• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.215-223
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• 2013

An experimental research on the possibility of using fiber reinforced concrete precast tunnel segments instead of traditional reinforced concrete(RC) segment has been performed in europe. This solution allows removing the traditional reinforcement with several advantages in terms of quality and cost reduction. Full-scale bending tests were carried out in order to compare the behaviour of the segments under flexural actions on both rebar reinforced concrete and rebar-fiber reinforced elements. The test results showed that the fiber reinforced concrete can substitute the traditional reinforcement; in particular the segment performance is improved by the fiber presence, mainly in terms of crack.

• Journal of Powder Materials
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• v.9 no.6
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• pp.441-448
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• 2002

Dispersions of non-soluble ceramic particles in a metallic matrix can enhance the strength and heat resistance of materials. With the advent of mechanical alloying it became possible to put the theoretical concept into practice by incorporating very fine particles in a flirty uniform distribution into often oxidation- and corrosion- resistant metal matrices. e.g. superalloys. The present paper will give an overview about the mechanical alloying technique as a dry, high energy ball milling process for producing composite metal powders with a fine controlled microstructure. The common way is milling of a mixture of metallic and nonmetallic powders (e.g. oxides. carbides, nitrides, borides) in a high energy ball mill. The heavy mechanical deformation during milling causes also fracture of the ceramic particles to be distributed homogeneously by further milling. The mechanisms of the process are described. To obtain a homogeneous distribution of nano-sized dispersoids in a more ductile matrix (e.g. aluminium-or copper based alloys) a reaction milling is suitable. Dispersoid can be formed in a solid state reaction by introducing materials that react with the matrix either during milling or during a subsequent heat treatment. The pre-conditions for obtaining high quality materials, which require a homogeneous distribution of small dis-persoids, are: milling behaviour of the ductile phase (Al, Cu) will be improved by the additives (e.g. graphite), homogeneous introduction of the additives into the granules is possible and the additive reacts with the matrix or an alloying element to form hard particles that are inert with respect to the matrix also at elevated temperatures. The mechanism of the in-situ formation of dispersoids is described using copper-based alloys as an example. A comparison between the in-situ formation of dispersoids (TiC) in the copper matrix and the milling of Cu-TiC mixtures is given with respect to the microstructure and properties, obtained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.753-758
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• 2006

The recent drastic increase of imported foreign restaurants provided the importance of service quality and the customer satisfaction is considered as the most important factors for the business activity. In order to identify the important factors for the customer satisfaction of the family restaurant in Korea, we attempt to test the validity of host call service as a significant variable in the family restaurant using Fishbein behaviour model. Based on literature review, the empirical study was conducted using the questionnaires for customers of the family restaurant in Seoul. Descriptive statistics, t-test, F-test and regression analysis were made of the gathered questionnaires using SPSS programs. The results shows that four hypotheses established in this study were significant. Therefore, host call service in the family restaurant should be introduced to increase the customer satisfaction. In conclusion, it proved that host call service in the family were the important factors that could satisfy the customers and the family restaurants will have to make a great effort to develop the differentiated service so as to enhance their competitiveness.

• KIEAE Journal
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• v.13 no.6
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• pp.55-65
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• 2013

Korean Government has developed Sejong City as a new administration city. This city of future was planned and designed toward one of the most eco-friendly city on the basis of ICTs. To attain this object, a carbon emission monitoring system (CEMS) was designed and installed as a part of u-city service which provides various information anytime and anywhere to enrich the people's quality of life. In this paper, at first, the structure and functions of CEMS are introduced. This system is consist of 5 parts - data collection from user and linked public DBs, transforming data into meaningful information for the policy makers, system-user interfacing via statistical tables and graphs, and system maintenance. This system can be operated by the citizen participation through whole the process. With the help of GIS map and graphic interface, statistics of monitored data for both citizen and decision maker provided and after feed-back, they have affected on the behaviour of citizen's energy consumption and related policy as well. By the CEMS, energy consumption data of 124 agreed households were collected during 9 months in 2012. Electricity, gas and water consumption were remote-metered automatically by the system and analysed. This showed that more than 85% of CO2 emission is rely on electricity usage. Furthermore, number of family members and size of house influences on the emission of CO2 by each household together with the life-style of the occupants. Electricity and water consumption showed the seasonal factor while gas consumption represents the number of family members. Even this paper has limitations caused by 9 months of data collection, it shows the policy directions to reduce the emission of CO2 focusing on the house size and number of family members of each households. With the result of this research, life-style of the generation of dwellers should be investigated and the CO2 emission characteristics of other housing type as well for the data building for future policy making.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.72-83
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• 2015

Underground transmission lines always generate heat and transmit heat through surrounding backfill materials. Therefore, in the design of power lines it becomes a very crucial factor to transfer heat effectively into the neighbouring soils. In this study, in order to enhance field applicability of recycled aggregates for backfill material of transmission lines, quality criteria and construction criteria were proposed, and thermal stability of power lines through field demonstration tests were analyzed. In the field tests, two types of recycled aggregates and sand which is currently used for backfilling were compared in terms of thermal behaviour. Test results showed that recycled aggregates represented similar trends with sand in temperature and moisture content corresponding to time lapse and distance from the heat source. Consequently, recycled aggregates can be utilized for backfill materials of underground transmission lines as a substitute material of sands.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.255-261
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• 2003

Tunnelling in poor and heterogeneous ground is a difficult task. Even with a good geological investigation, uncertainties with respect to the local rock mass structure will remain. Especially for such conditions, a reliable short-term prediction of the conditions ahead and outside the tunnel profile are of paramount importance for the choice of appropriate excavation and support methods. The information contained in the absolute displacement monitoring data allows a comprehensive evaluation of the displacements and the determination of the behaviour and influence of an anisotropic rock mass. Case histories and with numerical simulations show, that changes in the displacement vector orientation can indicate changing rock mass conditions ahead of the tunnel face (Schubert & Budil 1995, Steindorfer & Schubert 1997). Further research has been conducted to quantify the influence of weak zones on stresses and displacements (Grossauer 2001). Sellner (2000) developed software, which allows predicting displacements (GeoFit$\circledR$). The function parameters describe the time and advance dependent deformation of a tunnel. Routinely applying this method at each measuring section allows determining trends of those parameters. It shows, that the trends of parameter sets indicate changes in the stiffness of the rock mass outside the tunnel in a similar way, as the displacement vector orientation does. Three-dimensional Finite Element simulations of different weakness zone properties, thicknesses, and orientations relative to the tunnel axis were carried out and the function parameters evaluated from the results. The results are compared to monitoring results from alpine tunnels in heterogeneous rock. The good qualitative correlation between trends observed on site and numerical results gives hope that by a routine determination of the function parameters during excavation the prediction of rock mass conditions ahead of the tunnel face can be improved. Implementing the rules developed from experience and simulations into the monitoring data evaluation program allows to automatically issuing information on the expected rock mass quality ahead of the tunnel.

• Smart Structures and Systems
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• v.13 no.4
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• pp.587-614
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• 2014

In recent years the interest in online monitoring of lightweight structures with ultrasonic guided waves is steadily growing. Especially the aircraft industry is a driving force in the development of structural health monitoring (SHM) systems. In order to optimally design SHM systems powerful and efficient numerical simulation tools to predict the behaviour of ultrasonic elastic waves in thin-walled structures are required. It has been shown that in real industrial applications, such as airplane wings or fuselages, conventional linear and quadratic pure displacement finite elements commonly used to model ultrasonic elastic waves quickly reach their limits. The required mesh density, to obtain good quality solutions, results in enormous computational costs when solving the wave propagation problem in the time domain. To resolve this problem different possibilities are available. Analytical methods and higher order finite element method approaches (HO-FEM), like p-FEM, spectral elements, spectral analysis and isogeometric analysis, are among them. Although analytical approaches offer fast and accurate results, they are limited to rather simple geometries. On the other hand, the application of higher order finite element schemes is a computationally demanding task. The drawbacks of both methods can be circumvented if regions of complex geometry are modelled using a HO-FEM approach while the response of the remaining structure is computed utilizing an analytical approach. The objective of the paper is to present an efficient method to couple different HO-FEM schemes with an analytical description of an undisturbed region. Using this hybrid formulation the numerical effort can be drastically reduced. The functionality of the proposed scheme is demonstrated by studying the propagation of ultrasonic guided waves in plates, excited by a piezoelectric patch actuator. The actuator is modelled utilizing higher order coupled field finite elements, whereas the homogenous, isotropic plate is described analytically. The results of this "semi-analytical" approach highlight the opportunities to reduce the numerical effort if closed-form solutions are partially available.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3269-3274
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• 2013

Background: The aim was to determine the lifestyle behaviors and the practices for early diagnosis of cancer of cancer patients. Materials and Methods: A descriptive cross-sectional design was used for this study. The sample consisted of 222 patients with a diagnosis of cancer (non-random sample method). Ethical permission was obtained of the Non-interventional Research Ethics Committee of our Institution. Values of p<0.05 were accepted as statistically significant. Results: It was observed that 54.4% of the patients had never performed breast self-examination, 60.8% had never had a mammography, and 71.2% had never had a Pap smear. Sixty-six point two percent of patients had never had screening for colon cancer within the past ten years. GIS cancers were higher in smokers and ex-smokers (p=0.005), in drinkers and in ex-drinkers (p=0.000). The breast cancer rate was higher in obese people (p=0.019). Conclusions: The results of this study provide information on the healthy lifestyle behavior of cancer patients before their diagnosis, and their use of early diagnosis practices. The important aspect of this study is to extend cancer patients' period of life after the diagnosis and treatment process, to make them conscious of risky lifestyle and nutritional behavior so that they can maintain a high quality of life, and to start initiatives in this direction that would ensure changes in behavior.

• Journal of the Korean Society of Costume
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• v.54 no.4
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• pp.1-14
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• 2004

This study suggests the popular culture theory as a basic framework to find out the characteristics of contemporary fashion show meeting the popular culture, and describes that the show is the popular culture of this generation. The culture is the way of our life unifying the world at common area of human being. The popular culture is to subdivide it into the public culture that shares aesthetic taste, and to borrow each other and develop it mutually because of the collapse of dichotomous boundary with high quality culture, and to represent the people’s thought and behaviour expanding their areas. The author has examined the characteristics of popular culture of modern fashion show by four collections, that is, commercialism, mass media, political relationship and interaction, etc： Firstly, at the commercialism, the fashion show combines it with other genre organically to do mass production and sales and produces cultural consumption goods supplying a lot of sight-seeing. Secondly, at the mass media, the image of contemporary fashion show has been spread out with mass media such as fashion magazines, cable TV and Internet beyond time and space to produce advertisement effects and makes new fashion and bring democratic culture. Thirdly, at political relationship, the fashion in its peak can make a big stream of wealth, so that it plays important roles under governmental regulations in this era and governments make efforts to support and develop it. Lastly, at interaction, the fashion show shares media functions to let users participate in the program and to exchange information as a feedback to influence each other.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.301-310
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• 1999

In this paper a numerical model and two analytical models in the hydraulically connected stream-aquifer system were analyzed to compare the induced infiltration rate curves derived from each model. And we also examined the effects of anisotropy of hydraulic conductivity and the direction of the ambient ground water flow on the quantification of the induced infiltration rate. The induced infiltration rate curve determined by models is very simple and useful for estimating the induced infiltration rate since it contains only four physical variables such as the induced infiltration rate, the pumping rate, the distance between the pumping well and the stream, and the ambient ground water flow rate. Under the conditions tested in this paper the induced infiltration rate curves resulted from the Wilson's analytical model and FEWA numerical model were in good agreement, and the anisotropic ratio of hydraulic conductivity was evaluated as a physical factor which influences the behaviour of the induced infiltration rate curve. The methods and results of the paper might Icad to improve the understanding of the induced infiltration phenomenon and can be applied to the planning and disign of pumping well and the optimal determination of the induced infiltration rate and pumping rate for water quality management of the water supply wells.