• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1211-1214
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• 2003

The anomalies that appear at every multiple of 15 ℃ in the viscosity of a thin liquid film of water and of water near solid interfaces are explained in this paper by comparing the thermal wavelength and molecular free volume of water, and quantum numbers are found. The possibility that these anomalies are related to the preferred and/or lethal temperatures of organisms is considered. The toxicity of heavy water (D₂O) can also be explained with this approach.

• Bulletin of the Korean Chemical Society
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• v.5 no.2
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• pp.82-86
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• 1984

The anomalous behaviors of supercooled water are explained by using a two-solid-like structure model in which an equilibrium is assumed between open structures and closed structures. Besides these structures, small fraction of monomer exists in liquid water. The anomalies of liquid water are classified into two groups: structural and energetic. The structural anomalies appear in enlarged fashions in a supercooled state where the free volume is small.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.6
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• pp.351-360
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• 1988

Based on historic data of monthly means of sea surface temperatures (SST) for 24 years $(1921\~1944) $ at 23 Korean and Japanese coastal stations in the East Sea (the Japan Sea), we analyzed spatio-temporal characteristics of coastal SST and SST anomalies. The means of SST at Korean coast are higher than those at Japanese coast of the same latitudes, and the annual range of SST at Korean coast are larger than those at Japanese coast. Empirical orthogonal function analysis shows that almost all $(96\%)$ of the SST fluctuations are described by simultaneous seasonal variations. The flurtuations of SST anomalies are small in the Korea Strait and large at the boundaries between the warm and told currents in the basin. The fluctuations of SST anomalies along Korean coast are correlated each other The same is true for SST anomalies along Japanese coast. However, there is only weak correlation between the SST anomalies at Korean coast and those at Japanese coast. Empirical orthogonal function analysis shows that $27\%$ of the coastal SST anomalies in the East Sea are described by simultaneous fluctuations, and $12\%$ of them are described by alternating fluctuations between Korean and Japanese coasts.

• Structural Engineering and Mechanics
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• v.84 no.2
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• pp.181-206
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• 2022

This paper presents experimental modal analysis and static load testing results to validate the accuracy of dynamic parameters-based damage locating indices in RC structures. The study investigates the accuracy of different dynamic-based damage locating indices compared to observed crack patterns from static load tests and how different damage levels and scenarios impact them. The damage locating indices based on mode shape curvature and mode shape fourth derivate in their original forms were found to show anomalies along the beam length and at the supports. The modified forms of these indices show higher sensitivity in locating single and multi-cracks at different damage scenarios. The proposed stiffness reduction index shows good sensitivity in detecting single and multi-cracks. The proposed anomalies elimination procedure helps to remove the anomalies along the beam length. Also, the adoption of the proposed weighting method averaging procedure and normalization procedure help to draw the overall crack pattern based on the adopted set of modes.

• Journal of Korean Society on Water Environment
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• v.40 no.4
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• pp.168-178
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• 2024

Wastewater treatment plants are constantly exposed to influent wastewater that is constantly changing. This poses a major challenge to the operation of the plants. It is crucial to have a rapid and accurate measurement of the influent concentrations of wastewater in order to maintain and optimize treatment performance, as well as to develop energy-saving strategies. While laboratory measurements provide the highest accuracy in determining influent water quality, they are inevitably time-consuming procedures. In order to cope with the ongoing disturbances from wastewater influent, absorption-based optical measuring instruments have been developed. These instruments can detect the influent water quality in a short amount of time, improving their practicality and reliability. However, when these optical measuring instruments malfunction, the accuracy of the measured values decreases, leading to unreasonable operation of the treatment plant. This paper proposes a method for detecting anomalies in optical water quality measurement devices. The Harmony Search algorithm is used to validate the measured water quality values and detect abnormalities such as contamination or physical anomalies in the measurement apparatus. To assess the performance of the developed algorithm in detecting anomalies, validation was conducted by installing it in a field-scale wastewater treatment plant. The results consistently showed that the developed fault detection method for optical water quality measurements equipment provided acceptable results for normal, temporary abnormal, and long-term abnormal conditions.

• 한국해양학회지
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• v.22 no.2
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• pp.57-62
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• 1987

The Markov chain properties of the sea surface temperature (SST) anomalies, namely, the dependency of the monthly SST anomaly on that of the previous month, are studied based on the SST data for 28years(1957-1984) at 5 stations in the southeastern coast of Korea. Wi classified the monthly SST anomalies at each station into the low, the normal and the high state, and computed transition probabilities between SST anomalies of two successive months The standard deviation of SST anomalies at each station is used as a reference for the classification of SST anomalies into 3states. The transition probability of the normal state to remain in the same state is about 0.8. The transition probability of the high or the low states to remain in the same state is about one half. The SST anomalies have almost no probability to transit from the high (the low) state to the low (the high) state. Statistical tests show that the Markov chain properties of SST anomalies are stationary in tine and homogeneous in space. The multi-step Markov chain analysis shows that the 'memory' of the SST anomalies at the coastal stations remains about 3 months.

• Ocean and Polar Research
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• v.23 no.2
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• pp.189-194
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• 2001

A practical algorithm for prediction of the sea surface temperatures (SST)from the satellite remote sensing data is presented in this paper. The fluctuations of SST consist of deterministic normals and stochastic anomalies. Due to large thermal inertia of sea water, the SST anomalies can be modelled by autoregressive or Markov process, and its near future values can be predicted provided the recent values of SST are available. The actual SST is predicted by superposing the pre-known SST normals and the predicted SST anomalies. We applied this prediction algorithm to the NOAA AVHRR weekly SST data for 18 years (1981-1998) in the seas adjacent to Korea (115-$145^{\circ}E$, 20-$55^{\circ}N$). The algorithm is applicable not only for prediction of SST in near future but also for nowcast of SST in the cloud covered regions.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.645-652
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• 1999

In order to simulate and investigate the major characteristics of El Nino/Southern Oscillation(ENSO) and Madden Jullian Oscillation(MJO), an intermediate type atmosphere-ocean coupled model is developed and their results are examined. The atmosphere model is a time-dependent non-linear perturbation moist model which can determine the internal heating for itself. The counterpart of the atmosphere model is GCM-type tropical ocean model which has fine horizontal and vertical grid resolutions. In the coupled experiment, warm SST anomaly and increased precipitation and eastward wind and current anomalies associated with ENSO and MJO are properly simulated in Pacific and Indian Oceans. In spite of some discrepancies in simulation MJO, the observed atmospheric and oceanic low-frequency characteristics in the tropics are successfully identified. Among them, positive SST anomalies centered at the 100m-depth of tropical eastern-central Pacific due to the eastward advection of warm water and reduced equatorial upwelling, and negative anomalies in the Indian and western Pacific seem to be the fundamental features of tropical low-frequency oscillations.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.165-168
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• 2010

This paper describes the results of complete Bouguer anomalies computed from the Free-air anomalies that derived from Sandwell and DNSC08 mairne gravity models. Complete bouguer corrections consist of three parts: the bouguer correction (Bullard A), the curvature correction (Bullard B) and the terrain correction (Bullard C). These all corrections have been computed over the East Sea on a $1'{\times}1'$ elevation data (topography and bathymetry) derived from ETOPO1 global relief model. In addition, a constant topographic (sea-water) density of $2,670kg/m^3$ ($1,030kg/m^3$) has been used for all correction terms. The distribution of complete bouguer anomalies computed from DNSC08 are -34.390 ~ 267.925 mGal, and those from Sandwell are -32.446 ~ 266.967 mGal in East Sea. The mean and RMSE value of the difference between DNSC08 and Sandwell is $0.036{\pm}2.373$ mGal. The highest value of complete bouguer anomaly are found around the region of $42{\sim}43^{\circ}N$ and $137{\sim}139^{\circ}E$ (has the lowest bathymetry) in both models. Theses values show that the gravity distribution of both models, DNSC08 and Sandwell, are very similar. They indicate that satellite-based marine gravity model can be effectively used to analyze the geophysical, geological and geodetic characteristics in East Sea.

• Proceedings of the KSRS Conference
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• v.1
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• pp.328-331
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• 2006

Eight years of SeaWiFS data quantify variability in the time/space patterns of spring bloom development in the Gulf of Maine (GOM). Maximum and earliest spring bloom are usually observed over Georges Bank, later on the deep basins from the west to the east GOM, and latest development along the eastern Maine coast in cold, tidally mixed water. Pronounced interannual variability of spring bloom timing, spatial position, and magnitude are shown in the GOM. Strongest negative anomalies are present in April 1998 and 2001 over Georges Bank and the eastern GOM, and in January to April of 2005 over the most of GOM. Positive anomalies are strong in April 2001, 2003 and 2004 in varying locations as well as in February and March 1999. It is suggested that interannaul variability in spring phytoplankton bloom concentrations is strongly associated with changes in water mass and stratification which might be influenced by basin-scale forcing due to large climate change.