• Geomechanics and Engineering
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• v.29 no.3
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• pp.207-218
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• 2022

In submerged floating tunnels (SFTs), a next-generation maritime transportation infrastructure, the tunnel module floats in water due to buoyancy. For the effective and economical use of SFTs, connection with the ground is inevitable, but the stability of the shore connection is weak due to stress concentration caused by the displacement difference between the subsea bored tunnel and the SFT. The use of an elastic joint has been proposed as a solution to solve the stability problem, but it changes the dynamic characteristics of the SFT, such as natural frequency and mode shape. In this study, the finite element method (FEM) was used to simulate the elastic joints in shore connections, assuming that the ground is a hard rock without displacement. In addition, a small-scale model test was performed for FEM model validation. A parametric study was conducted on the resonance behavior such as the natural frequency change and velocity, stress, and reaction force distribution change of the SFT system by varying the joint stiffness under loading conditions of various frequencies and directions. The results indicated that the natural frequency of the SFT system increased as the stiffness of the elastic joint increased, and the risk of resonance was the highest in the low-frequency environment. Moreover, stress concentration was observed in both the SFT and the shore connection when resonance occurred in the vertical mode. The results of this study are expected to be utilized in the process of quantitative research such as designing elastic joints to prevent resonance in the future.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.11
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• pp.1593-1604
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• 2002

The purpose of the study were to find how the trend had an effect on a buying motivation, a selecting standard, a frequency of use, a purchase place of cosmetics, makeup and the distinctive quality of social strata of regarding a clothing shopping orientation. The subjects of investigation were the women in twenties who live in Seoul and Chonnam province. This study had been done from May to July 2001, and 660 questionnaires were used for analysis. The measuring tools used were the items of matters of preceding studies and developed ones by researchers on which questionnaires were prepared. Factor and cluster analysis and Duncan's multiple range test, ANOVA, x$^2$-test, frequency, and percentage as analysis methods were used through SPSS. The results of the study were as follows. The clothing shopping orientation divided five shopping orientations such as ostentatious style, enjoyable style, economical style, and prudent style, and an attachment style for special brands and shops. On the basis of this result, the groups 20's females were classified into low groups by the cluster analysis; economical shopping group, indifferent shopping group, conspicuous shopping group, and recreational shopping group. In the case of cosmetics purchasing motives, evaluation criteria of cosmetics, stores selection criteria were found according to shopping orientation subdivision, and there was the significant difference between the groups in frequency of use, a purchase place of cosmetics.

• Annual Conference on Human and Language Technology
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• 1999.10e
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• pp.351-358
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• 1999

Two experiments were conducted to investigate effects of word-frequency on semantic processing of Hangul. Stimuli were two syllable words, and exemplars and target words were different in the final consonant of the second syllable in the Exp 1 and in the final consonant of the first syllable in the Exp2. Exp 1 shows the results that subjects made more errors on low frequency target words and took longer times on high frequency exemplars than on controls. In Exp 2 subjects took longer times on high frequency examplar-low frequency target word conditions than on controls. These results support the predictions of dual process models and suggest that the use of phonological and visual information depends on word frequency. Phonological activation appears to be an optional rather than obligatory process.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.661-673
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• 2010

This paper presents recent developments in an extremely compact, wireless impedance sensor node (the WID3, $\underline{W}$ireless $\underline{I}$mpedance $\underline{D}$evice) for use in high-frequency impedance-based structural health monitoring (SHM), sensor diagnostics and validation, and low-frequency (< ~1 kHz) vibration data acquisition. The WID3 is equipped with an impedance chip that can resolve measurements up to 100 kHz, a frequency range ideal for many SHM applications. An integrated set of multiplexers allows the end user to monitor seven piezoelectric sensors from a single sensor node. The WID3 combines on-board processing using a microcontroller, data storage using flash memory, wireless communications capabilities, and a series of internal and external triggering options into a single package to realize a truly comprehensive, self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency analog-to-digital and digital-to-analog converters so that the same device can measure structural vibration data. The compact sensor node collects relatively low-frequency acceleration measurements to estimate natural frequencies and operational deflection shapes, as well as relatively high-frequency impedance measurements to detect structural damage. Experimental results with application to SHM, sensor diagnostics and low-frequency vibration data acquisition are presented.

• ETRI Journal
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• v.43 no.4
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• pp.702-716
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• 2021

This work proposes suitable network configurations for single frequency networks (SFNs) with ATSC 1.0 based on network coverage calculations and the laboratory multipath handling performance of commercial receivers. SFNs are widely used for delivering terrestrial digital television services because of their efficient use of the spectrum. In Mexico the analogue television transmissions switch-off occurred on 31 December 2016. Thus it is expected the adopted ATSC 1.0 system will be in force for the next several years despite the recent standardization of the ATSC 3.0 system. As ATSC 1.0 uses 8-VSB modulation the multipath handling capability of receivers is critical for the design of SFNs. The presented network planning results help develop technical normativity for implementing SFNs in Mexico and other countries that use ATSC 1.0. SFNs with transmitter separation up to 130 km are fully covered for outdoor reception mainly due to the directivity of the receiving antenna. Moreover for indoor reception at least 70% of an SFN coverage area can be achieved with a transmitter separation of up to 60 km depending on the radiated power and the transmitter antenna height.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.223-231
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• 2022

The application of computer software into the linguistic analysis of texts proves useful to arrive at concise and authentic results from large data texts. Based on this assumption, this paper employs a Computer-Aided Text Analysis (CATA) and a Critical Discourse Analysis (CDA) to explore the manipulative strategies of positive/negative presentation in Orwell's Animal Farm. More specifically, the paper attempts to explore the extent to which CATA software represented by the three variables of Frequency Distribution Analysis (FDA), Content Analysis (CA), and Key Word in Context (KWIC) incorporate with CDA decipher the manipulative purposes beyond positive presentation of selfness and negative presentation of otherness in the selected corpus. The analysis covers some CDA strategies, including justification, false statistics, and competency, for positive self-presentation; and accusation, criticism, and the use of ambiguous words for negative other-presentation. With the application of CATA, some words will be analyzed by showing their frequency distribution analysis as well as their contextual environment in the selected text to expose the extent to which they are employed as strategies of positive/negative presentation in the text under investigation. Findings show that CATA software contributes significantly to the linguistic analysis of large data texts. The paper recommends the use and application of the different CATA software in the stylistic and corpus linguistics studies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.979-986
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• 2016

At present, electric power industry around the world are being gradually changed to a new paradigm, such as electrical energy storage system, the wireless power transmission. Demand for ESS, the core technology of the new paradigm, has been growing worldwide. However, it is essential to estimate the optimal capacity of ESS facilities for frequency regulation because the benefit would be saturated in accordance with the investment moment and the increase of total invested capacity of ESS facilities. Hence, in this paper, the annual optimal mathematical investment model is proposed to estimate the optimal capacity and to establish investment plan of ESS facility for frequency regulation. The optimal mathematical investment model is newly established for each season, because the construction period is short and the operation effect for the load by seasons is different unlike previous the mathematical investment model. Additionally, the marginal operating cost is found by new mathematical operation model considering no-load cost and start-up cost as step functions improving the previous mathematical operation model. ESS optimal capacity is established by use value in use iterative methods. In this case, ESS facilities cost is used in terms of the value of the beginning of the year.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1543-1548
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• 2009

In this paper, a high speed code synchronization circuit is proposed. for fast code synchronization, matched filler method is used for initial code acquisition with two channel correlators. Particular frequency patterns of the limited number having the information about PN code start time are composed and transmitted repeatedly to increase the probability of accurate initial synchronization. And digital frequency synthesizer is proposed. And it's performance is analyzed theoretically. The analysis show that fast frequency hopping is possible in frequency hopping system that use digital frequency synthesizer.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.267-269
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• 2007

PLL(Phase Locked Loop) are widely used circuit technique in modern electronic systems. In this paper, We propose the low voltage and high speed PLL. We design the PFD(Phase Frequency Detector) by using TSPC (True Single Phase Clock) circuit to improve the performance and solve the dead-zone problem. We use CP(Charge Pump} and LP(Loop filter) for Negative feedback and current reusing in order to solve current mismatch and switch mismatch problem. The VCO(Voltage controlled Oscillator) with 5-stage differential ring oscillator is used to exact output frequency. The divider is implemented by using D-type flip flops asynchronous dividing. The frequency divider has a constant division ratio 32. The frequency range of VCO has from 200MHz to 1.1GHz and have 1.7GHz/v of voltage gain. The proposed PLL is designed by using 0.18um CMOS processor with 1.8V supply voltage. Oscillator's input frequency is 25MHz, VCO output frequency is 800MHz and lock time is 5us. It is evaluated by using cadence spectra RF tools.

• CELLMED
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• v.3 no.4
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• pp.29.1-29.11
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• 2013

Certain dietary contents, biological supplements might influence the occurrence or treatment of epilepsy. Some studies have found that the supplementation with individual nutrients reduced seizure frequency or improved other aspects of health in patients with epilepsy. Potentially beneficial dietary interventions include treating blood glucose dysregulations. Identifying and avoiding allergenic foods, and avoiding suspected triggering agents such as alcohol, aspartame, and monosodium glutamate. The Atkins diet (very low in carbohydrates) is a less restrictive type diet that may be effective in some cases. Nutrients that may reduce seizure frequency include vitamin B6, magnesium, vitamin E, manganese, taurine, dimethylglycine, and omega-3 fatty acids. Administration of thiamine may improve cognitive function in patients with epilepsy. Supplementation with folic acid, vitamin B6, biotin, vitamin D, and L-carnitine may be needed to prevent or treat deficiencies resulting from the use of anticonvulsant drugs. Vitamin K1 has been recommended near the end of pregnancy for women taking anticonvulsants. Melatonin may reduce seizure frequency in some cases, and progesterone may be useful for women with cyclic exacerbations of seizures. In most cases, nutritional therapy is not a substitute for anticonvulsant medications. However, in selected cases, depending on the effectiveness of the interventions, dosage reductions or discontinuation of medications may be possible. However, nutrient supplementation may be necessary to prevent or reverse the effects of certain deficiencies that frequently result from the use of antiepileptic drugs.