• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• 자동차안전학회지
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• 제12권4호
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• pp.7-12
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• 2020

Recently, automobile industries have developed ADAS, smart cars, connected cars, automated driving systems, which use a variety of sensor systems - ultrasonics, cameras, lidars and radars - and communication systems. It is necessary to examine the electromagnetic immunity of vehicles equipped with the sensor systems due to the fact that the normal operation of those systems is very important to the safety of the vehicles. The electromagnetic immunity tests are carried out in an electromagnetic semi anechoic chamber, which is cut off from the outside. It is difficult to create test environments in which the camera sensor systems of vehicles work properly in the test chamber. In this study, test jigs were designed and tested and as a result they are shown to be effective to create test environments for electromagnetic immunity tests of vehicles equipped with camera sensors. We also proposed additional safety standards for immunity tests of vehicles with camera systems that currently do not exist.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 추계학술발표대회
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• pp.805-808
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• 2011

스마트워크란 시간과 장소의 제약 없이 업무를 수행하는 유연한 근무형태를 말한다. 스마트워크 근무 유형에는 가정에서 본사 통신망을 접속해 업무를 수행하는 재택근무와 주거지 인근 원격사무실에 출근하는 스마트워크 센터 근무, 그리고 스마트폰 등을 이용해 현장에서 업무를 수행하는 이동근무가 있다. 스마트워크를 통하여 기업들은 업무 효율과 생산성 향상시킬 수 있다. 또한 대도시 교통 혼잡을 줄이고 여성의 육아부담을 줄일 수 있어 정부에서 확대 지원하는 사업이다. 하지만 스마트워크의 특성상 원격으로 접속하여 업무를 처리하므로 공격자가 로그인 정보를 취득 시에는 위협이 존재한다. 또한 스마트워크 센터에서 사원 관리 취약성과 비인가자에 대한 접근이 용이하기 때문에 문제가 될 수 있다. 이에 따라 본 논문에서는 QR코드를 이용한 승인 인증 시스템을 제안하게 되었다.

• 아태비즈니스연구
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• 제14권2호
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• pp.85-100
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• 2023

Purpose - The purpose of this study is to identify the factors of shocking events in the career aspect experienced by Korean workers in the context of the Covid-19 pandemic, and to find out whether these career shocks affect individual perceptions of the importance of subjective career success. Design/methodology/approach - In the survey of 146 respondents, the career shock events experienced in the context of the Covid-19 pandemic were largely divided into three categories; 'work change', 'employment anxiety', and 'life anxiety'. For the subjective career success, seven dimensions - 'financial security', 'financial achievement', 'entrepreneurship', 'positive relationship', 'positive impact', 'learning and development', 'work-life balance' - were used. Findings - As a result, there was no difference in the perception of subjective career success due to the experience of 'work change' during the Covid-19 period. However, the respondents who experienced 'employment anxiety' came to recognize that 'financial security' and 'financial achievement' were more increasing in terms of the degree of difference of importance. And respondents who experienced 'lifetime anxiety' perceived that the degree of difference of importance was increasing in the six dimensions except for 'social influence'. Particularly, the increase in the importance of 'work-life balance' and 'positive relationship' was found to be the greatest among the career success dimensions. Research implications or Originality - Finally, it was concluded that changes in the external environment such as Covid-19 pandemic influence as a career shock and affect the level of importance in subjective career success perception. Based on the results, the theoretical implication on current career study and some practical implications for organizational career management were suggested.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권5호
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• pp.1339-1355
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• 2023

Localization is a hot research spot for many areas, especially in the mobile robot field. Due to the weak signal of the global positioning system (GPS), the alternative schemes in an indoor environment include wireless signal transmitting and receiving solutions, laser rangefinder to build a map followed by a re-localization stage and visual positioning methods, etc. Among all wireless signal positioning techniques, Wi-Fi is the most common one. Wi-Fi access points are installed in most indoor areas of human activities, and smart devices equipped with Wi-Fi modules can be seen everywhere. However, the localization of a mobile robot using a Wi-Fi scheme usually lacks orientation information. Besides, the distance error is large because of indoor signal interference. Another research direction that mainly refers to laser sensors is to actively detect the environment and achieve positioning. An occupancy grid map is built by using the simultaneous localization and mapping (SLAM) method when the mobile robot enters the indoor environment for the first time. When the robot enters the environment again, it can localize itself according to the known map. Nevertheless, this scheme only works effectively based on the prerequisite that those areas have salient geometrical features. If the areas have similar scanning structures, such as a long corridor or similar rooms, the traditional methods always fail. To address the weakness of the above two methods, this work proposes a coarse-to-fine paradigm and an improved localization algorithm that utilizes Wi-Fi to assist the robot localization in a geometrically similar environment. Firstly, a grid map is built by using laser SLAM. Secondly, a fingerprint database is built in the offline phase. Then, the RSSI values are achieved in the localization stage to get a coarse localization. Finally, an improved particle filter method based on the Wi-Fi signal values is proposed to realize a fine localization. Experimental results show that our approach is effective and robust for both global localization and the kidnapped robot problem. The localization success rate reaches 97.33%, while the traditional method always fails.

• 적정기술학회지
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• 제7권2호
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• pp.196-205
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• 2021

산업안전에 대한 관심이 증가하는 가운데 최근 제조현장에서 다양한 방법으로 적용되고 있는 스마트공장 기술을 활용한 산업재해 방지 기술도 다양하게 연구되고 있다. 하지만 현실적인 문제로 인해 산업재해의 큰 비중을 차지하는 중소기업에서 이러한 스마트공장 기술의 적용을 통한 산업재해 방지에 어려움이 따르고 있다. 본 연구에서는 산업재해 유형별 맞춤형 모니터링 및 경보 시스템을 개발하고 실제 현장에 적용하였으며, 이를 통해 중소기업에서 활용할 수 있는 적정 스마트공장 기술을 통한 산업재해 방지 기술을 실증하였다. 작업자 신체 접근, 누전 및 과전류, 고온에 의한 화재 및 화상, 유해물질 배출이라는 네 가지 주요 재해 유형에 대해 비전센서, 전류센서, 온도센서 및 가스센서를 활용하여 맞춤형 모니터링 시스템을 구축하였다. 더불어 모니터링 된 위험요소 빠르게 인지할 수 있도록 작업환경에 맞는 알림 방안을 적용하고, 실시간 데이터 전송 및 디스플레이를 활용하여 작업자와 관리자가 재해 위험을 효과적으로 인지할 수 있도록 하였다. 이러한 적정 스마트공장 기술의 적용 및 실증을 통한 효과를 확인하고 이러한 산업안전 기술의 확산에 대해 논의하고자 한다.

• 한국인터넷방송통신학회논문지
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• 제14권4호
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• pp.101-106
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• 2014

전 세계적으로 초고속 인터넷 망의 확충과 스마트폰의 보급에 따라 클라우드 컴퓨팅의 장점을 극대화 할 수 있는 시대가 도래 하였다. 본 연구에서는 클라우드 컴퓨팅을 활용한 모바일 환경에서의 의료영상 볼륨 렌더링 아키텍처를 제안한다. 해당 아키텍처는 값 비싼 워크스테이션 서버와 스토리지를 대체하기 위해 클라우드 컴퓨팅 서비스 중 하나인 IaaS(Infrastructure as a Service)를 사용한다. 그리고 모바일 하드웨어의 제약에서 벗어나 안정적인 렌더링을 위해 WebGL을 이용한 가시화 방법을 제안한다. 이번 연구를 통해서 모바일 환경에서의 효율적인 의료영상 볼륨 렌더링 서비스에 적용될 수 있는 기초 연구가 될 수 있기를 기대한다.

• Smart Structures and Systems
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• 제16권4호
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• pp.607-621
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• 2015

Wireless sensor technology has been opened up numerous opportunities to advanced health and maintenance monitoring of civil infrastructure. Compare to the traditional tactics, it offers a better way of providing relevant information regarding the condition of building structure health at a lower price. Numerous domestic buildings, especially longer-span buildings have a low frequency response and challenging to measure using deployed numbers of sensors. The way the sensor nodes are connected plays an important role in providing the signals with required strengths. Out of many topologies, the dense and sparse topologies wireless sensor network were extensively used in sensor network applications for collecting health information. However, it is still unclear which topology is better for obtaining health information in terms of greatest components, node's size and degree. Theoretical and computational issues arising in the selection of the optimum topology sensor network for estimating coverage area with sensor placement in building structural monitoring are addressed. This work is an attempt to fill this gap in high-rise building structural health monitoring application. The result shows that, the sparse topology sensor network provides better performance compared with the dense topology network and would be a good choice for monitoring high-rise building structural health damage.

• Smart Structures and Systems
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• 제1권4호
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• pp.355-368
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• 2005

Large and complex structures are being built now-a-days and, they are required to be functional even under extreme loading and environmental conditions. In order to meet the safety and maintenance demands, there is a need to build sensors integrated structural system, which can sense and provide necessary information about the structural response to complex loading and environment. Sophisticated tools have been developed for the design and construction of civil engineering structures. However, very little has been accomplished in the area of monitoring and rehabilitation. The employment of appropriate sensor is therefore crucial, and efforts must be directed towards non-destructive testing techniques that remain functional throughout the life of the structure. Fiber optic sensors are emerging as a superior non-destructive tool for evaluating the health of civil engineering structures. Flexibility, small in size and corrosion resistance of optical fibers allow them to be directly embedded in concrete structures. The inherent advantages of fiber optic sensors over conventional sensors include high resolution, ability to work in difficult environment, immunity from electromagnetic interference, large band width of signal, low noise and high sensitivity. This paper brings out the potential and current status of technology of fiber optic sensors for civil engineering applications. The importance of employing fiber optic sensors for health monitoring of civil engineering structures has been highlighted. Details of laboratory studies carried out on fiber optic strain sensors to assess their suitability for civil engineering applications are also covered.

• Smart Structures and Systems
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• 제24권6호
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• pp.759-768
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• 2019

In nuclear fusion reactors, the key structural component (i.e., the plasma-facing component) undergoes high heat flux cyclic loading. To ensure the safety of fusion reactors, an experimental study on the temperature-induced creep of stainless steel under heat flux cyclic loading was performed in the present work. The strains were measured using a stereo digital image correlation technique (3D-DIC). The influence of the heat haze was eliminated, owing to the use of a vacuum environment. The specimen underwent heat flux cycles ($500^{\circ}C-1000^{\circ}C$) with different mechanical preloads (0 kN, 10 kN, 30 kN, and 50 kN). The results revealed that, for a relatively large preload (for example, 50 kN), a single temperature cycle can induce a residual strain of up to $15000{\mu}{\varepsilon}$.