• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1520-1529
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• 2013

In this paper, we propose and assess the performance of "H infinity filter ($H_{\infty}$, HIF)" and "cost reference particle filter (CRPF)" in the problem of tracking a target based on the measurements of the range and the bearing of the target. HIF and CRPF have the common advantageous feature that we do not need to know the noise statistics of the problem in their applications. The performance of the extended Kalman filter (EKF) is also compared with that of the proposed filters, but the noise information is perfectly known for the applications of the EKF. Simulation results show that CRPF outperforms HIF, and is more robust because the tracking of HIF diverges sometimes, particularly when the target track is highly nonlinear. Interestingly, when the tracking of HIF diverges, the tracking of the EKF also tends to deviate significantly from the true track for the same target track. Therefore, CRPF is very effective and appropriate approach to the problems of highly nonlinear model, especially when the noise statistics are unknown. Nonetheless, HIF also can be applied to the problem of timevarying state estimation as the EKF, particularly for the case when the noise statistcs are unknown. This paper provides a good example of how to apply CRPF and HIF to the estimation of dynamically varying and nonlinearly modeled states with unknown noise statistics.

• Industrial Engineering and Management Systems
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• v.13 no.4
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• pp.369-382
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• 2014

This paper introduces a new multi-product multi-period multi-objective aggregate production planning problem. The proposed problem is modeled using multi-objective mixed-integer mathematical programming. Three objective functions, including minimizing total cost, maximizing customer services level, and maximizing the quality of end-product, are considered, simultaneously. Several constraints such as quantity of production, available time, work force levels, inventory levels, backordering levels, machine capacity, warehouse space and available budget are also considered. Some parameters of the proposed model are assumed to be qualitative and modeled using fuzzy sets. Then, a fuzzy goal programming approach is proposed to solve the model. The proposed approach is applied on a real-world industrial case study of a color and resin production company called Teiph-Saipa. The approach is coded using LINGO software. The efficacy and applicability of the proposed approach are illustrated in the case study. The results of proposed approach are compared with those of the existing experimental methods used in the company. The relative dominance of the proposed approach is revealed in comparison with the experimental method. Finally, a data dictionary, including the way of gathering data for running the model, is proposed in order to facilitate the re-implementation of the model for future development and case studies.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• Journal of Technology Innovation
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• v.25 no.4
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• pp.17-45
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• 2017

This article reviews studies on the societal challenge and technological innovation. Technological innovation in response to social problems is a relatively recent topic of Innovation Studies. Socially-oriented innovations and policies are different in terms of the goals, innovation processes, and ecosystems when compared with industrial innovation. This study examines the existing research that discusses science and technology innovation from the viewpoint of solving societal problems and discusses the direction of future research. This paper presents major research issues on the characteristics of innovation in societal problem solving, innovation governance, roles and ecosystem of innovators, and relationship between societal problem solving policies and other policies.

• Journal of Korean Academy of Nursing
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• v.40 no.2
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• pp.161-171
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• 2010

Purpose: The purpose of the study was to identify the prevalence, risk factors and clinical meanings of geriatric foot problems and to suggest implications for the future. Methods: One hundred eighty nine elderly aged 60 and over from institution as well as community were investigated for their foot conditions by means of a questionnaire including general characteristics, self care capacity, risk factors, foot problem checklist, X-ray, podoscopy and foot scan. Descriptive statistics and $\chi^2$-test was performed as appropriate utilizing SPSS version 14. Less than .05 of p-value was adopted as statistical significance level. Results: All subjects had at least one kind of foot problem and the most prevalent ones were nail problems, foot deformities in order. Prevalence of foot pain and edema was relatively low. Conclusion: Foot problem in elderly is prevalent and geriatric foot is expected to emerge as one of the most important problems in the geriatric field. Therefore strategies to deal with geriatric foot should be developed and practiced for better quality of life in later life.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3329-3350
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• 2017

Installing caching and computing facilities in mobile edge networks is a promising solution to cope with the challenging capacity and delay requirements imposed on future mobile communication systems. The problem of optimal facility placement in mobile edge networks has not been fully studied in the literature. This is a non-trivial problem because the mobile edge network has a unidirectional topology, making existing solutions inapplicable. This paper considers the problem of optimal placement of a fixed number of facilities in a mobile edge network with an arbitrary tree topology and an arbitrary demand distribution. A low-complexity sequential algorithm is proposed and proved to be convergent and optimal in some cases. The complexity of the algorithm is shown to be $O(H^2{\gamma})$, where H is the height of the tree and ${\gamma}$ is the number of facilities. Simulation results confirm that the proposed algorithm is effective in producing near-optimal solutions.

• The Korean Journal of Emergency Medical Services
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• v.16 no.1
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• pp.31-51
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• 2012

Purpose: This study was to develop PBL packages geared toward fostering the problem-solving ability, self-directed learning capability and communicative competence of emergency medical technician students and to give some suggestions on the development of PBL packages of the approach based on the evaluation results of the packages by experts. Methods: First, real clinical situations that learners would be exposed to after graduation should be provided as examples when the packages are developed. Second, a variety of learning-facilitating tools should be offered to facilitate their understanding, because they don't yet gain plenty of clinical practice experiences. Third, they should be encouraged to have an energetic discussion in small group when the developed packages are applied. Conclusion: First, the packages developed in this study were just incorporated into some areas of a single course. In the future, the integration of an entire course or the development of a new course is required to attain the multiple learning objectives in the provided clinical situations. Second, this study attempted to develop the PBL packages to boost the problem-solving ability, self-directed learning capability and communicative competence of emergency medical technician students, and follow-up research should be implemented to finalize the packages based on the suggestions of the experts who evaluated them and to determine the effects of the packages.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.172-180
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• 2013

We herein consider a stochastic multi-item inventory management problem in which a warehouse sells multiple items with stochastic demand and periodic replenishment from a supplier. Inventory management requires the timing and amounts of orders to be determined. For inventory replenishment, trucks of finite capacity are available. Most inventory management models consider either a single item or assume that multiple items are ordered independently, and whether there is sufficient space in trucks. The order cost is commonly calculated based on the number of carriers and the usage fees of carriers. In this situation, we can reduce future shipments by supplementing items to an order, even if the item is not scheduled to be ordered. On the other hand, we can reduce the average number of items in storage by reducing the order volume and at the risk of running out of stock. The primary variables of interest in the present research are the average number of items in storage, the stock-out volume, and the number of carriers used. We formulate this problem as a multi-objective optimization problem. In a numerical experiment based on actual shipment data, we consider the item shipping characteristics and simulate the warehouse replenishing items coordinately. The results of the simulation indicate that applying a conventional ordering policy individually will not provide effective inventory management.

• Journal of Korean Academy of Nursing
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• v.35 no.5
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• pp.787-797
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• 2005

Purpose: The purpose of this study was to examine the effects of problem solving nursing counseling and walking exerciseon weight loss, cardiovascular risk factors, and self-efficacy of diabetic control among obese diabetic patients. The Polar heart rate monitor was used for walking exercise to utilize the Biofeedback mechanism. Method: Fifty nine diabetic patients were conveniently placed into experimental (n=35) and control groups (n=24). The experimental group participated inweekly nursing counseling for 12 weeks and was encouraged to do walking exercise using a Polar monitor. The control group remained in the same treatment as before. The data wascollected from November 2003 to August 2004 and analyzed using t-tests and ANCOVAs. Results: After 12 weeks, the participants in the experimental group reported significantly decreased body weight (p=.004) and total scores on the Parma scale (p=.00l). While the participants in the control group reported significantly increased levels of blood triglyceride (p=.046) and HDL (p=.018). Conclusion: Based on the findings, we concluded that problem focused nursing counseling with intensified walking exercise could reduce the risk of cardiovascular complications and body weight among obese diabetic patients. Future research to explore the long-term effects of nursing counseling on diabetic complications is warranted.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.231-242
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• 1999

The focus of this development program is to input multimedia materials into learning according to the trend of recent social changes and to maximize the learning effect for improving problem-solving by offering familiar teaching materials. The expecting effects of this study are as follows: 1. This program helps students acquire mathematical concepts and principles about circular equation through concrete examples using a variety of media - text, voice, sound, and animation and so on - , makes it possible individual learning which was difficult for students to expect at the existing multitude class as progressing learning each unit on the screen and the perfect learning by offering FEED BACK 2. This program varied the difficulty of learning contents to learn according to learning abilities of learners by using animation and making the most of merits of computer and was able to improve learning effect by studying in a mutual way with managing learning procedure nonsuccessively. 3. Class using CAI program about developed circular equation unit has a positive effect on improving problem-solving by becoming from teacher centered class to student centered one. 4. This program makes students understand the contents of auxiliary learning in multimedia computer more efficiently, and cultivate abilities to adopt in accordance with changes in the future society by forming familiar computer mind.