• Transactions on Electrical and Electronic Materials
• /
• v.17 no.2
• /
• pp.92-97
• /
• 2016

This paper presents design and simulation of wide band RF microswitch that uses electrostatic actuation for its operation. RF MEMS devices exhibit superior high frequency performance in comparison to conventional devices. Similar techniques that are used in Very Large Scale Integration (VLSI) can be employed to design and fabricate MEMS devices and traditional batch-processing methods can be used for its manufacturing. The proposed switch presents a novel design approach to handle reliability concerns in MEMS switches like dielectric charging effect, micro welding and stiction. The shape has been optimized at actuation voltage of 14-16 V. The switch has an improved restoring force of 20.8 μN. The design of the proposed switch is very elemental and primarily composed of electrostatic actuator, a bridge membrane and coplanar waveguide which are suspended over the substrate. The simple design of the switch makes it easy for fabrication. Typical insertion and isolation of the switch at 1 GHz is -0.03 dB and -71 dB and at 85 GHz it is -0.24 dB and -29.8 dB respectively. The isolation remains more than - 20 db even after 120 GHz. To our knowledge this is the first demonstration of a metal contact switch that shows such a high and sustained isolation and performance at W-band frequencies with an excellent figure-of merit (fc=1/2.pi.Ron.Cu =1,900 GHz). This figure of merit is significantly greater than electronic switching devices. The switch would find extensive application in wideband operations and areas where reliability is a major concern.

• Journal of Convergence for Information Technology
• /
• v.8 no.1
• /
• pp.201-206
• /
• 2018

Recently, as technologies for realizing artificial intelligence have become more common, machine learning is widely used. Machine learning provides insight into collecting large amounts of data, batch processing, and taking final action, but the effects of the work are not immediately integrated into the learning process. In this paper proposed an adaptive learning model to improve the performance of real-time stream analysis as a big business issue. Adaptive learning generates the ensemble by adapting to the complexity of the data set, and the algorithm uses the data needed to determine the optimal data point to sample. In an experiment for six standard data sets, the adaptive learning model outperformed the simple machine learning model for classification at the learning time and accuracy. In particular, the support vector machine showed excellent performance at the end of all ensembles. Adaptive learning is expected to be applicable to a wide range of problems that need to be adaptively updated in the inference of changes in various parameters over time.

• Spatial Information Research
• /
• v.17 no.2
• /
• pp.213-222
• /
• 2009

Finding exclusive closest pairs in road network is very useful to real applications such as, for example, finding a closest pair between a passenger and a nearby taxi in a road network. Few studies, however, have been interested in this problem. To match two close moving objects exclusively, one object must belong to only one result pair. Because moving objects in a road network change their position continuously, it is necessary to monitor closest pair results. In this paper, we propose a methodology to monitor k exclusive closest pairs via a road network. Proposed method only updates the results which are influenced by objects' movement. We evaluated the performance of the proposed method with various real road network data. The results show that our method produces better accuracy than normal batch processing methods.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.3 s.30
• /
• pp.91-97
• /
• 2004

As for the former analogue method of photogrammetry, We have obtained final digital drawing by creating the stereo model from overlapped images through orientation process using plotting instrument and processing restitution procedure. However, digital photogrammetry batch processes such using small computer system thus We make an attempt automatization of the procedures. And without the production of stereo model, We could obtain 3D digital data through analysis method. Therefore, an objective of this study was to implement a surveying system that could 3D surveying positions using the digital image to reduce limitations of control point surveying and photographing conditions more efficiently to produce digital drawing. By the result, photogrammetry can practice and make out digital drawing to a computer by digital camera of a comparative low-cost. Small scale area can become practical use to drawing production etc. for facilities management because area can make out digital drawing economically than general surveying.

• Polymer(Korea)
• /
• v.38 no.2
• /
• pp.225-231
• /
• 2014

The rheological properties of highly concentrated polymer bonded explosive simulant were studied by using poly(ethylene-co-vinyl acetate) with 30 and 60% vinyl acetate (VA) content as a binder, respectively. Calcium carbonate and Dechlorane, whose physical properties are similar to resarch department explosive (RDX)'s, were used as fillers. The suspensions were mixed in a batch melt mixer and it was possible to fill 75 v% at maximum. From dynamic mechanical analysis, Dechlorane showed higher interaction with binder resins than that with calcium carbonate fillers. The effects of microstructural change on the rheological properties of the suspensions were investigated by a plate-plate rheometer with constant shear rate and constant shear stress modes, respectively. The theoretical maximum packing fraction of EVA31/Dechlorane suspension obtained from Krieger-Dougherty equation was 70 v% and it was thought that 2000 Pa was proper shear stress condition for this melt processing.

• Membrane Journal
• /
• v.8 no.1
• /
• pp.29-41
• /
• 1998

Thin-film composite reverse osmosis membranes of aromatic polyamides were prepared by the interfacial polymerization. Aromatic polyamides as active skin layer were made from the interfacial polymerization of MPD(m-phenylene diamine) in the aqueous and TMC(trimesoyl chloride) in HCFC(1,1-dichloro-1-fluoroethane) organic solvent. The performances of the various reverse osmosis composite membranes prepared by changing processing variables were examined. The performance of membrane manufactured by batch system was varied with organic solvent, monomer concentration, dipping time, heat treatment temperature, acid acceptor, ethanol post treatment, and acid post treatment. Ethanol post treatment was the most dominant factors in increasing permeate amount, while the monomer concentration and dipping time were the main factors in increasing selectivity. The spiral-wound module was produced with the membrane prepared at optimum condition of the continuous process. Comparing the performance of this membrane module made here with that of commercial membrane module, the permeate flux was increased by 33% while the rejection was decreased by 5%.

• Korean journal of food and cookery science
• /
• v.23 no.2 s.98
• /
• pp.221-226
• /
• 2007

This study was carried out to investigate the optimun conditions for the isolation of low molecular weight peptides containing histidine, and to evaluate the antioxidant effects of skipjack boiled extracts(SBE). The results are summarized as follows : L-histidine contents of the ordinary muscle and dark muscle extracts were $ 83.1{\pm}1.75{\mu}M/g\;and\;11.0{\pm}2.39\;{\mu}M/g$, respectively. The L-histidine level of the dark muscle was much lower than that of ordinary muscle in the SBE. The extracts were treated with alcalase and neutrase under different pH levels, temperatures, and times. The optimum hydrolysis conditions of SBE were pH 7.0 and a $60^{\circ}$C temperature for 2 hr in the batch reactor, which hydrolyzed 63% of the SBE. HPLC analysis showed a removing effect of the ultrafiltration permeate (UFP) to high molecular weight impurities in SBE. SBE and pure carnosine participated as inhibiting agents to, which was confirmed through the autoxidation processing of linoleic acid. UFP treatment improved the inhibiting ability of SBE to the autoxidation of linoleic acid. The reducing power of the UFP-treated ordinary muscle extracts were 10-fold higher than the dark muscle extracts, and 0.7-fold higher than 20 mM pure carnosine. The UFP-treated ordinary muscle extracts had greater reducing power activity than pure carnosine. The scavenging activities on DPPH radical of the different treated-SBE and pure carnosine were also investigated. Scavenging activities of the ordinary and dark muscle extracts and the pure carnosine were 90%, 70%, and 45%, respectively. In summary, Skipjack boiled extracts (SBE) demonstrated that low molecular weight peptides containing histidine are capable of inhibiting lipid oxidation. They also possessed effective abilities as free radical scavengers and reducing agents, and these activities may increase with increasing concentrations.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.27 no.4
• /
• pp.291-301
• /
• 2017

Objectives: In order to improve the working environment and solve the complaints, many efforts have been made to remove the odor from the industrial process. There are many disposal methods to remove odor, but there are many disadvantages and inadequate applications. The Purpose of this study was to develop a bag-filer system for odor removal using powder adsorbent. Methods: The bag-filter system is composed of a shear bag filter, an absorbent spraying system and an absorbent circulation system. The spraying absorbent system was connected with the inlet duct of the shear bag filter for inputting adsorbent. And the absorbent circulation system can transport the collecting adsorbent from hoper to the inlet duct of the system. As a result, the adsorbent can remove odor with recycling in the system. Also affective factors like the powdered absorbent combination and injection method was researched for maximization of system efficiency. The study was conducted in two stages. The first step was testing equipment made and the second is to evaluate the efficiency of the odor control by connecting to the actual odor generation process. Results: Both experiment stages showed efficient odor control ability. The adsorption efficiency of the system is demonstrated and the odor was adsorbed well by the powder adsorbent. It is essential to accurately understand the characteristics of the odorous and use the appropriate adsorbent. Although the powder adsorbent was used in the experiment, the problem of scattering did not occur due to the high degree of system sealing. Also the system manufactured in this study was designed to recycle the adsorbent, so adsorbent reuse or batch processing is convenient. Conclusions: The applicability of the system has been proven through this research. Customized systems for industrial process and the appropriate adsorbent base on the characteristics of pollutant generation will show efficient odor collection ability.

• Journal of Korean Society on Water Environment
• /
• v.24 no.1
• /
• pp.30-35
• /
• 2008

In this study, we investigated the nitrification/denitrification rate and classification of output nitrogen of a sequencing batch reactor (SBR) system with the variation of COD loads ; COD loads of 0.3, 0.4, 0.6, 0.7, 0.8, 1.0 and $1.2kgCOD/m^3{\cdot}d$ were tested to determine the optimum conditions for the operation of the SBR and increase its nitrogen removal efficiency. As the COD loads increased, the nitrification rate at aerobic(I) period and the denitrification rate at anoxic(I) period were decreased. With the variation of COD loads, the amounts of nitrogen removed in the clarified water effluent were 63.9, 54.2, 34.7, 22.5, 13.7, 12.5 and 26.5 mg/cycle, respectively. The amounts of nitrogen removed during the sludge waste process were 19.5, 26.6, 41.0, 47.3, 58.1, 72.4 and 88.1 mg/cycle, respectively. The amounts of nitrogen removed by denitrification were 66.8, 69.3, 68.9, 56.5, 39.5, 7.3 and 0.0 mg/cycle, respectively, indicating that COD load more than $0.7kgCOD/m^3{\cdot}d$ decreases the amounts of denitrified nitrogen. The nitrogen mass balances were calculated as the percentages of nitrogen removed in the clarified water effluent or by denitrification and sludge waste processing in each cycle of SBR operation and were 99.0, 98.5, 95.4, 82.1, 73.0, 60.5 and 74.8% for COD loads of 0.3, 0.4, 0.6, 0.7, 0.8, 1.0 and $1.2kgCOD/m^3{\cdot}d$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.3
• /
• pp.207-212
• /
• 2001

Supercritical fluid extraction was explored as a method for removing lipids and bad odor from tuna viscera. Selected conditions of extraction pressure, time, temperature and sample size were evaluated for effective removal of lipids and bad odor, Supercritical carbon dioxide was used as a solvent and the extraction was performed at semi-batch flow type. The experimental conditions used in this work was the range of pressure from 1,500 psig to 2,000 psig, the temperature from $25^{\circ}C\;to\;40^{\circ}C$ and dried sample size from 0.2 mm to 1.0 mm. The main fatty acids extracted from tuna viscera were palmitic acid (16: 0) heptadecenoic acid (17: 1) oleic acid (18: 1) and docosahexaenoic acid (22: 6). Protein concentrate was obtained without deformation the optimum condition at $35^{\circ}C$, 1,800 psig and 0.25 mm of the size. In the concentrate after supercritical carbon dioxide extraction, the major amino acids were glutamic acid, leucine and lysine.