• Journal of the Korean Geotechnical Society
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• v.39 no.5
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• pp.13-26
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• 2023

This study examined the soil-water characteristic curve (SWCC), considering the volume change, using wetting curves on the field monitoring data of a wireless sensor network. Special attention was given to evaluating the landslide vulnerability by deriving a matric suction suitable for the actual site during the wetting process. Laboratory drying SWCC and shrinkage laboratory tests were used to perform the combined analysis of landslide and debris flow. The results showed that the safety factor of the wetting curve, considering the volume change of soil, was lower than that of the drying curve. As a result of numerical analyses of the debris flow simulation, more debris flow occurred in the wetting curve than in the drying curve. It was also found that the landslide analysis with the drying curve tends to overestimate the actual safety factor with the in situ wetting curve. Finally, it is confirmed that calculating the matric suction through SWCC considering the volume change is more appropriate and reasonable for the field landslide analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.539-545
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• 2010

The field plate test has a good potential for determining since it measures both plate pressure and settlement. The deformation modulus of rock mass is differently measured for status of structures. The values of deformation modulus are obtained from laboratory test (uniaxial and triaxial test) and field test (pressuremeter test). Plate load test should be conducted by different loading plate sizes for geological structure of rock mass and scale of structures. In this paper, large plate load tests were performed to predict of structure's behavior and evaluate the ultimate bearing capacity of the foundation on soft rock. Simultaneously, deformation modulus of rock mass was estimated by back analysis of stresses measured in field test under rock mass. Finally, we verified the validation of deformation modulus of rock mass through result of large plate load test and numerical simulation.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.158-167
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• 2008

The quality control of compacted fills has been carried out by evaluating relative densities and coefficients of soil reaction. These measures have several limitations regarding repeatability and reliability of field measurements, and difficulties to use in the fills including large grain size as gravels and boulders. Also, the density is not directly related to the design parameter such as resilient modulus. A preliminary investigation for the usage of the stiffness as a control measure has been carried out. In the laboratory, the stiffness (P-wave velocity) was measured during compaction tests. The stiffness at the optimal moisture content was proposed to use a target control parameter likewise maximum dry density. A field method to match the target stiffness was also proposed by considering easiness of the method and availability of equipment. The most phenomenal feature of the method is that the control parameter (stiffness) is closely related to resilient modulus and can be consistently used from the design stage to the field control during construction.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.105-113
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• 2006

The footing of a bridge is a very essential part that support the whole load induced by the bridge itself and the traffic as well. However, once a bridge is built, the footing is buried under soil so the footing is invisible from outside. Therefore, the safety or condition of the footing is very difficult to estimate. Not only the length of the imbedded part of the footings but also the type of footings are unknown once the design record is gone. Some nondestructive techniques can be used to evaluate invisible part of the footings but the results have not been successful yet. Using GPR (Ground Penetrating Radar), which has been used for the nondestructive evaluation in military purposes, the condition assessment of the footings have been successfully conducted in this research. The field evaluation and laboratory tests have been conducted to find effective factors in the condition assessment of the footings. The equipment and basic theory of the GPR has been presented. The field test results show that the GPR can be successfully used for the safety evaluation of the footings. More test results and field data are needed for more precise evaluation of the footings.

• Smart Structures and Systems
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• v.13 no.2
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• pp.281-303
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• 2014

In order to suppress the wind-induced vibrations of the Canton Tower, a pair of active mass driver (AMD) systems has been installed on the top of the main structure. The structural principal directions in which the bending modes of the structure are uncoupled are proposed and verified based on the orthogonal projection approach. For the vibration control design in the principal X direction, the simplified model of the structure is developed based on the finite element model and modified according to the field measurements under wind excitations. The AMD system driven by permanent magnet synchronous linear motors are adopted. The dynamical models of the AMD subsystems are determined according to the open-loop test results by using nonlinear least square fitting method. The continuous variable gain feedback (VGF) control strategy is adopted to make the AMD system adaptive to the variation in the intensity of wind excitations. Finally, the field tests of free vibration control are carried out. The field test results of AMD control show that the damping ratio of the first vibration mode increases up to 11 times of the original value without control.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.261-270
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• 2020

This study reviewed the quality addition rate, calculation, and application criteria needed to identify the possibility of additional medical technologists in the field for new certification and professional manpower to provide a superior laboratory. The six institutions that participated in the study were the size of large hospitals with more than 1,000 beds, with an average of five full-time laboratory physicians (also called clinical pathologists) and an average of 53 medical technologists, with 10.6 per laboratory physician. An analysis of the time required for each activity category of medical technologists revealed decreasing behavior during the analysis. In contrast, the ratio of the comprehensive pre-analysis activities was high due to the strengthening of laboratory operations and quality control. During the analysis, the proportion of biochemistry tests was high, and post-analysis of most of the results was performed. Hence, improving the quality of sample testing requires significant time, and appropriate personnel are required. In conclusion, the recruitment of medical technologists is also a key component to improving the sample quality, and corresponding personnel regulations are necessary.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.220-227
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• 2005

Recently, the use of an electrical apparatus has brought up concerns of health risks from exposure to electromagnetic fields. EMF is composed of electric fields and magnetic fields. Heavy exposure to EMF can occur only in the vicinity of high-voltage overhead transmission lines, close to transformers and underground cables, and also close to large electrical machinery. In this thesis I have investigated the hypothesis of the correlation between occupational exposure to ELF-EMF and the risks of leukemia, anemia, cancer. Therefore, the aim of this study is to investigate whether or not ELF-EMF emitted from electric power stations and transformer substations affect some hematological parameters and tumor markers of electric utility workers. The hematological test results and tumor markers under investigation were similar in the two groups but some of parameters such as RBC, AFP, LDH showed significant difference between the two groups from two sample t-test (p<0.05). The exposure group showed increased LDH level compared to the control group by two sample t-tests. In addition, the abnormal LDH level in the exposure group was observed to be clinically significant by ${\chi}^2$-test. However, the levels of RBC, AFP observed were not clinically significant by ${\chi}^2$-test (p>0.05). These results suggested that ELF-EMF does not affect most blood test parameters except LDH of electric utility workers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.134-141
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• 1989

In order to estimate field seedling emergence and grain yield by the information collected from various laboratory seed vigor tests, each two malting and naked barley cultivar seeds were artificially aged according to the standard aging treatment suggested by the Association of Official Seed Analysts. The seed vigor tests adopted were warm- and cold-germination test, tetrazolium vigor test and electrocon. ductivity test. Field emergence of malting barley (Y) was estimated by Y=-2.962+0.229X$_1$ (% warm germination) -0.001X$_2$ (vigor of warm germination test: WGT) +0.354X$_3$ (vigor of cold germination test: CT) -0.558X$_4$ (% cold germination). The multiple correlation coefficient indicated that % warm germination. was contributed 64 % of the variation in seedling emergence rate of malting barley. The vigor of warm and cold germination tests, and % cold germination contributed additional 4, 7, and 9%, respectively, upon addition of the variables into regression. For naked barley, the regression equation of emergence rate was less efficient(R$^2$=54%) than that of malting barley(R$^2$=84%). A model to predict grain yield by the results of various seed vigor tests was not evaluated for both malting and naked barlev.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.579-586
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• 2012

The main objective of the research is to evaluate the laboratory performances of epoxy asphalt mixtures for long-span steel bridge decks. The aggregate gradations were recommended for field applications. The laboratory performance test results showed that the durability of epoxy asphalt mixtures was more noticeable than that of conventional ones. The structural analysis was conducted using resilient modulus and bond-shear test results. The analysis results revealed that just 9% out of total bond-shear stress was enough for the entire required bond-shear stress in the pavement system. The tensile stresses in the bridge decks were within limits compared to the laboratory test results from the Nanjing Grand Bridge in China. As a result, the laboratory performances of the epoxy asphalt mixtures for long-span steel bridge decks were better than those of conventional asphalt mixtures. However, the laboratory performance tests of epoxy asphalt mixtures for long-span steel bridge decks should be conducted precisely since the strengths of the mixtures are sensitive to the temperatures and curing times.

• Korea Journal of Hospital Management
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• v.5 no.1
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• pp.129-155
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• 2000

This empirical study, activity-based costing, a newly introduced approach that has proved to be an improvement over the conventional costing system in product or service costing, is applied at department of clinical pathology in K university hospital. The study subjects were 233 test procedures done in clinical laboratory of K university hospital. Activity analysis was done by interview, questionnaires, and time study, and the amount of resources consumed by each activity and their costs are then traced and applied to the laboratory tests. The main purpose of this study were to compare the test costs of activity-bases costing with those of conventional costing, and test fees of medical insurance, and to provide accurate cost informations for the decision makers of hospital. The major findings of this study were as belows. 1. The cost drivers for application of activity-based costing at clinical laboratory were cases of sample collection, case of specimen, cases of test, and volume-related allocation bases such as direct labor hours and total revenue of each test. 2. The profits of each clinical laboratory fields analyzed by conventional costing were different from the profits analyzed by activity-based costing, especially in the field of Urinalysis(approximately over estimated 750%). 3. The standard full costs by conventional costing were quite different from the costs computed by using activity-based costing, and the difference is most significant with the tests of long labor time. 4. From the comparison between costs computed by using activity-based costing and medical insurance fees, some test fees were significantly lower than the costs, especially in the non-automated fields. As described in this study, activity-based costing provides more accurate cost information than does conventional costing system. The former approach is especially important in the health care industry including hospitals in which planning and controlling the costs services provided are the key to maintaining a healthy financial status for the organization. Despite the contribution of activity-based costing the economic as well as technical feasibilities of implementing such a cost accounting system in an organization must be evaluated. In the development of activity-based costing systems, an activity analysis has to be conducted to identify activities that consume resources. This involves a detailed study of the organization's logistics and accounting information systems, and it is an expensive project in itself. Besides, it can be quite difficult and time consuming to identify and trace resource consumption to a specific activity. Thus the activity-based costing system should be implemented only when the decrease in cost of error far exceeds the increase in cost of measurement. By combining activity-based costing with standard costing, health care administrators can better plan and control the costs of health services provided while ensuring that the organization's bottom line is healthy.