• Korean Journal of Pharmacognosy
• /
• v.32 no.1 s.124
• /
• pp.1-5
• /
• 2001

The Chinese crude drug, 'Yong Dam (龍膽)' which is derived from the root of Gentiana plants of the family Gentianaceae, has been used as remedy for stomachic, intestinal catarrh, convulsion, etc. With regard to the botanical origin of 'Yong Dam', it has been considered to be Gentiana species of Gentianaceae, especially Gentiana scabra, but there has no pharmacognostical confirmation on it. To clarify the botanical origin of 'Yong Dam' from Korea, we studied on the anatomical characteristics of Gentiana species growing wild in Korea i.e. Gentiana scabra var. buergeri, G. uchiyamai, G. triflora, G. axillariflora var. coreana and of 'Yong Dam' from Korea on Korean market. Through our studies, the botanical origin of 'Yong Dam' from Korea was proved to be Gentiana scabra var. buergeri and Gentiana axillariflora var. coreana.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.52 no.4
• /
• pp.45-52
• /
• 2010

The purposes of this research are to analyze the internal settlement behavior of Concrete Faced Rockfill Dam (CFRD) typed 'D dam' and to evaluate the stability of the 'D dam' during dam construction using internal settlement measurements and results of numerical analysis. The field measurements were obtained during dam construction period. The numerical analysis was also carried out for the same construction period. The numerical analysis focused mainly on prediction of stress and displacement behavior of 'D dam' during dam construction stage using input parameters obtained from laboratory tests, i.e. large triaxial tests. The behavior of 'D dam' was evaluated to be stable from comparing the results of field measurements and numerical analysis. A simple empirical equation is also presented to predict final settlement at the completion of dam construction, using settlement measurement monitored during dam embankment.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.2
• /
• pp.87-95
• /
• 2013

The aim of this study is to examine the behavior of reservoir fill dam with the water level raising by use of the centrifugal model test and the numerical simulation. In this study, LIQCA2D-SF based on the cyclic elasto-plastic constitutive model proposed by Oka et al. (1999) is applied for numerical simulation. In order to investigate the displacements and the pore water pressures in the fill dam due to the water level raising velocity, three model tests in centrifugal field of 50g for fill dams were conducted. A comparison between the test result and the simulation result has provided the influence on the displacement and the pore water pressure of the fill dam with increasing up of the water level.

• Journal of the Korean Statistical Society
• /
• v.26 no.1
• /
• pp.147-154
• /
• 1997

An infinite dam with a compound Poisson input having exponential jumps is considered. As an output policy, we adopt the $P_{\lambda}$$^{M}$ Policy. After assigning costs to the dam we obtain the long-rum average cost per unit time of operating the dam and find the optimal values of .lambda. and M which minimize the long-run average cost.t.

• Journal of Korean Society of Water and Wastewater
• /
• v.29 no.2
• /
• pp.243-249
• /
• 2015

To improve stability of the water resources that were seriously affected by climate change and various environmental effects and to supply the clean water always, continuous efforts are essential. Provision of measures with respect of hardware is basically essential to improve the water resources stability due to the topographic characteristic in Korea. However, building a new dam becomes gradually very difficult because of a hardship in selecting right places, opposition forces such as environment and local residents, negative publicity for large civil engineering projects, and so on. The present study, therefore, proposes the Blue dam as an alternative for securing the water resources of a new concept considering domestic conditions. To evaluate the effect of the Blue dam, the Hec-ResSim model is used and the probabilistic discharge flow rate is applied. As a result, when Dam Yeongcheon is applied as a study area, securing water resources of 14 million tons are predicted be secured and the flood control of 15.4 million tons is expected, in comparison with operation of the existing dam only. Consequently, Blue dams are supposed to carry out the function of securing water resources, controling flood, maintaining eco-environmental instream flow, generating hydroelectric power, and providing spaces for recreational activities.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.55 no.4
• /
• pp.189-194
• /
• 2006

Dam jerk causes a chronic stomach disorder. The number of the patient of the Dam jerk increase in these days. However, there are no objective and quantitative study for a diagnosis of Dam jerk. Therefore, we designed diagnosis system using ultrasonic response signal for a diagnosis of Dam jerk. It was used to collect the response signal that is reflected at Dam jerk region of the abdominal. And then, the response signal at the Dam jerk region is 20% higher than the normal region. In the result. we could prove the reliability of the system.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1118-1125
• /
• 2005

In this study, seismic safety of CFRD(Concrete-Face Rockfill Dam) type "D" dam in operation is evaluated from the results of 1-g shaking table test using similitude laws. Model dam is made by similitude law considering the grain size of prototype dam component. After the model dam is impounded to the normal water level(N.W.L), it is excited by artificial earthquake wave corresponding to standard design respond spectrum of the "D" dam site. Displacement response behavior of the dam is examined through the measurement of vertical and horizontal displacement of dam crest. Also, amplification characteristics of acceleration with dam height is examined through the measurement of acceleration with dam height. Finally, the purpose of this study is to evaluate seismic safety of "D" dam in operation. From the results of acceleration measurement, it was found that acceleration of dam crest was amplified about 1.52 times compared to the acceleration of dam bottom and amplification phenomenon is outstanding at three quarters of dam height from the bottom of dam. From the analysis of displacement behavior, it was estimated that vertical displacement of prototype dam is 6.8cm (0.1% of dam height) and horizontal displacement 12.3cm(0.2% of dam height). These percentages is much lower than 1% of dam height(general stability criteria). Therefore, it was concluded that seismic stability of "D" dam against an estimated earthquake is guaranteed.

• Proceedings of the KIEE Conference
• /
• 2006.10b
• /
• pp.185-190
• /
• 2006

Frequency and phasor are the most important quantities in power system operation because they can reflect the whole power system situation. Frequency reflects the dynamic energy balance between load and generating power, while operators use phasor to constitute the state of system and, moreover, phasor based line relays are currently used in most power systems. So frequency and phasor are regarded as indices for the operating power systems in practice. The proposed technique is suitable for estimation near-nominal, nomina), and off-nominal frequencies. It is useful in designing microprocessor-based relays and meters that need to measure power system frequency. Performance test results, using signals from EMTP source and Excel program, indicate that the proposed technique can provide accurate estimates within 16ms. Maximum estimation errors observed during testing are of the order of 0.006Hz for nominal, near-nominal, and off-nominal frequencies. The proposed technique provides accurate estimates in presence of noise and harmonics and in case ground fault. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2005.03a
• /
• pp.3-10
• /
• 2005

In this study, 1-g shaking table tests on the model of CFR(Concrete-Face Rockfill) type "D" dam in operation and the model of virtual ECRD(Earth Core Rockfill Dam) of which static stability is about the same compared to the model of CFRD were carried out. The purpose of this study is to compare the seismic performance of CFRD and ECRD from the analysis of model test results. Displacement response behavior of the dam was examined through the measurement of vertical and horizontal displacement of model dam crest. Also, amplification characteristics of accelerometers installed with dam height were examined through the measurement of acceleration with dam height. Also, in the case of ECRD, patterns of excess pore pressure generation with dam height were examined. From the test results, it was found that accelerations of dam crest of CFRD and ECRD were amplified about 1.52 times and 2 times compared to the accelerations of dam bottom, respectively. amplification was outstanding at three quarters of dam height from the bottom of dam. This phenomenon was outstanding in case of ECRD. And it was estimated that vertical and horizontal displacement of prototype dam of CFRD were 6.8cm (0.1% of dam height) and 12.3cm (0.2% of dam height), respectively. Also, it was estimated that vertical and horizontal displacement of prototype dam of ECRD were 4.3cm (0.1% of dam height) and 5.5cm (0.11% of dam height), respectively.

• Proceedings of the KIEE Conference
• /
• 2005.10a
• /
• pp.145-149
• /
• 2005

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.