• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.717-722
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• 2001

This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.569-578
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• 2003

This paper presents a method in which the user produces a real-time facial animation by navigating in the space of facial expressions created from a great number of captured facial expressions. The core of the method is define the distance between each facial expressions and how to distribute into suitable intuitive space using it and user interface to generate realtime facial expression animation in this space. We created the search space from about 2,400 raptured facial expression frames. And, when the user free travels through the space, facial expressions located on the path are displayed in sequence. To visually distribute about 2,400 captured racial expressions in the space, we need to calculate distance between each frames. And we use Floyd's algorithm to get all-pairs shortest path between each frames, then get the manifold distance using it. The distribution of frames in intuitive space apply a multi-dimensional scaling using manifold distance of facial expression frames, and distributed in 2D space. We distributed into intuitive space with keep distance between facial expression frames in the original form. So, The method presented at this paper has large advantage that free navigate and not limited into intuitive space to generate facial expression animation because of always existing the facial expression frames to navigate by user. Also, It is very efficient that confirm and regenerate nth realtime generation using user interface easy to use for facial expression animation user want.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.734-739
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• 2016

The globe valve is a linear motion valve that is designed primarily to stop, start, and regulate flow. The disk of a globe valve can be removed totally from the flow path or it can completely close the flow path. In this study, numerical analysis using ANSYS-CFX was initially performed to predict the flow coefficient and build a prototype model of a globe valve. The flow coefficient is the volume of water at $15.6^{\circ}C$ that will flow per minute through a valve with a pressure drop of 1 psi across the valve. In other words, it is an important factor for determining the size of the valve. From the analysis results, the fluid flux of water and flow coefficient of the valve were extracted. From the numerical results, a prototype of ultra-fine precision control valve, which can regulate the fluid flow of range 0 ~ 0.1 gal per min, was developed. The experimental results were compared with the numerical results using the flow coefficient ($C_v$) graph. From the comparative results, the flow coefficient ($C_v$) error percentage between the numerical and experimental results was very low, which is acceptable, proving that the proposed prototype model is convincing. In addition, it is possible to predict the flow coefficient using only numerical analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.655-663
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• 2017

With the development of ICT technology, the indoor utilization of robots is increasing. Research on transportation, cleaning, guidance robots, etc., that can be used now or increase the scope of future use will be advanced. To facilitate the use of mobile robots in indoor spaces, the problem of self-location recognition is an important research area to be addressed. If an unexpected collision occurs during the motion of a mobile robot, the position of the mobile robot deviates from the initially planned navigation path. In this case, the mobile robot needs a robust controller that enables the mobile robot to accurately navigate toward the goal. This research tries to address the issues related to self-location of the mobile robot. A robust position recognition system was implemented; the system estimates the position of the mobile robot using a combination of encoder information of the mobile robot and the absolute space coordinate transformation information obtained from external video sources such as a large number of CCTVs installed in the room. Furthermore, vector field histogram method of the pass traveling algorithm of the mobile robot system was applied, and the results of the research were confirmed after conducting experiments.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.1
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• pp.47-54
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• 2011

The remote control mobile robot is the robot accomplishing a task according to the orders giving by a user through departed communication system using a joystick. Basically, to supply a lot of information, as this type of robot uses visual information, the user can check the transmitted information by eyes and give orders to the robot. But the weak point of this type of robot is that it has a possibility to come into a collision with an obstacle not be seen to the user because of the communication delay occurring in a communication system and dead zone happening in visual information. To solve the problem, in this paper, we try to suggest a system applying a fuzzy control system to the robot to avoid collision with an obstacle by an immediate order of the user. The fuzzy control system has better performance than any other existing control methods in the change of noise and parameter. And it is more efficient than any other since it solves easy the complexity of the system analysis occurring because of the nonlinear feature of the mobile robot system. In this paper, we made experiments how the mobile robot controlled by the fuzzy control system avoids an obstacle, tracks the path and avoids the obstacle in the path, to prove the performance and to check the evaluation and the application possibility of the fuzzy control system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2C
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• pp.192-199
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• 2008

In ultra-wideband (UWB) systems, conventionally, the synchronization is to align time phases of a locally generated template and any of multipath components to within an allowable range. However, the synchronization with a low-power multipath component could incur significant performance degradation in receiver operation (e.g., detection) after the synchronization. On the other hand, the synchronization with a high-power multipath component can improve the performance in receiver operation after the synchronization. Generally, the first one among multipath components has the largest power. Thus, the synchronization with the first path component can make better performance than that with low-power component in receiver operation after the synchronization, Based on which, we first propose an optimal decision rule based on a maximum likelihood (ML) approach, and then, develope a simpler suboptimal decision rule for selecting the first path component. Simulation results show that the system has good demodulation performance, which uses new synchronization definition and the proposed decision rules have better performance than that of the conventional decision rule in UWB multipath channels. Between macroblocks in the previous and the current frame. On video samples with high motion and scene change cases, experimental results show that (1) the proposed algorithm adapts the encoded bitstream to limited channel capacity, while existing algorithms abruptly excess the limit bit rate; (2) the proposed algorithm improves picture quality with $0.4{\sim}0.9$dB in average.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.189-192
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• 2012

Male factor infertility or sub-fertility contributed half of all cases of infertility while the semen abnormality is the current topic of argument. Conventional analysis of semen showed poor correlation with fertility. Therefore, evaluation of current semen analysis method is necessary to improve standards of semen assessment. The goal of this study was to investigate that correlation between motion kinematic before and after capacitation and litter size in porcine. Sperm motility and kinematics were measure by computer-assisted sperm analysis (CASA). The motility of spermatozoa was positively correlated with curvilinear velocity (VCL), average path velocity (VAP), and mean amplitude of head lateral displacement (ALH) (p<0.05). Where as VCL positively correlated with VSL, VAP and ALH (p<0.01). Straight-line velocity (VSL) was positively correlated with VAP and ALH (p<0.01). VAP was significantly positively correlated with ALH (p<0.01). Also, we found significant positive correlation among variation of VSL, VAP and ALH (p<0.05). No motility and kinematic parameter are correlated with litter size. However, litter size was significantly correlated with breed (p<0.05). Our results suggested that analysis of sperm motility and kinematics using CASA is questionable for prediction of litter size. However, it has some practical importance to evaluate semen commercially.

• 한국해양학회지
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• v.30 no.1
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• pp.57-63
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• 1995

Two-layered fluid with sloping bottom and top(${\beta}$-effect) in rigid cylinder is put on the rotating table. To drive the lower-layer motion in "the Sverdrup type" flow external fluid is pumped into the lower-layer. By introducing inlet-outlet system in the upper-layer, an analogy to the Tsushima Tsugaru, Soya of the East Sea has been tested. The position of the inlet-outlet system and the difference between the strength of inlet or outlet flow are changed to see the effects of the wind stress on the upper-layer. The northern part of inflow toward the outlet may be interpreted roughly as the position of the polar front in the East Sea. Experimental observations have revealed that the inflow flows along the western boundary before it separates into the interior and flows straight toward the outlet position. However, the wind effect is imposed upon the upper-layer, the western boundary flow branches into two parts of which one flows along the boundary and the other flows into the interior under the influence of negative wind stress curl, while southward western boundary flow seems to block the flow and deflect it to the interior. The changes in the position of inlet-outlet system produce more significant changes in flow pattern in that cyclonic flow in the north controls the northern extent of the polar front by deflecting the northward interior motion toward the west(outlet). Interface displacement which depends strongly on the velocity difference between two layers seems to play crucial role in terms of the path of upper-layer flow, particularity, the inflow.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1527-1533
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• 2001

Garole is a prolific, rare, less known and small size Indian sheep breed found in low and humid Sunderban region of West Bengal. Although information on stored Garole ram liquid semen upto 24 h is available, but there is a need to further investigate the short-term and long-term preservability of Garole ram semen for extensive utilization of this valuable germplasm by artificial insemination. The aim of the present study was to apply computer-assisted sperm analysis technique for assessing the motion characteristics of Garole ram semen stored (i) in liquid state at refrigeration temperature for short-term preservation upto 48 h and (ii) in frozen state at $-196^{\circ}C$ for long-term preservation after packaging in mini straws. Short-term preservation had a significant effect on motility (p<0.01) as the motility progressively decreased from 90.1% at 0 h to 85.5% and 73.2% after 24 and 48 h of storage, respectively. Although the decline in rapid moving sperms was also significant (p<0.01) on storage but the decrease was more pronounced at 48 h as compared to 24 h of storage period. Storage of chilled semen had also a significant effect on % linearity (p<0.05), % straightness (p<0.01), sperm velocities (p<0.01), amplitude of lateral head displacement (p<0.01) and beat frequency (pO.Ol) of spermatozoa. The replication had a significant effect for all the variables except average path and straight line velocity. However, the interactions of short-term storage and replication were non-significant for most of the variables except % of medium moving sperms, sperm velocities and beat frequency. On long-term preservation of Garole ram spermatozoa under controlled conditions the mean post-thaw recovery of 70.4 and 71.4% motile spermatozoa was achieved having 48.8 and 48.9% of rapidly motile spermatozoa, respectively in both the replicates. The effect of replication on cryopreservation was significant (p<0.05) on amplitude of lateral head displacement and beat frequency, but there was no significant effect on motility, rapidly motile spermatozoa, linearity, straightness and sperm velocities of frozen-thawed spermatozoa. It can be concluded from these results that an average 70% motility can be achieved on storage of Garole ram semen in chilled liquid state upto 48 h or in liquid nitrogen after freezing under controlled conditions in straws. However, further studies are required to evaluate the fertility of short-term and long-term preserved Garole ram semen for extensive use of this prolific sheep breed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2B
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• pp.129-137
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• 2003

Multimedia streams, like MPEG continuously retrieve multimedia data because of their incessant playback. While these streams need an efficient support of kernel, the current buffer cache mechanism of Linux kernel such as Unix operating system was designed apt for small files, which is aperiodically requested as well as time uncritical. But, in case of continuous media, the CPU must enormously copy memory from kernel address space to user address space. This must lead to a large CPU overhead. This overhead both degrades system throughput and cannot guarantee QOS. In this paper, we have designed and implemented two memory copy reduction schemes in Linux kernel, direct I/O and one copy. The direct I/O skips the buffer cache layer of Linux kernel and results in dramatic reduction of CPU memory copy overhead. And, the one copy provides a fast disk-to-network data path without copying to user address space. The experimental results show considerable reduction of CPU overhead and throughput improvements.