• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.148-153
• /
• 2022

In keeping with the fourth industrial revolution, IoT-based environments are being implemented everywhere, and as a result, there is an increasing number of cases in which various types of sensed data are utilized efficiently. In particular, the number of multimedia application cases using smart devices is increasing, and there is an increasing number of cases in which large amounts of data are used as fast and convenient as small amounts of data. Given the increasing size of files used in smart devices, the study designed a modified Htree based on journaling meta data management in Ext4-based smart devices and analyzed performance through experiments of various methods. Performance evaluation analysis using IOZone and Hdread shows that the data size of 100Mbyte compared to the data input / output of existing htree is 10% or more, and that of the super large capacity file of 500Mbyte or more is 5% or more.

• Korean Journal of Materials Research
• /
• v.32 no.8
• /
• pp.333-338
• /
• 2022

In this work, we developed silver nanowires and a silicon based Schottky junction and demonstrated ultrafast broadband photosensing behavior. The current device had a response speed that was ultrafast, with a rising time of 36 ㎲ and a falling time of 382 ㎲, and it had a high level of repeatability across a broad spectrum of wavelengths (λ = 365 to 940 nm). Furthermore, it exhibited excellent responsivity of 60 mA/W and a significant detectivity of 3.5 × 10¹² Jones at a λ = 940 nm with an intensity of 0.2 mW cm^-2 under zero bias operating voltage, which reflects a boost of 50 %, by using the AC PV effect. This excellent broadband performance was caused by the photon-induced alternative photocurrent effect, which changed the way the optoelectronics work. This innovative approach will open a second door to the potential design of a broadband ultrafast device for use in cutting-edge optoelectronics.

• Educational Technology International
• /
• v.24 no.2
• /
• pp.263-293
• /
• 2023

Offices of Education in Korea is planning and implementing the BYOD (bring your own device) policy. In particular, the Seoul Metropolitan Education Office promoted the 'Dibud' (digital buddy) policy. Due to the relative newness of the policy, coupled with opposition from the council, it hasn't been fully implemented. This study focuses on a rare example of a high school that experienced BYOD under the Office of Education-led policy in all three grades. This study adapted key variables from the Technology Acceptance Model (TAM). The regression results showed that both perceived usefulness (PU) and perceived ease of use (PEOU) significantly influenced intention to use Chromebooks and students' perceived learning outcomes. Analysis of the open-ended questionnaires revealed that students perceived positive benefits from using Chromebooks, such as easier data retrieval, improved academic performance, and increased learning productivity. Although the majority of respondents said there were no negative aspects to Chromebooks, negative factors included non-academic use, wireless network inconvenience, and device performance issues. The results of this study can provide data and understanding for future BYOD policies, specifically Chromebooks.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.4
• /
• pp.136-141
• /
• 2023

The continuous shrinking of transistors in integrated circuits leads to difficulties in improving performance, resulting in the emerging transistors such as nanosheet field-effect transistors. In this paper, we propose a TCAD-machine learning framework of nanosheet FETs to model the current-voltage characteristics. Sentaurus TCAD simulations of nanosheet FETs are performed to obtain a large amount of device data. A machine learning model of I-V characteristics is trained using the multi-layer perceptron from these TCAD data. The weights and biases obtained from multi-layer perceptron are implemented in a PSPICE netlist to verify the accuracy of I-V and the DC transfer characteristics of a CMOS inverter. It is found that the proposed machine learning model is applicable to the prediction of nanosheet field-effect transistors device and circuit performance.

• Transactions on Control, Automation and Systems Engineering
• /
• v.4 no.3
• /
• pp.212-216
• /
• 2002

A practical issue is studied to improve the performance of a new energy based method of achieving stable, high performance haptic interface control. The issue is related to resetting the amount of energy accumulated in the Passivity Observer for faster operation. A heuristic method is derived and experimentally tested for the resetting and it is shown to help the PC to operate sooner when the system gets active. Experimental results are presented for the “Excalibur” haptic device.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.111-113
• /
• 2006

FOUNDATION fieldbus provides scheduling and token-passing services for cyclic and sporadic data respectively. In this paper, we evaluate the delay performance of token-passing mechanism in FOUNDATION fieldbus network system using an experimental model. This paper introduces a method of developing an experimental model which consists of 10 nodes of FOUNDATION fieldbus communication device. Using the experimental model, we evaluate the delay performance of time-critical and time-available data with respect to change of TTRT parameter.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.241-244
• /
• 2002

Using disturbance observers is effective in enhancing the performance of systems in presence of disturbances. In this paper, we present a novel design of disturbance observers to achieve enhanced robust performance. In addition, we propose a new method of reducing the effect of measurement noise via modification of plant modeling in disturbance observer.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2009.02a
• /
• pp.77-77
• /
• 2009

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2000.10a
• /
• pp.85-89
• /
• 2000

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.101-101
• /
• 1998