• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.2
• /
• pp.297-301
• /
• 2001

In this paper, a system that transmits ECG signals which get from hand baggage ECG is implemented by using Bluetooth technology. Bluetooth technology is a close range wireless communication used wireless frequency 2.4GHz bandwidth. This technology consumes very small power and provides high reliability also self error correction with high speed frequency hopping. Because every device which uses Bluetooth protocol can communicate each other. These can connect between the system implemented and any devices such as mobile telephone with Bluetooth module, notebook, and the personal mobile device. Also, the paper proposes capability of transmission to the sever of hospital through each type of wireless communication device that acquired medical information signals in mobile medical machine. The system consists of hardware parts with Bluetooth module and host part, and software parts with blutooth protocol stacks. The host precesses a connection with other device and transmits ECG signals with bluetooth frequency hopping sequence.

• ETRI Journal
• /
• v.37 no.5
• /
• pp.877-887
• /
• 2015

This paper is a first-hand summary on our comprehensive live trial of cellular-assisted device-to-device (D2D) communications currently being ratified by the standards community for next-generation mobile broadband networks. In our test implementation, we employ a full-featured 3GPP LTE network deployment and augment it with all necessary support to provide realtime D2D connectivity over emerging Wi-Fi-Direct (WFD) technology. As a result, our LTE-assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real-world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE-assisted WFD solutions and associated operational ranges.

• Journal of the Semiconductor & Display Technology
• /
• v.11 no.3
• /
• pp.33-37
• /
• 2012

Simple and high efficiency blue organic light-emitting diodes with three organic layers of N, N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolylamino)-phenyl]-biphenyl-4,4'-diamine[DNTPD]/1,1-bis-(di-4-polya-minophenyl)cyclohexane[TAPC]/electron transport material [ET-137] were fabricated and their electroluminescent characteristics were evaluated according to the TAPC thickness variation in a range of $50{\sim}300{\AA}$. Electroluminescence spectra of the devices with structure of DNTPD/TAPC/ET-137 showed all the same central emission wavelengths of 455 nm under an applied voltage of 7V, which were similar with that of the device with ET-137 only. On the other hand, the electroluminescence spectra of the device with structure of DNTPD/ET-137 without TAPC layer showed double emission peaks at the wavelengths of 455 nm and 561 nm under an applied voltage of 7V. In the devices with structure of DNTPD/TAPC/ET-137, single peak blue emission was not maintained in the device with $50{\AA}$-thick TAPC above 8V by the formation of exciplex. In the device with $300{\AA}$-thick TAPC, however, single peak blue emission was maintained until 10 V. According to the thickness increase of TAPC in the fabricated devices, the current density and luminance decreased, but the luminous efficiency and roll-off characteristics were improved.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.2
• /
• pp.686-694
• /
• 2014

A power semiconductor device, usually used as a switch or rectifier, is very significant in the modern power industry. The power semiconductor, in terms of its physical properties, requires a high breakdown voltage to turn off, a low on-state resistance to reduce static loss, and a fast switching speed to reduce dynamic loss. Among those parameters, the breakdown voltage and on-state resistance rely on the doping concentration of the drift region in the power semiconductor, this effect can be more important for a higher voltage device. Although the low doping concentration in the drift region increases the breakdown voltage, the on-state resistance that is increased along with it makes the static loss characteristic deteriorate. On the other hand, although the high doping concentration in the drift region reduces on-state resistance, the breakdown voltage is decreased, which limits the scope of its applications. This addresses the fact that breakdown voltage and on-state resistance are in a trade-off relationship with a parameter of the doping concentration in the drift region. Such a trade-off relationship is a hindrance to the development of power semiconductor devices that have idealistic characteristics. In this study, a novel structure is proposed for the Insulated Gate Bipolar Transistor (IGBT) device that uses conductivity modulation, which makes it possible to increase the breakdown voltage without changing the on-state resistance through use of a P-floating layer. More specifically in the proposed IGBT structure, a P-floating layer was inserted into the drift region, which results in an alleviation of the trade-off relationship between the on-state resistance and the breakdown voltage. The increase of breakdown voltage in the proposed IGBT structure has been analyzed both theoretically and through simulations, and it is verified through measurement of actual samples.

• The Journal of the Korea Contents Association
• /
• v.19 no.7
• /
• pp.393-401
• /
• 2019

In this study, based on the general reasoning that the higher the resolution of the HMD, the greater the presence and immersion of the audience and the greater the presence experience, the difference in the presence experience according to the resolution of the virtual reality device is verified empirically Presence effect. To do this, 300 college students were included in the population, and VR simulations of the Oculus store were conducted using HMD and mobile devices with different resolutions (HD, FHD, WQHD) as stimuli. As a result, there was a significant difference in the presence experience of the audience according to the resolution of the mobile device attached to the virtual reality HMD, and the presence effect had a significant influence on the awakening. On the other hand, no significant influence was found in the effect of emotion. Therefore, we can prove a general reasoning hypothesis that the higher the resolution of the virtual reality device, the greater the presence experience of the audience. However, since the confounding effect and the impression are contradictory in the presence effect side, additional experiments research is required.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.3
• /
• pp.433-441
• /
• 2021

Android applications are released across various categories, including productivity apps and games, and users are exposed to various applications and even malware depending on their usage patterns. On the other hand, most analysis engines train using existing datasets and do not reflect user patterns even if periodic updates are made. Thus, the detection rate for known malware is high, while types of malware such as adware are difficult to detect. In addition, existing engines incur increased service provider costs due to the cost of server farm, and the user layer suffers from problems where availability and real-timeness are not guaranteed. To address these problems, we propose an analysis system that performs on-device malware detection through transfer learning, which requires only one-time communication with the server. In addition, The system has a complete process on the device, including decompiler, which can distribute the load of the server system. As an evaluation result, it shows 90.3% accuracy without transfer learning, while the model transferred with adware catergories shows 95.1% of accuracy, which is 4.8% higher compare to original model.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.12
• /
• pp.1871-1876
• /
• 2004

We demonstrate a novel fabrication technology for the microneedle array that can be used in the medical test field, which is transdermal drug delivery and blood analyte sampling. Previous researchers have used silicon-processed micromachining, a reactive ion etching, and molding techniques for the fabrication of microneedle array. However, these fabrication techniques have somewhat limitations apply to the microneedle array fabrication according to its application. Inclined LIGA process is suggested to overcome these problems. This process provides easier, sharper and longer out-of-plane microneedle array structure than conventional silicon-processed fabrication method did. Additionally, because of the advantage of the LIGA process based on mold fabrication for mass production, the polymer, PMMA(PolyMethylMethAcrylate), based microneedle array is useful as the mold base of nickel electroplating process; on the other hand, silicon-processed microneedle array is used in itself. In this research, we fabricate different types of out-of-plane microneedle array, which have different shape of tip, base and hole structure, using the inclined LIGA process. The fabricated microneedles have proper mechanical strength, height and sharpness to puncture human hand epidermis or dermis with less pain and without needle tip break during penetrating the skin.

• Journal of the Korea Computer Graphics Society
• /
• v.14 no.2
• /
• pp.1-8
• /
• 2008

This paper presents a design of a situation training system supporting mixed-reality for the developmental disabled. The training scenario is developed for the disabled to improve the sense of sight and perception. The user sticks a virtual pin into a hole in the working board according to the direction and the appropriate feedback is delivered based on the FSM(Finite State Machine). In order to improve the reality and the training effect, the user's hand is inserted in the virtual training environments and the tactile sensation is provided using the haptic device.

• Journal of Korea Multimedia Society
• /
• v.18 no.3
• /
• pp.401-407
• /
• 2015

In this paper, we propose the method to eliminate EMI (Electro-Magnetic Interference) in ELF (Extremely Low Frequency) band below 2 KHz for extending the gesture-recognition distance of smart TVs to more than 3m using electric potential sensor. First, we measure the electric field generated from the back panel of a TV and propose the effective arrangement of two sets of differential sensors as well as the shielding method using metal fiber. Also, we eliminate the PLN (Power Line Noise) and other noise generated from the TV and sensors as well as surrounding environments using filters. Using the proposed EMI eliminating methods, we evaluate displacement ratio on measured signals according to distance between sensors and a moving hand. Experiment results show that our proposed method can extend the hand-gesture sensing distance using EPS (Electric Potential Sensor) up to more than 3m, which is enough to satisfy applicability of EPS based remote control to Smart TVs.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.2
• /
• pp.99-109
• /
• 2011

This paper presents implementation details of home appliance control system using personal communicator based on LN2440 single board computer, which recognizes hand-gesture of user, controls remote moving device such as mobile home server, robot etc. through delivery of proper control commands. Also, this paper includes details of design and implementation of home gateway and mobile home server. The implemented prototype can be utilized to develop various remote control system including a remote exploration robot, intelligent wheelchair based on general purpose embedded system.