온라인 기반 아두이노 자동차 교수학습자료 개발 사례

이은상(Lee Eunsang) 학습자중심교과교육학회 2021 학습자중심교과교육연구 Vol.21 No.4

2020년 1학기, 우리나라는 코로나 19로 인해 각 학교급에서는 전면적인 온라인 수업 실시라는 초유의 사태를 경험하였다. 이에 많은 교수자가 온라인 수업 상황에 적응하지 못해 어려움을 겪었다. 특히 실습 활동이 주가 되는 교과의 경우, 온라인 상황에서 실습수업 자체가 이루어지기 어렵다는 점에서 타 교과보다 더 큰 어려움을 겪었다. 이러한 배경에는 온라인 상황에서 실습수업 사례가 많이 개발되지 않았기 때문이다. 이에 이 연구에서는 온라인 수업 기반 아두이노 자동차 만들기 교수학습자료를 개발하여 그 사례를 제시하고자 하였다. 이 연구에서는 Lee(2020b)의 저비용 마이크로컨트롤러 기반 교수학습 모형에 따라 아두이노 자동차의 차체를 개발하였고, 이 차체를 작동시키는 소스 코드를 제안하였다. 본 연구에서 제시한 교수학습자료의 개발 과정과 개발 결과물은 온라인상에서 실습수업을 진행하고자 하는 교수자들에게 유용한 참고 자료로 활용될 수 있을 것이다. During the first semester of 2020, Korea experienced an unprecedented situation where all schools were forced to conduct classes online due to Covid-19. As a result, many instructors had difficulty adapting to teaching classes online. Particularly, cases where the subjects were primarily taught using hands-on activities were more challenging than other subjects because it was difficult to conduct these classes in an entirely online situation. This is because there are few examples of hands-on lessons developed for use in online situations. Therefore, this study attempted to present an example by developing teaching and learning materials for “making Arduino car” based on online classes. In this study, an Arduino car’s body was developed according to Lee’s (2020b) low-cost microcontroller-based teaching and learning model. The proposed source code was used to operate the body. The development process and results of the teaching and learning materials presented in this study can be used as useful reference materials for instructors who want to conduct hands-on classes online.

A Study on the Proposal of the Behavioral Principles for the Training of Korea Coast Guard in the Pandemic Era10.22471/disaster.2022.7.2.52

Eunsang Lee(Eunsang Lee),Yeojin Lim(Yeojin Lim) J-INSTITUTE 2022 International Journal of Human & Disaster Vol.7 No.2

Purpose: This study proposes the Korea Coast Guard trainee behavior principle based on the value of the Korea Coast Guard in response to the Pandemic era. Through the proposed principle of action, we will provide philo-sophical standards for value judgment to members of the organization in various dilemma situations that Korea Coast Guard will face in the future. Recently, as a large number of young employees in various fields have been recruited in the Korea Coast Guard organizations, controversy has arisen due to the difference between the ex-isting policies and the expectations of the younger generation. This means that the organization should make more efforts to establish and share the priority of organizational value to its members. Method: The Korea Coast Guard organizations have unique cultural characteristics that have been formed with unique history. This characteristic of the members is to examine the result of the formation of philosophical value of the Korea Coast Guard organization, along with the value policy of the Korea Coast Guard focusing on the educational regulations applied to the current students by the Korea Coast Guard Education Academy. As a research method of this paper, I would like to examine the behavior style required by members according to the unique characteristics of the Korea Coast Guard organizations in phenomenological aspects. The media press releases were used to maintain objective grounds among various problems caused by the characteristics of the Korea Coast Guard, and the internal voice of the organization was referred to the internal bulletin board of the Korea Coast Guard Agency. Results: As a conclusion of this study, based on the review of the philosophy and educational goals of the Korea Coast Guard organization. The principle of action is proposed 'Five Promises of Korea Coast Guard Stu-dents'. The proposed principle of student behavior is organized so that it can be applied to actual education center life from the perspective of the student. The first regulation of the prize and penalty for the students can be seen as a behavior that is supported and trusted by the people through 'honorable life' that helps others. Second, it emphasizes that marine police will move toward a steady learning and effort as a guardian of the sea, along with the educational goal of 'trying to become an expert in the sea every moment' and prioritizing the expertise and practical skills. Third, the Coast Guard respect the human rights of the people who always keep their promises and do not follow injustice. Fourth, considering the spirit of public service value for the nation and the people that the result suitable for the public interest is more precious, overcoming the individual desire and discerning what is more suitable for the public interest is the value to be cultivated as a public official who serves the people afterward, and above all, it can be wary of the situation that falls into the individualistic tendency, forgetting that he is a 'serviceman of the people'. Fifth, the direction of the challenge spirit shown in the 'expert in the ocean' that 'I am willing to challenge and overcome for a better future' and the future-oriented image that pursues the world's best pursued by educational goals can be confirmed. Conclusion: As such, this research suggests that the fundamental cause for this dilemmatic situation is on the absence of the values based on the organizational philosophies, and it is necessary for the organization to set up the operational methods based on its philosophical values taking into account the principles of action which are appropriate to the task of KCG(Korea Coast Guard). Also, this research asserts that the operation based on philosophical grounds contributes to the sequential positivity such as ‘psychological stability of the members’ and ‘creating hard working environments’ this will also help its members’ learning process and enhance the orga

Stochastic Photon Emission from Nonblinking Upconversion Nanoparticles

Lee, Eunsang,Jung, Minhyuk,Han, Youngeun,Lee, Gibok,Shin, Kyujin,Lee, Hohjai,Lee, Kang Taek American Chemical Society 2017 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.121 No.38

<P>Because of their well-known optical properties, upconversion nanoparticles (UCNPs) are regarded as some of the most promising nano-materials for bioimaging, biosensors, and solar cells. The nonblinking nature of their upconversion emissions has been a particularly beneficial advantage for live-cell imaging. However, the origin of this unique property has never been seriously investigated. We report, for the first time, the observation of stochastic photon emission (SPEM) in core/shell UCNPs (NaYF4:Yb3+,Er3+/NaYF4) on the microsecond and nanosecond time scales, even under continuous irradiation at 980 nm. This SPEM was attributed to slow upconversion cycles. We consider that the conventionally reported, nonblinking nature of UCNP emissions can be attributed to the averaging of SPEMs from multiple Er3+ ions and the low temporal resolution of previous observation. The off-time distribution, which possesses kinetics information for the upconversion pathways, was well fitted to a single exponential indicating involvement of a single rate-determining step. The distinct behaviors of the green and red emissions confirm their different photophysical pathways.</P>

A Sustainable Method to Study Digital Logic Circuits Hands-on Activity Method Using Arduino

Eunsang Lee 한국실과교육연구학회 2021 實科敎育硏究 Vol.27 No.4

이 연구의 목적은 오픈 소스 플래폼인 아두이노를 이용하여 디지털 논리회로의 지속 가능한 새로운 실습 방법을 제안하는 데 있다. 이를 위해 이 연구에서는 ADDIE 모델과 Lee(2020)의 모델에 기반하여, 아두이노로 기본 게이트 회로를 구현하는 방 법을 제시하였다. 이 연구의 결과 아두이노를 이용하여 지속 가능한 디지털 논리 회로의 실습이 구현 가능함을 확인하였다. 또 한, 이 연구의 결과로 아두이노, 버튼, LED 등과 같은 부품 간의 회로 구성 방법, 배선도, 프로그래밍 소스 코드, 적용 결과물 등을 제시하였다. 이 연구에서 제안된 실습 내용은 비전공학생이나 초, 중등학생을 대상으로 한 디지털 논리회로 실습 교육에 활용될 수 있을 것이며, 메이커 교육, 코딩 교육, 소프트웨어 교육에서도 활용될 수 있을 것이다. 이 연구에서는 아두이노 및 C 언어와 같이 수 십 여년 간 지속적으로 사용되는 오픈 하드웨어와 소프트웨어를 사용하였기 때문에, 향후에도 계속적으로 디지 털 논리 회로의 실습에 활용될 수 있을 것이다. The purpose of this study is to propose a new, sustainable method for creating and studying digital logic circuits hands-on activity, using the Arduino open-source platform. For the purouse, in this study, based on the ADDIE model and the model of Lee (2020), a method of implementing a basic gate circuit with Arduino was presented. As a result of this study, it was confirmed that it is possible to implement sustainable digital logic circuit practice using Arduino. In addition, as a result of this study, circuit configuration method, wiring diagram, programming source code, application results, and other design details for the circuit using components such as the Arduino, buttons, and LEDs were presented. The method proposed in this study can be used in digital logic circuit hands-on classes for non-major university students, primary school students, and secondary school students, and can also be used in maker education, coding education, and software education. As this method needs only open-source hardware and software, such as Arduino and the C language, that are freely available, it can be used to practice making digital logic circuits in a sustainable way in the future.

Electromyographic analysis according to shoe weight during ambulation

Lee, Eunsang,Lee, Byunghoon,Cho, Juchul,Lee, Yongwoo,Lee, Seungwon korean Academy of Physical Therapy Rehabilitation 2015 Physical therapy rehabilitation science Vol.4 No.2

Objective: To examine the effects of different shoe weights on lower leg muscle fatigue when walking by electromyographic (EMG) analysis due to the most effective weight for loading not being established. Design: Cross-sectional study. Methods: Thirty healthy university students (15 male, 15 female) were enrolled and randomly assigned into three conditions, which included wearing athletic shoes with an addition of 300 g, 500 g, and 1,000 g weights respectively. Prior to walking, all subjects were instructed to sit in a chair for 10 minutes. All subjects walked at a speed of 3.6 m/s on a treadmill for 20 minutes without rest. EMG measurements were taken using the median power frequency to assess for the effect of the different weight of shoes on muscle fatigue of the soleus, gastrocnemius, and tibialis anterior while walking on a treadmill in an upright posture. EMG measurements were taken during the first and last 30 seconds of walking. Results: In terms of muscle fatigue, for the soleus, the median power frequency was significantly lower with 1,000 g compared with 300 g and 500 g (p<0.05). For the tibialis anterior, the median power frequency was significantly lower with 1,000 g than 300 g and 500 g (p<0.05). For the gastrocnemius, the median power frequency was significantly lower with 1,000 g compared with 300 g (p<0.05). Conclusions: Increased shoe weight increases soleus, gastrocnemius, and tibialis anterior muscle fatigue during ambulation.

A 2-GS/s 6-bit Single-channel Speculative Loop-unrolled SAR ADC with Low-overhead Comparator Offset Calibration in 28-nm CMOS

Eunsang Lee,Sanghun Lee,Changhyun Pyo,Hyunseok Kim,Jaeduk Han 대한전자공학회 2024 Journal of semiconductor technology and science Vol.24 No.4

This paper presents a 2-GS/s 6-bit single-channel speculative loop-unrolled successive approximation register (SAR) analog-to-digital converter (ADC) with comparator offset calibration. The proposed loop-unrolled SAR ADC speeds up its conversion speed by selecting one of the pre-determined capacitive digital-to-analog converters (CDACs) speculatively. A foreground comparator offset calibration for the speculative loop-unrolled SAR ADC is introduced to improve the ADC performance by reducing the input parasitic capacitance and minimizing the logic fan-out in comparator internal clock path. The CDAC switching method that minimizes the variation of the output common-mode (CM) voltage is applied to be compatible with the proposed foreground comparator offset calibration. In addition, the modified double-tail comparator structure is adopted for reducing the kickback noise without the speed overhead. The proposed SAR ADC achieves a 2-GS/s sampling rate with only a single-channel without a time-interleaving technique. The ADC is fabricated in 28-nm CMOS and has a 33.1-dB SNDR at a low input frequency and a 29.9-dB SNDR at the Nyquist frequency with a 6.2- mW power consumption from 1.2-V supply voltage.

Segregated structures of ring polymer melts near the surface: a molecular dynamics simulation study

Lee, Eunsang,Jung, YounJoon The Royal Society of Chemistry 2015 SOFT MATTER Vol.11 No.30

<P>We study structural properties of a ring polymeric melt confined in a film in comparison to a linear counterpart using molecular dynamics simulations. Local structure orderings of ring and linear polymers in the vicinity of the surface are similar to each other because the length scale of surface-monomer excluded volume interactions is smaller than the size of an ideal blob of the ring. In a long length scale, while the Silberberg hypothesis can be used to provide the physical origin of the confined linear polymer results, it no longer holds for the ring polymer case. We also present different structural properties of ring and linear polymers in a melt, including the size of polymers, the adsorbed amount, and the coordination number of a polymer. Our observation reveals that a confined ring in a melt adopts a highly segregated conformation due to a topological excluded volume repulsion, which may provide a new perspective to understand the nature of biological processes, such as territorial segregation of chromosomes in eukaryotic nuclei.</P> <P>Graphic Abstract</P><P>A ring polymer in a melt under confinement shows a very compact and segregated structure. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5sm01097g'> </P>

Time-domain Continuous-time Delta-sigma Modulator using VCO-based Integrator and GRO-based Quantizer

Eunsang Lee,Jaeduk Han 대한전자공학회 2022 Journal of semiconductor technology and science Vol.22 No.4

This paper presents a 3rd-order time-domain continuous-time delta-sigma modulator (CTDSM) using two voltage-controlled oscillator (VCO)-based integrators and a gated ring oscillator (GRO)-based quantizer. The GRO-based quantizer has 1st-order noise-shaping characteristics without the increase of the signal transfer function (STF) order and has magnificent linearity. Also, the output of the GRO-based quantizer has an intrinsic data weighted averaging (DWA)-based dynamic element matching (DEM) pattern that is less susceptible to the DAC mismatch. The PWM signal, which is the input of the GRO-based quantizer, is generated by the VCO-based integrator without additional blocks. In the pre-layout simulation, the CTDSM consumes 3.84 mW and achieves an SNDR of 71.2 dB at a 400-MSs sampling frequency and a 10-MHz bandwidth.

The Effect of Transcranial Direct Current Stimulation on Smartphone Addiction and Stress: a randomized controlled study

Eunsang Lee 물리치료재활과학회 2021 Physical therapy rehabilitation science Vol.10 No.1

Objective: Smartphone addiction can cause forward head posture, carpal tunnel syndrome and depression, and anxiety. Various interventions have been proposed to resolve Smartphone addiction. However, research regarding the efficacy of these interventions remains lacking. This study was conducted to investigate the effect of tDCS (Transcranial Direct Current Stimulation) on smartphone addiction solution and stress reduction. Design: A randomized controlled trial. Methods: The participants were divided randomly into two group (tDCS vs. Control). tDCS was applied to 41 adults (22.95±2.76 years). The tDCS group was applied 2 mA, for 13 minutes twice over a 26 minute period (n1 = 21). The control (n2 = 20) was not applied after padding and was applied twice for 13 minutes over a 26 minute period. This study was conducted four times a week for a total of four weeks. Results: Smartphone addiction for tDCS showed significant improvement in the results in the S-score (p<0.05, 95% CI: 0.702, 4.922), and the result of heart rate (HR) and skin conductivity (SC) to stress. The tDCS group and control group showed no significant decrese in the results in the HR (p>0.05, 95% CI: -3.390, 8.332), but tDCS group showed significant decrese in the results in the SC (p<0.05, 95% CI: 0.060, 1.343) Conclusions: This study suggected that smartphone addiction treatment and decreses of stress. The use of tDCS will reduce the addiction rate of adults and reduce stress, so that possible side effects in society can be solved.

빅데이터 분석을 통한 라즈베리파이 교육에 대한 사회적 인식

이은상(Lee Eunsang) 학습자중심교과교육학회 2022 학습자중심교과교육연구 Vol.22 No.1

목적 이 연구의 목적은 빅데이터 분석 방법으로 라즈베리파이 교육의 사회적 인식을 분석하는 데 있다. 방법 이를 위해 텍스톰 사이트를 통해 ‘라즈베리파이’와 ‘교육’이 포함된 키워드를 중심으로 빅데이터를 추출하였고, 이 데이터를 텍스톰 사이트와 UNICET 프로그램을 이용하여 정제 및 분석하였다. 결과 이 연구에서는 빈도 분석, TF-IDF 분석, 연결 중심성 분석, N-gram 분석 등의 텍스트 마이닝 분석 결과 ‘아두이노’, ‘컴퓨터’, ‘교육’, ‘코딩’, ‘활용’ 등이 주요 키워드임을 확인하였다. 또한, 의미 연결망 분석을 위해 CONCOR 분석을 수행한 결과 ‘라즈베리파이 활용 교육’, ‘라즈베리파이 교육 운영’, ‘라즈베리파이 기원’ 등 3개의 카테고리를 확인할 수 있다. 결론 이 연구를 통해 인터넷상에서 라즈베리파이 교육과 관련된 일반 대중들의 여러 가지 의미 있는 사회적 인식을 확인할 수 있었다. 이 연구의 결과는 라즈베리파이 관련 교육을 연구하는 연구자나 기관의 학술 연구에 활용될 수 있는 기초 자료로 활용될 수 있을 것이다. Objectives The purposes of this study were to analyze the social perception of Raspberry Pi and education using the big data analysis method. Methods It was extracted big data from keywords including ‘Raspberry Pi’ and ‘education’ through the Textom website and refined and analyzed the data using the Textom and the UNICET program. In this study, text mining analysis such as frequency analysis, TF-IDF analysis, degree centrality analysis, and N-gram analysis was performed, and CONCOR analysis was performed for semantic network analysis. Results As a result of text mining analysis, it was confirmed that ‘Arduino’, ‘computer’, ‘coding’, ‘education’, and ‘use’ were the major keywords. As a result semantic network analysis, three clusters could be identified: ‘education using Raspberry Pi’, ‘operation of Raspberry Pi education’, and ‘origin of Raspberry Pi’. Conclusions Through this study, it was possible to confirm various meaningful social perceptions of the general public in relation to Raspberry Pi education on the Internet. This study’s results provide fundamental data for academic research in Raspberry Pi-related education.