• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3615-3620
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• 2013

Two novel copper(II) bromide complexes with pyridine containing Schiff base ligands, $Cu(pmed)Br_2$ and $Cu(pmed)Br_2$ where pmed = N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (pmed) and dpmed = N,N-diethyl-N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (dpmed) were synthesized and characterized using X-ray single crystal structure analysis, optical and magnetic susceptibility measurements. Crystal structural analysis of $Cu(pmed)Br_2$ showed that the copper(II) ion has a distorted square-pyramidal geometry with the trigonality index of ${\tau}=0.35$ and two intermolecular hydrogen bonds, which result in the formation of two dimensional networks in the ab plane. On the other hand, $Cu(pmed)Br_2$ displayed a near square-pyramidal geometry with the value of ${\tau}=0.06$. In both compounds, the NNN Schiff base and one Br atom occupy the basal plane, whereas the fifth apical position is occupied by the other Br atom at a greater Cu-Br apical distance. The reported complexes show $g_{\mid}$ > $g_{\perp}$ > 2.0023 with a $d_{x2-y2}$ ground state and a penta-coordinated square pyramidal geometry. Variable temperature magnetic susceptibility measurements showed that the developed copper(II) complexes follow the Curie-Weiss law, that is there are no magnetic interactions between the copper(II) ions since the Cu--Cu distance is too far for magnetic contact.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.314-323
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• 2010

Recently, granular soils having a large particle size are frequently used as a filling material in the construction of foundation, harbor, dam, and so on. The shear behavior of this granular soil plays a key role in the stability of structures. For example, soil particle crushing occurring at the interface between structure and soil and/or within soil mass can cause the disturbance of ground characteristics and consequently induce an issues in respect of stability of structures. In order to investigate the shear behavior according to an existence and nonexistence of particle crushing, numerical analyses were conducted by using the DEM(Discrete Element Method)-based software program PFC(Particle Flow Code). Using the crushing model and non-crushing model which were created in this study, numerical analyses of ring shear test were conducted and their results were analyzed and compared. In general, landslide and slope stability are accompanied by a large displacement and consequently not only a peak strength but also a residual strength are very important in the analysis of landslide and slope stability. However the direct shear test which has been commonly used in the determination of shear strength parameters has a limitation on displacement therefore the residual strength parameters can not be obtained. The characteristics of residual shear behavior were investigated through the numerical analyses in this study.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.18-26
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• 2004

The cost of underground work is a dominant factor to determine the total construction fee. It is generally 2 ${\~}$ 2.5 times higher than that of above ground for building with the same height. 'A new precast prestressed framing plan for underground parking building' was suggested with the beam of the least depth - U-type beams. The depth of regular rectangular reinforced concrete beam which is currently used in the underground parking of apartments could be reduced up to 12 ${\~}$ 34cm/story due to the development of a U-beams from the optimum process. Two full scale prototype U-beams were tested in this study. It was found that the Wide U-beams in the test showed higher strength than calculated nominal and design, however need to provide temporary supports to meet the flexural moment of construction load at the simply supported state before the lopping concrete hardens.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.457-464
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• 2005

In the case of tunneling, the equilibrium state of hydro-geologic environments destroy and change abruptly in some section of whole works. Specially, it's very possible for seawater to intrude toward the site of tunnel if the field is nearly located in a costal region. In this study, we have evaluated the mechanism related between groundwater flow and seawater intrusion that by impacts of tunneling. Various hydro-geological field tests have performed for getting four representative hydrogeologic properties of geologic formations such as transmissivity (T), storativity(S), longitudial dispersity(${\alpha}_L$), and effective porosity($n_e$). For the effect of tunneling, the numerical model was first simulated based on the governing equation of groundwater flow. The results showed that the maximum drawdown was 17.2m and the total inflow into the tunnel had the range from 0.48 to $3.63m^3/day/m$. Secondly, the three dimensional numerical model was analyzed to investigate a characteristic of seawater intrusion based on the previous simulated results of groundwater flow. The results showed the seawater moved as the range of $200{\sim}220m$ from the initial interface between seawater and groundwater toward the tunnel.

• Journal of the Korean Geotechnical Society
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• v.28 no.2
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• pp.23-31
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• 2012

The purpose of this study is to analyze earth pressure acting on a circular shaft-tunnel considering arching effect by centrifuge modeling test on sands. The centrifuge testing method provides a way to model an in-situ stress state condition with a stress gradient within a laboratory specimen. A small-scale model of circular shaft-tunnel, which has a real diameter of 6.0 m and height of 15.0 m, was designed and tested twice under 75g-level. Additionally, an effect of excavation was presented by separating two segments of circular shaft wall to find behavioral properties and strength of earth pressure along with excavating ground. The test results were compared with those of the proposed earth pressure equation. The test results showed that earth pressure decreased by about 70% in comparison with existing two-dimensional earth pressure. This fact might be attributed to three-dimensional arching effects.

• Journal of Radiation Protection and Research
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• v.38 no.2
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• pp.119-123
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• 2013

A simple laboratory-made radioactive source to check the integrity of a gamma spectrometry system with HPGe detector was developed. The check source consists of radium-riched soil which was ground in size of less than 0.154mm and contained in air tight cylinderical vial, and provides photons with 12 distinct energies. The spectra of the check source were measured once a month during one year, analyzed the charactreictics of their peaks. When the gamma spectrometry system was in normal state, the areas and FWHMs of the gamma rays with more than 3% gamma emission rate in radium and its decay products was constant within standard deviation 2% and 3%, respectively, except 77 keV peak. And it was found that this check source can play a sufficient role to check the integrity of a gamma spectrometry system using 10 peaks in the range of 77 to 2202 keV.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3567-3582
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• 2020

Human activities are often affected by weather conditions. Automatic weather recognition is meaningful to traffic alerting, driving assistance, and intelligent traffic. With the boost of deep learning and AI, deep convolutional neural networks (CNN) are utilized to identify weather situations. In this paper, a three-channel convolutional neural network (3C-CNN) model is proposed on the basis of ResNet50.The model extracts global weather features from the whole image through the ResNet50 branch, and extracts the sky and ground features from the top and bottom regions by two CNN5 branches. Then the global features and the local features are merged by the Concat function. Finally, the weather image is classified by Softmax classifier and the identification result is output. In addition, a medium-scale dataset containing 6,185 outdoor weather images named WeatherDataset-6 is established. 3C-CNN is used to train and test both on the Two-class Weather Images and WeatherDataset-6. The experimental results show that 3C-CNN achieves best on both datasets, with the average recognition accuracy up to 94.35% and 95.81% respectively, which is superior to other classic convolutional neural networks such as AlexNet, VGG16, and ResNet50. It is prospected that our method can also work well for images taken at night with further improvement.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.37-47
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• 2008

Design and construction of tunnels require understanding the influence of groundwater. Particularly, it is essential to know how the drainage conditions at the tunnel boundary affect flow behavior of ground adjacent to the tunnels. In this study flow behavior of a leaking tunnel was investigated using physical model tests for tunnel depths and various hydraulic boundary conditions. Particular concerns were given to flow lines toward tunnels. Test results showed that the boundary conditions hardly influence on flow patterns and time required to reach steady state conditions. It is revealed that with an increase in water depth, flow lines concentrated to the drain holes. The physical tests were numerically simulated. Numerical results showed that the flow behavior was represented appropriately by considering filter-drain hole drainage rather than boundary drainage all over the lining.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1263-1307
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• 2002

Pseudo-first-order rate constants (kobs) have been determined for the nucleophilic substitution reactions of p-nitrophenyl diphenyl phosphinate (PNPDPP) with substituted phenoxides (XC6H4O - ) and butane-2,3-dione monoximate (Ox- ) in 0.1 M borate buffer (pH = 10.0) at 25.0 ${\pm}0.1^{\circ}C$. The kobs value increases sharply upon addition of cethyltrimethylammonium bromide (CTAB) to the reaction medium up to near 7 ${\times}$ 10-4 M CTAB and then decreases smoothly upon further addition of CTAB. The rate enhancement upon the addition of CTAB is most significant for the reaction with -O2CC6H4O- and least significant for the one with C6H5O- , indicating that the reactivity of these aryloxides in the presence of CTAB cannot be determined by the basicity alone. The strength of the interaction of these anionic aryloxides with the positively charged micellar aggregates has been suggested to be an important factor to determine the reactivity in the presence of CTAB. The kobs value for the reaction with Ox- increases also upon the addition of CTAB. However, the increase in the kobs value is much more significant for the reaction with Ox- than for the one with ClC6H4O- , indicating that Ox- is less strongly solvated than ClC6H4O- in H2O. The ${\alpha}-effect$ shown by Ox- in H2O has been attributed to the ground-state solvation difference between Ox- and ClC6H4O- .

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.55-60
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• 2012

An free-fall object is received only force of gravity. Movement that only accept gravity is free-fall movement, and a free-falling object is free falling body. In other words, free falling body is only freely falling objects under the influence of gravity, regardless of the initial state of objects movement. In this paper, we assume, ignoring the resistance of the air, and the free-fall acceleration by the height does not change within the range of the short distance in the vertical direction. Under these assumptions, we can know about time and maximum height to reach the peak point from jumping vertically upward direction, time and speed of the car return to the starting position, and time and speed when the car fall to the ground. It can be measured by jumping degree and risk of accident from car or motorcycle in telematics.