• Title/Summary/Keyword: Unit production cost

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A Case Study on the Process Improvement Using JIT Concept in a Company (제조업체에 있어서 JIT 개념을 활용한 공정개선 사례연구)

  • 권병우;이동형;김진수;임준묵
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.23 no.55
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    • pp.43-50
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    • 2000
  • Recently, the companies can't avoid the change toward the jobbing production from mass production because manufacturing types are changed from manufacturing-oriented to customer-oriented for the security of competitive power among the related companies. The jobbing production system usually has such problems as low productivity, high unit cost, much stocks, long manufacturing time and one-sided decision of delivery date compared with the mass production. In order to settle these problems in the jobbing production system, we introduced the JIT production system including 3 regulations & 6S activities and Kanban system etc. The effective operation of JIT production system makes the processes efficiently and reduces the unneeded stocks and maximizes the revenue of company.

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Design of Manufacturing Cell and Cellular Layout based on Genetic Algorithm (유전 알고리듬에 기초한 제조셀과 셀 배치의 설계)

  • Cho, Kyu-Kab;Lee, Byung-Uk
    • IE interfaces
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    • v.14 no.1
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    • pp.20-29
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    • 2001
  • This paper presents a concurrent design approach that deals with manufacturing cell formation and cellular layout in Cellular Manufacturing System. Manufacturing cell formation is to group machines into machine cells dedicated to manufacture of part families, and cellular layout problem determines layout of the manufacturing cells within shop and layout of the machines within a cell. In this paper, a concurrent approach for design of machine cell and cellular layout is developed considering manufacturing parameters such as alternative process plans, alternative machines, production volume and processing time of part, and cost per unit time of operation. A mathematical model which minimizes total cost consisting of machine installation cost, machine operating cost, and intercell and intracell movements cost of part is proposed. A hybrid method based on genetic algorithm is proposed to solve the manufacturing cell formation and cellular layout design problem concurrently. The performance of the hybrid method is examined on several problems.

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Economic evaluation of thorium oxide production from monazite using alkaline fusion method

  • Udayakumar, Sanjith;Baharun, Norlia;Rezan, Sheikh Abdul;Ismail, Aznan Fazli;Takip, Khaironie Mohamed
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2418-2425
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    • 2021
  • Monazite is a phosphate mineral that contains thorium (Th) and rare earth elements. The Th concentration in monazite can be as high as 500 ppm, and it has the potential to be used as fuel in the nuclear power system. Therefore, this study aimed to conduct the techno-economic analysis (TEA) of Th extraction in the form of thorium oxide (ThO2) from monazite. Th can be extracted from monazite through an alkaline fusion method. The TEA of ThO2 production studied parameters, including raw materials, equipment costs, total plant direct and indirect costs, and direct fixed capital cost. These parameters were calculated for the production of 0.5, 1, and 10 ton ThO2 per batch. The TEA study revealed that the highest production cost was ascribed to installed equipment. Furthermore, the highest return on investment (ROI) of 21.92% was achieved for extraction of 1 ton/batch of ThO2, with a payback time of 4.56 years. With further increase in ThO2 production to 10 ton/batch, the ROI was decreased to 5.37%. This is mainly due to a significant increase in the total capital investment with increasing ThO2 production scale. The minimum unit production cost was achieved for 1 ton ThO2/batch equal to 335.79 $/Kg ThO2.

Production of High Purity Oxygen by Combination of Membrane and PSA Methods (분리막과 PSA혼합법에 의한 고순도 산소의 제조)

  • Hwang, Sun-Tak
    • Membrane Journal
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    • v.4 no.1
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    • pp.1-8
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    • 1994
  • There are growing needs to produce relatively high purity(99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption(PSA) and membrane process are competitive and less expensive or more convenient than well known cryogenic fractionation technology. A continuous membrane column(CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuously. The oxygen enriched gas generated by a PSA unit, with a concentration of 93~94%, is fed to the CMC that consism of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such as feed flow rate, transmembrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

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Production of High Purity Oxygen by Conbination of Membrane and PSA Methods

  • Hwang, Sun-Tak
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.03a
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    • pp.1-21
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    • 1994
  • There are growing needs to produce relatively high purity (99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption (PSA) and membrane process are competitve and less expensive or more convient than well known crygenic fractionation technology. A continuous membrane colume (CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuosly. The oxygen-enriched gas generated by a PSA unit, with a concentration of 93-94%, is fed to the CMC that consists of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such feed flow rate, transmenbrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

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Ultra-pure water production by integrated electrodialysis-ion exchange/electrodeionization

  • Turek, Marian;Mitko, Krzysztof;Bandura-Zalska, Barbara;Ciecierska, Kamila;Dydo, Piotr
    • Membrane and Water Treatment
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    • v.4 no.4
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    • pp.237-249
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    • 2013
  • Ultra-pure water (UPW), a highly treated water free of colloidal material and of a conductivity less than 0.06 ${\mu}S$, is an essential component required by modern industry. One of the methods for UPW production is the electrodialysis-ion exchange (ED/IE) system, in which the electrodialysis (ED) process is used as a preliminary demineralization step. The IE step can be replaced with electrodeionization (EDI) to decrease the volume of post-regeneration lyes. In this paper, the electrodialysis process carried out to relatively low diluate conductivity was investigated and the costs of UPW production were calculated. The optimal value of desalination degree by ED in the ED/IE and ED/EDI systems was estimated. UPW unit costs for integrated ED/IE and ED/EDI systems were compared to simple ion exchange and other methods for UPW production (RO-IE, RO-EDI). The minimal UPW unit costs in ED/EDI integrated system were estimated as $0.37/$m^3$ for feed TDS 600 mg/L and $0.36/$m^3$ for feed TDS 400 mg/L at 64 $m^3/h$ capacity, which was lower than in the comparable ED/IE integrated system ($0.42-0.44/$m^3$). The presented results suggest that an ED/EDI integrated system may be economically viable.

Optimization of three small-scale solar membrane distillation desalination systems

  • Chang, Hsuan;Hung, Chen-Yu;Chang, Cheng-Liang;Cheng, Tung-Wen;Ho, Chii-Dong
    • Membrane and Water Treatment
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    • v.6 no.6
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    • pp.451-476
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    • 2015
  • Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving the energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum-cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo steady state approach for equipment sizing and the dynamic optimization using overall system mathematical models. The s-SMDDS employing three MD configurations, including the air gap (AGMD), direct contact (DCMD) and vacuum (VMD) types, are optimized. The membrane area of each system is $11.5m^2$. The AGMD system operated for 500 kg/day water production rate gives the lowest unit cost of $5.92/m^3$. The performance ratio and recovery ratio are 0.85 and 4.07%, respectively. For the commercial membrane employed in this study, the increase of membrane mass transfer coefficient up to two times is beneficial for cost reduction and the reduction of membrane heat transfer coefficient only affects the cost of the DCMD system.

${\alpha}-Amylase$ production of Bacillus natto IAM 1212 in the wheat bran medium (밀기울배지를 이용한 Bacillus natto ${\alpha}-Amylase$ 생산)

  • 김광;박인호;선우양일
    • KSBB Journal
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    • v.6 no.2
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    • pp.143-146
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    • 1991
  • The liquifying $\alpha-amylase$ production from B. subtilis, A. oryzae and B. natto using wheat and rice bran as low cost culture medium was investigated. Among 3 strains, B. natto showed heights productivity of $\alpha-amylase$ in the outer wheat bran medium. And the optimum culture condition is pH 6.8 and $37^{\circ}C$ for the production of $\alpha-amylase$. The $\alpha-amylase$ activity of the crude enzyme and the purified enzyme are 256 unit/ml and 10,700 unit/ml, respectivitly. The $\alpha-amylase$ from B. natto cultrtured in outer wheat bran medium was purified into nearly a pure state(98.7%). And the molecular weight of the purified $\alpha-amylase$ was 34,000.

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Application study of heat storage type GSHP system in Apartment building with central cooling and heating facilities using life cycle cost analysis (LCC 분석을 이용한 중앙공급식 공동주택의 수축열식 지열원 히트펌프시스템의 적용연구)

  • Lee, Sang-Hoon;Park, Jong-Woo;Cho, Sung-Hwan
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1497-1502
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    • 2009
  • The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) and central boiler system with individual air conditioning facility which are installed at the same building in the shared an apartment house. Cost items, such as initial construction cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,351,000,000won) is more profitable than central boiler system with individual air conditioning facility by 86.7% initial cost. And SPP appeared 8.0 year overcome the different initial cost by different annual energy cost.

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Distributed ECU System Design for High Speed and High Precision Control of a Marine Engine

  • Lee, Jong-Nyun
    • Journal of information and communication convergence engineering
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    • v.8 no.5
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    • pp.534-538
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    • 2010
  • Efficient control of a marine engine requires an engine control unit (ECU) system that handles fast and precise signal processes for in-coming and out-going signals from fast running engines. In order to handle these roles, the sequential control has been adapted in the ECU system in small and medium size ship engines, which has caused high production cost and complexity of the system. Hence, this paper is focused on developing an distributed ECU system for high speed and high precision control of a marine engine by efficiently combining a CPLD chip and a microprocessor. By sharing load at the MCU with the designed CPLD chip, we could achieve in driving a marine engine with high speed and precise control so that the ECU board has been simplified and its production cost has been reduced.