• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.101-107
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• 2010

Purpose: The free flap has been widely used as one stage reconstructive procedure the skin and soft tissue defect. The secondary adjuvant operations are often needed for better results as functional and aesthetic compartment. Therefore, we focus on the secondary adjuvant surgeries for better outcome after free flaps. Methods: One hundred ninety six consecutive patients underwent free flaps between January, 2002 and February 2009. The cases constituted ninety two male patients and one hundred four female patients. For the patients who got free flap operation, we investigated secondary adjuvant operations what type of procedures was applied according to the reconstructed sites. All clinical data were based on the patient's medical records. Results: Of one hundred ninety six patients in whom free flap was performed, a total of eighty two patients(41.8%) received the secondary adjuvant operation. Because of many patients got multiple secondary adjuvant operations, the number of the secondary adjuvant operation become one hundred fifty five cases. The most common used procedure is a liposuction, and the second one is a lipoinjection. Conclusion: As the secondary adjuvant operation like a liposuction, lipoinjection, etc., satisfaction for operative result was increased in the aspects of function and aesthetics. So the secondary adjuvant operation in free flap surgeries contributed in raising the patient's quality of life.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.464-468
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• 2007

In cognitive radio systems, secondary users, unlicensed users, can use primary users' spectrum to increase spectrum efficiency. At that time, the systems must satisfy primary users' QoS. When secondary users use cognitive radio systems, secondary users communication can be terminated, because of satisfying primary users' QoS. However, secondary users' communication terminating is not good for both secondary users and whole systems. So, cognitive radio systems need an efficient algorithm for secondary users of admission control and keeping connections. In this paper, we present an algorithm which consist of two part, admission control and connections control.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.46-57
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• 1998

Even though there are some studies on the deep drawing process and process planning, little study has been done on the methodology of process planning of secondary operations of deep drawing such as 'piercins'. In this paper, first, we systematized the methodology of the process planning of secondary operations on axisymmetric cup. Second we described the development of the expert system for their CAPP For these studies, we extracted the knowledge of their process planning from experts and analysed and systemized them. To develop the expert system, rule-based reasoning paradigm is used. The shape information of manufacturing features of secondary operations are manually input to the system through SUI. The process planning results are automatically connected to AutoCAD. We believe that the systematized process knowledge and the development of the expert system for its CAPP could give lots of aids to the associated field.

• Journal of the Korean School Mathematics Society
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• v.16 no.3
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• pp.499-518
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• 2013

The purpose of this study is to examine the preservice secondary mathematics teachers understanding and dimensions of knowledge about definition of irrational numbers and irrational numbers and operations. I adopted a framework consisting of formal dimensions, intuitive numbers, algorithmic dimentions suggested by Tirosh et al.(1998) by adding instrumental dimension for his study. I surveyed 65 preservice secondary mathematics teachers who are in bachelor program and post-bachelor program for teacher certificate by using a questionnaire suggested by Sirotic and Zazkis(2007). The results of this study suggest that 83.1% of the participants gave correct answers in definitions of irrational numbers. 43% of the preservice secondary teachers gave correct answers in adding with irrational numbers. Also 91% of the preservice teachers gave correct answers in multiplying irrational numbers. The preservice teachers appeared to understand irrational numbers and operations at formal dimension. More than half of the preservice teachers gave incorrect answers in adding irrational numbers and a few participants gave incorrect in multiplying irrational numbers. The preservice teachers seemed to understand irrational numbers and operations at intuitive or instrumental dimension. The results also suggest that the preservice secondary mathematics teachers have incorrect understanding about irrational numbers.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.93-104
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• 2007

We consider a supply chain where products are shipped to warehouse from manufacturing system to customers. Products are supplied from either in-house regular manufacturing or the secondary source such as subcontractor. The inventory in warehouse is controlled by base-stock policy, that is, whenever a demand arrives from customer, an order is released to the manufacturing system. Unsatisfied demand is backlogged. The manufacturing system is modeled as M/M/s+1/c queueing system, and the orders exceeding the given limit care blocked and lost. The steady state distribution of the outstanding orders and the throughput of the manufacturing system are functions of the level of engagement In the secondary source. There is a profit obtained from throughput and cost not only due to the engagement of the secondary source in the manufacturing system but also inventory positions. We want to maximize the total production profit minus the total cost of the production system by simultaneously determining the optimal level of engagement of the secondary source and the optimal base-stock level of the inventory. We develop two algorithms : one without guarantee of the optimal solution but with the small number of computations, the other optimal but with more computations.

• Journal of The Korean Association For Science Education
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• v.9 no.2
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• pp.1-12
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• 1989

Secondary schools in Korea have been faced with with several critical problems with regard to science education, with one of the most fundament problems being associated with secondary school science teacher education and in-service training. Therefore this study, which is a part of project for the improvement of science teaching in secondary schools, had its purposes to inquire into the following are as. ${\circ}$systems for science teacher education ${\circ}$curricular contents and its operations of science teacher education ${\circ}$systems for in-service teacher training and its operations ${\circ}$analyses of problems associated with science teacher education and in-service teacher training. In order to fulfill these objectives this study used methods of literature review, survey, and interviews. The major findings are as follow: ${\circ}$curricular hours of subject matter education are not sufficient for competent science teacher. opportunities for self-training in major are as are seldom given to the most of the science teachers ${\circ}$systematic organization for in-service traings is in urgert need. In addition to there-findings strategies for improving science teacher education and in-service trainings are suggested in this paper.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.137-151
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• 2008

This paper deals with two shops dealing with single perishable product the fresh items are sold at a list price in the primary shop and the unsold items that have reached a certain allowed age are transferred to the secondary shop to be sold at a discounted price. It is assumed that the demand rates in two shops are Independent each other and can be expressed as a function of inventory level and price. With the objective of maximizing the profit under a Last-In-first-Out. (LIFO) issuing policy, we develop mathematical models for the following two cases : (1) opening primary shop only and (2) opening both primary shop and secondary shop. There are three decision variables, i.e., the reduced price in the secondary shop, the allowed age at the primary shop, and the order quantities at the primary shop. A solution procedure is developed based on tabu search and its validity is illustrated through a comparative study.

• Asian Journal of Innovation and Policy
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• v.4 no.1
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• pp.76-102
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• 2015

Drawing upon the resource-based-view of a firm, we investigate the moderating role of operations efficiency on the link between environmental and financial performance. Extant literature has highlighted that operations efficiency is closely associated with the environmental/financial performance of firms, but no empirical study has investigated how operations efficiency affects the link between environmental and financial performance. We argue that operations efficiency could act as a moderator of this relationship. To test the hypothesized relationships, we have used available secondary quantitative UK data, namely data on the environmental/financial performance of Britain's most admired companies. By employing moderated regression analysis, we have found strong evidence for the moderating impact of operations efficiency. Our results are useful to managers in that they show that improvements in operations efficiency in a company can also help improve environmental/financial performance and vice versa.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.983-989
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• 2005

Secondary batteries with high performance are essential in widespread use of modern portable devices such as cellular phones and laptop computers. High energy density, long cycle life, and safety are some of important requirements for secondary battery. To achieve such characteristics, a mixing proportion of electrolyte solution ingredients in the battery should be carefully chosen. In this paper, using statistical design of mixture experiments (DOME), we attempt to find an optimum condition of designing the secondary battery. DOME has a distinct feature in that the experimental region is represented by simplex, rather than hypercube, because the sum of blend proportions should be unity. Several designs based upon this point have been proposed for mixture experiments. Among them, an extreme vertices design is employed in this paper because there are a couple of blend constraints to be considered. In order to investigate how the mixing proportion interacts with other manufacturing factors, a fractional factorial design is also included across the extreme vertices design. As a result, we find that the blend proportion of solution ingredients has a significant effect on battery performances. By simultaneously optimizing two battery capacities, this paper proposes an optimum blend proportion according to process factor settings.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.584-590
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• 2015

Objectives: The purpose of this study was to evaluate quartz concentrations in airborne total and respirable dusts. Materials: Respirable dust samples were collected using a 10 mm aluminum cyclone equipped with a 37 mm$5{\mu}m$ pore size PVC filter. Total dust samples were collected with a three stage cassette from three work sections at earthwork sites located in the South Chungcheong-do Province area. Results: The geometric means of quartz concentrations were $0.008mg/m^3$ and $0.004mg/m^3$ in total dust and respirable dust, respectively. The geometric means of quartz contents analyzed by FTIR were 3.74% in total dust and 3.16% in respirable dust. The geometric mean of quartz concentrations and contents in secondary blasting operations were higher than those in other operations. Conclusions: Given that secondary blasting operations had higher quartz concentrations, there is a need to reduce respirable dust, such as through wet operations.