• Title/Summary/Keyword: Use efficiency

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Photosynthetic Characteristics and a Sensitive Indicator for O3O3-exposed Platanus orientalis (오존에 노출된 버즘나무의 광합성 특성과 민감성 지표)

  • Lee Jae-Cheon;Oh Chang-Young;Han Sim-Hee;Kim Pan-Gi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.3
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    • pp.220-226
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    • 2005
  • We investigated the effect of O3 on the photosynthetic characteristics of oriental plane (Platanus orientalis L.) that is used as a side tree or ornamental tree in Korea. Two-year-old oriental plane seedlings were transplanted to pots and transferred into a closed O3 chamber, Photosynthetic pigment content and photosynthetic characteristics of leaves were measured every three weeks during 100 ppb O3 fumigation. There was no visible foliar injury by O3 exposure and the content of photosynthetic pigments did not show significant differences between control and O3-treated seedlings. But photosynthetic rate, stomatal conductance, and water use efficiency in leaves of O3-treated seedlings were reduced after six weeks of ozone fumigation. In addition, reduction of carboxylation efficiency and photochemical efficiency was observed in leaves of O3-treated seedlings after three weeks and six weeks. In accordance with our results, carboxylation efficiency, the most sensitive parameter to O3 stress, was considered to be a suitable indicator of O3 sensitivity.

A Study on Filtration Efficiency of Several Dust Masks for Stainless Steel arc Welding fume (방진마스크의 Stainless steel arc 용접흄 여과효율에 관한 연구)

  • Song, Kyung-Seuk;Kwon, Yong-Shick;Han, Kuy-Tae;Chung, Kyu-Hyuck;Lee, Yong-Mook;Yu, Il-Je
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.11 no.1
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    • pp.42-47
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    • 2001
  • The purpose of this study was to investigate for filtration efficiency of several dust masks, comparing with filtration efficiency certified by KOSHA(Korea Occupational Safety & Health Agency), and to require of the right use of protective respirators. Using a welding fume generator and chamber, several dust masks, which were widely used in the workplaces in korea, were tested for their filtering efficiency for stainless steel arc welding fume. The filtration efficiency testing system consisted of a welding fume generator, a chamber and a filtration unit. The filtration unit was made of a mask which was inserted into the sampling cassette and another sampling cassette, which contained mixed cellulose ester filter paper. These two cassettes were connected with tubing. Stainless steel arc welding fume generator was delivered into an chamber. The welding fume in the chamber was passed into the filtration unit with flow rate of 30 liter/min. The welding fume filtration efficiency was evaluated by gravimetric measurement. Metal concentrations in the welding fume before and after filtration were measured with inductive coupling plasma analyzer. Following results were obtained: Filtration efficiency of welding fume for common hygienic mask was 63.82% and the average efficiencies for A, B, C, D, E, F and G masks were 94.62%, 96.58%, 83.20%, 82.76%, 77.25%, 86.55% and 93.22%, respectively. Our results indicate that dust masks used widely in the welding workplaces in korea are not proper for protecting worker's health and then the use of fume mask should be required.

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The Efficiency of Container Terminals in Busan and Gwangyang Port (부산항과 광양항의 컨테이너 터미널의 효율성)

  • Mo, Su-Won;Lee, Kwang-Bae
    • Journal of Korea Port Economic Association
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    • v.26 no.2
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    • pp.139-149
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    • 2010
  • This paper analyses the relative efficiency of 13 container terminals based on the data for the period 2003-8 to offer a fresh perspective. There has been abundant empirical research undertaken on the technical efficiency of Busan and Gwangyang port. Most studies have focused on the use of parametric and non-parametric techniques to analyse overall technical efficiency. Here, the framework assumes that terminals use two input to produce one output; the former includes container yard and container crane and the latter container volume. Jarque-Bera indicates that three variables are not normally distributed and the positive skewness shows that all the variables have long right tails. This means there are many small-scaled container terminals. This paper also employs heteroscedastic Tobit model to show the effect of the explanatory variables on the container terminal efficiencies. The Tobit model shows that both container yard and container cranes have positive effect on the container terminal efficiency, but container yard has a higher impact on the efficiency than the container crane.

An objective assessment of the impact of tendon retraction on sleep efficiency in patients with full-thickness rotator cuff tears: a prospective cohort study

  • Ashley E. MacConnell;William Davis;Rebecca Burr;Andrew Schneider;Lara R Dugas;Cara Joyce;Dane H. Salazar;Nickolas G. Garbis
    • Clinics in Shoulder and Elbow
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    • v.26 no.2
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    • pp.169-174
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    • 2023
  • Background: Sleep quality, quantity, and efficiency have all been demonstrated to be adversely affected by rotator cuff pathology. Previous measures of assessing the impact of rotator cuff pathology on sleep have been largely subjective in nature. This study was undertaken to objectively analyze this relationship through the use of activity monitors. Methods: Patients with full-thickness rotator cuff tears at a single institution were prospectively enrolled between 2018 and 2020. Waist-worn accelerometers were provided for the patients to use each night for 14 days. Sleep efficiency was calculated using the ratio of the time spent sleeping to the total amount of time that was spent in bed. Retraction of the rotator cuff tear was classified using the Patte staging system. Results: This study included 36 patients: 18 with Patte stage 1 disease, 14 with Patte stage 2 disease, and 4 patients with Patte stage 3 disease. During the study, 25 participants wore the monitor on multiple nights, and ultimately their data was used for the analysis. No difference in the median sleep efficiency was appreciated amongst these groups (P>0.1), with each cohort of patients demonstrating a generally high sleep efficiency. Conclusions: The severity of retraction of the rotator cuff tear did not appear to correlate with changes in sleep efficiency for patients (P>0.1). These findings can better inform providers on how to counsel their patients who present with complaints of poor sleep in the setting of full-thickness rotator cuff tears.

RRP Loading Patterns and Standard Dimensions for Block Pattern in Membership Wholesale Clubs (Membership Wholesale Club에서의 RRP 적재패턴 및 블록패턴 표준규격에 관한 연구)

  • Jung, Sung-Tae;Han, Kyu-Chul
    • Journal of Distribution Science
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    • v.13 no.7
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    • pp.41-51
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    • 2015
  • Purpose - This study analyzes loading efficiency by loading pattern for package standardization and reduction of logistics costs, along with the creation of revenue for the revenue review panel (RRP) of Membership Wholesale Clubs (MWC). The study aims to identify standard dimensions that can help improve the compatibility of the pallets related to display patterns preferred by the MWC and thereby explore ways to enhance logistics efficiency between manufacturers and retailers through standardization. Research design, data, and methodology - The study investigates and analyzes the current status based on actual case examples, i.e., manufacturer A and Korea's MWC (A company, B company, and C company), and thus devises improvement measures. To achieve this, the case of manufacturer A delivering to MWC was examined, and the actual pallet display patterns for each MWC were investigated by visiting each distribution site. In this study, TOPS (Total Optimization Packaging Software, USA) was used as the tool for pallet loading efficiency simulations the maximum allowable dimension was set to 0.0mm to prevent the pallet from falling outside the parameters, and the loading efficiency was analyzed with the pallet area. In other words, the study focused on dimensions (length x width x height) according to the research purpose and thereby deduced results. Results - The analysis of pallet loading patterns showed that the most preferred loading patterns for loading efficiency according to product specification, such as pinwheel, brick, and block patterns, were used in the case of the general distribution products, but the products were configured with block patterns in most cases when delivered to MWCs. The loading efficiency by loading pattern was analyzed with respect to 104 nationally listed standard dimensions. Meanwhile, No.51 (330 × 220mm) of KS T 1002 (1,100 × 1,100mm) was found to be the dimension that could bring about an improved loading efficiency, over 90.0% simultaneously in both the T-11 and T-12 pallet systems in a loading pattern configuration with the block pattern only, and the loading efficiency simulation results also confirmed this as the standard dimension that can be commonly applied to both the T-11 pallet (90.0%) and the T-12 pallet (90.7%) systems. Conclusions - The loading efficiency simulation results by loading pattern were analyzed: For the T-11 pallet system, 17 standard dimension sizes displayed the loading efficiency of 90.0% or more as block patterns, and the loading capacity was an average of 99.0%. For the T-12 pallet system, 35 standard dimension sizes displayed the loading efficiency of more than 90% as block patterns (the average loading efficiency of 98.6%). Accordingly, this study proposes that the standard dimensions of 17 sizes with the average loading efficiency of 99.0% should be applied in the use of the T-11 pallet system, and those of 35 sizes with the average loading efficiency of 98.6% should be reviewed and applied in the use of the T-12 pallet system.

Analysis of Research and Development Efficiency of Artificial Intelligence Hardware of Global Companies using Patent Data and Financial data (특허 데이터 및 재무 데이터를 활용한 글로벌 기업의 인공지능 하드웨어 연구개발 효율성 분석)

  • Park, Ji Min;Lee, Bong Gyou
    • Journal of Korea Multimedia Society
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    • v.23 no.2
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    • pp.317-327
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    • 2020
  • R&D(Research and Development) efficiency analysis is a very important issue in academia and industry. Although many studies have been conducted to analyze R&D(Research and Development) efficiency since the past, studies that analyzed R&D(Research and Development) efficiency considering both patentability and patent quality efficiency according to the financial performance of a company do not seem to have been actively conducted. In this study, measuring the patent application and patent quality efficiency according to financial performance, patent quality efficiency according to patent application were applied to corporate groups related to artificial intelligence hardware technology defined as GPU(Graphics Processing Unit), FPGA(Field Programmable Gate Array), ASIC(Application Specific Integrated Circuit) and Neuromorphic. We analyze the efficiency empirically and use Data Envelopment Analysis as a measure of efficiency. This study examines which companies group has high R&D(Research and Development) efficiency about artificial intelligence hardware technology.

A Study on the Technology Transfer Efficiency for Public Institutes Using DEA Model (DEA 모형을 이용한 공공연구기관의 기술이전 효율성 분석에 관한 연구)

  • Hyon, Man-Sok;Yoo, Wang-Jin
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.31 no.2
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    • pp.94-103
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    • 2008
  • This study measured technology transfer efficiency for public institutes. The study made use of DEA being one of the non-parametric linear programming to evaluate technology transfer efficiency for public institutes and to measure technology efficiency, pure technical efficiency and scale efficiency. The measurement of the technology transfer efficiency for public institutes was as follows: The cause of the technology transfer inefficiency was affected by pure technical inefficiency more than by scale inefficiency. Public institutes' RTS(Return To Scale) value varied depending upon the features of the organizations than the features of the regions. Public research institutes' RTS value is more effective than universities' RTS value. We compared the RTS group with the RTS of Projected DMU groups. The RTS group had constant returns to scale effect while the RTS of the Projected DMU had increasing returns to scale effect. The technology transfer efficiency of public institutes varied depending upon the features of the organizations and regions : The technology transfer efficiency of public institutes were as follows : public research institutes at the metropolitan area, public research institutes at the local areas, universities at the metropolitan area and universities at the local areas. In other words, the technology transfer efficiency was affected by organizational characteristics more than by regional characteristics at the place where public institutes were located.

Prediction of Potential CO2 Reduction through Ground Transportation Modal Shift with Fu7el Type and Scenarios (연료원별 온실가스배출량을 고려한 육상교통수단에서의 Modal Shift 효과)

  • Kim, Cho-Young;Lee, Cheul-Kyu;Kim, Yong-Ki
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.521-527
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    • 2011
  • Korea announced GHG reduction goal, 30% reduction compare with 2020 BAU and reduction target for each industry sector is planning. Transportation sector also trying to make effective technical and political counterplan of allocated GHG reduction target such as material lightening, energy efficiency improvement and Modal shift technology and so on. Modal Shift is shifting low energy efficiency vehicle to high energy efficiency vehicle which is economically meaningful under current market conditions. We can get not only energy efficiency improvement but also GHG reduction effect through modal shift. Modal Shift is effectively applying and studied in logistics field in Europe and Japan and one of the Indian companies has been registered CDM project activity involving modal shift from roadways to railways for finished goods. In this study, the scenarios are developed with detail modal shift ratio and fuel type base on state of road and rail use and GHG emission factor for each fuel type from MLTM. This result can be used as basic information to improve policies and promote increasing use of train which is more environment friendly transportation vehicle.

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Improvement of free-space optical interconnection efficiency by using circular aperture CGH

  • Shin, Chang-Mok;Seo, Dong-Hoan;Cho, Kyu-Bo;Kim, Cheol-Su;Lee, Ha-Woon;Kim, Soo-Joong
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.9-11
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    • 2002
  • We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

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Study on the Rankine Cycle using Ammonia-Water Mixture as Working Fluid for Use of Low-Temperature Waste Heat (저온폐열 활용을 위한 암모니아-물 혼합물을 작업유체로 하는 랭킨사이클에 관한 연구)

  • Kim, Kyoung-Hoon;Kim, Se-Woong;Ko, Hyung-Jong
    • Journal of Hydrogen and New Energy
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    • v.21 no.6
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    • pp.570-579
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    • 2010
  • Since the temperature of waste heat source is relatively low, it is difficult to maintain high level of efficiency in power generation when the waste heat recovery is employed in the system. In an effort to improve the thermal efficiency and power output, use of ammonia-water mixture as a working fluid in the power cycle becomes a viable option. In this work, the performance of ammonia-water mixture based Rankine cycle is thoroughly investigated in order to maximize the power generation from the low temperature waste heat. In analyzing the power cycle, several key system parameters such as mass fraction of ammonia in the mixture and turbine inlet pressure are studied to examine their effects on the system performance. The results of the cycle analysis find a substantial increase both in power output and thermal efficiency if the fraction of ammonia increases in the working fluid.