• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.3
• /
• pp.407-417
• /
• 2011

Nowadays, the high land use, mainly used for urbanization, is affecting runoff loads of non-point pollutants to increase. According to this fact, increasing runoff loads seems like to appear that it contributes to high ratio of pollution loads in the whole the pollution loads and that this non-point source is the main cause of water becoming worse quality. Especially, concentrated pollutants on the impermeable roads run off to the public water bodies. Also the coefficient of runoff from roads is high with a fast velocity of runoff, which ends up with consequence that a lot of pollutants runoff happens when it is raining. Therefore it is very important project to evaluate the quantity of pollutant loads. In this study, I computed the pollutant loadings depending on time and rainfall to analyze characteristics of runoff while first flush storm water and evaluated the runoff time while first flush storm water and rainfall based on the change in curves on the graph. I also computed contribution ratio to identify its impact on water quality of stream. I realized that the management and treatment of first flush storm water effluents is very important for the management of road's non-point source pollutants because runoff loads of non-point source pollution are over the 80% of whole loads of stream. Also according to the evaluation of runoff loads of first flush storm water for SS, run off time was shown under the 30 minute and rainfall was shown under the 5mm which is less than 20% of whole rainfall. These are under 5mm which is regarded amount of first flush storm water by the Ministry of Environment and it is judged to be because run off by rainfall is very fast on impermeable roads. Also, run off time and rainfall of BOD is higher than SS. Therefore I realized that the management of non-point source should be managed and done differently depending on each material. Finally, the contribution ratio of pollutants loads by rainfall-runoff was shown SS 12.7%, BOD 12.7%, COD 15.9%, T-N 4.9%, T-P 8.9%, however, the pollutants loads flowing into the steam was shown 4.4%. This represents that the concentration of non-point pollutants is relatively higher and we should find the methodical management and should be concerned about non-point source for improvement on water quality of streams.

• Journal of Technologic Dentistry
• /
• v.33 no.4
• /
• pp.349-357
• /
• 2011

Purpose: In this study, for the reasons of observing the changes when using bonding agent with Ni-Cr alloy and Co-Cr alloy and using VM13 and Vintage MP ceramic which have the disparity in coefficient of thermal expansion, it is carried out to evaluate the characteristics of the bonding agent through the analysis of the interface between metal and ceramic and the analysis of bond strength by variable. Methods: The surface treatment was performed on the two kinds of alloy(Ni-Cr alloy and Co-Cr alloy) specimens, which were sandblasted and were treated with bonder application. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: As a result of observation of metal-ceramic interfacial properties, it was observed that Cr atoms were spread from the alloy body to the ceramic floor in the specimen of Group B. It was also seen that Cr, W atoms were spread from the alloy body to the ceramic floor in the specimen of Group S. In consequence of observing Shear bond strength, it was calculated that the specimen of BSV was 27.75(${\pm}11.21$)MPa, BSM was 27.02(${\pm}5.23$)MPa, BCV was 30.20(${\pm}5.99$)MPa, BCM was 27.94(${\pm}10.76$)MPa, SSV was 20.83(${\pm}2.58$)MPa, SSM was 23.98(${\pm}3.94$)MPa, SCV was 32.32(${\pm}4.68$)MPa, and SCM was 34.54(${\pm}10.63$)MPa. Conclusion: In the metal-ceramic interface of Bellabond plus sample group, diffusion of Cr atoms was incurred and diffusion of C Cr atoms and W atoms in the sample group of $Starloy{(R)}\;C$ was observed. Using bonding agent showed the higher bond strength than using the sand blasting treatment. In the Bellabond plus alloys, the specimen group with the use of binding materials showed higher shear bond strength, but didn't show statistically significant differences (p>0.05). In the $Starloy{(R)}\;C$ alloys, the specimen group with the use of binding materials showed higher shear bond strength and statistically significant differences(p<0.05). In terms of VM13 ceramic, it was in the Bellabond plus alloys that the high shear bond strength was showed, but there's no statistically significant differences(p>0.05). In terms of Vintage MP ceramic, it was in the $Starloy{(R)}\;C$ alloys that the high shear bond strength was showed and statistically significant differences(p<0.05). Metal-ceramic to fracture of the shear strength measurements and an analysis of all aspects of military usage fracture of the composite, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.4
• /
• pp.108-116
• /
• 2002

This paper presents the measurements and evaluation of voltage waveforms due to human electrostatic discharge(ESD). The principle of operation and design rule of a new device for measuring the ESD fast transient voltages with very fast rise time were described. Peak values and rise time of ESD voltages derived from a charged human body under a variety of experimental conditions were examined. The frequency bandwidth of the proposed voltage measuring system ranges from DC to 400[㎒]. The ESD voltage waveform is nearly equal to the ESD current waveform and the peak amplitude of ESD current waveform is roughly proportional to the ESD voltage in each experimental conditions. A rapid approach results in a discharge voltage with a faster initial rise time than for a slow approach. The voltages caused by direct finger ESDs have an initial slope with a relatively long, 10∼30[ns] rise time, but the amplitude is small. On the other hand, the voltages caused by direct hand/metal ESDs have a steep initial s1ope with 1 ∼3[ns] rise time, but an initial spike is very big. As a consequence, it was found that the ESD voltage and current waveforms strongly depend on the approach speed and material of intruder. These measurement results would be useful to design the ESD protective devices.

• Journal of Korea Water Resources Association
• /
• v.42 no.7
• /
• pp.547-558
• /
• 2009

General reliability assessment of levees embankment is performed with safety factors for rainfall characteristics and hydrologic and hydraulic parameters, based on the results of deterministic analysis. The safety factors are widely employed in the field of engineering handling model parameters and the diversity of material properties, but cannot explain every natural phenomenon. Uncertainty of flood analysis and related parameters by introducing stochastic method rather than deterministic scheme will be required to deal with extreme weather and unprecedented flood due to recent climate change. As a consequence, stochastic-method-based measures considering parameter uncertainty and related factors are being established. In this study, a variety of dimensionless cumulative rainfall curve for typhoon and monsoon season of July to September with generation method of stochastic temporal variation is generated by introducing Monte Carlo method and applied to the risk assessment of levee embankment using reliability index. The result of this study reflecting temporal and regional characteristics of a rainfall can be used for the establishment of flood defence measures, hydraulic structure design and analysis on a watershed.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.3
• /
• pp.377-382
• /
• 2000

Idiopathic CD4+ T-lymphocytopenia is defined as a depletion of CD4+ lymphocytes below $300/mm^3$ in the absence of HIV infection or other known causes of immunodeficiency. Many infectious diseases have been reported to be associated with idiopathic CD4+ T-lymphocytopenia, and there have also been a few cases of mycobacterial infection in idiopathic CD4+ T-lymphocytopenia. Until now, it has been unclear as to whether CD4+ T-lymphocytopenia is a predisposing factor for or a consequence of the mycobacterial infection. Pulmonary alveolar proteinosis is an uncommon disease characterized by the intraalveolar deposition of amorphous granular material that stains positive with PAS, and its association with mycobacterial infection has rarely been reported. Recently, we experienced a previously healthy young man who had been diagnosed as idiopathic CD4+ T-lymphocytopenia with disseminated mycobacterium kansasii infection and pulmonary alveolar proteinosis, and report this case.

• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.69-76
• /
• 2008

Three failure cases of CNG composite vessels were reported since after January 2005. The 1st and 2nd accidents were indebted to vessel defect and installation mistake. The 3rd was caused by gas leak at pipe connections. In this paper various aspects were studied based on information of the three failure analysis, which must be improved for better safety of the CNG bus system. Overpressure region caused by vessel explosion was theoretically predicted and also assessed by PHAST program. Explosion of 120 l vessel under 20 MPa is equivalent to 1.2 kg TNT explosion. The predicted value by PHAST was more serious than theoretical one. However, actual consequence of explosion was much less than both of the predicted consequences. Since the CNG vessel was designed by the performance based design methodology, it is difficult to verify whether the required process and tests were properly conducted or not after production. If material toughness is not enough, the vessel should be weak in brittle fracture at early in the morning of winter season since the metal temperature can be lower than the transition temperature. If autofrettage pressure is not correct, fatigue failure due to tensile stress during repeated charging is possible. One positive aspect is that fire did not ocurred after vessel failure. This may be indebted to fast diffusion of natural gas which hindered starting fire.

• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.38-41
• /
• 2008

In this research, we propose a new method for tracking the release rate using the concentration data obtained from the sensor. We used a sensor network that has already been set surrounding the area where hazardous gas releases can occur. From the real-time sensor data, we detected and analyzed releases of harmful materials and their concentrations. Based on the results, the release rate is estimated using the neural network. This model consists of 14 input variables (sensor data, material properties, process information, meteorological conditions) and one output (release rate). The dispersion model then performs the simulation of the expected dispersion consequence by combining the sensor data, GIS data and the diagnostic result of the source term. The result of this study will improve the safety-concerns of residents living next to storage facilities containing hazardous materials by providing the enhanced emergency response plan and monitoring system for toxic gas releases.

• The Korean Journal of Applied Statistics
• /
• v.20 no.3
• /
• pp.423-440
• /
• 2007

Although various models have been developed to establish the enterprise credit scoring, no model has utilized the enterprise human resource so far. The purpose of this study was to build an enterprise credit scoring model using enterprise human resource factors. The data to measure the enterprise credit score were made by the first-year research material of HCCP was used to investigate the enterprise human resource and 2004 Credit Rating Score generated from KIS-Credit Scoring Model. The independent variables were chosen among questionnaires of HCCP based on Mclagan(1989)'s HR wheel model, and the credit score of Korean Information Service was used for the dependent variables. The statistical method used for data analysis was logistic regression. As a result of constructing a model, 22 variables were selected. To see these specifically by each large area, 6 variables in human resource development(HRD) area, 15 in human resource management(HRM) area, and 1 in the other area were chosen. As a consequence of 10 fold cross validation, misclassification rate and G-mean were 30.81 and 68.27 respectively. Decile having the highest response rate was bigger than the one having the lowest response rate by 6.08 times, and had a tendency to decrease. Therefore, the result of study showed that the proposed model was appropriate to measure enterprise credit score using enterprise human resource variables.

• Journal of Korean Philosophical Society
• /
• v.126
• /
• pp.159-190
• /
• 2013

Feminist critics have criticized Aristotle as a sexist, misogynist, male chauvinist or masculinist, or, at least, their chief spokesman. Indeed, he says in the Politics that the male is by nature superior to the female and, also, that women possess the same deliberative part of the soul as men, but without authority, etc. In the Generation of Animals, he claims that the male supplies the form and the efficient cause, whereas the female supplies the material cause only in reproduction and describes the female as a mutilated being. When these remarks of Aristotle are read without considering their overall context, it hardly seems possible for him to escape from such severe criticism and condemnation. On the contrary, in what follows, I shall claim that the criticism and condemnation that has been ascribed to him is unfair. Although it is undeniable that Aristotle has made such remarks, it does not immediately follow that he was a sexist. In particular, I shall show his view on the status of men and women by analysing the value of matter and form ascribed in two of his main philosophical theories, the theories of hylomorphism and four causes. In consequence, we shall arrive at the conclusion that, since the theories do not imply the significance or necessity of either form or matter alone, but of both, there is no sign of sexism or misogyny or male chauvinism in Aristotle.

• Korean Journal of Heritage: History & Science
• /
• v.50 no.2
• /
• pp.40-61
• /
• 2017

This study investigated material characteristics of composition and variable strength measurement using physicochemical and petrographic analysis for lime-soil mixture barrier tombs of Guri Galmae site in Joseon Dynasty. The tomb barriers are composed mainly of microcrystalline calcite, quartz, feldspar and mica with lime matrix. The lime matrix shows compact sheet texture, and some samples show hydration aggregates with needle-shaped textures. Gypsum occurred as a secondary process where carbonization reactions were poor. Concentrations of CaO in the tomb barrier very widely ranged from 4.43 to 36.19 wt.%, specific gravity and absorption ratio of the materials show of 1.35 to 1.62 and 20.1 to 32.6%, respectively. As the rebound hardness, the materials ranged from 10.0 to 28.4 (mean 15.7). The values are higher in the $-90^{\circ}$ direction rather than in the $0^{\circ}$ direction with the consequence that the values indicate more strength toward the vertical direction. Difference in strength by directions was caused by the directions of the tomb barriers, which is related to the processes in each stage. In the tomb barriers, ultrasonic velocity and unconfined compressive strength ranged from 1,049.2 to 1,728.9m/s and under 5.00MPa, respectively. Variation patterns between the two are very similar in values. As the result of composition and strength, the materials of higher contents on CaO are higher in strength values. Generally, techniques and skills to make the lime-soil mixture barriers are interpreted as low qualities in relatively.