• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.57-64
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• 2021

The domestic semiconductor industry can produce various products that will satisfy customer needs by diversifying assembly parts and increasing compatibility between them. It is necessary to improve the production line as a method to reduce the work-in-process inventory (WIP) in the assembly line, the idle time of the worker, and the idle time of the process. The improvement of the production line is to balance the capabilities of each process as a whole, and to determine the timing of product input or the order of the work process so that the time required between each process is balanced. The purpose of this study is to find the optimal WIP and buffer size through SA (Simulated Annealing) that minimizes lead time while matching the number of two parts in a parallel assembly line with bottleneck process. The WIP level and buffer size obtained by the SA algorithm were applied to the CONWIP and DBR systems, which are the existing production systems, and the simulation was performed by applying them to the new hybrid production system. Here, the Hybrid method is a combination of CONWIP and DBR methods, and it is a production system created by setting new rules. As a result of the Simulation, the result values were derived based on three criteria: lead time, production volume, and work-in-process inventory. Finally, the effect of the hybrid production method was verified through comparative analysis of the result values.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.2
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• pp.186-193
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• 2002

A new integrated torque and speed control algorithm has been proposed for the load balancing of rollers in continuous strip processing line(CSPL). Using the proposed method, the output torque and speed can be controlled to follow the reference in spite of nonideal effects such as the speed reference error and/or the controller gain difference between rolls. This new algorithm can be easily implemented in a motor drive system of each roll as it does not require the torque feedback of the others. Through the simulation and experiments for a simple CSPL consists of four driven rolls, the load balancing performance of the proposed scheme is presented and compared with that of conventional method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.313-317
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• 2009

The orifice in the propellent feeding pipe line of a Liquid Rocket Engine(LRE) is used to balance the pressure of the pipe line. When a LRE starts up, pressure at the upstream of the orifice rapidly increases. In this case, pressure waves occuring by resistance of the orifice may induce low frequency instability in the pipe line. For this reason the study of dynamic characteristics of orifices is needed to prevent the instability. A pump is used to build up the pressure, and the pressure is measured upstream and downstream of the orifice when the orifice diameter is changed. With the increase of orifice diameter, water hammer decreases, but the effect of resistance downstream is increases.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.3
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• pp.353-360
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• 1999

An investigation made of the variations of angle of bias on the top of the sleeve cap curve line and calculated easing contraction ratio by capheights(A ; a,h$\times$5,/6) B: A, H/4 +4cm C:A.H/3 D: A.H/ 4+3cm E:AH/4+2cm, F: A,H/4+1cm, G: A,H/4, H:A,H/6, I:A,H/8) and the efects of easing contraction on the cap curve lines of sleeve A, D, G by easing stitch density with the gathering foot: sewing condition-lockstitch industrial machine stitch density(N1.0 ; 38stitches/3cm N1.5: 26stitches/3cm, N2.0 ; 19stitches/3cm, N2.5 ; 14stitches/ 3cm) The results obtained were as follows; 1) The variations of the angle of bias on the top of the sleeve cap curve line by cap heights can be done according to the angle balance (front; $\alpha$-$\beta$ back ; $\alpha$'- $\beta$') between the angle (front ;$\alpha$, $\beta$, back ; $\alpha$'- $\beta$') of bias of the two base-lines. 2) The higher cap height the more higher the calculated easing contraction ratio. 3) The lower the stitch density the higher easing contraction ratio. 4) The effects of easing contraction was that sleeve G was more than sleeve A, D.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1275-1282
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• 2009

The tunnel excavations are used for construction of common utility tunnel, electric tunnel, communication line tunnel, water supply and public sewerage pile line in urban area. The trench cut methods were mainly used in the past, but now, tunneling method is more being used. The tunnel excavation method like as NATM, Messer-Shield, Semi-Shield Methods are being applied to small section tunnel in Korea. The actual construction results of seme-shield method are increasing due to simplified construction process and reduced noise and vibration. And also this method is being used frequently in waterway tunnel and construction of prevention flooding recently. The seme-shield method design guideline is absence except for electric line tunnel construction in Korea, because of the semi-shield method was developed in Europe and Japan. In the prescriptive design, engineer's subjects are tending to intervene, because of absence of standard and specification for details. Therefore, Design and Construction Problems of Semi-Shield Method were described and construction trouble was introduced for exam. These problem and construction troubles have to be examined thoroughly in advance.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.178-187
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• 2007

One important issue in power systems is dynamic instability due to loosing balance relation between electrical generation and a varying load demand that justifies the necessity of stabilization. Moreover, Power System Stabilizer (PSS) must have capability of producing appropriate stabilizing signals over a wide range of operating conditions and disturbances. To overcome these drawbacks, this paper proposes a new method for robust design of PSS by using an auto-tuning fuzzy control in combination with Real-Coded Genetic Algorithm (RCGA). This method includes two fuzzy controllers; internal fuzzy controller and supervisor fuzzy controller. The supervisor controller tunes the internal one by on-line applying of nonlinear scaling factors to inputs and outputs. The RCGA-based method is used for off-line training of this supervisor controller. The proposed PSS is tested in three operational conditions; nominal load, heavy load, and in the case of fault occurrence in transmission line. The simulation results are provided to compare the proposed PSS with conventional fuzzy PSS and conventional PSS. By evaluating the simulation results, it is shown that the performance and robustness of proposed PSS in different operating conditions is more acceptable

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.2
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• pp.272-291
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• 2022

The purpose of this study is to analyze the external characteristics of the clothes formed from the culture and worldview of Goryeo women and to identify the aesthetic characteristics. This paper posits the following: First, that the practice of Buddhism contributed to gender equality between Goryeo women and men; second, that Goryeo had a worldview of unified as in with the East and Korea differentiating from the dichotomous thinking of the West; and third, that the aesthetic characteristics of Goryeo women's clothing included (a) color contrast and an emphasis on patterns based on Pure Land Buddhism and Esoteric Buddhism; (b) The beauty of unitary convergence is the beauty of freedom as an expression of various cultural exchanges and the free and open ways of thinking of Goryeo women; (c) an expression of rhythmical beauty, with the shape of line led to straight to curve line and the change of line through human body's movements; and (d) a perfect balance of proportion and symmetry based on Pure Land Buddhism.

• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.47-54
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• 2019

The purpose of this study was to investigate the effect of visual conditions on the static balance of stable and unstable surfaces. Thirty healthy adults participated in this study (13 men, 17 women). Visual conditions were set as vertical, horizontal, and diagonal. It was performed on the pad to measure the balance on the unstable support surface. Using the balance measuring instrument, the General Stability Index, Weight Distribution Index, and Weight Distribution was measured. Paired t-tests were used for ground-based comparisons and one-way ANOVAs were used for comparisons within the same ground. The general stability index showed a significant difference according to the horizontal and vertical line directions on the stable support surface(p<.05). According to the comparison between the grounds, the weight distribution index on the unstable support surface showed a significant difference(p<.05). Weight distribution showed significant differences between the left and right eyes on the support surface with the stable and the unstable horizontal visual condition(p<.05). In static balance training, vertical and diagonal visual direction conditions are predicted to be helpful for training.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.215-224
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• 2022

The purpose of this study is to analyze how it affects functional movement and dynamic balance applying Czech get up exercise based on the principle of motor development of child for office worker women in 30s and 40s. Through random allocation, an Czech get up exercise group(n=15) and a control group(n=14) were formed to apply exercise for 12 weeks, 3 times a week, and 60 minutes a day, and the control group maintained daily life at the same period. As a result of the study, showed that Deep squat(p<.05), Hurdle step(p<.01), In-line lunge(p<.05), Trunk stability push-up(p<.001), Rotary stability (p<.01), Total score(p<.001), were significantly in the Czech get up Group, and Dynamic Balance of Lower Extremity(p<.001), Right Dynamic Balance of Lower Extremity(p<.001) were also significantly in the Czech get up Group. In conclusion, it is thought that Czech get up exercise based on the principle of motor development of child will have a positive effect on the functional movement and dynamic balance in office women, thereby increasing work efficiency as well as healthy life.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.357-366
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• 2012

Construction equipment has applied to depreciation over the years, however, the price index for construction equipment is not properly reflected in existing quantity per unit and the local tax law. Thus, this study shows the analysis of the corporate tax law, the local tax law and business accounting standards, characteristics of the domestic depreciation system and depreciation methods, and the capital recovery factor of construction equipment applying the theory for economic efficiency. It also presents cases of depreciation on the basis of quantity per unit and tax law using straight-line depreciation method and declining balance method. It is proposed that the relations of the application system of permissible period for construction equipment and the existing system be explained and the application system of permissible period for construction equipment be imposed. Furthermore, it proposes the development of depreciation tables of construction equipment monthly expenses based on the domestic price index and applications. In addition of that, it proposes the analysis of pros and cons of the methods suggested and application limits of the study and subsequent improvement plans. This study should reflect more rational and objective reality in quantity per unit and tax law.