• The Korean Journal of Emergency Medical Services
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• v.16 no.2
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• pp.53-66
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• 2012

Purpose : Emergency medical services in China are increase in demand by people and under the greater pressure than ever before. So it is, necessary to advance the pre-hospital system in order to promote the development of emergency medical services. Methods : This is based on China-related articles, books, journals, reports, statistical data and other literature. Results : First, pre-hospital emergency medical care with the introduction of specialist training program should be established. Second, to strengthen pre-hospital emergency services and to develop the EMS guidelines. Third, the "120" reporting systems unification and awareness activation. Fourth, the preparation of the EMS facilities equipment system. Fifth, the rapid transport system establishment to the selected medical institutions. Conclusion : It is necessary to strengthen the emergency medical personnel at the scene, rapid transport, rapid patient triage and to improve the survival rate of the patients.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.85-95
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• 2015

PURPOSES : Recently, bonded concrete overlay has been used as an alternative solution in concrete pavement rehabilitation since its material properties are similar to those of the existing concrete pavements. Deteriorated concrete pavements need rapid rehabilitation in order to prevent traffic jams on Korean expressways. Moreover, speedy and effective repair methods are required. Therefore, the use of bonded concrete overlay with ultra-rapid hardening cement has increased in an effort to reopen promptly the expressways in Korea. However, mobile mixer is required for ultra-rapid hardening cement concrete mixing in the construction site. The use of mobile mixer causes various disadvantages aforementioned such as limitation of the construction supply, open-air storage of mixing materials, increase in construction cost, and etc. In this study, therefore, hydration accelerator in-situ mixing on polymer modified concrete produced in concrete plant is attempted in order to avoid the disadvantages of existing bonded concrete overlay method using ultra-rapid hardening cement. METHODS : Bonded concrete overlay materials using ultra-rapid hardening cement should be meet all the requirements including structural characteristics, compatibility, durability for field application. Therefore, This study aimed to evaluate the application of hydration accelerator in-situ mixing on polymer modified concrete by evaluating structural characteristics, compatibility, durability and economic efficiency for bonded concrete overlay. RESULTS : Test results of structural characteristics showed that the compressive, flexural strength and bond strength were exceed 21MPa, 3.15MPa and 1.4MPa, respectively, which are the target strengths of four hours age for the purpose of prompt traffic reopening. In addition, tests of compatibility, such as drying shrinkage, coefficient of thermal expansion and modulus of elasticity, and durability (chloride ions penetration resistance, freezing-thawing resistance, scaling resistance, abrasion resistance and crack resistance), showed that the hydration accelerator in-situ mixing on polymer modified concrete were satisfied the required criteria. CONCLUSIONS : It was known that the hydration accelerator in-situ mixing on polymer modified concrete overlay method was applicable for bonded concrete overlay and was a good alternative method to substitute the existing bonded concrete overlay method since structural characteristics, compatibility, durability were satisfied the criteria and its economic efficiency was excellent compare to the existing bonded concrete overlay methods.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.21-30
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• 2015

PURPOSES : The purpose of this study was to evaluate the performance of rapid-setting polymer-modified asphalt mixtures with a high reclaimed asphalt pavement (RAP) content. METHODS: A literature review revealed that emulsified asphalt is actively used for cold-recycled pavement. First, two types of rapid-setting polymer-modified asphalt emulsion were prepared for application to high-RAP material with no virgin material content. The quick-setting polymer-modified asphalt mixtures using two types of rapid-setting polymer-modified asphalt emulsion were subjected to the following tests: 1) Marshall stability test, 2) water immersion stability test and 3) indirect tensile strength ratio test. RESULTS AND CONCLUSIONS : Additional re-calibration of the RAP was needed for laboratory verification because the results of analyzing RAP aggregates, which were collected from different job sites, did not deviate from the normal range. The Marshall stability of each type of binder under dry conditions was good. However, the Type B mixtures with bio-additives performed better in the water immersion stability test. Moreover, the overall results of the indirect tensile strength test of RAP mixtures with Type B emulsions exceeded 0.7. Further research, consisting of lab testing and on-site application, will be performed to verify the possibility of using RAP for minimizing the closing of roadways.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.36-44
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• 1999

The rapid Tooling technique is classified into two methods: one to directly utilize the model which was made by rapid prototyping technologies for dies, and the other to make a transferred type using the model as a master model and create dies and molds using it. In this study, the Al powder filled resin was made several mixed ratios and meshes sizes, and applied to slurry casting. And, variation of mechanical characteristics such as the shrinkage rate, the tensile strength, the elongation, the hardness, and surface roughness, are measured to compare. Consequently, as higher is the powder mixed ration and as smaller is the grain size of the power, the mechanical characteristics of the final mold are improved. Finally, the metal short fiber which can be fabricated easily and cheaply, if the self-excited vibration of an elastic tool, was also applied to slurry casting. It has been found tat the hardness gets higher, while the shrinkage rate lower, if mixed with short fiber.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.10
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• pp.912-920
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• 2012

In this paper, we propose a new and cost-effective RCP (Rapid Control Prototyping) system based on Matlab/Simulink and a DAQ (Data Acquisition) unit with the high speed USB communication interface. The proposed RCP system has a feature that a computer on which Simulink is running acts as a realtime controller and a DAQ unit performs data acquisition, transmission of the data to and from a computer, and the application of control data received from the computer. For its implementation, we develop 10 communication blocks each of which is constructed by using S-function. In order to increase the data communication speed and thus to reduce the sampling period of the overall control system, we propose to use a batch transfer strategy through the USB interface. The proposed RCP system has several advantages over existing methods such as good maintainability, portability due to the USB interface, low cost, and no necessity for C-code generation even though it can only be applied to control systems with moderate sampling rates. It is expected that the proposed RCP system can be useful in teaching control-related topics to undergraduate and graduate students.

• International Journal of CAD/CAM
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• v.1 no.1
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• pp.1-9
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• 2002

The STL or Stereolithography format, established by 3D systems, gathers the geometric data of the model in a number of triangular surfaces. It can be in ASCII or binary format, and is a de facto standard in the Rapid Prototyping (RP) world. RP has developed greatly over the last ten years. In particular, improvement in materials has meant greater part accuracy and strength, which in turn has increased the range of functional applications. Future applications of RP will focus on rapid tooling and direct manufacturing. Direct manufacturing in particular may see much benefit from the incorporation of color into models. For color RP, besides designing new hardware to add color into the prototypes, it is necessary to redefine the CAD software for adding and accurately positioning color onto the model. STL cannot effectively store this kind of information. Among the existing data file formats, VRML is an acceptable one that is complimentary to existing RP processes. This paper acts as a review to discuss several methods of using VRML for coloring model data. This paper will also discuss the problems occurred in coloring the layer contours of the RP model.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• Korean Journal of Radiology
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• v.1 no.4
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• pp.185-190
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• 2000

Objective: To document the imaging findings of hepatic cavernous hemangioma detected in cirrhotic liver. Materials and Methods: The imaging findings of 14 hepatic cavernous hemangiomas in ten patients with liver cirrhosis were retrospectively analyzed. A diagnosis of hepatic cavernous hemangioma was based on the findings of two or more of the following imaging studies: MR, including contrast-enhanced dynamic imaging (n = 10), dynamic CT (n = 4), hepatic arteriography (n = 9), and US (n = 10). Results: The mean size of the 14 hepatic hemangiomas was 0.9 (range, 0.5-1.5) cm in the longest dimension. In 11 of these (79%), contrast-enhanced dynamic CT and MR imaging showed rapid contrast enhancement of the entire lesion during the early phase, and hepatic arteriography revealed globular enhancement and rapid filling-in. On contrast-enhanced MR images, three lesions (21%) showed partial enhancement until the 5-min delayed phases. US indicated that while three slowly enhancing lesions were homogeneously hyperechoic, 9 (82%) of 11 showing rapid enhancement were not delineated. Conclusion: The majority of hepatic cavernous hemangiomas detected in cirrhotic liver are small in size, and in many, hepatic arteriography and/or contrast-enhanced dynamic CT and MR imaging demonstrates rapid enhancement. US, however, fails to distinguish a lesion of this kind from its cirrhotic background.

• Communications for Statistical Applications and Methods
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• v.31 no.4
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• pp.377-391
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• 2024

Accurate household projections are essential for sectors such as housing supply and tax policy planning, given the rapid social changes like declining birthrates, an aging population, and a rise in single-person households that impact household size and type. Korea introduced its first register-based census in 2015, transitioning from five-year general survey-based approach to an annual administrative data-based census. This change in census allows for more frequent and effective capturing the rapid demographic shifts and trends. However, this change in census has caused challenges in future projection by the existing household projection model due to the rapid dynamics. This paper proposes a new household projection method, the N-point Modified Exponential Model (MEM), that accurately reflects register-based census data and mitigates the impact of rapid demographic changes, in three types: the Weighted N-point MEM, the Regression-based N-point MEM, and the Rolling Weighted N+point MEM. Using register-based census data from 2016 to 2020 to forecast household headship rates by age, household size, and household type to 2051, the N-point modified exponential model outperformed the existing model in both long- and short-term forecast accuracy, suggesting its suitability as a future household projection model for Korea.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1258-1258
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• 2001

Estimation of sugar and reducing sugar content in molasses is very important task in sugar refineries. Conventional methods of determination of sugar content in molasses samples are highly time consuming and employ hazardous chemicals. Due to the physical properties of molasses, probability of error in conventional analytical techniques is high. These methods have proven to be inefficient for a process control in any sugar industry. Hence development of a rapid, inexpensive, physical and also accurate method for sugar determination in molasses will be highly useful. Near Infrared spectroscopy is being widely used worldwide as an analytical technique in food industry. The technique offers the advantage of being non-destructive and rapid. The present paper highlights the potential of near infrared reflectance spectroscopy as a rapid and automated analytical technique for determination of sugar and reducing sugar content in molasses. A number of molasses samples were collected during and after the sugar season from Havana Sugar Industry, Havana. The samples were chosen so as to obtain a wide range of concentration of sugar and reducing sugars. This was done in order to achieve a good calibration curve with widely spread data points. These samples were scanned in the region of 1100 - 2500 nm in diffuse reflectance mode. An indigenous ELICO NIR spectrophotometer, modified according to the requirements of sugar industry was used for this purpose. Each sample was also analyzed simultaneously by standard chemical methods. Chemical values were taken as reference for near infrared analysis. In order to obtain the most accurate calibration for the set of samples, various mathematical treatments were employed. Partial Least Square method was found to be most suitable for the analysis. A comparison is made between the actual values (chemical values) and the predicted values (NIR values). The actual values agree very well with the predicted values showing the accuracy of the technique. The validity of the technique is checked by predicting the concentration of sugar in unknown molasses samples using the calibration curve. The present investigation assesses the feasibility of the technique for on-line monitoring of sugars present in molasses in sugar industries.