• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3641-3655
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• 2016

Wireless sensor networks (WSNs) provide a promising approach to monitor the physical environments, to prolong the network lifetime by exploiting the mutual correlation among sensor readings has become a research focus. In this paper, we design a hierarchical network framework which guarantees layered-compression. Meanwhile, a data sorting-based adaptive spatial compression scheme (DS-ASCS) is proposed to explore the spatial correlation among signals. The proposed scheme reduces the amount of data transmissions and alleviates the network congestion. It also obtains high compression performance by sorting original sensor readings and selectively discarding the small coefficients in transformed matrix. Moreover, the compression ratio of this scheme varies according to the correlation among signals and the value of adaptive threshold, so the proposed scheme is adaptive to various deploying environments. Finally, the simulation results show that the energy of sorted data is more concentrated than the unsorted data, and the proposed scheme achieves higher reconstruction precision and compression ratio as compared with other spatial compression schemes.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3307-3311
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• 2013

A new fiber optical sensor was developed for the determination of 2,4-dichlorophenol (DCP). The sensor was based on DCP oxidation by oxygen with the catalysis of iron(III) tetrasulfophthalocyanine (Fe(III)PcTs). The optical oxygen sensing film with $Ru(bpy)_3Cl_2$ as the fluorescence indicator was used to determine the consumption of oxygen in solution. A lock-in amplifier was used for detecting the lifetime of the oxygen sensing film by measuring the phase delay change of the sensor head. The different variables affecting the sensor performance were evaluated and optimized. Under the optimal conditions (i.e. pH 6.0, $25^{\circ}C$, Fe(III)PcTs concentration of 0.62 mg/mL), the linear detection range and response time of the sensor are $1.0{\times}10^{-6}-9.0{\times}10^{-6}$ mol/L and 250 s, respectively. The sensor displays high selectivity, good repeatability and stability, and can be used as an effective tool in analyzing DCP concentration in practical samples.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.415-423
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• 2014

The purpose of this study is preparing for the expansion of water leisure sports in accordance with the marina port building project, enforcement of Reservoir Development Special Act and the revision of Water Leisure Sports Safety Act by government. For the purpose, this study investigated the status of physical education class as a cultural study in universities, collected/analyzed the related literatures to analyze the role of physical education class and analyzed the curriculum of university physical education as a cultural study being taught at 17 national and public universities in nationwide 12 areas. The university physical education as a cultural study should be given as a preparation for future water leisure sports age so that it can achieve its inherent purpose of fostering sports demonstrating ability as a lifetime sports. By doing such, people will have better life while enjoying water leisure sports.

• The Journal of Korean Association of Computer Education
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• v.23 no.3
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• pp.65-70
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• 2020

In wireless sensor networks, data packets are send to the sink node. So traffic increases near the sink node. This causes delay and collision. To solve this problem, the proposed mechanism used half rotation antenna. By using a half rotation antenna, the delay of data packets can be reduced. Also we propose a method to efficiently use the energy of the node using BRN(backup receiver node) and increase the lifetime of the entire networks. Our numerical analysis and simulation results show that our mechanism outperforms RI-MAC protocol in terms of energy consumption and transmission delay.

• The Journal of Korean Society for School & Community Health Education
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• v.16 no.2
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• pp.45-57
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• 2015

Objectives: This study identified a multicultural families and households youth targeting adolescents drinking behavior and sexual status, and alcohol problems and gender analyzes and the relevance of the cup and behavior. Methods: This study analysed drinking problem and sexual behavior among adolescents of multi-cultural and general families which is based on the primitive data from the Ninth Youth Risk Behavior Web-based Survey, 2013. All analysis were conducted using SPSS version 18. Results: Multicultural family adolescents showed significantly higher in lifetime's drinking experience, beginning age of drinking, binge drinking, CRAFFT and sex experience than general family adolescents. Conclusions: Therefore the result of this study suggests that families, schools and society should perceive and solve the problem concerning the drinking behavior and sex experience of the multicultural familiy adolescents.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.475-479
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• 2009

In ad hoc network, the scarce energy management of the mobile devices has become a critical issue in order to extend the network lifetime. Current research activity for the Minimum Energy Multicast (MEM) problem has been focused on devising efficient centralized greedy algorithms for static ad hoc networks. In this paper, we consider mobile ad hoc networks(MANETs) that could provide the reliable monitoring and control of a variety of environments for remote place. Mobility of MANET would require the topology change frequently compared with a static network. To improve the routing protocol in MANET, energy efficient routing protocol would be required as well as considering the mobility would be needed. In this paper, we propose a new method, the CACH(Context-aware Clustering Hierarchy) algorithm, a hybrid and clustering-based protocol that could analyze the link cost from a source node to a destination node. The proposed analysis could help in defining the optimum depth of hierarchy architecture CACH utilize. The proposed CACH could use localized condition to enable adaptation and robustness for dynamic network topology protocol and this provide that our hierarchy to be resilient. As a result, our simulation results would show that CACH could find energy efficient depth of hierarchy of a cluster.

• Safety and Health at Work
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• v.2 no.3
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• pp.250-259
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• 2011

Objectives: Intimate partner violence (IPV) is a significant global public health concern, affecting 5.3 million US individuals annually. An estimated 1 in 3 women globally are abused by an intimate partner in their lifetime, and the effects carry over into the workplace. This article examines employers' perceptions of IPV in the workplace, targeting supervisors of Latina employees. Methods: Fourteen employers and supervisors of small service-sector companies in Oregon were interviewed using semi-structured interviews. Interpretive description was used to identify themes. These qualitative interviews preceded and helped to formulate a larger workplace intervention study. Results: The following themes were found and are detailed: (1) factors associated with recognizing IPV in the workplace, (2) effects of IPV on the work environment and (3) supervisors' responses to IPV-active vs. passive involvement. Also, supervisors' suggestions for addressing IPV in the workplace are summarized. Conclusion: These findings demonstrate the need for more IPV-related resources in the workplace to be available to supervisors as well as survivors and their coworkers. The needs of supervisors and workplaces vary by site, demonstrating the need for tailored interventions, and culturally appropriate workplace interventions are needed for Latinas and other racially and ethnically diverse populations.

• Journal for History of Mathematics
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• v.25 no.1
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• pp.15-27
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• 2012

Thomas Harriot(1560-1621) introduced a simplified notation for algebra. His fundamental research on the theory of equations was far ahead of that time. He invented certain symbols which are used today. Harriot treated all answers to solve equations equally whether positive or negative, real or imaginary. He did outstanding work on the solution of equations, recognizing negative roots and complex roots in a way that makes his solutions look like a present day solution. Since he published no mathematical work in his lifetime, his achievements were not recognized in mathematical history and mathematics education. In this paper, by comparing his works with Viete and Descartes those are mathematicians in the same age, I show his achievements in mathematics.

• 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.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1573-1578
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• 2007

Fluorescence quenching of norfloxacin (NOR) by Cu2+, Ni2+, Co2+ and Mn2+ was studied in water. The change in the fluorescence intensity and lifetime was measured as a function of quencher concentration at various temperatures. According to the Stern-Volmer plots, the NOR was quenched both by collisions and complex formation with the same quencher. However, the static quenching had a more important effect on the emission. Large static and dynamic quenching constants support significant ion-dipole and orbital-orbital interactions between NOR and cations. The both quenching constants by Cu2+ were the largest among quenchers. Also, quenching mechanism of Cu2+ was somewhat different. The change in the absorption spectra due to the quencher provided information on static quenching. The fluorescence of NOR was relatively insensitive to both the dynamic and static quenching compared with other quinolone antibiotics. This property can be explained by the twisted intramolecular charge transfer.