• Title, Summary, Keyword: Expected efficiency

Search Result 2,441, Processing Time 0.033 seconds

Calculation of Spectral Efficiency for Estimating Spectrum Requirements of IMT-Advanced in Korean Mobile Communication Environments

  • Chung, Woo-Ghee;Lim, Eun-Taek;Yook, Jong-Gwan;Park, Han-Kyu
    • ETRI Journal
    • /
    • v.29 no.2
    • /
    • pp.153-161
    • /
    • 2007
  • In this paper, we analyze the algorithm of the methodology developed by ITU for the calculation of spectrum requirements of IMT-Advanced. We propose an approach to estimate user density using traffic statistics, and to estimate spectrum efficiencies using carrier-to-interference ratio distribution and capacity theory as well as experimental data under Korean mobile communication environments. We calculate the IMT-Advanced spectrum requirements based on the user density and spectral efficiencies acquired from the new method. In the case of spectral efficiency using higher modulation and coding schemes, the spectrum requirement of IMT-Advanced is approximately 2700 MHz. When applying a $2{\times}2$ multiple-input multiple-output (MIMO) antenna system, it is approximately 1500 MHz; when applying a $4{\times}4$ MIMO antenna system, it is approximately 1050 MHz. Considering that the development of new technology will increase spectrum efficiency in the future, the spectrum requirement of IMT-Advanced in the Korean mobile communication environment is expected to be approximately 1 GHz bandwidth.

  • PDF

Methodological Improvement for the Economic Assessment of Public R&D Programs

  • Hwang, Seogwon
    • STI Policy Review
    • /
    • v.2 no.3
    • /
    • pp.35-44
    • /
    • 2011
  • Korea has rapidly increased R&D investment over the last few decades and the intensity of R&D investment is among the highest in the world; however, there are serious concerns about R&D performance and R&D efficiency. This study is to improve the economic assessment methodology regarding a feasibility study for national R&D programs that are thought to be one of the most prominent ways to enhance R&D efficiency. In order to improve the methodology of economic assessment, a few of important factors such as technical or market uncertainty, spillover effect, and R&D contribution ratio should be covered in the model. The focus of this article is technological and market uncertainty that has a close relation with strategic flexibility and utilization potential to increase the value of R&D programs. To improve the current linear and definitive R&D process, a new framework with strategic flexibility is suggested, in which the result of economic assessment that considers technological and market uncertainty is reflected in planning. That kind of feedback process is expected to enhance the value of the program/project as well as R&D efficiency.

Automatic Measurement of Construction Equipment Efficiency Using a 11-Axis Composite Sensor (11축 복합센서를 통한 건설기계 효율성 측정 자동화 방안)

  • Kwon, Jae-bum;Cho, Dae-gu;Cho, Hun-Hee;Kang, Kyung-In
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • /
    • pp.59-60
    • /
    • 2012
  • A large-scale construction project relies much on the efficiency of construction equipment. Therefore, efficient and accurate measurement on the productivity of construction equipment is one of important task in the construction industry. Based on the motivation, this paper proposes a 11-axis composite sensor for an automatic measurement of construction equipment. A 11-axis composite sensor is composed of a gyroscope, geomagnetic and accelerometer sensor for the purpose of real-time motion captures of construction equipment. It is expected that the proposed system can save considerable time, effort and cost of measuring a efficiency of construction equipment.

  • PDF

A study on the Improvement of the luminous efficiency with new sustaining electrode structurs in ac-PDPs (새로운 유지전극 구조에 의한 ac-PDP 에서의 효율 개선에 관한 연구)

  • Lee, Jae-Young;Shin, Joong-Hong;Park, Chung-Hoo;Cho, Jung-Soo
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1818-1820
    • /
    • 2000
  • Due to recent technology advances, needs for flat panel displays, plasma display panels(PDPs) whose advantages are simple structure, high resolution, wide viewing angle is increasingly expected to be the first flat panel of large screen, walt hanging TVs. But the luminance and luminous efficiency of color PDP is net up to the level of a CRT. So, New electrode shape which is different from the conventional electrode has to propose to improve the luminance and luminous efficiency. In this paper, we suggested new shaped electrodes. In new shaped electrode, the discharge current was reduced compared with conventional type by reducing the unnecessary diffusion loss near the barrier rib. However, the luminance was nearly the same as conventional type. So, the luminous efficiency improved about 35%.

  • PDF

A Study on the Solar Cell Charging Equipment for Hybrid Vehicle (Hybrid 자동차용 Solar Cell 충전장치에 관한 연구)

  • Kim, G.S.;Park, S.C.
    • Journal of the Korean Society of Mechanical Technology
    • /
    • v.13 no.4
    • /
    • pp.157-164
    • /
    • 2011
  • Hybrid car can improve fuel efficiency using a power of motor that is generated during constant-speed or deceleration driving. The motor is located between engine and transmission. But, when voltage of main battery is low, fuel efficiency is low because the voltage can't run the motor. In this situation, this study observed fuel efficiency when using solar cell for assistance power. In order to verify a fuel consumption of hybrid car equipped solar cell for assistance power, the car was tested downtown driving. As hybrid car was equipped solar cell for assistance, fuel consumption was reduced 8.35 % at running air conditioner. And, at air conditioner doesn't work, fuel consumption was reduced 6.88 %. This point of view, CO2 is expected to reduce in similar proportion.

New High-efficiency Power Amplifier System for High-directional Piezoelectric Transducer (고지향성 압전 트랜스듀서용 새로운 고효율 전력 증폭기)

  • Kim, Jin-Young;Kim, In-Dong;Moon, Wonkyu
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.3
    • /
    • pp.383-390
    • /
    • 2018
  • Piezoelectric micro-machined ultrasonic transducers for highly directional speaker need DC bias voltage. Most existing power amplifiers are not suitable for use in highly directional transducers because they are based on AC. In addition, since the piezoelectric micro-machined ultrasonic transducer has a large capacitive reactance, the power efficiency of the power amplifier is very low. Thus this paper proposes a new high efficiency power amplifier with DC bias voltage. In addition, by designing a matching circuit to compensate the capacitive reactance of the micro-machined ultrasonic transducer, the power efficiency of the power amplifier increases. The operating characteristics of the proposed power amplifier was verified by an experimental prototype. The proposed power amplifier is expected to be widely used in designing and implementing other related power amplifiers.

A Study on Unified Packing Standard for Agricultural Products Based on Pallet Stacking Efficiency (팔레트 적재효율을 고려한 농산물 포장상자 통합규격에 관한 연구)

  • Suh, Kyo;Lee, Jeong-Jae;Suh, Byong-Yoon
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.47 no.1
    • /
    • pp.13-22
    • /
    • 2005
  • Despite the variety in sizes and shapes of agricultural products, the unified standardization of packing has been a long time necessity. In this study the stacking efficiency of packing standards for each box using packing Monte Carlo simulation based on the standard pallet is evaluated. As a result of simulation the unified packing standard for agricultural products is suggested by 550$\times$366 mm. With this study it is expected that the unification of the standards can help to increase the utilization of reusable packages and to improve efficiency of agricultural logistics.

Proposal of enhanced treatment process based on actual pilot plant for removal of micropharmaceuticals in sewage treatment plants

  • Lee, Shun-hwa;Park, Yun-kyung;Lee, Miran;Lee, Byung-dae
    • Environmental Engineering Research
    • /
    • v.25 no.4
    • /
    • pp.588-596
    • /
    • 2020
  • This study was carried out to increase the treatment efficiency through the improvement of the conventional biological process, and to propose the optimal treatment direction. The optimal treatment conditions were derived based on the results of the spike damage tests in each single process. The removal efficiency of micropharmaceuticals was further increased when an ozone treatment process was added to the biological process compared to the single process. The soil and activated carbon adsorption process was introduced in the post-treatment to remove the micropharmaceutical residues, and the removal efficiency of the pharmaceduticals in the final effluent was more than 85% in spike damage experiment. In particular, the continuous process of biological treatment-ozone-adsorption could ensure the stable treatment of micropharmaceuticals, which had not been efficiently removed in the single process, as it showed more than 80% removal efficiency. Therefore, it is expected that the addition of the ozone oxidation and activated carbon adsorption process to the existing sewage treatment facilities can contribute to the efficient removal of micropharmaceuticals.

Measuring Operational Efficiency of Korean Online Game Companies with DEA Window Analysis (DEA Window 분석을 이용한 국내 온라인 게임 기업의 운영 효율성 평가)

  • Chun, Hoon;Lee, Hakyeon
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.39 no.3
    • /
    • pp.23-40
    • /
    • 2014
  • This paper measures the operational efficiency of domestic online game companies and analyze its trends and patterns by using data envelopment analysis (DEA). DEA is a non-parametric approach to measuring the relative efficiency of decision-making units (DMUs) with multiple inputs and outputs. 14 online game companies are selected as DMUs and three inputs (number of employees, capital and asset) and three outputs (sales, operating profit and net profit) are selected as DEA variables. First, the output-oriented BCC model and super-efficiency model are employed to measure the static operational efficiency of the online game companies from 2003 to 2012. We also conduct the dynamic analysis with DEA window model to capture the trends of their operational efficiency influenced by internal and external environmental changes. The results are expected to provide fruitful implications for strategic decision making of online game companies and policy making for the online game industry.

Evaluating the Technical Efficiency of Service Operations Using DEA Models: An Application to Contact Center Services (DEA 모형에 의한 서비스 운영의 기술적 효율성 평가: 컨택센터 서비스를 중심으로)

  • Cho, Geon;Lee, Kyoung-Jae;So, Soon-Hu
    • Journal of the Korean Society for Quality Management
    • /
    • v.37 no.2
    • /
    • pp.1-11
    • /
    • 2009
  • Recently, many companies have been very interested in CRM(Customer Relationship Management). Most companies have been also considering the contact center as a key CRM channel, because it is a contact point between customers and companies. It turns out that the contact center handles over 70% of all customer-company interactions and the success or failure of a company can be determined by the customer satisfaction with contact center experiences. Despite of the strategic importance of the contact center, there has been few empirical study on the efficiency of contact center operations in the literature. One of the main purposes of this study is to evaluate the efficiency of contact centers so as to not only identify the current status of contact center operations, but also suggest ways to improve operational efficiency. For this purpose, we apply a non-parametric efficiency measurement method, DEA (Data Envelopment Analysis), to 57 domestic contact centers in order to compare their relative efficiency. It is expected that the measurement methods suggested in this study can be applied to various issues such as service KS certification, outsourcing service management, and the productivity analysis of service personnel.