• Earthquakes and Structures
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• v.1 no.4
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• pp.327-344
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• 2010

This paper summarizes results of a comprehensive analytical study aimed at evaluating the influence of strong ground motion duration on residual displacement demands of single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) systems. For that purpose, two sets of 20 earthquake ground motions representative of short-duration and long-duration records were considered in this investigation. While the influence of strong ground motion duration was evaluated through constant-strength residual displacement ratios, $C_r$, computed from the nonlinear response of elastoplastic SDOF systems, its effect on the amplitude and height-wise distribution of residual drift demands in MDOF systems was studied from the response of three one-bay two-dimensional generic frame models. In this investigation, an inelastic ground motion intensity measure was employed to scale each record, which allowed reducing the record-to-record variability in the estimation of residual drift demands. From the results obtained in this study, it was found that long strong-motion duration records might trigger larger median $C_r$ ratios for SDOF systems having short-to-medium period of vibration than short strong-motion duration records. However, taking into account the large record-to-record variability of $C_r$, it was found that strong motion duration might not be statistically significant for most of the combinations of period of vibration and levels of lateral strength considered in this study. In addition, strong motion duration does not have a significant influence on the amplitude of peak residual drift demands in MDOF systems, but records having long strong-motion duration tend to increase residual drift demands in the upper stories of long-period generic frames.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.293-305
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• 2023

Three ground models are analyzed using a 1g shaking table and laminar shear box (LSB) to investigate the impact of the ground structure on seismic wave amplification during earthquakes. Multi-layer horizontal, embankment, and basin ground models are selected for this investigation, with each model being divided into dense and loose ground layers, Accelerometers are installed during the construction of each ground model to capture any seismic wave amplification owing th the propagation of an artificial seismic wave, sine wave sweep, and 10-Hz sine wave through a given ground model. The amplification of the tested seismic waves is analyzed using the observed peak ground acceleration and spectrum acceleration. The observed acceleration amplification in the multi-layer horizontal ground model is significantly higher the seismic waves that propagated across the dense ground-loose ground boundary compared with those that only propagated through the dense ground. Furthermore, the observed acceleration amplification gradually increases in the central part of the multi-layer embankment and basin models for the seismic waves that propagated across the dense ground-loose ground boundary.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.5
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• pp.267-272
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• 2009

This study aims to investigate and analyze the present state of ground source heat pump(GSHP) system applied in Korea. It is based on the statistic from the New and Renewable Energy Center in Korea and construction results of the professional companies registered to the center. The research items were installed area, installed year, building use, ground heat exchange type and heat exchanger type of the pump. According to the result of investigation, the using GSHP system have been increasing steadily as the space heating and cooling system in a building. The capacity of this system is also becoming lager based on technical and economical feasibility analysis about the system since GSHP system first introduced in 2000.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.696-699
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• 2004

A side scan sonar system uses the towfish installed sonars, It is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. It used to fined objects and investigate on the seabed surface. But, recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. So, it needs various filtering technique and image processing techniques development to acquire high resolution image. therefore, this research develops a side scan sonar using multi-beam sensors that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.317-318
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• 2006

The towfish oi a side scan sonar is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. It used to find objects and Investigate on the seabed surface. But, recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. So, it needs various filtering technique and image processing techniques development to acquire high resolution image. Therefore, this research develops a side scan sonar using multi-beam sensors that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• Journal of Pharmaceutical Investigation
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• v.17 no.4
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• pp.175-181
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• 1987

To increase the dissolution rate of furosemide, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of furosemide with chitin or chitosan were prepared by grinding in a ball mill. The ground mixture showed a faster and more enhanced dissolution rate than the physical mixture or intact furosemide. The crystalline peaks of furosemide disappeared in the ground mixtures indicating the production of amorphous form. The comparison of infrared spectra of the physical mixture and the ground mixture showed an interaction such as association between the functional groups of furosemide and chitin or chitosan in the molecular level. The weight losses in TGA curves showed all the same patterns. However, the endothermic peak due to the fusion of furosemide in DTA curve disappeared in the ground mixture indicating the different thermal property. The dissolution of furosemide from ground mixtures was fast in the order of chitosan and then chitin. The co-grinding technique with chitin or chitosan provided a promising way enhancing the dissolution rate of practically insoluble drug.

• Tunnel and Underground Space
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• v.27 no.6
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• pp.377-386
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• 2017

This study was carried out to predict the future technology on the prevention and reclamation of mining induced subsidences in Korea. We summarized the technical improvement of ground surveys and investigation, ground stability assessment, ground reinforcement, ground monitoring system and so on. It is essential to improve the technology that we try to collect and review all the data that is implemented on the site of mined area in Korea and collaborate all the members of public and private business sectors. We, also, try to expand our business area to related industry such as tunnelling, civil infrastructure, underground environmental assessment etc, and continue to develop oversea's market.

• The Journal of Fisheries Business Administration
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• v.38 no.1 s.73
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• pp.97-113
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• 2007

This study attempts to suggest a new approach of the the determination of location and range of fishing ground in the coastal vessel fishery using the anaiysis of variance(ANOVA) and least significant difference test(LSD test) in statistics. The important result of the empirical study is that there is no significant difference in fisfishing ground based on between fishermen's argument and spot investigation. But there is stastitically significant difference in fisfishing ground based on between fishermen's argument and the official documents of fishing records for past three years. The results suggest us that there exists a possibility of misuse of tax free oil providied for subsidizing fisheries. But because of the range limitation of data, it is impossible for us to generalize the above results.

• Water for future
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• v.12 no.1
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• pp.21-27
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• 1979

Ground water stored in the alluvium and the rocks provides the vase flow of the streams and can be withdraw from wells and infiltration galleries. And it is also recharge naturallyby precipitation. The amount of ground water in the four major basins it is estimated to be about 137,000 million cubiv meters(Table1), while nationwide ground water storage to be about 232,000 million cubic meters. The estimation of storage volume has been made on the basis of assumed thickness of the saturated zone of the different rocks and assumed porosities of those rocks. The values of the porosity of alluvium and saprolite were assumed to be 25% and 40% respectivvely which are based on tests made of similar materials in Georgia, U.S. The volume of water in storage is believed to be a conservative estimate. Detailed geologic and hydrologic investigation should be made where and when water resources are needed.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.346-350
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• 1994

This investigation was undertaken for the purpose of studying the effect of the addition of the powder(0, 1, 2, 3%)from fruit of paper mulberry(Broussonetia Kazinoki SieboId) on the hardness, cohesiveness, elasticity, gumminess, chewiness, cooking loss and sensory characteristics of cooked ground beef with or without soysauce. The results obtained were summerized as follows; Hardness, gumminess, chewiness, and cooking loss were decreased by increasing the percent of adding the powder from the fruit of paper mulberry. As a result of sensory evaluation for cooked ground beef, sample with powder from the fruit of paper mulberry showed the higher scores in most of the characteristics. And cooked ground beef added the powder from the fruit of paper mulberry with soysauce showed the higher decreasing rate of hardness than those of without soysauce.