• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.26-35
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• 2007

The vehicle of urban transit is a complex system that consists of various electric, electronic, and mechanical equipments, and the maintenance cost of this complex and large-scale system generally occupies sixty percent of the LCC (Life Cycle Cost). For reasonable establishing of maintenance strategies, safety security and cost limitation must be considered at the same time. The concept of system reliability has been introduced and optimized as the key of reasonable maintenance strategies. For optimization, three preceding studies were accomplished; standardizing a maintenance classification, constructing RBD (Reliability Block Diagram) of VVVF (Variable Voltage Variable Frequency) urban transit, and developing a web based reliability evaluation system. Historical maintenance data in terms of reliability index can be derived from the web based reliability evaluation system. In this paper, we propose applying inverse problem analysis method and hybrid neuro-genetic algorithm to system reliability optimization for using historical maintenance data in database of web based system. Feed-forward multi-layer neural networks trained by back propagation are used to find out the relationship between several component reliability (input) and system reliability (output) of structural system. The inverse problem can be formulated by using neural network. One of the neural network training algorithms, the back propagation algorithm, can attain stable and quick convergence during training process. Genetic algorithm is used to find the minimum square error.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.5969-5973
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• 2012

Introduction: Andhra Pradesh (AP) is one of the largest tobacco producing states in India. About 29% of adults in AP currently use tobacco in some form. Almost 24% of males and 4% of females are smokers. The prevalence of tobacco use in the state is higher than the national average of 15% for male and 2% for female smokers. However, few attempts have been made to understand the current situation of tobacco control resources, activities and strategies in the context of such a high tobacco prevalence state. The present study aimed to identify the gaps in existing tobacco control program and areas where tobacco control efforts can be integrated. Methods: Data were collected using both quantitative and qualitative methods. Semi-structured interviews were undertaken with a total of 95 key officials of state health departments, program managers, and project directors in six districts to understand ongoing tobacco control efforts. To facilitate the interviews, semi-structured guides were developed. Simple descriptive statistical analysis was conducted on the quantitative data using SPSS version 17. Results: The results of the situational analysis suggest that a sufficient health workforce and infrastructure with the potential to integrate tobacco control activities is available in the surveyed districts. However, lack of integration of the tobacco control program intothe tuberculosis control program and the National Rural Health Mission was observed. Information, education and communication activities were lacking at block level health facilities. Conclusions: Our findings indicate that lack of trained health professionals, paucity of dedicated funds, lack of information, education and communication materials and low priority given to tobacco control activities are some of the factors which impede integration of tobacco control into existing health and developmental programmes in the districts of Andhra Pradesh, India.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.23-29
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• 2015

The baby-step giant-step algorithm seeks b in a discrete logarithm problem when a,c,p of $a^b{\equiv}c$(mod p) are already given. It does so by dividing p by m block of $m={\lceil}{\sqrt{p}}{\rceil}$ length and letting one giant walk straight toward $a^0$ with constant m strides in search for b. In this paper, I basically reduce $m={\lceil}{\sqrt{p}}{\rceil}$ to p/l, $a^l$ > p and replace a giant with an adult who is designed to walk straight with constant l strides. I also extend the algorithm to allow $2^k$ adults to walk simultaneously. As a consequence, the proposed algorithm quarters the execution time of the basic adult-walk method when applied to $2^k$, (k=2) in the range of $1{\leq}b{\leq}p-1$. In conclusion, the proposed algorithm greatly shorten the step number of baby-step giant-step.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.4 s.346
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• pp.38-48
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• 2006

In this paper, we developed a hardware architecture of Reed-Solomon RS(255,239) decoder for the DMB mobile terminals. The DMB provides multimedia broadcasting service to mobile terminals, hence it should have small dimension for low power and short decoding delay for real-time processing. We modified Euclid algorithm to apply it to the key equation solving which is the most complicated part of the RS decoding. We also designed a small finite field divider to avoid the use of large Inverse-ROM table, and it consumed 17 clocks. After synthesis with Synopsis on Samsung STD130 $0.18{\mu}m$ Standard Cell library, the Euclid block had 30,228 gates and consumed 288 clocks, which gave the 25% reduced area compared to other existing designs. The size of the entire RS decoder was about 45,000 gates.

• The Journal of the Korean dental association
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• v.48 no.1
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• pp.6-11
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• 2010

Amid the rapid transitions in both local and international markets, the Korean dental industry is facing more challenges than at any time in its history. This paper tried to address some of the key issues faced by the industry as well as the policy issues and I direction of implementation that the Korean Dental Association (KDA) is expected to tackle. First, the direction of reforming the country's health insurance system was examined with emphasis on the expected changes in and improvement of the fee-for-service reimbursement system (FFSRS) and medical reimbursement system (MRS). With FFSRS, the most urgent issue would be ameliorating the current lop-sided, unreasonable reimbursement system that prevents suppliers from voicing their opinions. To help achieve that goal, the limited authority and responsibility of the president of National Health Insurance Corporation (NHIC) as one of the contract-making parties must be clarified. In addition, the functions of NHIC's Health Insurance Finance Committee must be restricted; at the same time, the panel organization of the Health Insurance Policy Review Committee needs to be reformed to embrace greater democracy. As with MRS, the government is considering a block budget bill to help promote efficiency in employing and managing the health insurance fund. Policymakers must understand that the implementation of such proposal could exacerbate an already dire situation. Improving MRS requires meeting the following preconditions: (a) the structurally vicious cycle of small charge-small salary needs to be resolved, and a certain percentage of fee raise must be guaranteed on a yearly basis to help adjust the fee system to a more realistic level; (b) the supply-and-demand balance in producing health care professionals must be improved including the prevention of oversupply of doctors, nurses, etc., and; (c) institutional strategies must be provided to enhance the quality of medical care and ensure academic advancement in health care disciplines.

• Journal of Korea Multimedia Society
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• v.9 no.2
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• pp.172-188
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• 2006

Sensor localization is one of the fundamental problems in wireless sensor networks. Previous localization algorithms can be classified into two categories, the GGB (Global Geometry-Based) approaches and the LGB (Local Geometry-Based). In the GGB approaches, there are a fixed set of reference nodes of which the coordinates are pre-determined. Other nodes determine their positions based on the distances from the fixed reference nodes. In the LGB approaches, meanwhile, the reference node set is not fixed, but grows up dynamically. Most GGB algorithms assume that the nodes are deployed in a convex shape area. They fail if either nodes are in a concave shape area or there are obstacles that block the communications between nodes. Meanwhile, the LGB approach is vulnerable to the errors in the distance estimations. In this paper, we propose new localization algorithms to cope with those two limits. The key technique employed in our algorithms is to determine, in a fully distributed fashion, if a node is in the line-of-sight from another. Based on the technique, we present two localization algorithms, one for anchor-based, another for anchor-free localization, and compare them with the previous algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1257-1263
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• 2018

Secure authentication technology is a fundamental building block for secure services for Internet of Things devices. Particularly, the multiplication operation is a core operation of public key cryptography, such as RSA, ECC, and SIDH. However, modern low-power processor, namely ARM Cortex-M3 processor, is not secure enough for practical usages, since it executes the multiplication operation in variable-time depending on the input length. When the execution is performed in variable-time, the attacker can extract the password from the measured timing. In order to resolve this issue, recent work presented constant-time solution for multiplication operation. However, the implementation still missed various speed-optimization techniques. In this paper, we analyze previous multiplication methods over ARM Cortex-M3 and provide optimized implementations to accelerate the speed-performance further. The proposed method successfully accelerates the execution-time by up-to 25.7% than previous works.

• Smart Media Journal
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• v.3 no.4
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• pp.16-21
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• 2014

HEVC is the latest joint video coding standard with ITU-T SG16 WP and ISO/IEC JTC1/SC29/WG11. Its coding efficiency is about two times compared to H.264 high profile. Intra prediction has 35 directional modes including dc and planer. However an accurate mode decision on lots of modes with SSE is too costly to implement it with hardware. The key idea of this paper is a DCT shared architecture to reduce the complexity of HEVC intra encoder. It is to use same DCT block to quantize as well as to calculate SSE in RDO. The proposed intra encoder uses two step mode decision to lighten complexity with simplified RDO blocks and shares the transform resources. Its BD-rate increase is negligible at 20% on hardware aspect and the operating clock frequency is 300MHz@60fps on FHD ($1920{\times}1080$) image.

• International Journal of Contents
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• v.5 no.4
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• pp.81-87
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• 2009

In the midst of a continued discourse and development concerning design education and its impact on innovation and creativity, I believe that design education still holds the key to enhancing design methodology while increasing creativity by having students take on several creative roles in an interactive and enjoyable studio course. Clearly, there exist impediments that block the creative process in our standard track in design education; however, a course entitled "The Creative Workshop" can overcome such obstacles. Through this course, a student can learn the essential skills of a designer: inventive thinking, a sense of aesthetics, and a spirit of collaboration. In addressing each of the three essential elements, this course has devised role-plays in the way of projects. Simply put, students will be required to demonstrate and, therefore, express their unique creativity that may have otherwise gone muted. Such creative expression can take form in a low stakes, open forum that heralds the invaluable attribute in design such as creative freedom. As a result, the true spirit of creativity is fostered rather than mere aesthetics and styling. Moreover, through role plays, the focus shifts its center from design, allowing each student to explore the uncharted areas of one's own creativity which may come naturally to some extend while disconcerting to others. It may prove particularly uncomfortable for Korean students whose ideas about education have been directly connected to the strict and regimented school system that stresses adherence to standardization such as the national college entrance exam. This course, therefore, is aimed stretch the scope and scale of students' creativity as they learn to collaborate on role plays, utilizing diverse skills from various disciplines.

• Journal of the Korean School Mathematics Society
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• v.22 no.3
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• pp.257-275
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• 2019

Technology-based convergence education is being emphasized for students in the era of the fourth industrial revolution. In math education, students need to increase their capabilities in the future by having them experience mathematical problems using robots and sensors, a key technology in the era of the fourth industrial revolution. To this end, it is necessary to present educational uses for educational robots in relation to math and curriculum from a 'mathematics education perspective' and analyze its educational use in relation to the mathematics and curriculum, considering the role of mathematics at the base of the process of exploring real-world phenomena and solving problems. Based on the analysis of Van Hiele levels of development in geometry and the LOGO activity level of Olson et al.(1987), this study analyzed and presented the level of LEGO Mindstorm activity, a representative educational Robot capable of collecting and analyzing data and programming in the form of block language, in the first to fourth level.