• 한국항행학회논문지
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• 제15권1호
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• pp.76-82
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• 2011

다수의 이종 무선망들 중에서 스케일러블 비디오 스트리밍 서비스에 적합한 망을 선택하는 경우, 기존에는 망 품질만을 고려하였다. 그러나 사용자 중심의 체감품질을 고려하지 않고 망 선택을 함에 따라 서비스에 대한 체감 만족이 낮아지는 문제가 있다. 이에 따라, 본 논문에서는 스케일러블 비디오 스트리밍 서비스를 위해 망의 품질뿐만 아니라 일반 사용자, 가격민감 사용자, 품질민감 사용자로 사용자의 소비성향을 구분하고 비디오 품질열화에 대한 서비스 가격 만족도 등을 고려한 체감품질기반의 망 선택 알고리즘을 제안한다. 실험결과 일반 사용자보다 가격민감 사용자와 품질민감 사용자는 각각 36%, 9% 정도 체감만족 향상을 갖는 망을 선택할 수 있었다.

• 한국수산과학회지
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• 제53권3호
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• pp.388-394
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• 2020

An emerging interest in healthy eating has led to an increase in the consumption of rice mixed with various types of grains. Cooked rice was prepared with five different seaweeds, Hizikia fusiformis, Sargassum fulvellum, Enteromorpha compressa, Undaria pinnatifida, and Gracilaria verrucosa, and the antioxidant activity was measured. In addition, the antioxidant activities of 80% ethanol and methanol extracts of the five seaweeds were compared. Total phenolic content (TPC), total reducing power (TRP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) cation radical scavenging activities of the ethanol extracts were higher than those of the methanol extracts. The TPC of raw seaweed ethanol extracts was from 7.58 to 26.27 mg gallic acid equivalent (GAE)/g. The antioxidant activities of both extracts of Hizikia fusiformis were the highest among the five seaweeds, and the antioxidant activities of the cooked rice were lower than those of the raw seaweed extracts. The DPPH radical scavenging activities of cooked white rice, mixed grains, barley, and a mixture of white rice and barely added with Hizikia fusiformis, Sargassum fulvellum and Undaria pinnatifida were 3.17, 23.12, 31.11 and 10.66%, respectively. These results demonstrate the addition of seaweeds to cooked rice helps to improve the antioxidant activity compared to white rice alone.

• 한국토양비료학회지
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• 제49권4호
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• pp.318-326
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• 2016

Two phosphate solubilizing bacteria, Pantoea rodasii PSB-11and Enterobacter aerogenes PSB-12, were isolated from button mushroom compost and employed to assess their synergistic effect in liquid medium and on growth of green gram plants by single and co-inoculation of the strains. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($521{\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of Pantoea strain ($485{\mu}g\;ml^{-1}$) and Enterobacter strain ($470{\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production and glucose consumption was observed in the E. aerogenes PSB-12 single inoculated culture medium rather than those of co-inoculation. According to the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 10.6% and 10.7% higher shoot and root growth respectively compared to the control. Therefore, in concluding, co-inoculation of the strains P. rodasii and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, being short assessment period of the present study, we recommend in engaging further works under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• 상하수도학회지
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• 제32권4호
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• pp.357-361
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• 2018

Forward osmosis (FO) process has been attracting attention for its potential applications such as industrial wastewater treatment, wastewater reclamation and seawater desalination. Particularly, in terms of fouling reversibility and operating energy consumption, the FO process is assumed to be preferable to the reverse osmosis (RO) process. Despite these advantages, there is a difficulty in the empirical step due to the lack of separation and recovery techniques of the draw solution. Therefore, rather than using FO alone, recent developments of the FO process have adapted a hybrid system without draw solution separation/recovery systems, such as the FO-RO osmotic dilution system. In this study, we investigated the performance of the hollow fiber FO module according to various operating conditions. The change of permeate flow rate according to the flow rates of the draw and feed solutions in the process operation is a factor that increases the permeate flow rate, one of the performance factors in the positive osmosis process. Our results reveal that flow rates of draw and feed solutions affect the membrane performance, such as the water flux and the reverse solute flux. Moreover, use of hydraulic pressure on the feed side was shown to yield slightly higher flux than the case without applied pressure. Thus, optimizing the operating conditions is important in the hollow fiber FO system.

• Journal of Computing Science and Engineering
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• 제12권1호
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• pp.24-35
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• 2018

Deep convolutional neural network (DCNN) is an advanced technology in image recognition. Because of extreme computing resource requirements, DCNN implementation with software alone cannot achieve real-time requirement. Therefore, the need to implement DCNN accelerator hardware is increasing. In this paper, we present a field programmable gate array (FPGA)-based hardware accelerator design of DCNN targeting handwritten Hangul character recognition application. Also, we present design optimization techniques in SDAccel environments for searching the optimal FPGA design space. The techniques we used include memory access optimization and computing unit parallelism, and data conversion. We achieved about 11.19 ms recognition time per character with Xilinx FPGA accelerator. Our design optimization was performed with Xilinx HLS and SDAccel environment targeting Kintex XCKU115 FPGA from Xilinx. Our design outperforms CPU in terms of energy efficiency (the number of samples per unit energy) by 5.88 times, and GPGPU in terms of energy efficiency by 5 times. We expect the research results will be an alternative to GPGPU solution for real-time applications, especially in data centers or server farms where energy consumption is a critical problem.

• Korean Membrane Journal
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• 제7권1호
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• pp.28-33
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• 2005

The feasibility of producing sulfuric acid and ammonia water from ammonium sulfate was investigated by an integrated process including ammonia stripping (AS) and electrodialysis with bipolar membrane (EDBM). It was suggested that the production of sulfuric acid using ammonia stripping-electrodialysis with bipolar membrane (ASEDBM) was effective in obtaining high concentration of sulfuric acid compared with EDBM alone. AS was carried out over pH 11 and within the range of temperatures, $20^{\circ}C{\~}60^{\circ}C$. Sodium sulfate obtained using AS was used as the feed solution of EDBM. The recovery of ammonia increased from $40\%$ to $80\%$ at $60^{\circ}C$ due to the increased mobility of ammonium ion. A pilot-scale EDBM system, which is composed of two compartments and 10 cell pairs with an effective membrane area of $200 cm^2$ per cell, was used for the recovery of sulfuric acid. The performance was examined in the range of 0.1 M${\~}$1.0 M concentration of concentrate compartment and of $25 mA/cm^2{\~}62.5 mA/cm^2$ of current density. The maximum current efficiency of $64.9\%$ was obtained at 0.1 M sulfuric acid because the diffusion rate at the anion exchange membrane decreased as the sulfuric acid of the concentrate compartment decreased. It was possible to obtain the 2.5 M of sulfuric acid in the $62.5 mA/cm^2$ with a power consumption of 13.0 kWh/ton, while the concentration of sulfuric acid was proportional to the current density below the limiting current density (LCD). Thus, the integrating process of AS-EDBM enables to recover sulfuric acid from the wastewaters containing ammonium sulfate.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.79-84
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• 2004

Zinc intake and status of South Koreans from rural, urban and metropolitan areas were investigated. The dietary habits of 760 healthy male and female adult subjects with a mean age of 54 were assessed using a food frequency questionnaire and were verified using 24 h dietary recall. Daily Zn intakes for men and women were 7.4$\pm$5.4 mg and 7.0$\pm$5.4 mg, respectively, which were 62% and 70% of the Korean RDA. The phytate : zinc and phytate ${\times}$ calcium : zinc molar ratios were 38 and 398, respectively. Both the low intake of zinc and the high extremely phytate and phytate ${\times}$ calcium ratios with Zinc suggest that South Koreans may be at risk of zinc deficiency. Plasma zinc (86$\pm$61 $\mu\textrm{g}$/dL), urinary zinc (33$\pm$27 $\mu\textrm{g}$/dL) and plasma alkaline phosphatase (102$\pm$52 mU/mL) levels within the normal range did not however suggest marked Zinc deficiency in these subjects. However, conventional zinc biomarkers aye known to be unreliable for assessment of marginal zinc deficiency. Based on zinc intake alone, it is likely that at least a proportion of these subjects were marginally zinc deficient and the wider consumption of zinc rich, phytate deficient foods, particularly in rural areas, would be beneficial.

• Archives of Plastic Surgery
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• 제44권1호
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• pp.5-11
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• 2017

Background Conscious sedation has been widely utilized in plastic surgery. However, inadequate research has been published evaluating adequate drug dosage and depth of sedation. In clinical practice, sedation is often inadequate or accompanied by complications when sedatives are administered according to body weight alone. The purpose of this study was to identify variables influencing the depth of sedation during conscious sedation for plastic surgery. Methods This prospective study evaluated 97 patients who underwent plastic surgical procedures under conscious sedation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and glucose levels were measured. Midazolam and ketamine were administered intravenously according to a preset protocol. Bispectral index (BIS) recordings were obtained to evaluate the depth of sedation 4, 10, 15, and 20 minutes after midazolam administration. Associations between variables and the BIS were assessed using multiple regression analysis. Results Alcohol intake and female sex were positively associated with the mean BIS (P<0.01). Age was negatively associated with the mean BIS (P<0.01). Body mass index (P=0.263), creatinine clearance (P=0.832), smoking history (P=0.398), glucose (P=0.718), AST (P=0.729), and ALT (P=0.423) were not associated with the BIS. Conclusions Older patients tended to have a greater depth of sedation, whereas females and patients with greater alcohol intake had a shallower depth of sedation. Thus, precise dose adjustments of sedatives, accounting for not only weight but also age, sex, and alcohol consumption, are required to achieve safe, effective, and predictable conscious sedation.

• 펄프종이기술
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• 제47권5호
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• pp.74-79
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• 2015

Wood powder is widely used in paperboard mills to increase bulk and reduce drying-energy consumption, but this material also deteriorates paper strength because it interferes with the bonds between fibers. Although there have been many studies done to improve the strength of paperboard containing wood powder, specific applications have not recently been observed in paperboard mills. In this study, we carried out a new approach for improving paperboard strength by developing a new organic filler with the ability to increase the bonds between fibers. The residue of tapioca starch was used as raw material to manufacture an organic filler. The functionalities, including bulk and strength, were evaluated by making handsheets containing either wood powder or tapioca organic filler, or a mixture of the two, and measuring their physical properties. The organic filler showed lower bulk improvement and higher paperboard strength than the wood powder. The mixture of tapioca organic filler and wood powder showed improved paperboard strength compared to wood powder alone. Therefore, tapioca residue can be used as a raw material to manufacture an organic filler for paperboard mills.

• 대한지역사회영양학회지
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• 제17권4호
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• pp.390-406
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• 2012

Childhood obesity has rapidly increased worldwide and is one of the most serious health problems in this age group. In order to prevent and manage childhood obesity, we developed a nutrition education website. The website consisted of three parts. The first part was made for self-assessment with regard to obesity index, dietary habits, food frequency, dietary attitude, nutrition knowledge, nutrient intake, energy expenditure, and the stage of behavioral change, and tailored messages and advice according to the assessment results. A total of 612 real-size food photos as well as a nutrient database of 3,346 foods and 541 dishes were created to help children estimate nutrient intakes accurately. In addition, an energy expenditure database of 156 activities for children was established to calculate calorie consumption. The second part was made for setting long-term and short-term goals and keeping track of the changes in energy intake and expenditure in one's own page. The third part was made for education. Various types of nutrition information were provided; texts, pictures, calculators and games. The readability and design of the website were evaluated by 46 obese children. Usefulness, design and readability of the website were found to be desirable for children. This website is expected to be used by an obese child alone or with parents or nutrition teachers in order to control body weight through healthy dietary habits and physical activities. In addition, a non-obese child can also use this website for maintaining healthy dietary habits and preventing obesity.