• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.76-83
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• 2021

This study examines the bending behavior of lap-spliced ultra-high-strength fiber-reinforced concrete members and evaluates the safety of the design codes for ultra-high-strength fiber-reinforced concrete structures. An experiment on a total of six beams was performed. The main variables were the fiber-inclusion and the lap-spliced length at the center of the beams. The steel fibers in a volume fraction of 2% were used, and the lap-splice lengths were determined to be 8db and 16db. As a result of the test, the specimens not reinforced with fiber lost abrupt load-bearing capacity at the lap region and did not experience yielding of the reinforcing bar. In the case of fiber-reinforced concrete, if a lap-splice length of 16db is secured, the yielding of the main reinforcing bar can be experienced, and appropriate flexural strength can be expressed. Based on the experimental results of this study, as a result of reviewing the lap-splice length calculation formulas of the current design standards and the ultra-high-strength concrete structural design recommendations, it was found that all of them were evaluated conservatively.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.3
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• pp.116-135
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• 2019

Objectives : The purpose of this study is to analyze how purpura and vasculitis have been treated with Korean medicine and potentially to present with future direction of research and treatment. Methods : We searched clinical studies from the Korean databases including Oriental medicine Advanced Searching Integrated System(OASIS), Korean Traditional Knowledge Portal(KTKP), National Discovery for Science Leader(NDSL), Research Information Sharing Service(RISS), using keywords related to "Purpura" and "Vasculitis" from January 2000 to May 2019. Results : A total of 20 studies were selected for analysis. More than half of the patients provided with detailed information were under 19 year-olds, and upper respiratory infection, stress and fatigue, seasonal factor were among the most frequently stated as predisposing factors. Among many treatment modalities, herbal medicine was the most frequently used, followed by acupuncture and herbal acupuncture. 23 basic herbal medicine formulas were retrieved from 20 articles, most frequently used being Guibi-tang(歸脾湯加味), Samul-tang(四物湯加味) and Yukmijihwang-tang(六味地黃湯加味). In total, 122 Korean medicine herbs were used, most frequently used herbs being Glycyrrhizae Radix et Rhizoma(甘草), Angelicae Gigantis Radix(當歸), Poria Sclerotium(茯?) and Paeoniae Radix(芍藥). By its category, herbs were mostly classified into Tonyfying and replenishing medicinal(補益藥), Heat-clearing medicinal(淸熱藥) and Exterior-releasing medicinal(解表藥). Patients with total treatment period of 3 months or under were 2/3 of all cases provided with detailed information. Follow up periods were short in general with only 6 cases of over 6 months. The primary motive of patients to receive Korean medicine treatments was unresponsiveness or adverse effects of western medication. Conclusion : Through this literature review, we could find out tendencies of Korean medicine treatments of purpura and vasculitis up to date and some points that may have clinical significance.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.187-194
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• 2019

Intake ratio from river constitutes about 31% (8/26) that beings to "water stress country" as "Medium ~ High" with China, India, Italy, South Africa, etc. Therefore, the present study on a dam that is the most effective and direct for securing water resources has been performed. First of all, climate change scenarios were investigated and analyzed. RCP 4.5 and 8.5 with 12.5 km grid resolution presented in the IPCC (Intergovernmental Panel on Climate Change) 5th Assessment Report (AR5) were applied to study watershed using SWAT (Soil and Water Assessment Tool) and HEC-ResSim models that carried out co-operation. Based on the results of dam simulation, the reduction effects of floods and droughts were quantitatively presented. The procedures of dam projects of the USA, Japan and Korea were investigated. As a result, there are no estimating quantitative criteria, calculating methods or formulas. In the present study, therefore, indexes for selecting suitable dam site through literature investigation and analyzing dam watersheds were determined, Expert questionnaire for various indexes were performed. Based on the above mentioned investigation and expert questionnaire, a methodology assigning weight using AHP method were proposed. The function of suitable dam (FSDS) site was calibrated and verified for four medium-sized watersheds. Finally, automated model for suitable dam site was developed using FSDS and 'Model builder' of GIS tool.

• Herbal Formula Science
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• v.26 no.4
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• pp.363-380
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• 2018

Objectives : We analyzed the principle of compatibility of socheongnyong-tang and expanded the range of application in clinical practice. Methods : Socheongnyong-tang was analyzed by the compatibility principle through the system of chief, deputy, assistant, and envoy, but the basic formulas of "Discussion of Cold Damage" and "Synopsis of the Golden Chamber" was used. Results : Socheongnyong-tang treats exterior wind-cold and interior water accumulation. Exterior wind-cold is treated mainly by exterior-releasing herbs constituting mahwang-tang and gyeji-tang in "Discussion of Cold Damage", and interior water accumulation is treated mainly by retained fluid-resolving herbs constituting yeonggamomigangsinha-tang, yeonggamomigagangsinbanhahaengin-tang and yeonggamomigagangsinbanhaengdaehwang-tang in "Synopsis of the Golden Chamber". Depending on the weight of exterior wind-cold and interior water accumulation, the disease condition is classified as a case where exterior wind-cold is heavier than interior water accumulation, a case where exterior wind-cold is lighter than interior water accumulation, and a case where it is equivalent. When exterior wind-cold is heavier than interior water accumulation, chief herbs are Ephedrae Herba and Cinnamomi Ramulus of exterior-releasing herbs series and deputy herbs are Zingiberis Rhizoma and Asari Radix et Rhizoma of retained fluid-resolving herbs series. When exterior wind-cold is equal to the disease condition of interior water accumulation, chief herbs are Ephedrae Herba of exterior-releasing herbs series and Zingiberis Rhizoma of retained fluid-resolving herbs series, and deputy herbs are Cinnamomi Ramulus of the exterior-releasing herbs series and Asari Radix et Rhizoma of retained fluid-resolving herbs series. When exterior wind-cold is lighter than interior water accumulation, chief herbs are Zingiberis Rhizoma and Asari Radix et Rhizoma of retained fluid-resolving herbs series and deputy herbs are Ephedrae Herba and Cinnamomi Ramulus of exterior-releasing herbs series. In any case, assistant herbs are Pinelliae Rhizoma, Paeoniae Radix alba, and Schisandrae Fructus, and envoy herb is Glycyrrhizae Radix preparata. Conclusions : In conclusion, socheongnyong-tang must differently formulate the system of chief, deputy, assistant, and envoy according to the grade of exterior wind-cold and interior water accumulation. These results suggest that socheongnyong-tang can be applied flexibly when applied in clinical practice to enhance the therapeutic effect.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.239-246
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• 2019

PURPOSE. The purpose of this study was to propose and assess a shade guide for pink gingival aesthetics using a Spanish population sample. MATERIALS AND METHODS. The $L^*$, $C^*$, h, $a^*$ and $b^*$ coordinates of 259 participants were measured using a spectrophotometer in 3 standardized points along the attached gingiva of the maxillary central incisors. A hierarchical clustering analysis was applied to obtain separate solutions regarding the number of shade tabs. For each of the solutions obtained, color differences (${\Delta}E^*$) were calculated using the CIELab and CIEDE2000 formulas, and the proposed shade guide was selected considering (1) the color differences between tabs and (2) the coverage error of each of the solutions. RESULTS. The proposed shade guide consisted of 8 gingival shade tabs and achieved CIELab and CIEDE2000 coverage errors of less than the respective 50:50% acceptability thresholds (${\Delta}E^*=4.6$ units and ${\Delta}E_{00}=4.1$). The coordinates for the various gingival shade tabs were as follows: Tab 1: $L^*43.3$, $a^*21.9$, $b^*12.3$ (1.6); Tab 2: $L^*42.9$, $a^*34.1$, $b^*19.1$; Tab 3: $L^*46.5$, $a^*25.8$, $b^*10.9$; Tab 4: $L^*46.5$, $a^*27.3$, $b^*15.1$; Tab 5: $L^*49.6$, $a^*23.5$, $b^*16.8$; Tab 6: $L^*51.5$, $a^*19.7$, $b^*13.6$; Tab 7: $L^*55.9$, $a^*22.0$, $b^*15.0$; and Tab 8: $L^*56.0$, $a^*19.9$, $b^*18.8$. CONCLUSION. The CIELab and CIEDE2000 coverage errors for the 8 shade tabs of the proposed gingival shade guide were significantly lower than those of other guides. Therefore, despite the limitations of this study, the proposed guide is more appropriate for matching gingival shade in the Spanish general population.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.203-209
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• 2019

In this work, a new land-specific resistance measuring device (GM) and a measuring probe (Grounding Rod) are connected to the WENNER quadrant as power-line communication (PLC). In groups of two (P1,P2) probes, five to ten probes are installed in series on the ground at intervals of 1m, 2m, 4m, 8m, and 16m, respectively. If the PLC signal from the GMD is detected by the receiver of the Probe 1 (P1) for measurement, the minute voltage and current for measurement flow from the PSD (power supply) attached to the probe to the ground, and then, through the soil between P1 and P2, enters the Probe 1 (P2). The resistance value is then measured by the principle of voltage drop due to ground resistance. Measure the earth resistance every T seconds up to 1 trillion and store the measured data on the Arduino Server mounted on the main equipment. Stored measurement data can be derived from formulas by Ohm's Law and from inherent resistance (here,). Data obtained in real time will be linked to CDGES programs installed on Main PC, enabling data analysis and real-time monitoring of the ground environment on land. In addition, a three-dimensional display is possible with 3D graph support by identifying seasonal characteristics such as temperature and humidity of land (soils). The limitations of the study will require specific application measures of Test Bed for commercial access to a model that has been developed and operated experimentally.

• Clean Technology
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• v.27 no.3
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• pp.269-274
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• 2021

Bioenergy is generally considered to be one of the options for pursuing carbon neutrality. However, for a period of time, combustion of harvested plant biomass inevitably causes more carbon dioxide in the atmosphere than combustion of fossil fuels. This paper proposes a method that predicts and minimizes the total amount and payback period of this carbon debt. As a case study, a carbon cycle impact assessment was performed for immediate switching of the currently used fossil fuels to biomass. This work points out a fundamental vulnerability in the concept of carbon neutrality. As an action plan for the sustainability of bioenergy, formulas for afforestation proportional to the decrease in the forest area and surplus harvest proportional to the increase in the forest mass are proposed. The results of optimization indicate that the carbon debt payback period is about 70 years, and the carbon dioxide in the atmosphere increases by more than 50% at a maximum and 3% at a steady state. These are theoretically predicted best results, which are expected to be worse in reality. Therefore, biomass is not truly carbon neutral, and it is inappropriate as an energy source alternative to fossil fuels. The method proposed in this work is expected to be able to contribute to the approach to carbon neutrality by minimizing present and future carbon debt of the bioenergy that is already in use.

• Journal of Korea Water Resources Association
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• v.54 no.5
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• pp.311-320
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• 2021

The agricultural water, which occupy about 61% of total water usage in the South Korea, is significantly objective to archieve effecitive water resources management. The objective of the study is to suggest a simple method in actual practice that could be used to estimate agricultural water usage in river considering hydrological condition. Historical record of agricultural water usage and runoff, which take account for hydrological condition of the basin, were obtained for totally 27 river basins. As the result, the high threshold value of the agricultural water usage rates compared to maximum usage amount has a particular correlations to the percent of normal year runoff for last 2 month, and threshold line of agricultural water usage rates was derived using the quantile regressions. Finally, two dimensionless threshold line and empirical formulas that described the correlation between the percent of normal year runoff for last 2 month and the agricultural water usage rate compared to maximum usage amount were derived. Also, the simple criteria to select which line and formula based on the characteristics of the basins was suggested but it need further studies. The result of the study could be used as an elemantary data in actual practice for water resoureces management.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.85-91
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• 2021

The purpose of this study is to derive an equation to verify the accuracy of the dose rate for each component calculated at the measurement point outside the maze door when designing the maze door of 6 MV X-ray beam. Based on the component-specific dose rate calculation formula for the measurement point outside the maze door described in NCRP Report 151 and IAEA Safety Report Series 47, the dose rate calculation formula for each component when applying the values of the drawing-based parameters and the dose rate calculation formula for each component when applying the values of conservative parameters are derived. From the two dose rate calculation formulas for each component, the dose rate verification formula for each component at the measurement point outside the maze door was derived. The resulting dose rate verification formula for each component at the measurement point outside the maze door can be compared and analyzed whether the dose rate for each component at the measurement point outside the maze door calculated by the designer falls within the range of the dose rate obtained from the derived dose rate verification formula for each component. This verification formula is considered to be practically useful in verifying the accuracy of the dose rate for each component calculated by the designer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.772-781
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• 2020

A direct shear member resists external forces through the shear transfer of reinforcing bars placed at the concrete interface. The current concrete structural design code uses empirical formulas based on the shear friction analogy, which is applied to the horizontal shear of concrete composite beams. However, in the case of a member with a large amount of reinforcing bars, the shear strength obtained through the empirical formula is lower than the measured value. In this paper, the limit state of newly constructed composite beams on an existing concrete girder is defined using stress field theory, and material constitutive laws are applied to gain horizontal shear strength while considering the tension-stiffening and softening effects of concrete struts. A simplified method of calculating the shear strength is proposed, which was validated by comparing it with the related design code provisions. As a result, it was confirmed that the method generally shows a similar tendency to the experimental results when the shear reinforcing bar yields, unlike the regulations of the design code, where differences in the predicted value of shear strength occur according to the shear reinforcement ratio.