• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.378-385
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• 2017

This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.209-221
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• 2019

Cooperating with a supplier with professional skills is necessary to achieve performance in the development of the innovative products. It is also important to improve development competence and share knowledge. This study empirically analyzed the effect of participant's Job Competence and Leadership Competence on Knowledge Sharing, and the effect of Purchaser Interdependence on Supplier Absorption Capacity. The purpose of the study is to confirm that Knowledge Sharing between Development Participant and Supplier contributes to Performance and to demonstrate the need for a cooperative relationship with the Supplier. A survey was conducted on the product development participants to confirm the relationship between the factors using a Structural Equation Model. As a result of the hypothesis test, the better the Individual Competence of the development participants, the better the Knowledge Sharing Activity, and then Knowledge Sharing and Interdependence are the main factor in the Absorption Capacity of the Supplier. The results of this study can contribute to improving the Supplier Absorption Capacity in the product development projects in which high technology is converged. In the future, we will study the effects of the project support activities of related departments for Performance.

• International Area Studies Review
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• v.12 no.3
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• pp.341-365
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• 2008

This paper investigates the properties and relative importance of Apparel Textile industry of Busan in terms of both the number of employees and the value-added, and then analyzes the relative technical efficiencies from the perspectives of space closeness such as consumption market, suppliers, living standards and clustering environments using the DEA model. The main outcomes are as follows. The Apparel Textile industry is still a key industry in Busan with relatively high intensity and high LQ (greater than one) in spite of the recent decrease between 2000 and 2005 both in the number of employees and the value-added. Those firms with consumption market showed higher efficiency in all kinds of efficiencies than the firms without the market, and further relatively higher efficiency than the firms with suppliers. In addition, the firms located in the higher living standards also showed higher values of efficiency compared with the firms in lower living standards. The policy implication from the results is that the strategic and selective investment should be made according to the relative efficiency and thus the traditional industry should be transformed to the high value added one with additional investment to utilize the scale efficiency.

• Korea Trade Review
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• v.43 no.5
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• pp.25-45
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• 2018

This paper estimates the export losses of the Korean domestic automobile industry due to US trade pressure and its economic ripple effects. Using the HS 6 digit tariff and export data from 2010 to 2017, this paper estimates the tariff elasticity of Korea's US automobile exports against a US tariff increase by applying the Poisson Pseudo maximum likelihood estimation method. After estimating Korea's export losses to the US in three trade pressure scenarios, we estimate its impact on Korean domestic production, value-added and job creation by applying the tariff impact accumulation model based on the industry input-output analysis. Empirical results show that the impact of 25% global tariff by the US on the Korean domestic economy is estimated to result in $30.8 billion in export losses for the five years from 2019 to 2023, about 300 thousand job losses, 88.0 trillion in production inducement losses, and 24.0 trillion in value-added inducement losses. The impacts of withdrawal of the automobile tariff concession are estimated at $4.27 billion export losses and 41.7 thousand job losses. A 15% tariff rate on automobile parts for 3 years is estimated to result in $1.93 billion export losses and 18.7 thousand job losses.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.96-106
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• 2009

In this paper, correlation between the headphone's acoustical characteristics and the subjective preferences is analyzed, and a possibility of predicting the subjective preferences using the acoustical characteristics is investigated, The headphone's acoustical characteristics include the total harmonic distortions, the variation of the frequency response which were measured by separate channel and the inter-aural correlation coefficients, Those characteristics were measured in a noise-free anechoic chamber, using a head and torso simulator, The subjective preferences were scored in terms of loudness, clearness, spaciousness, fullness and overall impression, In the subjective listening test, 12 subjects were participated who have plentiful listening experiences, The programs include 5 kinds of musics; korean popular song, pop song, light music, male-voice and classic, The 8 models of the headphones were employed, including 4 closed-type circumaural headphones, 2 open-type supraaural headphones and 2 intra-concha headphones, A significant test was carred on the results from the subjective test, using a two-way ANOVA test, The correlation coefficients between the acoustical parameters and the subjective preferences were computed, Experimental results showed that the variation of the magnitude of frequency response measured from a right channel revealed higher correlation with the subjective preferences. Whereas the inter-aural correlation coefficients have very low correlation coefficients.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.19-23
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• 2024

Patients with amputations of both hands need prosthetic hands that serve both cosmetic and functional purposes, and research on prosthetic hands using electromyography of remaining muscles is active, but there is still the problem of high cost. In this study, an artificial prosthetic hand was manufactured and its performance was evaluated using low-cost parts and software such as a surface electromyography sensor, machine learning software Edge Impulse, Arduino Nano 33 BLE, and 3D printing. Using signals acquired with surface electromyography sensors and subjected to digital signal processing through Edge Impulse, the flexing movement signals of each finger were transmitted to the fingers of the prosthetic hand model through training to determine the type of finger movement using machine learning. When the digital signal processing conditions were set to a notch filter of 60 Hz, a bandpass filter of 10-300 Hz, and a sampling frequency of 1,000 Hz, the accuracy of machine learning was the highest at 82.1%. The possibility of being confused between each finger flexion movement was highest for the ring finger, with a 44.7% chance of being confused with the movement of the index finger. More research is needed to successfully develop a low-cost prosthetic hand.