• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4C
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• pp.247-254
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• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• Research in Community and Public Health Nursing
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• v.6 no.1
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• pp.34-54
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• 1995

Occupational health services in Korea have been operated as dual types: one is operated by occupational health care manager and the other is health care agency without their own personnel. The performance of occupational health service should be different due to the variety of characteristics of health care manager and workplace, qualification of health care manager. This study is to analyze performance of occupational health care services with a particular consideration of job, based on comparing those two types of health care management to show on the basic data for the settlement of more qualitative. health care management system at workplace. For this study, total 391 places in Seoul and Inchon city area: 154 places (39.4%) managed by designated. health care manager and 237 places (60.6%) by the agency with their commission are selected as research samples. Tools for data collection are questionnares have been investigated during the period of 20 September 1993-20 December 1993. Those data are compared with percentiles, mean, standard deviation due to the characterstics of each variable and analyzed for impacting factors with relation to the using multiple regression analysis using SPSS PC program, especially using t -test method in order to compare each type of health care management. Conclusions observed from the tests and each comparison could be summerized as follows : 1. Occupational health care have been accomplished at workplaces with designated people than with agencies people, and coverage rate of the occupational health care services has differences, due to management types. The reason of these results is due to visit only one or two times monthly by the agencies, while their own health care manager obsess, at the workplaces all the times. 2. The common sickness management is the most accomplished item in health care area of occupational health care services, while the preventive care and control for the workers who have serious health problems are insufficient in workers health care area. 3. An insufficient accomplishment of overall health education has been shown because it is difficult to perform health education due to almost no chance of the direct introduction at workplaces. Therefore a strong support system for making and supplying the media is necessary in order to activate indirect health education by means of media. 4. Because health care managers and the agencies managers where take the workplaces for this study are almost nurses who have been comparatively high work site rounding rate about an environmental management at the workplaces, that non-profession can also do it, the activities about the professional area not enough. Therefore, an appropriate referral system should be established in order to complement professional area. 5. Two factors which have an effect on the coverage rate of occupational health care services are : one is those from the workplaces such as type of services, the number of workers, the number of harzadous factors and safety & health committee, the other from health care organization about whether there is its own manager or not.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.275-281
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• 2012

Thermal distribution in soils must be considered in engineering designs and constructions, including estimates of frost heave and thaw settlement, infrastructure in cold regions, and geothermal systems. Because thermal conductivity is a key parameter for evaluation of thermal distribution in soils, it must be accurately estimated. The thermal conductivity of fine-grained soils has been widely studied in recent years; however, few studies have reported a reliable method for experimental measurement. The present study presents the results of an experimental investigation of the thermal conductivity of a saturated kaolinite-silica mixture with respect to the variation of dry density. Thermal conductivities were measured in Constant Rate of Strain (CRS) consolidation tests, and the experimental data were analyzed to evaluate the accuracy of the new measurement system. In addition, we present an evaluation method for predicting thermal conductivity in fine-grained soils.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.3
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• pp.263-278
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• 2022

This paper contains experimental study for the development and performance of TBM backfill material with thixotropic properties. The LW backfill material is widely applied to fill the cavity on the back side of the shield TBM excavation, but has disadvantages such as settlement caused by strength reduction, material separation by groundwater, and reduced plasticity. In this paper, laboratory tests and a model test were conducted to assess the performance of inorganic thixotropic backfill material proposed to improve these problems. The results of laboratory tests show that 1 hr-uniaxial compressive strength of ITB was 12 times higher than LW, and the rate of bleeding of 20 hr was 8.3 times lower, and the result of flow table test was more than 27 times higher. This result indicated that the inorganic thixotropic backfill material has superior properties to LW backfill in terms of strength reduction, material separation, and thixotropy. In the model experiment, a model injection device tester was manufactured and the injection performance and filling rate were verified. When material was injected in the water, it was visually checked whether material separation occurred, and it was confirmed that the filling rate was 96% or more. Comparison results with the test of LW and ITB materials was concluded that ITB can reduce the material separation by groundwater and the occurrence of tunnel cavity.

• Journal of the Korean Geotechnical Society
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• v.39 no.7
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• pp.69-76
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• 2023

Cavity causes settlement and its remediation after an accident results in significant time and economic losses. This study aims to experimentally evaluate the prospect of using infrared camera to detect and measure underground subsidence. Emissivity is necessary to detect the energy emitted from an object and accurately assess temperature using an infrared camera. The emissivity in laboratory tests is fixed to evaluate a reasonable distance between the infrared camera and the object, and temperature values are assessed at various distances. In field experiments, the cavity of the field experiment is simulated using a PVC pipe with a diameter of 5 cm, artificially buried at depths of 5 and 25 cm from the surface. The infrared camera measurements are taken from 4 PM to 3 PM of the next day (a total of 23 h). The analysis included the time-series temperature distribution and the cooling rate index assessment, which represents the temperature change rate per unit of time. The results showed that various temperature trends are observed depending on the location of the subsidence. This study demonstrates that the infrared camera can be used to assess the condition of the subsurface.

• Journal of Families and Better Life
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• v.23 no.4 s.76
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• pp.1-15
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• 2005

Korean society is experiencing rapid changes which are certain to shape the lives of the older people and their families. So, the purpose of this study was to improve the quality of the elderly welfare service in Korea. Even though the interest about the elderly welfare in Korea is rapidly on the increase, the reality of Korean Society still leaves much to be desired, quantitatively as well as qualitatively. Pay attent to this point, now going to grasp the situation of not the handicapped elder people but the general elder people actual life condition and demand for welfare. So this study focused on the demand of not out-of home service but in-home care service. It was based on the data from by Korea National Statistical Office, having observed 6,139 elderly people. The results were as follows. They hope to get the elderly welfare services about health examination service, nursing survice, supporting service for household. That was, the most of them wanted in-home care service than out-of home care service. To ensure effective care to the elderly, it needed development and settlement of welfare service in face of their daily living. And, even though they recognized that they should cover the elderly life expenses themselves, the rate was hit that indicated their adult children as a parents supporter. This means that we should consider not only to the elder people but also to the family which contained the old people as the elderly welfare service. As a remedy, we can find the cooperation between elder welfare service at the social welfare organization and counsel, education at the family strengthen center. To improve the quality of the elderly welfare service in Korea, the elderly welfare service should focus not only on the physical and spiritual health maintenance but also active understanding living environment and growing ability to arbitrate between individual and living.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.3
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• pp.187-197
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• 2013

This study examined the ideal type of a man that women prefer and the recognition of men for their own appearance management with the rise of the importance for appearance management today. The prerequisite which matters most in time of considering a man as a date of love predominantly was centered on education, and the prerequisite which goes first among the rest in time of judging a man as the mate of marriage was undoubtedly his financial status. It is regarded that as for a date of love the visual image or the specialty other than the conditions in reality mattered most, and concerning a mate in marriage the actual financial conditions had the priority. When a man is evaluated, the percentage of appearance took the highest rate of 60~80%, and in his appearance, the general harmony was considered as the most important factor. As for the recognition of men for their appearance management, women tend to have an affirmative realization for managing their own appearance in general, and the reason was they believe that the way men take care of their own appearance belongs to personal free will. The perception for a man with a decent appearance was very positive, and the ground for this was that once the appearance looks handsome, he seems gorgeous. The recognition for men's cosmetic surgery showed the affirmation over the average, and an opinion that the settlement of personal appearance complex will help them out emerged as the ground for this affirmation, and so it is regarded that the aesthetic surgery of today and the perception for men's appearance management have become universal phenomena unlike former days with the reflection of visualization of the external visual and lookism shown from various media.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.197-206
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• 2020

Reutilization of solid waste such as Tire Derived Aggregate (TDA) and mixing it with soft soil for backfill material not only reduces the required volume of backfill soil (i.e., sand-mining procedures; reinforcement), but also preserves the environment from pollution by recycling. TDA is a widely-used material that has a good track record for improving sustainable construction. This paper attempted to investigate the performance of Kaolin-TDA mixtures as a backfill material underneath a strip footing and close to a retaining wall. For this purpose, different types of TDA i.e., powdery, shredded, small-size granular (1-4 mm) and large-size granular (5-8 mm), were mixed with Kaolin at 0, 20, 40, and 60% by weight. Static surcharge load with the rate of 10 kPa per min was applied on the strip footing until the failure of footing happened. The behaviour of samples K80-G (1-4 mm) 20 and K80-G (5-8 mm) 20 were identical to that of pure Kaolin, except that the maximum footing stress had grown by roughly three times (300-310 kPa). Therefore, it can be concluded that the total flexibility of the backfill and shear strength of the strip footing have been increased by adding the TDA. The results indicate that, a significant increase in the failure vertical stress of the footing is observed at the optimum mixture content. In addition, the TDA increases the elasticity behaviour of the backfill.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.138-149
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• 2003

As the Internet is quickly evolving from best-effort networks to business quality networks, billing based on the precise traffic measurement becomes an important issue for Internet Service Providers (ISPs). Billing settlement is necessary not only between ISP and customers but also between ISPs. Currently, most ISPs use a flat rate charging policy. Besides the degree of difficulty in deriving appropriate charging policies agreeable by a concerned party, there are substantial technical challenges to come up with a good usage-based accounting system. Usage-based accounting depending on IP packet header information only is not sufficient anymore due to highly dynamic nature of the development and the use of the Internet applications such as peer-to-peer and network games. They are using port numbers dynamically and even several applications can use the same port number. Thus, more precise means of classifying them and accounting their traffic usages are required. In this paper, we propose a high performance, adaptable, configurable, and scalable content-aware application traffic measurement and analysis system which can achieve very accurate usage-based accounting.

• Journal of the Korean GEO-environmental Society
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• v.17 no.2
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• pp.31-39
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• 2016

Vertical drain has usually been used to accelerate the consolidation of soft clay deposits with high moisture content. Busan thick clay deposits are subjected to artesian pressure from an aquifer in sand and gravel layers. However, effect of artesian pressure existing in drainage-installed soft ground on consolidation behaviors is not well known. This paper investigates the consolidation behavior of drainage-installed soft ground at the Nakdong river estuary with artesian pressure and without artesian pressure. A series of one-dimensional large size column test was carried out to find out the consolidation characteristics of clay. Test results indicated that total settlement of clay with artesian pressure was higher than that without artesian pressure because effective stress decreased due to upward flow. Dissipation rate of excess pore water pressure delayed and excess pore water pressure did not fully dissipate in clay layer with artesian pressure. Undrained shear strength of clay ground with artesian pressure was lower than that without artesian pressure.