• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.105-118
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• 2008

Shotcrete is one of the main support materials in tunnelling. Its bonding state on excavated rock surfaces controls the safety of the tunnel: De-bonding of shotcrete from an excavated surface decreases the safety of the tunnel. Meanwhile, the bonding state of shotcrete is affected by blasting during excavation at tunnel face as well as bench cut. Generally, the bonding state of shotcrete can be classified as void, de-bonded, or fully bonded. In this study, the state of the back-surface of shotcrete is investigated using impact-echo (IE) techniques. Numerical simulation of IE technique is performed with ABAQUS. Signals obtained from the IE simulations were analyzed at time, frequency, and time-frequency domains, respectively. Using an integrated active signal processing technique coupled with a Short-Time Fourier Transform (STFT) analysis, the bonding state of the shotcrete can be evaluated accurately. As the bonding state worsens, the amplitude of the first peak past the maximum amplitude in the time domain waveform and the maximum energy of the autospectral density are increasing. The resonance frequency becomes detectable and calculable and the contour in time-frequency domain has a long tail parallel to the time axis. Signal characteristics with respect to ground condition were obtained in case of fully bonded condition. As the ground condition worsens, the length of a long tail parallel to the time axis is lengthened and the contour is located in low frequency range under 10 kHz.

• Information Systems Review
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• v.14 no.1
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• pp.67-84
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• 2012

Recent increases in uncertainty and speed of market change are driving the adoption of new intelligent mobile office systems. Organizational information systems paradigm suggests that a right match between organizational characteristics and the use of technology is critical in producing desired results. Following such perspective this study developed the mobile office system case of Seoul Metropolitan Railway Transit(SMRT) in Korea. SMRT developed the mobile task-supporting environment that help the management of subway lines real-time without the restriction of time and space. They named the system as ST&F(SMRT Talk and Flash). They decided to develop the application systems in-houses they did not want to be overly dependent on external services in future changes and developments of the system. The new practice reduced the time for moving back and forth to 10% of their working time from previous 20%. The time used for paper works and administration chore also reduce to 10% of their working time from previous 30% on the average. The employees could use 80% of their time to concentrate on the completion of assigned task. The effects of this improvement resulted in the heightened efficiency of the use of human resources and the heightened level of railway safety. The case of SMRT shows that the mobile office system can be applied and extended to various business areas such as facility management and maintenance beyond such typical uses as sales and marketing support. Also, The result of case study will be a useful guideline on the construction and using of mobile office system.

• Conservation Science in Museum
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• v.15
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• pp.96-121
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• 2014

Portrait of Sim Huisu is a seventeenth-century Joseon portrait of a meritorious vassal. The National Museum of Korea currently owns two portraits of Sim Huisu, which are the eldest son's family and by the eldest grandson of the family's second eldest son. Both were donated in 1980. Portraits were still in its original mounting, but the supporting silk had been damaged and stained in a flood. Conservation treatment was undertaken to restore the original style, and scientific analysis, such as, X-ray, XRD, XRF and Graff "C" stain, was conducted to study the materials and painting techniques. The support silk was found to be refined fibroin and a plain weave consisting of two weft threads and one warp thread. The lining papers were found to be bamboo fiber paper of first layer in China and Korean traditional mulberry paper in second. Various pigments were identified in the painting, including white lead, cinnabar, atacamite, ink stick, azurite, silver, and gold. The study also confirmed the use of the back painting, with colors such as white ^{White Lead}, green ^Atacamite, orange ^Minium, black ^{Ink Stick}, and yellow ^Dye. Also, it was found that stick ink or dye was used with white lead.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.49-58
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• 2008

The purpose of this study was to identify effects of walking speed and a cognitive task during treadmill walking on gait variability. Experiments consisted of 5 different walking speeds(80%, 90%, 100%, 110% and 120% of preferred walking speed) with/without a cognitive task. 3D motion analysis system was used to measure subject's kinematic data. Temporal/spatial variables were selected for this study; stride time, stance time, swing time, step time, double support time, stride length, step length and step width. Two parameters were used to compare stride-to-stride variability with/without cognitive task. One is the coefficient of variance which is used to describe the amount of variability. The other is the detrended fluctuation analysis which is used to infer self-similarity from fluctuation of aspects. Results showed that cognitive task may influence stride-to-stride variability during treadmill walking. Further study is necessary to clarify this result.

• Archives of design research
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• v.20 no.3 s.71
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• pp.163-178
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• 2007

The importance of brands as well as the consumers' emotional & cultural desire have increased. In the meantime, the companies have made efforts to create their positive brand images through the support of Mecenat using culture or social return. In addition, they made ceaseless efforts to provide consumers with a cultural space by building up brand service areas as part of their purpose. However, the rapidly increasing brand service spaces have not really appealed to consumers. In order to become a competitive and powerful brand in the severe brand market, it is necessary to enhance the brand image and to let the brand be considered as a culture and the lifestyle of consumers. In order to do so, the companies have to establish their market-driving strategies by creating new products or new market. To do so, it is important for them to figure out consumers' inner desire through the touch point with consumers. This study attempted to suggest a method of using a corporate museum as a space that could meet all of the said elements at a time. Through the route of a corporate museum, the companies would be able to study their future directions by looking back their history and they could be reborn as culture brands. Therefore, this study suggested that the corporate museum could be a space for culture and education as well as a brand space and could play a positive role in the companies; in this process, the study could grope for consumers' inner desire with its touch point where companies and consumers would meet and its utilization of brand market-driving strategy as a test marketing strategy observing consumers' responses.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.71-82
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• 2003

In this paper, I proposed a classifier of liver cirrhotic step using T1-weighted MRI(magnetic resonance imaging) and hierarchical neural network. The data sets for classification of each stage, which were normal, 1type, 2type and 3type, were obtained in Pusan National University Hospital from June 2001 to december 2001. And the number of data was 46. We extracted liver region and nodule region from T1-weighted MR liver image. Then objective interpretation classifier of liver cirrhotic steps in T1-weighted MR liver images. Liver cirrhosis classifier implemented using hierarchical neural network which gray-level analysis and texture feature descriptors to distinguish normal liver and 3 types of liver cirrhosis. Then proposed Neural network classifier teamed through error back-propagation algorithm. A classifying result shows that recognition rate of normal is 100%, 1type is 82.3%, 2type is 86.7%, 3type is 83.7%. The recognition ratio very high, when compared between the result of obtained quantified data to that of doctors decision data and neural network classifier value. If enough data is offered and other parameter is considered, this paper according to we expected that neural network as well as human experts and could be useful as clinical decision support tool for liver cirrhosis patients.

• Archives of design research
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• v.17 no.2
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• pp.351-362
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• 2004

Generally, they respond to a phenomenon, with their any way, which they have looked at in their surroundings, and also put into their action successively and variously according as what it is. A person who has not so much problems in experiential education added to mental and physical ability prefers controlling his manner by himself as seeing, listening and feeling to being cured it by other physical support. Meanwhile, even though there are tools that we use conveniently in everyday life, it is sometimes required that user is able to control his action by himself with a certain interactive function to deal with a accidental situation. For example, in the home, when they were cooking, washing dishes and taking a bath they would not often control their minds on how to act about flowing water through the faucet going back and forth between saving and easygoing. By reasons of those statements, the project has been studied to propose the new conceptual faucet which digital technology is applied to, for recognizing the volume of water flowed through water pipe as counting it with built-in flow meter, and then saving water as controling the water-flow with faucet lever. It means that homemakers can observe the flow rate of water from the faucet placed in front of the sink in kitchen and control it right away for saving water. For studying this project, the kinds and features of the various flow-meters that measure the volume of water-flow were researched and analyzed for taking a reasonable type to the new ideal faucet. According to this analyzing, turbine-flow-meter was selected as appropriate form for the digital display-built-in faucet that would be presented in this project. As the next step, the basic structure was created for developing a new conceptual faucet. Finally two models have been presented through several steps for making the suitable shape to the new style faucet.

• The Journal of Internal Korean Medicine
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• v.26 no.4
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• pp.806-819
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• 2005

Objective : The purpose of this study is to investigate clinical characteristics and remedial value oriental medical therapy for sufferers of severe headache. Methods : On the authority of DongEuiBoCam, patients were classified into three groups: migraine, qi-syncope headache and phlegm-headache. All patients wert treated with acupuncture therapy and herb medicines. After that inquiry was made into the extent of improvement of headache. Results : 1. In accordance with the statistics, 56 cases(50.5%) had phlegm-syncope headache, 28 cases(25.2%) had qi-syncope headache and 27 cases(24.3%) had migraine. 2. The ratio between males and females was about 1:4. Most patients were in their forties. 3. 12 cases(31.6%) with migraine had pain only on the right side of the head, 20 cases(26.3%) with phlegm-syncope and 17 cases(45.6%) with qi-syncope headache suffered from the frontal lobe headache. 4. 8 cases(29.6%) with migraine had been suffering for a week or less, 12 cases(21.4%) with phlegm-syncope headache had been suffering for over six months and under one year and 6 cases(21.4%) with qi-syncupe headache had suffered over one year and under five. 5. Overwork and stress was deemed the main cause of migraine. Phlegm-syncope headache was also attributed to stress and tense situations. Qi-syncope headache was believed to be variously caused by traffic accident, noise, blood pressure and other reasons. 6. 46 cases(30%) felt dull headache and 32 cases(20.9%) felt dizzy. The common associated symptoms of migraine and qi-syncope headache included back, neck and shoulder pain and other pains. Dizziness was an especially prevalent symptom of phlegm-syncope headache. 7. After the oriental medical therapy, 12 cases(10.8%) almost entirely recovered, 50 cases(45%) were in about half as much pain, 45 cases(40.5%) improved little and 4 cases(3.6%) felt no improvement. Conclusions : The results support a role for oriental medical therapy in treatment of headache.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.361-380
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• 2002

The purposes of this study were to a analysis of friction relation between tennis outsole and tennis playing surfaces. Tennis footwear is an important component of tennis game equipment. It can support or damage players performance and comfort. Most importantly athletic shoes protect the foot preventing abrasions and injuries. Footwear stability in court sports like tennis is incredibly important since it is estimated that as many as 45% of all lower extremity injuries occur in the foot and ankle. The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. The friction force opposes the motion of the object. Friction results when two surfaces are pressed together closely, causing attractive intermolecular forces between the molecules of the two different surfaces. The outsole provides traction and reduces wear on the midsole. Today's outsoles address sport specific movements (running versus pivoting) and playing surface types. Different areas of the outsole are designed for the distinct frictional needs of specific movements. Traction created by the friction between the outsole and the surface allows the shoe to grip the surface. As surfaces, conditions and player motion change, traction may need to vary. An athletic shoe needs to grip well when running but not when pivoting. Laboratory tests have demonstrated force reductions compared to impact on concrete. There is a correlation between pain, injury and surface hardness. These are a variety of traction patterns on the soles of athletic shoes. Traction like any other shoe characteristic must be commensurate and balanced with the sport. The equal and opposite force does not necessarily travel back up your leg. The surface itself absorbs a portion of the force converting it to other forms of energy. Subsequently, tennis court surfaces are rated not only for pace but also for the percentage of force reduction.

• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.3-13
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• 2001

It has been known that nonlinear characteristics of sorption affect the transport behavior of water soluble pollutants in soils. However detailed experimental studies have not been performed to verify the effect of non-linearity of adsorption isotherm on transport of chemicals in porous media. In this research, the distortion of breakthrough curves of a cationic surfactant (cetylpyridinium chloride, CPC) in a engineered stainless steel column packed with glass beads were investigated. Glass beads with about 110 $\mu\textrm{m}$diameter coated with a thin n-decane film were used as the media providing the sorption surface for CPC. The CPC adsorption isotherm on the surface of n-decane from aqueous solution was a typical Langmuir type. The breakthrough curve of CPC using step Input showed a late breakthrough on the front side and early breakthrough on the back side accordance to the shape of the isotherm. The retardation factor of CPC was found to be a strong function of the input concentration, which also a manifestation of the non-linearity of the isotherm. The retardation factors for the CPC with step input agreed with those of pulse input that the maximum concentrations are controlled to be the same as the step input concentrations. This results support the validity of the unproven field practices of using hydrogeotracers with non-linear adsorption isotherms to determine the hydrogeological parameters, e.g., NAPL saturation, air-water or NAPL-water interfacial areas.