글루탐산 생산을 위한 Lactococcus lactis HY7803 균주의 대두 발효 적용

Lee Jungmin,Heo Sojeong,Choi Jihoon,Pyo Eunji,Lee Myounghee,Shin Sangick,Lee Jaehwan,Lee Junglyoul,정도원 한국미생물·생명공학회 2023 한국미생물·생명공학회지 Vol.51 No.1

The glutamic acid producing strain for development savory taste enhancing foods was identified the possibility through application into soybean fermentation. To check the effects on glutamic acid production during soybean fermentation, Lactococcus lactis HY7803 was introduced as a starter. The soybean samples were analyzed on days 0, 7, 14 and 21. The numbers of bacteria decreased gradually, while the content of amino-type nitrogen increased during fermentation in the soybean with L. lactis HY7803. Glutamic acid content in soybeans with L. lactis HY7803 increased from 114.99 ± 9.37 pmol/ul on day 0 to 138.14 ± 1.76 pmol/ul on day 21, showing an overall higher amino acid content than soybeans without L. lactis HY7803 and similar content to soybeans with Aspergillus oryzae SNU-G. It was clearly distinguished through principal component analysis. Consequently, our results indicate that L. lactis HY7803 is available as a fungus replacement and may be a good starter strain for enhancing savory taste in vitro as well as soybean fermentation.

A parameterized model to select discriminating features on keystroke dynamics authentication on smartphones

Lee, Hyungu,Hwang, Jung Yeon,Lee, Shincheol,Kim, Dong In,Lee, Sung-Hoon,Lee, Jaehwan,Shin, Ji Sun Elsevier 2019 Pervasive and mobile computing Vol.54 No.-

<P><B>Abstract</B></P> <P>Nowadays, smartphones work not only as personal devices, but also as distributed IoT edge devices uploading information to a cloud. Their secure authentications become more crucial as information from them can spread wider. Keystroke dynamics is one of prominent candidates for authentications factors. Combined with PIN/pattern authentications, keystroke dynamics provide a user-friendly multi-factor authentication for smartphones and other IoT devices equipped with keypads and touch screens. There have been many studies and researches on keystroke dynamics authentication with various features and machine-learning classification methods. However, most of researches extract the same features for the entire user and the features used to learn and authenticate the user’s keystroke dynamics pattern. Since the same feature is used for all users, it may include features that express the users’ keystroke dynamics well and those that do not. The authentication performance may be deteriorated because only the discriminative feature capable of expressing the keystroke dynamics pattern of the user is not selected. In this paper, we propose a parameterized model that can select the most discriminating features for each user. The proposed technique can select feature types that better represent the user’s keystroke dynamics pattern using only the normal user’s collected samples. In addition, performance evaluation in previous studies focuses on average EER(equal error rate) for all users. EER is the value at the midpoint between the FAR(false acceptance rate) and FRR(false rejection rate), FAR is the measure of security, and FRR is the measure of usability. The lower the FAR, the higher the authentication strength of keystroke dynamics. Therefore, the performance evaluation is based on the FAR. Experimental results show that the FRR of the proposed scheme is improved by at least 10.791% from the maximum of 31.221% compared with the other schemes.</P>

WELCOME MESSAGE

Jaehwan Lee 한국디지털디자인협의회 2007 (사)한국디지털디자인협의회 conference Vol.2007 No.8

Model System Study for the Mutagenicity of Sugar-Glycine Systems

JaeHwan Lee,Han-Seung Shin 한국식품과학회 2008 Food Science and Biotechnology Vol.17 No.4

The mutagenicity after heating of different sugars (glucose, fructose, galactose, and tagatose) on the non-enzymatic browning reaction in different sugars and glycine model system was investigated. The model system containing 0.2 M glycine and 0.2M of different sugars in 10mL water was heated at 150±5℃ for 30min. After heating, degree of non-browning reaction intensity and mutagenicity using Salmonella typhimurium TA 98 were examined. Heated glycine model systems containing different sugars increased their mutgenicity ranged from 30 to 372 revertant colonies. After heating for 40 min, mutagenicity was achieved with glycine model systems containing 4 different sugars with by 145, 356, 206, and 369 revertants per plate, respectively. The glycine model systems containing fructose or tagatose were significantly (p<0.05) higher mutagenic activity than glycine model systems containing glucose or galactose after 40min of heating. The linear regression between Maillard reaction intensity and mutagenic activities (slope=32.38, R²=0.93) indicates that mutagenicity could be fully ascribed to Maillard reaction products.

In-Storage Anti-Virus System via On-Demand Inspection

LEE, Jaehwan,KIM, Youngrang,SHIN, Ji Sun 'Institute of Electronics, Information and Communi 2018 IEICE transactions on information and systems Vol.101e.d No.8

Outboard Diesel Engine

Jaehwan Lee(이재환) 한국디자인학회 2019 한국디자인학회 국제초대전도록 Vol.2019 No.11

Efficient Heterogeneous Network-Routing Method Based on Dynamic Control Middleware for Cyber-Physical System

Lee, Hyungsoo,Lee, Jaehwan,Nam, Sanghyuck,Park, Sangoh Hindawi Limited 2018 Journal of sensors Vol.2018 No.-

<P>A cyber-physical system depends on stable control and interaction between the many systems and devices connected to the network. Dynamic control middleware, which considers the characteristics of a cyber-physical system, supports the dynamic search and control of devices existing on the global network using Internet protocol version 6 (IPv6). However, systems and devices may connect to a network using a variety of heterogeneous protocols, not just IPv6. To solve the problem of heterogeneous protocols, this paper proposes a routing technique which enables network devices to communicate using different protocols. The proposed network-routing module can register devices with various protocols and improve the stability of the efficient heterogeneous network.</P>

An Empirical Performance Analysis on Hadoop via Optimizing the Network Heartbeat Period

( Jaehwan Lee ),( June Choi ),( Hongchan Roh ),( Ji Sun Shin ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11

To support a large-scale Hadoop cluster, Hadoop heartbeat messages are designed to deliver the significant messages, including task scheduling and completion messages, via piggybacking to reduce the number of messages received by the NameNode. Although Hadoop is designed and optimized for high-throughput computing via batch processing, the real-time processing of large amounts of data in Hadoop is increasingly important. This paper evaluates Hadoop’s performance and costs when the heartbeat period is controlled to support latency sensitive applications. Through an empirical study based on Hadoop 2.0 (YARN) [1] architecture, we improve Hadoop’s I/O performance as well as application performance by up to 13 percent compared to the default configuration. We offer a guideline that predicts the performance, costs and limitations of the total system by controlling the heartbeat period using simple equations. We show that Hive performance can be improved by tuning Hadoop’s heartbeat periods through extensive experiments.

Oxidative stability of extracts from red ginseng and puffed red ginseng in bulk oil or oil-in-water emulsion matrix

Lee, Sang-Jun,Oh, Sumi,Kim, Mi-Ja,Sim, Gun-Sub,Moon, Tae Wha,Lee, JaeHwan The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.3

Background: Explosive puffing can induce changes in the chemical, nutritional, and sensory quality of red ginseng. The antioxidant properties of ethanolic extracts of red ginseng and puffed red ginseng were determined in bulk oil and oil-in-water (O/W) emulsions. Methods: Bulk oils were heated at $60^{\circ}C$ and $100^{\circ}C$ and O/W emulsions were treated under riboflavin photosensitization. In vitro antioxidant assays, including 2,2-diphenyl-1-picrylhudrazyl, 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid, ferric reducing antioxidant power, total phenolic content, and total flavonoid content, were also performed. Results: The total ginsenoside contents of ethanolic extract from red ginseng and puffed red ginseng were 42.33 mg/g and 49.22 mg/g, respectively. All results from above in vitro antioxidant assays revealed that extracts of puffed red ginseng had significantly higher antioxidant capacities than those of red ginseng (p < 0.05). Generally, extracts of puffed red and red ginseng had high antioxidant properties in riboflavin photosensitized O/W emulsions. However, in bulk oil systems, extracts of puffed red and red ginseng inhibited or accelerated rates of lipid oxidation, depending on treatment temperature and the type of assay used. Conclusion: Although ethanolic extracts of puffed red ginseng showed stronger antioxidant capacities than those of red ginseng when in vitro assays were used, more pro-oxidant properties were observed in bulk oils and O/W emulsions.

The behavior of frost layer growth under conditions favorable for desublimation

Lee, Jaehwan,Lee, Kwan-Soo Elsevier 2018 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.120 No.-

<P><B>Abstract</B></P> <P>The purpose of this study is to understand the behavior of frost layer growth under conditions favorable for desublimation. The frosting experiments were conducted on a horizontal cooling surface. Condensation did not occur at the initial stage of frosting, and feather-shaped frost crystals were formed on the cooling surface. These frost crystals grew one-dimensionally while maintaining their shapes. In addition, the effects of operating conditions (air temperature, air velocity, air absolute humidity, cooling surface temperature) on frost layer growth under the conditions favorable for desublimation were investigated. As the cooling surface temperature decreased, the increase in the amount of frost was insignificant. Additionally, an increase in air velocity increased the frost density but not the thickness of the frost layer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> No condensation occurs and feather-shaped frost crystals are formed directly on the surface. </LI> <LI> Crystal growth processes in the initial stage of the frosting were observed. </LI> <LI> The effect of cooling surface temperature on the frost mass was insignificant. </LI> <LI> Increase of air velocity only increased the density of frost layer, not the frost thickness. </LI> </UL> </P>