• Korean Journal of Pharmacognosy
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• 제52권3호
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• pp.157-162
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• 2021

The heat-mediated reflux apparatus extraction of Paeonia lactiflora Pall. has been widely used as a traditional extraction method. In this paper, the microwave apparatus extraction method of Paeonia Radix was performed and the active ingredients and functional constituents were compared with the reference extraction method. The most effective extraction condition of albiflorin using the microwave was 120℃ in 50% methanol, and paeoniflorin was maximally extracted at 60℃. The reduced level of paeoniflorin molecule at high-pressure and high-temperature extraction condition was caused by the molecular instability. Additionally, the microwave extraction of 50% methanol extracts at 150℃ showed the highest functional constituents determined by in vitro DPPH radical scavenging activity, polyphenol concentration, and tyrosinase inhibition assay. The microwave apparatus was adapted as a rapid, low-cost, and environmentally friendly method to extract active ingredients and the practical extraction conditions of Paeonia Radix can be used in industrial applications.

• 전기의세계
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• 제27권2호
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• pp.53-63
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• 1978

The problem of optimally controlling a time-delay control system to a function as the final target is inverstigated. Necessary conditions are presented in the form of Pontryagin's maximum principle, and it is further shown that they are also sufficient for linear systems with a convex cost functional. Several examples are given to illustrate the results.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.262-267
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• 2003

At process of production according to development of accumulation degree of semi-conductor element, because functional mistake examination time required increases, is becoming big obstacle factor in cost-cutting. Studied pattern generator that generate pattern and address that is bundle enemy to process these controversial point effectively.

• Journal of Distribution Science
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• 제20권5호
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• pp.119-127
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• 2022

Purpose: The purpose of this study is to analyze the Cost-Effectiveness Analysis (CEA) of wholesale and retail brokerage businesses in Korea. And give managerial implications and contribute to academics. Research design, data and methodology: This research empirically analyzes the relationship between expenses and business performance. As for business performance, this research considered two financial performances; sales and profit. As for antecedent variables, this research measured three cost investment expenses; human resource management (HRM), marketing (MKT) and corporate social responsibility (CSR). This research used frequency analysis, correlation analysis, stepwise regression analysis and curve estimation analysis. Results: The result shows that HRM and CSR positive significant influence on sales yet marketing negatively significant influence on sales. And for profit, HRM and CSR give a positive significant influence. However, marketing's influence was not significant. According to curve estimation analysis, the relation between individual cost and performance, best functional relation was all quadratic functions. Some results show ∩ shape and others show shape. Conclusions: Based on this study result, implications for practical management to Wholesale and Retail Brokerage companies in Korea. And the contribution to academics is expected. Also, based on the limitation of this study, future research is suggested.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제20권42호
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• pp.99-109
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• 1997

This paper considers to determine the processing workstation of parts and number of machines at workstations in multi-stage manufacturing system. Several part types are processed simultaneously through multi-stage, which consist of several workstations. The machines in each stage are identical in function, but non-identical in functional performance depending on workstations. Two models are suggested. One is assumed that a part type can be processed at the only one workstation in each processing stage. The other is assumed that a part type can be processed at several workstations. Decision criteria is to minimize the sum of the processing cost, travel cost and machine setup cost. Model formulations are presented, and a numerical example is shown.

• Journal of the Korean Operations Research and Management Science Society
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• 제11권1호
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• pp.44-50
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• 1986

In this paper, we find optimal policy for the (Q, r) inventory model under the lead time uncertainty. The (Q, r) inventory model is such that the fixed order quantity Q is placed whenever the level of on hand stock reaches the reorder point r. We first develop the single level inventory model as the basis for the analysis multi-level distribution systems. The functional problem is to determine when and how much to order in order to minimize the expected total cost per unit time, which includes the set up, inventory holding and inventory shortage cost. The model, then, is extended to the multi-level distribution system consisting of the factory, warehouses and retailers. In this case, we also find an optimal policy which minimizes the total cost of the contralized multi-level distribution system.

• Advanced Composite Materials
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• 제16권2호
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• pp.135-149
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• 2007

In the automobile industry, structural health monitoring of fiber reinforced polymer composite parts is a widespread need for maintenance before breakdown of the functional elements or a complete vehicle. High performance sensors are generally used in many of the structural health monitoring operations. Within this study, a carbon fiber sewing thread has been used as a low cost laminate failure sensing element. The experimentation plan was set up according to the electrical conductance and flexibility of carbon fiber threads, advantages of preforming operations, and sewing mechanisms. The influence of the single thread damages by changing the electrical resistance and monitoring the impact location by using carbon thread sensors has been performed. Innovative utilization of relatively cost-effective carbon threads for monitoring the delamination of metallic inserts from the basic composite laminate structure is a highlighting feature of this study.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제21권46호
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• pp.19-32
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• 1998

This paper addresses the processing route of parts and economic design in flexible manufacturing systems (FMSs) employing AGVs for Transport. Parts are processed through several workstations according to operation sequences. The machine of each workstation can do multiple operation functions. The operation stage of a part can be processed in several workstations, which are non-identical in functional performance. The objective of this paper is to determine the processing route of parts, number of machines at each workstation, number of vehicles. The model is assumed that the operation stage of parts can be processed at the only one among several available workstations. Parts are transported by automated guided vehicle system(AGVS). The decision criteria is to minimize the sum of processing cost, travel cost, operating cost. A model formulation is represented. A solution algorithm is suggested by using mathematical programming and simulation technique, and a numerical example is shown.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1195-1200
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• 2009

Two important concepts in VE are "function" and "cost." Cost can be expressed quantitatively. Unlike cost, the function can only be expressed qualitatively. Thus, to accurately evaluate the performance in VE analysis, it is required that the functional aspect should be considered a qualitative one. This study suggests a procedure of function oriented evaluation which can evaluate function enhancement of a VE proposal more logically and objectively. To conduct this study, problems were induced via case analysis, and solutions were found. In addition, the existing simple evaluation procedures were corrected, and a function enhancement evaluation procedure via function classification was suggested. For function classification, the use of the concepts, which were "intended function" and "additionally obtained function," was suggested. Function oriented evaluation procedure to VE proposals which is suggested in this study is expected to be a great help in treating valuable functions through VE job plan.

• International conference on construction engineering and project management
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.179-187
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• 2022

The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.