• Title/Summary/Keyword: Management & operations step

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A Study on the Construction of Cutting Scenario for Kori Unit 1 Bio-shield considering ALARA

  • Hak-Yun Lee;Min-Ho Lee;Ki-Tae Yang;Jun-Yeol An;Jong-Soon Song
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4181-4190
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    • 2023
  • Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm2/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

Improving Construction Operations Through Applications of 6 Sigma Management Techniques for Superstore Projects (6시그마 기법의 적용을 통한 대형 할인점 공사의 시공성과 향상)

  • Lee, Seung-Hyun;Lee, Hang-Bok;Park, Chan-Sik;Hong, Sung-Ho
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.4
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    • pp.185-193
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    • 2007
  • In order to improve the performance of succeeding superstore construction projects, it is essential to find out an effective way for applying the opportunities of improvement on their repetitive construction process based upon the analysis of various success or failure cases occurred on previous similar projects. This research study suggests a way to improve their construction process through the applications of six sigma techniques on superstore construction projects. A literature review was implemented on the basic concept of six sigma and its general performance steps, and the step by step applications of six sigma techniques were accomplished regarding to the speciality of superstore construction projects. The opportunities of improvement for superstore projects were figured out, and the result of their applications on other superstore projects was analyzed. As a result, it was found that the adoption rate of identical success or failure cases was increased. Also, there were several improvement effects on the projects such as $10{\sim}20$ days of time savings by projects, decrease of reworks by preventing failure cases, quality and safety improvement. These results indicate that the six sigma techniques are applicable and valuable for improving the repetitive process of superstore construction projects.

A Study on the Construction for Transfer System between Tram and Public Traffic System - In the Place of Changwon Area - (노면전철과 대중교통수단 간의 환승체계 구축에 관한 연구 - 창원 지역을 중심으로 -)

  • Choi, Yang-Won;Park, Do-Yun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.273-286
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    • 2013
  • Recently, due to problems with subway and bus operations, a need has emerged for a solution such as the introduction of an Advanced Transit System. In several municipalities, systems have been introduced using light rail as AGT urban aesthetics construction. There is high inhibition and civil cases are delayed by more environmentally friendly and accessible remedies. For the purpose of this study, Changwon city would be transformed to have an environmentally friendly transportation system such as a tram with an overview. Features, advantages, and disadvantages are analyzed, and systems are established the existing public transport routes by transfer system. Changwon city's tram plan is first step in open in year 2018, and second step with the opening goal of the year 2021, and the total line length of 33.9 km, the station will be built in the 38 locations. and also in 2011 a feasibility study, evaluated a low economic as B/C to 0.88, but it evaluated the high value of the policy analysis as AHP to 0.502. However, introduction of a tram project that should precede the as following condition. The first step in Changwon city's tram plan would be as follows : The introduction of the tram system would demand traffic management along with a restructuring of the bus system, and the tram system would be selected for domestic realities. Secondly, the introduction of trams would comprehend the advanced traffic composition in accordance with the consensus of the citizenship, and a legal system should be established for the introduction of the trams.

A Contemplation on Measures to Advance Logistics Centers (물류센터 선진화를 위한 발전 방안에 대한 소고)

  • Sun, Il-Suck;Lee, Won-Dong
    • Journal of Distribution Science
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    • v.9 no.1
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    • pp.17-27
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    • 2011
  • As the world becomes more globalized, business competition becomes fiercer, while consumers' needs for less expensive quality products are on the increase. Business operations make an effort to secure a competitive edge in costs and services, and the logistics industry, that is, the industry operating the storing and transporting of goods, once thought to be an expense, begins to be considered as the third cash cow, a source of new income. Logistics centers are central to storage, loading and unloading of deliveries, packaging operations, and dispensing goods' information. As hubs for various deliveries, they also serve as a core infrastructure to smoothly coordinate manufacturing and selling, using varied information and operation systems. Logistics centers are increasingly on the rise as centers of business supply activities, growing beyond their previous role of primarily storing goods. They are no longer just facilities; they have become logistics strongholds that encompass various features from demand forecast to the regulation of supply, manufacturing, and sales by realizing SCM, taking into account marketability and the operation of service and products. However, despite these changes in logistics operations, some centers have been unable to shed their past roles as warehouses. For the continuous development of logistics centers, various measures would be needed, including a revision of current supporting policies, formulating effective management plans, and establishing systematic standards for founding, managing, and controlling logistics centers. To this end, the research explored previous studies on the use and effectiveness of logistics centers. From a theoretical perspective, an evaluation of the overall introduction, purposes, and transitions in the use of logistics centers found issues to ponder and suggested measures to promote and further advance logistics centers. First, a fact-finding survey to establish demand forecast and standardization is needed. As logistics newspapers predicted that after 2012 supply would exceed demand, causing rents to fall, the business environment for logistics centers has faltered. However, since there is a shortage of fact-finding surveys regarding actual demand for domestic logistic centers, it is hard to predict what the future holds for this industry. Accordingly, the first priority should be to get to the essence of the current market situation by conducting accurate domestic and international fact-finding surveys. Based on those, management and evaluation indicators should be developed to build the foundation for the consistent advancement of logistics centers. Second, many policies for logistics centers should be revised or developed. Above all, a guideline for fair trade between a shipper and a commercial logistics center should be enacted. Since there are no standards for fair trade between them, rampant unfair trades according to market practices have brought chaos to market orders, and now the logistics industry is confronting its own difficulties. Therefore, unfair trade cases that currently plague logistics centers should be gathered by the industry and fair trade guidelines should be established and implemented. In addition, restrictive employment regulations for foreign workers should be eased, and logistics centers should be charged industry rates for the use of electricity. Third, various measures should be taken to improve the management environment. First, we need to find out how to activate value-added logistics. Because the traditional purpose of logistics centers was storage and loading/unloading of goods, their profitability had a limit, and the need arose to find a new angle to create a value added service. Logistic centers have been perceived as support for a company's storage, manufacturing, and sales needs, not as creators of profits. The center's role in the company's economics has been lowering costs. However, as the logistics' management environment spiraled, along with its storage purpose, developing a new feature of profit creation should be a desirable goal, and to achieve that, value added logistics should be promoted. Logistics centers can also be improved through cost estimation. In the meantime, they have achieved some strides in facility development but have still fallen behind in others, particularly in management functioning. Lax management has been rampant because the industry has not developed a concept of cost estimation. The centers have since made an effort toward unification, standardization, and informatization while realizing cost reductions by establishing systems for effective management, but it has been hard to produce profits. Thus, there is an urgent need to estimate costs by determining a basic cost range for each division of work at logistics centers. This undertaking can be the first step to improving the ineffective aspects of how they operate. Ongoing research and constant efforts have been made to improve the level of effectiveness in the manufacturing industry, but studies on resource management in logistics centers are hardly enough. Thus, a plan to calculate the optimal level of resources necessary to operate a logistics center should be developed and implemented in management behavior, for example, by standardizing the hours of operation. If logistics centers, shippers, related trade groups, academic figures, and other experts could launch a committee to work with the government and maintain an ongoing relationship, the constraint and cooperation among members would help lead to coherent development plans for logistics centers. If the government continues its efforts to provide financial support, nurture professional workers, and maintain safety management, we can anticipate the continuous advancement of logistics centers.

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Establishment of the roof model and optimization of the working face length in top coal caving mining

  • Chang-Xiang Wang;Qing-Heng Gu;Meng Zhang;Cheng-Yang Jia;Bao-Liang Zhang;Jian-Hang Wang
    • Geomechanics and Engineering
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    • v.36 no.5
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    • pp.427-440
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    • 2024
  • This study concentrates on the 301 comprehensive caving working face, notable for its considerable mining height. The roof model is established by integrating prior geological data and the latest borehole rock stratum's physical and mechanical parameters. This comprehensive approach enables the determination of lithology, thickness, and mechanical properties of the roof within 50 m of the primary mining coal seam. Utilizing the transfer rock beam theory and incorporating mining pressure monitoring data, the study delves into the geometric parameters of the direct roof, basic roof movement, and roof pressure during the initial mining process of the 301 comprehensive caving working face. The direct roof of the mining working face is stratified into upper and lower sections. The lower direct roof consists of 6.0 m thick coarse sandstone, while the upper direct roof comprises 9.2 m coarse sandstone, 2.6 m sandy mudstone, and 2.8 m medium sandstone. The basic roof stratum, totaling 22.1 m in thickness, includes layers such as silty sand, medium sandstone, sandy mudstone, and coal. The first pressure step of the basic roof is 61.6 m, with theoretical research indicating a maximum roof pressure of 1.62 MPa during periodic pressure. Extensive simulations and analyses of roof subsidence and advanced abutment pressure under varying working face lengths. Optimal roof control effect is observed when the mining face length falls within the range of 140 m-155 m. This study holds significance as it optimizes the working face length in thick coal seams, enhancing safety and efficiency in coal mining operations.

Cognitive Characteristics and Learning Needs of Economically Disadvantaged Gifted Students (소외계층 영재학생의 인지특성과 학습요구)

  • Park, Minjung;Park, Jiyeon;Jeon, Dongryul;Lee, Kyung-Sook
    • Journal of Gifted/Talented Education
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    • v.26 no.1
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    • pp.1-20
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    • 2016
  • This study explored the cognitive characteristics and learning needs of economically disadvantaged gifted students. Gifted students(n=99), economically disadvantaged gifted students(n=43), and non-gifted students(n=50) participated in intelligence and creativity tests, and took self assessments of meta-cognition, epistemological beliefs, learning style preferences, and personal time usage. Superior abstract reasoning ability of economically disadvantaged gifted students was found because their scores on Raven's Test had risen rapidly compared to the other groups. Economically disadvantaged gifted students showed similar high scores as the gifted student on the Torrance Tests of Creativity Thinking-Figural, but not on Verbal. They were found to have a perception of the positive relationships among effort, learning abilities, and values of learning integrated knowledge with a general plan. However, they showed lower meta-cognitive control abilities than the gifted students in learning management and strategies, epistemological beliefs in value of rational operations, and time usage for learning. It is necessary to assign economically disadvantaged gifted students a task with various step by step methods of approach because these students prefer a new and creative task to difficult ones. Instruction plans such as developing language and meta-cognitive abilities and practical application of learning content was proposed.

Development of a Daily Pattern Clustering Algorithm using Historical Profiles (과거이력자료를 활용한 요일별 패턴분류 알고리즘 개발)

  • Cho, Jun-Han;Kim, Bo-Sung;Kim, Seong-Ho;Kang, Weon-Eui
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.4
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    • pp.11-23
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    • 2011
  • The objective of this paper is to develop a daily pattern clustering algorithm using historical traffic data that can reliably detect under various traffic flow conditions in urban streets. The developed algorithm in this paper is categorized into two major parts, that is to say a macroscopic and a microscopic points of view. First of all, a macroscopic analysis process deduces a daily peak/non-peak hour and emphasis analysis time zones based on the speed time-series. A microscopic analysis process clusters a daily pattern compared with a similarity between individuals or between individual and group. The name of the developed algorithm in microscopic analysis process is called "Two-step speed clustering (TSC) algorithm". TSC algorithm improves the accuracy of a daily pattern clustering based on the time-series speed variation data. The experiments of the algorithm have been conducted with point detector data, installed at a Ansan city, and verified through comparison with a clustering techniques using SPSS. Our efforts in this study are expected to contribute to developing pattern-based information processing, operations management of daily recurrent congestion, improvement of daily signal optimization based on TOD plans.

Efficient RSA-Based PAKE Procotol for Low-Power Devices (저전력 장비에 적합한 효율적인 RSA 기반의 PAKE 프로토콜)

  • Lee, Se-Won;Youn, Taek-Young;Park, Yung-Ho;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.6
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    • pp.23-35
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    • 2009
  • Password-Authenticated Key Exchange (PAKE) Protocol is a useful tool for secure communication conducted over open networks without sharing a common secret key or assuming the existence of the public key infrastructure (PKI). It seems difficult to design efficient PAKE protocols using RSA, and thus many PAKE protocols are designed based on the Diffie-Hellman key exchange (DH-PAKE). Therefore it is important to design an efficient PAKE based on RSA function since the function is suitable for designing a PAKE protocol for imbalanced communication environment. In this paper, we propose a computationally-efficient key exchange protocol based on the RSA function that is suitable for low-power devices in imbalanced environment. Our protocol is more efficient than previous RSA-PAKE protocols, required theoretical computation and experiment time in the same environment. Our protocol can provide that it is more 84% efficiency key exchange than secure and the most efficient RSA-PAKE protocol CEPEK. We can improve the performance of our protocol by computing some costly operations in offline step. We prove the security of our protocol under firmly formalized security model in the random oracle model.

A Sustainability Study Based on Farm Management Value-Chain Structure (농업경영의 가치사슬 구조에 근거한 지속가능성 연구)

  • Cheong, Hoon-Hui;Kim, Sa-Gyun;Heo, Seoung-Wook
    • Journal of Agricultural Extension & Community Development
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    • v.16 no.2
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    • pp.363-384
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    • 2009
  • This study aimed at finding directions for Korean agriculture to establish a new paradigm of sustainable development. Various problematic issues and concerns in the environment necessitate the transformation of Korea's development paradigm from unconditional growth to "Green Growth" through new policies on green value and review of various advanced researches. In this research, the environment-friendly agriculture's problems, particularly in agribusiness were analyzed. Drawing from Michael Porter's Value Chain Analysis, this research developed a value chain model in agriculture that reflects the environment and the present situations. Future directions in the agriculture sector were also discussed. Korea realized food self-sufficiency through the green revolution in the early 1970s. However, a lot of problems have also occurred, including ground and water pollution and the destruction of ecosystems as a result of the overuse of pesticides and chemical fertilizers. In the late 1970s, the growing interest on environment-friendly agriculture led to the introduction of sustainable methods and techniques. Unfortunately however, these were not innovative enough to foster environment-friendly agriculture. Thereafter, the consumers' distrust on agricultural products has worsened and concerns about health have increased. In view of this, the Ministry of Food, Agriculture, Forestry and Fisheries introduced in December 1993 a system of Quality-Certified Products for organic and pesticide-free agri-foods. Although a fundamental step toward the sustainability of the global environment, this system was not enough to promote environment-friendly agriculture. In 2008, Korea's vision is for "Low Carbon Green Growth" to move forward while also coping with climate change. But primary sectors in a typical value chain do not consider the green value of their operations nor look at production from an environmental perspective. In order to attain sustainable development, there is a need to use less resources and energy than what is presently used in Korean agricultural and value production. The typical value chain should be transformed into a "closed-loop" such that the beginning and the end of the chain are linked together. Such structure allows the flow of materials, products and even wastes among participants in the chain in a sustained cycle. This may result in a zero-waste sustainable production without destroying the ecosystem.

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Development of Evaluation Index and Multi-layer Evaluation System for Quality Management of Elderly Long-term Care Institution (노인장기요양기관(시설급여) 평가의 품질관리를 위한 평가지표 개발 및 다층평가시스템 방안)

  • Lee, Sang-Jin;Kim, Yun-Jeong
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.11
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    • pp.1015-1026
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    • 2019
  • The purpose of this study is to develop evaluation indexes for improving the quality of long-term care institutions (facility salary) evaluation in the sense that the applicability and effectiveness of previous studies related to the development of evaluation indexes for long-term care facilities for elderly are insufficient. There was this. To this end, an analytical review of the 2018 long-term care institution (accommodation benefit) evaluation index, an analysis of Japan's elderly long-term care home evaluation index, and the elderly long-term care facility workers in Korea and the special care home for the elderly in Japan FGI on evaluation indicators and evaluation system was conducted. Based on the results of the research, evaluation indicators were developed in terms of supporting users to receive high quality services. The characteristics of the elderly, that is, the characteristics of elderly diseases that are difficult to maintain and improve, the direction and transparency of institutional operation, and the need for terminal care were reflected. Forty-three evaluation indicators were presented, covering institutional operations, environment and safety, beneficiary rights protection, payroll process, and payroll results. In addition, we proposed a four-step multi-level evaluation system that can improve the efficiency of the evaluation process by improving the redundant and unnecessary evaluation process.