• Journal of Information Technology Applications and Management
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• v.25 no.2
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• pp.53-72
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• 2018

This empirical study explored characteristics that affect the usefulness of online reviews, in the China e-commerce platform, and implemented multiple regressions to find factors that significantly influence on product sales, ultimately. Till now, prior studies have continuously revealed what factor affects usefulness of online review or product sales, only in respective terms. The point of our study is that we built two-level regression models, thereby being able to comprehensively analyze these two different targets. Before plunging into running regressions, we carefully collected 192,764 online review data for 200 products extracted from the Jingdong, the second biggest e-commerce platform in China. Also, we gathered "review sentimental scores" variable from each review and used that one as a core variable in our regression model, thus we were able to implement both quantitative and qualitative research. The evidences from the two-level regression models showed that the extent to which a product is experience good positively affects both usefulness of a review and product sales, again the usefulness of a review contributes to product sales in sequence. Also, the property of experience good has interaction effect on both for two-level regression models. Our main findings highlight the importance of role of online review to business performance of e-commerce firms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.965-968
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• 2005

According to the rapid development of IT technologies, between different technologies and weakness of entry barriers, standardization for interoperability and intercompatibility is being recognized as a core strategy for preoccupation of global IT market and strengthening of national competitive power. Recently IPR(Intellectual property Rights) including patents is considered indispensably in international standardization. Also advanced countries strengthen their positions through preemption of global IT market by linking their IPR with international standardization. Therefore relationship between IPR and standardization is being changed to mutually complementary from mutually exclusive. In this paper, we will examine ITU-T's IPR policy and related discussion trends in ITU-T and try to find national policy for IPR related issues.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2633-2640
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• 2009

We design a small-area, low-power, and high-speed EEPROM for touch screen controller IC. As a small-area EEPROM design, a SSTC (side-wall selective transistor) cell is proposed, and high-voltage switching circuits repeated in the EEPROM core circuit are optimized. A digital data-bus sensing amplifier circuit is proposed as a low-power technology. For high speed, the distributed data-bus scheme is applied, and the driving voltage for both the EEPROM cell and the high-voltage switching circuits uses VDDP (=3.3V) which is higher than the logic voltage, VDD (=1.8V), using a dual power supply. The layout size of the designed 128-KBit EEPROMIP is $662.31{\mu}m{\times}1314.89{\mu}m$.

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.148-153
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• 2010

Transparent conducting films having a hybrid structure of GZO/Metal/GZO were prepared on glass substrates by sequential deposition using DC magnetron sputtering. Silver, copper, aluminum and zinc thin films were used as the intermediate metal layers in the hybrid structure. The electrical and optical properties of hybrid transparent conducting films were investigated with varying the thickness of metal layer or GZO layers. With increasing the metal thickness, hybrid films showed a noticeable improvement of the electrical conductivity, which is mainly dependent on the electrical property of the metal layer. GZO(40 nm)/Ag(10 nm)/GZO(40 nm) film exhibits a resistivity of $5.2{\times}10^{-5}{\Omega}{\cdot}cm$ with an optical transmittance of 82.8%. For the films with Zn interlayer, only marginal reduction in the resistivity was observed. Furthermore, unlike other metals, hybrid films with Zn interlayer showed a decrease in the resistivity with increasing the GZO thickness. The optimal thickness of GZO layer for anti-reflection effect at a given thickness of metal (10 nm) was found to be critically dependent on the refractive index of the metal. In addition, x-ray diffraction analysis showed that the insertion of Ag layer resulted in the improvement of crystallinity of GZO films, which is beneficial for the electrical and optical properties of hybrid-type transparent conducting films.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.4
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• pp.47-58
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• 2020

This study was done to evaluate resources distributed around the Nakdong-Jeongmaek which is the eastern ridge line of the Nakdong-river basin with 437km in length. Here we found and/or searched for thousands of resources within each of 210 villages around the ridge, which were divided into six categories including landscape, natural park, protected area, history, tourism and biodiversity. An inventory was also created using an attribute table in a shape file for identifying the spatial location and property for every resource existing in each village. Each of fields for six-typed resources has 210 records representing each village and resources within it. If a resource exists in a village, '1' is assigned for its existence in its corresponding record. Otherwise, '0' is assigned for its non-existence in the record. The number of '1' on six records for a village is meaning the number of resources contained within a village, which can be a barometer to decide the properties of each village. In this study, we found five core villages containing all kind of resources in it, while 52 villages were found having only a single type of resources within it. The other villages were known to have multiple resources like having two or more ones.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.75-82
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• 2014

This study investigated the physical properties of aramid/nylon ATY and aramid ATY for protective garments according to the aramid and nylon characteristics fed on the core and effect components of air jet texturing equipment. Tenacity decrease of aramid ATY was much more higher than that of nylon ATY because of slick of aramid filament surface. Tenacity of aramid/nylon ATY was most affected by the tenacity of nylon on the effect component of ATY. Breaking strain of nylon ATY was two times higher than that of nylon before air jet texturing, then, in case of aramid ATY and aramid/nylon ATY, were 5.9-6.7 times higher than those before air jet texturing. Initial modulus decrease of aramid ATY showed 86.5% of initial modulus of aramid before air jet texturing, then aramid/nylon hibrid ATY showed arithmetic average value of initial modulus of aramid and nylon ATY. Wet and dry thermal shrinkages of aramid/nylon hybrid ATY were dominated by those of nylon filament on the effect component of ATY.

• Journal of Educational Research in Mathematics
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• v.19 no.4
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• pp.479-491
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• 2009

This paper researches the possibility of introducing Descartes' theorem to mathematically gifted students. Not only is Descartes' theorem logically equivalent to Euler's theorem but is hierarchically connected with Gauss-Bonnet theorem which is the core concept on differential geometry. It is possible to teach mathematically gifted students Descartes' theorem by generalizing mathematical property in solid geometry through analogical reasoning, that is, so in a polyhedrons the sum of the deficient angles is $720^\circ$ as in an polygon the sum of the exterior angles is $360^\circ$. This study introduces an alternative method of instruction that we enable mathematically gifted students to reinvent Descartes' theorem through analogical reasoning instead of deductive reasoning.

• Journal of Korea Foundry Society
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• v.40 no.4
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• pp.118-127
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• 2020

Microstructural evolution during a heat treatment and high-temperature tensile properties have been investigated in conventionally cast CM247LC. In as-cast specimens, MC carbides with high amounts of Ta, Ti, Hf, and W were found to exist in the interdendritic regions, and γ' was observed in the form of cubes and octocubes prior to decomposition into cubes. In the heat-treated condition, some portion of eutectic γ-γ' remained, and uniform cubic γ' was observed in both interdendritic regions and dendrite core. Three types of carbides with different stoichiometries and compositions were found at the grain boundaries. MC carbides with high Hf contents were observed in the vicinity of eutectic γ-γ'. The highest tensile strength value was found at 750℃, whereas the greatest ductility appeared at 649℃. The effect of the temperature on the tensile properties was closely related to the dislocation structure. With increase in the test temperature, the density of dislocations inside γ' decreased, whereas that in the γ matrix increased. Stacking faults generated in γ' at 750℃ had a strengthening effect, whereas thermally activated dislocation motion at a high temperature was considered to have the opposite effect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.518-521
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• 2005

We performed the mechanical test for obtaining properties of femoral head. Tested sample was male and 35 years old. We measured bone mineral density by dual X-ray absorption method(DEXA). Results of DEXA, he has normal condition of bone density. His BMD $1.159g/cm^2$ and T-Score is 1.6. Tested femurs were harvested by surgical method from donated cadaver. We made 9 specimens in femoral head, 8 specimens in neck used by diamond core drill. Then we performed compressive test in saline solution at $38^{\circ}C$. We obtained results that elastic modulus of femoral head was 0.439GPa, neck was 0.459GPa. Compressive strength of femoral head was 7.441 MPa, neck was 7.095MPa. There was no significant difference of mechanical properties between left and right femoral head & neck. Invested local properties of femoral head have more strength superior and anterior side, femoral neck has more strength in superior and inferior side but other side except for superior has more weakness along the lateral side.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.33-41
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• 2006

Nowadays in Korea, KS F 2271(Testing method for incombustibility of internal finish material and element of buildings) has been using for the evaluation of fire safety performance of sandwich panels. The test method in Japan and in Korea was based on the same way. When the Japanese standard building code was revised in 2000, the test method in the ISO 5660-1 was adopted for the test method for combustion performance of internal finishing materials and elements of buildings. According to this, the revision version of draft substituting the test method in the KS F 2271 for one in the ISO 5660-1(Cone Calorimeter method) is informed in Korea. In this study, combustion properties of sandwich panels were tested using the cone calorimeter method. Ignition time, peak heat release rate and total heat released of four sandwich panels and four core materials (thermal insulation material), which are widely used in Korea, were tested. Test results were analyzed for each specimen. Finally, test results were classified by Japanese standard building code and Canadian NBC revised.