• Journal of the Korea Convergence Society
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• v.4 no.1
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• pp.21-26
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• 2013

Due to a lack of research regarding disruptive technologies in domestic research, the purpose of this study is to aid in the understanding of disruptive technologies through empirical analysis of cases selected in the computer data storage industry. Analysis results have shown that SSDs, which threaten the existence of HDDs, adhere to the conditions of being a disruptive technology as first presented by Christensen(1992). SSDs are not only technologically superior to HDDs but can be mass produced due to its applicability in a vast array of product categories made possible by their miniaturization, weight reduction, and safety. This diversity of applicable fields makes it possible for mass production leading to further decrease in the unit price ultimately continuing the diffusion of this technology. By presenting empirical cases to aid in the understanding of disruptive technology, it is determined that the findings of this study contribute greatly to both academia and the business world.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.461-466
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• 2012

This paper describes the development and test result of X-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels. S-band frequency is used for Telemetry & Command, and X-band frequency is used for mission data. Payload observations data in Mass Memory Unit (MMU) is modulated by QPSK modulator in X-band Transmitter, and then QPSK modulation signal is transmitted to antenna through transfer switch. In this Paper, we described the results of modulation, low-pass filter design, power amp development, and switch test. The FM XTU is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

• Structural Engineering and Mechanics
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• v.74 no.1
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• pp.129-143
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• 2020

This study proposes a new shape memory alloy-tuned mass damper (SMA-TMD) and investigates the effectiveness of this damper in reducing and controlling the vibrations of a transmission tower-line system under various seismic excitations. Based on a practical transmission line system and considering the geometric nonlinearity of this system, the finite element (FE) software ANSYS is used to create an FE model of the transmission tower-line system and simulate the proposed SMA-TMD. Additionally, the parameters of the SMA springs are optimized. The effectiveness of a conventional TMD and the proposed SMA-TMD in reducing and controlling the vibrations of the transmission tower-line system under seismic excitations is investigated. Moreover, the effects of the ground motion intensity and frequency ratio on the reduction ratio (η) of the SMA-TMD are studied. The vibration reduction effect of the SMA-TMD under various seismic excitations is superior to that of the conventional TMD. Changes in the ground motion intensity and frequency ratio have a significant impact on the η of the SMA-TMD. As the ground motion intensity and frequency ratio increase, the η values of the SMA-TMD first increase and then decrease. Studying the vibration reduction effects of the SMA-TMD can provide a reference for the practical engineering application of this damper.

• Analytical Science and Technology
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• v.7 no.1
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• pp.1-10
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• 1994

A survey was made on detection limit, reproducibility, matrix effect, linear dynamic range and the memory effect of yttrium and europium in order to analyze rare earth elements which exist as impurities in the rare earth oxide which is raw materials of fluorescent substance. When analysing a certain amount of thulium quantitatively using inductively coupled plasma mass spectrometry, it was found that the analysis was interfered with $EuO^+$ which is one of polyatomic ions caused by plasma. As the intensity of thulium linearly proportional to the europium concentration, it was possible to the determine the actual concentration of thulium.

• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.517-526
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• 2012

This study investigated the impact of individual differences in motivational reactivity on cognitive effort, memory strength (sensitivity) and decision making (criterion bias) in response to Internet ads with positive and negative content. Individual variation in trait motivational activation was measured using the Motivational Activation Measurement developed by A. Lang and her colleagues (A. Lang, Bradley, Sparks, & Lee, 2007). MAM indexes an individual's tendency to approach pleasant stimuli (ASA, Appetitive System Activation) and avoid unpleasant stimuli (DSA, Defensive System Activation). Results showed that individuals higher in ASA exert more cognitive effort during positive ads than individuals lower in ASA. Individuals higher in DSA exert more cognitive effort during negative ads compared to individuals lower in DSA. ASA did not predict recognition memory. However, individuals higher in DSA recognized ads better than those lower in DSA. The criterion bias data revealed participants higher in ASA had more conservative decision criterion, compared to participants lower in ASA. Individuals higher in DSA also showed more conservative decision criterion compared to individuals lower in DSA. The theoretical and practical implications are discussed.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1097-1104
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• 2002

Recently, with a drop in memory chip price and rapid development of mass storage memory chip technology, research on client-server Database Management Systems has gained wide attention. This Paper discusses the recovery technique in a page-server OODBMS environment. Although most researchers have studied client-server systems, the recovery technique has been a poor researches. In this paper, client transfers only the completed log records to the server and resolves the problems in the current recovery techniques. In addition, the server manages only the execution of completed log records suggesting a simple recover algorithm, Client uses system concurrency, fully, by acting to abort actions and it suggests a page unit recovery technique to reduce time that is required in the whole database.

• The Journal of Korea Robotics Society
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• v.16 no.4
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• pp.327-335
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• 2021

In this paper, we propose an embedded robot system based on "ROS2 on Yocto" that can support various robots. We developed a lightweight OS based on the Yocto Project as a next-generation robot platform targeting cloud robotics. Yocto Project was adopted for portability and scalability in both software and hardware, and ROS2 was adopted and optimized considering a low specification embedded hardware system. We developed SLAM, navigation, path planning, and motion for the proposed robot system validation. For verification of software packages, we applied it to home cleaning robot and indoor delivery robot that were already commercialized by LG Electronics and verified they can do autonomous driving, obstacle recognition, and avoidance driving. Memory usage and network I/O have been improved by applying the binary launch method based on shell and mmap application as opposed to the conventional Python method. Finally, we verified the possibility of mass production and commercialization of the proposed system through performance evaluation from CPU and memory perspective.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.53-58
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• 2023

The storage capacity of 3D-NAND flash memory has been enhanced by the multi-layer dielectrics. The deposition process has become more challenging due to the tight process margin and the demand for accurate process control. To reduce product costs and ensure successful processes, process diagnosis techniques incorporating artificial intelligence (AI) have been adopted in semiconductor manufacturing. Recently there is a growing interest in process diagnosis, and numerous studies have been conducted in this field. For higher model accuracy, various process and sensor data are required, such as optical emission spectroscopy (OES), quadrupole mass spectrometer (QMS), and equipment control state. Among them, OES is usually used for plasma diagnostic. However, OES data can be distorted by viewport contamination, leading to misunderstandings in plasma diagnosis. This issue is particularly emphasized in multi-dielectric deposition processes, such as oxide and nitride (ON) stack. Thus, it is crucial to understand the potential misunderstandings related to OES data distortion due to viewport contamination. This paper explores the potential for misunderstanding OES data due to data distortion in the ON stack process. It suggests the possibility of excessively evaluating process drift through comparisons with a QMS. This understanding can be utilized to develop diagnostic models and identify the effects of viewport contamination in ON stack processes.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2207-2212
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• 2012

Dimethylaluminum isopropoxide (DMAI, $(CH_3)_2AlO^iPr$) as a single precursor, which contains one aluminum and one oxygen atom, has been adopted to deposit non-stoichiometric aluminum oxide ($AlO_x$) films by low pressure metal organic chemical vapor deposition without an additional oxygen source. The atomic concentration of Al and O in the deposited $AlO_x$ film was measured to be Al:O = ~1:1.1 and any serious interfacial oxide layer between the film and Si substrate was not observed. Gaseous by-products monitored by quadruple mass spectrometry show that ${\beta}$-hydrogen elimination mechanism is mainly contributed to the $AlO_x$ CVD process of DMAI precursor. The current-voltage characteristics of the $AlO_x$ film in Au/$AlO_x$/Ir metalinsulator-metal (MIM) capacitor structure show high ON/OFF ratio larger than ${\sim}10^6$ with SET and RESET voltages of 2.7 and 0.8 V, respectively. Impedance spectra indicate that the switching and memory phenomena are based on the bulk-based origins, presumably the formation and rupture of filaments.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.414-416
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• 2003

As environmental conditions for memory products are increasingly high speed/high density, adopting diverse system configuration, it's more and more difficult for current component tester to adopt the actual condition of field application. If system test screening is realized in component level, test coverage failure can be made more secured in the initial stage, evaluation cost can be reduced and the effectiveness of investment for the facility can be maximized. Based on the above background, component automatic system tester was developed and showed off satisfactory results per each memory device family. In this paper, component quality stabilization strategy and cost saving for tester investment through future Quality monitoring and application to mass production will be presented.