• International Journal of Knowledge Content Development & Technology
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• v.11 no.2
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• pp.7-21
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• 2021

The study was a descriptive cross-sectional survey which investigated the reading preferences of secondary school students in Nigeria during the lockdown occasioned by COVID-19 pandemic. A hundred secondary school students in Ile- Ife and Ilesa in Osun State, Nigeria were the study respondents. Close ended self-administered questionnaire was used to obtain data. Of the one hundred questionnaire which were applied to the study respondents, ninety-three were retrieved. Data obtained were analyzed using simple frequencies and percentages. The study established that majority of respondents were not pressured to read but read for pleasure. Preference for a wide range of fiction and non-fiction books which was read for purposes ranging from academic, social, relaxation and information was indicated by respondents. Availability of reading materials determined reading preference of majority of respondents as many could not afford to access electronic books whether free or not. The researchers recommended that different types of reading materials that suit the reading preferences and meet the diverse purpose of reading should be provided for the secondary school students during lockdown to improve their reading habits. Public libraries should function during this lock down period within the guidelines of the appropriate health authorities, while school libraries should be equipped to offer virtual services during the lockdown and the students should be exposed to e-books for their reading pleasure.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.5
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• pp.459-464
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• 2013

A reset-free anti-harmonic programmable multiplying delay-locked loop (MDLL) that provides flexible integer clock multiplication for high performance clocking applications is presented. The proposed MDLL removes harmonic locking problems by utilizing a simple harmonic lock detector and control logic, which allows this MDLL to change the input clock frequency and multiplication factor during operation without the use of start-up circuitry and external reset. A programmable voltage controlled delay line (VCDL) is utilized to achieve a wide operating frequency range from 80 MHz to 1.2 GHz with a multiplication factor of 4, 5, 8, 10, 16 and 20. This MDLL achieves a measured peak-to-peak jitter of 20 ps at 1.2 GHz.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.45-45
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• 1991

We describe a simple method for obtaining a narrow dip with subnatural linewidth in Doppler-free laser spectroscopy. The method is based on detecting the absolute magnitude, ｜Re[$\chi$NL($\omega$-$\omega$o)]｜, of the dispersive component (real part) of the nonlinear susceptibility induced by the pump beam, and the line shape recorded therefore exhibits a fully resolved technique and a dual phase lock-in amplifier, we have demonstrated the dip as narrow as 3 MHz in the laser-induced birefringence spectrum of the Na D1 line (natural linewidth 10 MHz). Possible spectroscopic applications are considered.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.848-854
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• 2012

We have studied the oligomerization of a fibril-forming segment of ${\alpha}$-Synulcein using a replica exchange molecular dynamics (REMD) simulation. The simulation was performed with trimers and tetramers of a 12 amino acid residue stretch (residues 71-82) of ${\alpha}$-Synulcein. From extensive REMD simulations, we observed the spontaneous formation of both trimer and tetramer, demonstrating the self-aggregating and fibril-forming properties of the peptides. Secondary structure profile and clustering analysis illustrated that antiparallel ${\beta}$-sheet structures are major species corresponding to the global free energy minimum. As the size of the oligomer increases from a dimer to a tetramer, conformational stability is increased. We examined the evolution of simple order parameters and their free energy profiles to identify the process of aggregation. It was found that the degree of aggregation increased as time passed. Tetramer formation was slower than trimer formation and a transition in order parameters was observed, indicating the full development of tetramer conformation which is more stable than that of the trimer. The shape of free energy surface and change of order parameter distributions indicate that the oligomer formation follows a dock-and-lock process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.882-890
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• 2009

In this paper, we describe a compensation method that can be used for the situation where Loran receivers lose their phase lock to the received Loran signals when Loran signals are employed for the synchronization of national infrastructures such as telecommunication networks, electric power distribution and so on. In losing the phase lock to the received signals in a Loran receiver, the inner oscillator of the receiver starts free-running and the performance of the timing synchronization signals which are locked to the oscillator's phase is very severly degraded, so the timing accuracy under 1 us for a Primary Reference Clock (PRC) required in the International Telecommunications Union (ITU) G.811 standard can not be satisfied in the situation. Therefore, in this paper, we propose a method which can compensate the phase jump by using a compensation algorithm when a Loran receiver loses its phase lock and the performance evaluation of the proposed algorithm is achieved by the Maximum Time Interval Error (MTIE) of the measured data. From the performance evaluation results, it is observed that the requirement under 1 us for a PRC can be easily achieved by using the proposed algorithm showing about 0.6 us with under 30 minutes mean interval of smoothing with 1 hour period when the loss of phase lock occurs.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.217-229
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• 1990

The Applegate-Kennedy classification, the drawing of removable partial denture design using color coding, the selective tissue placement impression method in case of Class I and Class II removable partial dentures, the design of the swing lock attachment of an alternative approach to conventional removable partial denture, the design of the intracoronal or extracoronal attachment, and the removable partial denture design using a rotational path were presented. The following conclusions from the above things were presented : 1. The swing lock attachment removable partial denture can be effective to an alternative approach when the design of conventional removable partial denture is improper with markedly mobile remaining teeth or missing key abutments. 2. Intracoronal or extracoronal attachments must be selected care-fully considering the conditions of the abutment teeth and alveolar ridge whether more occlusal loads to the abutment teeth or to the alveolar ridge are distributed. 3. It must be almost prerequisite that a functional impression is taken in case of Class I and class II removable partial dentures and in case of tooth-borne removable partial dentures, a removable partial denture using rotational path is strong, hygienic, esthetic, and can be accomplished successfully in the clinical aspect when it is properly designed and fabricated through the complete understanding of an indication and a principle. 4. All necessary informations must be achieved with carefully investigated surveying procedure according to each clinical case by Applegate-Kennedy classification which can be helpful and useful in the clinical application and it is important that dentists themselves must be in the habit of drawing a reasonable partial denture design using a color coding in the paper sheet.

• Wind and Structures
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• v.2 no.4
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• pp.285-303
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• 1999

A discrete vortex method (DVM) has been developed at the Department of Aerospace Engineering, University of Glasgow, to predict unsteady, incompressible, separated flows around closed bodies. The basis of the method is the discretisation of the vorticity field, rather than the velocity field, into a series of vortex particles that are free to move in the flow. This paper gives a brief description of the method and presents the results of calculations on static and transversely oscillating square section cylinders. The results demonstrate that the method successfully predicts the character of the flow field at different angles of incidence for the static case. Vortex lock-in around the resonance point is successfully captured in the oscillatory cases. It is concluded that the vortex method results show good agreement, both qualitatively and quantitatively, with results from various experimental data.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.83-89
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• 2016

Internet of Things (IoT) is widely used for biomechanics in sports activities and AHRS(Attitude and Heading Reference System) is a more cost effective solution than conventional high-grade IMUs (Inertial Measurement Units) that only integrate gyroscopes. In this paper, we attach the AHRS to the snowboard to measure the motion data like Air To Fakie, Caballerial and Free Style. In order to reduce the measurement error, we have adopted the sensors equipped with Kalman filtering and also used Euler angle to quaternion conversion to reduce the Gimbal-lock effect. We have tested and evaluated the accuracy and execution time of the pattern recognition algorithms like PCA, ICA, LDA, SVM to show the recognition possibility of it on the basic motions of Snowboarding from the 9-axis trajectory information which is gathered from AHRS sensor. With the result, PCA, ICA have low accuracy, but SVM have good accuracy to use for recognition of basic motions of Snowboarding.

• Journal of Korea Game Society
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• v.20 no.5
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• pp.89-98
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• 2020

In MMO game servers, NUMA (Non-Uniform Memory Access) architecture is generally used to achieve high performance. Furthermore, such servers normally use hash tables as internal data structure which have constant time complexity for insert, delete, and search operations. In this study, we proposed a concurrent hash table optimized for NUMA system to make MMO game servers improve their performance. We tested our hash table on 4 socket NUMA system, and the hash table shows at most 100% speedup over another high-performance hash table.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.173-175
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• 2005

Malfunction of Klippon relay in Cheju-Haenam HVDC system has been caused by the inflow of high voltage arc. In this paper, we have studied on the theoretical examination and data analysis of Klippon relay, and the countermeasures against the problems were suggested according to their causes. Grounding problem in Klippon relay is removed by one-point earth connection and by modification of grounding circuit. The effects of over current surge was removed by attaching blocking diodes by series In Klippon relay to remove surge input in Klippon relay's mercury contact. The problem of Induced overvoltage by 86re1ay excitation coil, was removed by attaching Free-wheeling diode in parallel with the excitation coil of Lock-out relay.