• 유통과학연구
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• 제17권7호
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• pp.87-98
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• 2019

Purpose - The goal of this research is to examine the influence of Quick Response on the supply chain performance. Furthermore, this study investigates the potential of Quick Response to be a more advanced form of supply chain collaboration program with extensive information sharing activities. Research design, data, and methodology - The mathematical model is developed to represent the two stage supply chain system with a single manufacturer and one retailer. In the numerical study with the proposed mathematical models, three supply chain systems including the traditional system, Quick Response, and the fully shared information system are compared in terms of their profits. Results - The numerical analysis shows both manufacturer and retailer obtain greater profits under Quick Response than in the traditional system. While the fully shared information outperforms Quick Response as well as the traditional system, it results in lower manufacturer's profit compared with Quick Response. Conclusions - According to the numerical examples, Quick Response is the effective supply chain collaboration program that is beneficial to every supply chain member. The fully shared information system, as a more advanced form of collaboration than Quick Response can bring more benefits to the whole supply chain system, but it is necessary to prepare the proper incentive program that enables every member to share its benefits equally.

• Structural Engineering and Mechanics
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• 제43권3호
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• pp.311-320
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• 2012

The higher-order asymptotic C(t) - $A_2(t)$ approach was employed to investigate the crack-tip stress of two collinear cracks in a power-law creeping material under the plane strain conditions. A comprehensive calculation was made of the single crack, collinear crack model with S/a = 0.4 and 0.8, by using the C(t) - $A_2(t)$ approach, HRR-type field and the finite element analysis; the latter two methods were used to check the constraint significance and the calculation accuracy of the C(t) - $A_2(t)$ approach, respectively. With increasing the creep time, the constraint $A_2$ was exponentially increased in the small-scale creep stage, while no discernible dependency of the constraint $A_2$ on the creep time was found at the extensive creep state. In addition, the creep time and the mechanical loads have no distinct influence on accuracy of the results obtained from the higher-order asymptotic C(t) - $A_2(t)$ approach. In comparison with the HRR-type field, the higher-order asymptotic C(t) - $A_2(t)$ solution matches well with the finite element results for the collinear crack model.

• Smart Structures and Systems
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• 제6권1호
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• pp.39-56
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• 2010

Structural Control relies, with a great deal, on the ability of the control algorithm to identify the current state of the system, at any given point in time. When such algorithms are designed to perform in a smart manner, several smart technologies/devices are called upon to perform tasks that involve pattern recognition and control. Smart pattern recognition is proposed to replace/enhance traditional state identification techniques, which require the extensive manipulation of intricate mathematical equations. Smart pattern recognition techniques attempt to emulate the behavior of the human brain when performing abstract pattern identification. Since these techniques are largely heuristic in nature, it is reasonable to ensure their reliability under real life situations. In this paper, a neural network pattern recognition scheme is explored. The pattern identification of three structural systems is considered. The first is a single bay three-story frame. Both the second and the third models are variations on benchmark problems, previously published for control strategy evaluation purposes. A Neural Network was developed and trained to identify the deformed shape of structural systems under earthquake excitation. The network was trained, for each individual model system, then tested under the effect of a different set of earthquake records. The proposed smart pattern identification scheme is considered an integral component of a Smart Structural System. The Reliability assessment of such component represents an important stage in the evaluation of an overall reliability measure of Smart Structural Systems. Several studies are currently underway aiming at the identification of a reliability measure for such smart pattern recognition technique.

• 한국IT서비스학회지
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• 제15권2호
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• pp.51-63
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• 2016

In this study, we conducted a comparative analysis of R&D investment efficiency and operational efficiency of IT firms using Data Envelopment Analysis (DEA). We categorized thirteen sample firms into two groups-IT manufacturing and IT service-after an extensive literature review on IT industry classification. We adopted an output-oriented two-stage DEA model suggested by Banker et al. (1984) with total asset and R&D investment as input variables. Then, we constructed investment efficiency and operational efficiency by using Return on Equity (ROE) and Return on Asset (ROA) as intervening variables and operating income and Earnings Per Share (EPS) as output variables. The outcome of the analysis is summarized as follows. First of all, IT manufacturing firms were more efficient (57% on average) than IT service firms. To be specific, IT service firms showed decreasing returns to scale (DRS) with diseconomy of scale. In contrast, IT service firms showed higher operational efficiency (81.5% on average) than IT manufacturing firms. Also, we conducted a Mann-Whitney U test to compare the output of IT service firms and IT manufacturing firms. Lastly, we found a negative correlation ($R^2$ = -.754) between R&D investment efficiency and operational efficiency which infers the trade-off between two constructs

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.498-501
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• 2005

This paper deals with the design and evaluation of the robust controller for a synchronous generator excitation system to improve the steady state and transient stability. The nonlinear characteristics of the system is treated as model uncertainties, and then the robust control techniques are introduced into the power system stability design to take into account these uncertainties at the controller design stage. The performance of the designed controller is examined by extensive non-linear time domain simulation. It is shown that the performance of the robust controller is superior to that of the conventional PI controller. This paper also proposes an improved digital exciter control system for a synchronized generator using a digitally designed controller with database. Results show that the proposed control system manifests excellent control performance compared to existing control systems. It has also been confirmed that it is easy for the proposed control system to implement digital control.

• International Journal of Quality Innovation
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• 제9권1호
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• pp.153-167
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• 2008

This paper presents the findings of a visiting scholarship research that was carried out at the Faculty of Engineering, University of Technology Sydney, Australia. Based on the extensive literature review, government databases and international statistics, it introduces an analytical framework for comparison of the national innovation systems (NIS) of China and Australia in regards to their strengths and weaknesses. This is done through individual examination and comparison of functions of typical institutions involved in innovation to reveal the structural characteristics and performances of the two systems. The interactions among these institutions are then analysed to illustrate their dynamics and efficiency. The comparison has shown clearly that China's NIS has several weaknesses and gaps due to its developing and transition stage. There are positive signs that Chinese Government has recognised the nature and scope of the problem and seems to work in the right direction. This paper aims to support this process by providing some recommendations that could help bridge the gaps between the NISs of China and Australia. Due to the fact that both, China's and Australia's NISs, have their unique characteristics but share numerous complementary features, there is a large potential for further cooperation between the two national innovation systems.

• Journal of Chest Surgery
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• 제32권6호
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• pp.595-598
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• 1999

원위부 대동맥궁류가 과도하게 커서 elephant trunk 술식을 적용하기 어려운 경우나 하행 대동맥류가 파열된 경우와 같은 합병증이 동반된, 전 흉부 대동맥을 침범하는 광범위 대동맥류에 있어서는 단계적 수술이 불가능하다. 저자들은 상행 대동맥에서부터 하행 대동맥까지의 대동맥을 동시에 치환하는 수술을 성공적으로 시행하였다. 환자는 65세 남자로서 하행 대동맥류의 파열을 동반한 전 흉부 대동맥류를 갖고 있었다. 수술은 횡행 개흉 흉골 절개술을 통하여 접근하여 초 저체온 완전 체외순환 정지 및 역행성 뇌관류하에 시행하였다. 환자는 순조롭게 회복하였으며 신경학적 합병증 없이 퇴원하였다.

• 대한두개안면성형외과학회지
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• 제21권1호
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• pp.35-40
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• 2020

Background: Extensive eyelid defects are extremely challenging to reconstruct. Although numerous procedures for reconstructing periorbital defects have been proposed, no method is universally used. However, the Tenzel flap is the most commonly used technique to reconstruct eyelid defects affecting one-third to two-thirds of the eyelid. Methods: Recognizing the usefulness of the Tenzel method, we adapted it to reconstruct larger defects around the eyes. Seven patients underwent reconstruction with a modified Tenzel flap with an extended concept after wide excision of a malignant skin lesion. The main difference from the conventional method is that the modified Tenzel flap includes the medial portion of the lower lid defect. The design of a modified Tenzel flap begins as a semicircle at the lateral canthal area, in the same way as a classical Tenzel flap, and extends medially along the subciliary line to cover the defect on the medial lower eyelid. The follow-up time ranged from 3 to 28 months. Results: All flaps survived and healed well, with minimal scarring and natural palpebral outlines. Conclusion: Compared to traditional procedures, the modified Tenzel flap has several advantages, including a one-stage operation, a less noticeable scar, and effective prevention of complications such as lower eyelid ectropion.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권1호
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• pp.83-87
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• 2005

This paper deals with the design and evaluation of the robust controller for a synchronous generator excitation system to improve the steady state and transient stability. The nonlinear characteristics of the system is treated as model uncertainties, and then the robust control techniques are introduced into the power system stability design to take into account these uncertainties at the controller design stage. The performance of the designed controller is examined by extensive non-linear time domain simulation. It is shown that the performance of the robust controller is superior to that of the conventional PI controller. This paper also proposes an improved digital exciter control system for a synchronized generator using a digitally designed controller with database. Results show that the proposed control system manifests excellent control performance compared to existing control systems. It has also been confirmed that it is easy for the proposed control system to implement digital control.

• Transactions on Electrical and Electronic Materials
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• 제11권3호
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• pp.93-105
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• 2010

Complementary metal-oxide-semiconductor (CMOS) technology scaling has been a main key for continuous progress in silicon-based semiconductor industry over the past three decades. However, as the technology scaling enters nanometer regime, CMOS devices are facing many serious problems such as increased leakage currents, difficulty on increase of on-current, large parameter variations, low reliability and yield, increase in manufacturing cost, and etc. To sustain the historical improvements, various innovations in CMOS materials and device structures have been researched and introduced. In parallel with those researches, various new nanoelectronic devices, so called "Beyond CMOS Devices," are actively being investigated and researched to supplement or possibly replace ultimately scaled conventional CMOS devices. While those nanoelectronic devices offer ultra-high density system integration, they are still in a premature stage having many critical issues such as high variations and deteriorated reliability. The practical realization of those promising technologies requires extensive researches from device to system architecture level. In this paper, the current researches and challenges on nanoelectronics are reviewed and critical tasks are summarized from device level to circuit design/CAD domain to better prepare for the forthcoming technologies.