• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.302-309
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• 2009

We fabricated a Si nano floating gate memory with Schottky barrier tunneling transistor structure. The device was consisted of Schottky barriers of Er-silicide at source/drain and Si nanoclusters in the gate stack formed by LPCVD-digital gas feeding method. Transistor operations due to the Schottky barrier tunneling were observed under small gate bias < 2V. The nonvolatile memory properties were investigated by measuring the threshold voltage shift along the gate bias voltage and time. We obtained the 10/50 mseconds for write/erase times and the memory window of $\sim5V$ under ${\pm}20\;V$ write/erase voltages. However, the memory window decreased to 0.4V after 104seconds, which was attributed to the Er-related defects in the tunneling oxide layer. Good write/erase endurance was maintained until $10^3$ write/erase times. However, the threshold voltages moved upward, and the memory window became small after more write/erase operations. Defects in the LPCVD control oxide were discussed for the endurance results. The experimental results point to the possibility of a Si nano floating gate memory with Schottky barrier tunneling transistor structure for Si nanoscale nonvolatile memory device.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.16-21
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• 2017

In this paper, a Small-sized and planer resonator design of Magnetic Resonance - Wireless Power Transfer(MR-WPT) were proposed for practical applications of mobile devices, such as a laptop, a smart-phone and a tablet pc. The proposed MR-WPT system were based on four coil MR-WPT and designed as a transmitter part (Tx) and a receiver part (Rx) both are the same shape with the same loop and resonator. There are four different spiral coil type of resonators with variable of line length, width, gap and turns in $50mm{\times}50mm$ size. The both of top and bottom side of substrate(acrylic; ${\varepsilon}_r=2.56$, tan ${\delta}=0.008$) ere used to generate high inductance and capacitance in limited small volume. Loops were designed on the same plane of resonator to reduce their volume, and there are three different size. The proposed MR-WPT system were fabricated with two acrylic substrate plane of Tx and Rx each, the Rx and Tx loops and resonators were fabricated of copper sheets. There are 12 combinations of 3 loops and 4 resonators, each combination were measured to calculate transfer efficiency and resonance frequency in transfer distance from 1cm to 5cm. The measured results, the highest transfer efficiency was about 70%, and average transfer efficiency was 40%, on the resonance frequency was about 6.78 MHz, which is standard band by A4WP. We proposed small-sized and planer resonator of MR-WPT and showed possibility of mobile applications for small devices.

• Fire Science and Engineering
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• v.34 no.2
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• pp.14-21
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• 2020

This paper presents the study of a fire risk to the backside of two miniatures of ISO 9705 2/5 using a lightweight partition for indoor space division and reproduction of the ISO 9705 test. An SGP partition, stud partition, glass wool panel, urethane foam panel, sandwich panel, and glass partition were selected as the test specimens, which are frequently used in construction. According to the ISO 9705 test standard, stabilization was achieved using a measuring device that recorded data before the ignition of a burner and continued recording for 120 s thereafter. After ignition was achieved, the power was increased to 300 kW for 600 s and then reduced to 100 kW for 600 s. The specimens were subsequently observed for 180 s, and the fire risk to the backside and the fire pattern of the wall unit were analyzed. Owing to the amount of heat generated by the ignition source, the maximum temperature of the backside was observed to be 67.7 ℃ for the SGP partition, 55.1 ℃ for the stud partition, 52.4 ℃ for the glass wool panel, 727.4 ℃ for the sandwich panel, 561 ℃ for the urethane foam panel, and 630.5 ℃ for the glass partition. In the cases of the sandwich and urethane foam panels, the explosion of flammable gas occurred by virtue of fusion of the interior materials. The reinforced glass was fractured owing to the temperature difference between the heat- and nonheat-responsive parts. Ultimately, the fire risk to the nearby section room was deemed to be high.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.2
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• pp.61-65
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• 2009

In this paper, we report on the growth and optical characteristics of white-LED without fluorescent material. The growth of DH(double heterostructure) with AlGaN active layer was performed on a n-GaN/(0001) $Al_{2}O_{3}$ by the mixed-source HVPE and multi-sliding boat. The CRI(color rendering index) of packaging device charged in the range 72-93 with CIE chromaticity coordinates(x=$0.26{\sim}0.34$, y=$0.31{\sim}0.40$). And CCT(correlated color temperature) values was measured $5126{\sim}10406K$ with increasing injection current. The CIE point of conventional phosphor white LED shifts blue region, but cm point of non-phosphor white LED shifts opposite direction. These results show the mixed-source HVPE can be possible to newly fabricate method of phosphor free white LED with high CRI value.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.441-448
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• 2010

In the aging society, the walking assist robot is a necessary device for being able to help the older and the lower limb disabled people to walk. In order to produce a convenient robot for the older and the lower limb disabled, it is needed for the research to detect the implicit walking intention and to control robot by a user's intention. This study is a previous study to develop the detection model of the walking intention and analyze the user's walking intention while a person is walking with Lofstrand crutches, by the combination of FSR and tilt signals. The FSR sensors attached user's the palm and the soles of foot are sensing force/pressure signals from these areas and are used for detecting the walking intention and states. The tilt sensor acquires roll and pitch signal from area of vertebrae lumbales and reflects the pose of the upper limb. We can recognize the user's walking intention such as 'start walking', 'start of right or left foot forward', and 'stop walking' by the combination of FSR and tilt signals can recognize.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.125-132
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• 2006

The PET/CT scanner is an evolution in image technology. The two modalities are complementary with CT and PET images. The PET scan images are well known as low resolution anatomic landmak, but such problems may help with interpretation detailed anatomic framework such as that provided by CT scan. PET/CT offers some advantages-improved lesion localization and identification, more accurate tumor staging. etc. Conventional PET employs tranmission scan require around 4 min./bed position and 30 min. for whole body scan. But PET/CT scanner can reduced by 50% in whole body scan. Especially nowadays PET scanner LSO scintillator-based from BGO without septa and operate in 3-D acquisition mode with multidetectors CT. PET/CT scanner fusion problems solved through hardware rather than software. Such device provides with the capability to acquire accurately aligned anatomic and functional images from single scan. It is very important to effective detection from gamma ray source in PETdetector. And can be offer high quality diagnostic images. So we have study about detection processing of PET detector and high quality imaging process.

• The Journal of Society for e-Business Studies
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• v.25 no.2
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• pp.127-146
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• 2020

Overseas advanced countries are aware of the importance of research equipment and are providing a lot of policy support to revitalize the research equipment industry. However, Korea does not have any law to support policies or related projects to revitalize the research equipment industry. Therefore, there is an urgent need for legislation to support policies and projects for revitalizing research equipment industry. It is considered necessary to establish a separate special law for revitalizing the research equipment industry so that it can gain competitiveness in the global market of the research equipment industry. As we have seen, the necessary articles in the relevant laws should be specified so that various promotion policies can be developed to foster the research equipment industry. In order to promote the development of research equipment industry, there are three essential items to be specified in the law. First is research and development support, second is infrastructure development, and third is business incubation. The following contents should be included in each contents. First of all, "research and development support" includes research and envelopment project promotion and support policy items, research equipment development trends and investment trends, joint research between industry, academia, And research and development support for fusion, hybrid and commercialization. Next, the items to be included in "infrastructure development" should include the establishment of research equipment clusters, related support items, training of professional manpower, and research equipment development base area and institutions. Finally, the items that should be included in "business incubation." include support matters for the development of excellent companies (priority purchase system, etc.), matters related to technology transfer and marketing, matters concerning the protection of intellectual property, And matters for promoting overseas expansion.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.414-420
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• 2018

The digital convergence looking for new ways to engage visitors by superimposing virtual content on projection over the real world captured media contents. This paper propose the Light ID based interactive 3D immersive exhibition things view using HMD AR technology. This approach does not required to add any additional infrastructure to be built-in to enable service and uses the installed Lighting or displays devices in the exhibit area. In this approach, the Light ID can be used as a Location Identifier and communication medium to access the content unlike the QR Tag which supports provide the download information through web interface. This utilize the advantages of camera based optical wireless communication (OWC) to receive the media content on smart device to deliver immersive 3D content visualization using AR. The proposed exhibition method is emulated on GALAXY S8 smart phone and the visual performance is evaluated for Jeonju Hanok Village. The experimental results shows that the proposed method can give immersive 3D view for exhibit things in real-time.

• Cartoon and Animation Studies
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• s.48
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• pp.117-139
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• 2017

The possibility of interactivity of digital media environment is adopted in human expression system and integrates the dynamic aspect of digital technology with expressive structure, thereby transforming the paradigm of image acceptance as well as image expression range. Virtual reality images have an important meaning in that they are changing the one-way mechanism of production and acceptance of images that lead to producers-video-audiences beyond the problem of verisimilitude such as how vividly they simulate reality. First of all, the virtual reality image is not one-sided but interactive image composed by the user. Viewing a virtual reality image does not just see the camera shine, but it gets the same view as in the real world. Therefore, the image that was controlled through framing changes to be configured positively by the user. This implies a change in the paradigm of image acceptance as well as a change in the existing form of the image itself. In addition, the narrative structure of the image and the subjects that are formed in the process are also required to be discussed. In the virtual reality image, the user 's gaze is a fusion of the gaze inside the image and the gaze outside the image. This is because the position of the user as the subject of the gaze in the virtual reality image is continuously restricted by the device of the discourse such as the editing and the narration of the shot. The significance of the virtual reality image is not aesthetically perfect but it is reconstructed according to the user to reflect the existence of the user positively and engage the user in the image.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.156-157
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• 2012

단일 셀에서 비휘발성 및 고속의 휘발성 메모리를 모두 구동할 수 있는 다기능 메모리는 모바일 기기 및 embedded 장치의 폭발적인 성장에 있어 그 중요성이 커지고 있다. 따라서 최근 이러한 fusion기술을 응용한 unified RAM (URAM)과 같은 다기능 메모리의 연구가 주목 받고 있다. 이러한 다목적 메모리는 주로 silicon on insulator (SOI)기반의 1T-DRAM과 SONOS기술 기반의 비휘발성 메모리의 조합으로 이루어진다. 하지만 이런 다기능 메모리는 주로 단결정기반의 SOI wafer 위에서 구현되기 때문에 값이 비싸고 사용범위도 제한되어 있다. 따라서 이러한 다기능메모리를 다결정 실리콘을 이용하여 제작한다면 기판에 자유롭게 메모리 적용이 가능하고 추후 3차원 적층형 소자의 구현도 가능하기 때문에 다결정실리콘 기반의 메모리 구현은 필수적이라고 할 수 있겠다. 본 연구에서는 다결정실리콘을 이용한 channel recessed구조의 다기능메모리를 제작하였으며 각 1T-DRAM 및 NVM동작에 따른 memory 특성을 살펴보았다. 실험에 사용된 기판은 상부 비정질실리콘 100 nm, 매몰산화층 200 nm의 SOI구조의 기판을 이용하였으며 고상결정화 방법을 이용하여 $600^{\circ}C$ 24시간 열처리를 통해 결정화 시켰다. N+ poly Si을 이용하여 source/drain을 제작하였으며 RIE시스템을 이용하여 recessed channel을 형성하였다. 상부 ONO게이트 절연막은 rf sputter를 이용하여 각각 5/10/5 nm 증착하였다. $950^{\circ}C$ N2/O2 분위기에서 30초간 급속열처리를 진행하여 source/drain을 활성화 하였다. 계면상태 개선을 위해 $450^{\circ}C$ 2% H2/N2 분위기에서 30분간 열처리를 진행하였다. 제작된 Poly Si MFM에서 2.3V, 350mV/dec의 문턱전압과 subthreshold swing을 확인할 수 있었다. Nonvolatile memory mode는 FN tunneling, high-speed 1T-DRAM mode에서는 impact ionization을 이용하여 쓰기/소거 작업을 실시하였다. NVM 모드의 경우 약 2V의 memory window를 확보할 수 있었으며 $85^{\circ}C$에서의 retention 측정시에도 10년 후 약 0.9V의 memory window를 확보할 수 있었다. 1T-DRAM 모드의 경우에는 약 $30{\mu}s$의 retention과 $5{\mu}A$의 sensing margin을 확보할 수 있었다. 차후 engineered tunnel barrier기술이나 엑시머레이저를 이용한 결정화 방법을 적용한다면 device의 특성향상을 기대할 수 있을 것이다. 본 논문에서는 다결정실리콘을 이용한 다기능메모리를 제작 및 메모리 특성을 평가하였다. 제작된 소자의 단일 셀 내에서 NVM동작과 1T-DRAM동작이 모두 가능한 것을 확인할 수 있었다. 다결정실리콘의 특성상 단결정 SOI기반의 다기능 메모리에 비해 낮은 특성을 보여주었으나 이는 결정화방법, high-k절연막 적용 및 engineered tunnel barrier를 적용함으로써 해결 가능하다고 생각된다. 또한 sputter를 이용하여 저온증착된 O/N/O layer에서의 P/E특성을 확인함으로써 glass위에서의 MFM구현의 가능성도 확인할 수 있었으며, 차후 system on panel (SOP)적용도 가능할 것이라고 생각된다.