• YAKHAK HOEJI
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• v.57 no.2
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• pp.119-124
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• 2013

The aim of this present study was to investigate the antifungal effect of tanshinones isolated from Salvia miltiorrhiza against Candida ablicans, a polymorphic fungus. For the work, tanshinone IIA (TSN), cryptotanshinone (CTS), and dihydrotanshinone I (DTS) were chosen. Initially, their antifungal effect was analyzed by in-vitro susceptibility test. Data from the susceptibility test showed that while all of these three compounds had antifungal activity, DTS was the most potent. At $100{\mu}g$ DTS/ml, there was about 80% CFU (colony forming unit) reduction as compared to DTS-untreated C. albicans yeast cells (P<0.05). Thus, DTS was selected to determine its antifungal activity in a murine model of disseminated candidiasis due to C. albicans. Results showed that DTS enhanced resistance of mice against disseminated candidiasis. During the entire period of 30-day observation, 60% of DTS-given mice groups survived whereas control animals all died within 14 days (P<0.05). Moreover, DTS inhibited the hyphal production, one of the virulence factors of this fungus, from the blastoconidial form of the fungus. Therefore, the tanshinone appears to have antifungal activity specific for C. albicans infection, which could possibly be mediated by the blockage of hyphal production.

• KSBB Journal
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• v.26 no.5
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• pp.433-438
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• 2011

These studies were conducted to investigate the alcohol degradation effects of the extract of herbal composition (DTS20) containing Viscum album L., Lycium chinense L., Inonotus obliquus and Acanthopanax senticosus H., on the alcohol administered mice. To investigate anti-hangover effect, alcohol and alcohol dehydrogensae (ADH) concentration of blood were measured after oral administration of ethanol. The administration of DTS20 (200-500 mg/kg) had beneficial actions toward alcohol degradation in acute alcohol treated mice model. The oral administration of DTS20 showed decreased gastric mucous membrane damage produced in ethanol treated mice. In addition, intraperitoneal administration of DTS20 showed anti-inflammatory effects in inhibition tests of vascular permeability produced by acetic acid. DTS20 also reduced the concentration of nitric oxide (NO), tumor necrosis factor (TNF)-${\alpha}$ in macrophages that were activated by LPS. These results demonstrate that DTS20 possesses potential to stimulate the alcohol degradation and inhibit the inflammatory effects in mice.

• Fire Science and Engineering
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• v.30 no.4
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• pp.27-38
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• 2016

The paper reports the development of a distributed temperature sensing (DTS) system, which is a fire detection system using optical sensor linear detectors that depends on foreign and domestic technologies. This study accordingly analyzed the electrical signal patterns of Raman scattering light mainly used for temperature sensing among back-scattered light generated in optical fiber by using an oscilloscope. Through the measurement results, it could be verified that the Stokes signal patterns had little change by the temperature increase, but the temperature-sensitive anti-Stokes patterns had relative increase of the changes. This study developed a K-DTS system, which is an optical sensor linear fire detection system composed of an optical repeater and a receiver that can detect fires using Raman scattering light. It could be verified that the developed K-DTS system satisfied the type approval standards through the sensitivity tests using the rate of rise type and fixed temperature type sensitivity testers. In addition, performance experiments have been performed for performance evaluation of the K-DTS system developed in comparison with S-DTS system which has been imported from abroad and widely used in Korea. It can be confirmed from the results of the performance experiments using model tunnels that comparable performances can be obtained in fire detection locations and the measurements of fire temperatures.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1547-1550
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• 2015

Fuji apple variety introduced in Japan has excellent storage quality and good taste so it is most commonly cultivated in the Korean Peninsula. Accurate prediction of harvest maturity allows farmers to more efficiently manage their farm, such as working time, fruit storage, market shipment and labor distribution so it is very important. This study was carried out to predict the harvest maturity of 'Fuji' apple using DTS (Days Transformed to Standard temperature) model based on the Arrhenius law in the Gunwi province of the South Korea. Input data are daily average temperature and apple harvest maturity. Predicted the harvest maturity of Fuji apple after estimating the optimal parameters by using the Nelder-Mead method. The differences of observed and predicted harvest maturity day are approximately 1 to 4 days and the RMSE is 2.9.

• International Journal of Contents
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• v.8 no.2
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• pp.23-27
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• 2012

The successful use of digital textbooks (DTs) in schools requires the development of various teaching and learning methods that are appropriate for DTs. However, recent DT studies have focused mainly on the implementation of DT features and formats. The objective of this study was to investigate a problem-based learning instructional model appropriate to DTs and to present the experimental results using the problem-based DT to demonstrate its educational effectiveness. Two learning-achievements tests were conducted to analyze the learning experience and effectiveness of the problem-based DT after it had been used in a high school for a certain period. The experimental results indicated that the students who used the DT, especially lower-level students, exhibited improved problem-solving ability and demonstrated a better practical understanding of the subject than students who used printed textbooks.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.5-22
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• 2021

Digital Twin for Land(DTL) is one of the national work projects in the Korean New Deal but there aren't still any standards and technical guides which would need to construct the DTL. This study presents the policies to develop reference model and data model based on geo-spatial information standards to ensure interoperability for the DTL. In this paper, we first extract the implications through reviewing definitions of Digital Twin used in various literatures and international standardization trends on Digital Twin. In addition, this study attempts to conceptualize the DTL through various ways such as defining the DTL and characterizing DTL domains. Finally, we propose three policies on the standardization of the DTS: (1) DTS reference model by using RM-ODP, (2) three-steps hierarchical data models, and (3) model registry to manage the data models efficiently. The proposed policies of the study would contribute to establish a way for DTS's standards development over the coming years.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.30-34
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• 2005

Due to old Toshiba EMS's database size limit and hardware old aging, KPX(Korea Power Exchange) had introduced New EMS from AREVA(old ALSTOM) in July 2002. After then KPX had committed many man power and time to normalize EMS NA(Network Analysis) functions for using real power system. At initial stage, to normalize State Estimator which is the backbone of all other NA functions and DTS(Dispatcher Training Simulator}, KPX had corrected numerous topology errors, network model errors, non-scanned and wrongly scanned SCADA measured errors. After SE function study, running test and tuning, State Estimator could finally have been run properly and stably from June 2003. Based on SE running, KPX had normalized real time Contingency Analysis, and study mode Power Flow, STNET and DTS. From early 2004, dispatchers have been trained to use NA and DTS for the purpose of stable SE running, NA operation & results reading and urgent equipment outage reviewing. EMS NA have been greatly contributed to operate real time power system stably. Above NA normal operation by KPX own efforts under the no experience of NA running, KPX made a good precedent. This paper is intended to introduce EMS NA normalization process, operation status, and etc in Korea power system operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.492-498
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• 2010

Since it is almost impossible to train the dispatchers with real power system, the dispatcher training simulator(DTS) is used for the training. Among various components of the DTS, the power system model(PSM) emulates the dynamic behavior of the power system to calculate the frequency and voltage. The frequency is calculated from various parameters such as mechanical power of power plants, load, inertia, and the damping of the power system. In the PSM, the power plants are modeled as differential equations, so the mechanical power of the power plants are calculated by the numerical methods. Conventionally, the fixed step-size algorithm has been used in the PSM, however it has some drawbacks. This paper develops the prototype PSM using the Matlab, and analyzes the problems of the fixed step-size algorithm by comparing the results with those of PSCAD simulation. In order to overcome the limitations, this paper proposes a modified frequency calculation method using the adaptive step-size algorithm. From the simulation using the proposed method, it is verified that the accuracy of frequency calculation increases substantially while the simulation time is not greatly increased.

• Journal of the Korean GEO-environmental Society
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• v.16 no.6
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• pp.39-43
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• 2015

This study extends the Distributed Temperature Sensing (DTS) application to delineate the saturated zones in shallow sediment and evaluate the groundwater flow in both downward and upward directions. Dry, partially and fully saturated zones and water level in the subsurface can be recognized from this study. High resolution seepage velocity in vertical direction was estimated from the temperature data in the fully saturated zone. By a single profile, water level can be detected and seepage velocity in saturated zone can be estimated. Furthermore, thermal gradient analysis serves as a new technique to verify unsaturated and saturated zones in the subsurface. The vertical seepage velocity distribution in the recognized saturated zone is then analyzed with improvement of Bredehoeft and Papaopulos' model. This new approach provides promising potential in real-time monitoring of groundwater movement.

• Ocean Systems Engineering
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• v.7 no.1
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• pp.21-38
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• 2017

In real sea environments, excessive dynamic axial tension variations can be exerted on the top-tensioned risers (TTRs) and lead to structural integrity issues. The traditional riser-tension-variation analysis, however, by using parametric formulation is only conditionally valid under certain strict limits and potentially underestimates the total magnitudes of tension variations. This phenomenon is especially important for the long stroke tensioner in dry-tree semisubmersible with larger global heave motion and longer stroke. In this paper, the hydro-pneumatic tensioner (HPT) is modeled in detailed component-level which includes a set of hydraulic and pneumatic components. The viscous fluid frictional effect in the HPT is considered. The main objectives are (i) to develop a detailed tension variation model of the HPT; (ii) to identify the deviations between the conventional parametric formulation and component-level formulation; (iii) to numerically analyze the tension variation of long stroke tensioner in a dry-tree semisubmersible (DTS). The results demonstrate the necessity of component-level formulation for long stroke tensioner in the development of DTS.