• Journal of The Korean Association of Information Education
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• v.22 no.4
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• pp.457-471
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• 2018

This study examined student- and school-level background and ICT factors that affected PISA 2015 Collaborative Problem Solving (CPS) for Korean students (4863 students from 142 high schools). A two-level hierarchical linear model (HLM) was analyzed from the basic model (model 1) with no predictors to the final model (model 5) with all predictors. Results showed that first, gender, socioeconomic/cultural backgrounds, cooperation level positively predicted CPS scores while perceived unfairness of teacher negatively predicted the outcome. Second, the more frequently ICT was used for out-of-school learning purposes, the less frequently ICT was used for entertainment purposes, and the less frequently ICT was used in schools, the higher CPS scores were. Considering ICT autonomy and social interaction variables measured for the first time in PISA 2015, students who were more interested in ICT and more autonomous in using ICT devices achieved higher CPS scores. On the other hand, the more students considered ICT important as social interaction, the less they gained CPS scores. Third, in terms of school-level characteristics, the smaller the students behavior detrimental to learning, the higher the teachers perceived positive working environment, and the fewer the number of computers available per student, the higher CPS scores were. To facilitate computer-based collaborative problem-solving competence, it is important for students to have interest and autonomy in using ICT. In addition, the guidelines of ICT use and SW curriculum need to be established in order to increase the effectiveness of using ICT device in school.

• Journal of IKEEE
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• v.20 no.3
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• pp.220-225
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• 2016

In this paer, low on-resistance and high-power trench gate MOSFET (Metal-Oxide-Silicon Field Effect Transistor) incorporating current sensing FET (Field Effect Transistor) is proposed and evaluated. The trench gate power MOSFET was fabricated with $0.6{\mu}m$ trench width and $3.0{\mu}m$ cell pitch. Compared with the main switching MOSFET, the on-chip current sensing FET has the same device structure and geometry. In order to improve cell density and device reliability, self-aligned trench etching and hydrogen annealing techniques were performed. Moreover, maintaining low threshold voltage and simultaneously improving gate oxide relialility, the stacked gate oxide structure combining thermal and CVD (chemical vapor deposition) oxides was adopted. The on-resistance and breakdown voltage of the high density trench gate device were evaluated $24m{\Omega}$ and 100 V, respectively. The measured current sensing ratio and it's variation depending on the gate voltage were approximately 70:1 and less than 5.6 %.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.25-32
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• 2021

In this paper, the Magneto-Electric(ME) dipole array antenna with dual-polarization in the X-Band is proposed and it is implemented and measured. The proposed array antenna is composed of 32 single ME dipole antenna and a Teflon PCB. 1 × 1 ME dipole antenna is implemented dual-polarization by radiating vertical polarization and horizontal polarization from two pairs of radiators. 2-port feeding structures are realized by lamination process using LTCC. And, each port independently feeds the radiator through a Γ-shaped feeding strip with isolation between ports. The Teflon PCB used in the antenna array has a 4-layer structure, and 2-port is fed through the top and bottom layers. The λ_g/4 transformer is applied to the transmission line of the Teflon PCB for impedance matching of the arrayed antenna and the Teflon PCB, and the optimal parameters are obtained through simulation. The measured maximum antenna gains of port 1 was 18.2 dBi, Cross-pol was 1.0 dBi. And the measured maximum antenna gains of port 1 was 18.1 dBi, Cross-pol was 3.2 dBi.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.39-44
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• 2021

In this paper, two types of BPF(Band Pass Filter) which are hair-pin and interdigital have been designed for millimeter-wave application using two types of material which are LCP(Liquid Crystal Polymer) and PTFE(Polytetrafluoroethylene) and also, their performances such as bandwidth, insertion loss, and in-band flatness are compared. The proposed BPF are designed as third-order filters, and their pass band is from 26.5 GHz to 27.3 GHz. Interdigital BPF using PTFE substrate has most wide -3 dB S21 bandwidth of 7.8 GHz and hair-pin BPF using LCP substrate has most narrow -3 dB S21 bandwidth among the proposed four BPF. For in-band insertion loss, hair-pin BPF using PTFE substrate achieves low insertion loss better than -0.667 dB, and hair-pin BPF using LCP substrate exhibits relatively high insertion loss among the proposed four BPF better than -0.937 dB. However, the maximum difference in insertion loss performance among the proposed four BPF is 0.27 dB, which is too small to negligible. For in-band flatness, interdigital BPF using PTFE substrate shows greatest performance of 0.017 dB, and hair-pin BPF using LCP substrate exhibits the lowest performance of 0.07 dB. There are tiny difference in in-band flatness performance of 0.053 dB. As a results, it is considered that the BPF using LCP substrate can derive the performances similar to that of the BPF using PTFE substrate in Millimeter-wave band.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.21-27
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• 2022

Flexible pressure sensor was developed using low-cost conductive graphite as printed electronics. Flexible pressure sensors are attracting attention as materials to be used in future industries such as medical, games, and AI. As a result of evaluating various electromechanical properties of the printed electrode for flexible pressure sensors, it showed a constant resistance change rate in a maximum tensile rate of 20%, 30° tension/bending, and a simple pulse test. A more appropriate matrix pattern was designed by simulating the electrodes for which this verification was completed. Utilizing the Serpentine pattern, we utilized a process that allows simultaneous fabrication and encapsulation of the matrix pattern. One side of the printed graphite electrode was O₂ plasma surface treated to increase adhesive strength, rotated 90 times, and two electrodes were made into one through a lamination process. As a result of pasting the matrix pattern prepared in this way to the wrist pulse position of the human body and proceeding with the actual measurement, a constant rate of resistance change was shown regardless of gender.

• ETRI Journal
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• v.41 no.3
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• pp.396-407
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• 2019

Laser-assisted bonding (LAB) is an advanced technology in which a homogenized laser beam is selectively applied to a chip. Previous researches have demonstrated the feasibility of using a single-tier LAB process for 3D through-silicon via (TSV) integration with nonconductive paste (NCP), where each TSV die is bonded one at a time. A collective LAB process, where several TSV dies can be stacked simultaneously, is developed to improve the productivity while maintaining the reliability of the solder joints. A single-tier LAB process for 3D TSV integration with NCP is introduced for two different values of laser power, namely 100 W and 150 W. For the 100 W case, a maximum of three dies can be collectively stacked, whereas for the 150 W case, a total of six tiers can be simultaneously bonded. For the 100 W case, the intermetallic compound microstructure is a typical Cu-Sn phase system, whereas for the 150 W case, it is asymmetrical owing to a thermogradient across the solder joint. The collective LAB process can be realized through proper design of the bonding parameters such as laser power, time, and number of stacked dies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1249-1254
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• 2020

As the market for life friendly ICT (Information and Communication Technologies) services has grown up, high tech elevator with IoT (Internet of Things), a key area of the fourth industry, have become an indispensable part of life. Existing elevators are composed of up and down buttons to conveniently climb up and down high rise buildings, but there is a small inconvenience that everyone experiences depending on the characteristics of the user's composition, types of use, frequency, etc. Existing elevators are automatically closed if there are no people within the range of sensors, but they are inconvenient for the passengers with disabilities to carry luggage or to use. In this paper, the smart button, a hardware firmware device, was designed to relieve user inconvenience by opening the elevator for a certain period of time considering the boarding time of the passengers.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.67-75
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• 2020

In this paper, by applying LCP substrate, the capacitor and inductor are implemented with a variety of value that can be used in 35 GHz circuits. Depending on how to apply it to the circuit, it is required high value by designing the basic structures such as electrode capacitor and spiral inductor. However they are not available in high-frequency domain, because their SRF(Self-Resonant Frequency) is lower than the frequency of 35-GHz. By finding the limit, this paper devised classifying passive devices for the DC and the high-frequency domain. The basic structure is suitable for DC and microstrip λ/8 length stub structure can be used for high-frequency. The open and short stub structure operate as a capacitor and inductor respectively in the frequency of 35 GHz. If their impedance is known, it is possible to extract the value through the impedance-related equation. By producing with the permittivity 2.9 LCP substrate, the basic structure which are available in the DC constituted a library of capacitance of 1.12 to 13.9 pF and inductance of 0.96 to 4.69 nH, measured respectively. The stub structure available in the high-frequency domain were built libraries of capacitance of 0.07 to 2.88 pF and inductance of 0.34 to 1.27 nH, calculated respectively. The measurements have proven how to diversify value, so libraries can be built more variously. It is possible to integrate with the operation circuit of TRM(Transmit-Receive Module) for the frequency 35-GHz, it will be an alternative to the passive devices that can be properly utilized in the circuit.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.335-336
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• 2015

미래 유망 디바이스를 X-Device로 규정하고 국내외 미래예측보고서 분석 및 ICT, 뇌 공학, 디바이스 분야의 전문가 인터뷰를 통해, 1세대 X-Device로 마인드 디바이스(Mind Device)를 선정하였다. 마인드 디바이스는 뇌신경 탐지를 통해 인간의 의사를 읽어내고 생각만으로 표현 소통을 가능케 하는 디바이스로 정의된다. 미래 유망 디바이스에 대한 세부 예측 및 향후 기획을 위해, 마인드 디바이스 관련 R&D 진행현황 및 필요성을 살펴보고 예상 적용분야를 정리하였다.

• Journal of Korean Society of Rural Planning
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• v.30 no.1
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• pp.81-97
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• 2024

This study examines the effects of adopting Information and Communication Technology (ICT) in livestock farm management on farm sales revenue. Using the 2020 Census of Agriculture, Forestry, and Fisheries, a nationally representative data set constructed by Statistics Korea, this study focuses on a sample of 9,020 livestock farms in South Korea. We employ Propensity Score Matching (PSM) methods to address the potential selection bias between 2,076 farms that used ICT for livestock farm management and 6,944 farms that did not. The findings consistently show that the use of ICT significantly increases farm revenue, taking into account the selection bias. The utilization of ICT in livestock farms leads to a higher increase in sales revenue, particularly for farms with greater sales.