• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.3
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• pp.240-250
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• 2010

Double Gate MOSFETs (DG MOSFETs) with doping in one or two thin layers of an otherwise intrinsic channel are simulated to obtain the transport characteristics, threshold voltage and leakage current. Two different device structures- one with doping on two layers near the top and bottom oxide layers and another with doping on a single layer at the centre- are simulated and the variation of device parameters with a change in doping concentration and doping layer thickness is studied. It is observed that an n-doped layer in the channel reduces the threshold voltage and increases the drive current, when compared with a device of undoped channel. The reduction in the threshold voltage and increase in the drain current are found to increase with the thickness and the level of doping of the layer. The leakage current is larger than that of an undoped channel, but less than that of a uniformly doped channel. For a channel with p-doped layer, the threshold voltage increases with the level of doping and the thickness of the layer, accompanied with a reduction in drain current. The devices with doped middle layers and doped gate layers show almost identical behavior, apart from the slight difference in the drive current. The doping level and the thickness of the layers can be used as a tool to adjust the threshold voltage of the device indicating the possibility of easy fabrication of ICs having FETs of different threshold voltages, and the rest of the channel, being intrinsic having high mobility, serves to maintain high drive current in comparison with a fully doped channel.

• Journal of Information Management
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• v.42 no.2
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• pp.121-149
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• 2011

The purpose of this study is to analyze influencing factors for the user satisfaction of information commons(IC) in school libraries. Relevant previous studies inform four candidate factors that could affect the user satisfaction. Based upon these factors and user interviews, a questionnaire are constructed to form 29 items in total. As the main data, 412 samples are collected from the IC users from 3 high schools in Seoul. Analyses lead to these findings: factors affecting the user satisfaction are identified. They are IC facilities, human services, and achievement level of self-directed learning. It seems that, in ICs, users prefer using space and facilities by themselves to accessing contents. This study suggests ways to improve user satisfaction. It would be essential to introduce IC facilities to current and potential users, to install instruments to enhance achievement level of self-directed learning, and to train users through library education programs.

• Transactions on Electrical and Electronic Materials
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• v.17 no.5
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• pp.280-288
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• 2016

Microelectronic product consumers may already be expecting another paradigm shift with smarter phones over smart phones, but the current status of microelectronic manufacturing engineering education (MMEE) in universities hardly makes up the pace for such a fast moving technology paradigm shift. The purpose of MMEE is to educate four-year university graduates to work in the microelectronics industry with up-to-date knowledge and self-motivation. In this paper, we present a comprehensive curriculum for a four-year university degree program in the area of microelectronics manufacturing. Three hands-on experienced-based courses are proposed, along with a methodology for undergraduate students to acquire hands-on experience, towards integrated circuits (ICs) design, fabrication and packaging, are presented in consideration of manufacturing engineering education. Semiconductor device and circuit design course for junior level is designed to cover how designed circuits progress to micro-fabrication by practicing full customization of the layout of digital circuits. Hands-on experienced-based semiconductor fabrication courses are composed to enhance students’ motivation to participate in self-motivated semiconductor fab activities by performing a series of collaborations. Finally, the Microelectronics Packaging course provides greater possibilities of mastered skillsets in the area of microelectronics manufacturing with the fabrication of printed circuit boards (PCBs) and board level assembly for microprocessor applications. The evaluation of the presented comprehensive curriculum was performed with a students’ survey. All the students responded with “Strongly Agree” or “Agree” for the manufacturing related courses. Through the development and application of the presented curriculum for the past six years, we are convinced that students’ confidence in obtaining their desired jobs or choosing higher degrees in the area of microelectronics manufacturing was increased. We confirmed that the hypothesis on the inclusion of handson experience-based courses for MMEE is beneficial to enhancing the motivation for learning.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.405-413
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• 2013

In this paper, a high-reliability differential paired 24-bit eFuse OTP memory with program-verify-read mode for PMICs is designed. In the proposed program-verify-read mode, the eFuse OTP memory can do a sensing margin test with a variable pull-up load in consideration of programmed eFuse resistance variation and can output a comparison result through a PFb (pass fail bar) pin by comparing a programmed datum with its read one. It is verified by simulation results that the sensing resistance is lower with $4k{\Omega}$ in case of the designed differential paired eFuse OTP memory than $50k{\Omega}$ in case of its dual-port eFuse OTP memory.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1299-1305
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• 2017

In this paper, we consider a beamforming game between the transmitters in a two-user multiple-input single-output interference channel using limited feedback and investigate how each transmitter is able to find a modified strategy from the quantized channel state information (CSI). In the beamforming game, each of the transmitters (i.e., a player) tries to maximize the achievable rate (i.e., a payoff function) via a proper beamforming strategy. In our case, each transmitter's beamforming strategy is represented by a linear combining factor between the maximum ratio transmission (MRT) and the zero forcing (ZF) beamforming vectors, which is the Pareto optimal achieving strategy. With the quantized CSI, the transmitters' strategies may not be valid because of the quantization errors. We propose a modified solution, which takes into account the effects of the quantization errors.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.439-445
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• 2007

SiGe integrated circuits are being used in the field of high-speed wire/wireless communications and microwave systems due to the RF/high-speed analog characteristics and the easiness in the fabrication. Reducing the resistance variation in SiGe thin film resistors results in enhancing the reliability of integrated circuits. In this paper, we investigate the causes that generate the resistance nonuniformity after the silicon-based thin film resistor was fabricated, and consider the counter plan against that. Because the Ti-B precipitate, which formed during the silicide process of the SiGe thin film resistor, gives rise to the nonuniformity of SiGe resistors, the boron ions should be implanted as many as possible. In addition, the resistance deviation increases as the size of the contact hole that interconnects the SiGe resistor and the metal line decreases. Therefore, the size of the contact hole must be enlarged in order to reduce the resistance deviation.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.8-13
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• 2000

A study was carried out to determine the probiotic effect of Lactobacillus reuteri BSA-131 by investigating the growth performance and fecal microbial population of piglets. Five dietary treatment groups, the basal diet (control, BD), basal diet with antibiotics(BA), basal diet with 2$\times$106/g of probiotics (BP6), 2$\times$108/g of probiotics (BP8) and basal diet with antibiotics and 2$\times$108/g probiot-ics(BAP8) were divised. Each dietary treatment group was consisted of 1 month of age piglets(male 13, female 12). Fecal micro-flora, body weights and feed consumption were measured at before, after and stop feeding of probiotics. The results showed that the CFU of fecal Enterobacteriaceae of piglets of the group BA, BP6, BP8 and BAP8, were reduced (P<0.05) compared to control BA. On the contrary, Lactobacillus counts were increased significan시 (P<0.001) in all groups fed probiotics dites, but not antibiotics. Body weight of probiotics treated piglets were improved 5% (p<0.001) in BP6 group than that of control group and antibiotic treated piglets BAP group was 27% (P<0.001) higher than BA group. The amount of feed consumption value of probiotics treated piglets showed 21-30% (P<0.001) lower intake than the control group, whereas antibiotic treated piglets BAP was 20% (P<0.001) higher than BA group. The results showed that body weights and feed to gain ratios were improves 19% when compared to control piglets for groups fed diets probiotic. It is very suggestive that productivity of probiotic piglets would be economical in pig farming.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.17-23
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• 2007

Long-term potentiation (LTP) of synaptic transmission is the most widely studied model for learning and memory. However its mechanisms are not clearly elucidated and are a subject for intense investigation. Previous attempts to decipher cellular mechanisms and network properties involved a current-source density analysis (CSDA) of the LTP from small animal hippocampus measured with a limited number of microelectrodes (typically <3), only revealing limited nature of spatiotemporal dynamics. Recent advancement in multi-electrode array (MEA) technology allows continuous and simultaneous recordings of LTP with more than 60 electrodes. However CSDA via the standard Laplacian transform is still limited due to its relatively high sensitivity toward noise, inability of resolving overlapped current sources and sinks, and its requirement for tissue conductivity values. In this study, we propose a new methodology for improved CSDA. Independent component analysis and its joint use (i.e., Joint-ICA) are applied to extract spatiotemporal components of LTP. The results show that ICA and Joint-ICA are capable of extracting independent spatiotemporal components of LTP generators. The ICs of LTP indicate the reversing roles of current sources and sinks which are associated with LTP.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.2
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• pp.19-27
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• 2008

Ecosystem fragmentation by human intervention breaks down the biosphere habitat. Wildlife corridors connect biosphere habitats to maintain ecosystem continuity and provide animals with connecting routes. In Korea, there are 17 existing wildlife corridors on highways (as of December, 2006. Korea Freeway Corporation). There are 24 highway routes, 2,923km of highway(as of December, 2004. Korea Freeway Corporation). However, wildlife corridors are not enough and roadkill increases every year, so we need to construct additional wildlife corridors on highways. This study proposes a new approach to the location of wildlife corridors on highways, using a comprehensive analysis method for main location elements, and applies it to a study area. First, it examines traditional approaches to location of wildlife corridors through literature review and field study to analyze the present conditions of existing wildlife corridors. Then, it developes a comprehensive analysis method for the location of wildlife corridors. (1) Field investigation : investigate planting, water bodies and so on. (2) Roadkill analysis : roadkill counts, locations, time, and so on. (3) Monitoring : animal traces were surveyed and sensor cameras were installed to determine target species. (4) Simulation for animal movement : most probable wildlife dispersal was simulated by a computer software. (5) A new comprehensive approach overlays all analysis on a map and determines the location of proposed new wildlife corridors. In conclusion, it proposes an over-bridge type wildlife corridor in Dalnaenae Hill (413-414km from Busan) and an underpass type near the entrance to Gwanhyun temple way (415-416km from Busan). This new approach based on roadkill data, computer simulation of wildlife dispersal, monitoring of animals, and site analysis, may contribute to better location of wildlife corridors on highways.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.310-318
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• 2015

In this paper, dual-port eFuse OTP (one-time programmable) memory cells with smaller cell sizes are used, a single VREF (reference voltage) is used in the designed eFuse OTP IP (intellectual property), and a BL (bit-line) sensing circuit using a S/A (sense amplifier) based D F/F is proposed. With this proposed sensing technique, the read current can be reduced to 3.887mA from 6.399mA. In addition, the sensing resistances of a programmed eFuse cell in the program-verify-read and read mode are also reduced to $9k{\Omega}$ and $5k{\Omega}$ due to the analog sensing. The layout size of the designed 32-bit eFuse OTP memory is $187.845{\mu}m{\times}113.180{\mu}m$ ($=0.0213{\mu}m2$), which is confirmed to be a small-area implementation.