• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1805-1824
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• 2013

Recently, the use of wireless body area networks (WBAN) has been increasing rapidly in medical healthcare applications. WBANs consist of smart nodes that can be used to sense and transmit vital data such as heart rate, temperature and ECG from a human body to a medical centre. WBANs depend on limited resources such as energy and bandwidth. In order to utilise these resources efficiently, a very well organized medium access control (MAC) protocol must be considered. In this paper, a new, adaptive and energy-efficient MAC protocol, entitled isMAC, is proposed for WBANs. The proposed MAC is based on multi-channel communication and aims to prolong the network lifetime by effectively employing (i) a collision prevention mechanism, (ii) a coordinator node (WCN) selection algorithm and (iii) a transmission power adjustment approach. The isMAC protocol has been developed and modelled, by using OPNET Modeler simulation software. It is based on a networking scenario that requires especially high data rates such as ECG, for performance evaluation purposes. Packet delay, network throughput and energy consumption have been chosen as performance metrics. The comparison between the simulation results of isMAC and classical IEEE 802.15.4 (ZigBee) protocol shows that isMAC significantly outperforms IEEE 802.15.4 in terms of packet delay, throughput and energy consumption.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.27-42
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• 2018

This study analyzed the utility of ammonium chloride ($NH_4Cl$) as a nitrogen source for methanotroph communities. When cultured in nitrate mineral salt (NMS) medium, the methanotroph community we identified four families, seven genera, and 16 type I and type II species of methanotrophs. Among species in the Methylobacter genus, Methylobacter marinus could be actively cultured in NMS medium without NaCl addition. Following the addition of 25 mM $NH_4Cl$, the numbers of the type I genera Methylomonas, Methylococcus, and Methylobacter were increased, whereas the numbers of the type II genera Methylocystis and Methylosinus were decreased after 5 days. In methanotroph communities, certain concentrations of $NH_4Cl$ affected methane consumption and growth of methanotrophs at the community level. $NH_4Cl$ caused a considerable decrease in the methane consumption rate and the expression of soluble methane monooxygenases (sMMOs) but did not inhibit the growth of Methylomonas methanica expressing sMMO. These results could be attributed to competitive antagonism of MMOs due to their direct involvement in ammonia oxidation.

• The Korean Journal of Physiology
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• v.17 no.1
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• pp.55-61
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• 1983

Effects of SITS (4-acetamido-4'-isothiocyano-2, 2'-disulfonic stilbene) on a $Na^+$ transport, tissue oxygen consumption and Na-K-ATPase activity were studied in isolated frog skin preparations. $Na^+$ transport was estimated by measuring the short-circuit current(SC) across the skin; oxygen consumption was measured in separated epidermis as well as in intact skin; and Na-K-ATPase was assayed in $24,000{\times}g$ fraction of epidermal homogenates. The SCC across the skin Was rapidly and substantially reduced in the presence of 10 mM SITS in the medium bathing the outside(mucosal) surface of the skin. When the drug was added to the inside(serosal) bathing medium, there was about 20 min delay for inhibition of SCC and the effect was less pronounced. The above effect of SITS was independent of the presence of $Cl^-$ in the bathing medium. The oxygen consumption of the skin tissue was not affected by SITS, but the Na-K-ATPase activity of a subcellular fraction of the skin was significantly inhibited. These results suggest that SITS retards $Na^+$ transport across the frog skin primarily by interfering $Na^+$ entry across the mucosal membrance of the epithelial cell, although an effect on $Na^+$ pump can not be ruled out completely.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.304-311
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• 1999

Batch kinetics during the exo-polysaccharide (EPS) fermentation of Ganoderma lucidum was investigated as a function of different substrates (glucose and starch), substrate concentration $(1{\sim}7%,\;w/v)$ and subculture (3 times). Logistic model for mycelial growth fitted the experimental data better than Monod and two thirds power model. The Luedeking-Pirt equation was adequate to fit the kinetic data of product formation and substrate consumption. The EPS production was strongly non-growth associated, although it was mixed type. The product formation and sustrate consumption by growth associated mechanism decreased as the concentration of glucose increased, while those of the non-growth associated mechanism increased. However, starch medium increased the growth associated and non-growth associated substrate consumption indicating higher availability of substrate. Also, batch culture in starch medium showed the higher specific growth rate and stability during subculture than those in glucose medium. In conclusion, the enhanced EPS production and stability in the subculture was found to be remarkably improved by use of starch as sole carbon source in medium. The maximum mycelium dry weight and EPS production of 9.463 and 10.410 g/l, respectively, were obtained after shake culture of 7 days at $30^{\circ}C$ from the media containing 7% starch.

• Nutrition Research and Practice
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• v.10 no.2
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• pp.198-205
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• 2016

BACKGROUND/OBJECTIVES: A healthy diet has been reported to be associated with physical development, cognition and academic performance, and personality during adolescence. This study was performed to investigate the relationships among milk consumption and academic performance, learning motivation and strategies, and personality among Korean adolescents. SUBJECTS/METHODS: The study was divided into two parts. The first part was a survey on the relationship between milk consumption and academic performance, in which intakes of milk and milk products and academic scores were examined in percentiles among 630 middle and high school students residing in small and medium-sized cities in 2009. The second part was a survey on the relationships between milk consumption and learning motivation and strategy as well as personality, in which milk consumption habits were collected and Learning Motivation and Strategy Test (L-MOST) for adolescents and Total Personality Inventory for Adolescents (TPI-A) were conducted in 262 high school students in 2011. RESULTS: In the 2009 survey, milk and milk product intakes of subjects were divided into a low intake group (LM: ${\leq}60.2g/day$), medium intake group (MM: 60.3-150.9 g/day), and high intake group (HM: ${\geq}151.0g/day$). Academic performance of each group was expressed as a percentile, and performance in Korean, social science, and mathematics was significantly higher in the HM group (P < 0.05). In the 2011 survey, the group with a higher frequency of everyday milk consumption showed significantly higher "learning strategy total," "testing technique," and "resources management technique" scores (P < 0.05) in all subjects. However, when subjects were divided by gender, milk intake frequency, learning strategy total, class participation technique, and testing technique showed significantly positive correlations (P < 0.05) in boys, whereas no correlation was observed in girls. Correlations between milk intake frequency and each item of the personality test were only detected in boys, and milk intake frequency showed positive correlations with "total agreeability", "organization", "responsibility", "conscientiousness", and "intellectual curiosity" (P < 0.05). CONCLUSION: Intakes of milk and milk products were correlated with academic performance (Korean, social science, and mathematics) in Korean adolescents. In male high school students, particularly, higher milk intake frequency was positively correlated with learning motivation and strategy as well as some items of the personality inventory.

• Asia pacific journal of information systems
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• v.25 no.2
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• pp.370-402
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• 2015

The dynamic capabilities of social media are changing the nature of contemporary news by allowing users to communicate and create content, deliver and share newsworthy information, and consume news. News organizations engage with social media because this computer-mediated tool provides an alternative platform for delivering news and connecting with global audiences. This role of social media is conceptualized as its complementarity. However, when mass user-generated-content is constantly shared with other users, more users are attracted to indulge in news-seeking activities on social media. This phenomenon potentially fulfills users' news requirements on social media, which is contrary to what news companies envisioned when they began engaging with social media. This dichotomous role of social media, providing complementarity and showing the potential for becoming a superior news medium, is conceptualized as its competing-complementarity. This paper offers preliminary evidence of competing-complementarity by analyzing the news consumption of individuals. Such consumption is explained through the theoretical perspective of punctuated equilibrium by conceptualizing news consumption as a deep structure radically impacted by a disruptive technology. Although social media benefit news organizations, its competing potential poses serious challenges to their monopolistic controls on news production, distribution, readership, and revenue generation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.927-930
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• 2012

The sensor network technology for core technology of ubiquitous computing is in the spotlight recently, the research on ubiquitous sensor network is proceeding actively which is composed many different sensor node. One of the important condition for design of sensor node is to extend for network life which is to minimize power-consumption under the limited resources of sensor network. This study suggest routing protocol that was used second level cluster structure to reduce power-consumption of sensor node. the first level use the previous routing protocol under the LEACH, second level decide to transmit or not by comparision of data value for Effective Usage, reduce the unnecessary power-consumption.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.163-170
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• 2002

This report describes the use of a transtubular bioreactor to study the relative effects of diffusion versus perfusion of medium on antibody production by a hybridoma cell line. The study was performed with a high-density cell culture maintained in a serum-free, low-protein medium for 77 days. It was determined that the reactor possessed a macro-mixing pattern residence time distribution similar to a continuous stirred tank reactor (CSTR), However, due to the arrangement of the medium lines in the reactor, the flow patterns for nutrient distribution consist of largely independent medium path lengths ranging from short to long. When operated with cyclic, reversing, transtubular medium flow, some regions of the reactor (with short residence times) are more accessible to medium than others (with long residence times). From this standpoint, the reactor can be divided into three regions: a captive volume, which consists of medium primarily delivered via diffusion; a lapped volume, which provides nutrients through unilateral convection; and a swept volume, which operates through bilateral convection. The relative sizes of these three volumes were modified experimentally by changing the period over which the direction of medium flow was reversed from 15 min (larger captive volume) to 9 h (larger swept volume). The results suggest that antibody concentration increases as the size of the diffusion-limited (captive) volume is increased to a maximum at around 30 min with a sharp decrease thereafter. As reflected by changes in measured consumption of glucose and production of lactate, no significant difference in cellular metabolism occurred as the reactor was moved between these different states. These results indicate that the mode of operation of the transtubular bioreactor may influence antibody productivity under serum-free, low-protein conditions with minimal effects on cellular metabolism.

• Smart Media Journal
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• v.12 no.11
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• pp.18-26
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• 2023

The building energy management system (BEMS), a system designed to efficiently manage energy production and consumption, aims to address the variable nature of power consumption within buildings due to their physical characteristics, necessitating stable power supply. In this context, accurate prediction of building energy consumption becomes crucial for ensuring reliable power delivery. Recent research has explored various approaches, including time series analysis, statistical analysis, and artificial intelligence, to predict power consumption. This paper analyzes the strengths and weaknesses of the Prophet model, choosing to utilize its advantages such as growth, seasonality, and holiday patterns, while also addressing its limitations related to data complexity and external variables like climatic data. To overcome these challenges, the paper proposes an algorithm that combines the Prophet model's strengths with the gated recurrent unit (GRU) to forecast short-term (2 days) and medium-term (7 days, 15 days, 30 days) building energy consumption. Experimental results demonstrate the superior performance of the proposed approach compared to conventional GRU and Prophet models.

• Fire Science and Engineering
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• v.24 no.3
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• pp.58-65
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• 2010

The fire accidents having recently occurred are getting more and more larger and causing lots of damage in terms of property loss and casualties increase, so there is in need of technical fire safety development like comprehensive prevention solution in order to effectively prevent. Especially, the needing of new paradigm for advanced fire safe technology is gathering strength in high-rise modern building construction. Therefore, we want to find out on this paper what is a correlation between heat release rate measurement and smoke release volume by three parts of oxygen consumption calorimeter in bench scale calorimeter (cone calorimeter/ISO 5660/Avg.500Kw), Medium scale calorimeter (Room corner tester, Single burning Item/ISO 9750, EN 13823/Avg.3MW), and large scale calorimeter (Industry calorimeter/Avg. 10MW). Thus, Smoke detective of new paradigm devised by making use of a correlation between heat release and smoke production is to help reduce loss property and casualties. Ultimately, based on this theory, a new concept of fire alarm and evacuation system will be developed and expected to apply to a skyscraper.