• Title/Summary/Keyword: Multi-Device Use

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Small Energy Generator Using Multilayer Piezoelectric Devices (적층형 압전 소자를 이용한 미소 에너지발생장치)

  • Jeong, Soon-Jong;Kim, Min-Soo;Kim, In-Sung;Song, Jae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.261-261
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    • 2007
  • Wearable and ubiquitous micro systems will be greatly growing and their related devices should be self-powered in order to avoid the replacement of finite power sources, for example, by scavenging energy from the environment. With ever reducing power requirements of both analog and digital circuits, power scavenging approaches are becoming increasingly realistic. One approach is to drive an electromechanical converter from ambient motion or vibration. Vibration-driven generators based on electromagnetic, electrostatic and piezoelectric technologies have been demonstrated. Among various generator types proposed so far, piezoelectric generator possesses considerable potential in micro system. To overcome low mechanical-to- electric energy conversion, the piezoelectric device should activate in resonance mode in response to external vibration. Normally, the external vibration excretes at low frequency ranging 0.1 to 200 Hz, whereas the resonant frequencies of the devices are fixed as constant. Therefore, keeping their resonant mode in varying external vibration can be one of important points in enhancing the conversion efficiency. We investigated the possibility of use of multi-bender type piezoelectric devices. To match the external vibration frequency with the device resonant frequency, the various devices with different resonant frequency were chosen. Under an external vibration acceleration of 0.1G at 120 Hz, the device exhibited a peak-to-peak voltage of 2.8 V and a power of 0.5 mw in resonance mode.

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Study on Design Research using Semantic Network Analysis

  • Chung, Jaehee;Nah, Ken;Kim, Sungbum
    • Journal of the Ergonomics Society of Korea
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    • v.34 no.6
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    • pp.563-581
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    • 2015
  • Objective: This study was conducted to investigate the potential of sematic network analysis for design research. Background: As HCD (Human-Centered Design) was emphasized, lots of design research methodologies were developed and used in order to find user needs. However, it is still difficult to discover users' latent needs. This study suggests the semantic network analysis as a complementary means for design research, and proved its potential through the practical application, which compares multi-screen purchase and usage behaviors between America and China. Method: We conducted an in-depth interview with 32 consumers from USA and China, and analyzed interview texts through semantic network analysis. Cross cultural differences in purchase and usage behaviors were investigated, based on measuring centrality and community modularity of devices, functions, key buying factors and brands. Results: Americans use more services and functions in the multi-screen environment, compared to Chinese. As a device substitutes other devices, traditional boundaries of the devices are disappearing in the USA. Americans consider function to recall Apple, but Chinese consider function, design and brand to recall Apple, Sony and Samsung as an important brand at the time of their purchase. Conclusion: This study shows the potential of semantic network analysis for design research through the practical application. Semantic network analysis presents how the concepts regarding a theme are structured in the cognitive map of users with visual images and quantitative data. Therefore, it can complement the qualitative analysis of the existing design research. Application: As the design environment becomes more and more complicated like multi-screen environment, semantic network analysis, which is able to provide design insights in the intuitive and holistic perspective, will be acknowledged as an effective tool for further design research.

A Study on the Tele-controller System of Navigational Aids Using Hybrid Communication (하이브리드 통신을 이용한 항로표지의 원격관리 제어시스템에 관한 연구)

  • Jeon, Joong-Sung;Oh, Jin-Seok
    • Journal of Advanced Marine Engineering and Technology
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    • v.35 no.6
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    • pp.842-848
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    • 2011
  • A fabricated hybrid control board using multi-communication is designed with a low power 8-bit microcontroller, ATxmega128A1. The microcontroller consists of 8 UART (Universal asynchronous receiver/transmitter) ports, 2 kbytes EEPROM, 128 kbytes flash memory, 8 kbytes SRAM. The 8 URAT ports are used for a multi-communication modem, a GPS module, etc. The EEPROM is used for saving a configuration for running programs, and the flash memory of 128 kbytes is used for storing a F/W (Firm Ware), and the 8 kbytes SRAM is used for stack and for storing memory of global variables while running programs. If we use the multi-communication of CDMA, TRS and RF to remotely control Aid to Navigation, it is able to remove the communication shadow area. Even though there is a shadow area for an individual communication method, we can select an optimal communication method. The compatibility of data has been enhanced as using of same data frame per communication device. For the test, 8640 of data have been collected from each buoy during 30 days in every 5 minutes and the receiving rate of the data has shown more than 85 %.

Wearable Computers

  • Cho, Gil-Soo;Barfield, Woodrow;Baird, Kevin
    • Fiber Technology and Industry
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    • v.2 no.4
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    • pp.490-508
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    • 1998
  • One of the latest fields of research in the area of output devices is tactual display devices [13,31]. These tactual or haptic devices allow the user to receive haptic feedback output from a variety of sources. This allows the user to actually feel virtual objects and manipulate them by touch. This is an emerging technology and will be instrumental in enhancing the realism of wearable augmented environments for certain applications. Tactual displays have previously been used for scientific visualization in virtual environments by chemists and engineers to improve perception and understanding of force fields and of world models populated with the impenetrable. In addition to tactual displays, the use of wearable audio displays that allow sound to be spatialized are being developed. With wearable computers, designers will soon be able to pair spatialized sound to virtual representations of objects when appropriate to make the wearable computer experience even more realistic to the user. Furthermore, as the number and complexity of wearable computing applications continues to grow, there will be increasing needs for systems that are faster, lighter, and have higher resolution displays. Better networking technology will also need to be developed to allow all users of wearable computers to have high bandwidth connections for real time information gathering and collaboration. In addition to the technology advances that make users need to wear computers in everyday life, there is also the desire to have users want to wear their computers. In order to do this, wearable computing needs to be unobtrusive and socially acceptable. By making wearables smaller and lighter, or actually embedding them in clothing, users can conceal them easily and wear them comfortably. The military is currently working on the development of the Personal Information Carrier (PIC) or digital dog tag. The PIC is a small electronic storage device containing medical information about the wearer. While old military dog tags contained only 5 lines of information, the digital tags may contain volumes of multi-media information including medical history, X-rays, and cardiograms. Using hand held devices in the field, medics would be able to call this information up in real time for better treatment. A fully functional transmittable device is still years off, but this technology once developed in the military, could be adapted tp civilian users and provide ant information, medical or otherwise, in a portable, not obstructive, and fashionable way. Another future device that could increase safety and well being of its users is the nose on-a-chip developed by the Oak Ridge National Lab in Tennessee. This tiny digital silicon chip about the size of a dime, is capable of 'smelling' natural gas leaks in stoves, heaters, and other appliances. It can also detect dangerous levels of carbon monoxide. This device can also be configured to notify the fire department when a leak is detected. This nose chip should be commercially available within 2 years, and is inexpensive, requires low power, and is very sensitive. Along with gas detection capabilities, this device may someday also be configured to detect smoke and other harmful gases. By embedding this chip into workers uniforms, name tags, etc., this could be a lifesaving computational accessory. In addition to the future safety technology soon to be available as accessories are devices that are for entertainment and security. The LCI computer group is developing a Smartpen, that electronically verifies a user's signature. With the increase in credit card use and the rise in forgeries, is the need for commercial industries to constantly verify signatures. This Smartpen writes like a normal pen but uses sensors to detect the motion of the pen as the user signs their name to authenticate the signature. This computational accessory should be available in 1999, and would bring increased peace of mind to consumers and vendors alike. In the entertainment domain, Panasonic is creating the first portable hand-held DVD player. This device weight less than 3 pounds and has a screen about 6' across. The color LCD has the same 16:9 aspect ratio of a cinema screen and supports a high resolution of 280,000 pixels and stereo sound. The player can play standard DVD movies and has a hour battery life for mobile use. To summarize, in this paper we presented concepts related to the design and use of wearable computers with extensions to smart spaces. For some time, researchers in telerobotics have used computer graphics to enhance remote scenes. Recent advances in augmented reality displays make it possible to enhance the user's local environment with 'information'. As shown in this paper, there are many application areas for this technology such as medicine, manufacturing, training, and recreation. Wearable computers allow a much closer association of information with the user. By embedding sensors in the wearable to allow it to see what the user sees, hear what the user hears, sense the user's physical state, and analyze what the user is typing, an intelligent agent may be able to analyze what the user is doing and try to predict the resources he will need next or in the near future. Using this information, the agent may download files, reserve communications bandwidth, post reminders, or automatically send updates to colleagues to help facilitate the user's daily interactions. This intelligent wearable computer would be able to act as a personal assistant, who is always around, knows the user's personal preferences and tastes, and tries to streamline interactions with the rest of the world.

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QR-Code Based Mutual Authentication System for Web Service (웹 서비스를 위한 QR 코드 기반 상호 인증 시스템)

  • Park, Ji-Ye;Kim, Jung-In;Shin, Min-Su;Kang, Namhi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.4
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    • pp.207-215
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    • 2014
  • Password based authentication systems are most widely used for user convenience in web services. However such authentication systems are known to be vulnerable to various attacks such as password guessing attack, dictionary attack and key logging attack. Besides, many of the web systems just provide user authentication in a one-way fashion such that web clients cannot verify the authenticity of the web server to which they set access and give passwords. Therefore, it is too difficult to protect against DNS spoofing, phishing and pharming attacks. To cope with the security threats, web system adopts several enhanced schemes utilizing one time password (OTP) or long and strong passwords including special characters. However there are still practical issues. Users are required to buy OTP devices and strong passwords are less convenient to use. Above all, one-way authentication schemes generate several vulnerabilities. To solve the problems, we propose a multi-channel, multi-factor authentication scheme by utilizing QR-Code. The proposed scheme supports both user and server authentications mutually, thereby protecting against attacks such as phishing and pharming attacks. Also, the proposed scheme makes use of a portable smart device as a OTP generator so that the system is convenient and secure against traditional password attacks.

Effects of Light Pollution from Mobile Digital Devices on Sleep and Circadian Rhythms (모바일 디지털 기기로 인한 빛공해가 수면과 일주기 리듬에 미치는 영향)

  • Lee, Youn-Jung;Cho, Chul-Hyun;Lee, Heon-Jeong
    • Sleep Medicine and Psychophysiology
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    • v.27 no.1
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    • pp.1-7
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    • 2020
  • Mobile digital devices are very familiar and useful devices in the daily life of modern people, and are used for various tasks such as communication, reading, writing, and playing media. As the use of mobile digital devices has become more prevalent, user time has also been increasing. In particular, the number of people who use digital devices before sleep is growing. The light pollution associated with these devices is classified into four categories: urban sky glow, glare, light trespass, and clutter. The pattern in which modern people use digital devices corresponds to light pollution caused by light trespass and clutter from light exposure to artificial light at night. The light pollution caused by digital devices can cause melatonin secretion suppression, delayed sleep onset, reduction of sleepiness before bedtime, and periodic rhythm and cognitive function disturbances. In addition, a study of children and adolescents showed there may be disturbances in the sleep-wake cycle and circadian rhythm, deterioration of sleep quality, and daytime fatigue due to light pollution caused by artificial light at night from mobile digital devices. A multi-faceted research effort is also necessary to investigate the healthy use of mobile digital devices based on research evidence and insights with an accurate evaluation of the influence of mobile digital devices as a form of light pollution.

Effect of Media Literacy on the Formation of Smart Divide (미디어 리터러시가 스마트 디바이드 형성에 미치는 영향)

  • Lee, Seungmin
    • Journal of the Korean Society for information Management
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    • v.38 no.2
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    • pp.19-38
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    • 2021
  • This study empirically analyzed the effect of media literacy on the formation of the smart divide, which is a multi-faceted digital divide that occurs in the context of the use of smart devices. As a result, most of the factors of media literacy affect the establishment of social relations and social network through the use of smart devices, which, in turn, leads to the expansion of the range of informational and social activities. In addition, media literacy has a significant effect on the competence to evaluate the value of information acquired through the use of smart devices. Based on these results, there can be social disparity between those who have secured media literacy and those who do not from the perspective of informational and social benefits through the use of smart devices, which can function as a mechanism to generate the smart divide.

Eco-Friendly Light Emitting Diodes Based on Graphene Quantum Dots and III-V Colloidal Quantum Dots

  • Lee, Chang-Lyoul
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.65-65
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    • 2015
  • In this talk, I will introduce two topics. The first topic is the polymer light emitting diodes (PLEDs) using graphene oxide quantum dots as emissive center. More specifically, the energy transfer mechanism as well as the origin of white electroluminescence in the PLED were investigated. The second topic is the facile synthesis of eco-friendly III-V colloidal quantum dots and their application to light emitting diodes. Polymer (organic) light emitting diodes (PLEDs) using quantum dots (QDs) as emissive materials have received much attention as promising components for next-generation displays. Despite their outstanding properties, toxic and hazardous nature of QDs is a serious impediment to their use in future eco-friendly opto-electronic device applications. Owing to the desires to develop new types of nanomaterial without health and environmental effects but with strong opto-electrical properties similar to QDs, graphene quantum dots (GQDs) have attracted great interest as promising luminophores. However, the origin of electroluminescence (EL) from GQDs incorporated PLEDs is unclear. Herein, we synthesized graphene oxide quantum dots (GOQDs) using a modified hydrothermal deoxidization method and characterized the PLED performance using GOQDs blended poly(N-vinyl carbazole) (PVK) as emissive layer. Simple device structure was used to reveal the origin of EL by excluding the contribution of and contamination from other layers. The energy transfer and interaction between the PVK host and GOQDs guest were investigated using steady-state PL, time-correlated single photon counting (TCSPC) and density functional theory (DFT) calculations. Experiments revealed that white EL emission from the PLED originated from the hybridized GOQD-PVK complex emission with the contributions from the individual GOQDs and PVK emissions. (Sci Rep., 5, 11032, 2015). New III-V colloidal quantum dots (CQDs) were synthesized using the hot-injection method and the QD-light emitting diodes (QLEDs) using these CQDs as emissive layer were demonstrated for the first time. The band gaps of the III-V CQDs were varied by varying the metal fraction and by particle size control. The X-ray absorption fine structure (XAFS) results show that the crystal states of the III-V CQDs consist of multi-phase states; multi-peak photoluminescence (PL) resulted from these multi-phase states. Inverted structured QLED shows green EL emission and a maximum luminance of ~45 cd/m2. This result shows that III-V CQDs can be a good substitute for conventional cadmium-containing CQDs in various opto-electronic applications, e.g., eco-friendly displays. (Un-published results).

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Comparative Analysis of ViSCa Platform-based Mobile Payment Service with other Cases (스마트카드 가상화(ViSCa) 플랫폼 기반 모바일 결제 서비스 제안 및 타 사례와의 비교분석)

  • Lee, June-Yeop;Lee, Kyoung-Jun
    • Journal of Intelligence and Information Systems
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    • v.20 no.2
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    • pp.163-178
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    • 2014
  • Following research proposes "Virtualization of Smart Cards (ViSCa)" which is a security system that aims to provide a multi-device platform for the deployment of services that require a strong security protocol, both for the access & authentication and execution of its applications and focuses on analyzing Virtualization of Smart Cards (ViSCa) platform-based mobile payment service by comparing with other similar cases. At the present day, the appearance of new ICT, the diffusion of new user devices (such as smartphones, tablet PC, and so on) and the growth of internet penetration rate are creating many world-shaking services yet in the most of these applications' private information has to be shared, which means that security breaches and illegal access to that information are real threats that have to be solved. Also mobile payment service is, one of the innovative services, has same issues which are real threats for users because mobile payment service sometimes requires user identification, an authentication procedure and confidential data sharing. Thus, an extra layer of security is needed in their communication and execution protocols. The Virtualization of Smart Cards (ViSCa), concept is a holistic approach and centralized management for a security system that pursues to provide a ubiquitous multi-device platform for the arrangement of mobile payment services that demand a powerful security protocol, both for the access & authentication and execution of its applications. In this sense, Virtualization of Smart Cards (ViSCa) offers full interoperability and full access from any user device without any loss of security. The concept prevents possible attacks by third parties, guaranteeing the confidentiality of personal data, bank accounts or private financial information. The Virtualization of Smart Cards (ViSCa) concept is split in two different phases: the execution of the user authentication protocol on the user device and the cloud architecture that executes the secure application. Thus, the secure service access is guaranteed at anytime, anywhere and through any device supporting previously required security mechanisms. The security level is improved by using virtualization technology in the cloud. This virtualization technology is used terminal virtualization to virtualize smart card hardware and thrive to manage virtualized smart cards as a whole, through mobile cloud technology in Virtualization of Smart Cards (ViSCa) platform-based mobile payment service. This entire process is referred to as Smart Card as a Service (SCaaS). Virtualization of Smart Cards (ViSCa) platform-based mobile payment service virtualizes smart card, which is used as payment mean, and loads it in to the mobile cloud. Authentication takes place through application and helps log on to mobile cloud and chooses one of virtualized smart card as a payment method. To decide the scope of the research, which is comparing Virtualization of Smart Cards (ViSCa) platform-based mobile payment service with other similar cases, we categorized the prior researches' mobile payment service groups into distinct feature and service type. Both groups store credit card's data in the mobile device and settle the payment process at the offline market. By the location where the electronic financial transaction information (data) is stored, the groups can be categorized into two main service types. First is "App Method" which loads the data in the server connected to the application. Second "Mobile Card Method" stores its data in the Integrated Circuit (IC) chip, which holds financial transaction data, which is inbuilt in the mobile device secure element (SE). Through prior researches on accept factors of mobile payment service and its market environment, we came up with six key factors of comparative analysis which are economic, generality, security, convenience(ease of use), applicability and efficiency. Within the chosen group, we compared and analyzed the selected cases and Virtualization of Smart Cards (ViSCa) platform-based mobile payment service.

Role of Balloon Guide Catheter in Modern Endovascular Thrombectomy

  • Chueh, Ju-Yu;Kang, Dong-Hun;Kim, Byung Moon;Gounis, Matthew J.
    • Journal of Korean Neurosurgical Society
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    • v.63 no.1
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    • pp.14-25
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    • 2020
  • Proximal flow control achieved with a balloon guide catheter (BGC) during endovascular treatment of acute ischemic stroke is reviewed in this article. In clinical practice, BGCs offer a multi-faceted approach for clot retrieval by creating proximal flow arrest, reducing embolic burden, and shortening procedure time. Evaluation of frontline thrombectomy procedures with BGCs revealed advantages of combined use over the conventional guide catheter (CGC), notably in the significant reduction of distal emboli to both the affected and previously unaffected territories. Recently, new measures of early and complete reperfusion at first thrombectomy pass have been identified as independent predictors of improved outcomes, which were consistently demonstrated with use of BGC as a safe and effective option to minimize number of passes during intervention. Prior randomized controlled trials reported the positive correlation between BGC-treated patients and a lower risk of mortality as well as shortened procedure time. While BGC use is more common in stent retriever-mediated mechanical thrombectomy, preliminary data has shown the potential benefit of device application during contact aspiration thrombectomy to achieve successful recanalization. However, the question of which major endovascular strategy reigns superior as a frontline remains to be answered. Along with clinical case assessments, BGC performance during in-vitro simulation was analyzed to further understand mechanisms for optimization of thrombectomy technique.