• Journal of Magnetics
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• 제19권4호
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• pp.315-322
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• 2014

In this work, Artificial Neural Network (ANN) was used to model the dynamic behavior of ferromagnetic hysteresis derived from performing the mean-field analysis on the Ising model. The effect of field parameters and system structure (via coordination number) on dynamic critical points was elucidated. The Ising magnetization equation was drawn from mean-field picture where the steady hysteresis loops were extracted, and series of the dynamic critical points for constructing dynamic phase-diagram were depicted. From the dynamic critical points, the field parameters and the coordination number were treated as inputs whereas the dynamic critical temperature was considered as the output of the ANN. The input-output datasets were divided into training, validating and testing datasets. The number of neurons in hidden layer was varied in structuring ANN network with highest accuracy. The network was then used to predict dynamic critical points of the untrained input. The predicted and the targeted outputs were found to match well over an extensive range even for systems with different structures and field parameters. This therefore confirms the ANN capabilities and indicates the ANN ability in modeling the ferromagnetic dynamic hysteresis behavior for establishing the dynamic-phase-diagram.

• 과학기술학연구
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• 제3권2호
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• pp.61-82
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• 2003

급격한 기술변화와 새로운 산업의 출현과정에서 기업은 현재의 능력을 바탕으로 새로운 능력을 구축하여 환경변화에 적응한다. 기업 능력의 진화과정에 대한 연구는 이러한 과정에서 기업이 가지는 본질과 특성이 산업간 경계를 넘어 어떻게 발생하는지 설명할 수 있으며, 이를 통해 기업이 잠재적인 미래 산업에서 가지는 차별성과 경쟁우위의 근원이 무엇인지 알 수 있다. 본 논문에서는 기존 문헌에 대한 고찰을 통해 새로운 산업에 참여하는 기업의 차별성이 어떤 요소에 의해 발생하고, 각 요소의 영향은 시간의 흐름에 따라 어떻게 변화하는지를 살펴보고자 한다.

• 전자공학회논문지B
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• 제31B권10호
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• pp.44-52
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• 1994

In this paper, we assume that the dynamics of DC motor and nonlinear load are unknown. We propose an inverse dynamic model of DC motor and nonlinear load using the artificial neural network and construck speed control system based on the proposed dynamic model. We also propose another dynamic model with speed prediction scheme using the artificial neural network that removes the undesirable time delay effect caused by the computation time during the real-time control. We suggest a dynamic model which has arbitrary number of speed arguments and is especially effective when the motor and load has large moment of inertia. Next, we suggest a controller that combine the neurocontrol and PID control with constant gain. We show that the proposed neurocontrol systems have capabilities of noise rejection and generalization to have good velocity tracking through computer simulations and experiments.

• International Journal of Aeronautical and Space Sciences
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• 제13권1호
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• pp.99-105
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• 2012

Track-before-detect techniques based on dynamic programming have provided solutions for detecting targets from a sequence of images. In its application to airborne threat detection, dynamic programming solutions should take into account the distinguishable properties of objects in a collision course. This paper describes the development of a new track scoring function that accumulates scores for airborne targets in Bayesian framework. Numerical results show that the proposed scoring function has slightly better detection capabilities.

• 국제물리치료학회지
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• 제9권4호
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• pp.1651-1656
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• 2018

The purpose of this study was to assess the changes in balance and proprioception of adults with limited ankle joint dorsiflexion, after the application of talocrural joint mobilization. The subjects of this study included 23 college students in their twenties with limited ankle joint dorsiflexion. The students were randomly assigned to the ankle joint mobilization group (AJMG, n=12) and the control group (CG, n=11). After 2 weeks of intervention using grade III talocrural joint mobilization in the anterior-posterior movement, the balance and proprioception of the subjects were assessed. Static/dynamic balance capabilities and ankle proprioception were analyzed using paired t-test and independent t-test. The dynamic balance and proprioception of AJMG were significantly improved after intervention (p<.05), In the comparison between the groups after the intervention, the dynamic balance and proprioceptive sense of AJMG were significantly improved compared to the control group (p<.05). This study suggests that AJMG can help improve the dynamic balance and proprioception.

• 한국기계가공학회지
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• 제20권2호
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• pp.72-79
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• 2021

The present paper aims to set forth a two-dimensional theory for the dynamics of plates that is valid over a large range of excitation. To construct a dynamic plate theory within the long-wavelength approximation, two dimensional-reduction procedures must be used for analyzing the low- and high-frequency behaviors under the dynamic variational-asymptotic method. Moreover, a separate and logically independent step for the short-wavelength regime is introduced into the present approach to avoid violation of the positive definiteness of the derived energy functional and to facilitate qualitative description of the three-dimensional dispersion curve in the short-wavelength regime. Two examples are presented to demonstrate the capabilities and accuracy of all of the formulas derived herein by using various dispersion curves through comparison with the three-dimensional finite element method.

• 반도체디스플레이기술학회지
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• 제20권2호
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• pp.137-140
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• 2021

High dynamic range (HDR) technology has been drawing attention in the field of imaging and consumer entertainment. As tools for capturing and creating HDR contents, encoding, and transmission evolve to support HDR formats, various display capabilities are being developed and increased. Hence, there is need for remapping native HDR imagery for display on lower quality legacy standard dynamic range (SDR) displays. This operation is referred to as tone mapping. In this paper, we present a sectional tone mapping method by Lenzen, and expand upon a tone mapping approach to improve temporal stability while maintaining picture quality. Compared to the existing block-based sectional tone mapping, our method uses the edge awareness-based tone mapping. We estimate the performance of the objective metric on temporal flickering. The experimental result shows that the algorithm maintains a smoother relationship between the output luminance values, and this reveals success in reducing halos and improving temporal stability with adopted edge aware filtering.

• Journal of Communications and Networks
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• 제18권4호
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• pp.540-550
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• 2016

Since energy efficiency has become a significant concern for network infrastructure, next-generation network devices are expected to have embedded advanced power management capabilities. However, how to effectively exploit the green capabilities is still a big challenge, especially given the high heterogeneity of devices and their internal architectures. In this paper, we introduce a hierarchical power management architecture (HPMA) which represents physical components whose power can be monitored and controlled at various levels of a device as entities. We use energy aware state (EAS) as the power management setting mode of each device entity. The power policy controller is capable of getting information on how many EASes of the entity are manageable inside a device, and setting a certain EAS configuration for the entity. We propose the optimal local control policy which aims to minimize the router power consumption while meeting the performance constraints. A first-order Markov chain is used to model the statistical features of the network traffic load. The dynamic EAS configuration problem is formulated as a Markov decision process and solved using a dynamic programming algorithm. In addition, we demonstrate a reference implementation of the HPMA and EAS concept in a NetFPGA frequency scaled router which has the ability of toggling among five operating frequency options and/or turning off unused Ethernet ports.

• 무역학회지
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• 제47권6호
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• pp.97-117
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• 2022

Amid the growing importance and growth potential of venture firms worldwide, this study aimed to figure out the effect of new product development capabilities (NPDC) on the internationalization of Korean venture firms and the moderating impact of founders' human capital. NPDC is a core competency that can cope with the rapidly changing market environment and is required when entering multinational markets. Therefore, we subdivided founders' human capital into professional experience, startup experience, education level, and marketing capacity and examined each moderating effect on a venture firm's internationalization. As a result of empirical analysis of 1,362 Korean venture firms using the Tobit model, this study found that venture firms with excellent NPDC tend to achieve a higher level of internationalization. In addition, among the founder's human capitals, professional experience, education level, and marketing competency moderated the positive relationship between NPDC and internationalization. In contrast, the founder's startup experience was insignificant. The results of this empirical analysis explain the factors that trigger the internationalization performance of venture firms from the perspective of dynamic capabilities and suggest that the founder's human capital played an essential role in the internationalization.

• 벤처창업연구
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• 제15권4호
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• pp.175-192
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• 2020

본 연구는 중소기업 종사자를 중심으로 양면적혁신활동을 매개변수로 하여 기업의 동적역량이 기업성과에 미치는 영향에 관하여 분석하였다. 동적역량의 하위변수를 기회탐색역량, 자원획득역량 및 자원재구성역량으로 구분하였다. 수도권에 거주하는 중소기업 종사자들로부터 수집한 설문지 282부를 실증분석에 사용하였다. SPSS v22.0과 Process macro v3.4를 사용하여 병렬다중매개모형을 기반으로 분석하였다. 분석결과 첫째, 기회탐색역량과 자원획득역량이 양면적혁신활동에 정(+)의 유의한 영향을 미치는 것으로 나타났고 자원재구성역량이 양면적혁신활동에 미치는 영향은 유의하지 않은 것으로 나타났다. 둘째, 양면적혁신활동이 기업성과에 유의한 영향을 미치는 것으로 나타났다. 셋째, 기회탐색역량과 자원획득역량이 기업성과에 정(+)의 유의한 영향을 미치는 것으로 나타났고 자원재구성역량과 기업성과 간의 인과관계는 없는 것으로 나타났다. 넷째, 양면적혁신활동은 기회탐색역량과 기업성과 간을 매개하는 것으로 나타났다. 다섯째, 양면적혁신활동은 자원획득역량과 기업성과 간을 매개하는 것으로 나타났다. 여섯째, 양면적혁신활동은 자원재구성역량과 기업성과 간을 매개하지 않는 것으로 나타났다. 후속 연구로는 본 연구에서 사용된 매개변수 외에 제 3의 매개변수 발굴과 이를 통한 직렬매개모형 분석과 조절변수가 동시에 포함된 조건부과정 모형을 도입하여 조절된 매개분석을 위한 연구가 필요할 것으로 여겨진다.