• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.156-172
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• 2014

This research measures and compares on-site net radiation energy, air temperature, wind speed, and surface temperature considering various spatial characteristics with a focus on land use types in urban areas in Changwon, Southern Gyeongsangnam-do, to analyze the accuracy of an ENVI-met model, which is an analysis program of microclimate. The on-site measurement was performed for three days in a mobile measurement: two days during the daytime and one day during the nighttime. The analysis using the ENVI-met model was also performed in the same time zone as the on-site measurement. The results indicated that the ENVI-met model showed higher net radiation than the on-site measurement by approximately $300Wm^{-2}$ during the daytime whereas the latter showed higher net radiation energy by approximately $200Wm^{-2}$ during the nighttime. The temperature was found to be much higher by approximately $2-6^{\circ}C$ in the on-site measurement during both the daytime and nighttime. The on-site measurement also showed higher surface temperature than the ENVI-met by approximately $7-13^{\circ}C$. In terms of the wind speed, there was a significant difference between the results of the ENVI-met model and on-site measurement. As for the correlation between the results of the ENVI-met model and on-site measurement, the temperature showed significantly high correlation whereas the correlations for the net radiation energy, surface temperature, and wind speed were very low. These results appear to be affected by excessive or under estimation of solar and terrestrial radiation and climatic conditions of the surrounding areas and characteristics of land cover. Hence, these factors should be considered when applying these findings in urban and environment planning for improving the microclimate in urban areas.

• Tunnel and Underground Space
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• v.30 no.4
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• pp.382-393
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• 2020

The engineered barrier system of high-level radioactive waste disposal must maintain its performance in the long term, because it must play a role in slowing the rate of leakage to the surrounding rock mass even if a radionuclide leak occurs from the canister. In particular, it is very important to clarify gas dilation flow phenomenon clearly, that occurs only in a medium containing a large amount of clay material such as a bentonite buffer, which can affect the long-term performance of the bentonite buffer. Accordingly, DECOVALEX-2019 Task A was conducted to identify the hydraulic-mechanical mechanism for the dilation flow, and to develop and verify a new numerical analysis technique for quantitative evaluation of gas migration phenomena. In this study, based on the conventional two-phase flow and mechanical behavior with effective stresses in the porous medium, the hydraulic-mechanical model was developed considering the concept of damage to simulate the formation of micro-cracks and expansion of the medium and the corresponding change in the hydraulic properties. Model verification and validation were conducted through comparison with the results of 1D and 3D gas injection tests. As a result of the numerical analysis, it was possible to model the sudden increase in pore water pressure, stress, gas inflow and outflow rate due to the dilation flow induced by gas pressure, however, the influence of the hydraulic-mechanical interaction was underestimated. Nevertheless, this study can provide a preliminary model for the dilation flow and a basis for developing an advanced model. It is believed that it can be used not only for analyzing data from laboratory and field tests, but also for long-term performance evaluation of the high-level radioactive waste disposal system.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.200-210
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• 2015

The modeling for fast pyrolysis of biomass in fluidized bed reactor has been developed for accurate prediction of bio-oil and gas products and for yield improvement. The purpose of this study is to analyze and to compare the CFD(Computational Fluid Dynamics) simulation results with the experimental data from the CFD simulation results with the experimental data from the reference(Mellin et al., 2014) for gas products generated during fast pyrolysis of biomass in fluidized bed reactor. CFD(ANSYS FLUENT v.15.0) was used for the simulation. Complex pyrolysis reaction scheme of biomass subcomponents was applied for the simulation of pyrolysis reaction. This pyrolysis reaction scheme was included reaction of cellulose, hemicellulose, lignin in detail, gas products obtained from pyrolysis were mainly $CO_2$, CO, $CH_4$, $H_2$, $C_2H_4$. The deviation between the simulation results from this study and experimental data from the reference was calculated about 3.7%p, 4.6%p, 3.9%p for $CH_4$, $H_2$, $C_2H_4$ respectively, whereas 9.6%p and 6.7%p for $CO_2$ and CO which are relatively high. Through this study, it is possible to predict gas products accurately by using CFD simulation approach. Moreover, this modeling approach should be developed to predict fluidized bed reactor performance and other gas product yields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.542-552
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• 2018

In this paper, the precast method of a concrete eco-pillar debris barrier was proposed to improve the construct ability and economic efficiency. The performance was validated by experimental and structural analysis. The steel debris barrier has a high construction cost and causes environmental damage with corrosion. The construction of a concrete eco-pillar debris barrier has been increased recently. On the other hand, there are no design standards regarding debris barriers in Korea, and debris barriers are being designed by the experience and sense of engineers. Therefore, in this study, a method to determine the design external forces was proposed and the design was performed by applying a hollow cross-section to the debris barrier. In addition, three types of connection methods of a concrete cantilever column with the maximum bending moment acts were proposed, and validation of the performance of each type was performed with a real-scale experiment. The experimental results showed that the type with loop reinforcement had the highest rigidity and the type with anchorage performance exceeded the maximum bending moment according to the ultimate load. In the manufacturing procedure of mock-up debris barriers, the type with an anchorage-bar was found to have superior construct ability.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.193-206
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• 2018

In this study, as part of the "Small-scale $CO_2$ Injection-Demonstration Project in Offshore Pohang Basin", we performed drilling and completion of a $CO_2$ injection well from the offshore platform installed in the Yeongil Bay, Pohang city, Gyeongsang buk-do. The drilling of injection well was carried out from an offshore platform installing on the sediment formations of the Pohang Basin. Drilling diameters were reduced by stages, depending on the formation pressure and groundwater pressure along a depth and the casing installation and cement grouting in drilled hole were performed at each stage. The injection well was drilled to a final depth of 816.5 m with a hole diameter of 4 7/8 inches (${\Phi}124mm$) and the perforated casing for an injection section was installed in a depth of 746.5~816.5 m. Injection tubing, packer, and christmas tree were installed for the completion of an injection well for $CO_2$. The validation project of the $CO_2$ injection was accomplished successfully by drilling the injection well and installing the injection facilities, and through the suitable $CO_2$ injection process. The current injection facility is a facility for small-scale injection demonstration of 100 tons. In the case of large-scale demonstration facility test of a capacity of 10,000 tons, research is underway through the upgrading of the injection facilities.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.444-451
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• 2016

Most research on membrane fouling models in the past are based on theoretical equations in lab-scale experiments. But these studies are barely suitable for applying on the full-scale spot where there is a sequential process such as filtration, backwash and drain. This study was conducted in submerged membrane system which being on operation auto sequentially and treating wastewater from G-water purification plant in Incheon. TMP had been designated as a fouling indicator in constant flux conditions. Total volume of inflow and SS concentration are independent variables as major operation parameters and time-series analysis and prediction of TMP were conducted. And similarity between simulated values and measured values was assessed. Final prediction model by using genetic algorithm was fully adaptable because simulated values expressed pulse-shape periodicity and increasing trend according to time at the same time. As results of twice validation, correlation coefficients between simulated and measured data were $r^2=0.721$, $r^2=0.928$, respectively. Although this study was conducted limited to data for summer season, the more amount of data, better reliability for prediction model can be obtained. If simulator for short range forecast can be developed and applied, TMP prediction technique will be a great help to energy efficient operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.111-116
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• 2018

This research examines the drop impact of an external cooling unit package of an air conditioner system. The packaging is composed of a shock-absorbing material, which protects the package contents by absorbing the impact energy and other parts for fixture. Accurate quantification of the impact acceleration experienced by the package contents is necessary to design an effective packaging with minimal volume and sufficient shock absorbing capacity. Explicit time integration was used for the drop impact analyses. A finite element model of the package was constructed, material testing and material model selection were carried out, and sensors for data acquisition were modeled to obtain accurate simulation results. The results were compared with real physical test data. Due to imprecise modeling of the damping, the acceleration and strain values predicted by the simulation were larger than those from physical test. However, the trend of the history data and the peak deceleration value in the direction of impact showed good agreements. Thus, the analysis model and scheme are suitable for the design of an air conditioner cooling unit package.

• Journal of Korean Academy of Nursing Administration
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• v.6 no.3
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• pp.357-374
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• 2000

The purpose of this study was to validate knowledge outcomes included Nursing Outcomes Classification(NOC) developed by Johnson and Maas at the University of Iowa. A sample of 71 nurse experts working in university affiliated hospitals participated in this study. They were asked to rate indicators that examplified the outcomes on a scale of 1(indicator is not all characteristic) to 5(indicator is very characteristic). A questionnaire with an adaptation of Fehring's methodology was used to establish the content validity of outcomes. The results were as follow: 1. All indicators were considered to be 'supporting' and no indicators were considered to be 'nonsupporting'. 2. 'Knowledge: Treatment Regimen' attained and OCV score of 0.816 and was the highest OCV score among outcomes. 3. 'Knowledge: Energy Conservation' attained an OCV score of 0.748 and was the lowest OCV score among abuse outcomes. 4. 'Knowledge: Breastfeeding' attained an OCV score of 0.790 and was the highest indicator was 'description of benefits of breastfeeding'. 5. 'Knowledge: Child Safety' attained an OCV score of 0.778 and was the highest indicator was 'demonstration of first aids techniques'. 6. 'Knowledge: Diet' attained an OCV score of 0.779 and was the highest indicator was 'performance of self-monitoring activities'. 7. 'Knowledge: Disease Process' attained an OCV score of 0.815 and was the highest indicator was 'description of signs and symptoms'. 8. 'Knowledge: Health Behaviors' attained an OCV score of 0.800 and was the highest indicator was 'description of safe use of prescription drugs'. 9. 'Knowledge: Health Resources' attained an OCV score of 0.794 and was the highest indicator was 'description of need for follow-up care'. 10. 'Knowledge: Infection Control' attained an OCV score of 0.793 and was the highest indicator was 'description of signs and symptoms'. 11. 'Knowledge: Medication' attained an OCV score of 0.789 and was the highest indicator was 'description of correct administration of medication'. 12. 'Knowledge: Personal Safety' attained an OCV score of 0.804 and was the highest indicator was 'description of measures to reduce risk of accidental injury'. 13. 'Knowledge: Prescribed Activity' attained an OCV score of 0.810 and was the highest indicator was 'proper performance of exercise'. 14. 'Knowledge: Substance Use Control' attained an OCV score of 0.809 and was the highest indicator was 'description of signs of dependence during substance withdrawl'. 15. 'Knowledge: Treatment Procedure(s)' attained an OCV score of 0.795 and was the highest indicator was 'description of appropriate action for complications'. 16. 'Knowledge: Treatment Regimen' attained an OCV score of 0.816 and was the highest indicator was 'description of self-care responsibilities for emergency situations'. More outcomes need to be validated and outcomes sensitive to Korean culture need to be developed.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.233-247
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• 2008

Process monitoring technology is able to detect the faults and the process changes which occur in a process unpredictably, which makes it possible to find the reasons of the faults and get rid of them, resulting in a stable process operation, high-quality product. Statistical process monitoring method based on data set has a main merit to be a tool which can easily supervise a process with the statistics and can be used in the analysis of process data if a high quality of data is given. Because a real process has the inherent characteristics of nonlinearity, non-Gaussianity, multiple operation modes, sensor faults and process changes, however, the conventional multivariate statistical process monitoring method results in inefficient results, the degradation of the supervision performances, or often unreliable monitoring results. Because the conventional methods are not easy to properly supervise the process due to their disadvantages, several advanced monitoring methods are developed recently. This review introduces the theories and application results of several remarkable monitoring methods, which are a nonlinear monitoring with kernel principle component analysis (KPCA), an adaptive model for process change, a mixture model for multiple operation modes and a sensor fault detection and reconstruction, in order to tackle the weak points of the conventional methods.

• Clinical and Experimental Pediatrics
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• v.60 no.7
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• pp.227-231
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• 2017

Purpose: This study aimed to verify the safety of low-dose topiramate on language development in pediatric patients with migraine. Methods: Thirty newly diagnosed pediatric patients with migraine who needed topiramate were enrolled and assessed twice with standard language tests, including the Test of Language Problem Solving Abilities (TOPs), Receptive and Expressive Vocabulary Test, Urimal Test of Articulation and Phonology, and computerized speech laboratory analysis. Data were collected before treatment, and topiramate as monotherapy was sustained for at least 3 months. The mean follow-up period was $4.3{\pm}2.7months$. The mean topiramate dosage was 0.9 mg/kg/day. Results: The patient's mean age was $144.1{\pm}42.3months$ (male-to-female ratio, 9:21). The values of all the language parameters of the TOPs were not changed significantly after the topiramate treatment as follows: Determine cause, from $15.0{\pm}4.4$ to $15.4{\pm}4.8$ (P>0.05); making inference, from $17.6{\pm}5.6$ to $17.5{\pm}6.6$ (P>0.05); predicting, from $11.5{\pm}4.5$ to $12.3{\pm}4.0$ (P>0.05); and total TOPs score, from $44.1{\pm}13.4$ to $45.3{\pm}13.6$ (P>0.05). The total mean length of utterance in words during the test decreased from $44.1{\pm}13.4$ to $45.3{\pm}13.6$ (P<0.05). The Receptive and Expressive Vocabulary Test results decreased from $97.7{\pm}22.1$ to $96.3{\pm}19.9months$, and from $81.8{\pm}23.4$ to $82.3{\pm}25.4months$, respectively (P>0.05). In the articulation and phonology validation in both groups, speech pitch and energy were not significant, and all the vowel test results showed no other significant values. Conclusion: No significant difference was found in the language-speaking ability between the patients; however, the number of vocabularies used decreased. Therefore, topiramate should be used cautiously for children with migraine.