• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.19-32
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• 2005

It is shown that the problem of minimizing (maximizing) a quadratic cost functional (quadratic gain functional) given the dynamics dx = (fx + gu)dt + hdb(t, a) where b(t, a) is a fractional Brownian motion of order a, 0 < 2a < 1, can be solved completely (and meaningfully!) by using the dynamical equations of the moments of x(t). The key is to use fractional Taylor's series to obtain a relation between differential and differential of fractional order.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.477-477
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• 2000

A multifunctional sensor is designed to measure viscosity, cleanness, temperature and capacitance of engine oil to make a clear decision on its condition. The simple structure helps easy fabrication and low cost while measuring four parameters by one sensor. The operation is described theoretically and is supported by experimental data. A fuzzy based algorithm to fuse the four kinds of data from multi-functional sensor in order to make a decision on the best time to change the oil is proposed.

• Journal of Applied Reliability
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• v.1 no.1
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• pp.9-15
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• 2001

This paper modelled the fail-safe control logic through the frequency coding input and designed the 3-out of-6 self checker using the error detect coding method of information redundancy. In addition, this paper also peformed the reliability parallel numeric analysis regarding single module between fail-safe. control logic module and TMR(Triple Modular Redundancy), therefore, we achieved the result that the fail-safe control logic increases a functional reliability because of decreasing system waste cost and functional overhead rather than the existing hardware redundancy method.

• Journal of Distribution Science
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• v.12 no.8
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• pp.123-132
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• 2014

Purpose - Recently, Korean companies have been struggling to perform well in the larger smartphone market in China, which is regarded as a blue ocean area. First, it is very important to accurately understand the Chinese consumers, who have a different consumption culture and value system from the Korean culture and system. This would help to identify priorities for the Chinese market. Further, considering the smartphone industry, where technological change is rapid, Korean companies will need to take prompt measures about market trends in order to establish strong competitiveness. Consequently, this study focused on analyzing the relationship between the variables of consumption value, satisfaction, and loyalty in the Chinese smartphone market. The principal dimensions of consumption value, which smartphones have, was analyzed, and the influence on satisfaction was identified. Moreover, the relationship among the variables of satisfaction, attitudinal loyalty, and behavioral loyalty was empirically analyzed. Research design, data, and methodology - This study examined the relationships between various consumption values (functional value, emotional value, social value, epistemic value, and economic value), along with satisfaction and loyalty. The data were collected through a questionnaire survey that was circulated to 310 customers who were users of smartphones in Chingdao and Yeontae regions in China. The survey was conducted from June 23 to August 4, 2013. A total of 301 responses to the questionnaires were collected and used for the data analysis. Moreover, a path analysis based on Lisrel 8.54 was used for the hypothesis test. Results - The variables of functional value, emotional value, social value, and epistemic value were revealed to have positive effects on satisfaction related to smartphone usage. However, the variables of monetary cost and psychological cost were not found to have negative effects on satisfaction related to smartphone usage. Moreover, satisfaction positively influenced attitudinal loyalty related to smartphone usage, but did not have a significant influence on behavioral loyalty related to smartphone usage. Specifically, satisfaction is essential, but not a sufficient condition for building behavioral loyalty in relation to smartphone usage. In addition, attitudinal loyalty positively influenced behavioral loyalty in relation to smartphone usage. Conclusions - First, this study shows that functional value, emotional value, social value, and epistemic value in relation to smartphone usage are important for marketing in the Chinese smartphone market. Particularly, functional value and emotional value play pre-eminent roles as regards customer loyalty in the use of smartphones. Second, the results of this study reveal that the variables of monetary cost and psychological cost are not important to the Chinese consumers. Specifically, the smartphone price and cognitive effort are not perceived as value barriers. Third, satisfaction did not guarantee behavioral loyalty in relation to smartphone usage, and the strategic approach for improving the repurchase and referral action in relation to smartphones based on solid attitudinal loyalty would be desirable and should be the focus of the marketing activities of Korean smartphone companies.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.430.2-430.2
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• 2014

Previous studies to enhance optical properties of opto-electronic devices involve patterning of inorganic materials. Patterning of inorganic material usually encompasses vacuum process that hinders productivity and increases cost. In this research, we successfully formed nano patterns with polymer matrix and fabricated photonic crystals. This process is anticipated to increase the performance of opto-electronic devices without any vacuum process. Moreover, nano imprint technology reduces cost and bolsters productivity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.203-209
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• 1993

In Factory Automation environments such as FMS, the formation of machine-part based on GT should be considered. The purpose of this study is to develop a economic heuristic algorithm which considers various elements such as unit processing time, subcontract cost, and functional operation cost, machine processing capacity etc. When this proposed approach is applied to the real situation expected benefits are as follows: the reduction of production lead time work in process, labor force, tooling, rework and scrap, setup time, order time delivery, and paper work, etc.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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• pp.81-92
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• 1995

In this paper, we present a high-level synthesis system that generates area-efficient RT-level datapaths with multiport memories. The proposed scheduling algorithm assigns an operation to a specific control step such that maximal sharing of functional units can be achieved with minimal number of memory ports, while satisfying given constraints. We propose a measure of multiport memory cost, MAV (Multiple Access Variable) which is defined as a variable accessed at several control steps , and overall memory cost is reduced by equally distributing the MAVs throughout all the control steps. Experimental results show the effectiveness of the proposed algorithm. When compared with previous approaches for several benchmarks available from literature, the proposed algorithm generates the datapaths with less memory modules and interconnection structures by reflecting the memory cost in the scheduling process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.249-263
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• 1997

This paper addresses the parts route selection and economic design in flexible manufactuirng system (FMS). Parts are processed through several stage workstations according to operation sequences. The machine of each workstation can do multiple operation functions. And 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 routes of parts, number of machine at each workstation, number of vehicle and makespan time. Two models are suggested. One is assumed that the operation stage of parts can be processed at the only one among several available workstations. Other is assumed that the operation stage of parts is allowed to be processed at several workstations. Parts are transported by automated guided vehicles (AGVs). The decision criteria is to minimize the sum of processing cost, travel cost, setup cost and overhead cost. The formulation of models is represented. A solution algorithm is suggested, and a numerical example is shown.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.113-124
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• 2009

Value-based requirements engineering process, called The ViRE(Value-Innovative Requirement Engineering) was suggested to create an uncontested market using ERRC(Eliminate, Reduce, Raise, Create) requirements analysis. But ViRE did not provides a quantitative data analysis method for ERRC decision so as to make objective decisions for customers. In this paper, to solve this problem, we suggest a quantitative ERRC analysis method by estimating requirements cost. Our method defines user requirements and decides their weight. Then, it makes quality level table for all the identified requirements and function modules and estimate implementation cost based on their quality levels. Finally, assess each requirement's impact and then evaluate ERRC value. We could get the more objective ERRC values by evaluate the requirement weight. functional module weight, and implementation cost. And we proved the efficiency of our model by a case study, smart student ID system.

• Journal of Preventive Medicine and Public Health
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• v.43 no.4
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• pp.352-361
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• 2010

Objectives: This study estimated the annual socioeconomic costs of food-borne disease in 2008 from a societal perspective and using a cost-of-illness method. Methods: Our model employed a comprehensive set of diagnostic disease codes to define food-borne diseases with using the Korea National Health Insurance (KNHI) reimbursement data. This study classified the food borne illness as three types of symptoms according to the severity of the illness: mild, moderate, severe. In addition to the traditional method of assessing the cost-of-illness, the study included measures to account for the lost quality of life. We estimated the cost of the lost quality of life using quality-adjusted life years and a visual analog scale. The direct cost included medical and medication costs, and the non-medical costs included transportation costs, caregiver's cost and administration costs. The lost productivity costs included lost workdays due to illness and lost earnings due to premature death. Results: The study found the estimated annual socioeconomic costs of food-borne disease in 2008 were 954.9 billion won (735.3 billion won-996.9 billion won). The medical cost was 73.4 -76.8% of the cost, the lost productivity cost was 22.6% and the cost of the lost quality of life was 26.0%. Conclusions: Most of the cost-of-illness studies are known to have underestimated the actual socioeconomic costs of the subjects, and these studies excluded many important social costs, such as the value of pain, suffering and functional disability. The study addressed the uncertainty related to estimating the socioeconomic costs of food-borne disease as well as the updated cost estimates. Our estimates could contribute to develop and evaluate policies for food-borne disease.