An Ultra-Low-Power 16-Bit Second-Order Incremental ADC With SAR-Based Integrator for IoT Sensor Applications

Shim, Junbo,Kim, Min-Kyu,Hong, Seong-Kwan,Kwon, Oh-Kyong IEEE 2018 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.65 No.12

<P>This brief presents a 16-bit amplifier-free second-order incremental analog-to-digital converter (IADC2) for sensor applications. The proposed IADC2 employs a power efficient successive approximation register (SAR)-based integrator for the charge transfer operation, which consumes dynamic power only, instead of using power-consuming operational transconductance amplifiers that consume a high static current. The proposed amplifier thus achieves ultra-low-power consumption in low-frequency operation. In addition, the charge redistribution period of a capacitor digital-to-analog converter (CDAC) in the SAR-based integrator is split in a time-interleaving way, such that the CDAC can be shared by the first and second integrators. A test chip, including the proposed IADC2, was fabricated using 0.18- <TEX>${\mu }\text{m}$</TEX> standard CMOS process technology. The measurement results show that the proposed IADC2 achieves a differential nonlinearity of −0.51/+0.74 LSB and an integral nonlinearity of −3.12/+0.24$ LSB. In addition, the measured maximum signal-to-noise ratio, and an effective number of bits are 93.4 dB and 15.22-bit for the dc signal, respectively. The measured power consumption is 0.24 <TEX>${\mu }\text{W}$</TEX> at a sampling frequency of 10 kHz. Therefore, the proposed IADC2 is suitable for various sensor applications requiring ultra-low-power consumption.</P>

Comparative proteomics of the mixotrophic dinoflagellate Prorocentrum micans growing in different trophic modes

Junbo Shim,Tatyana A. Klochkova,한종원,김광훈,유영두,정해진 한국조류학회I 2011 ALGAE Vol.26 No.1

Protein profiles of a common mixotrophic dinoflagellate, Prorocentrum micans, growing autotrophically and mixotrophically (fed on the cryptophyte Rhodomonas salina) were compared using two-dimensional gel electrophoresis (2-DE) to determine if they vary in different trophic modes. Approximately 2.3% of the detected proteins were differentially expressed in the different trophic modes. Twelve proteins observed only in the mixotrophic condition had lower pI value (<5) than the fifteen proteins observed only in the autotrophic condition (>5). When the internal amino acid sequences of five selected proteins differentially expressed between autotrophic and mixotrophic conditions were analyzed using matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry, two proteins that were specifically expressed in the autotrophic condition showed homology to glyceraldehyde-3-phosphatase dehydrogenase (GAPDH) and a bacterial catalase. Three mixotrophy-specific proteins showed homology to certain hypothetical proteins from an insect and bacteria. These results suggested the presence of certain gene groups that are switched on and off according to the trophic mode of P. micans.

Keeping house: evaluation of housekeeping genes for real-time PCR in the red alga, Bostrychia moritziana (Florideophyceae)

Shim, Junbo,Shim, Eunyoung,Kim, Gwang Hoon,Han, Jong Won,Zuccarello, Giuseppe C. The Korean Society of Phycology 2016 ALGAE Vol.31 No.2

Biological response of cells to variable conditions should affect the expression level of certain genes. Quantification of these changes in target genes needs stable internal controls. Real-time quantitative polymerase chain reaction (PCR) has traditionally used reference or ‘housekeeping’ genes, that are considered to maintain equal expression in different conditions, to evaluate changes in target genes between samples and experimental conditions. Recent studies showed that some housekeeping genes may vary considerably in certain biological samples. This has not been evaluated in red algae. In order to identify the optimal internal controls for real-time PCR, we studied the expression of eleven commonly used housekeeping genes; elongation factor 1-alpha, glyceraldehyde-3-phosphate dehydrogenase, β-actin, polyubiquitin, 30S ribosomal gene, 60S ribosomal gene, beta-tubulin, alpha-tubulin, translation initiation factor, ubiquitin-conjugating enzyme, and isocitrate dehydrogenase in different life-history stages of Bostrychia moritziana. Our results suggest that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 30S ribosomal gene, have the most stable gene expression levels between the different life history stages (male, female, carposporophyte, and tetrasporophyte), while the other genes are not satisfactory as internal controls. These results suggest that the combinations of GAPDH and 30S would be useful as internal controls to assess expression level changes in genes that may control different physiological processes in this organism or that may change in different life history stages. These results may also be useful in other red algal systems.

야간 환경 인지 가능 적외적 램프 선행 개발

김형선(Hyeongseon Kim),박성호(Sungho Park),심준보(Junbo Shim),차동은(Dongeun Cha),이대희(Daehee Lee),임정욱(Jungwuk Lim),정동혁(Donghyuk Jeong),김균하(Gyunha Kim) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

Transcriptome analysis of the short-term photosynthetic sea slug Placida dendritica

Ji Hee Han,Tatyana A. Klochkova,한종원,Junbo Shim,Gwang Hoon Kim 한국조류학회I 2015 ALGAE Vol.30 No.4

The intimate physical interaction between food algae and sacoglossan sea slug is a pertinent system to test the theory that “you are what you eat.” Some sacoglossan mollusks ingest and maintain chloroplasts that they acquire from the algae for photosynthesis. The basis of photosynthesis maintenance in these sea slugs was often explained by extensive horizontal gene transfer (HGT) from the food algae to the animal nucleus. Two large-scale expressed sequence tags databases of the green alga Bryopsis plumosa and sea slug Placida dendritica were established using 454 pyrosequencing. Comparison of the transcriptomes showed no possible case of putative HGT, except an actin gene from P. dendritica, designated as PdActin04, which showed 98.9% identity in DNA sequence with the complementary gene from B. plumosa, BpActin03. Highly conserved homologues of this actin gene were found from related green algae, but not in other photosynthetic sea slugs. Phylogenetic analysis showed incongruence between the gene and known organismal phylogenies of the two species. Our data suggest that HGT is not the primary reason underlying the maintenance of short-term kleptoplastidy in Placida dendritica.

A revaluation of algal diseases in Korean Pyropia (Porphyra) sea farms and their economic impact

Kim, Gwang Hoon,Moon, Kyoung-Hyoun,Kim, Je-Yoon,Shim, Junbo,Klochkova, Tatyana A. The Korean Society of Phycology 2014 ALGAE Vol.29 No.4

As with land crops, cultivated algae are affected by various diseases ranging from large outbreaks of a disease to chronic epiphytes, which may downgrade the value of the final product. The recent development of intensive and dense mariculture practices has enabled some new diseases to spread much faster than before. A new disease is reported almost every year, and the impact of diseases is expected to increase with environmental change, such as global warming. We observed the incidence of diseases in two Pyropia sea farms in Korea from 2011 to 2014, and estimated the economic loss caused by each disease. Serious damage is caused by the oomycete pathogens, Pythium porphyrae and Olpidiopsis spp., which decreased the productivity of the Pyropia sea farms. In Seocheon sea farms, an outbreak of Olpidiopsis spp. disease resulted in approximately US $1.6 million in loss, representing approximately 24.5% of total sales during the 2012-2013 season. The damage caused by green-spot disease was almost as serious as oomycete diseases. An outbreak of green-spot disease in the Seocheon sea farms resulted in approximately US $1.1 million in loss, representing 10.7% of total sales in the 2013-2014 season in this area. However, the causative agent of green-spot disease is still not confirmed. "Diatom felt" is regarded as a minor nuisance that does not cause serious damage in Pyropia; however, our case study showed that the economic loss caused by "diatom felt" might be as serious as that of oomycete diseases. Bacteria and cyanobacteria are indigenous members of epiphytic microbial community on Pyropia blades, but can become opportunistic pathogens under suitable environmental conditions, especially when Pyropia suffers from other diseases. A regular acid wash of the Pyropia cultivation nets is the most common treatment for all of the above mentioned diseases, and represents approximately 30% of the total cost in Pyropia sea farming. However, the acid wash is ineffective for some diseases, especially for Olpidiopsis and bacterial diseases.

Transcriptome analysis of the short-term photosynthetic sea slug Placida dendritica

Han, Ji Hee,Klochkova, Tatyana A.,Han, Jong Won,Shim, Junbo,Kim, Gwang Hoon The Korean Society of Phycology 2015 ALGAE Vol.30 No.4

The intimate physical interaction between food algae and sacoglossan sea slug is a pertinent system to test the theory that “you are what you eat.” Some sacoglossan mollusks ingest and maintain chloroplasts that they acquire from the algae for photosynthesis. The basis of photosynthesis maintenance in these sea slugs was often explained by extensive horizontal gene transfer (HGT) from the food algae to the animal nucleus. Two large-scale expressed sequence tags databases of the green alga Bryopsis plumosa and sea slug Placida dendritica were established using 454 pyrosequencing. Comparison of the transcriptomes showed no possible case of putative HGT, except an actin gene from P. dendritica, designated as PdActin04, which showed 98.9% identity in DNA sequence with the complementary gene from B. plumosa, BpActin03. Highly conserved homologues of this actin gene were found from related green algae, but not in other photosynthetic sea slugs. Phylogenetic analysis showed incongruence between the gene and known organismal phylogenies of the two species. Our data suggest that HGT is not the primary reason underlying the maintenance of short-term kleptoplastidy in Placida dendritica.

이중 파장 보정방법 기반 다이나믹 분광타원편광계의 안정도 최적화

최인호,헤리저데헌거흐 사이드,최석현,황국현,심준보,김대석,Choi, Inho,Kheiryzadehkhanghah, Saeid,Choi, Sukhyun,Hwang, Gukhyeon,Shim, Junbo,Kim, Daesuk 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.3

This paper describes a dynamic spectroscopic ellipsometry based on dual-wavelength calibration. DSE provides ellipsometric parameters at rates above 20 Hz, but the interferometer's sensitivity to temperature makes it difficult for that proposed system to maintain stable 𝜟k over long periods of time. To solve this problem, we set up an additional path in the DSE to perform simulations of the polarization phase calibration method using dual wavelengths. Through simulation, we were able to eliminate most of the polarization phase error and maintain a stable 𝜟k in the long-term stability experiment for 10 hours. This is the result that the 𝜟k stability of the proposed system is improved tens of times compared to the existing system.