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Ahn H, Oh K, Choi SE, Son DH, Nam I, Lim K, Lee O. A Dual-Mode CMOS Power Amplifier with an External Power Amplifier Driver Using 40 nm CMOS for Narrowband Internet-of-Things Applications. Nanomaterials (Basel) 2024; 14:262. [PMID: 38334533 PMCID: PMC10857100 DOI: 10.3390/nano14030262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024]
Abstract
The narrowband Internet-of-Things (NB-IoT) has been developed to provide low-power, wide-area IoT applications. The efficiency of a power amplifier (PA) in a transmitter is crucial for a longer battery lifetime, satisfying the requirements for output power and linearity. In addition, the design of an internal complementary metal-oxide semiconductor (CMOS) PA is typically required when considering commercial applications to include the operation of an optional external PA. This paper presents a dual-mode CMOS PA with an external PA driver for NB-IoT applications. The proposed PA supports an external PA mode without degrading the performances of output power, linearity, and stability. In the operation of an external PA mode, the PA provides a sufficient gain to drive an external PA. A parallel-combined transistor method is adopted for a dual-mode operation and a third-order intermodulation distortion (IMD3) cancellation. The proposed CMOS PA with an external PA driver was implemented using 40 nm-CMOS technology. The PA achieves a gain of 20.4 dB, a saturated output power of 28.8 dBm, and a power-added efficiency (PAE) of 57.8% in high-power (HP) mode at 920 MHz. With an NB-IoT signal (200 kHz π/4-differential quadrature phase shift keying (DQPSK)), the proposed PA achieves 24.2 dBm output power (Pout) with a 31.0% PAE, while satisfying -45 dBc adjacent channel leakage ratio (ACLR). More than 80% of the current consumption at 12 dBm Pout could be saved compared to that in HP mode when the proposed PA operates in low-power (LP) mode. The implemented dual-mode CMOS PA provides high linear output power with high efficiency, while supporting an external PA mode. The proposed PA is a good candidate for NB-IoT applications.
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Affiliation(s)
| | - Kyutaek Oh
- Department of Electrical Engineering, Pusan National University, Busan 46241, Republic of Korea; (K.O.); (I.N.)
| | - Se-Eun Choi
- Samsung Electronics, Hwaseong 18448, Gyeonggi-do, Republic of Korea
| | - Dong-Hee Son
- Hanwha Aerospace, Daejeon 34101, Republic of Korea;
| | - Ilku Nam
- Department of Electrical Engineering, Pusan National University, Busan 46241, Republic of Korea; (K.O.); (I.N.)
| | - Kyoohyun Lim
- Point2 Technology, Seoul 06034, Republic of Korea;
| | - Ockgoo Lee
- Department of Electrical Engineering, Pusan National University, Busan 46241, Republic of Korea; (K.O.); (I.N.)
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Son DH, Ahn HJ, Chung JH, Bae BI, Choi CS. Deflection Estimation Based on the Thermal Characteristics of Composite Deck Slabs Containing Macro-Synthetic Fibers. Materials (Basel) 2021; 14:ma14144052. [PMID: 34300970 PMCID: PMC8307278 DOI: 10.3390/ma14144052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to evaluate the structural performance of composite deck slabs containing macro-synthetic fibers. after a fire by proposing a deflection estimation method for non-fireproof structural decks. Therefore, this study evaluated the fire resistance performance and deflection of deck slabs mixed with macro-synthetic fibers. Afterward, the deflection estimation method considering the thermal characteristics of concrete and deck plates was proposed. A material test was first conducted to evaluate the mechanical properties of concrete mixed with macro-synthetic fibers. This test found that the compressive strength and elasticity modulus of concrete mixed with macro-synthetic fibers was greater than that of general concrete. A flexural tensile test confirmed that residual strength was maintained after the maximum strength was achieved. The fire resistance of the deck slab was adequate even when a fire-resistant coating was not applied. The internal temperature was lowest for the specimen with macro-synthetic fibers. Deflection was evaluated using previously published equations and standards. The deflection evaluation confirmed that the temperature distribution should be applied differently in the estimation method that uses the thermal load of the deck slab.
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Affiliation(s)
- Dong-Hee Son
- Department of Architectural Engineering, Hanyang University, Seoul 04763, Korea; (D.-H.S.); (H.-J.A.)
| | - Hyo-Jun Ahn
- Department of Architectural Engineering, Hanyang University, Seoul 04763, Korea; (D.-H.S.); (H.-J.A.)
| | - Joo-Hong Chung
- Department of Smart Architecture Civil Engineering, Daejin University, Pocheon, Gyeonggi-Do 11159, Korea;
| | - Baek-Il Bae
- Department of Digital Architectural and Urban Engineering, Hanyang Cyber University, Seoul 04763, Korea;
| | - Chang-Sik Choi
- Department of Architectural Engineering, Hanyang University, Seoul 04763, Korea; (D.-H.S.); (H.-J.A.)
- Correspondence:
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Nam JP, Park JK, Son DH, Kim TH, Park SJ, Park SC, Choi C, Jang MK, Nah JW. Evaluation of polyethylene glycol-conjugated novel polymeric anti-tumor drug for cancer therapy. Colloids Surf B Biointerfaces 2014; 120:168-75. [PMID: 24918700 DOI: 10.1016/j.colsurfb.2014.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 04/03/2014] [Accepted: 04/19/2014] [Indexed: 12/18/2022]
Abstract
A novel polymeric prodrug (PXPEG) was prepared to enhance the solubility of an anti-cancer drug, paclitaxel, in aqueous solutions and decrease the cytotoxicity by PEGylation, which means PEG attached to another molecule. In addition, the targeting ligand, transferrin (TF), was modified to PXPEG to enhance the therapeutic efficacy. The targeting ligand-modified PXPEG (TFPXPEG) was examined by (1)H-NMR to confirm the successful synthesis. The synthesized TFPXPEG had better solubility than the free drug against aqueous solution. The particle size of TFPXPEG was approximately 197.2nm and it had a spherical shape. The MTT assay showed that the anti-tumor efficiency of TFPXPEG was better than that of TF-unmodified PXPEG. In the KB tumor-bearing mouse model, the tumor volume of TFPXPEG treated groups was decreased dramatically by more than 2 fold or 3 fold compared to the PBS or PXPEG treated groups. The in vitro and in vivo evaluation showed that TFPXPEG had better efficacy than that of PXPEG due to the targeting effect of targeting ligands, such as TF.
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Affiliation(s)
- Joung-Pyo Nam
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Jun-Kyu Park
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Dong-Hee Son
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Tae-Hun Kim
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Sun-Jeong Park
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Seong-Cheol Park
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Changyong Choi
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Mi-Kyeong Jang
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea
| | - Jae-Woon Nah
- Department of Polymer Science and Engineering, Sunchon National University, 255 Juang-ro, Suncheon 540-950, Jeollanam-do, Republic of Korea.
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Choi YG, Kim HS, Park YH, Jeong SH, Son DH, Oh YK, Yeom IT. Improvement of the thickening and dewatering characteristics of activated sludge by electroflotation (EF). Water Sci Technol 2005; 52:219-26. [PMID: 16459795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30 minutes of EF operation, 57-84% of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. In addition, the EF thickened sludge showed much better dewaterability both in SRF and cake solid content. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed dewaterbility improvement.
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Affiliation(s)
- Y G Choi
- Department of Civil and Environmental Engineering, Sungkyunkwan University, Suwon, Korea.
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Kweon CH, Kwon BJ, Woo SR, Kim JM, Woo GH, Son DH, Hur W, Lee YS. Immunoprophylactic effect of chicken egg yolk immunoglobulin (Ig Y) against porcine epidemic diarrhea virus (PEDV) in piglets. J Vet Med Sci 2000; 62:961-4. [PMID: 11039591 DOI: 10.1292/jvms.62.961] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is the causative agent of neonatal diarrhea in piglets, which causes high mortality rates. In this study, the immunoprophylactic effects of chicken egg yolk immunoglobulin (Ig Y) against PEDV were investigated in neonatal pigs. Ig Y was found to reduce the mortality in piglets after challenge exposures. The field application of Ig Y also revealed significant differences in survival rates of piglets given Ig Y, as compared with placebo or control. The results in this study indicated that Ig Y against PEDV could be an alternative way of supplementing prophylactic measures like colostral antibodies from sows.
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Affiliation(s)
- C H Kweon
- National Veterinary Research and Quarantine Service, Ministry of Agriculture and Forestry, Anyang, Korea
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