• Journal of the military operations research society of Korea
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• v.29 no.1
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• pp.88-111
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• 2003

This paper is to suggest strategic options for improving the export performance of the plant and construction industry. The overall objective of this study is to explore the feasibility of a sustained export performance in the plant and overseas construction industry by an analysis of its international competitiveness and technological competence. The empirical work of this study relates to a chosen sample of Korean and non-Korean firms in the plant and construction industry sector. Primary data was collected through a comprehensive questionnaire survey administered to plant and construction firms in twelve countries, including Korea. The actual number of firms for which full information at a sufficient level of disaggregation was obtained was 62, a response rate of 44.6％. Of these, 42 firms were drawn from Korean plant and construction firms and the remaining 20 firms from 11 other countries. The structure of responding firms by industry shows a total of 29 plant exporters and 33 construction firms. Data analysis was carried out using SPSS statistical technique such as Multiple Regression in order to examine the linear relationship among variables. The findings of the study indicate that export success and failure in plant and construction export markets is determined by firm size and by various qualitative variables. The high export volume (export success) of Plant and construction exporters is more strongly influenced by mutual economic cooperation and number of employees than by sales volume and competent knowledge of the plant and construction markets. It was also found that weak political and diplomatic relation between countries, low sales volume and lack of bid experience have an adverse effect and represent serious barriers to exports.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.102-107
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• 1984

This study was undertaken to know the possibility of in vitro propagation of Stevia through axillary bud culture and the results indicated that: (1) Addition of NAA (0.01-0.05 mg/l) alone on Murashige-Skoog basal medium promoted shoot differentiation and growth rate. And also additional of kinetin of 0.5-1.0 mg/1 alone showed the same trend as that of NAA: (2) Addition of both NAA (0.01-0.05 mg/l) and kinetin (0.5-1.0mg/l) to MS medium promoted better shoot formation. (3) Shoot differentiation and growth were better on the full salt strength of MS medium (1X MS) than that of half strength ( $\frac{1}{2}$MS), while their effects were reversed for root differentiation

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4398-4417
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• 2017

Multi-user Multiple-Input and Multiple-Output (MU-MIMO) has potential for prominently enhancing the capacity of wireless network by simultaneously transmitting to multiple users. User selection is an unavoidable problem which bottlenecks the gain of MU-MIMO to a great extent. Major state-of-the-art works are focusing on improving network throughput by using Channel State Information (CSI), however, the overhead of CSI feedback becomes unacceptable when the number of users is large. Some work does well in balancing tradeoff between complexity and achievable throughput but is lack of consideration of fairness. Current works universally ignore the rational utilizing of time resources, which may lead the improvements of network throughput to a standstill. In this paper, we propose TOUSE, a scalable and fair user selection scheme for MU-MIMO. The core design is dynamic-time-warping-based user selection mechanism for downlink MU-MIMO, which could make full use of concurrent transmitting time. TOUSE also presents a novel data-rate estimation method without any CSI feedback, providing supports for user selections. Simulation result shows that TOUSE significantly outperforms traditional contention-based user selection schemes in both throughput and fairness in an indoor condition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.89-96
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• 2001

Carbohydrate and soluble protein reserves and regrowth characteristics in response to cutting height were investigated over four regrowth cycles of turf-type perennial ryegrass(Lolium perenne L. cv. preludeII). When the plants were at the full-vegetative stage (twelve weeks-old), three sequential defoliations at 3, 6 and 9 cm above the root base were imposed at 2-week intervals. Shoot dry weight in all three treatments continuously decreased with progressing regrowth cycle and the decreasing rate was higher as cutting height was lowered. TNC (total non-structural carbohydrate) in stubble at the end of the fourth regrowth cycle in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 27%, respectively, comparing the initial content. TNC in roots also largely decreased with similar pattern in response to cutting height, whereas the absolute amount was much less compared to stubble. Soluble protein in stubble in 3, 6 and 9 cm cutting height decreased by 98%, 82% and 57%, respectively, at the end of fourth regrowth. A significant correlations between TNC (r=0.906) or protein (r=0.879) at the fourth defoliation and dry weight of regrowing shoots at the end of fourth regrowth were observed. these results indicated that cutting height closely influences the levels of organic reserves available for new growth, and that the levels of reserves might provide a useful tool as a determinant for regrowth dynamics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2100-2112
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• 2011

An orthogonal code hopping multiplexing (OCHM) technique has been proposed for accommodating a large number of users with low channel activities than the number of orthogonal codewords through statistical multiplexing in downlink cellular systems. In this paper, a multiple input multiple output (MIMO) antenna based OCHM system is proposed to improve the performance. Each modulated symbol is repeated N times and the N repeated symbols are transmitted simultaneously using N transmit antennas. Through repetitions, the effect of perforations that the OCHM system experiences is decentralized among the repeated symbols and the full perforation probability is significantly reduced. Each receiver detect the transmitted signal using its pre-assigned code hopping pattern. Simulation results show that the proposed scheme saves the required energy for a given frame error rate (FER).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.11
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• pp.963-970
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• 2015

In this study, the pressurization characteristics of the small piezoelectric hydraulic pump for a brake system has been analyzed through modeling the full hydraulic pump components; the pump chamber, check valve, pump load, pump drive controller etc. To analyze the pressurization characteristics, the process of charging pressure in the chamber with stacked-layer piezoelectric actuator were firstly modeled. Secondly, the flow coefficient of the check valve in terms of valve opening has been calculated after computational fluid dynamics analysis, such as the pressure distribution around check valve and the flow rate, was conducted. Also the pump driving controller, which controls the input voltage to the actuator, was designed to make the load pressure follow the input pressure command. The simulation results find that it takes about 0.03ms to reach the operating load pressure required for the braking system. The simulation result was also verified through comparison to the result of the pump performance test.

• Health Policy and Management
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• v.9 no.4
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• pp.15-40
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• 1999

To assess the university health service organization(UHSO) and its school health programs a questionnaire survey for all of 186 four-year colleges in Korea was conducted from December 1. 1998 to March 31. 1999. The response rate was 91.9 percent(171 universities). The UHSO was established in 116 universities(67.8%L The most common name of UHSO. used in 61 universities(52.6%). was school health center. Only 45(38.8%) of the 116 universities surveyed had a committee to support and run the UHSO. The percentage of universities that had committee was higher in national universities and those with a large number of students. The average number of staff working in the UHSO was 3.5; 4.6 in national universities; and 7.1 in universities with more than 15.000 students. There were 43 universities(37.1%) which had a part-time physician and 104 universities (89. 7%) had full-time nurses. Only 4 universities(3.4%) had a independent facility for the UHSO while most of UHSO were housed in other building. The UHSO had an independent budget in 86 universities(74.1%). The average budget per university was 46.890.000 won: private universities had more budget with 59.170.000 won on average than national universities with 36.990.000 won. The average budget allocated per student was 4.362 won. A regular physical examination was performed in 72 universities(62.1%). The percentage of university that performed regular physical examination was higher in private universities than in national universities. Health counseling was performed in 113 universities(97.4%) and vaccinations in 87 universities(75.0%). Medical care services were performed in 87 universities(75.0%). and the private universities and those with over 10.000 students provided the student with more services. Environmental sanitation was executed in 73 universities(62.9%) and health education was conducted in 68 universities(58.6%)' The school health management activities were promoted in 104 universities(89.7%) out of 116 universities with UHSO. Only 12 universities(10.3%) published reports on the achievements and performance of the UHSO. Only 29 universities(25.0%) had a continuing education for employees of the UHSO.

• Health Policy and Management
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• v.21 no.2
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• pp.159-178
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• 2011

Korea ranks high among the OECD member countries with a high out-of-pocket share. In 2006, the government implemented in full scale the policy of extending the health insurance benefit coverage. Included in the policy are lowering the out-of-pocket share of patients of serious case and expanding the medical bill ceiling system to mention just a few. This study proposes to confirm effectiveness of the benefit extension policy by identifying changes in 'out-of-pocket expenditure as a share of the ability to pay' and 'incidence rate of catastrophic health care expenditure' of each individual household as manifested before and after the benefit extension policy was implemented. The 1st and 3rd year data from the Korea Welfare Panel Study (KoWePS), conducted by the Korea Institute for Health and Social Affairs (KIHASA), were used for the analysis, where low-income households and ordinary households are sampled separately. While the absolute amount of 'out-of-pocket expenditure' occurred to the average household increased for the period 2005-2007, the 'out-of-pocket expenditure as a share of the ability to pay' decreased. At the same time, the share decreased in the case of low-income households and households with patients of chronic or serious case as contrasted with ordinary households. 'Incidence rates of catastrophic health care expenditure' of ordinary households for 2007 stood at 14.6%, 5.9% and 2.8% at the threshold of 10%, 20% and 30%, respectively. The rates decreased overall between 2005 and 2007, while those of low-income households with patients of serious case statistically significantly increased. An analysis of this study indicates that it is related with the medical bill ceiling system regardless of incomes introduced in 2007.

• Health Policy and Management
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• v.23 no.3
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• pp.224-232
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• 2013

Background: This study was a comparative analysis of the major curriculum for 2-year, 3-year, and 4-year colleges of the department of health administration in Korea. Methods: Among 45 Korean colleges registered with the department of health administration as of 2012, finally 25 colleges were selected by establishing the department of health administration more than 5 years ago, excluding government's financial support, and taking regional locations into account. Results: First, generally 2-year colleges was not the relationships between organizational philosophy/purposes and major course in comparison to those of 3-year or 4-year colleges. Second, the composition of credits in the major course appears to be higher for 3-year, 2-year, and 4-year colleges, respectively. Third, subjects related to basic medicine and medical records were included more often in 2-year, 3-year, and 4-year colleges, respectively, and health policy issues were covered more in 4-year, 3-year, and 2-year colleges, respectively. Fourth, the number of students per full-time professor in 2-year colleges was much higher than that in 3-year and 4-year colleges, and the employment rate of graduates for 4-year colleges was found to be higher than that for 2-year and 3-year colleges. Conclusion: Although this study has limitations with regard to the selection of research subjects, it provides baseline data for establishing the health administration required for training competent future professionals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1848-1868
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• 2014

Multiple-in multiple-out (MIMO) in long-term evolution (LTE) is an essential factor in achieving high speed data rates and spectral efficiency. The unexpected growth in data rate demand has pushed researchers to extend the benefits of multi-user MIMO. The multi-user MIMO system can take full advantage of channel conditions by employing efficient adjustment techniques for scheduling, and by assigning different modulation and coding rates. However, one of the critical issues affecting this feature is the appropriate estimation of channel quality indicator (CQI) to manage the allocated resources to users. Therefore, an accurate CQI estimation scheme is required for the multi-user MIMO transmission to obtain significant improvements on spectral efficiency. This paper presents overviews of multi-user MIMO in LTE/LTE-advanced systems. The link adaptation, scheduling process, and different factors that affect the reliability of CQI measurements are discussed. State-of-the-art schemes for the post-processing CQI estimation, and the comparisons of various CQI estimation schemes to support multi-user MIMO are also addressed.