• Title/Summary/Keyword: Efficiency frontier

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Business Process Evaluation and Case Study for Sequential Application of BPM

  • Song, Young-Woong;Lim, Hyung-Chul;Choi, Yoon-Ki
    • Journal of Construction Engineering and Project Management
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    • v.2 no.2
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    • pp.36-44
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    • 2012
  • Adoption and practical application of BPM yet remains at a theoretic and methodological level for many industrial sectors. As for construction industry, adapting BPM into enterprise resource across all business processes could cause problems due to rapid change in corporate operation systems. Furthermore, it is unable to predict potential risks of business process while BPM are being applied. Therefore, applying BPM model to core strategy and individual task seems more effective than applying BPM model to the entire enterprise resource planning. In this paper, we define BPM and suggest a BPM model by analyzing each business unit in order to evaluate each business unit which is included in the business process architecture based on quantitative standards. This paper also presents a sequential application plan for business process model. Finally, a case study is demonstrated for the application of BPM system, focusing on cost management business, which turned out to be a top priority in the aspect of efficiency and ease based on priority analysis.

Monitoring and control of multiple fraction laws with ring based composite structure

  • Khadimallah, Mohamed A.;Hussain, Muzamal;Naeem, Muhammad Nawaz;Taj, Muhammad;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.10 no.2
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    • pp.129-138
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    • 2021
  • In present article, utilizing the Love shell theory with volume fraction laws for the cylindrical shells vibrations provides a governing equation for the distribution of material composition of material. Isotopic materials are the constituents of these rings. The position of a ring support has been taken along the radial direction. The Rayleigh-Ritz method with three different fraction laws gives birth to the shell frequency equation. Moreover, the effect of height- and length-to-radius ratio and angular speed is investigated. The results are depicted for circumferential wave number, length- and height-radius ratios with three laws. It is found that the backward and forward frequencies of exponential fraction law are sandwich between polynomial and trigonometric laws. It is examined that the backward and forward frequencies increase and decrease on increasing the ratio of height- and length-to-radius ratio. As the position of ring is enhanced for clamped simply supported and simply supported-simply supported boundary conditions, the frequencies go up. At mid-point, all the frequencies are higher and after that the frequencies decreases. The frequencies are same at initial and final stage and rust itself a bell shape. The shell is stabilized by ring supports to increase the stiffness and strength. Comparison is made for non-rotating and rotating cylindrical shell for the efficiency of the model. The results generated by computer software MATLAB.

Spherical Silicon/CNT/Carbon Composite Wrapped with Graphene as an Anode Material for Lithium-Ion Batteries

  • Shin, Min-Seon;Choi, Cheon-Kyu;Park, Min-Sik;Lee, Sung-Man
    • Journal of Electrochemical Science and Technology
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    • v.13 no.1
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    • pp.159-166
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    • 2022
  • The assembly of the micron-sized Si/CNT/carbon composite wrapped with graphene (SCG composite) is designed and synthesized via a spray drying process. The spherical SCG composite exhibits a high discharge capacity of 1789 mAh g-1 with an initial coulombic efficiency of 84 %. Moreover, the porous architecture of SCG composite is beneficial for enhancing cycling stability and rate capability. In practice, a blended electrode consisting of spherical SCG composite and natural graphite with a reversible capacity of ~500 mAh g-1, shows a stable cycle performance with high cycling efficiencies (> 99.5%) during 100 cycles. These superior electrochemical performance are mainly attributed to the robust design and structural stability of the SCG composite during charge and discharge process. It appears that despite the fracture of micro-sized Si particles during repeated cycling, the electrical contact of Si particles can be maintained within the SCG composite by suppressing the direct contact of Si particles with electrolytes.

Rmap+: Autonomous Path Planning for Exploration of Mobile Robot Based on Inner Pair of Outer Frontiers

  • Buriboev, Abror;Kang, Hyun Kyu;Lee, Jun Dong;Oh, Ryumduck;Jeon, Heung Seok
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.10
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    • pp.3373-3389
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    • 2022
  • Exploration of mobile robot without prior data about environments is a fundamental problem during the SLAM processes. In this work, we propose improved version of previous Rmap algorithm by modifying its Exploration submodule. Despite the previous Rmap's performance which significantly reduces the overhead of the grid map, its exploration module costs a lot because of its rectangle following algorithm. To prevent that, we propose a new Rmap+ algorithm for autonomous path planning of mobile robot to explore an unknown environment. The algorithm bases on paired frontiers. To navigate and extend an exploration area of mobile robot, the Rmap+ utilizes the inner and outer frontiers. In each exploration round, the mobile robot using the sensor range determines the frontiers. Then robot periodically changes the range of sensor and generates inner pairs of frontiers. After calculating the length of each frontiers' and its corresponding pairs, the Rmap+ selects the goal point to navigate the robot. The experimental results represent efficiency and applicability on exploration time and distance, i.e., to complete the whole exploration, the path distance decreased from 15% to 69%, as well as the robot decreased the time consumption from 12% to 86% than previous algorithms.

Actual fatigue reliability of structural material: Vibration efficiency

  • Hussain, Muzamal;Khadimallah, Mohamed A.;Ayed, Hamdi;Alshoaibi, Adil;Loukil, Hassen;Alsoruji, Ghazi;Tounsi, Abdelouahed
    • Advances in concrete construction
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    • v.13 no.4
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    • pp.327-337
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    • 2022
  • This paper is concerned with the vibration analysis of middle layer cylindrical shell made of functionally graded material. The outer layers and inner layer are composed of functionally graded and isotropic material respectively. The Rayleigh Ritz method is applied to solve the presented shell dynamics equations. Two configurations are constructed with layers distributions. Fundamental natural frequencies of the three layered cylindrical shell is plotted against the circumferential wave number with different power law exponents. The frequency decreases with the increase of power law exponent. The fundamental natural frequencies first decreases and fall down to its minimum value, after frequencies increases with circumferential wave number. This is due to change in the magnitude of extensional and bending energies of the cylindrical shells. The computer software MATLAB has been employed for the computation of presented frequencies and tested the results obtained in order to assess the accuracy and validity of the cylindrical shell model for predicting the vibration frequencies of cylindrical shell.

Microstructural/geometric imperfection sensitivity on the vibration response of geometrically discontinuous bi-directional functionally graded plates (2D-FGPs) with partial supports by using FEM

  • Varun, Katiyar;Ankit, Gupta;Abdelouahed, Tounsi
    • Steel and Composite Structures
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    • v.45 no.5
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    • pp.621-640
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    • 2022
  • In the present article, the vibration response of a geometrically imperfect bi-directional functionally graded plate (2D-FGP) with geometric discontinuities and micro-structural defects (porosities) has been investigated. A porosity model has been developed to incorporate the effective material properties of the bi-directional FGP which varies in two directions i.e. along the axial and transverse direction. The geometric discontinuity is also introduced in the plate in the form of a circular cut-out at the center of the plate. The structural kinematic formulation is based on the non-polynomial trigonometric higher-order shear deformation theory (HSDT). Finite element formulation is done using C° continuous Lagrangian quadrilateral four-noded element with seven degrees of freedom per node. The equations of motion have been derived using a variational approach. Convergence and validation studies have been documented to confirm the accuracy and efficiency of the present formulation. A detailed investigation study has been done to evaluate the influence of the circular cut-out, geometric imperfection, porosity inclusions, partial supports, volume fraction indexes (along with the thickness and length), and geometrical configurations on the vibration response of 2D-FGP. It is concluded that after a particular cut-out dimension, the vibration response of the 2D FGP exhibits non-monotonic behavior.

A Study on Construction of an Optimal Fossil Fuel Mix: A Portfolio-Based Approach (평균-분산 모형을 이용한 화석에너지원 소비조합 구성에 관한 연구)

  • Cha, Kyungsoo
    • Environmental and Resource Economics Review
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    • v.20 no.2
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    • pp.335-356
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    • 2011
  • In this paper, we attempted to suggest a way to evaluate appropriateness and efficiency for the energy consumption structure. For this, based on Markowitz (1952)' mean-variance portfolio model, we constructed an optimal fossil fuel mix. In constructing the optimal mix, we first defined returns on fossil fuels (oil, coal and natural gas) as TOE (Ton of Oil Equivalent) per $1. Then, by using the dynamic latent common factor model, we decomposed the growth rates of the returns on each fossil fuel into two parts : the common part and the idiosyncratic part. Finally, based on the results from the dynamic latent common factor model, we constructed the optimal fossil fuel mix implied by the mean-variance portfolio model. Our results indicate that for the fossil fuel mix to be on the efficient frontier, it is crucial to reduce oil consumption as low as possible. Moreover, our results imply that it is more efficient to increase natural gas consumption rather than coal consumption in reducing oil consumption. These results are in line with the strategies for the future energy consumption structure pursued by Korea and indicate that reduction in oil use can improve overall efficiency in energy consumption.

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An Analysis of Relationship between Market Structure and Efficiency in Agricultural Products Wholesale Market (농산물도매시장의 시장구조와 효율성 간의 관계분석)

  • Kim, Hyo-Mi;Kim, Yoon-Doo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.238-245
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    • 2020
  • The objective of this study was to analyze the market structure of the Garak Agricultural Products Wholesale Market, which has the greatest influence among agricultural products wholesale markets and plays a key role in domestic agricultural products distribution. In addition, through analysis of the management efficiency of the wholesale market corporation, which is a major distributor of the Garak Market, the connection relationship between the market structure of the Garak Market and the management efficiency of the wholesale market corporation was able to be identified. From 2007 to 2018, it was found that the market structure of Garak Market was a monopoly. In addition, the average production efficiency of the five wholesale market corporations was 0.95, indicating that the wholesale market corporation in Garak Market has an efficient production structure with high output compared to input. Therefore, in order to activate the agricultural products wholesale market and protect the rights of producers and consumers based on the analysis results, it is necessary to implement a policy that can establish a competition system among agricultural products wholesale market distributors.

Evaluation of the operational efficiency of major coastal ports in China based on the PCA-DEA model (PCA-DEA 모델을 기반으로 한 중국 주요연안 항만의 운영 효율성 평가)

  • Haiqing Zhang;Hyangsook Lee
    • Journal of Korea Port Economic Association
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    • v.40 no.1
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    • pp.87-118
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    • 2024
  • Coastal ports play an essential role in developing a country and a city. Port efficiency is an important factor affecting port trade, and the importance of port efficiency for port performance has been recognized in previous literature. DEA (Data Envelopment Analysis) and SFA (Stochastic Frontier Analysis) are widely used in this field of research. However, these two methods are limited in selecting input and output variables. In addition, the literature studies on Chinese coastal ports mainly focus on the study of port clusters in local areas, which lacks a holistic approach and generally lacks up-to-date data. Therefore, to fill the gap in this area of research, this paper introduces a model combining principal component analysis and data envelopment analysis to analyze the operational efficiency of the top 17 coastal ports in China in terms of throughput based on the most recent data available in 2021. This paper identifies container throughput as the output variable, and 13 second indicators are selected as input variables from four primary indicators: land, capital, labor, and infrastructure. Four principal components were selected from 13 second indicators using PCA.After that, DEA (BBC) and DEA (CCR) were used to analyze the 17 ports, among which five were Shanghai, Ningbo-Zhoushan, Guangzhou, Xiamen, and Dongguan, respectively, DEA efficient, and the remaining 12 ports were non-DEA efficient. Finally, improvement directions for each port are derived, and brief suggestions are made. This paper provides some reference value for developing and constructing coastal ports in China.

A Comparative Study on the International Competitiveness of Korea-China Cultural Products Trade (한중 문화상품무역 국제경쟁력 비교 연구)

  • Zheng, Yingrong;Bae, Ki-Hyung;Li, Na
    • The Journal of the Korea Contents Association
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    • v.22 no.9
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    • pp.349-359
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    • 2022
  • At present, with the diversified development of the global economy, the trade of cultural products has become an important factor affecting the competition of comprehensive strength among countries. As a neighboring country to China, South Korea has a similar cultural development environment to China. As an important pillar of South Korea's economy, cultural product trade, its development experience has reference significance for China. This paper adopts literature research method, comparative analysis method and empirical analysis method to conduct research. The article firstly analyzes the export level of China and South Korea from the scale of the import and export of cultural products, and finds the difference between the import and export of cultural products between the two countries. Then, it compares and analyzes the insufficiency of China's cultural product trade structure and the advantage of Korea's cultural product trade structure. Finally, this paper uses the stochastic frontier gravity model to conduct empirical analysis and draws relevant conclusions about the trade potential of cultural products between China and South Korea. The research results show that: (1) the international competitiveness of cultural products trade in China and South Korea is relatively high, but the competitiveness of China's cultural products has been improved slowly; (2) compared with South Korea, China's cultural product exports are affected by trade inefficiency factors larger. (3) The improvement of government efficiency has a great effect on reducing the inefficiency of trade in China.