• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.369-376
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• 2020

The purpose of this study was to evaluate the antioxidant components and activities of HR02/04(8:2)-W, a mixture of S. quelpaertensis Nakai and F. erecta var. sieboldii. We investigated the p-coumaric acid, total flavonoid, and total phenol contents. To evaluate the antioxidant efficacy, we measured the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, FRAP activity, reducing power, and ORAC value. We observed the protective effect of hydrogen peroxide against cell damage in human dermal fibroblasts. As a result of the experiment, the p-coumaric acid, total flavonoid, and total phenol contents were 75.62±1.56 mg/100 g, 21.57±0.84 mg rutin equivalent (RE)/g, and 21.25±1.31 mg gallic acid equivalent (GAE)/g, respectively. In the experiments on antioxidant activity, HR02/04(8:2)-W was found to have significantly increased antioxidant activity. In the human dermal fibroblasts, the HR02/04(8:2)-W treated groups could effectively protect cells against oxidative damage. In this study, we confirmed that HR02/04(8:2)-W is a material with effective physiological antioxidant activity.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.595-600
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• 2019

This study investigated the suitability of freeze-dried ice plant (Mesembryanthemum crystallinum) as the source of an edible healthy salt alternative by examining the content of NaCl, D-pinitol, total phenols, total flavonoids, and DPPH radical scavenging activity compared with those of natural and purified salts. Our results showed that the NaCl content of freeze-dried ice plant, natural and purified salts was 19, 94 and 99%, respectively. The D-pinitol content of freeze-dried ice plant was 777 mg/100 g, whereas D-pinitol was not detected in either natural or purified salts. The total phenol and flavonoid contents of freeze-dried ice plant were 115 mg GAE/100 g and 985 mg RE/100 g, respectively. The DPPH radical scavenging activity of freeze-dried ice plant was markedly higher than that of natural and purified salts. Altogether, these results show that freeze-dried ice plant contains both NaCl and bioactive compounds and can be used as a source of edible salt with positive health effects.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.3
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• pp.113-120
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• 2018

In this study, we proposed a monitoring system for identifying and handling faulty sensing stream data on manufacturing equipments where low-cost sensors can be safely used. Low cost sensors will lessen the cost of implementing distributed monitoring system, but suffer from sensor noises and inaccurate sensed data. Therefore, a distributed monitoring system with low cost sensors should identify faulty signal data as either of sensor fault or machine fault, and filter out faulty signals from sensing fault. To this end, we adopted a fourier transform based diagnostic approach mixed with a weighed moving averaging method, in order to identify faulty signals. We measured how effective our approach is and found out our approach can filter out one-third faulty signals from our experimental environment. In addition, we attached wireless communication modules to reduce sensor and network installation cost. To handle massive sensor data efficiently, we employed unstructured data format with NoSQL based database.

• Analytical Science and Technology
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• v.31 no.3
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• pp.122-133
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• 2018

In this study, groundwater quality data measured for 11 years from 2006 to 2016 were analyzed statistically for 101 civil defense emergency water supply facilities (CDEWSF) in the Gwangju area. The contamination level was quantified into four grades by using excess drinking water quality standards, average concentration analysis, and tendency analysis results for each facility. On the basis of this approach, the groundwater contamination degree of each item was evaluated according to land use status, installation year, depth, and geological distribution. The contamination grade ratios, which were obtained by analyzing three contamination indicators (water quality exceeded frequency, average concentration analysis, and trend analysis) for 15 items on statistically significant of civil defense emergency water was relatively high, in the order of Turbidity (51.5 %) > Color (32.7 %) > Nitrate nitrogen (28.7 %) > Hardness (25.7 %). As a result of the contamination grade analysis, except for the items of Turbidity, Color, and Nitrate nitrogen, the contamination levels were distributed in various degrees from "clean (0)" to "seriously contaminated (3)." Regarding the contamination grade of 12 items, 25 % of the total were classified as "possibly contaminated (1)," and 75 % were rated "clean (0)." The four items (Turbidity, Color, Nitrate nitrogen, and Hardness) for which contamination indication rate were evaluated as "high" by the were visualized on a contamination map.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.151-166
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• 2020

A recommender system is a system that recommends products or services that best meet the preferences of each customer using statistical or machine learning techniques. Collaborative filtering (CF) is the most commonly used algorithm for implementing recommender systems. However, in most cases, it only uses purchase history or customer ratings, even though customers provide numerous other data that are available. E-commerce customers frequently use a search function to find the products in which they are interested among the vast array of products offered. Such search keyword data may be a very useful information source for modeling customer preferences. However, it is rarely used as a source of information for recommendation systems. In this paper, we propose a novel hybrid CF model based on the Doc2Vec algorithm using search keywords and purchase history data of online shopping mall customers. To validate the applicability of the proposed model, we empirically tested its performance using real-world online shopping mall data from Korea. As the number of recommended products increases, the recommendation performance of the proposed CF (or, hybrid CF based on the customer's search keywords) is improved. On the other hand, the performance of a conventional CF gradually decreased as the number of recommended products increased. As a result, we found that using search keyword data effectively represents customer preferences and might contribute to an improvement in conventional CF recommender systems.

• The Korean Journal of Food And Nutrition
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• v.32 no.5
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• pp.462-472
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• 2019

The purpose of this study was to demonstrate the quality characteristics of Brassica juncea cultivated in Jeongseon (BJJ), South Korea. We analyzed the nutritional components and antioxidant activity of BJJ. As a result of the free sugar analysis, the contents of glucose and fructose in BJJ were $0.29{\pm}0.02g/100g$ and $0.10{\pm}0.00g/100g$, respectively. The major fatty acids were palmitic acid, octadecenoic acid and stearic acid. The palmitic acid was the highest at 31.22% of all fatty acids. The major minerals were identified as Ca, P, K, Mg and Na. The contents of vitamin $B_1$, vitamin $B_2$, vitamin $B_6$, vitamin C and vitamin E in BJJ were $0.02{\pm}0.00mg/100g$, $0.087{\pm}0.01mg/100g$, $0.02{\pm}0.00mg/100g$, $0.56{\pm}0.06mg/100g$ and $0.20{\pm}0.03mg\;{\alpha}-TE/100g$, respectively. As a result of the free amino acid analysis, total amino acid contents in BJJ were $2,801.21{\pm}115.38mg/100g$. L-proline content was the highest ($744.30{\pm}119.06mg/100g$) in BJJ. BJJ extract inhibits reactive oxygen species production in 3T3-L1 adipocytes. Also, BJJ extract exhibits a protective effect on oxidative stress in $H_2O_2$-induced human dermal fibroblast. These results indicate that BJJ comprises various valuable nutrients which can be used as functional food ingredients.

• Journal of Korean Society of Archives and Records Management
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• v.21 no.3
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• pp.61-78
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• 2021

Records on Japanese "Comfort Women" have been individually managed by private sectors or institutions, and some are provided as digital archives on the Internet. However, records of digital archives differ in the composition and representation of metadata by individual institutions. Meanwhile, there is a lack of a consistent structure to describe the relationships between and among these records, leading to their fragmentation and disconnectedness. This paper proposes a knowledge model for interlinking the digital archival resources and builds a knowledge graph by integrating the records from distributed digital archives. It derives common elements by analyzing metadata from the diverse digital archives and expresses them in standard vocabularies to semantically describe multiple entities and relationships of the digital archival resources. In particular, the study includes the refinement of collected data to search and thread dispersed records and the enrichment of external data to provide significant contextual information of records. An evaluation of the knowledge graph is performed via a query measuring the (dis)connectivity between the distributed records. As a result, the knowledge graph is capable of interlinking and retrieving fragmented records, providing substantial contextual information on the records with external data enrichment, and searching accurately to match the user's intentions through semantic-based queries.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.255-263
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• 2021

In this study, we assessed the technological characteristics and safety of 88 Enterococcus faecium strains isolated from meju; the strains possess the glutamate decarboxylase gene gadA/B involved in γ-aminobutyric acid production. The study was conducted to evaluate the possibility of introducing E. faecium meju isolates as food fermentation starters. We observed that a NaCl concentration of 6% (w/v) facilitated the growth and acid production of all strains. At a NaCl concentration of 7%, 21 strains (24%) exhibited a low growth rate, 72 strains (82%) a weak acid production, and 16 strains (18%) showed no acid production. All strains exhibited protease activity at a NaCl concentration of 4%. At a NaCl concentration of 5%, 86 strains exhibited weak activity, and one strain showed no protease activity. We could not detect any lipase activity in the investigated strains. None of the strains exhibited an acquired antibiotic resistance to the seven antibiotics tested in the present study, namely ampicillin, chloramphenicol, ciprofloxacin, gentamicin, penicillin G, tetracycline, and vancomycin. We could identify the Enterococcus endocarditis antigen gene efaA and the tyrosine decarboxylase gene tdc contributing to tyramine production, in 88 meju isolates. We could not detect the Enterococcus surface protein gene esp, which is specifically possessed by human-originated E. faecium strains, in any of the 88 strains tested in the study.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.352-363
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• 2021

This study aimed to examine the different factors affecting the intention to purchase meal kits between at-home concept meal kits and eating-out concept meal kits. An online survey was conducted with 565 Korean participants including meal kit experienced (n=412) and non-experienced (n=153). Meal kits selection attributes were organized into five factors, health, price, environmental protection, convenience, and familiarity. To verify the hypothesis, SPSS Statistics 23 was used. The main results can be summarized as follows. First, in the case of the at-home menu, convenience(p < .01), environmental protection(p < .05), and familiarity(p < .01) show positive influences on willingness to buy. Second, for the eating-out menu, health(p < .001) and convenience(p < .001) have positive effects on willingness to buy, but familiarity(p<.01) has a negative effect. This is the first study to categorize the menu of meal kits and investigate each factor affecting willingness to buy. Therefore, the results can offer useful guidelines to meal kit marketers letting them know the consumers' purchase behaviors.

• Journal of Korean Society of Water and Wastewater
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• v.36 no.2
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• pp.81-95
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• 2022

The present study was performed to investigate the effects of NH₃-N and nitrifying microorganisms on the increased BOD of downstream of the Yeongsan river in Gwangju. Water samples were collected periodically from the 13 sampling sites of rivers from April to October 2021 to monitor water qualities. In addition, the trends of nitrogenous biochemical oxygen demand (NBOD) and microbial clusters were analyzed by adding different NH₃-N concentrations to the water samples. The monitoring results showed that NH₃-N concentration in the Yeongsan river was 22 times increased after the inflow of discharged water from the Gwangju 1st public sewage treatment plant (G-1-PSTP). Increased NH₃-N elevated NBOD levels through the nitrification process in the river, consequently, it would attribute to the increase of BOD in the Yeongsan river. Meanwhile, there was no proportional relation between NBOD and NH₃-N concentrations. However, there was a significant difference in NBOD occurrence by sampling sites. Specifically, when 5 mg/L NH₃-N was added, NBOD of the river sample showed 2-4 times higher values after the inflow of discharged water from G-1-PSTP. Therefore, it could be thought other factors such as microorganisms influence the elevated NBOD levels. Through next-generation sequencing analysis, nitrifying microorganisms such as Nitrosomonas, Nitroga, and Nitrospira (Genus) were detected in rivers samples, especially, the proportion of them was the highest in river samples after the inflow of discharged water from G-1-PSTP. These results indicated the effects of nitrifying microorganisms and NH₃-N concentrations as important limiting factors on the increased NBOD levels in the rivers. Taken together, comprehensive strategies are needed not only to reduce the NH₃-N concentration of discharged water but also to control discharged nitrifying microorganisms to effectively reduce the NBOD levels in the downstream of the Yeongsan river where discharged water from G-1-PSTP flows.