• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.1-6
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• 2012

In crowded subway stations indoor air quality (IAQ) is a key factor for ensuring the safety and health of passengers. Since physical variables that describing IAQ such as the concentration of particulate, $CO_2$, VOCs and biological agents need to be closely monitored and controlled in multiple locations within subway stations and in remote sites, concept of web-based monitoring and control network using both wireless and wired media needs to be implemented. Connecting remote wireless sensor network and device (LonWorks) networks to the IP network based on the concept of VDN can provide a powerful, integrated, distributed monitoring and control performance. In this study, performance of wireless and wired network in VDN for monitoring and control of IAQ in subway stations is evaluated. Specifically, delay induced in wireless and wired networks, and data transmission rate are evaluated. A key parameter is identified in assuring safety and health of passengers in subway stations.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.31-47
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• 2012

The mobile Virtual Private Network (MVPN) of Internet Engineering Task Force (IETF) is not designed to support NEwork MObility (NEMO) and is not suitable for real-time applications. Therefore, an architecture and protocol which supports VPN in NEMO are needed. In this paper, we proposed the cost-reduced secure mobility management scheme (CR-SeMMS) which is designed for real-time applications in conjunction with VPN and also which is based on the session initiation protocol (SIP). Our scheme is to support MVPN in NEMO, so that the session is well maintained while the entire network is moved. Further, in order to reduce the authentication delay time which considers as a delaying factor in hands-off operations, the signaling time which occurs to maintain the session is shortened through proposing the hands-off scheme adopting an authentication method based on HMAC based One Time Password (HOTP). Finally, our simulation results show the improvement of the average hands-off performance time between our proposed scheme and the existing schemes.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.97-103
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• 2006

In this paper, a control method of a mini ozone generator is proposed, and also a cooling technique is described which is cooling down the flowing air gap into a silent discharger to $2^{\circ}C$ to generate ozone of high density and diffusing power. As the digital control system for this method, a double feedback loop is designed which detects the voltage and current of equivalent capacitor of the discharger and compensates for the poor power waveform caused by the noise at high discharging frequency. During the plant modeling of this system, computing time factor is considered as a unique parameter of the power system to improve the transient responses with regard to fluctuating load and to replenish the computing time delay of the controller. Through the experiment, sinusoidal input current for discharger can be acquired and all the effectiveness of this accurate control system over unstable ozone discharger are proved.

• Environmental Engineering Research
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• v.21 no.4
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• pp.333-340
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• 2016

An Artificial Neural Network including a Radial Basis Function (RBF) and a Time Delay Neural Network (TDNN) was used to predict total dissolved solid (TDS) in the river Zayanderud. Water quality parameters in the river for ten years, 2001-2010, were prepared from data monitored by the Isfahan Regional Water Authority. A factor analysis was applied to select the inputs of water quality parameters, which obtained total hardness, bicarbonate, chloride and calcium. Input data to the neural networks were pH, $Na^+$, $Mg^{2+}$, Carbonate ($CO{_3}^{-2}$), $HCO{_3}^{-1}$, $Cl^-$, $Ca^{2+}$ and Total hardness. For learning process 5-fold cross validation were applied. In the best situation, the TDNN contained 2 hidden layers of 15 neurons in each of the layers and the RBF had one hidden layer with 100 neurons. The Mean Squared Error and the Mean Bias Error for the TDNN during the training process were 0.0006 and 0.0603 and for the RBF neural network the mentioned errors were 0.0001 and 0.0006, respectively. In the RBF, the coefficient of determination ($R^2$) and the index of agreement (IA) between the observed data and predicted data were 0.997 and 0.999, respectively. In the TDNN, the $R^2$ and the IA between the actual and predicted data were 0.957 and 0.985, respectively. The results of sensitivity illustrated that $Ca^{2+}$ and $SO{_4}^{2-}$ parameters had the highest effect on the TDS prediction.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.181-185
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• 2003

the effect if atmosphere is more important in the West sea of Korea than in other seas because of shallow water and heat storage if the water. The serial oceanographic observation data and coastal station data from NFRID, and the atmosphere data from KMA were used in order to find out the relationship between them The highest water temperature, salinity and weather factor were recorded in Aug, and the lowest of them in Feb. As the water deepens, the maximum time leg in water temperature and the minimum time leg in salinity. Water temperature have the maximum in Oct, the minimum in Apr at 75m of the 311-07 station with 100m depth water temperature (WT)-air temperature, WT-precipitation (Preci.) and salinity (Sal)-wind speed (WS) were in direct proportion, but WT-WS, Sal-AT and Sal-Preci in inverse proportion Water temperature and salinity I-ave time leg at the same depth the maximum had more the delay of $2\~4$ months at a depth if 20 meters than at the surface in all stations except for salinity at 307-05.

• Journal of Korea Multimedia Society
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• v.12 no.1
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• pp.41-49
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• 2009

Smart Card is currently more popular in mobile communication, and smart card with java card platform becomes a standard choice. Java card has a problem that it gets lost working data when power is off. Transaction is the idea to solve a problem of data loss, but it accepts only one transaction process, and other transaction process need to hold until the current working transaction is finished. This might be a factor to drop the Java card's performance. In this paper, we define a rule of dual-lock which can run transaction at multiple transaction buffer as a method for a better java card performance, and we suggest this rule to improve a capability of transaction process. From this research, we are able to improve the data stability, reduce the java card transaction delay time, and get a higher processing speed of java card.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.1-8
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• 2005

Myotonic Dystrophies type 1 and 2 (DM1/2) are neuromuscular disorders which belong to a group of genetic diseases caused by unstable CTG triplet repeat (DM1) and CCTG tetranucleotide repeat (DM2) expansions. In DM1, CTG repeats are located within the 3' untranslated region of myotonin protein kinase (DMPK) gene on chromosome 19q. DM2 is caused by expansion of CCTG repeats located in the first intron of a gene coding for zinc finger factor 9 on chromosome 3q. The CTG and CCTG expansions are located in untranslated regions and are expressed as pre-mRNAs in nuclei (DM1 and DM2) and as mRNA in cytoplasm (DM1). Investigations of molecular alterations in DM1 discovered a new molecular mechanism responsible for this disease. Expansion of un-translated CUG repeats in the mutant DMPK mRNA disrupts biological functions of two CUG-binding proteins, CUGBP and MNBL. These proteins regulate translation and splicing of mRNAs coding for proteins which play a key role in skeletal muscle function. Expansion of CUG repeats alters these two stages of RNA metabolism in DM1 by titrating CUGBP1 and MNBL into mutant DMPK mRNA-protein complexes. Mouse models, in which levels of CUGBP1 and MNBL were modulated to mimic DM1, showed several symptoms of DM1 disease including muscular dystrophy, cataracts and myotonia. Mis-regulated levels of CUGBP1 in newborn mice cause a delay of muscle development mimicking muscle symptoms of congenital form of DM1 disease. Since expansion of CCTG repeats in DM2 is also located in untranslated region, it is predicted that DM2 mechanisms might be similar to those observed in DM1. However, differences in clinical phenotypes of DM1 and DM2 suggest some specific features in molecular pathways in both diseases. Recent publications suggest that number of pathways affected by RNA CUG and CCUG repeats could be larger than initially thought. Detailed studies of these pathways will help in developing therapy for patients affected with DM1 and DM2.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1037-1043
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• 2006

There has been proposed an algorithm to reduce data burst processing delay in group scheduling in core nodes of optical burst switching networks. Since, in this algorithm, look-up tables containing all the void time information in scheduling windows are generated as soon as the primary group scheduling session terminates, it becomes faster to reassign dropped data bursts to proper voids in different data channels by referring to the tables. The group scheduling with this algorithm showed almost the same channel utilization as the one without using the algorithm but performed a little better in both burst loss probability and wavelength conversion rate. On the other hand, per-burst processing time has been reduced dramatically in the load region of higher than 0.8, showing a factor of 2.1 reduction at 0.9.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.120-127
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• 2005

The design method of the transversal filter using continuously cascaded directional couplers is presented. The coupler can be treated for a continuously varying nonuniform coupled transmission line. The design method is based on the optimum extraction of desired coupling factor by the control of null positions which are inherent to the coupling spectra pattern. In the optimization process, the improved Woodward-Lawson sampling method is applied to easily synthesize the distributed delay and weighting elements for transversal filter properties. For application, the microstrip transversal filter is fabricated and optimum dielectric overlay is introduced for the mode phase velocity compensation for non-TEM coupler nodes by using SDA(Spectral Domain Approach). Experiment results confirm the validity of the proposed method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.762-768
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• 2003

This paper reports the effects of gain flatness for linearity improvement of feedforward power amplifier fur IMT-2000 band. To investigate the operational characteristics for gain flatness of each amplifier, WCDMA 4FA input signal was used and measured 10 W output power. Especially, linearity improvement for variation of gain flatness of each amplifier was investigated that have an effect on linearity improvement such as delay line, phase, and amplitude imbalances. Variation of gain flatness of main amplifier is 40 MHz and of error amplifier is 40 MHz and 80 MHz bandwidth, respectively. Measured results, gain flatness of main amplifier is less than 1.5 dB and of error amplifier is less than 0.5 dB for more than 20 dB improvement at 5 MHz offset. In addition to that results, the characteristics of feedforward amplifier are drastically varied by gain flatness of error amplifier and it is shown that gain flatness of error amplifier is more important factor for linearity improvement.