• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.55-65
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• 2009

Due to the rapid increase of electricity demand, consideration of environmental constraints in optimal power flow (OPF) problems is increasingly important. In Algeria, up to 90% of electricity is produced by thermal generators (vapor, gas). In order to keep the emission of gaseous pollutants like sulfur dioxide (SO2) and Nitrogen (NO2) under the admissible ecological limits, many conventional and global optimization methods have been proposed to study the trade-off relation between fuel cost and emissions. This paper presents an efficient decomposed Parallel GA to solve the multi-objective environmental/economic dispatch problem. At the decomposed stage the length of the original chromosome is reduced successively and adapted to the topology of the new partition. Two subproblems are proposed: the first subproblem is related to the active power planning to minimize the total fuel cost, and the second subproblem is a reactive power planning design based in practical rules to make fine corrections to the voltage deviation and reactive power violation using a specified number of shunt dynamic compensators named Static Var Compensators (SVC). To validate the robustness of the proposed approach, the algorithm proposed was tested on the Algerian 59-bus network test and compared with conventional methods and with global optimization methods (GA, FGA, and ACO). The results show that the approach proposed can converge to the near solution and obtain a competitive solution at a critical situation and within a reasonable time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.287-295
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• 2010

In this paper, we introduce a novel approach to optimization algorithm which is a distributed Mean field Genetic algorithm (MGA) implemented in MPI(Message Passing Interface) environments. Distributed MGA is a hybrid algorithm of Mean Field Annealing(MFA) and Simulated annealing-like Genetic Algorithm(SGA). The proposed distributed MGA combines the benefit of rapid convergence property of MFA and the effective genetic operations of SGA. The proposed distributed MGA is applied to the channel routing problem, which is an important issue in the automatic layout design of VLSI circuits. Our experimental results show that the composition of heuristic methods improves the performance over GA alone in terms of mean execution time. It is also proved that the proposed distributed algorithm maintains the convergence properties of sequential algorithm while it achieves almost linear speedup as the problem size increases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1458-1464
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• 2007

Today, domestic and foreign manufacturing industries have to cope with obsolescence of manufacturing equipment because the shifting market trends drive the rapid changes in the production process resulting in stressful operation. Quality control process for manufacturing and production involves a familiar step - when the production process is completed, every item is subjected to various routine tests to determine that it meets the minimum quality standards. Typically, when a faulty product is found, the production line has to be stopped and the current batch is marked for further inspected and exhaustive testing. In this research, we propose a quality monitoring system for productivity enhancement. Our approach aims to reduces the operational down time in the production line of a car-component factory. The proposed monitoring system for productivity enhancement is designed to collect the data through testing at each phase of the assembly line and uses predictive methods on the collected data to achieve early detection of faults in the production process and minimize the number of products in a faulty batch thus minimizing the losses incurred from defective products. More importantly, this system aims to forecast and proactively detect faults and activate warnings when they are detected thus minimizing items in the defective batch, reducing the damage to manufacturing equipment and ultimately reducing the operational downtime or the delay in the resumption of normal factory operation.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.455-462
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• 2016

Recently, followed by rapid growth of robotics field, multi-linkage mechanism which can even pass by rough road is getting lots of attention. In this paper, I focused on Jansen mechanism. It's a kinematics object which is named after Dutch artist Theo jansen. Jansen mechanism embraces structure and mechanism which creates locomotion with the combination of the power and simple structure. Theo jansen suggests a 'Holy number'. It's an ideal ratio of leg components length. However, if there's desired gait locomotion, you have to adjust the ratio and the length. But even slight change of the length could cause a big change at the end-point. To solve this problem, I suggest a reverse engineering method to get a ratio of each links by nonlinear optimization with pre-set desired trajectory. First, we converted a movement of the joint of Jansen mechanism to vectors by kinematics analysis of multi-linkage structure. And we showed the trajectory at the end-point. After that, we set desired trajectory which we found most ideal. Then we got the length of the leg components which draws a trajectory as same as trajectory we set, using Multi-objective genetic algorithm toolbox in MATLAB. Result is verified by Edison designer and mSketch. And we analyzed if it could pass through the obstruction which is set dynamically.

• The Korean Journal of Pain
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• v.21 no.2
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• pp.131-135
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• 2008

Background: There has recently been a rapid increase in the number of pain clinics and significant advancement in the treatment of pain in Korea. Therefore, this study was conducted to identify possible problems associated with pain clinics and to use this information to help design future pain clinics. This assessment was conducted from the perspective of professional ballet dancers, who are at high risk for pain like other athletes. Methods: One-hundred professional ballet dancers responded to questionnaires designed to ascertain their preference for different types of clinics, the extent of the pain they experience, and their overall opinion of pain clinics. Results: All of the respondents complained of pain in one or more sites and reported that they had visited some type of clinic for treatment at least once. Overall, the respondents preferred using the following methods to treat pain: orthopedic surgery (76 dancers), oriental medicine (49 dancers), and therapy at pain clinic (48 dancers). Fifty-three percent of the 48 dancers who had received treatment at pain clinics were satisfied with their treatment. Forty-four percent of the 52 dancers who had not been treated at a pain clinic had no knowledge of the existence of such facilities. Conclusions: This survey revealed that, although professional ballet dancers have a high prevalence of pain, many have no knowledge of pain clinics. Therefore, efforts should be made by pain clinics to make information regarding their facilities widely available to professional ballet dancers so they can serve the widest range of clientele.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.415-424
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• 2012

Since the Korean War, starvation and severly desperate living conditions hit the whole country. However, Koreans finally overcame such difficulties, achieving the miracle on the Han River. Through rapid industrial developments, Korea would not need any more supports from the outside but rather became a country which would offer a support. Meanwhile, in 1997, the Korean domestic economy underwent IMF which had caused a massive number of unemployeds. Among those people, many began to show interest in D.I.Y woodcraft for a whole new change and eventually, the industry of D.I.Y woodcraft business became expanded. Now, Korea survived I.M.F and was grown as one of the leading countries in the world, having held the G20 summit conference. Such achievements helped national income increased with the domestic GNP of $30,000, having exceeded $20,000. The population also grew to over fifty million and with all these factors, Korea joined the ranks of advanced countries. As a living environment of an individual gets improved and people have had time on their sides due to the five-day workweek, many have been taking this opportunity to engage in self-development and leisure activities. As trends are pursuing eco-friendliness and D.I.Y, D.I.Y woodcraft workshops are opening nationwide. Considering this, as analyzing present conditions of D.I.Y woodcraft workshops, which are being quickly popular at this moment in Korea, this study focuses on presenting a Korean-style D.I.Y woodcraft workshop, suggesting how to promote D.I.Y woodcraft business to be a pivot of the furniture industry in Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.3 s.162
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• pp.463-474
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• 2007

With rapid expansion in e-retailing of apparel business, personalized fitting model service shows the possibility as the differentiated marketing strategy in cyber shopping. According as necessity of personalized fitting model construction rises, it is tried personalized fitting model creation in several fields such as computer engineering, mechanical engineering, information engineering. But, because existent study was concentrated only on human body modeling, it does not reflect average morphological characteristics of human body properly. In this study, we wish to examine if morphing is fit for expressing characteristic of average human body shape and suggest desirable morphing. We used 3-D scan data of 254 Korean middle aged men collected by Size Korea 2004. The result of this study are as follows: Lower body types were categorized by height hip girth and lower drop(hip girth-navel girth) which were main factors of lower body shape. Then each factor was divided into 3 groups respectively, 30% in the middle, over 30%, under 30%. In 27 groups, the group which belonged to 30% in the middle of height, 30% in the middle of hip girth, 30% in the middle of lower drop was selected as a representative group. We tested geometrical figure by differ volume, tilt, position of point. And we created a representative type of men's lower bodies by morphing the representative group and analyzed it's horizontal, vertical sections. A representative type which was created by morphing reflected a real body and changed realistically at the part of hip, crotch, calf muscle and so on. A cross sections of a representative type were similar to average cross sections of the representative group in size and shape. So it was proved that morphing was successful.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.89-99
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• 2007

With the development of the internet technology, network application services based on a large number of network nodes have been focused. However, such application services require much larger network size and traffic than current network. In order to develop them, efficient solutions as well as a simple improvement of network infra processing time are required. In this paper, to contribute a improvement of network computing technology, we design and implement the agent platform software based on the agent technology that performs works independently and asynchronously on a network and platform. The proposed agent platform software supports the scalability to accommodate the number of network hosts with rapid growth, the adaptability on a variable environments, and the availability for a fault-tolerance.

• Journal of the Korean Institute of Navigation
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• v.5 no.2
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• pp.49-58
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• 1981

One of the main purposes of the marine gyrocompass follow-up system is to preserve the sensitive part from the wandering error due to the frictional or torsional torque around the vertical axis. This error can be diminished through the rapid follow-up action, which minimizes the relative azimuthal angular displacement between the sensitive and follow-up parts and shortens the duration of the same displacement. But an excessive rapidity of the follow-up action would result in a sustained oscillation to the system. Therefore, to design a new type of the follow-up system, the theoretical annlysis of the problems concerned should be studied systematically by introducing the control theory. This paper suggest a concrete procedure for the optimal adjustment of the gyrocompass follow-up system, utilizing the mathematic model and the stability informations formerly investiaged by the author. For theoptimal determination of the adjustable paramfter K, the performance index(P.I.), ITSE(Intergral of the Time multiplied by the Squared Error) is proposed, namely, P.I. = $\int_{0}^{\infty} t \cdot e^{2}(t)dt$ where t is time and e(t) means control error. Then, the optimal parameter minimizing the performance index is calculated by means of Parseval's theorem and numerical computation, and the validity of the obtained optimal value of the parameter Ka is examined and confirmed through the simulations and experiments. By using, the proposed method, the optimal adjustment can be performed deterministically. But, this can not be expected in the conventional frequency domain analysis. While the Mps of the original system vary to the extent of from 0.98 to 46.27, Mp of the optimal system is evaluated as 1.1 which satisfies the generally accepted frequency domain specification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.852-855
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• 2010

Based on the rapid development of the computer network technology, the ubiquitous sensor network (USN) was developed to enable us to have access to the communication environment anywhere and anytime without the need for recognizing computers or networks. Moreover, with the increasingly high interest on individual health, the USN technology is being applied to diverse sectors for healthcare and disease prevention. In this paper, a system was designed and implemented using the USN-based RF communication for doctors and nurses who care patients in the hospital to easily measure and control the physiological data on blood pressure and blood sugar. In addition, a database was designed using MS SQL database to store and manage the blood pressure and blood sugar data, which were passively or actively measured from patients. Using the results of this study, the physiological data of patients can be managed in real time and emergency situation can be instantly addressed. It is expected that the healthcare service can be improved and the paradigm of healthcare service environment can be changed.