• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.60-70
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• 1998

A harmonic drive is compact torque transmission device with no backlash which is widely applied in industrial field to transmit torque precisely. However, one of the disadvantages of harmonic drives is the existence of mechanical flexibility caused by its structural properties, which imposes great limitation on designing precise controller This paper proposes a nonlinear controller for synchronous operation of DC servo-motors with harmonic drive, using Integrator Backstepping method. Furthermore, an alternative algorithm for serial type synchronous operation of multiple DC servo-motors is proposed. Simulation results by SIMULINK for proposed controller shows considerably small error and rapid approach to reference input, which can be adapted to industrial applications.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.738-739
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• 2006

This paper will describe a powder and processing method that facilitates single press-single sintered densities approaching $7.5g/cm^3$. At this sintered density, mechanical properties of the powder metal (P/M) component are significantly improved over current P/M technologies and begin to approach the performance of wrought steels. High performance gears have the added requirement of rolling contact fatigue durability that is dependent upon localized density and thermal processing. Combining high density processing of engineered P/M materials with selective surface densification enables powder metal components to achieve rolling contact fatigue durability and mechanical property performance that satisfy the performance requirements of many high strength automotive transmission gears. Data will be presented that document P/M part performance in comparison to conventional wrought steel grades.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.133-136
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• 2002

VoiceXML is designed for creating audio dialogs that feature synthesized speech, degitized audio, recognition of spoken and DTMF key input, recording of spoken input, telephony, and mixed-initiative conversations. Uses the VoiceXML and there is a Place objective which does information home appliance machinery and tools control. When it uses tile VoiceXML, il will be able to provide a bias characteristic to the user The XML base the gearing with different civil official system is possible. With studying YoiceXML and OSGi, this paper has designed and implemented the control architecture of Information home appliances.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.134-135
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• 2006

Ancorsteel 4300, a high performance Cr-Si-Ni-Mo steel, was unveiled two years ago as the first in a series of powder metallurgy alloys that will simulate wrought steel compositions. Advantages of this alloy include good compressibility, high hardenability, and excellent dimensional stability. More important, however, is that this alloy has the ability to be effectively sintered at $1120^{\circ}C$ and maintain oxygen contents below 500 ppm. This unique blend of performance and processing capabilities provides static and dynamic properties that exceed those of conventional powder metallurgy alloys and approach wrought gearing materials. A second Cr-Si-Ni-Mo alloy has now been developed that offers complimentary performance levels at a lower Mo content. This manuscript reviews properties of the two chromium steels with comparisons to traditional sinter-hardened and heat-treated powder metallurgy alloys.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.4
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• pp.85-93
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• 2009

Bird strike is big issue in aviation. Because a bird strike causes not only an aircraft damage but also a fatality, aviation societies are gearing up to prevent a bird strike. However, the accidents is not going down yet. Annal average of bird strikes in Korea is 1.15 accidents per ten thousand of flight, which is lower than the other country, for example 1.84 accidents in France and 2.38 accidents in Switzerland, 1.15 accidents. In the U.S.A, there are 89,727 accidents for the 19 year(1990-2008). Also flight delay is total 637,692 hours. The cost is total 350,258 billion dollar and 18,435 billion dollar per year. In related with those data's, this research is about the current and legal status of the bird strike. Also it will be useful to establish aviation safety policy and manage the bird strike.

• Journal of Information Technology Services
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• v.1 no.1
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• pp.119-139
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• 2002

It is noteworthy that IMT -2000 communication network based on All-HP/AIN(Advanced Intelligent Network) should accomodate current and future wire/wireless AIN service easily through integration and gearing AIN construction elements. In this paper. Intelligent Farmer model(I-Farmer Model) and methodology are suggested in order to solve the several problems including standardization on implementation of Q3 interface in Telecommunication Management Network(TMN) agents which is caused by heterogeneous platform environment and future maintenance. Also this paper proposes ITI algorithm transforming the system which is designed by I-Farmer model to Interface Specification Model(ISM) applying the I-Farmer model. In addition to ITI algorithm. we suggest NTS(Node to SIB) algorithm converting entity node and ILB/OLB component in agent system designed by the I-Farmer model to SIB of AIN GFP(Global Functional Plane) and to ASIB for application program.

• Macromolecular Research
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• v.16 no.6
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• pp.481-488
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• 2008

Apoptosis is a natural cell suicide mechanism to maintain homeostasis. However, many of the diseases encountered today are caused by aberrant apoptosis where excessive apoptosis leads to neurodegenerative disorders, ischemic heart disease, autoimmune disorders, infectious diseases, etc. A variety of antiapoptotic agents have been reported to interfere with the apoptosis pathway. These agents can be potential drug candidates for the treatment or prevention of diseases caused by dysregulated apoptosis. Obviously, world-wide pharmaceutical and biotechnology companies are gearing up to develop antiapoptotic drugs with some products being commercially available. Polymeric drug delivery systems are essential to their success. Recent R&D efforts have focused on the chemical or bioconjugation of antiapoptotic proteins with the protein transduction domain (PTD) for higher cellular uptake with antibodies for specific targeting as well as with polymers to enhance the protein stability and prolonged effect with success observed both in vivo and in vitro. All these different fusion antiapoptotic proteins provide promising results for the treatment of dysregulated apoptosis diseases.

• 월간산업보건
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• s.5
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• pp.4-15
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• 1988

In order to proffer the fundamental data for the better working environment and the effective establishment of hearing conservation program on workers exposed to industrial noise, author assessed noise levels on the 42 noisy processes among 84 manufactures of 9 industries and measured noise gearing loss by the type of industries on 3,104 workers at these noisy processes from March, 1986 to Februry, 1987. The results were summarized as follows: 1. The averge of A-weight sound level of 23 processes(54.8%) and the avergae of sound level at each octave band of 14 processes(33.3%) exceeded the permissible exposure limits in 8 hours per day. 2. The noise level was the highest in process of cocking of ship building(109.1dBA), and followed by plating of steel rolling(104.3dBA), rivet of manufacture of motor vehicles(102.5dBA), shot of ship building(98.5dBA), aciding(95.7BA) and steel tubing(95.0dBA) of steel rolling, weaving of textiles(95.0dBA). 3. The permissible exposure time for the average of sound level at each octave band was only 30 minutes in the process of cocking of ship building, plating of steel rolling and rivet of manufacture of motor vehicles. 4. As a result of audiometric examination in 3,104 workers, the rate of hearing loss over 50dB at 4,000Hz was 7.3%(227 workers) and the rate of hearing loss over 41dB at 60average method was 2.9%(89 workers). 5. The prevalence of occupational hearing loss in ship building and manufacture of motor vehicle was 5.2% and it was the highest among prevalence of these 9 industries. 6. As a result of this suvery, the noise control and gearing conservation program were required especially in the industry of ship building and manufacture of motor vehicle.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.767-771
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• 2006

Recently, the User Created Contents is rising up. Gearing with an era of the Web 2.0, The pre existed Potal and private web pages are having extensive changes, and the heart of the changes is just the contents what the users produce and spread by themselves. Therefore, there is an observation about the system of contents spread on Web media until nowadays, and the features, in this article. This paper will be intend to expect that the commonness between the examples of the current User Contents, technologies for User contents, and the possibilities for development.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1705-1709
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• 2005

The hydraulic LSD which uses the principle of gear pump is packed with viscous oil in tight container. When a slip occurs on one wheel, the hydraulic LSD generates torque caused by high oil pressure in the container. In this study, two dimensional(2-D) side pinion gear model was developed for hydraulic LSD. Using that model the flow analysis was conducted to preestimate pressure distributions of the side pinion gear according to the variations in the design factors such as oil viscosity, gear gap and rpm. Then, applying the obtained pressure distributions on the side pinion gear, finite element analysis was conducted to evaluate the torque characteristics. From the analysis results, the torque characteristics according to the design factor variations were evaluated.