• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.4
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• pp.461-466
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• 2013

Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using COMSOL and MATLAB interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.105-111
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• 2010

In the field of 'Human Vibration', it has been interested subjects to make equal sensation curves related to translational and rotational direction of whole-body, hand-transmitted and head-transmitted vibration, etc. When we consider the vibration of a vehicle, the main factor is vertical whole-body vibration. Until now, most of equal sensation curves used to derive frequency weighting function had been made using Western people. However, because of the inherent differences (for example, characteristic and shape of body parts, muscular and cellular tissue) between the Western people and the Oriental people, equal sensation curves based on Oriental people might be required. Also, the weight differences between the samples which consist of average-weighted and over-weighted group might cause the difference of equal sensation curves. So, in this study, 20 male Korean people were used to find equal sensation curves subject to vertical whole-body vibration on seated posture. Among 20 males, an over weighted group consisted of 10 male persons and an average weighted group was the others. Integrating and analyzing the data of two groups, some of non-parametric tests such as 'The Wilcoxon Signed Rank Test' and 'The Mann Whitney U test' were used.

• Toxicological Research
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• v.32 no.2
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• pp.103-108
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• 2016

The purpose of this study was to determine the hair growth effects of lavender oil (LO) in female C57BL/6 mice. The experimental animals were divided into a normal group (N: saline), a vehicle control group (VC: jojoba oil), a positive control group (PC: 3% minoxidil), experimental group 1 (E1: 3% LO), and experimental group 2 (E2: 5% LO). Test compound solutions were topically applied to the backs of the mice ($100{\mu}L$ per application), once per day, 5 times a week, for 4 weeks. The changes in hair follicle number, dermal thickness, and hair follicle depth were observed in skin tissues stained with hematoxylin and eosin, and the number of mast cells was measured in the dermal and hypodermal layers stained with toluidine blue. PC, E1, and E2 groups showed a significantly increased number of hair follicles, deepened hair follicle depth, and thickened dermal layer, along with a significantly decreased number of mast cells compared to the N group. These results indicated that LO has a marked hair growth-promoting effect, as observed morphologically and histologically. There was no significant difference in the weight of the thymus among the groups. However, both absolute and relative weights of the spleen were significantly higher in the PC group than in the N, VC, E1, or E2 group at week 4. Thus, LO could be practically applied as a hair growth-promoting agent.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.7-13
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• 2010

For swiftness and economic feasibility of parcel delivery, optimal location of mail exchanging centers considering not only section delivery distance but also some weights like the number of delivery vehicles are necessary. In this paper, a mechanism with section delivery distance and vehicle number for locating of mail distribution centers which connect some mail centers of major cities in Republic Korea by applying GOSST theory is proposed. This mechanism for locating mail exchange centers can make the total delivery distance of postal matters less than not only present method which assigns Daejun as mail exchange center, but also Steiner tree method which does not consider weights like number of delivery vehicles. The mechanism is good for protecting the environment as well as rapid and economic delivery. In experiment, the proposed mechanism could curtail total delivery distance by 2.52 percentages compared with Steiner tree method and by 6.66 percentages compared with present method. The mechanism may be used in electric power transmission routing, distribution line topology design, power relay station locating where various voltages and other weights should be considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.32-43
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• 2007

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. This paper proposes maximum torque control of IPMSM drive using adaptive learning fuzzy neural network and artificial neural network. This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. This paper proposes speed control of IPMSM using adaptive learning fuzzy neural network and estimation of speed using artificial neural network. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled adaptive learning fuzzy neural network and artificial neural network, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the adaptive learning fuzzy neural network and artificial neural network.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.209-213
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• 2020

In this study, the model A with the existing shape used at racing car and the model B with light weight were designed. The structural analysis with thermal deformation and stress were carried out. Model A shows that the maximum temperature is lower than model B. The cooling performance due to the shape of the disk without any other cooling conditions can be shown to be better for model A. Model A was seen to be superior in durability as the thermal stress reduced by almost twice as much as model B. The part where the greatest stress occurred appeared to be the hole jointed with the hub regardless of its shape. The analysis results at this study are seen to be useful at designing the shape of the actual vehicle brake disc. The analysis results obtained in this study can be applied at grasping the strength of the brake disk for racing car practically. By utilizing the analysis result of the brake disk for racing car, this study is seen as the convergence study that the aesthetic design and analysis are applied.

• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.541-548
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• 2004

In the maritime container terminal. LMCTS (Linear Motor-based Container Transfer System) is horizontal transfer system for the yard automation, which In., been proposed to take the place of AGV (Automated Guided Vehicle). The system is based on PMLSM (Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car (mover). Because of large variant of mover's weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's trouble etc. LMCTS is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the softcomputing method of a multi-step prediction control for LMCTS using DR- FNN (Dynamically-constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi step prediction Consequently, the system has an ability to adapt for external disturbance, detent force, force ripple, and sudden changes by loading and unloading the container.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1871-1880
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• 2011

In this paper, a controller for two wheeled inverted pendulum robot, i.e., Segway type robot that is a convenient and easily handled vehicle is designed to have more stable balancing and faster velocity control compared to the conventional method. First, a widely used PID control structure is applied to the two wheeled inverted pendulum robot and proper PID control gains for some specified weights of users are obtained to get accurate balancing and velocity control by use of experimental trial-and-error method. Next, neural network is employed to generate appropriate PID control gains for arbitrarily selected weight. Here the PID gains based on the trial-and-error method are used as training data. Simulation study has been carried out to find that the performance of the designed controller using the neural network is more excellent than the conventional PID controller in terms of faster balancing and velocity control.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.3
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• pp.107-112
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• 2018

In this paper, optical flow based keypoint detection and tracking technique is proposed for the collaboration between flying drone with vision system and ground robots. There are many challenging problems in target detection research using moving vision system, so we combined the improved FAST algorithm and Lucas-Kanade method for adopting the better techniques in each feature detection and optical flow motion tracking, which results in 40% higher in processing speed than previous works. Also, proposed image binarization method which is appropriate for the given marker helped to improve the marker detection accuracy. We also studied how to optimize the embedded system which is operating complex computations for intelligent functions in a very limited resources while maintaining the drone's present weight and moving speed. In a future works, we are aiming to develop collaborating smarter robots by using the techniques of learning and recognizing targets even in a complex background.

• The Journal of Korean Medicine
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• v.33 no.2
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• pp.1-10
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• 2012

Objectives: This study was aimed to investigate the effect of Bojungikgitang-gagambang (BJIG) on longitudinal bone growth in rats. Methods: The BJIG treated group (300 mg/kg) and the control group (vehicle) were administered orally twice daily for 4 days. To investigate the effects of BJIG we measured body weight gain. The bone growth effect was analyzed by measuring between fluorescent lines marked with tetracycline, which plays the role of fluorescent dye on the surface of the tibia. Tetracycline was intraperitoneally injected. The height of growth plates in the epiphyseal plate was measured. The expression of bone morphogenetic protein-2 (BMP-2) and insuline-like growth factor-1 (IGF-1) was investigated by immunohistochemistry. Results: BJIG caused a significant acceleration of longitudinal bone growth of $349.7{\pm}15.9{\mu}m/day$ compared to control ($319.8{\pm}21.4{\mu}m/day$). The height of overall growth plate was not significantly more compared to the control, but the size of cells in the proliferative zone and hypertrophic zone were. In the immunohistochemistry, BMP-2 and IGF-1 were expressed markedly in the proliferative or hypertrophic zone, respectively. Conclusions: BJIG stimulated the chondrocyte hypertrophy and chondrogenesis in the growth plate and directly increased the longitudinal tibia length of rats.