• Nuclear Engineering and Technology
• /
• v.52 no.3
• /
• pp.654-659
• /
• 2020

The reliability of the spent fuel pool instrument is very important for the security of nuclear power plant, especially during the earthquake. The effect of the fluid force on the vibration characteristics of the flexible tube of the spent fuel pool instrument needs comprehensive analysis. In this paper, based on the potential flow theory, the hydrodynamic pressures acting on the flexible tube were obtained. A mathematical model of a flexible tube was constructed to obtain the dynamic response considering the effects of seismic load and fluid force, and a computer code was written. Based on the mathematical model and computer code, the maximum stresses of the flexible tube in both safe shutdown earthquake and operating basis earthquake events on the spent fuel pool with three typical water levels were calculated, respectively. The results show that the fluid force has an obvious effect on the stress and strain of the flexible tube in both safe shutdown earthquake and operating basis earthquake events.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.04a
• /
• pp.458-467
• /
• 2000

The standard of performance-based seismic design accepted by Ministry of Construction and Transport requires to install and manage earthquake instruments for the facilities of seismic category I and to acquire earthquake response data of these facilities at earthquake events. So detailed standard and guideline for installation and management of earthquake instruments for each facilities according to the seismic design standard are getting ready. This paper presents the part of installation locations of sensors in that detaile standard and guideline.

• Journal of the Korean Society of Safety
• /
• v.17 no.1
• /
• pp.79-86
• /
• 2002

In the case of earthquake, it is necessary to install earthquake instruments and to measure the ground motions for stable gas supply and restoration in case of supply suspension. Because each point in the site of the gas facilities has different characteristics of ground motion, it is recommended to measure at the point where the ground motion is representative. In this paper, ground motion analysis and noise pattern analysis are carried out to select suitable point for the installation of earthquake instruments and to set of dynamic range of sensors.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.11-18
• /
• 2001

A close examination of the step calibrations for STS-2 seismometers installed by KMA has been done to deduce the response parameters of those instrument including angular corner frequency, damping factor and coil constant factor. A non-linear least square inversion method has been apple iud to estimate these parameters. The estimated parameters coincide with the manufactory specification with less than 1% error. This method will be extended near- future to deduce the response parameters for SS-1 short period seismometer.

• Explosives and Blasting
• /
• v.32 no.1
• /
• pp.18-22
• /
• 2014

KoRail establishes "Guideline for earthquake acceleration measuring instrument and operation." and applies the management of the rapid transit railroad. KoRail manages the trains by train driving patterns subjected to the train operating know-how for the safety against the earthquake hazards. This paper introduces the case studies on bench blast and tunnel blast designs considering a rapid transit railroad.

• Economic and Environmental Geology
• /
• v.34 no.6
• /
• pp.573-581
• /
• 2001

110 earthquake parameters (origin time, epicentral location and magnitude) were determined from 533 event records between 1905 and 1942 using data mainly from the "Annual Report of the Meteorological Observatory of the Government General of Tyosen" We adopted epicentral coordinates from the original reports for 34 events and from the Japanese Central Meteorological Observatory far another .34 events. We determined epicenters for 37 events using arrival time information from the reports. We adopted 4 epicenters from the International Seismological Summary and I from the Chinese bulletin. To determine the magnitude, we applied Tsuboi (1954) formula which is currently employed by Korea Meteorological Administration (KMA) for 94 events. For 16 events, we determined magnitude from the reef)reed felt epicentral areal using the correlation equation between known magnitude and felt area.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1588-1595
• /
• 2005

In this study, the installation location of accelerometer and accelerograph for dam are investigated in the field to establish of emergency action against dam failure when earthquake occur and to guarantee the results of seismic stability of dams which are analysed with dynamic analysis method during 1999 to 2003 by KOWACO. By a comparative study concerning of domestic and foreign guidelines of seismic strong motion instrumentation for dams, "Guidelines of Seismic Strong-Motion Instrumentation Installation, Operation and Maintenance for Dams" is established to set up the standard of seismic strong-motion instrumentation for dam, are supervised by KOWACO There is some problems in taking a measure of stability of dams when earthquake event occur because the existing seismic strong motion instruments are operated independently. This make difficult to confirm the occurrence of seismic event. For that reason, in this study the plan of unified operation and maintenance system for strong-motion instrument for dams is designed. It will make possible real-time seismic monitoring, data transmission and receiving, giving warning for earthquake, and exchanging data with national seismic network.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.73-80
• /
• 2000

The distance correction term -logA0 of the local magnitude scale was estimated for earthquakes in southern Korea using linear least-squares inversion and interpolation scheme. Total 1054 short-period velocity seismograms from 107 local events recorded at hypocentral distances ranging from 10 to 480 km were used in this study. Simulated Wood-Anderson amplitudes were obtained from velocity seismograms with use of revised Wood-Anderson instrument response with static magnification 2080, damping factor 0.7, and natural period 0.8 sec. The estimated distance correction term for southern Korea is found to be -logA0=1.137 log(r/17) + 0.001159(r-17) + 20, where r is hypocentral distance in kilometers. The attenuation rate of this distance correction term falls between those of southern California and eastern North America.

• The Journal of the Korean dental association
• /
• v.48 no.12
• /
• pp.893-918
• /
• 2010

This article is purposed of reviewing the development history of Japanese dental devices and instrument, and their related advertisement activities during the Japanese colonized period in Korea in early 20th century. Japanese dental devices and instrument were redesigned to accommodate their ergonomic shape above the simple imitation, and it implies the excessive desires brought them frustrations. The tragic earthquake on Sep. l, 1923, medical insurance law enforcement on Jan. 1, 1927, celebration of "Cavity prevention Day" started on Jun. 4, 1928, and the attack of Manchuria and China by Japan after 1931, all of these historical incidents become the preliminary requirement for the development of dental devices. On Nov. 1, 1937, Japanese government started to control dental materials, driving the campaigns for excluding foreign products and encourging the use of local products. In 1939, Nakajima dental manufacturers used this political and social atmosphere on their advertisement as saying "Our Nakajima's products have no compromise with the short raw materials, but only commitment to our quality". Since after 1940, the price and supply have been strongly under control, and the control group was appeared to manage all of supply and distribution of raw materials, regular price system, and specifications. At last, the Japanese national power were devastated in its production and distribution capacities, and get to the frustrated period. The main advertised dental devices and instruments in Korea during the Japanese colonized period were 1) dental chair, unit and cabinet, 2) dental x-ray, 3) compressors, 4) dental needles, 5) small instrument and carryon medical(emergency) kit, 6) oral hygiene and pyorrhea alveolaris, infrared rays, sunlight lamp, ultrashort wave treatment devices, 7)crown former, electric furnace, casting machine, articulator, electric lathe, and laboratory equipments, etc.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.330-337
• /
• 2002

The HANARO seismic monitoring system is classified as non-nuclear safety(NNS), seismic category I, and quality class T The seismic monitoring system installed at the instrument room consists of five field sensors and one monitoring cabinet. The field sensors are composed of three triaxial accelerometers which installed at base slab, free field and overhead crane support respectively, a seismic trigger and a seismic switch at base slab. The most parts of analog system except field sensors are not produced any more, the improvement of the system is to be needed. The analog system with magnetic tape recorder is not only out-of-date model but dependent upon foreign technology. So it is difficult to get the spare parts and the cost to buy them is increased. Therefore we have improved the analog seismic monitoring system into a new digital seismic monitoring analysis system(SMAS) except five field sensors. After the installation of the new SMAS, we have carried out the site acceptance test(SAT) to confirm the field functions. The results of SAT satisfy the requirements of the fabrication technical specification. This new SMAS is operating at HANARO instrument room to acquire and analyse the signal of earthquake.