• Journal of Sensor Science and Technology
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• v.11 no.3
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• pp.163-170
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• 2002

This paper proposes a $10\;{\mu}m$ thick oxide air-bridge structure which can be used as a substrate for RF circuits. The structure was fabricated by anodic reaction, complex oxidation and micromachining technology using TMAH etching. High quality films were obtained by combining low temperature thermal oxidation ($500^{\circ}C$, 1 hr at $H_2O/O_2$) and rapid thermal oxidation (RTO) process ($1050^{\circ}C$, 2 min). This structure is mechanically stable because of thick oxide layer up to $10\;{\mu}m$ and is expected to solve the problem of high dielectric loss of silicon substrate in RF region. The properties of the transmission line formed on the oxidized porous silicon (OPS) air-bridge were investigated and compared with those of the transmission line formed on the OPS layers. The insertion loss of coplanar waveguide (CPW) on OPS air-bridge was (about 2dB) lower than that of CPW on OPS layers. Also, the return loss of CPW on OPS air-bridge was less than about -20 dB at measured frequency region for 2.2 mm. Therefore, this technology is very promising for extending the use of CMOS circuitry to higher RF frequencies.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.201-206
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• 2004

This experiment was performed to evaluate the agronomic characteristics and dry matter yields of the early maturing cultivars(c.v.'Koolgrazer', '9909,' 'Ol-homil' and 'Jlee select') the medium maturing cultivar(c.v. 'Homil 22') and late maturing cultivars(c.v. 'Danko', 'Kior', 'Amilo' and 'Spooner'.) Seeds were sown on October 3, 2002 and October 8, 2003, respectively at the Livestock Experiment Farm of Keimyung College, Seongju, Kyeongbuk Province. Forage rye was harvested on April 22, 2003 and April 23, 2004, respectively. The height of early maturing cultivars were higher than that of late maturing cultivars at the harvest. Fifty percent heading date of the early maturing cultivar was on April 14 and that of late maturing cultivars were on April 24. In the first year, dry matter(DM) yield of 'Jlee select' was significantly the highest in among all cultivars(p < 0.05). DM yield of early maturing cultivars were higher than that of medium and later maturing cultivars. In the second year, DM yield of '9909' was significantly the highest in among all cultivars(p < 0.05). The early maturing cultivar of 'Koolgrazer' and 'Ol-homil' were similar and 'Jlee select' was low, late maturing cultivar of 'Danko', 'Kior', 'Amilo' and 'Spooner' were lower than early maturing cultivar. According to the results obtained from the study, it is suggested that the early maturing cultivar would be recommendable for fall sown rye for double cropping forage production.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.204-211
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• 2006

This study investigated the effect of salt and glucono-${\delta}$-lactone (GdL) on the cold-set binding of restructured pork washed and pressurized at 200 MPa. Binding strength, PH, water holding capacity (WHC) and color were determined. NaCl improved pH, WHC and binding strength. GdL also increased binding strength while decreased WHC and pH significantly (p<0.05). However, low GdL level combined with NaCl showed high pH and WHC, compared to control. In color, NaCl decreased $L^*$-value with increasing $a^*$-value significantly (p<0.05). In contrast to NaCl, GdL increased $L^*$-value and decreased $a^*$-value. GdL tended to decrease $b^*$-value and significant differences were found when GdL was added above 1%. Pearson's correlation coefficients presented that NaCl had a significant effect on binding strength (0.6632) and lightness (-0.7330) while GdL had a significant correlation with all parameters barring binding strength. The results indicated that under washing and pressure treatments, GdL had a potential effect on cold-set binding with reducing NaCl concentration, especially when low GdL concentration combined with NaCl was added.

• Informatization Policy
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• v.24 no.1
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• pp.3-29
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• 2017

The purpose of this research is to understand immersive media such as virtual reality, augmented reality, mixed reality, 360-degree videos etc. from the perspective of user-based approach. 3D videos were once expected as the next-generation industry, but soon it further evolved into UHD and are now followed by immersive media represented by virtual reality. As the virtual reality plays an important role, the current research tries to bring up implications that can be applied to the industrial field along with academic understanding through six theoretical approaches related to virtual reality such as media richness, interactivity, presence, body-ownership, user experience, and visual perception. These six theories were used in immersive media studies such as 3D videos. Media richness and interactivity are the main factors forming positive or negative attitude, presence explains why users are immersed, user experience accounts for total psychological reaction, and visual perception explains how complex the experience of seeing is. Especially, although there is less media research applied, the body-ownership is likely to be not only used in virtual reality research, but immersive media research. The user-based theories related to virtual reality will provide various implications for immersive media researchers as well as hardware and content creators of virtual reality.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.28-34
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• 2017

This study was carried out to investigate growth characteristics of woody plants that are widely used indoors in accordance with irrigation frequency and to find the optimum irrigation conditions for plants that help to improve the indoor environment. Four woody plants used in this study included Ardisia pusilla, Clusia rosea, Fatsia japonica, and Ficus elastica. They were planted in pots with a diameter of 10cm and cultivated in three different irrigation frequencies: two times per week, one time per week, and one time per two weeks. After 120 days, they were measured by plant height, fresh weight, dry weight, SPAD value, leaf color, leaf water potential, chlorophyll fluorescence (Fv/Fm), and photosynthetic rate. The average soil moisture content was $48.8{\pm}2.1%$ in two times per week, $25.2{\pm}4.4%$ in one time per week, and $10.3{\pm}2.4%$ in one time per two weeks. For A. pusilla, leaf water potential was higher, and Fv/Fm value was 0.731 in two times per week irrigation, showing more wetness. For A. pusilla, F. japonica and F. elastica photosynthetic rate was significantly lower in one time per two weeks irrigation, appearing to be more sensitive to drying than C. rosea. When irrigated one time per week, with the soil's volume average moisture content of 25%, all four woody plants used in this experiment proved to grow smooth. Thus, it was determined to be good for use in indoor landscaping.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.6
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• pp.23-36
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• 2005

PLLs have been widely used for many applications including communication systems. This paper presents a VCO with an improved negative skewed delay scheme and a PLL using this VCO. The proposed VCO and PLL are intended for replacing traditional LC oscillators and PLLs used in communication systems and other applications. The circuit designs of the VCO and PLL are based on 0.18um CMOS technology with 1.8V supply voltage. The proposed VCO employs subfeedback loops using pass-transistors and needs two opposite control voltages for the pass transistors. The subfeedback loops speed up oscillation depending on the control voltages and thus provide a high oscillation frequency. The two voltage controls have opposite frequency gain characteristics and result in low phase-noise. The 7-stage VCO in 0.18um CMOS technology operates from $3.2GHz\~6.3GHz$ with phase noise of about -128.8 dBc/Hz at 1MHz frequency onset. For 1.8V supply voltage, the current consumption is about 3.8mA. The proposed PLL has dual loop-filters for the proposed VCO. The PLL is operated at 5GHz with 1.8V supply voltage. These results indicate that the proposed VCO can be used for radio frequency operations replacing LC oscillators. The circuits have been designed and simulated using 0.18um TSMC library.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.17-36
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• 2013

In this paper, the empirical relations of skin friction and end bearing resistance with the results of site investigation in soft rock are proposed through the analysis of bi-directional pile load tests of rock socketed drilled shafts performed at large offshore bridge foundations and high-rise building projects (13 test piles in 4 projects). The site investigation and drilling for bi-directional pile load tests were performed at the centers of test piles, and f-w curves for skin friction and q-w curves for end bearing were plotted based on load-transfer measurements. From the above curves, the empirical relations of skin friction and end bearing resistance with the results of site investigation depending on the mobilized displacement are determined by multiple regression analysis and compared with previous studies. Since the f-w and q-w curves of rock-socketed piles in Korea show hardening behavior according to mobilized displacement, the developed empirical relations by the mobilized displacement are more reasonable than those of previous studies which could not consider the mobilized displacement and suggested the ultimate capacity with unconfined compressive strength only. Particularly, the developed equations correlated with unconfined compressive strength show the best correlations among the equations correlated with other parameters.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.163-169
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• 2020

The purpose of this study is to find out whether the environment is based on the Color Universal Design (CUD, CUD Recommended Color Set Guidebook), which is located in the area with the highest proportion of elderly people in the city of Busan in Korea. Five nearby parks in the walking district of Busan were selected to measure the environmental color with a spectrophotometer(Minolta CM-2600d) and web color search. The range of the color survey was limited to the pavement; public facilities(sign, benches, restroom), and exercise&sports facilities. The results of the study are as follows. Overall, the Y color group was dominant, with similar color usage and intensity, and similar levels of saturation. This was analyzed based on the Color Universal Design theory, suggesting that the visual characteristics of the elderly were not taken into account, and the Neighborhood Park located in Busan was found to lack the environmental color of consideration for the visual characteristics. In addition, this study could act as a basic study that can be applied to social and environmental colors that reflect the color perception and cognitive characteristics of the elderly.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.255-267
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• 2017

The purpose of this research is to secure the foundational data for analyzing the mediating role of social capital from the influences of the feeling of self-efficacy of the elderly on the preparations for the old age. The subjects of this study were 518 questionnaires collected from March 20 to April 1, 2016 for the elderly over 60 years old who were living in S city. Regarding the data, the SPSS 20.0 and the AMOS 20.0 were used. And, the results of this research were the following: First, if we take a look at the influences of the feeling of self-efficacy on social capital, the feeling of self-efficacy has the positive influences. And, second, the influences of the feeling of self-efficacy on the preparations for the old age, also, are positive. Third, the influences of the social capital on the preparations for the old age, too, are positive. As such, we can find out that both the direct and indirect effects were shown. Lastly, we can find out that the feeling of self-efficacy has the partial mediating effects on the social capital and the preparations for the old age. Consequently, although the feeling of self-efficacy is insufficient with regard to the economic preparations, we can positively find out that it was able to effectively derive the satisfaction in life by utilizing the social capital. In preparation for the super-aged society, the improvements and the expansions of the social programs and the services resulting from them are needed through the establishment of a foundation regarding the life-periodical, social participation, the establishment of a socially-shared system that can be continued, and the policy of strengthening the social capital.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.395-405
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• 2005

This paper summarizes the test results of the flexible-stiff mixed system for the effective use of high-strength steel. Steel with a high degree of strength and performance is being increasingly required as buildings get larger and taller. High-strength steels cannot be used for many applications, though, because they have a number of defects. For instance, they have a high yield ratio, a small strain in maximum stress, and equal Young's modulus compared to mild steels. A new structural system is needed to effectively use high-strength steels with some defects. This paper proposes the flexible-stiff mixed system for the effective use of high-strength steels with high yield ratios. The possibility of using the system is discussed through the test of flexible-stiff mixed columns with high-strength steels. The main variable of the specimens is the yield displacement ratio, including both the force ratio and the stiffness ratio. The proper yield displacement ratio is proposed by adopting the flexible-stiff mixed system. The test results showed that the proposed flexible-stiff mixed system has a high capacity for energy absorption and the highest capacity for energy absorption when the yield displacement ratio of the flexible element to the stiff element ranges from 2.7 to 3.3.