• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.311-326
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• 2005

The paper deals with the problem of selective harvesting in a prey-predator model with predator self limitation. Criteria for local stability and global stability for both the exploited and unexploited system are derived. The effort has been considered as a dynamic variable and taxation as a control instrument to protect the fish populations from over exploitation. Finally, the optimal taxation policy is discussed with the help of control theory.

• Journal of Information Technology Applications and Management
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• v.10 no.2
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• pp.61-71
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• 2003

Ad-hoc networks are characterized by multi-hop wireless links, frequently changing network topology and the need for efficient dynamic routing protocols. In an Ad-hoc network, each host assumes the role of a router and relays packets toward final destinations Because a packet is broadcast to all neighboring nodes, the optimality criteria of wireless network routing is different from that of wired network routing. tn this paper 1 point out the more important cost factor than the number of links in the Ad-hoc network. A class routing protocols called on-demand protocols has recently found attention because of their low routing overhead since it performs a blind flooding to look for a path. In this paper, 1 propose the method which reduces overhead by using the information of neighboring nodes and doing a selective flooding. Simulation results demonstrate better reduction of routing overheads with this scheme.

• Korean Journal of Human Ecology
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• v.1 no.1
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• pp.126-142
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• 1998

The purpose of this study was to investigate the relationship between perceived risk and purchasing behavior of clothing gift among adult women. Data were collected from 258 adult women reside in Kwangiu who have ever been to purchase clothing gift during recent six months using a qusetionaire. Frequency Analysis, Factor Analysis, Correlation Analysis, T-test were carried out in the collected data. The findings were as follows; 1. The types of risks that respondents perceived when they purchased clothing gift were identified as practical-economic risk, the social-psychological risk, the fashionable risk and the time-refunding risk. 2. The higher the self-satisfaction motivation was, the higher the social-psychological risk and the higher the practical motivation was, the higher the practical-economic risk (P<.001). 3. The degree of the perceived risks of the Low Planning Group was higher than that of the High Planning Group (P＜.001). 4. When the respondents perceived social-psychological risk high, they considered brand, fashionability, and store type as more important selective criteria and when the practical-economic risk perceived high, practicality, store service were conidered more important (P＜.05). 5. When respondents perceived social-psychological and fashionable risk high, they used both personal information and non-personal information high (P<.01). (Korean J Human Ecology 1(1) : 126∼142, 1998)

• Physical Therapy Rehabilitation Science
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• v.10 no.3
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• pp.304-310
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• 2021

Objective: This study aimed to investigate effective cueing methods for selective muscle activation of gluteus medius muscles. Design: Cross sectional study design. Methods: Using the inclusion criteria for this study, 20 healthy adults, both males and females were selected for the measurement of muscle activation of gluteus maximus, gluteus medius, and tensor fascia latae muscles while performing clamshell exercise, basic movements in leg raise in side-lying, and 3 different cueing methods. Electromyogram was used to measure muscle activation, and both muscle activation and muscle ratio were compared during the basic movements and different cueing methods. Results: Gluteus medius activation was highest using "try not to make your body rotate" (cueing method 2) in both clamshell exercise and leg raise side-lying (F=5.533, p<0.05, F=7.771, p<0.05), and muscle ratio was highest in clamshell exercise using cueing method 2 (p<0.05) and "don't move your tensor fascia late" (cueing method 1) in leg raise side-lying (p<0.05). This study showed that cueing method 1 in leg raise side-lying and cueing method 2 in clamshell exercise were the most effective cueing methods for selective muscle activation of gluteus medius muscle. Conclusions: The results of this study may be used as basic information for future studies on muscle activation and muscle ratio for different cueing methods and different muscles in various exercises.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.363-366
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• 2001

It is very difficult to maintain the performance of estimation models for the new breed of projects since the computing environment changes so rapidly in terms of programming languages, development tools, and methodologies. So, we propose to use the relevant cases for a neural network model, whose cost is the decreased number of cases. To balance the relevance and data availability, the qualitative input factors are used as criteria of data classification. With the data sets that have the same value for certain qualitative input factors, we can eliminate the factors from the model making reduced neural network models. So we need to seek the optimally reduced neural network model among them. To find the optimally case-selective neural network, we propose the search techniques and sensitivity analysis between data points and search space.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.61-63
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• 2015

In the low pressure selective catalytic reduction (LP SCR) system, the uniformity of both ammonia concentration and exhaust gas flow at the SCR catalyst layer are important design factor for the efficient SCR-deNOx performance. According to the shape of the guide vane and static mixer, numerical simulations were conducted to analyze flow patterns and finally to find out the appropriate alternative for uniform flow at the front of catalyst in the real scale LP SCR reactor. The variations of gas velocity and ammonia concentration were quantitatively evaluated. Based on the present results, the shape was devised to satisfy the design criteria.

• Journal of Power Electronics
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• v.15 no.4
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• pp.964-973
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• 2015

This paper presents a simple approach for the selective harmonic elimination (SHE) of multilevel inverter based on the transistor-clamped H-bridge (TCHB) family. The SHE modulation is derived from the sinusoidal voltage-angle equal criteria corresponding to the optimized switching angles. The switching angles are computed offline by solving transcendental non-linear equations characterizing the harmonic contents using the Newton-Raphson method to produce an optimum stepped output. Simulation and experimental tests are conducted for verification of the analytical solutions. An Altera DE2 field-programmable gate array (FPGA) board is used as the digital controller device in order to verify the proposed SHE modulation in real-time applications. An analysis of the voltage total harmonic distortion (THD) has been obtained for multiple output voltage cases. In terms of the THD, the results showed that the higher the number of output levels, the lower the THD due to an increase number of harmonic orders being eliminated.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1071-1088
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• 2017

For dual-hop multiple-input multiple-output (MIMO) decode-and-forward relaying systems, we propose a selective relaying scheme that uses orthogonal space-time block code (OSTBC) and transmit antenna selection with maximal-ratio combining (TAS/MRC) or vice versa at the first and second hops, respectively. The aim is to achieve an asymptotically identical performance to the dual-hop relaying system with only TAS/MRC, while requiring lower feedback overhead. In particular, we give the selection criteria based on the antenna configurations and the average channel powers for the first and second hops, assuming Rayleigh fading channels. Also, the numerical results are shown for the outage performance comparison between the dual-hop DF relaying systems with the proposed scheme, only TAS/MRC, and only OSTBC.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.63-73
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• 2021

Purpose : Selective functional movement assessment(SFMA) is a movement-based assessment tool designed for clinicians to diagnose and treat pain and functional physical problems. This concept is used for assistance in occupations related to movement, including clinical medical personnel, such as physical therapists, physical education instructors, and athlete coaches. Although this concept is widely used by clinicians, research and scientific proofs are relatively insufficient. This study aimed to review the literature on the understanding, reliability and effectiveness of SFMA, and to consider its role in the future of rehabilitation. Methods : In this review, a total of nine articles were selected according to the eligibility criteria of three major thesis topics. The main topics covered in the literature are reliability and effectiveness of clinical use of SFMA. To gather research articles, we searched official term 'Selective Functional Movement Assessment'. Among the searched 60 studies, nine were mentioned in this study that contained overlapping information and matched our desired topic. We reviewed four reliability analyses, four case reports, and one experimental study. Results : Reliability has an intermediate degree between high raters and within raters. The validity of the SFMA system is influenced by a combination of experience and logic; hence, further improvement is needed. Therefore, if the intervention was effective based on the diagnosis result, then biomechanical evidence is necessary to further support the claim. Conclusion : In future research, to use SFMA as a diagnostic tool with high accuracy, it is necessary to improve the reliability of the main problem through breakout, support for guidelines and validity and efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.25-31
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• 2018

Selective Laser Melting is one of the representative 3D printing techniques for handling metal materials. The main factors influencing the characteristics of structures fabricated by the SLM method include the build-up angle of structures, laser power, laser scan speed, and scan spacing. In this study, the tensile properties of AlSi10Mg alloys were investigated by considering the build-up angle of tensile test specimens, laser scanning speed and scan spacing as variables. The yield stress, tensile strength, and elongation were considered as tensile properties. From the test results, it was confirmed that the yield stress values were lowered in the order of 0, 45, and 90 based on the manufacturing direction of the tensile specimen. The maximum yield stress value was obtained at 1870 mm / min based on the laser scan speed. The yield stress size decreased with decreasing scan speed. Based on the laser scan spacing, as the value increases, the yield stress increases, but the variation is smaller than the other test criteria. The tendency of the tensile strength and elongation variation depending on the test conditions was difficult to understand.