• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.4
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• pp.754-763
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• 2001

The purpose of this study was to examine: 1) the differences in the automation level by company characteristics(i.e., product category, product type, firm size); 2) the effects of company context(i.e., environmental uncertainty, task uncertainty) on the automation level; and 3) the effect of the automation level on manufacturing performance(i.e., quality, flexibility, time, cost). Data were collected from a mail survey. Four hundred eighty two questionaries were mailed to apparel manufacturers nationwide, and 60 responses were analyzed. The results revealed that: 1) mens and womens wear manufacturers and large manufacturers(i.e., the number of employees, sales volume) showed higher automation level; 2) environmental complexity positively affected the automation level; and 3) the automation level had a positive effect only on quality performance.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.201-206
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• 2005

In order to realistically represent the complex turbulence-chemistry interaction at the partially premixed turbulent lifted flames encountered in the gas turbine combustors, the combined conserved-scalar/level-set flamelet approach has been adopted. The parallel unstructured-grid finite-volume method has been developed to maintain the geometric flexibility and computational efficiency for the solution of the physically and geometrically complex flows. Special emphasis is given to the swirl effects on the combustion characteristics of the lean-premixed gas turbine combustor. Numerical results suggest that the present approach is capable of realistically simulating the combustion characteristics for the lean-premixed gas turbine engines and the lifted turbulent jet flame with a vitiated coflow.

• East Asian Economic Review
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• v.24 no.1
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• pp.31-59
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• 2020

China's increasing trade volume and continuous integration with global financial markets have strengthened the influences of the renminbi on the exchange rates of different currencies. Previous studies find closer co-movements between the renminbi and other currencies. This paper is novel to investigate the underlying determinants of the co-movement further, using panel data of over thirty-four countries. Our results show that stronger bilateral trade and financial linkages with China have a positive association with the currency co-movement. Moreover, countries with greater flexibility in exchange rate regimes show stronger co-movements. These findings imply that growing co-movements are the consequence of autonomous decisions at the market rather than that of management by governments or central banks.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.91-100
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• 2007

Many manufacturing devices must execute motions as quickly as possible to achieve profitable high-volume production. Most of them have devices having flexibility and a time delay of one sampling is added to the plants when they are controlled by fast discrete controllers, which brings about non-minimum phase zeros. This paper develops a control strategy that combines feedforward and feedback control with command shaping for such devices. First, the feedback controller is designed to increase damping and eliminate steady-state error. Next, the feedforward controller is designed to speed up the transient response. Finally, an appropriate reference profile is generated using command-shaping techniques to ensure fast point-to-point motions with minimum residual vibration. The particular focus of the paper is to understand the interactions between these individual control components. The resulting control strategy is demonstrated on a model of a high-speed semiconductor manufacturing machine.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.887-902
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• 1994

Within the framework of anisotropic thermoelasticity, the problem of an interlaminar crack in a laminated fiber-reinforced composite subjected to a uniform heat flow is investigated. Under a state of generalized plane deformation, dissimilar anisotropic half-spaces with different fiber orientations are considered to be bound together by a matrix interlayer containing the crack. The interlayer models the matrix-rich interlaminar region of the fibrous composite laminate. Based on the flexibility/stiffness matrix approach, formulation of the current crack problem results in having to solve two sets of singular integral equations for temperature and thermal stress analyses. Numerical results are obtained, illustrating the parametric effects of laminate stacking sequence, relative crack size, crack location, crack surface partial insulation, and fiber volume fraction on the values of mixed mode thermal stress intensity factors.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.220-226
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• 2020

Graphene has been widely considered a promising candidate for high-quality chemical sensors, owing to its outstanding characteristics, such as sensitive gas adsorption at room temperature, high conductivity, high flexibility, and high transparency. However, the main drawback of a graphene-based gas sensor is the necessity for external heaters due to its slow response, incomplete recovery, and low selectivity at room temperature. Conventional heating devices have limitations such as large volume, thermal safety issues, and high power consumption. Moreover, metal-based heating systems cannot be applied to transparent and flexible devices. Thus, to solve this problem, a method of supplying the thermal energy necessary for gas sensing via the self-heating of graphene by utilizing its high carrier mobility has been studied. Herein, we provide a brief review of recent studies on self-activated graphene-based gas sensors. This review also describes various strategies for the self-activation of graphene sensors and the enhancement of their sensing properties.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.174-178
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• 1991

ATM, the core technology of BISDN, provides a high degree of flexibility with regard to varying bandwidth requirements for different services. In ATM networks, since users may exceed the traffic volume negotiated at the call setup, traffic from users may need to be monitored and enforced to comply with traffic parameters. The leakybucket mechanism is one of the typical traffic enforcement methods based on the use of transmission tokens for each cell. In this mechanism the major system parameters are size of input buffer, size of token pool, and token generation ratio. In order to represent ATM cell arrivals we assume a Poisson process. In this paper, a state transition analysis technique is used to study the cell loss rates for various values of system parameters.

• International Commerce and Information Review
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• v.8 no.1
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• pp.69-86
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• 2006

The trade volume between South and North Korea has reached 1 billion dollars in year 2005. This means the economic motives may prevail over the political concerns between two regimes from now on. At the same time, the direct telecommunication lines installed to promote the IT collaboration. Based on these monumental issues, the research focuses on the workable mechanism of the South-North Korean e-Market Place(e-MP) collaboration project. The research analyzes on the capabilities as well as willingness of the South and North Korea for the e-MP, and concludes with four stepwise approach to promote the South and North Korean e-MP. The first step initiates the web marketing integration, and then the second step provides the legal environments. The third step promotes the on-/off- trade-automation via infrastructure collaboration, and the final step expands and deepens the flexibility as well as openness of the e-MP.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.104-108
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• 2018

Lithium-ion batteries have been used in energy storage systems (ESS), electric vehicles (EVs), etc. due to their high safety, fast charging and long lifecycle. This paper aims to improve the convenience of users by changing the wired battery stack used in the battery pack, wirelessly using RFID, reducing the internal volume of the battery pack, reducing the size of the battery pack. In this paper, we propose a battery management system which can provide the flexibility of battery pack expansion and maintenance by using lithium ion battery, battery management system (BMS) and wireless communication for light weight of 1Kw small battery pack. Also, by flexibly arranging the cell layout inside the battery pack and designing to reduce the size of the outer shape of the battery pack.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1264-1267
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• 2012

We rationally designed and synthesized metallopolymers with organic 1,4-benzenedicarboxylic acid (BDC) linkers with different lengths of oxyethylene side chains in order to examine the influence of side chains on the coordination characteristics. While in a previous report the BDC linkers with alkyl side chains were found to form three-dimensional (3D) isoreticular metal-organic framework (IRMOF) structures or one-dimensional (1D) coordination polymeric structures with short $-O(CH_2)_6CH_3$ or long $-O(CH_2)_9CH_3$ side chains, respectively, new BDC linkers with oxyethylene side chains of the same lengths, $-(OCH_2CH_2)_2CH_3$ and $-(OCH_2CH_2)_3CH_3$, form only 3D IRMOF structures. This result is attributed to the higher flexibility and smaller volume of oxyethylene side chains compared to alkyl side chains.