• Environmental Engineering Research
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• 제20권4호
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• pp.347-355
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• 2015

The growth kinetics of phototrophic microorganisms can be controlled by the light irradiance, the concentration of an inorganic nutrient, or both. A multi-component kinetic model is proposed and tested in novel batch experiments that allow the kinetic parameters for each factor to be estimated independently. For the cyanobacterium Synechocystis sp. PCC6803, the estimated parameters are maximum specific growth rate $({\mu}_{max})=2.8/d$, half-maximum-rate light irradiance $(K_L)=11W/m^2$, half-inhibition-rate light irradiance $(K_{L,I})=39W/m^2$, and half-maximum-rate concentration for inorganic carbon $(K_{S,Ci})=0.5mgC/L$, half-maximum-rate concentration for inorganic nitrogen $(K_{S,Ni})=1.4mgN/L$, and half-maximum-rate concentration for inorganic phosphorus $(K_{S,Pi})=0.06mgP/L$. Compared to other phototrophs having ${\mu}max$ estimates, PCC6803 is a fast-growing r-strategist relying on reaction rate. Its half-maximum-rate and half-inhibition rate values identify the ranges of light irradiance and nutrient concentrations that PCC6803 needs to achieve a high specific growth rate to be a sustainable bioenergy source. To gain the advantages of its high maximum specific growth rate, PCC6803 needs to have moderate light illumination ($7-62W/m^2$ for ${\mu}_{syn}{\geq}1/d$) and relatively high nutrient concentrations: $N_i{\geq}2.3 mgN/L$, $P_i{\geq}0.1mgP/L$, and $C_i{\geq}1.0mgC/L$.

• 한국미생물·생명공학회지
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• 제35권1호
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• pp.45-51
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• 2007

Arthrospira에 대한 종속영양배양 결과, A. platensis M9108(A. platensis PCC 9108의 고농도 glucose 내성 돌연변이)은 glucose 5.0 g/L 첨가된 SOT 배지에서 8일 동안 배양하여 0.54 g/L의 생물량을 얻었으며, 일일생산량은 0.068 g/L/day을 보였고, specific growth $rate(\mu)$는 0.014/h를 보였다. A. platensis M9108의 일일생산량과 $\mu$는 모균주인 A. platensis PCC 9108에 비하여 각각 1.3배와 1.2배 향상된 결과를 보였으며, 이전에 보고된 결과에 비하여 각각 1.3배와 1.8배 증가하였다. Arthrospira의 건체량 중 지방산과 r-linolenic acid의 함량은 각각 $1.94\sim4.97%$와 $0.13\sim1.33%$로 균주에 따라 상당히 다양하였다. Arthrospira는 유기탄소원으로 glucose를 첨가한 조건에서 성장이 가장 좋았으며, A. platensis M9108의 경우 maltose의 이용능도 glucose 이용 능과 비슷하였다. A. platensis M9108의 성장은 glucose의 5.0 g/L까지는 증가하였지만, 10.0 g/L에서는 저해되는 양상을 보였다. 또한 고농도의 탄소원을 이용한 종속영양배양 중 발생하는 세포의 뭉침 현상이 A. platensis M9108에서는 관찰되지 않아 안정적으로 고농도 생산에 유용할 것으로 판단된다.

• Structural Engineering and Mechanics
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• 제60권6호
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• pp.979-999
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• 2016

Stainless steel wire mesh (SSWM) is an alternative material for strengthening of structural elements similar to fiber reinforced polymer (FRP). Finite element (FE) method based Numerical investigation for evaluation of axial strength of SSWM strengthened plain cement concrete (PCC) and reinforced cement concrete (RCC) columns is presented in this paper. PCC columns of 200 mm diameter with height 400 mm, 800 mm and 1200 mm and RCC columns of diameter 200 mm with height of 1200 mm with different number of SSWM wraps are considered for study. The effect of concrete grade, height of column and number of wraps on axial strength is studied using finite element based software ABAQUS. The results of numerical simulation are compared with experimental study and design guidelines specified by ACI 440.2R-08 and CNR-DT 200/2004. As per numerical analysis, an increase in axial capacity of 15.69% to 153.95% and 52.39% to 109.06% is observed for PCC and RCC columns respectively with different number of SSWM wraps.

• 말소리와 음성과학
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• 제12권1호
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• pp.85-95
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• 2020

아동이 산출하는 말소리를 평가할 때 단어와 문장을 유도하여 산출한 말소리를 분석하고, 자발화를 이용하여 분석하기도 한다. 단어 검사와 자발화 검사의 한계를 보완할 수 있는 평가 방법으로 문장 따라말하기 과제가 있다. 문장 따라말하기 과제를 통한 아동의 말소리 평가는 자발화와 유사한 특성을 보이면서 단어와 같이 제한된 시간 안에 다양한 음소를 평가할 수 있다. 본 연구에서는 다양한 모음문맥에서 자음을 배치하고 모든 음소가 3회 이상의 출현 기회를 가질 수 있도록 계획된 11개의 문장 따라말하기를 통해 연령과 성별에 따라서 단어단위 음운지표와 개정자음정확도의 발달을 살펴보았다. 전국에 거주하는 3세부터 7세까지 아동 535명을 대상으로 UTAP2에 새롭게 포함된 11개 문장 따라말하기 과제를 실시하였다. 말소리발달을 평가할 수 있는 지표 PCC-R, PWC, PMLU, PWP을 구하였다. 아동은 연령별 6개월 단위로 10개의 집단을 구분하고 각 지표에 대해 연령집단과 성별에 따른 차이를 분석하였다. 연구 결과, 모든 지표에서 연령이 증가함에 따라 수치가 상승하였으며 연령집단 간 차이는 유의하였다. 성별에 따른 차이와 연령과 성별의 상호작용효과는 유의하지 않은 것으로 나타났다. 본 연구는 전국에서 자료를 수집하였고, 연령집단을 6개월로 나누어 보았으며, 집단별 데이터를 충분히 수집하였다는 점과 단어와 자발화 검사의 한계점을 보완할 수 있는 문장 따라말하기라는 새로운 말소리 평가 방법의 연령별 준거 자료를 제시하였다는 측면에서 의의가 있다.

• ALGAE
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• 제27권2호
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• pp.75-82
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• 2012

$Arthrospira$ $platensis$ and $Arthrospira$ $maxima$ are species of cyanobacteria used in health foods, animal feed, food additives, and fine chemicals. This study conducted a comparison of the 16S rRNA gene and $cpcBA$-intergenic spacer ($cpcBA$-IGS) sequences in $Arthrospira$ strains from culture collections around the world. A cluster analysis divided the 10 $Arthrospira$ strains into two main genotypic clusters, designated I and II, where Group I contained $A.$ $platensis$ SAG 86.79, UTEX 2340, $A.$ $maxima$ KCTC AG30054, and SAG 49.88, while Group II contained $A.$ $platensis$ PCC 9108, NIES 39, NIES 46, and SAG 257.80. However, although $A.$ $platensis$ PCC 9223 belonged to Group II-2 based on its $cpcBA$-IGS sequence, this strain also belonged to Group I based on its 16S rRNA gene sequence. Phylogenetic analyses based on the 16S rRNA gene and $cpcBA$-IGS sequences showed no division between $A.$ $platensis$ and $A.$ $maxima$, plus the 16S rRNA gene and $cpcBA$-IGS sequence clusters did not indicate any well-defined geographical distribution, instead overlapping in a rather interesting way. Therefore, the current study supports some previous conclusions based on 16S rRNA gene and $cpcBA$-IGS sequences, which found that $Arthrospira$ taxa are monophyletic. However, when compared with 16S rRNA sequences, $cpcBA$-IGS sequences may be better suited to resolve close relationships and intraspecies variability.

• The Plant Pathology Journal
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• 제27권3호
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• pp.242-248
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• 2011

Several soil bacteria were found to degrade N-Acylhomoserine lactones (NAHLs), thereby interfering with the bacterial quorum sensing system. In this research, fifteen strains of NAHL degrading rhizobacteria were isolated from potato rhizosphere. Based on phenotypic characteristics and 16S rDNA sequence analyses, the strains were identified as members of genera Bacillus, Streptomyces, Arthrobacter, Pseudomonas and Mesorhizobium. All tested isolates were capable to degrade both synthetic and natural NAHL produced by Pectobacterium carotovorum subsp. carotovorum (Pcc) strain EMPCC. In quorum quenching experiments selected isolates, especially Mesorhizobium sp., were markedly reduced the pathogenicity of Pcc strain EMPCC in potato tubers and totally suppressed tissue maceration on potato tubers. These led to consider the latter as a useful biocontrol agent against Pectobacterium spp.

• 한국재료학회지
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• 제33권4호
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• pp.164-174
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• 2023

The bandgap characteristics of semiconductor materials are an important factor when utilizing semiconductor materials for various applications. In this study, based on data provided by AFLOW (Automatic-FLOW for Materials Discovery), the bandgap of a semiconductor material was predicted using only the material's compositional features. The compositional features were generated using the python module of 'Pymatgen' and 'Matminer'. Pearson's correlation coefficients (PCC) between the compositional features were calculated and those with a correlation coefficient value larger than 0.95 were removed in order to avoid overfitting. The bandgap prediction performance was compared using the metrics of R² score and root-mean-squared error. By predicting the bandgap with randomforest and xgboost as representatives of the ensemble algorithm, it was found that xgboost gave better results after cross-validation and hyper-parameter tuning. To investigate the effect of compositional feature selection on the bandgap prediction of the machine learning model, the prediction performance was studied according to the number of features based on feature importance methods. It was found that there were no significant changes in prediction performance beyond the appropriate feature. Furthermore, artificial neural networks were employed to compare the prediction performance by adjusting the number of features guided by the PCC values, resulting in the best R² score of 0.811. By comparing and analyzing the bandgap distribution and prediction performance according to the material group containing specific elements (F, N, Yb, Eu, Zn, B, Si, Ge, Fe Al), various information for material design was obtained.

• 한국세라믹학회지
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• 제53권1호
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• pp.1-6
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• 2016

In this year, Koreans have a shortage in agricultural and drinking water due to severe algal blooms generated in major lakes. Waste oyster shells were obtained from temporary storage near the workplace at which oysters were separated from their shells. Heating ($1000^{\circ}C$ for 1 h in air) was employed to convert raw oyster shell powders into calcium oxide powders that reacted efficiently with phosphorus and nitrogen to remove algal blooms from eutrophicated wastewater. As the dispersed amount of heated oyster shell powders was increased, water clarity and visual light penetration were improved. Coagulation, precipitation and carbonation process of the heated oyster shell powders in a water purifier facilitated removal of eutrophication nutrient such as phosphorus and nitrogen, which is both beneficial and economically viable. $CO_2$ implantation by carbonation treatment not only produced thermodynamically stable CaO in oyster shells to derive precipitated calcium carbonate (PCC) but also accelerated algal removal by activation of coagulation and precipitation process. The use of oyster shell powders led to a mean reduction of 97% in total phosphate (T-P), a mean reduction of 91% in total nitrogen (T-N) and a maximum reduction of 51% in chemical oxygen demand (COD), compared with the total pollutant load of raw algal solution. Remarkable water quality improvement of algal removal by heated oyster shell powders and PCC carbonation treatment will allow utilization as water resources to agricultural or industrial use.

• 대한후두음성언어의학회지
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• 제21권1호
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• pp.42-47
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• 2010

Backgrounds and Objects: Carcinoma of the tongue is the most common cancer of the oral cavity. A primary treatment strategy includes surgery and/or radiotherapy. Resection of the tongue often results in speech dysfunction, which depends on the site and extent of resection, type of reconstruction, and the mobility of remaining tongue. This study aimed to evaluate the characteristics of articulation errors that were resulted from the partial glossectomy without free flap reconstruction. Materials & Method : Articulation evaluations including speech intelligibility and percent of correct consonants (PCC) were performed for 24 patients who underwent partial glossectomy for their T1 or T2 tongue cancer. Mobility of the tongue, size of the resected tongue, and the history of adjuvant radiotherapy were analyzed for their relationship with the results of articulation evaluation. Results: Speech intelligibility score was $6.4{\pm}0.9$ (on 7-point scale) and overall PCC was 96.9%. There were close relationships between the size of resection and limitations in the tongue mobility, especially in "protrusion and elevation (r=-0.687)" and "retroflexion (r=-0.775)". Errors in "alveolar fricatives" and "palatal affricates" were also closely related with the size of resection (r=-0.537 and -0.538, respectively). PCC for "liquid sound" /r/ was 83.2%, which was closely related with the history of radiation therapy. Conclusion : Overall articulatory function was satisfactory in cases of early tongue cancer after partial glossectomy of a limited volume without flap reconstruction. However, the size of resection and the history of radiation therapy were closely related to the limitations in some types of tongue mobility and the resultant articulation errors.

• Clinical Psychopharmacology and Neuroscience
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• 제16권4호
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• pp.449-460
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• 2018

Objective: Prior functional magnetic resonance imaging (fMRI) work has revealed that children/adolescents with disruptive behavior disorders (DBDs) show dysfunctional reward/non-reward processing of non-social reinforcements in the context of instrumental learning tasks. Neural responsiveness to social reinforcements during instrumental learning, despite the importance of this for socialization, has not yet been previously investigated. Methods: Twenty-nine healthy children/adolescents and 19 children/adolescents with DBDs performed the fMRI social/non-social reinforcement learning task. Participants responded to random fractal image stimuli and received social and non-social rewards/non-rewards according to their accuracy. Results: Children/adolescents with DBDs showed significantly reduced responses within the caudate and posterior cingulate cortex (PCC) to non-social (financial) rewards and social non-rewards (the distress of others). Connectivity analyses revealed that children/adolescents with DBDs have decreased positive functional connectivity between the ventral striatum (VST) and the ventromedial prefrontal cortex (vmPFC) seeds and the lateral frontal cortex in response to reward relative to non-reward, irrespective of its sociality. In addition, they showed decreased positive connectivity between the vmPFC seed and the amygdala in response to non-reward relative to reward. Conclusion: These data indicate compromised reinforcement processing of both non-social rewards and social non-rewards in children/adolescents with DBDs within core regions for instrumental learning and reinforcement-based decision-making (caudate and PCC). In addition, children/adolescents with DBDs show dysfunctional interactions between the VST, vmPFC, and lateral frontal cortex in response to rewarded instrumental actions potentially reflecting disruptions in attention to rewarded stimuli.