• 한국산업융합학회 논문집
• /
• 제25권3호
• /
• pp.333-340
• /
• 2022

Recently, the use of large-capacity secondary batteries for electric vehicles is rapidly increasing, and accordingly, the demand for technologies and equipment for battery reliability evaluation is increasing significantly. The existing short circuit test equipment for evaluating the stability of the existing secondary battery consists of relays, MCs, and switches, so when a large current is energized during a short circuit, contact fusion failures occur frequently, resulting in high equipment maintenance and repair costs. There was a disadvantage that repeated testing was impossible. In this paper, we developed an electronic short circuit test device that realizes stable switching operation when a large-capacity power semiconductor switch is energized with a large current, and applied smart ICT technology to this electronic short circuit stability test system to achieve high speed and high precision through communication with the master. It is expected that the inspection history management system based on data measurement, database format and user interface will be utilized as essential inspection process equipment.

• 전력전자학회논문지
• /
• 제27권3호
• /
• pp.206-213
• /
• 2022

This paper presents setting up a laboratory-scale testbed to estimate the aging of power MOSFET devices and integrated power modules by measuring its on-state voltage and current. Based on the aging mechanisms of the component inside the power module (e.g., bond-wire, solder layer, and semiconductor chip), a system to measure the on-state resistance of device-under-test (DUT) is designed and experimented: a full-bridge circuit applies current stress to DUT, and a temperature chamber controls the ambient temperature of DUT during the aging test. The on-state resistance of SiC MOSFET measured by the proposed testbed was increased by 2.5%-3% after 44-hour of the aging test.

• 한국공간구조학회논문집
• /
• 제22권3호
• /
• pp.49-56
• /
• 2022

Tuned mass damper (TMD) is widely used to reduce dynamic responses of structures subjected to earthquake loads. A smart tuned mass damper (STMD) was proposed to increase control performance of a traditional passive TMD. A lot of research was conducted to investigate the control performance of a STMD based on analytical method. Experimental study of evaluation of control performance of a STMD was not widely conducted to date. Therefore, seismic response reduction capacity of a STMD was experimentally investigated in this study. For this purpose, a STMD was manufactured using an MR (magnetorheological) damper. A simple structure presenting dynamic characteristics of spacial roof structure was made as a test structure. A STMD was made to control vertical responses of the test structure. Two artificial ground motions and a resonance harmonic load were selected as experimental seismic excitations. Shaking table test was conducted to evaluate control performance of a STMD. Control algorithms are one of main factors affect control performance of a STMD. In this study, a groundhook algorithm that is a traditional semi-active control algorithm was selected. And fuzzy logic controller (FLC) was used to control a STMD. The FLC was optimized by multi-objective genetic algorithm. The experimental results presented that the TMD can effectively reduce seismic responses of the example structures subjected to various excitations. It was also experimentally shown that the STMD can more effectively reduce seismic responses of the example structures conpared to the passive TMD.

• 대한인간공학회지
• /
• 제35권6호
• /
• pp.519-533
• /
• 2016

Objective: This study lays its aims at the definition of relevant operation method and function by researching on the value to be brought when applying smart device that can hand carry soft and flexible materials like jelly. Background: New technology and material play a role in bringing type transformation of interface and change of operation system. Recently, importance has been increased on the study of Organic User Interface (OUI) that conducts research on the value of new method of input and output adopting soft and flexible materials for various instruments. Method: For fulfillment of the study, 27 kinds of gestures have been defined that are usable in handheld device based on existing studies. Quantitative research of survey was conducted of adult male and female of 20s through 30s and an analysis was done on the function that can be linked to gestures with highest level of satisfaction. In order to analyze needs and hurdles of users for the defined gesture, a focus group interview was conducted aiming at the groups of early adopters and ordinary users. Results: As a result, it was found that users have much value regarding usability and fun for elastic device and analysis could be conducted on preferred gesture and its linkable functions. Conclusion: What is most significant with this study is that it sheds new light on the values of a device made of elastic material. Beyond finding and defining the gestures and functions that can be applied to a handheld elastic device, the present study identified the value elements of an elastic device - 'usability and 'fun' -, which users can basically desire from using it. Application: The data that this study brought forth through preference and satisfaction test with the gestures and associated functions will help commercialize an elastic device in future.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 추계학술대회
• /
• pp.813-815
• /
• 2016

본 논문에서는 뇌파데이터를 기반으로 한 디바이스 제어 시스템을 구현한다. Brain-Computer Interface(BCI) 기술은 언어나 신체의 동작을 거치지 않고 직접 시스템에 전달할 수 있다. 상태의 변화에 따른 뇌파를 실시간으로 감지하여 디바이스를 제어함으로써 움직임이 불편한 장애인이나 수험생, 멀티태스킹이 필요한 사람 등 다양한 서비스 대상자에게 편리한 생활을 할 수 있도록 도와준다. 또한, 홈 디바이스 제어 시스템 등 응용서비스를 개발할 수 있다. 이를 위해 논문에서 구현한 디바이스 제어 시스템은 뇌파 측정 헤드셋으로부터 수집된 데이터를 기반으로 사용자의 스마트폰과 연동하여 전원 및 오디오를 제어한다. 집중도에 의해 전원 ON/OFF 동작을 제어하고, 명상도와 눈 깜빡임에 의해 오디오를 제어하는 서비스 기능을 지원한다. 실험실 테스트를 통해 뇌파데이터를 이용한 디바이스 제어가 성공적으로 동작되는 것을 확인하였다.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제22권10호
• /
• pp.488-496
• /
• 2016

이 논문에서는 대용량 해석 데이터 가시화 시스템을 위한 가상현실(VR) 인터페이스의 세부적인 개발내용에 대해 설명한다. 여기서 소개하는 VR 인터페이스는 오픈소스 VR 프레임워크인 VR Juggler에 기반을 두고 있다. VR Juggler는 여러 장점에도 불구하고, 이벤트 드리븐 방식을 지원하지 않으며 클러스터 환경에서 실행될 때 노드 사이의 동기화가 제한적으로 지원되는 등 한계를 보여주기도 한다. 이 논문에서는 이벤트 처리, 애니메이션 재생이나 외부 서버와의 통신 시 클러스터 노드 간 동기화 및 데이터 공유와 같이 VR Juggler를 이용해서 어플리케이션을 개발할 때 발생하는 문제의 해결방안을 실제 개발사례와 함께 제시한다. 그리고 가상현실 입력장치의 단점을 보완한 스마트 디바이스 기반 인터페이스에 대해서도 소개하며, 외부 사용자를 대상으로 진행한 사용성 평가결과를 통해 VR 인터페이스와 스마트 디바이스 인터페이스의 유용성을 검증한다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제28권2호
• /
• pp.129-152
• /
• 2019

Purpose The purpose of this study is to empirically identify the risky behavior of mobile device users using the Internet of Things on a situational perspective. Design/methodology/approach This study made a design of the research model based on model of the determinants of risk behavior. Data were collected through a survey including hypothetical scenario. SmartPLS 2.0 was used for the structural model analysis and t-test was conducted to compare the between normal and situational behavior. Findings The results were as follows. First, the central roles of risk propriety and risk perception were verified empirically. Second, we identified the role of locus of control as a new factor of impact on risky behavior. Third, mobile risk propensity has been shown to increase risk perception. Fouth, it has been shown that risk perception does not directly affect risky behavior and reduce the relationship between mobile risk propensity and risk behavior. According to the empirical analysis result, Determinants of risk behavior for mobile users were identified based on a theoretical framework. And it raised the need to pay attention to the impact of locus of control on risk behavior in the IS security field. It provided direction to the approach to risky behavior of mobile device users. In addition, this study confirmed that there was a possibility of taking risky behavior in the actual decision-making.

• 한국정보통신학회논문지
• /
• 제19권7호
• /
• pp.1719-1727
• /
• 2015

본 논문에서는 스마트 교육 관련 기술 개발의 일환으로 태블릿 기기와 전자칠판 시스템간의 연동 기술에 대해 연구하였다. 이를 위해 우선적으로 태블릿 기기와 전자칠판 시스템 상에서 강의 자료 관리, 페이지 전환 및 기본적인 판서가 가능한 판서 소프트웨어를 구현하였다. 그리고 이들 판서 소프트웨어들 간에 제어 정보 및 판서 정보를 주고받기 위한 데이터 포맷을 정의한 다음 소켓 프로그래밍을 통해 두 디바이스 간에 실시간 양방향으로 연동하는 기능을 구현하였다. 그 결과로 태블릿 기기 상에서의 페이지 전환 이벤트나 판서 정보는 전자칠판 시스템에 실시간으로 전달되어 대형 스크린에 디스플레이 되고, 반대로 전자칠판에서의 이벤트나 판서 정보는 태블릿 기기에 실시간 표출이 된다. 태블릿 기기와 전자칠판 시스템간의 양방향 연동 기능의 성능을 응답 오류율, 지연시간 및 통신 커버리지 측면에서 자체 평가를 실시하고, 필드테스트를 통해 실제 교육 환경에 적용 가능한 우수한 성능임을 입증하였다.

• International Journal of Advanced Culture Technology
• /
• 제8권1호
• /
• pp.218-225
• /
• 2020

Purpose Wearable devices are widely used in our daily life. The purpose of this study is to investigate the relationship between persuasive designs of fitness trackers and users' physical activity behavior. Methods To test the research model, data was collected from a web-based survey in China, resulting in an effective sample of 166 usable questionnaires. The survey was restricted only to respondents who wear a fitness tracker. Results The sample surveyed in this study indicated that half of the respondents had been wearing a smart fitness tracker shorter than one year, and only 27% were long-time users (longer than two years). Dialogue support and social support strategies were both proved to be effective in increasing users' workout behavior intention. Social support strategies had a greater effect on behavior change than dialogue support strategies. Conclusion The findings from this study make several contributions to the practice. Wearable devices developers can employ the result from this study to help them design devices, which can persuade people to do more exercises and preserve a healthier life.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
• /
• pp.223-226
• /
• 2003

This paper presents a realization of sensor signal processing(noise filtering) and Fieldbus based communication for condition monitoring of check valve. we first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, and their frequencies were analyzed to find the informative band. To reject background noises, bandpass filters have been designed. Also, to send the processed data to a remote site, wired communication facility has been realized via DeviceNet.