• Title/Summary/Keyword: Optimal Operation

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A Study on Content Analysis of the Reading Promotion of Ordinance in Local Governments (자치단체의 독서진흥조례 내용분석)

  • Hong, Eun-Sung;Chang, Woo-Kwon
    • Journal of the Korean Society for information Management
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    • v.32 no.4
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    • pp.107-135
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    • 2015
  • The purpose of this study is to investigate and analyze present condition of enactment and enforcement of regulation for reading culture promotion which is a local statute of the autonomous community of Korea to suggest effective improvement methods for operation of ordinance and regulation. In this research, literature review and regulation analysis were conducted and investigated. The results of this study are as follows. 1) There were 77 ordinances of reading related local statutes of 245 metropolitan and primary local authority and 7 regulations. 2) Ordinances and ordinance regulation of the local government and local government of education are being named variously. 3) Composition of ordinances ordinance regulation were not systematic due to diverse contents of ordinance by local government according to the names of ordinance, and they overlapped with similar contents in general. 4) There were 10 ordinances and 2 official orders for the abolished reading related local statutes of the local government until today. This study suggested the following methods to vitalize the reading culture promotion policy. 1) It would be necessary to improve awareness by promoting the reading promotion policy. 2) Optimal name for local statute and ordinance that considered the environment of reading promotion of local statue need to be assigned, and contents of the ordinance regulation related to reading needs to be consistent. 3) Local statutes need to be established by collecting enough opinions of residents or specialists after thoroughly examining problems of the ordinance before abolition.

A Study on the Assessment of Standard Wage System for Forestry Workers in Korea (임업기능인 임금조사를 통한 직종별 기준임금 산정에 관한 연구)

  • Han, Sang-Kyun;Han, Han-Sup;Woo, Hee-Sung;Choi, Byoung-Koo;Cho, Min-Jae;Cha, Du-Song
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.632-639
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    • 2015
  • Working in the forest would require a wide range of skills and experience for specific tasks which involve with a high level of risks to worker's safety. However, there has been a concern on the current standard wage system for forest workers because it does not effectively reflect the characteristics of typical working conditions in the forest. In addition, the current standard wages for forestry workers was estimated based on the construction industry's wage system. Therefore, the purpose of this study is to assess a current wage system through the mail survey method and to develop a new wage system for forest worker which effectively reflects skill sets and experience required for successful completion of the work in the forest. We mailed the survey questionnaire consisting of 19 questions to 659 forest workers and received 188 responses resulting in a 28.5% response rate. The results showed that the current average optimal wages of forest worker, special worker and feller were 97,680won/day, 127,559won/day and 152,403won/day, respectively though there were variations depending on the regions. In developing the new standard wage system, this study suggest the current work types(worker, special worker and feller) could be divided into 5 work types (forest-environment workers, forest operations in beginner, forest operations in intermediate, forest operations in advanced and forest equipment operator) reflecting specialty of forest operation thereby stabilizing the new wage system for forest workers.

Analysis of Pure Refrigerant Cycle Design on C3MR Process through Driver Selection (동력 공급 장치 선택을 통한 C3MR 공정의 순수냉매 사이클 설계 분석)

  • Lee, Inkyu;Tak, Kyungjae;Lim, Wonsub;Moon, Il;Kim, Haksung;Choi, Kwangho
    • Journal of the Korean Institute of Gas
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    • v.17 no.3
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    • pp.27-32
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    • 2013
  • Natural gas liquefaction process which is operated under cryogenic condition spends large amount of energy. Most of energy in the natural gas liquefaction process is consumed by compressors. Therefore, minimizing energy consumption of compressors is an important issue in process design and operation. Among various natural gas liquefaction processes, propane pre-cooled mixed refrigerant (C3MR) process consists of mixed refrigerant system and pure refrigerant system. In this study, to find the optimal design of pure refrigerant system, pure refrigerant cycle is simulated on different number of pressure levels and the necessary energy of each design is compared. After that, the driver selection model is applied to analyse each processes, which has different number of equipments, in terms of cost. As the result, the design using many equipments spends lower energy. Using this result, this study suggests standard of process design selection by the cost term.

A PIVOT based Query Optimization Technique for Horizontal View Tables in Relational Databases (관계 데이터베이스에서 수평 뷰 테이블에 대한 PIVOT 기반의 질의 최적화 방법)

  • Shin, Sung-Hyun;Moon, Yang-Sae;Kim, Jin-Ho;Kang, Gong-Mi
    • The KIPS Transactions:PartD
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    • v.14D no.2
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    • pp.157-168
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    • 2007
  • For effective analyses in various business applications, OLAP(On-Line Analytical Processing) systems represent the multidimensional data as the horizontal format of tables whose columns are corresponding to values of dimension attributes. Because the traditional RDBMSs have the limitation on the maximum number of attributes in table columns(MS SQLServer and Oracle permit each table to have up to 1,024 columns), horizontal tables cannot be directly stored into relational database systems. In this paper, we propose various efficient optimization strategies in transforming horizontal queries to equivalent vertical queries. To achieve this goral, we first store a horizontal table using an equivalent vertical table, and then develop various query transformation rules for horizontal table queries using the PIVOT operator. In particular, we propose various alternative query transformation rules for the basic relational operators, selection, projection, and join. Here, we note that the transformed queries can be executed in several ways, and their execution times will differ from each other. Thus, we propose various optimization strategies that transform the horizontal queries to the equivalent vertical queries when using the PIVOT operator. Finally, we evaluate these methods through extensive experiments and identify the optimal transformation strategy when using the PIVOT operator.

Experiment and Simulation of 2-bed PSA for Hydrogen Separation from H2/CH4 Gas Mixture (수소/메탄 혼합 기체로부터 수소 분리를 위한 두 탑 PSA 실험과 전산 모사)

  • Nam, Gi-Moon;Jeong, Byung-Man;Kang, Seok-Hyun;Lee, Chang-Ha;Lee, Byung-Kwon;Choi, Dae-Ki
    • Korean Chemical Engineering Research
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    • v.43 no.2
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    • pp.249-258
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    • 2005
  • A two-column six-step pressure swing adsorption(PSA) process was to study separation of hydrogen from hydrogen and methane($60_{vol}%/40_{vol}%$) binary system onto activated carbon adsorbent. The effects of the feed gas pressure, the feed flowrate and the P/F(purge to feed) ratio on the process performance were evaluated. The cyclic steady-states of PSA process were reached to after 15 cycles. $H_2$ purity increases according as the P/F ratio and pressure increase and the feed flow rate decreases; however, $H_2$ recovery shows an opposite phenomena to the purity. PSA process simulation studied to find optimum operation condition. In the results, 22 LPM feed flowrate, 11 atm adsorption pressure and 0.10 P/F ratio might be optimal values to obtain more than 75% recovery and 99% purity hydrogen. In this study was non-isothermal and non-adiabatic model considering linear driving force(LDF) model and Langmuir-Freundlich adsorption isotherm considered to compare between prediction and experimental data.

Fresh Water Injection Test to Mitigate Seawater Intrusion and Geophysical Monitoring in Coastal Area (해수침투 저감을 위한 담수주입시험 및 지구물리 모니터링)

  • Park, Kwon-Gyu;Shin, Je-Hyun;Hwang, Se-Ho;Park, In-Hwa
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.353-360
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    • 2007
  • We practiced fresh water injection test to identify its applibility as a method of seawater intrusion mitigation technique, and monitored the change of borehole fluid conductivity and the behavior of injected fresh water using borehole multichannel electrical conductivity monitoring and well-logging, and DC resistivity and SP monitoring at the surface. Well-logging and multichannel EC monitoring showed the decrease of fluid conductivity due to fresh water injection. We note that such an injection effect lasts more than several month which means the applibility of fresh water injection as a seawater intrusion control technique. Although SP monitoring did not show meaningful results because of weather condition during monitoring and the defects of electrodes due to long operation time, DC resistivity monitoring showed its effectiveness and applicability as a monitoring and assessment techniques of injection test by means of imaging the behavior and the front of fresh water body in terms of the increase of resistivity with reasonable resolution. In conclusion, we note that geophysical techniques can be an effective method of monitoring and evaluation of fresh water injection test, and expect that fresh water injection may be an practical method for the mitigation of seawater intrusion when applied with optimal design of injection well distribution and injection rate based on geophysical evaluation.

Effects of the Safety and Health Management System on the Performance of the Enterprise: Focus on the Electric Power Corporation (안전보건경영시스템의 운영방침이 기업성과에 미치는 영향: 전기공사업을 중심으로)

  • Kim, Sang-Sig;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.1
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    • pp.135-145
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    • 2020
  • This research is mainly aimed at finding out about the effects of the safety and health management system on corporate performance through systematic operation by efficiently allocating material and human resources within the company by participating all employees and stakeholders in order to prevent and maintain industrial accidents and the optimal working environment, and how to maintain and activate the safety and health management system at the center of electric contractors.The analysis results are as follows. First, management, organizational management and resource preparation will have a positive impact on the management capability of the electric power corporation. It was assessed that the more well-transmitted and understood within the organization, the better the construction plan, the better the equipment management status, the more positively the management capability of electric works was to be achieved. Second, management, organizational management and resource preparation will have a positive impact on corporate management performance.This seems to have a positive effect on a company's business performance when the standards of OHSAS are met with construction plan and construction equipment management are high as related information such as industrial safety and health laws are strengthened and companies' safety and health activities, advanced safety and culture are released to facilitate organizational management.Third, the management ability of the electric power corporation will have a mediated effect on the effect of management, organization management and resource preparation on the performance of the enterprise. This means that the direct effect of the independent variable management organization on corporate management performance is .401 The indirect effect is .168.658 shows that the direct effect of resource preparation on corporate management performance is .423, the indirect effect is .178 and the total effect.It was analyzed at 643.

The Analysis of Assessment Factors for Offshore Wind Port Site Evaluation (해상풍력 전용항만 입지선정 평가항목에 관한 연구)

  • Ko, HyunJeung
    • Journal of Korea Port Economic Association
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    • v.28 no.3
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    • pp.27-44
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    • 2012
  • The offshore wind farm is increasingly attractive as one of future energy sources all over the world. In addition, the capacity of an offshore wind turbine gets larger and its physical characteristics are big and heavy. In this regard, a special port is necessary to assemble, store, and transport the offshore wind systems, supporting to form the offshore wind farms. Thus, this study aims to provide a policy maker which evaluation factors can significantly affect to the optimal site selection of a offshore wind port. For this, Fuzzy-AHP method is applied to capture the relative weights. The results of this study can be summarized as follows. Five criteria in level I was defined such as the accumulation factor, the regional factor, the economic factor, the location factor, and the consortium factor. Of these, the accumulation factor(37.4%), the location factor(34.2%), and the economic factor( 24.5%) were analyzed by major factors. In level II, three assessment items of each factor were selected so that total fifteen items were formed. To sum up, the site selection of offshore wind port should consider the density of the wind industry, cargo volume of securing the economic operation of terminals, the development degree of offshore wind related industry, and the proximity to the offshore wind farms. In other words, the construction of offshore wind port should be paid attention to considering not only the proximity to offshore wind farms but also the preference of turbine manufacturing companies.

Streamflow Estimation using Coupled Stochastic and Neural Networks Model in the Parallel Reservoir Groups (추계학적모형과 신경망모형을 연계한 병렬저수지군의 유입량산정)

  • Kim, Sung-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.195-209
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    • 2003
  • Spatial-Stochastic Neural Networks Model(SSNNM) is used to estimate long-term streamflow in the parallel reservoir groups. SSNNM employs two kinds of backpropagation algorithms, based on LMBP and BFGS-QNBP separately. SSNNM has three layers, input, hidden, and output layer, in the structure and network configuration consists of 8-8-2 nodes one by one. Nodes in input layer are composed of streamflow, precipitation, pan evaporation, and temperature with the monthly average values collected from Andong and Imha reservoir. But some temporal differences apparently exist in their time series. For the SSNNM training procedure, the training sets in input layer are generated by the PARMA(1,1) stochastic model and they covers insufficient time series. Generated data series are used to train SSNNM and the model parameters, optimal connection weights and biases, are estimated during training procedure. They are applied to evaluate model validation using observed data sets. In this study, the new approaches give outstanding results by the comparison of statistical analysis and hydrographs in the model validation. SSNNM will help to manage and control water distribution and give basic data to develop long-term coupled operation system in parallel reservoir groups of the Upper Nakdong River.

Estimation of Kinetic Parameters for Biomass Growth Using Micro-nano Bubbles Reactor (마이크로-나노버블 반응조를 이용한 미생물성장 동력학 계수의 추정에 관한 연구)

  • Han, Young-Rip;Jung, Byung-Gil;Jung, Yoo-Jin;Cho, Do-Hyun;Sung, Nak-Chang
    • Journal of Environmental Science International
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    • v.19 no.5
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    • pp.647-653
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    • 2010
  • The objectives of this research are to evaluate and compare the oxygen transfer coefficients($K_{La}$) in both a general bubbles reactor and a micro-nano bubbles reactor for effective operation in sewage treatment plants, and to understand the effect on microbial kinetic parameters of biomass growth for optimal biological treatment in sewage treatment plants when the micro-nano bubbles reactor is applied. Oxygen transfer coefficients($K_{La}$) of tap water and effluent of primary clarifier were determined. The oxygen transfer coefficients of the tap water for the general bubbles reactor and micro-nano bubbles reactor were found to be 0.28 $hr^{-1}$ and 2.50 $hr^{-1}$, respectively. The oxygen transfer coefficients of the effluent of the primary clarifier for the general bubbles reactor and micro-nano bubbles reactor were found be to 0.15 $hr^{-1}$ and 0.91 $hr^{-1}$, respectively. In order to figure out kinetic parameters of biomass growth for the general bubbles reactor and micro-nano bubbles reactor, oxygen uptake rates(OURs) in the saturated effluent of the primary clarifier were measured with the general bubbles reactor and micro-nano bubbles reactor. The OURs of in the saturated effluent of the primary clarifier with the general bubbles reactor and micro-nano bubbles reactor were 0.0294 mg $O_2/L{\cdot}hr$ and 0.0465 mg $O_2/L{\cdot}hr$, respectively. The higher micro-nano bubbles reactor's oxygen transfer coefficient increases the OURs. In addition, the maximum readily biodegradable substrate utilization rates($K_{ms}$) for the general bubbles reactor and micro-nano bubbles reactor were 3.41 mg COD utilized/mg active VSS day and 7.07 mg COD utilized/mg active VSS day, respectively. The maximum specific biomass growth rates for heterotrophic biomass(${\mu}_{max}$) were calculated by both values of yield for heterotrophic biomass($Y_H$) and the maximum readily biodegradable substrate utilization rates($K_{ms}$). The values of ${\mu}_{max}$ for the general bubbles reactor and micro-nano bubbles reactor were 1.62 $day^{-1}$ and 3.36 $day^{-1}$, respectively. The reported results show that the micro-nano bubbles reactor increased air-liquid contact area. This method could remove dissolved organic matters and nutrients efficiently and effectively.