• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1597-1604
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• 2020

In this study, a synthesized poly(amino acid) self-assembly grafted with valine molecules was investigated on the skin activity of skin growth factors. The amphiphilic grafted poly(amino acid) derivatives were successfully synthesized by varying of degree of substitution(DS) and polymerization (DP) with valine molecules forming a β-sheet structure. Then, the pro-collagen biosynthesis of EGF(epidermal growth factor) was improved by 20%, and the inhibitory ability of tyrosinase activity was increased by 6.5 times by self-assembling of EGF with the poly(amino acid)s having β-sheet structures. This strategy of preparing protein self-assembly with poly(amino acid) derivatives will help improve the stability of protein growth factors and use it in medicals as well as cosmeceuticals through skin improvement.

• Journal of IKEEE
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• v.25 no.4
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• pp.634-643
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• 2021

In this paper, an FPGA-based acceleration scheme of range Doppler algorithm (RDA) is proposed for the real time synthetic aperture radar (SAR) imaging. Hardware architectures of matched filter based on systolic array architecture and a high speed sinc interpolator to compensate range cell migration (RCM) are presented. In addition, the proposed hardware was implemented and accelerated on Xilinx Alveo FPGA. Experimental results for 4096×4096-size SAR imaging showed that FPGA-based implementation achieves 2 times acceleration compared to GPU-based design. It was also confirmed the proposed design can be implemented with 60,247 CLB LUTs, 103,728 CLB registers, 20 block RAM tiles and 592 DPSs at the operating frequency of 312 MHz.

• Journal of IKEEE
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• v.26 no.3
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• pp.333-340
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• 2022

Process and device simulations were performed to determine the optimal ion implantation conditions to prevent double snapback of high voltage operating DDDNMOS (double diffused drain N-type MOSFET) device for ESD protection. By examining the effects of HP-Well, N^- drift and N⁺ drain ion implantation on the double snapback and avalanche breakdown voltages, it was possible to prevent double snapback and improve the electrostatic protection performance. If the ion implantation concentration of the N^- drift region rather than the HP-Well region is optimally designed, it prevents the transition from the primary on-state to the secondary on-state, so that relatively good ESD protection performance can be obtained. Since the concentration of the N^- drift region affects the leakage current and the avalanche breakdown voltage, in the case of a process technology with an operating voltage greater than 30V, a new structure such as DPS or colligation of optimal process conditions can be applied. In this case, improved ESD protection performance can be realized.

• Journal of Oriental Neuropsychiatry
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• v.33 no.3
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• pp.277-285
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• 2022

Objectives: Gastrodia elata (GE) has been used to treat cognition impairment, including Alzheimer's disease (AD) in Korea. The purpose of this study was to investigate the effects of GE water extracts (GEE) on the lipopolysaccharide (LPS)-induced AD model in mice. (Aβ). Methods: We classified six groups as follow; group 1: control (CON), group 2: LPS (0.5 mg/kg/day, four times), group 3: 4 mg/kg donepezil (DP), group 4: 100 mg/kg GEE+LPS, group 5: 200 mg/kg GEE+LPS, group 6: 500 mg/kg GEE+LPS. Results: We found that GEE has an effect that inhibits decrease of discrimination index in object recognition test, as well as spontaneous alteration in the Y-maze test by LPS. Treatment with LPS increased amlyloid-β (Aβ) concentration, and decreased brain-derived neurotrophic factor (BDNF) in cerebral cortex of mice. However, GEE significantly protected against LPS-induced Aβ and BDNF changes. Our findings also showed that the inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β)] mRNA and protein were up-regulated by the LPS injection. But GEE significantly suppressed LPS-induced inflammatory cytokines increase in a dose-dependent manner. Conclusions: This study suggests that the GEE may be an effective AD therapeutic agent, in treating neurodegenerative diseases including AD.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.96-103
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• 2022

This paper presents the analysis of increasing the resolution of True-Time-Delay (TTD) by 0.5-bit for phased-array antenna system which is one of the Multiple-Input and Multiple Output (MIMO) technologies. For the analysis, a 5.5-bit True-Time Delay (TTD) integrated circuit is designed and analyzed in terms of beam steering performance. In order to increase the number of effective bits, the designed 5.5-bit TTD uses Single Pole Triple Throw (SP3T) and Double Pole Triple Throw (DP3T) switches, and this method can minimize the circuit area by inserting the minimum time delay of 0.5-bit. Furthermore, the circuit mostly maintains the performance of the circuit with the fully added bits. The idea of adding 0.5-bit is verified by analyzing the relation between the number of bits and array elements. The 5.5-bit TTD is designed using 0.18 ㎛ RF CMOS process and the estimated size of the designed circuit excluding the pad is 0.57×1.53 mm². In contrast to the conventional phase shifter which has distortion of scanning angle known as beam squint phenomenon, the proposed TTD circuit has constant time delays for all states across a wide frequency range of 4 - 20 GHz with minimized power consumption. The minimum time delay is designed to have 1.1 ps and 2.2 ps for the 0.5-bit option and the normal 1-bit option, respectively. A simulation for beam patterns where the 10 phased-array antenna is assumed at 10 GHz confirms that the 0.5-bit concept suppresses the pointing error and the relative power error by up to 1.5 degrees and 80 mW, respectively, compared to the conventional 5-bit TTD circuit.

• Lettere Italiane
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• no.30
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• pp.205-229
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• 2010

L'italiano ha diverse forme di pronomi clitici che vengono distinti in genere, numero e persona a seconda del nome di partenza. Quando appare un pronome clitico, l'ordine delle parole nella frase cambia: dal tipo normale SVO si passa al tipo SOV come in coreano. I pronomi clitici hanno una caratteristica molto diversa rispetto sia a piena NP sia ad una NP debole, e non sono compatibili con questi NP all'interno della frase, il che significa che i pronomi clitici si muovono in posizione superficiale lasciando la loro posizione originale dopo il verbo. Osservando questo fenomeno (movimento clitico da [DP, VP] a [spec, AgrOP]) e analizzando in questa sede solo il caso del pronome diretto si è cercato di evidenziare le regole precise di tale movimento determinato da "Case licensing" e "feature checking." Seguendo e accettando pienamente la precedente analisi di Belletti(1999), in cui vengono proposte due vie di procedimento del movimento dentro il AgrOP (una è [spec, AgrOP]; l'altra, [Agro, AgrOP], propongo qui l'esistenza di un ordine preciso in tale movimento: nel caso in cui un pronome diretto prenda una via di [spec, AgrOP], 'V' si muove prima fino ad arrivare alla [Agro, AgrSP], poi, 'pro' prosegue la sua strada fino alla [pro, AgrSP], e alla fine, il pronome diretto sale fino alla [spec, TP] per formare la costruzione proclitica; nel caso in cui un pronome diretto prenda invece l'altra via di [Agro, AgrOP], 'pro' sale prima fino alla [spec, AgrSP] tramite il movimento 'spec to spec', successivamente il 'pronome diretto' si muove verso la [Agro, AgrSP], e infine 'V' si sposta verso la [Agro, AgrSP] per formare la costruzione enclitica.

• Journal of Digestive Cancer Research
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• v.4 no.2
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• pp.122-126
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• 2016

Leptomeningeal carcinomatosis occurs in approximately 5% of patients with cancer. The most common cancers involving the leptomeninges are breast, lung cancer and melanoma. However, gastric adenocarcinoma has been rarely reported with leptomeningeal carcinomatosis. The presenting manifestations are usually headache, visual disturbances and seizures. We report a case of leptomeningeal metastasis that presented as a gastric cancer. A 75-year old man was transferred to our hospital for further evaluation and treatment after being diagnosed with adenocarcinoma through endoscopic biopsy during a regular health examination. An abdominal computed tomography (CT) showed AGC, stage IA (cT1N0M0), while an endoscopic examination showed AGC, Borrmann type 2. The patient is currently under observation after undergoing radical subtotal gastrectomy with gastroduodenostomy and subsequent administration of oral chemotherapeutic agents. As an abdominal CT response assessment performed after surgery revealed new metastasis to the liver, the patient received palliative chemotherapy as recurrence was suspected. After receiving chemotherapy in the order of DP (Cisplatin + Docetaxel), FOLFIRI (5-FU + Leucovorin + Irinotecan), an abdominal CT response assessment showed complete response. Since decreased mentality maintained throughout the follow up period based on outpatient clinic, brain MRI was performed and revealed multiple leptomeningeal metastasis. The Patient died 2 days after the diagnosis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.4
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• pp.1042-1058
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• 2024

Terahertz (THz) communication is becoming a key technology for future 6G wireless networks because of its ultra-wide band. However, the implementation of THz communication systems confronts formidable challenges, notably beam splitting effects and high computational complexity associated with them. Our primary objective is to design a hybrid precoder that minimizes the Euclidean distance from the fully digital precoder. The analog precoding part adopts the delay-phase alternating minimization (DP-AltMin) algorithm, which divides the analog precoder into phase shifters and time delayers. This effectively addresses the beam splitting effects within THz communication by incorporating time delays. The traditional digital precoding solution, however, needs matrix inversion in THz massive multiple-input multiple-output (MIMO) communication systems, resulting in significant computational complexity and complicating the design of the analog precoder. To address this issue, we exploit the characteristics of THz massive MIMO communication systems and construct the digital precoder as a product of scale factors and semi-unitary matrices. We utilize Schatten norm and Hölder's inequality to create semi-unitary matrices after initializing the scale factors depending on the power allocation. Finally, the analog precoder and digital precoder are alternately optimized to obtain the ultimate hybrid precoding scheme. Extensive numerical simulations have demonstrated that our proposed algorithm outperforms existing methods in mitigating the beam splitting issue, improving system performance, and exhibiting lower complexity. Furthermore, our approach exhibits a more favorable alignment with practical application requirements, underlying its practicality and efficiency.

• Water for future
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• v.18 no.2
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• pp.163-174
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• 1985

This study aims at the development of a technique for the optimal water allocation by applying Dynamic Programming Model for the effective usage and rational allocation of water resources, in case of which limited water resources in river basin should be used in several stages. In analytical procedure the possible allocable area was firstly zoned into the four areas: Pohang area ($C_1$), Yeungcheon area ($C_2$), Gyeungsan area ($C_3$), Daegu area ($C_4$), which are located between the Yeongcheon dam and the confluence of the lower Kumho river and the main course of the Nakdong river. Secondly, a return function was determined on the basis of the correlation between the GRP in each area and the amount of water used to it. A DP Model, finally, was applied to the allocation of the water resources according to both their usage and the areas. As a result, the fact has been found that when allocating by the area, $C_1$ could be possibly supplied only with the water resources avaiable from the Yeungchon dam, and the maximum units supplied to $C_1$ should be 240 units ($1unit=10^3㎥$ per day), beyond which we ought to develop an alternative water resources. Also, the return from the allocation by the usage exceeded the one from it by the area. At the same time it was more profitable to limit the water supply to $C_1$ into 217 units. In the allocation by the area 240 units and 80 units, if only the water resources available from the Yeungcheon dam used, and 360 units and 80 units if the Doil dam used additionally, could be supplied to $C_1$ and the lower region respectively. In the allocation by the usage 103 units for industrial water with 33 units for both domestic and commercial water and 183 units, if only the water resources available from the Yeungcheon dam used, and 103 units with 33 units and 304 units, if the Doil dam taken into consideration additionally, could be supplied to $C_1$ and the lower region respectively. Therefore, much more water could be allocated to the region of lower Kumho river if the method of water allocation by the usage.

• Journal of the Korean earth science society
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• v.21 no.6
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• pp.663-674
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• 2000

A total of 165 independently oriented core samples were collected from 19 Cretaceous Yuchon Group sites in Kosong area, the southernmost part of the Miryang subbasin of the Kyongsang Basin in southern Korea. Stepwise AF and thermal cleaning revealed antipodal ChRM from 95 samples from 14 sites. Mean ChRM direction is d=26.0$^{\circ}$, i=49.4$^{\circ}$ (${\alpha}_{95}$=8.2$^{\circ}$, k=24.5, n= 14) before bedding correction and d=28.1$^{\circ}$, i=54.2$^{\circ}$ (${\alpha}_{95}$=4.8$^{\circ}$, k=70.6, n= 14) after bedding correction. A 2.88-fold increase of the precession parameter k by bedding correction indicates pre-folding age of the ChRM with 99% confidence level. Palaeomagnetic pole position calculated from the mean ChRM is 67.0$^{\circ}$N, 210.6$^{\circ}$E (dp=4.7$^{\circ}$, dm=6.7$^{\circ}$), which is significantly different neither from the poles of other part of the Kyongsang Basin nor those of Eurasia including SCB and NCB. This suggests stable relative position of the study area with regard to other parts of the Kyongsang Basin as well as to Eurasia continent since Cretaceous. Three ploarity reversals in the Kosong Formation in addition to the coexistence of normal and reversed polarities in the overlying Andesites and Welded Tuff suggest, in reference to the worldwide geomagnetic polarity time scale, an Albian to Maastrichtian (polarity chron 32r-31r) age of the Yuchon Group of the study area. An alleged hypothesis of stratigraphical correspondence between the Kosong Formation in the study area and the Tadaepo Formation in Pusan area is, however, not tenable: Not only because the latter shows a short reverse polarity only in its lowest part of the sequence but also because the Andesites overlying it is wholly normally magnetized, in contrast to the frequent reverals in the case of both the Kosong Formation and Andesites above it.