• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.4
• /
• pp.93-99
• /
• 2016

In this paper, we investigated the mechanical and electrical reliability of silver nanowire (AgNW) films. In particular, the durability and reliability of AgNW films were studied when the AgNW film was subjected to the bending deformation under current flow. The electrical durability of AgNW was evaluated by observing changes in heat generation and current density occurring in AgNW through voltage and current tests. The AgNW film showed a constant resistance change up to a bending radius of 2 mm and 200,000 cycles in the bending fatigue tests. The over-coating layer has an effect of improving the durability of the AgNW film. In the case of AgNW with the over-coating layer, heat was uniformly dissipated on the surface of AgNW film, whereas in the case of AgNW film without the over-coating layer, heat was generated locally. In the bending test under the current flow, the current density of the AgNW film was continuously decreased up to 52.4%. During bending, the AgNW was deformed due to mechanical deformation such as tensile, bending and sliding of the AgNW, consequently contact resistance of the AgNW was increased, leading to a electrical breakdown of AgNW by Joule heating. It was found that the application of the over-coating layer can improve the electrical and mechanical reliability of the AgNW film.

• Polymer(Korea)
• /
• v.30 no.2
• /
• pp.140-145
• /
• 2006

The mort commonly available substrate material is glass in the display fibrication process. However, glass is not desirable due to its heaviness and fragility. Recently, plastics such polysulfone (PSF), polyethesulfone (PES), polycarbonate (PC), polyethylene terephthalate (PET) and cyclic olefin polymers (COP) have been investigated to replace glass as a substrate material for display fibrication. Plastic substrates are advantageous in that they are lightweight, huh impart resistance, flexibility, and ability for roll to roll manufacturing process. But many plastics have poor chemical resistance in organic solvent. The chemica resistance is also lequired because they are exposed to solvents for various chemical treatments din the manufacturing process. So, we have an interest in the chemical modification of PSF to improve chemical resistance. We introduced crosslinkable imide moieties using chloromethylation method for the modification of PSF which could be overcome above shortcomings for display substrate based on plastic film. We prepared the cross-linked polysulfone films which were represented chemical resistance in HeOH, THF, DMSO and NMP. The thermal properties were measured by TGA, DSC and TMA. As the results, we have confirmed to enhance of the thermal property. They had low coefficient of thermal expansion (CTE) which decreased to 15% and had increased $T_g\;from\;180^{\circ}C\;to\;252^{\circ}C$. Cross-linked polysulfone films with imide side-chain had good optical properties and chemical resistance so that they could be used as flexible display substrate.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.1
• /
• pp.18-31
• /
• 2021

Linoleum is a resilient, hygienic, and eco-friendly floor covering. It was developed in England by Frederick Walton in 1863. Made of cork flour, linseed oil, and burlap as its main materials, the flexible and waterproof linoleum became globally popular in the early 20th century. Unlike the vinyl coverings, the burlap-backed linoleum was used not only in commercial spaces but also in household areas like kitchens, bathrooms, and even living rooms. As a global product, linoleum was imported and used in Korean palaces like Deoksugung and Changdeokgung in the early modern period. According to the record Deoksugung Won-Ahn, linoleum was applied to the major buildings, including Hamnyeongjeon, Deokhongjeon, and Jeonggwanheon, and various other venues. The linoleum used in these places are mainly monochrome blue and brown color, which probably means that they are from England. The trade records in the early 20th century show that linoleum was imported mainly from England and America. The Ewangjik building floor plan in the Changdeokgung Palace shows that linoleum was used extensively. There are even some originals, which were laid in 1920 and left in the Changdeokgung Palace. When Daejojeon and Huijeongdang were rebuilt in 1920, the interior was outfitted with western features and linoleum was used in areas such as bathrooms, the tonsorial parlor, and one of the rooms on the west side of Huijeongdang. In situ in the Daejojeon and Huijeongdang areas in the Changdeokgung Palace are monochrome, patterned black, and stylized floral tile patterned, which are closely similar to American products made by ALC and Armstrong company. This study will help us better understand linoleum's characteristics, its uses and the material itself. It will also form the basis for the restoration of Changdeokgung Palace as well as other modern interiors with linoleum flooring in the future.

• Journal of Korea Technology Innovation Society
• /
• v.16 no.4
• /
• pp.1134-1162
• /
• 2013

The purpose of this paper is to provide an innovation strategy for a leading industrial company. We analyze the process of a shift in industrial leadership using the shipbuilding industry as a case study. This paper explains that the three core factors of decline are immobilization, lack of innovation for major products, and organizational inertia. This study presents that the leader of a market is not decided by strong competitiveness, but by quick reaction to major customers' needs, and that out-of-date strategies do not contribute to maintaining leadership. As a result of this study, it shows that the leading Korean industrial companies shall establish a new innovation-oriented and customer-oriented management system that is flexible enough to anticipate and respond to the changes in new competitive environments. These findings contribute to the formulation of new strategies for other manufacturing industries in Korea.

• Human Ecology Research
• /
• v.55 no.5
• /
• pp.507-526
• /
• 2017

To infer the true state of a regional product's attributes, consumers use the image they have of the product's region of origin; however, products may have multiple countries of origin in their design, branding, sourcing and manufacturing becuase more products are increasingly a result of multi-firm and multi-country efforts. We examined how the country-of-origin image (country image and product image) affect international consumers' perceived value (function value and symbolic value) and purchase intentions of made-in China goods by extending and deepening the flexible model. Second, to investigate the differences of COO effects according to different types of country-of-origin we divided the traditional country-of-origin into two components: country-of-manufacture (COM) and country-of-brand (COB). We then explore how the impact of China's country image on consumers' perceived value and purchase intentions varies when China is the COM or COB of the same product. Six hypotheses were proposed to test our anticipations. We recruited 800 Korean adult consumers who previously purchased made-in China products to participate in the online investigation. Data analyses were conducted with confirmatory factor analysis and structural equation modeling using SPSS and AMOS. The main results are discussed as follows. First, the effects of China's COO image on Korean consumers' perceived value and purchase intentions vary when China is the COM or COB of a product. Second, a positive effect of the function value and symbolic value on the purchase intentions was found. Literature and practical implications of findings are discussed and suggested in the conclusion.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.39 no.4
• /
• pp.137-146
• /
• 2016

In recent years, business environment is faced with multi uncertainty that have not been suffered in the past. As supply chain is getting expanded and longer, the flow of information, material and production is also being complicated. It is well known that development service industry using application software has various uncertainty in random events such as supply and demand fluctuation of developer's capcity, project effective date after winning a contract, manpower cost (or revenue), subcontract cost (or purchase), and overrun due to developer's skill-level. This study intends to social contribution through attempts to optimize enterprise's goal by supply chain management platform to balance demand and supply and stochastic programming which is basically applied in order to solve uncertainty considering economical and operational risk at solution supplier. In Particular, this study emphasizes to determine allocation of internal and external manpower of developers using S&OP (Sales & Operations Planning) as monthly resource input has constraint on resource's capability that shared in industry or task. This study is to verify how Stochastic Programming such as Markowitz's MV (Mean Variance) model or 2-Stage Recourse Model is flexible and efficient than Deterministic Programming in software enterprise field by experiment with process and data from service industry which is manufacturing software and performing projects. In addition, this study is also to analysis how profit and labor input plan according to scope of uncertainty is changed based on Pareto Optimal, then lastly it is to enumerate limitation of the study extracted drawback which can be happened in real business environment and to contribute direction in future research considering another applicable methodology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.9
• /
• pp.1679-1687
• /
• 2016

Mobile robots are effectively used in industrial fields that require flexible manufacturing systems. Mobile robots have to move with mechanical loads such as product parts along the specified paths, and are usually equipped with kinematic controllers. When the loads and nonlinear frictions are too high, satisfactory control performances can not be expected with the kinematic controllers, so some dynamic controllers have been developed. Conventional dynamic controllers require the exact weights and locations of the loads; however, the loads are frequently changed and unknown so that the control performances of the conventional controllers are limited. This paper proposes an adaptive PD control method using gradient descent learning to have sufficient dynamic control performance for unknown loads. Simulation studies have been conducted for various load conditions to verify that the adaptive PD control method have much broader convergence region than the convention method.

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.4
• /
• pp.31-39
• /
• 2010

As the linear scheduling method has been used since the Empire State Building linear schedule in 1929, it is being applied in various fields, such as construction and manufacturing. When addressing concurrent critical paths occurring in a linear construction schedule, empirical researches have stressed resource management, which should be applied for optimizing workflow, ensuring flexible work productivity and continuous resource allocation. However, work relationships have been usually overlooked in making the linear schedule from an existing network schedule. Therefore, this research analyzes the previous researches related to the linear scheduling model, and then proposes a method that can be applied for adopting the relationships of a network schedule to the linear schedule. To this end, this research considers the work relationships occurring in changing a network schedule into a linear schedule, and then confirms the activities movement phenomenon of linear schedule due to workspace change, such as physical floors change. As a result, this research can be used as a basic research in order to develop a system generating a linear schedule from a network schedule.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.957-962
• /
• 2005

Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.36-36
• /
• 2010

Currently, there are several newly developed energy resources for the future to replace petroleum resources such as hydrogen fuel cell, solar cell, wind power, and etc. Among them, solar cell has attracted a worldwide concern, because it has an enormous amount of resources. In general, a study of solar cells can be classified in to an area of bulk type and thin-film type. Inorganic solar cells based on silicon have been tremendously developed in technology and efficiency. However, since there are many lithographic steps, high processing temperature approximately $1000^{\circ}C$, and expensive raw materials, a manufacturing cost of device are nearly reaching a limit. Contrary to those disadvantages, organic solar cells can be manufactured at room temperature. Also, it has many advantages such as a low cost, easy fabrication of thin film, and possible manufacture to a large size. Because it can be made to be flexible, research and development on solar cells are actively in progress for the next generation. ever though an efficiency of the organic solar cell is low compared to that of inorganic one, a continuous study is needed. In this paper, we report optimal device structure obtained by a program simulation for design and development of highly efficient organic photovoltaic cells. we have also compared simulated results to experimental ones.