2(Y-axis) for MSE and RMSE about world coordinates, respectively. From the results, we confirmed that the center position of the soybean area derived through deep learning was sufficient for use in automatic weeding systems.

• Journal of IKEEE
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• v.26 no.1
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• pp.10-18
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• 2022

Accurate SOC estimation is an important indicator of battery operation strategies, and many studies have been conducted. The simulation method which was mainly used in previous studies, is difficult to conduct real-time SOC estimation like real BMS environment. Therefore, this paper aims to implement a real-time battery SOC estimation embedded system and analyze problems that can arise during the verification process. In environment consisting of two Raspberry Pi boards, SOC estimation with the EKF uses data measured by the Simscape battery model. Considering that the operating characteristics of the battery vary depend on the temperature, the results were analyzed at various ambient temperatures. It was confirmed that accurate SOC estimation was performed even when offset fault and packet loss occurred due to communication or sensing problems. This paper proposes a guide for embedded system strategies that enable real-time SOC estimation with errors within 5%.

• Journal of The Korean Association of Information Education
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• v.9 no.2
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• pp.231-241
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• 2005

There are two main purposes in learning map in the subject of social studies in understanding the map itself and growing the ability of construing connection and situation and reasoning by applying the map. However, the map learning leans to understanding the map itself in existing materials. Although there is an interaction between learners and the context, there is hardly any interaction between learners or between teachers. Therefore, this paper designs and implements the web-based map learning system using the constructivism to make the cooperative study possible through the interaction and to be able to teach the map learning based on learners. The characteristics of the system suggested in this paper are as below. First, learners study the basic factors of the map by themselves and enable them to give feedbacks after the evaluation. Also, it embodies to evaluate the context of study as a multiple question after studying the whole thing. Second, the participation is induced by bringing the interests of learners based on the web and the interaction between teacher and learner as well as between learners is strengthened by the bulletin board and chatting function. Third, the study of utilizing map is embodied by means of applying the study model of solving problems and suggesting useful tasks.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.107-113
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• 1990

This study was attempted to develop a remote controllable speed sprayer in order to protect an operator from agricultural chemicals. For the purpose of remote controllable transmission was developed by using one chip microcomputer. The following results could be summarized in this study. 1. Remote controllable transmission developed had not made even a single mistake during the test performed 100 times repeat. Thus, it could that this machine was very accurate. 2. One chip microcomputer was made by machine language and its was with in 3 sec's which was the same as human did. 3. One chip microcomputer which was used in the experiment could be widely used to automation of agricultural machinery, since it is smaller and chiper than any other similar ones such as personal computer, lap tap, one board computer. 4. Since, farm tractor has the same type of transmission as this system, it also could be adapted to farm tractors. 5. In this experiment, transmission lever was remote controll were designed to operate simultaneously. Thus, this system developed was more complicate than conventional system. However, by removing this transmission lever and by mounting the remote controll system at the speed sprayer, it would be higher and easier to handle than the conventional one.