• KIPS Transactions on Software and Data Engineering
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• v.9 no.5
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• pp.153-160
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• 2020

Energy Consumption Predictions for Industries has a prominent role to play in the energy management and control system as dynamic and seasonal changes are occurring in energy demand and supply. This paper introduces and explores the steel industry's predictive models of energy consumption. The data used includes lagging and leading reactive power lagging and leading current variable, emission of carbon dioxide (tCO2) and load type. Four statistical models are trained and tested in the test set: (a) Linear Regression (LR), (b) Radial Kernel Support Vector Machine (SVM RBF), (c) Gradient Boosting Machine (GBM), and (d) Random Forest (RF). Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) are used for calculating regression model predictive performance. When using all the predictors, the best model RF can provide RMSE value 7.33 in the test set.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.683-684
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• 2004

The RF system for PEFP 20MeV proton linear accelerator is described. The RF system for 3MeV RFQ was already installed and operated to drive the RFQ. The klystron was tested up to 600kW itself and operated up to 350kW routinely. The HPRF dummy load was stabilized with the change of the coolant. Preparation of 20MeV DTL HPRF test has been completed. LCP and PLC system for klystron power supply was already prepared. Voltage fluctuation was measured during klystron test. Voltage control feedback loop seems to be re-adjusted.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.269-272
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• 2007

In order to expand cell coverage, increase system capacity, and offer various multimedia service with high throughput in indoor environment, WiBro Access Point(AP) is developed. Home AP is IFA/Omni type and has stack-up structure of channel card and RF board. SOHO AP is designed to support up to 2FA and has remote RF(RRF) structure using UTP method. Inter-operational test with mobile terminal were completed for 3 terminals using web browsing service simultaneously. The performance test results of WiBro AP are as follows: RCE(EVM) value is -34.431 dB for 64-QAM and throughput is up to 6.79 Mbps(DL) and 1.1 Mbps(UL) with 2.5m Line-of-Sight(LOS) condition.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.771-778
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• 2006

Before the Flap type GATE is introduced until, the Turnstile type GATE was plentifully used. The Turnstile type GATE is used plentifully from the Seoul metro, Busan Transportation Corporation and Korea Railroad Corporation. From the Turnstile type GATE, the micro switch breakdown is occurred by the contact of the micro switch which perceives a Turnstile rotation and the cam. The breakdown is cause of the passenger inconveniently. In order to prevent the breakdown which is caused by Micro switch contact, Microswitch support used the sensor in Turnstile rotation perception. The sensor which is used in test is Photo Sensor and Reed Sensor two type. The test result Reed Sensor was suitable in underground environment. When using the RF card, RF card processing came to be quick

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.16-20
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• 1986

The major pungent component from Korean radish roots was purified by reverse phase high performance liquid chromatography (RPHPLC), and characterized as 4-methylthio-3-butenyl isothiocyanate on the basis of the sensory test (pungency), UV spectrum and mass spectrum analysis. The purified isothiocyanate moved as a single peak(retention time, 5.2 min) in RP-HPLC analysis, and as a single spot(Rf, 0.9) in TLC analysis.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.215-217
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• 2010

This paper describes the test results of radiated compatibility with Ariane 5 launcher performed on the COMS Satellite test facility. Firstly, the Radiated Emission test results are analyzed in compliance with the Radiated Susceptibility requirement specification of Ariane 5 launcher. The satellite nominal operation is monitored during injection a radiated electric field corresponding to the launcher emissions levels in critical frequency ranges. And also, E-field are measured through a probe located at external units level in order to assess the EMC safety margin in Radiated mode.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1937-1941
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• 2004

We present lateral actuated piezoelectric actuator using U-shaped PZT strip and lever structure for the RF switch application. In the previous study of RF switch, they used horizontal contact switch fabricated by thin film metals. However, thin film metals could not generate large contact force due to low stiffness. In this work, we suggest lateral contact switch which makes large contact force by increasing stiffness. In addition, we use PZT actuator for the high force actuation. Generally actuator using thin film PZT moves to the vertical direction due to the neutral axis shift. Therefore we need lateral motion generation mechanism based on the thin film PZT actuator. In order to increase lateral motion of thin film PZT actuator, we use U-shaped PZT actuator using residual stress control. Also, thin film PZT actuator can generate very small lateral motion of 120${\times}$10$^{-6}$ ${\mu}{\textrm}{m}$/V for d$_{31}$ mode, thus we suggest lever structure to increase stroke amplification. From the experimental study, fabricated PZT actuator shows maximum lateral displacement of 1 ${\mu}{\textrm}{m}$, and break down voltage of the thin film PZT actuator is above 16V.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.579-586
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• 2005

Recently, it has demanded to the wireless monitoring system in stand-alone PV power generation system. We propose the multiplex monitoring method using RF unit of low-price. RF unit consists of RF modem and communication controller. It is also able to use by repeater to communicate long distance. In this paper. two algorithms were programmed by CCS-C and C++ for multiplex monitoring method, The algorithm of choosing unit was used 'select and poll method' and the course assignment algorithm was embodied with 'Bellman-Ford algorithm'. The good result was achieved in the actual test without communication-data lose. The proposed method will be applied such as monitoring system of PV light on the wayside, monitoring system of unmanned lighthouse, monitoring system of refrigeration container on vessel and so on. It can be applied in the field that various ocean energy system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1091-1096
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• 2010

Stiction in microelectromechanical systems (MEMS) has been a major failure mechanism. Especially, in RF MEMS switches, moving parts often suffered in-use and release related stiction problems. Some materials and methods have been used to prevent this problem. Diamond-like carbon (DLC) has not only been used as a protective material owing to its good mechanical properties but also has been used as a hydrophobic material. Its properties could be controlled by post annealing treatment in various conditions. We synthesized DLC films using a radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gas. Then, the change of the hydrophobic property of the films was investigated undervarious annealing temperatures in nitrogen and in oxygen ambient. The films, that were annealed above $700^{\circ}C$ in nitrogen ambient, showed a high contact angle of water (> $90^{\circ}$) even though their mechanical property was sacrificed to some degree. The structural variation and the changes of the hydrophobic and mechanical properties of the DLC films were analyzed by Raman spectrum, contact angle measurement, surface profiler, and a nanoindentation test.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1972-1975
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• 2002

In this paper, we have proposed low temperature co-fired ceramic (LTCC) based packaging for RF MEMS devices. The packaging structure is designed and evaluated with 3D full field simulation. 50 ${\Omega}$ matched coplanar waveguide(CPW) transmission line is employed as the test vehicle to evaluate the performances of the proposed package structure. The line is encapsulated with the LTCC packaging lid and connected to the via feed line. To reduce the insertion loss due to the packaging lid, the cavity with via post is formed in the packaging lid. The performances of the package structure is simulated with the different cavity depth and via-to-via length. Simulation results show that the proposed package structure has reflection loss better than 20 dB and insertion loss lower than 0.1 dB from DC to 30 GHz with the cavity depth and via-to-via length of 300 ${\mu}m$ and 350 ${\mu}m$, respectively. To realize the designed package structure, the cavity patterning is tested using the sandblast of LTCC.