• Journal of the Korean Geophysical Society
• /
• v.5 no.4
• /
• pp.321-328
• /
• 2002

Difficulties encountered in downhole S-wave (shear wave) surveys include the precise determination of shear wave travel times and determination of geophone orientation relative to the direction of polarization caused by the seismic source. In this study an S-wave enhancing and a principal component analysis method were adopted as a tool for determination of S-wave arrivals and the direction of polarization from downhole S-wave survey data. An S-wave enhancing method can almost double the amplitudes of S-waves, and the angle between direction of polarization and a geophone axis can be obtained by a principal component analysis. Once the angle is obtained data recorded by two horizontal geophones are transformed to principal axes, yielding so called scores. The scores gathered along depth are all in-phase, consequently, the accuracy of S-wave arrival picking could be remarkably improved. Applying this processing method to the field data reveals that the test site consists of a layered ground earth structure.

• Computers and Concrete
• /
• v.8 no.2
• /
• pp.193-206
• /
• 2011

The use of Carbon Fiber Reinforced Polymers (CFRP) to strengthen reinforced concrete beams under bending and shear has gained rapid growth in recent years. The performance of shear strengthened beams with externally bonded CFRP laminate or fabric strips is raising many concerns when the beam is loaded under cyclic loading. Such concerns warrant experimental, analytical and numerical investigation of such beams under cyclic loading. To date, limited investigations have been carried out to address this concern. This paper presents a numerical investigation by developing a nonlinear finite element (FE) model to study the response of a cantilever reinforced concrete T-beam strengthened in shear with side bonded CFRP fabric strips and subjected to cyclic loading. A detailed 3D nonlinear finite element model that takes into account the orthotropic nature of the polymer's fibers is developed. In order to simulate the bond between the CFRP sheets and concrete, a layer having the material properties of the adhesive epoxy resin is introduced in the model as an interface between the CFRP sheets and concrete surface. Appropriate numerical modeling strategies were used and the response envelope and the load-displacement hysteresis loops of the FE model were compared with the experimental response at all stages of the cyclic loading. It is observed that the responses of the FE beam model are in good agreement with those of the experimental test. A parametric study was conducted using the validated FE model to investigate the effect of spacing between CFRP sheets, number of CFRP layers, and fiber orientation on the overall performance of the T-beam. It is concluded that successful FE modeling provides a practical and economical tool to investigate the behavior of such strengthened beams when subjected to cyclic loading.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.12
• /
• pp.1195-1204
• /
• 2020

Tourism is not only a cultural service but also a resource consuming industry. Landscape function framework is a powerful tool to show the relationship between nature and people. This study collects 50 documents around the world to analyze the relationship between the 4 functional groups of the landscape (regulatory functions, production and supply functions, resident functions, information and entertainment functions) and the tourism industry. On that basis, we created an establishment for practical contact analysis of the goods and services of the landscape for tourism development in Moc Chau plateau, Vietnam. Research results show that tourism is an economic sector that benefits from the landscape and has a clear resource orientation. Moc Chau plateau has rich tourism resources and has the conditions to develop various types of tourism, especially cultural tourism based on community and resort tourism. The two cultural functions and the providing functions are the two most important functional groups for the tourism development of Moc Chau district, bringing the two most important tourism icons for Moc Chau, a green steppe, cool milk benevolent and also a district rich in national culture. From these conclusions, the authors give recommendations and notable points about landscapes in the tourism industry, especially in places with topography like Moc Chau.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.6
• /
• pp.365-378
• /
• 2020

The study aims to develop concepts originating through empirical research models to build superior competitiveness and optimal performance achievement. Therefore, to bridge these goals, the study addresses several indicators/items as a novelty, namely, entrepreneurship insight factors, market orientation, knowledge-sharing, innovation, managerial capability, product strategy, process and service improvement, resources capability to improve performance and increase competitiveness by empirical model direct, mediating and indirect effect. The total sample in this study is 497 eligible SMEs that partner with go-food in Makassar City. All research samples are the owner or the person in charge of the business; the data collection period is from May to December 2019. Data are collecting using a survey with 64 construct questions, summarized in seven manifest variables. The research method uses quantitative tools, with SMART-PLS as a statistical tool. This study develops sixteen hypotheses; all of the hypotheses are supported both directly, indirectly, and mediated. The study also found that the link based on CCT, RBV, and TAM Theory is the right choice of theories, as the foundation of this study was very reliable and valid. Indeed, all of the grounded methods have implications both in theory and its main application for the business in the online marketplace.

• Journal of Hospice and Palliative Care
• /
• v.17 no.3
• /
• pp.142-150
• /
• 2014

Purpose: This study was to identify the attitude of Korean HIV (Human Immunodeficiency Virus)-positive men toward death. Methods: A Q-methodology was performed with 20 HIV-positive male individuals. Participants were asked to select and answer questions among a set of 40 Q-statements using a 9-point scale. The collected data were analyzed using the PC QUANL program. Results: Participants' attitudes toward death were categorized into four types. Type I was characterized by respect for life, type II by reality orientation, type III by pain evasion and type IV religious beliefs. Conclusion: It is necessary to develop an assessment tool and an intervention program for HIV-positive individuals.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.5
• /
• pp.365-374
• /
• 2017

SAR (Synthetic Aperture Radar) is an effective tool for monitoring areas damaged by disasters. Full PolSAR (Polarimetric SAR) enhances SAR's capabilities by providing specific scattering mechanisms. Thus, full PolSAR data have been widely used to analyze the situation when disasters occur. To interpret full PolSAR data, model-based decomposition methods are frequently used due to its easy physical interpretation of PolSAR data and computational efficiency. However, these methods present problems. One of the key problems is the overestimation of the volume scattering component. To minimize the volume scattering component, the OA (Orientation Angle) compensation method is widely utilized. This paper shows that the effect of the OA compensation was analyzed over landslide affected areas. In this paper, the OA compensation is applied by using the OA estimated from the maximum relative Hellinger distance. We conducted an experiment using two full polarimetric ALOS/PALSAR (Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar)-2 data collected over Mocoa, Colombia which was seriously damaged by the 2017 Mocoa landslide. After OA compensation, the experimental results showed volume scattering power decreased, while the double-bounce and surface scattering power increased. Particularly, significant changes were noted in urban areas. In addition, after OA compensation, the separability of the double-bounce and surface scattering components are improved over the damaged building areas. Furthermore, changes in the OA can discriminate visually between the damaged building areas and undamaged areas. In conclusion, we demonstrated that the effect of OA compensation improved the influence of the double-bounce and surface scattering components, and OA changes can be useful for detecting damaged building areas.

• Journal of Welding and Joining
• /
• v.33 no.2
• /
• pp.8-13
• /
• 2015

This study was carried out to evaluate mechanical properties of the jointed Al6061/HT590 alloys by friction stir welding (FSW). FSW was conducted under the conditions with tool rotating speed of 500 RPM and traveling speed of 300 mm/min., where Ar gas was introduced to prevent the materials from corrosion during the welding process. Electron back-scattering diffraction (EBSD) was used to characterize microstructures such as grain size, misorientation angle and crystal orientation. Evolution of intermetallic compounds in Al6061 during the process were examined in terms of morphology, size and aspect ratio at three distinct zones Al base material, heat affected zone and stir zone, where transmission electron microscope (TEM) was used. It was revealed that FSW gave rise to refinement of grains as well as growth of intermetallic compounds in Al6061. The morphological changes of intermetallic compounds exerted an influence on mechanical properties, resulting in occurrence of fracture in the part of the base material instead of the jointed parts (heat affected zone and stir zone). This study systematically evaluated the microstructural evolutions during the FSW for joining Al6061 with HT590 and their effect on mechanical properties.

• The KIPS Transactions:PartD
• /
• v.14D no.1 s.111
• /
• pp.67-82
• /
• 2007

Due to the classes in object-orientation, which are too detailed and specific, their reusability can be decreased. Components, considered to be more coarse-grained compared to objects, help maintain software complexity effectively and facilitate software reuse. Furthermore, component technology becomes essential by the appearance of the new frameworks, such as MDA, SOA, etc. Consequently, it is necessary to reengineer an existing object-oriented system into a component-based system suitable to those new environments. In this paper, we propose a model-based quantitative reengineering methodology to identify components from object-oriented systems. We expand system model and process, which are defined in our prior work, more formally and precisely. A system model, constructed from object-oriented system, is used to extract and refine components in quantitative ways. We develop a supporting tool and show effectiveness of the methodology through applying it to an existing object-oriented system.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.8
• /
• pp.873-877
• /
• 2010

CAPTCHA is a security tool that prevents the automatic sign-up by a spam or a robot. This CAPTCHA usually depends on the smart readability of humans. However, the common and plain CAPTCHA with text-based system is not difficult to be solved by intelligent web-bot and machine learning tools. In this paper, we propose a new sub-image based CAPTCHA system totally different from the text based system. Our system offers a set of cropped sub-image from a whole digital picture and asks user to identify the correct orientation. Though there are some nice machine learning tools for this job, but they are useless for a cropped sub-images, which was clearly revealed by our experiment. Experiment showed that our sub-image based CAPTCHA is easy to human solver, but very hard to all kinds of machine learning or AI tools. Also our CAPTCHA is easy to be generated automatical without any human intervention.

• Tunnel and Underground Space
• /
• v.13 no.4
• /
• pp.304-315
• /
• 2003

In this paper, the DDA method with a new hydro-mechanical algorithm is used to study the effect of rock discontinuities on uplift and seepage in concrete gravity dam foundations. This paper presents an alternative method of predicting uplift and seepage at the base of concrete gravity dams. A sensitivity analysis was carried out to study the importance of several parameters on dam stability such as the orientation, spacing, and location of discontinuities. The study shows that joint water flow and adverse geological conditions could result in unusual uplift at the base of concrete gravity dams, well in excess of what is predicted with the classical linear or hi-linear pressure assumption. It is shown that, in general, the DDA program with the hydro-mechanical algorithm can be used as a practical tool in the design of gravity dams built on fractured rock masses.