• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.422-425
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• 2008

TerraSAR-X is new radar satellite operated at X-band, multi polarization, and multi beam mode. Compared with C-band or L-band SAR, the X-band system inherently suffers from more temporal decorrelation, but is more sensitive to surface deformation monitoring due to short wavelength (3.1 cm) and high spatial resolution (1m-3m). It is generally expected that sensitivity to estimate surface movement using TerraSAR-X will be increased by the factor of 10, compared to current C-band system with low spatial resolution such as ERS-2, Envisat. Many urban areas are experiencing land subsidence due to water, oil and natural gas withdrawal, underground excavation, sediment compaction, and so on. Monitoring of surface deformation is valuable for effectively limiting damage areas. In addition high accuracy and spatially dense subsidence map can be achieved by X-band InSAR observation, promoting identification and separation of various subsidence processes and leading to enhanced understanding via mechanical modeling. In this study we will introduce some initial InSAR results using new TerraSAR-X SAR data for surface deformation monitoring.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.287-291
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• 2009

The heterogeneous decomposition of ammonia on a quartz surface in an inverted, stagnation-point flow reactor was investigated using a measurement reactor and a numerical model of the reactor. In the experiments, 8 mole% of ammonia in nitrogen was used and the temperature of an electric heater was set in the range $300{\sim}900^{\circ}C$ to heat the quartz surface where the decomposition took place. Gas temperatures and ammonia concentrations in the reactor obtained using in situ Raman spectroscopy were analyzed with the numerical model and it was revealed that, depending on the heater temperature, the temperature of the quartz surface was estimated to be in the range $235{\sim}619^{\circ}C$ and the activation energy of the decomposition on the surface was in the range 10.9~15.8 kcal/mol.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.261-270
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• 2015

Purpose: Cold storage is the most popular method used to preserve highly perishable foods such as beef and fish. However, at refrigeration temperatures, the shelf life of these foods is limited, and spoilage leads to massive food waste. Moreover, freezing significantly affects the food's properties. Ice crystallization and growth during freezing can cause irreversible textural damage to foods through volumetric expansion, moisture migration induced by osmotic pressure gradients, and concentration of solutes,which can lead to protein denaturation. Methods: Although freezing can preserve perishable foods for months, these disruptive changes decrease the consumer's perception of the food's quality. Therefore, the development and testing of new and improved cold storage technologies is a worthwhile pursuit. Results: The process of maintaining a food product in an unfrozen state below its equilibrium freezing temperature is known as supercooling. As supercooling has been shown to offer a considerable improvement over refrigeration for extending a perishable product's shelf life, implementation of supercooling in households and commercial refrigeration units would help diminish food waste. Conclusions: A commercially viable supercooling unit for all perishable food items is currently being developed and fabricated. Buildup of this technology will provide a meaningful improvement in the cold storage of perishable foods, and will have a significant impact on the refrigeration market as a whole.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.31-36
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• 2006

Numerical schemes for spacing and time are tested to accurately simulate the wave propagation. The tested numerical schemesinclude 2nd-order central differencing, l-order upwind scheme, 2nd-order Leith scheme, 3rd-order MUSCLE, QUICK and QUICKEST schemes in spacing and the Euler and 4th-order Runge-Kutta(R-K) schemes in time. It is seen that more accurate results are expected when the higher-order schemes, especially the schemes combined with a TVD control limiter, are used for solving the wave equation. The 3rd-order upwind scheme with limiter and the 4th-order R-K scheme in tim￡ are finally applied to the wave-making simulation in a digital wave tank.

• Journal of Microbiology
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• v.38 no.2
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• pp.53-61
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• 2000

Hydroxybenzoic acids are the most important intermediates in the degradative pathways of various aromatic compounds. Microorganisms catabolize aromatic compounds by converting them to hydroxylated intermediates and then cleave the benzene nucleus with ring dioxygenases. Hydroxylation of the benzene nucleus of an aromatic compound is an essential step for the initiation and subsequent disintegration of the benzene ring. The incorporation of two hydroxyl groups is essential for the labilization of the benzene nucleus. Monohydroxybenzoic acids such as 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 4-hydrosybenzoic acid, opr pyrocattechuic acid that are susceptible for subsequent oxygenative cleavage of the benzene ring. These terminal aromatic intermediates are further degraded to cellular components through ortho-and/or meta-cleavage pathways and finally lead to the formation of constituents of the TCA cycle. Many groups of microorganisms have been isolated as degraders of hydroxybenzoic acids with diverse drgradative routes and specific enzymes involved in their metabolic pahtway. Various microorganisms carry out unusual non-oxidative decarboxylation of aromatic acids and convert them to respective phenols which have been documented. Futher, Pseudomonas and Bacillus spp. are the most ubiquitous microorganisms, being the principal components of microflora of most soil and water enviroments.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.5
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• pp.415-422
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• 2009

This paper describes the UIPV(Utility Interactived Photovoltaic) system which can improve the peak-cut effect by adding energy storage device of batteries to the power converter. The proposed system has three possible operation modes depending on relative condition of PV output, which can have the power shaping function covering the peak power for 3 hours. A new power circuit and application algorithm has been applied to UIPV system which is based on working PV system during 3-hour peak time. The energy relationship by the proposed system is analyzed theoretically and experimentally. Also the proposed system is evaluated at the viewpoint of cost and total spacing, which enables the proposed UIPV system to have the reduction of the peak power demand and hence to improve.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.281-292
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• 2019

This paper proposed a new technology to control a path forging parts in limited narrow space of manufacturing process automation for smart factory. In the motion control, we adapted the obstacle avoidance technology based on ultrasonic sensors. The new motion control performance test for a mobile robot is experimented in narrow space environments. The travelling path control is performed by a fuzzy control logic. which plays a role for selecting an appropriate behavior in accordance with the situation in the vicinity of the mobile robot. Ultrasonic sensors installed at the front face of the mobile robot are used. In order to update the current position and heading angle of the mobile robot, a new approch is adapted. The reliability is illustrated by simulation and experiments.

• Steel and Composite Structures
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• v.32 no.3
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• pp.337-346
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• 2019

The present paper tries to contribute fill the gap of application of the component method to tubular connections. For this purpose, one typical joint configuration in which just one component can be considered as active has been studied. These joints were selected as symmetrically loaded welded connections in which the beam width was the same as the column width. This focused the study on the component 'side walls of rectangular hollow sections (RHS) in tension/compression'. It should be one of the main components to be considered in welded unstiffened joints between I beams and RHS columns. Many experimental tests on double-sided I-beam-to-RHS-column joint with a width ratio 1 have been carried out by the authors and a finite element (FE) model was validated with their results. Then, some different analytical approaches for the component stiffness and strength have been assessed. Finally, the stiffness proposals have been compared with some FE simulations on I-beam-to-RHS-column joints. This work finally proposes the most adequate equations that were found for the stiffness and strength characterization of the component 'side walls of RHS in tension/compression' to be applied in a further unified global proposal for the application of the component method to RHS.

• Earthquakes and Structures
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• v.17 no.3
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• pp.307-315
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• 2019

Building prediction and control theory have been drawing the attention of many scientists over the past few years because design and control efficiency consumes the most financial and energy. In the literature, many methods have been proposed to achieve this goal by trying different control theorems, but all of these methods face some problems in correctly solving the problem. The Evolutionary Bat (EB) Algorithm is one of the recently introduced optimization methods and providing researchers to solve different types of optimization problems. This paper applies EB to the optimization of building control design. The optimized parameter is the input to the fuzzy controller, which gives the status response as an output, which in turn changes the state of the associated actuator. The novel control criterion for guarantee of the stability of the system is also derived for the demonstration in the analysis. This systematic and simplified controller design approach is the contribution for solving complex dynamic engineering system subjected to external disturbances. The experimental results show that the method achieves effective results in the design of closed-loop system. Therefore, by establishing the stability of the closed-loop system, the behavior of the closed-loop building system can be precisely predicted and stabilized.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.213-219
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• 2012

The $5^{th}$ national forest inventory (NFI5) has been reorganized to annual inventory system for providing multi-resources forest statistics at a point in time. The objective of this study is to evaluate statistical estimators for estimating forest growing stock in Chungcheongbuk-Do from annual inventory data. When comparing two estimators; simple random sampling (SRS) and double sampling for post-stratification (DSS), for estimating mean forest growing stock ($m^3/ha$) at each surveyed year, the estimate for DSS in which a population of interest is stratified into three sub-population (forest cover types) was more precise than that for SRS. To combine annual inventory field data, three estimators (Temporally Indifferent Method; TIM, Moving Average; MA, and Weighted Moving Average; WMA) were compared. Even though the estimated mean for TIM and WMA is identical, WMA-DSS is preferred to provide more smaller variance of estimated mean and to adjust for catastrophic events at a surveyed year (so-called "lag bias") by annual inventory data.