• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.131-142
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• 2014

Phone camera lens module is assembled with a barrel, multiple lenses, multiple spacers and a shield. The major processes of manufacturing system are injection molding, coating and assembly processes, and each process has multiple machines. In this paper, we introduce a scheduler based on simulation model which can be used for frequent rescheduling problem caused by urgent orders, breaking down of molds and failures of machines. The scheduling algorithm uses heuristic Backward-Forward method, and the objective is to minimize the number of tardy orders.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.771-778
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• 2014

In this study, we have measured the effects on production inducement, added value inducement, employment inducement and backward and forward linkage regarding the knowledge service industry in Korea. It turns out that the knowledge service industry greatly contributes to increase of added value and employment creation while highly withholds to effect on production inducement and backward and forward linkage effects. In recent, government seeks out new growth driver out of the knowledge service industry. We have found the fact that its direction should be 'production growth of the knowledge service industry' through this study.

• 전자공학회논문지 IE
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• v.48 no.1
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• pp.7-15
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• 2011

In this paper, we propose a correlation-based subspace estimation technique, which is called square-root forward/backward correlation-based projection approximation subspace tracking(SRFB-COPAST). The SRFB-COPAST utilizes the forward and backward correlation matrix as well as square-root recursive matrix update in projection approximation approach to develop the subspace tracking algorithm. With the projection approximation, the square-root recursive FB-COPAST is presented. The proposed algorithm has the better performance than the recently developed COPAST method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4C
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• pp.207-216
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• 2011

Motion compensated extrapolation (MCE) techniques show inferior performance compared to motion compensated interpolation techniques, since only past frames are used in MCE. MCE techniques are used for the reconstruction of corrupted frames, the up-conversion of frame rates and the generation of side information in the distributed video coding system. In this paper, the performance of various MCE techniques are evaluated and an efficient MCE technique using the forward and backward motion estimation is proposed. In the proposed technique, the present frame is extrapolated by averaging two frames which are generated by forward and backward motion estimation respectively. It is shown that the proposed method produces better PSNR results and less blocking phenomena than conventional methods.

• The Journal of Korean Physical Therapy
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• v.19 no.4
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• pp.25-32
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• 2007

Purpose: The purpose of this study was to evaluate the effect of computerized neurocognitive function program on cognitive function about memory and attention with stroke. Methods: 24subjects with stroke were recruited. Twelve of subjects received conventional therapy including physical therapy, occupational therapy and language therapy. Another subjects received additional computer assisted cognitive training using Computer-aided Cognitive rehabilitation training system(COMCOG, MaxMedica Inc., 2004). All patients were assessed their cognitive function of memory and attention using Computerized Neurocognitive Function Test(CNT, MaxMedica Inc., 2004) before treatment and 6 weeks after treatment. Results: Before the treatment, two groups showed no difference in cognitive function(p>0.05). After 6 weeks, two groups showed significantly difference in digit span (forward, backward), verbal learning(A5, $A1{\sim}A5$), auditory CPT(n), visual CPT(n)(p<0.05). After treatment, the experimental group showed a significant improvement of digit span(forward, backward), verbal learning(A5, $A1{\sim}A5$), visual span (forward, backward), auditory CPT(n, sec), visual CPT(n, sec), and trail-making (A, B)(p<0.05). Conclusion: Computerized neurocognitive function program would be improved cognitive function of memory and attention in patients with stoke.

• Advances in concrete construction
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• v.13 no.5
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• pp.367-376
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• 2022

Theoretical study of vibration distinctiveness of rotating cylindrical are examined for three volume fraction laws viz.: polynomial, exponential and trigonometric. These laws control functionally graded material composition in the shell radius direction. Functionally graded materials are controlled from two or more materials. In practice functionally graded material comprised of two constituent materials is used to form a cylindrical shell. For the current shell problem stainless steel and nickel are used for the shell structure. A functionally graded cylindrical shell is sanctioned into two types by interchanging order of constituent materials from inner and outer side for Type I and Type II cylindrical shell arrangement. Fabric composition of a functionally graded material in a shell thickness direction is controlled by volume fraction law. Variation of power law exponent brings change in frequency values. Influence of this physical change is investigated to evade future complications. This procedure is capable to cater any boundary condition by changing the axial wave number. But for simplicity, numerical results have been evaluated for clamped- simply supported rotating cylindrical shells. It has been observed from these results that shell frequency is bifurcated into two parts: one is related to the backward wave and other with forward wave. It is concluded that the value of backward frequency is some bit higher than that forward frequency. Influence of volume fraction laws have been examined on shell frequencies. Backward and forward frequency curves for a volume fraction law are upper than those related to two other volume fraction laws. The results generated furnish the evidence regarding applicability of present shell model and also verified by earlier published literature.

• Earthquakes and Structures
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• v.24 no.4
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• pp.237-245
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• 2023

Based on novel Galerkin's technique, the theoretical study gives a prediction to estimate the vibrations of FG rotating cylindrical shell. Terms of ring supports have been introduced by a polynomial function. Three different laws of volume fraction are utilized for the vibration of cylindrical shells. Variation frequencies with the locations of ring supports have been analyzed and these ring supports are placed round the circumferential direction. The base of this approach is an approximate estimation of eigenvalues of proper functions which are the results of solutions of vibrating equation. Each longitudinal wave number corresponds to a particular boundary condition. The results are given in tabular and graphical forms. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing length-to-radius ratio. There is a new form of frequencies is obtained for different positions of ring supports, which is bell shaped. Moreover, on increasing the rotating speed, the backward frequencies increase and forward frequencies decreases.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.57-64
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• 1997

The process design of backward and forward extrusion of axisymmetric part has been studied in this paper. The important factors of cold forging process with complex geometry are the design of initial billet shape, the possibility of forming by one-stage operation and the determination of preform shapes, etc. Based on the systematic procedure of process sequence design, the forming operation of cold forged part is analyzed by the commercial finite element program, DEFORM. The design criteria are forming load, geo- metrical filling without defect and a sound distribution of effective strain in final product. It is noted that one step of preform operation is required to obtain the final product. Numerical result is compared with experi- mental one. It is found that the analyzed result is in good agreement with actual forming result.

• Korea Trade Review
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• v.46 no.3
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• pp.45-63
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• 2021

This paper investigates the effects of China's participation in global value chains (GVC) on the productivities focusing on the manufacturing industries. In this study, several indicators of participation in global value chains were used. These include GVC participation, forward GVC participation, backward GVC participation and GVC position index. In particular, we used the data obtained from 18 manufacturing industries in China during 15 years from 2000 to 2014. The main results of the analysis are as follows. First, the higher the degree of total participation in GVC, the higher the productivity. This means that with the increase in exports and imports of intermediate goods, productivity has increased through technology spillover effects or competition effects, and so on. Second, the backward participation does not increase the productivities significantly while forward participation leads higher productivity. Third, the productivity improvement effects of GVC participation was larger in the high-tech industries than in the low-tech industries. These results show that GVC participation was helpful for the economic growth of China and the efforts for moving toward upstream production stage in GVC is necessary for the improvement of international competitiveness in Chinese manufacturing industry.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.1003-1008
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• 2013

This paper proposes a compression scheme based on the modified reversible integer transform (MRIT) and forward adaptive prediction for lossless image compression. JPEG XR is the newest image coding standard with high compression ratio and that composed of the Photo Core Transform (PCT) and backward adaptive prediction. To improve the efficiency and quality of compression, we substitutes the PCT and backward adaptive prediction for the modified reversible integer transform (MRIT) and forward adaptive prediction, respectively. Experimental results indicate that the proposed method are superior to the previous method of JPEG XR in terms of lossless compression efficiency and computational complexity.