• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.446-452
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• 2016

Recently, heat resistant super alloys (which are wear-resistant, corrosion-resistant, and heat-resistant), have been used as the basic structural material in offshore and petrochemical plants. On the other hand, making valves from very expensive, high heat-resistant alloys increases the production cost and decreases its market competitiveness. To solve these problems, the technique of overlaying only those that flow on the fluid has been used as an effective method. Nevertheless, because the former technique of overlaying the ball is performed manually, it takes too much time and perfect welding is difficult to perform. To solve this problem, this study developed a robot automation system that can make uniformly overlay welding of the ball for ball-valves. The system consists of a 6-axis welding robot with a welding torch and additional 2 axes for the rotation of positioner, the controller, and a robot path OLP (Off-Line Programming). The CAD drawing data was entered in the Off-line program to obtain the robot teaching point and drive source. Overlay welding paths were implemented using Matlab. Through an automated overlaying system that implemented the OLP, the productivity rose 2.58 times, as the amount of time required for work decreased from 88 hours to 41 hours.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.187-193
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• 2006

Background : Normal cell proliferation and viability is strongly depends on the availability of metabolic energy and the maintenance of the appropriate adenylate-nucleotide pools. Hypothetically, changes in adenylate kinase (AK) expression could therefore be associated with adaptation to altered growth characteristics or inversely altered growth characteristics of proliferating cells could drive the changes in the metabolic profile. This study investigated whether the expression of either AK1 or a Mycobacterium tuberculosis adenylate kinase mutant which has the same catalytic activity of AK1 could affect the growth rate of slow-growing BCG. Method : Recombinant BCGs, which were cloned the human muscle-type adenylate kinase synthetic gene (AK1) and adenylate kinase mutation gene (AKmtDM) of Mycobacterium tuberculosis into the Mycobacterium/E.coli expression vectors, were constructed. Recombinant BCGs and wild-type BCG were cultured in 7H9 media and the optical density at 600nm was measured at intervals of 2-3 days. Result : There wasn't the growth rate change induced by AK1 or AKmtDM expression in recombinant BCGs. Conclusion : The expression of AK1 or Mycobacterium tuberculosis adenylate kinase mutant in BCG does not affect the growth rate of BCG.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1585-1592
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• 2018

Due to un-balancing weight allocation on the wheelchair the existing wheelchair system are faced with the risk of flipping or falling when a wheelchair goes up to a hill. In to order to be safer during riding the wheelchair, in this paper, we proposed a real-time new solution using the integrated Gyro Sensor and Tilt Sensor for controlling the balance. Because the typical property of wheelchair is for the special user who meets the difficulty in moving on foot the maintain the balance of wheel-chair systems have become important and helpful. In our method, we calculate the seat angle using information from Tilt Sensor. However, due to the law of inertia when a wheelchair is moving there is a deviation in the output value of Tilt Sensor. Therefore, we have to optimize the value of the angle by utilizing the acceleration that is the output of the Gyro Sensor. We took the advantages by using the combination of Gyro and Tilt sensors. Moreover, we also solved the consumption issue of the whole system. Through various experimentations with usage of ZigBee sensor module, the power consumption for the balancing system is reduced significantly.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.48-60
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• 2004

This study is aimed at examining the relationship between health behaviors practices and physical and psychological stresses of radiological technologists who are working at general hospitals across the country. For this purpose, a survey was conducted to 890 subjects by means of questionnaires from the middle of July to the end of August 2003, which resulted in the following outcomes: 1. From the technical and statistical analysis into the physical and psychological states, the item 'I feel miserable and dejected' scored the highest points of (3.91), implying that most subjects got heavily stressed, while the item 'Life is worth living' recorded (2.59), representing that only a few of them got less stressed. 2. With regard to an analysis of variance depending on their regular exercise, a significant difference appeared in 7 items(Pl, P2, P5, P6, P12, P17, and Pl8)(P<0.05). 3. Out of analysis into such variance as smoking, significant results were found in the items 'I become uncomfortable or disturbed at night' and 'I can solve my own problems'(P<0.05), while no significant difference was confirmed in other items regardless smoking. 4. From the T-test conducted to the independent sample depending on the drive under the influence, a significant difference was shown only in the item 'I feel very exhausted, even eating is a labo'( P<0.05). 5. The T-test with the independent sample of drinking coffee, the item 'I am satisfied with the method and the procedure of things I do' turned out to be significant( P<0.05) while no particular difference was confirmed in other items. In conclusion, it was revealed from the study that the physical and psychological states and health-related practices of radiological technologists seemed to be more affected by regular exercise than by smoking or drinking wine or coffee, a result confirming that the health-related acts are closely associated with the socio-psychological stresses. It is, therefore, strongly suggested that the practice of health-related acts to properly control stress will contribute to promoting health and pre venting disease of radiological technologists.

• Journal of Drive and Control
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• v.12 no.4
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• pp.60-70
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• 2015

A front-end loader (FEL) mounted on an agricultural tractor is one of the most commonly used implements for farm work. However, when the tractor carries material using the bucket attached to the FEL on a sloping ground, the materials can spill or roll back over the operator due to the tilted body, thereby requiring the bucket surface to remain level at a constant value regardless of varying slopes. In this study, an active system for controlling the angle of the FEL bucket on a tractor based on the real-time measurement of ground slopes was developed to enable the bucket to constantly remain level. A FEL simulator operated based on an electro hydraulic proportional valve (EHPV) was constructed in the laboratory to develop a proportional-integral-derivative (PID) controller forming a virtual electronic control unit (ECU) on the computer, which could automatically adjust the bucket angles depending on varying input angles while sending SAE-J1939 associated messages via CAN BUS to the EHPV. The different parameter values for the PID controller due to the gravity effect of the bucket were determined using a manual PID tuning method while assuming that the tractor travels on either an ascending slope or a descending slope. The developed PID control-based self-leveling system showed a mean of steady-state errors of within $1^{\circ}$ and a mean of delayed times of ~ 0.8s when the step input of $+20^{\circ}$ was given, implying that the developed system and control algorithm would be effective in maintaining the bucket angle at a certain value. Future studies include the improvement of the control algorithm to reduce such a time delay as well as the application of the developed algorithm to the FEL mounted on a tractor tested at a testing ground.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.221-221
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• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.

• The KIPS Transactions:PartD
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• v.17D no.5
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• pp.337-346
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• 2010

Timing diagram is popularly utilized for the reason of its advantages; it is convenient for timing diagram to describe behavior of system and it is simple for described behaviors to recognize it. Various techniques are needed to test systems described in timing diagram. One of them is a technique to derive the system into a certain condition under which a test case is effective. This paper proposes a technique to automatically generate the test input sequence to reach the condition for systems described in timing diagram. It requires a proper input set which satisfy transition condition restricted by input waveform and timing constraints to generate a test input sequence automatically. To solve the problem, this paper chooses an approach utilizing the linear programming, and solving procedure is as follows: 1) Get a Timing diagram model as an input, and transforms the timing diagram model into a linear programming problem. 2) Solve the linear programming problem using a linear programming tool. 3) Generate test input sequences of a timing diagram model from the solution of linear programming problem. This paper addresses the formal method to drive the linear programming model from a given timing diagram, shows the feasibility of our approach by prove it, and demonstrates the usability of our paper by showing that our implemented tool solves an example of a timing diagram model.

• Quality Improvement in Health Care
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• v.10 no.1
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• pp.58-76
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• 2003

Background : Aim of this study is focused on the analysis of the needed abilities of medical representatives resulting in building up the market and increasing sales. It is to propose methods to increase this ability ensuring continuous growth in market share and profit. Methods : A survey was conducted between January 6 and May 31, 2003. Using SPSS(Version 10.0), the collected data was analyzed by Hotelling T2, factor analysis. Some hypotheses were selected to include the conclusion. Some questionnaires for physicians working in hospitals or clinics and the medical representatives working in a pharmaceutical company were created and asked to them to either prove or reject those hypotheses. The results were analyzed to find the primary factors that effect the interactions between physician and the medical representatives. These factors were also studied along with the theoretical research based on published references. Results : The results were as follows. The main reasons for the physician to meet with a medical representatives were collection of product informations needed for patient treatment and collection of informations on current medical issue and as well as personal interests. The main parameters by which physicians evaluate the medical representatives are human relationship including sincerity and manners and supply of accurate and unbiased information on products. Overall, the medical representatives' perception on the importance of medical knowledge and ability to deliver it are lower than that expected by physicians. Conclusion : Medical and pharmaceutical companies' environment are changed rapidly. And those changes forced medical representatives to set new roles and competency. In order to drive away from the past 'rule of thumb' and 'adaptation to circumstance', optimal method and systemic development to train and support the medical representatives should be quipped. They will help medical representatives to be specialists in medical knowledge and to understand the exact need of health care professions. Product competitiveness will be increased and eventually successful business can be achieved through it.

• Journal of Korea Technology Innovation Society
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• v.10 no.4
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• pp.629-653
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• 2007

Korean government drives various programs to improve the performance of university-industry cooperation since 1998 such as BK 21(Brain Korea), NURI(New University for Regional Innovation), Connect Korea Program, and so on. We analyse the relationships between performance of university-industry cooperations and university competency factors(research competency and management competency) through multi-regression model, and propose policy implication. We used the basic data related to the performance of university-industry cooperation and university competency factors from Korean 61 universities. We set up some hypotheses and try to verify them with the method of multi-variable regression analysis including dependent variable(licensing fee, the number of technology transfers, the number of spin-offs) and independent variables(research competency, management competency). We, through this analysis, find both the research competency variables and management competency variables are significant to the performance of university-industry cooperation. Firstly, for licensing fee and the number of technology transfers, research competency variables such as the number of SCIE papers, the number of patent registration were significant, but management competency variables such as the scale of technology leasing organization, the number of specialist were not significant. Secondly, for the number of spin-offs management variables are significant, but research competency varialbles are not. These results imply that both the research competency and management competency of universities are the critical factors for the effective commercialization of university technology not only in United States but also in Korea. In the conclusion, we propose government drive university-industry cooperation policy to enhance the quality of research papers and patent as well as management capabilities of technology leasing organization.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.6
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• pp.754-761
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• 2008

As the automobile industry and technologies are developed, driver's tend to more concern about service matters than mechanical matters. For this reason, interests about recognition of human knowledge and emotion to make safe and convenient driving environment for driver are increasing more and more. recognition of human knowledge and emotion are emotion engineering technology which has been studied since the late 1980s to provide people with human-friendly services. Emotion engineering technology analyzes people's emotion through their faces, voices and gestures, so if we use this technology for automobile, we can supply drivels with various kinds of service for each driver's situation and help them drive safely. Furthermore, we can prevent accidents which are caused by careless driving or dozing off while driving by recognizing driver's gestures. the purpose of this paper is to develop a system which can recognize states of driver's emotion and attention for safe driving. First of all, we detect a signals of driver's emotion by using bio-motion signals, sleepiness and attention, and then we build several types of databases. by analyzing this databases, we find some special features about drivers' emotion, sleepiness and attention, and fuse the results through Multi-Modal method so that it is possible to develop the system.