• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.69.6-69
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• 2001

The SSPA makes the power level of EIRP up to 16W, and compensates for temperature to the SSPA´s maximum stability. The up and the down converters are dually conversed like as individual synthesizers for selecting of independent transmit-receive transponder. The function of the up-converter is to convert the 70MHz IF signal modulated in the indoor unit modem into a 14.0 ∼ 14.5 GHz Ku-band up-link signal to be sent to the antenna. The down-converter converts the 12.25 ∼ 12.75 GHz Ku-band down-link signal or a trouble malfunction of SSPA may be a fatal factor to operation of the whole satellite communication network. Therefore, this study developed the remote monitoring and control program to monitor the SSPA´s status before the problem occurs for stable operation of the system. This software ...

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.138-144
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• 2014

Purpose: This study examined the water sorption of commonly used dual-cure resin cements and compared the change in the micro-hardness among the cements. Materials and Methods: Five types of dual-cure resin cements (Maxcem, Duo-link, Panavia F, Variolink II, Rely X Unicem) were selected. Fifty specimens were classified into five groups containing ten specimens in each group. The water sorption of the five specimens in each group was evaluated after being immersed in distilled water (DDW) for seven days. The following results were obtained by comparing the specimens immersed in DDW with those not immersed in DDW. Results: 1. The water sorption of Maxcem showed the highest score, followed by Panavia F. These two cements were followed by Duo-link and Rely X Unicem. The water sorption of Variolink II showed the lowest score among the cements used in this study. 2. Among the specimens not immersed in DDW, the micro-hardness of Rely X Unicem showed the highest score followed by Panavia F and Variolink II. These cements were followed in order by Duo-link and Maxcem. 3. Among the specimens immersed in DDW, the microhardness of Rely X Unicem showed the highest score followed by Maxcem, Panavia F and Variolink II. Duo-link shoed the lowest score among the cements used in this study. 4. Maxcem, Duo-link, Panavia F and Rely X Unicem showed significant differences in micro-hardness due to water resorption but Variolink II was unaffected by immersion in water. Conclusion: Using the resin cement which has lower water sorption and higher micro-hardness is recommended.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.115-124
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• 2010

VDF(volume-delay function) is one of the most important factor to improve the reliability of traffic demand estimation because it is for estimation of link travel time based on the traffic volume variation. Because VDF of link except for freeway is applied as the parameter of BPR(bureau of public road) of U.S., it causes to deteriorate the accuracy of traffic demand estimation. The purpose of this paper is to establish new parameter of VDF based on the real-surveyed traffic data in order to improve the problem of the existing VDF. We suggest the reclassification of road hierarchy, the approach of traffic survey, the estimating method of VDF parameter, and the improvements of new VDF application. The new VDF allows us to estimate more realistic traffic situation in parts of demand, travel time and path between origin-destination.

• The Journal of Korean Medical History
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• v.28 no.1
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• pp.111-119
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• 2015

Objectives : The Dongui Bogam in My Hand', which is an output of computerizing Donguibogam (Principles and Practice of Eastern Medicine), is an interim outcome of the research project led by the Korea Institute of Oriental Medicine. This study examined the process in which Donguibogam, a record in Chinese and a classic of Oriental medicine, expanded into a modern content. Methods : This study will classify the modernization of Donguibogam into three 'contents' that form Donguibogam, 'container' that will hold the contents, and 'community' that is the consumer of Donguibogam. Towards the end, this study will sketch out the status of computerizing Chinese records in Korea, and point out the reality faced by computerization of ancient documents on Oriental medicine as well as the direction for the future. Results : 'The Dongui Bogam in My Hand' has been downloaded more than 10,000 times for 4 months since it releases in August 2014, and is used for at least 6,000 times on average every month. This achievement can be due to the two following reasons. First, the application contains high-quality contents such as the original text of Donguibogam as well as Korean and English translations. Second, it satisfied the needs of Donguibogam users with (1) the Browse function that well displays the table of contents, (2) the Search function that separates the title from the main text, and (3) the Personalization function designed to link and share relevant knowledge. Conclusions : Computerization of Chinese records was triggered by the request of the academia, but it was accelerated after being selected as a public laboring project to overcome the IMF crisis. However, computerization of ancient documents is not a simple task but a field of study to modernize classical knowledge. The success or failure of computerization of Chinese records is determined by whether high-quality modern 'contents' are secured, whether the 'container' design adequately implements the search, browse and link functions, and how well it fulfills the needs of the consumer 'community'.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.65-74
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• 2016

Ship ad-hoc network (SANET) extends the coverage of the maritime communication among ships with the reduced cost. To fulfill the growing demands of real-time services, the SANET requires an efficient clock time synchronization algorithm which has not been carefully investigated under the ad-hoc maritime environment. This is mainly because the conventional algorithms only suggest to decrease the beacon collision probability that diminishes the clock drift among the units. However, the SANET is a very large-scale network in terms of geographic scope, e.g., with 100 km coverage. The key factor to affect the synchronization performance is the signal propagation delay, which has not being carefully considered in the existing algorithms. Therefore, it requires a robust multi-hop synchronization algorithm to support the communication among hundreds of the ships under the maritime environment. The proposed algorithm has to face and overcome several challenges, i.e., physical clock, e.g., coordinated universal time (UTC)/global positioning system (GPS) unavailable due to the atrocious weather, network link stability, and large propagation delay in the SANET. In this paper, we propose a logical clock synchronization algorithm with multi-hop function for the SANET, namely multi-hop clock synchronization for SANET (MCSS). It works in an ad-hoc manner in case of no UTC/GPS being available, and the multi-hop function makes sure the link stability of the network. For the proposed MCSS, the synchronization time reference nodes (STRNs) are efficiently selected by considering the propagation delay, and the beacon collision can be decreased by the combination of adaptive timing synchronization procedure (ATSP) with the proposed STRN selection procedure. Based on the simulation results, we finalize the multi-hop frame structure of the SANET by considering the clock synchronization, where the physical layer parameters are contrived to meet the requirements of target applications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2595-2602
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• 2009

In this paper, we proposed and implemented web robot using active script engine with internet explore to process javascript function link, which is not processing in conventional web searching robot. This web searching robot is developed to measure collecting amount of web searching robot with processing of javascript function link. We analysed the architecture of web searching robot with google and naybot to develope web searching robot, implemented element of configuration applicable to searching robot and designed with distributed processing type. In addition to, we estimated the proposed web robot employing javascript processing model and analysed the comparison of collecting amount of web site board using javascript. We obtained the result of 1,000 web page collecting compared to conventional method in case of 1,000 web site board.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1014-1021
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• 2008

This paper proposes an intelligent sliding mode control method for robotic systems with the unknown bound of model uncertainties. In our control structure, the unknown bound of model uncertainties is used as the gain of the sliding controller. Then, we employ the function approximation technique to estimate the unknown nonlinear function including the width of boundary layer and the uncertainty bound of robotic systems. The adaptation laws for all parameters of the self-recurrent wavelet neural network and those for the reconstruction error compensator are derived from the Lyapunov stability theorem, which are used for an on-line control of robotic systems with model uncertainties and external disturbances. Accordingly, the proposed method can not only overcome the chattering phenomenon in the control effort but also have the robustness regardless of model uncertainties and external disturbances. Finally, simulation results for the five-link biped robot are included to illustrate the effectiveness of the proposed method.

• Journal of Korean Society of Transportation
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• v.14 no.3
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• pp.27-44
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• 1996

The purpose of the thesis is providing a new formulation for the transit assignment problem. The existing models dealing with the transit assignment problem don't consider the congestion effects due to the insufficient capacity of transit vehicles. Besides, these models don't provide solutions satisfying the Wardrop's user equilibrium conditions. The congestion effects are considered to be concentrated at the transit stops. For the transit lines, the waiting times at the transit stops are dependent on the passenger flows. The new model suggests the route section cost function analogous to the link performance function of the auto assignment to reflect the congestion effects in congested transit network. With the asymmetric cost function, the variational inequality programming is used to obtain the solutions satisfying Wardrop's condition. The diagonalization algorithm is introduced to solve this model. Finally, the results are compared with those of EMME/2.

• Journal of Mechanical Science and Technology
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• v.14 no.11
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• pp.1225-1231
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• 2000

This paper proposes a V-shaped Lyapunov function approach for the model-based control of flexible-joint robots, in which a new model-based nonlinear control scheme is designed based on a V-shaped Lyapunov function. The proposed control guarantees global asymptotic stability for link trajectory control while keeping all internal signals bounded. Since joint flexibility is used as a control parameter, the proposed control is not restricted by the degree of joint flexibility and be applied to flexibility-joint, partly-flexibility, or rigid-joint robots without modification. the effectiveness of the proposed control has been by computer simulation.

• Kyungpook Mathematical Journal
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• v.55 no.4
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• pp.753-771
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• 2015

A complete invariant defined for (closed connected orientable) 3-manifolds is an invariant defined for the 3-manifolds such that any two 3-manifolds with the same invariant are homeomorphic. Further, if the 3-manifold itself can be reconstructed from the data of the complete invariant, then it is called a characteristic invariant defined for the 3-manifolds. In a previous work, a characteristic lattice point invariant defined for the 3-manifolds was constructed by using an embedding of the prime links into the set of lattice points. In this paper, a characteristic rational invariant defined for the 3-manifolds called the characteristic genus defined for the 3-manifolds is constructed by using an embedding of a set of lattice points called the PDelta set into the set of rational numbers. The characteristic genus defined for the 3-manifolds is also compared with the Heegaard genus, the bridge genus and the braid genus defined for the 3-manifolds. By using this characteristic rational invariant defined for the 3-manifolds, a smooth real function with the definition interval (-1, 1) called the characteristic genus function is constructed as a characteristic invariant defined for the 3-manifolds.