• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.37-46
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• 2005

To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.4
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• pp.329-334
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• 2017

The structures, which are made up with the huge number of degrees-of-freedom and the assembly of substructures, have a great complexity. In order to increase the computational efficiency, the analysis models have to be simplified. Many substructuring techniques have been developed to simplify large-scale engineering problems. The techniques are very powerful for solving nonlinear problems which require many iterative calculations. In this paper, a modal derivatives-based model order reduction method, which is able to capture the stretching-bending coupling behavior in geometrically nonlinear systems, is adopted and investigated for its performance evaluation. The quadratic terms in nonlinear beam theory, such as Green-Lagrange strains, can be explained by the modal derivatives. They can be obtained by taking the modal directional derivatives of eigenmodes and form the second order terms of modal reduction basis. The method proposed is then applied to a co-rotational finite element formulation that is well-suited for geometrically nonlinear problems. Numerical results reveal that the end-shortening effect is very important, in which a conventional modal reduction method does not work unless the full model is used. It is demonstrated that the modal derivative approach yields the best compromised result and is very promising for substructuring large-scale geometrically nonlinear problems.

• Journal of the Korea Society for Simulation
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• v.21 no.1
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• pp.55-68
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• 2012

Recently it is important to understand service supply chain because the economy moves from manufacturing to services. However, most of existing supply chain research focuses exclusively on the manufacturing sector. To overcome this situation, it needs to investigate and analyze service supply chain. Simulation is one of the most frequently used techniques for analysis and design of complex system. Service supply chain is complex and large systems that require an accurate designing phase. Especially, it is important to examine closely the dynamically interactive behavior of the different service supply chain components in order to predict the performance of the servcie supply chain. In this paper, we develop a conceptual model of service supply chain. Then, we present a new procedure to develop simulation model for the developed conceptual model of service supply chain, based on the UML analysis and design tools and on the ARENA simulation language. The two main characteristics of the proposed procedure are the definition of a systematic procedure to design service supply chain and of a set of rules for the conceptual model translation in an ARENA simulation language. The goal is to improve the knowledge on service supply chain management and support the simulation model development efficiency on service supply chain.

• Korean Journal of Community Nutrition
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• v.22 no.4
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• pp.307-322
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• 2017

Objectives: This study examined the effects of nutrition education focused on personalized daily energy requirement and food units using Food Exchange System on anthropometric, biochemical characteristics, nutrition knowledge, dietary attitude and nutrient intakes for overweight and obese in a public health center. Methods: The subjects were 60 overweight/obese women based on BMI (educated 30 vs. non-educated 30, 50~64 years). Educated group was provided individual and/or group lessons (40 min/lesson/week, 5 week), 'Introduction: obese & health', '6 nutrients and 6 food groups', 'My obesity & daily needed energy', 'Meal planning for personalized daily energy and food units using Food Exchange Systems', and 'Smart food choices'. After education, we examined the differences in anthropometric/biochemical characteristics, nutrition knowledge, dietary attitude and nutrient intakes between educated group and non-educated group. Results: After nutrition education, in the educated group, there were improvements on anthropometric/biochemical characteristics, nutrition knowledge, dietary attitude and nutrient intakes in the educated group compared to the non-educated group. We observed a decrease in the mean weight, total cholesterol (TC) and the incidence of overweight/obesity and hypercholesterolemia and an increase in the mean lean body mass. The scores of nutrition knowledge, 'Function of carbohydrate, protein, vitamin, mineral' and 'Food Sources of fat, vitamin, mineral' were increased. The scores of dietary attitudes, 'Taking a joyful meal, a leisurely meal, a balanced meal, a meal with sufficient vegetables, a meal with diversity, a meal with spicy foods, a meal with overeating' were increased. The intakes of energy, carbohydrate, fat, protein, vitamin A, thiamin, Zn and cholesterol were decreased. The scores of INQ, protein, vitamin A, vitamin C, thiamin, riboflavin, vitamin B6, folate, Ca, P, Fe, Zn were increased. Conclusions: The nutrition education focused on personalized daily energy requirement and food exchange unit using Food Exchange System for overweight and obese may improve food behavior, dietary intakes and symptoms of overweight and obese, even in a community health center.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.72-77
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• 2010

The Incheon Bridge, which was opened to the traffic in October 2009, is an 18.4 km long sea-crossing bridge connecting the Incheon International Airport with the expressway networks around the Seoul metropolitan area by way of Songdo District of Incheon City. This bridge is an integration of several special featured bridges and the major part of the bridge consists of cable-stayed spans. This marine cable-stayed bridge has a main span of 800 m wide to cross the vessel navigation channel in and out of the Incheon Port. In waterways where ship collision is anticipated, bridges shall be designed to resist ship impact forces, and/or, adequately protected by ship impact protection (SIP) systems. For the Incheon Bridge, large diameter circular dolphins as SIP were made at 44 locations of the both side of the main span around the piers of the cable-stayed bridge span. This world's largest dolphin-type SIP system protects the bridge against the collision with 100,000 DWT tanker navigating the channel with speed of 10 knots. Diameter of the dolphin is up to 25 m. Vessel collision risk was assessed by probability based analysis with AASHTO Method-II. The annual frequency of bridge collapse through the risk analysis for 71,370 cases of the impact scenario was less than $0.5{\times}10^{-4}$ and satisfies design requirements. The dolphin is the circular sheet pile structure filled with crushed rock and closed at the top with a robust concrete cap. The structural design was performed with numerical analyses of which constitutional model was verified by the physical model experiment using the geo-centrifugal testing equipment. 3D non-linear finite element models were used to analyze the structural response and energy-dissipating capability of dolphins which were deeply embedded in the seabed. The dolphin structure secures external stability and internal stability for ordinary loads such as wave and current pressure. Considering failure mechanism, stability assessment was performed for the strength limit state and service limit state of the dolphins. The friction angle of the crushed stone as a filling material was reduced to $38^{\circ}$ considering the possibility of contracting behavior as the impact.

• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.19-34
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• 2008

IT investment is usually very costly and takes a long time to get the results out of investment. However, most of currently available evaluation methods for IT investment are based upon short-term effects, hence their results are not fully trustworthy. In addition, those methods commonly consider only financial aspects such as ROI. For more reliable evaluation, it is necessary to consider non-financial factors such as system utilization, customer satisfaction, public relations, and so on, as well as financial factors. In this research, we propose an evaluation method that can evaluate both financial and non-financial aspects on a long-term base. For this purpose, we employed the research results developed in System dynamics and Balanced scorecard. System dynamics is useful in analyzing long term behavior of a given system, and Balanced scorecard is useful for evaluating both financial and non-financial aspects. We demonstrated the usefulness of our method by applying it to the evaluation of RFID (Radio Frequency Identification) investment in a distribution and retail industry. From this application, we found that RFID investment may not be rewarding in the short term, but is sure to be returning the income relative to its investment in the long run.

• Korean Security Journal
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• no.29
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• pp.35-57
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• 2011

While demands on private securities have been increase, expectations on the service quality as compensation for the investment expensive is also rising. However, private security services are in situations of not satisfying various customer's needs owing to insufficient special manpower, capital, and skills in spite of expected high-quality services toward customers. Therefore, this study aims to find out the causality between private security enterprises and relationship characteristics, purchasing behaviors of customers, and then searching for a marketing strategy that can provide best services to the enterprises that are confronting to limitless competitive systems by grasping customer's needs and necessities. For achieving this goal, the study objected to shop employees using private security enterprises after diving Cheonan City of South Chungcheong Province into South, East and East, West, and then collected 236 persons by using the convenience sampling. Regarding to research tools, this study used questionnaire having been recomposed based on previous researches home and abroad, and frequency analysis, reliability analysis, factor analysis, correlation analysis, and regression analysis were carried out data was treated by treatments by using SPSS version 18.0 statistic package for treating the data. Through above research methods and procedures, results could be gotten same as followings. First, correlations between private security enterprise's relationship characteristics and purchasing behaviors showed positive (+) relations, and the latter was increased as much as relationship characteristics were high. Second, as the result of analyzing correlations between private security enterprise's relationship characteristics and purchasing behaviors, reputation, physical features, and communication affected influences to word of mouth activities. Third, reputation and communication affected to repeated purchasing behaviors as the result of analyzing private security's relationship characteristics and repeat purchasing behaviors.

• Polymer(Korea)
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• v.33 no.1
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• pp.26-32
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• 2009

The aim of this research was to prepare microparticulate systems based on poly (lactide-co-glycolide)(PLGA) for the local release of ipriflavone in order to reduce bone loss. We developed the IP loaded PLGA microspheres using relatively simple oil-in-water(O/W) solvent evaporation method. HPLC was used to perform the in vitro release test of IP and morphology of cell attached on the micro-spheres was investigated using SEM. Cytotoxicity was assayed by cell counting kit-8 (CCK-8) test. Osteogenic differential cells were analyzed by ALP activity. Through RT-PCR analysis, we observed osteocalcin, ALP, and Type I collagen mRNA expression. The release of IP in vitro was more prolonged over 42 days and IP/PLGA microspheres showed the improvement on the cell proliferation, ALP activity and RT-PCR comparing with control (only PLGA). This initial research will be used to direct future work involved in developing this composite injectable bone tissue engineering system.

• Journal of Distribution Science
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• v.4 no.2
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• pp.21-40
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• 2006

Small and middle sized Franchise system channels experience conflicts because of constant interaction between franchiser and franchisee. However, it is rarely that attempt has been made to identify causes of conflicts in distribution of franchise industry. The purpose of this study was to explore cause of conflicts from the franchisee. For the study, data were collected from the owner or the shop-manager with a contractor in franchise systems. By means of in-depth interviews with multiple informants, their statement was analyzed qualitatively. From analysis of the resulting data, the causes of conflicts were associated with two broad sets, attitudinal and structural differences between franchisers and franchisees. First, attitudinal sources of conflict were identified as perception of subordinated relationships between channel members, delayed announcement on order changes, difficulties in communication by doing irresponsible behavior, different expectations between channel members in market territory and lack of consistent-supporting. Second, structural sources of conflict involved unilateral decision on interior, payment method, unreasonable delivery issue, treat franchisee with discrimination by the sales, in controlling against free management. There are limitations on generalization due to the results based on interview, but this study will be a useful exploratory step before designing a large scale survey.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.4
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• pp.95-102
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• 2016

Computer security incident such as confidential information leak and data destruction are constantly growing and it becomes threat to information in digital devices. To respond against the incident, digital forensic techniques are also developing to help digital incident investigation. With the development of digital forensic technology, a variety of forensic artifact has been developed to trace the behavior of users. Also, a diversity of forensic tool has been developed to extract information from forensic artifact. However, there is a issue that information from forensic tools has its own forms. To solve this problem, it needs to process data when it is output from forensic tools. Then it needs to compare and analyze processed data to identify how data is related each other and interpret the implications. To reach this, it calls for effective method to store and output data in the course of data processing. This paper aims to propose DFIOC (Digital Forensic Indicators Of Compromise) that is capable of transcribing a variety of forensic artifact information effectively during incident analysis and response. DFIOC, which is XML based format, provides "Evidence" to represent various forensic artifacts in the incident investigation. Furthermore, It provides "Forensic Analysis" to report forensic analysis result and also gives "Indicator" to investigate the trace of incidence quickly. By logging data into one sheet in DFIOC format for forensic analysis process, it is capable of avoiding unnecessary data processing. Lastly, since collected information is recorded in a normalized format, data input and output becomes much easier as well as it will be convenient to use for identification of collected information and analysis of data relationship.