• Journal of Advanced Marine Engineering and Technology
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• v.29 no.6
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• pp.618-627
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• 2005

In this paper, we have compared and analyzed the performance of high amplifier using Doherty technique to improve linearity and efficiency of base station and repeater Power amplifier for WCDMA. This Doherty amplifier implements with 3dB branch line coupler and $90^{\circ}C$ transmission line The phase offset line is designed to maintain the high linearity and efficiency at the low efficiency Period of the power amplifier CW 1-tone experimental results at the WCDMA frequency $2.11{\sim}2.17GHz$ shows that Doherty amplifier which achieves power add efficiency(PAE) of 50% at 6dB back off the point from maximum output power 52.3 dBm, obtains higher efficiency of 13.3% than class AB Finding optimum bias Point after adjusted gate voltage, Doherty amplifier shows that $IMD_3$ improves 4dB.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.83-92
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• 1990

Adapting two step aeration system to a waste water treatment of W-paper manufactory as Full-Scale Plants, we drew a following conclusion from its practical working. 1. Because BOD removal efficiency was 20% in A-Stage, 90% in B-Stage and total removal efficiency was 97%. It worked treatment plant well and was suitable for effluent water standard as well. Because COD removal efficiency was 42% in A-stage, 71% in B-stage and the total removal efficiency was 94% COD control was possible in effluent water quality. 2. Treatment efficiency according to a load capacity was average 20% in 1.401 BOD kg/m3/d load of A-Stage and average 90% in 0.273 BOD kg/$\textrm {m}^3$ / d load of B-Stage. 3. Treatment efficiency according to a ratio of F/M was 2.657--5.024 kg BOD/kg MLSS/d in A-Stage and BOD removal efficiency was 16-261 in the same stage. The ratio of F/M was 0.068-0.094 kg BOD /kg MLSS/d and BOD removal efficiency ratio was 85-94%. Therefore treatment efficiency could be kept stably and volume of aeration tank could be reduced wholly. 4. Treatment efficiency according to MLSS appeared BOD 20%. COD 42%, in A-Stage and removal efficiency appeared BOD 90%, COD 71% in B-Stage. They were suitable for plan condition. 5. Because of working of complemented treatment plant by AB-Process. 20,000,000 Won a month was saved than the ordinary working cost. Therefore, it was assumed that invested cost could be recollected in 19 months or so consequently.

• Journal of Technology Innovation
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• v.11 no.2
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• pp.151-173
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• 2003

This paper analyses the efficiency and productivity of R&D system across time (1991${\sim}$2000) and 16 OECD countries using multi-output and multi-input non-parametric frontier methods such as DEA (data envelopement analysis) and Malmquist productivity indexes. Malmquist productivity indexes are decomposed into two components measures, namely technical change and efficiency change. To calculate R&D efficiency and productivity, we used R&D stock and the number or researchers as R&D input proxies and the number of adjusted SCI papers and U.S. patent applications as R&D output proxies. Empirical result shows that Switzerland, Canada, U.S., Australia's R&D efficiencies are the highest and Korea's R&D productivity growth is the highest in the sample for the period. Technical efficiency growth was a more important source of productivity growth than technological innovation.

• KSBB Journal
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• v.24 no.1
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• pp.53-58
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• 2009

This study was focused on the investigation of the characteristics of TPH and BTEX removal in oil-contaminated sandy soil and fine soil with injection of microorganisms, nutrients, and surfactants. As the result of the experiments maintained moisture contents by 10${\sim}$20%, the TPH removal efficiency in oil-contaminated sandy soil was the highest in C-1 (microorganisms+nutrients), and the efficiency in C-2 (microorganisms+nutrients+surfactants) was higher than the efficiency in C-0(microorganisms). In 81 days, TPH removal efficiency in case of C-0, C-1 and C-2 showed 51%, 83%, 63% respectively. The results of D group with fine soil showed similar trends as C group, but the TPH removal efficiency of D group was lower than that of C group. Those of both C and D group were the highest in 1 group (microganisms+nutrients). The pH of fine soil was some lower than that of sandy soil or was similar to sandy soil. In 14 days, BTEX removal efficiency in case of C-0, C-1, C-2, D-0, D-1 and D-2 showed 99.8%, 99.4%, 96.0%, 99.5%, 99.2%, 96.3% respectively. Those of both C and D group were the highest in 0 group (microganisms).

• Journal of Fashion Business
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• v.26 no.1
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• pp.53-67
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• 2022

The purpose of this study was to compare the appearance similarity between a 3D virtual wedding dress, and a model wearing real dress, and production efficiency, and the possibility of achieving similar results with 3D digital technology. Five wedding dresses for small weddings under the theme of 'Dream Series', were designed and produced in virtual and real dresses to quantitatively compare and analyze the appearance similarity and production efficiency. Experts compared the appearance similarity on the silhouettes, colors, materials, and details, and production efficiency was compared with time and cost. Based on our results, 3D virtual images of four out of the five dresses were similar to the real images. Our efficiency evaluation results showed that the manufacturing time was 45.4% shorter, and the manufacturing cost was 46.1% less than the existing method. This indicated that the wedding dress manufacturing process using 3D virtual software was time and cost saving competitive. Our results also confirmed that 3D virtual software technology has the potential to increase the efficiency of designing and production, and therefore an increase in competitiveness and sales of wedding dresses. Furthermore, 3D technology allows consumers to select and order wedding dresses online through 3D virtual software. This is a great advantage, and it highlights the significance of this research study.

• Journal of Technology Innovation
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• v.28 no.3
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• pp.1-28
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• 2020

This study examines whether the firm with high innovation efficiency realizes high operating performance. We measured innovation efficiency by the ratio of patent applications for R&D expenditure or R&D stock and measured operating performance by the ratio of operating income or operating cash flow to total assets for the following year. The sample consists of 1,880 manufacturing firm-years, which listed on the Korean Exchange between 2014 and 2017. We analyze the effect of innovation efficiency on operating performance using a model of Hirshleifer et al. (2013) results show that both innovation efficiency variables have a significantly positive relationship with the total asset operating margin. Besides, the following year's performance, measured by the total asset operating cash flow ratio, also shows a positive relationship with the two innovation efficiency variables at the 5% and 1% significance levels, respectively. The results indicate that high innovation efficiency firms that link the outcomes of R&D to more patent applications realize higher operating performance. Also, we divided the R&D-intensive and non-R&D-intensive industries and performed the same analysis. As a result, the innovation efficiency has a significant positive effect on operating margin in both industries. However, the effect of innovation efficiency on the operating cash flow is only significant in R&D-intensive industries. This study suggests that the effects of innovation efficiency are more consistent in the R&D-intensive industry. Additionally, we divided the high patent application and low patent applications industries and performed the same analysis. As a result, the innovation efficiency has a significant positive effect on operating margin in both industries. This study suggests that the effects of innovation efficiency are more consistent in the high patent application industry. We show that a firm's innovation efficiency is a critical factor for a firm's performance, while prior studies on the R&D performance have not considered the innovation efficiency of each firm. The evidence suggests that firms not only consider R&D expenditures but also improve the performance of companies by increasing innovation efficiency. Investors need to consider their innovation efficiency when evaluating the value of firms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.287-292
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• 2015

In this paper, we evaluated the performance of D2D advertisement dissemination algorithms with maximum-distance and transmission-efficiency based relay selections with respect to the total number of successfully received users and transmission efficiency. To assume more practical environment, we took into account pre-defined target-areas based on the information of user density and the limit for the maximum number of relay users. Through the simulations we compared the performance results of both D2D advertisement dissemination algorithms with maximum-distance and transmission-efficiency based relay selections according to increment of the number of sectors. And then, we analysed the superiority of algorithm with transmission-efficiency based relay selections more than maximum-distance based relay selections.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.785-798
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• 2016

Purpose: This paper developed the framework for extracting strategies of research and business development (R&BD) based on the data envelopment analysis(DEA). Methods: DEA has been widely utilized in evaluating R&D efficiency. Even though, technology transfer and commercialization has been regarded as the important factors for practical R&D efficiency evaluation, most research have evaluated R&D efficiency by just using the DEA outputs such as the number of patents and papers. The technology transfer, commercialization and relations among costs and generated technology and commercialization are needed to be considered for more practical R&D efficiency evaluation. Thus, this research addressed a method on how to incorporate the commercialization factors into the R&DB efficiency evaluation, and improve the efficiency strategically in terms of R&D and B&D. To achieve this, this research utilized a two-stage network DEA model for R&BD efficiency evaluation. Results: The proposed framework was applied to the 15 public research institutes and the 34 universities for validation. R&BD efficiency for the 15 public research institutes and the 34 universities was evaluated, and the differentiated improvement strategies for the inefficient DMUs to improve their efficient were proposed. Conclusion: The R&BD efficiency would be effectively analyzed based on two-stage network DEA. It would be utilized for the effective strategy planning for cultivating R&BD.

• ETRI Journal
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• v.34 no.6
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• pp.885-891
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• 2012

This paper proposes a high-efficiency power amplifier (PA) with uneven bias. The proposed amplifier consists of a driver amplifier, power stages of the main amplifier with class AB bias, and an auxiliary amplifier with class C bias. Unlike other CMOS PAs, the amplifier adopts a current-mode transformer-based combiner to reduce the output stage loss and size. As a result, the amplifier can improve the efficiency and reduce the quiescent current. The fully integrated CMOS PA is implemented using the commercial Taiwan Semiconductor Manufacturing Company 0.18-${\mu}m$ RF-CMOS process with a supply voltage of 3.3 V. The measured gain, $P_{1dB}$, and efficiency at $P_{1dB}$ are 29 dB, 28.1 dBm, and 37.9%, respectively. When the PA is tested with 54 Mbps of an 802.11g WLAN orthogonal frequency division multiplexing signal, a 25-dB error vector magnitude compliant output power of 22 dBm and a 21.5% efficiency can be obtained.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.205-222
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• 2011

The Korean government continuously increases the R&D investment in order to pursue an economic growth through technological innovation. Hence, the intensity of governmental R&D has increased rapidly. However, the whole amount of the R&D investment is still small compared to developed countries. And the type of R&D policies is more and more changing from the catch-up model to the technology-driven model. Therefore, there is a growing interest in the efficiency of public R&D investment. Hence, many studies on the efficiency of R&D investment have been researched. This study estimated the efficiency of governmental R&D programs considering the technological outcomes, e.g. theses, patents and so on, using DEA(Data Envelopment Analysis) with data of S&T investment and outcomes from NTIS(National S&D Information Service). In addition, we used the Mann-Whitney Test to investigate the characteristics of governmental R&D investment.