• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.209-224
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• 2008

Various types of high-purity limestone, which occurred in the Pungchon Formation, are examined to understand applied-mineralogical factors controlling their calcination characters with respect to the ore characters. To do this work, systematic characterization and determination were carried out for the limestone ores and their calcination products in a fixed heating condition, and the results were correlated and discussed. During the calcination experiment, a phase transition from calcite to quicklime begins to occur selectively in the physical weak zones such as grain boundary, cleavage and twin planes. All the fabrics of original limestones are preserved in the resultant quicklime. In addition, crystallinity of the quicklime was advanced, as the aging time of calcination was increased. Major controlling factors on the calcination effects of the high-purity limestone are elucidated to be the degree of development of cleavage and twin, together with crystallinity and textures in the limestone ore. Especially, lower crystallinity and dense interlocking fabrics obviously play advantageous role in all the calcination characters. But the development of cleavage and twin affects negatively on the calcination characters on account of favoring decrepitaion of quicklime in the lime manufacturing. Thus, the high-purity limestones characteristic of marble fabrics and relatively lower crystallinity are comparatively advantageous for the uses of lime manufacture.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.145-154
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• 2004

The growing demand for customer-responsive, made-to-order manufacturing is stimulating the need for improved dynamic decision-making processes in commercial fleet operations. Moreover, the rapid growth of electronic commerce through the internet is also requiring advanced and precise real-time operation of vehicle fleets. Accompanying these demand side developments/pressures, the growing availability of technologies such as AVL(Automatic Vehicle Location) systems and continuous two-way communication devices is driving developments on the supply side. These technologies enable the dispatcher to identify the current location of trucks and to communicate with drivers in real time affording the carrier fleet dispatcher the opportunity to dynamically respond to changes in demand, driver and vehicle availability, as well as traffic network conditions. This research investigates key aspects of real time dynamic routing and scheduling problems in fleet operation particularly in a truckload pickup-and-delivery problem under various settings, in which information of stochastic demands is revealed on a continuous basis, i.e., as the scheduled routes are executed. The most promising solution strategies for dealing with this real-time problem are analyzed and integrated. Furthermore, this research develops. analyzes, and implements hybrid algorithms for solving them, which combine fast local heuristic approach with an optimization-based approach. In addition, various partitioning algorithms being able to deal with large fleet of vehicles are developed based on 'divided & conquer' technique. Simulation experiments are developed and conducted to evaluate the performance of these algorithms.

• Archives of design research
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• v.18 no.1 s.59
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• pp.135-144
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• 2005

Consumers' awareness of product value, and their product preferences, are becoming increasingly influential in product development, particularly in corporations' efforts in manufacturing products with a competitive edge. Corporations conduct surveys on consumers' product satisfaction and preferences and conduct in-depth studies on consumer needs. They then manufacture products in accordance with the results of these surveys and studies. With the necessity and demand for digital door lock products recently growing, this research sought to explore product competitiveness reinforcement factors that could facilitate market penetration, and to formulate corresponding design strategies. In-depth consumer interviews were also conducted to identify consumer lifestyles and needs. Furthermore, consumer preference images, purchase and use-related patterns, and the status of door lock markets were studied. In the past, to design and manufacture consumer-oriented products, corporations primarily resorted to the improvement of the products' technological features. At present, the users' product preferences and the ways that they use these products are the factors that determine product design. Consumers today tend to adjust their lifestyles according to available products, and prefer products that have greater value in terms of lifestyle and culture. Strategic points for reinforcing competitiveness were presented in this study: first, offering different values that will enhance consumer satisfaction, second, positively developing bio-recognizable methods that will boost consumer preference, third, meeting the consumers' expectations that door lock products should not be mere 'entrance and exit control' systems, but network security systems and fourth, adopting convenient authentication methods backed by advanced technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.19-24
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• 2020

The interest in renewable energy is increasing due to the depletion of fossil fuels. In particular, active research on wave power, which is highly predictable and abundant, is being conducted. The coaxial accelerator-type wave power generator used in this study was designed to improve the power generation efficiency by converting bidirectional linear motion into a rotational force. In an offshore engineering basin, waves were generated, and case tests were performed according to the wave period and wave height. The experimental results were verified by the theoretical method related to the frequency response, and the overall trend was confirmed to be consistent. These results are expected to be useful in estimating the power of wave generators and designing parameters to improve the efficiency of wave energy in the design stage before manufacturing. In addition, the manufacturer can predict the wave energy efficiency of wave generators, which can reduce the development time and cost by preventing trial and error processes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.95-101
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• 2017

In this paper, the sizing removal condition for the pretreatment of composite materials is obtained numerically by applying an image processing algorithm and nickel-plated carbon fiber is fabricated by a dry process method to enhance its electromagnetic shielding performance. Sizings that are wrapped in a polymer type material during the manufacturing of carbon fiber should be removed for dry coating. A numerical value, that is the correlation, can be obtained by determining the regular pattern of the carbon fiber in the image taken by a scanning electron microscope (SEM) after the sizing is removed. The application of the proposed numerical method to the SEM image of the fiber after the sizing is removed with solution, compressed air, solution and compressed air (hybrid), showed that this method of eliminating the sizing is superior to the hybrid method. Then, by spreading the carbon fiber roll with the sizing removed, we were able to produce nickel plated carbon fiber by the roll-to-roll sputtering method. The electromagnetic shielding performance of the fabricated 30, 40 and 100 nickel coated carbon fibers was measured. The Korea Advanced Institute of Science and Technology evaluated the electromagnetic shielding performance of the 100 nickel-coated carbon fiber to have a maximum value of 73.2 (dB) and a minimum value of 66.7 (dB). This is similar to the electromagnetic shielding rate of copper and shows that this material can be used as a cable for EV / HEV automobiles.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.102-108
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• 2013

In manufacturing of solution-processed organic electronic devices, a spin coating method is frequently used, but which has a big problem. Solvent in a solution has a decisive effect such as physical and chemical damage for successive solution-based film deposition. Such a severe damage by solvent restricts for fabricating building blocks of multi-layered films from solutions. In this work, it will be shown that a proper combination of well-known solvents gives a chance to fabricate multi-layered film, also this new method was applied to make organic field effect transistor. Two types of bottom gate, bottom contact transistors were fabricated, one of which is fabricated by conventional single spin coating method, the other fabricated by double spin coating method. Compared with the electrical characteristics in a single spin coated transistor, the leakage current between source and gate electrode was decreased, ON state current was increased, and the extracted saturation mobility was multiplied more than 2.7 time for double spin coated transistors. It is suggested that the multiple coated gate dielectric structure is more desirable for high performance organic ferroelectric field effect transistors.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.505-516
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• 2016

With the development of nanotechnology, nanomaterials are used in various fields. Therefore, the interest regarding the safety of nanomaterial use is increasing and much effort is diverted toward establishment of exposure assessment and management methods. Occupational exposure limits (OELs) are effectively used to protect the health of workers in various industrial workplaces. This study aimed to propose an OEL for domestic multi-walled carbon nanotubes (MWCNTs) based on animal inhalation toxicity test. Basic procedure for development of OELs was examined. For OEL estimation, epidemiological study and quantitative risk assessment are generally performed based on toxicity data. In addition, inhalation toxicity data-based no observed adverse effect level (NOAEL) and benchmark dose (BMD) are estimated to obtain the OEL. Three different estimation processes (NEDO in Japan, NIOSH in USA, and Baytubes in Germany) of OELs for carbon nanotubes (CNTs) were intensively reviewed. From the rat inhalation toxicity test for MWCNTs manufactured in Korea, a NOAEL of $0.98mg/m^3$ was derived. Using the simple equation for estimation of OEL suggested by NEDO, the OEL of $142{\mu}g/m^3$ was estimated for the MWCNT manufacturing workplace. Here, we used test rat and Korean human data and adopted 36 as an uncertainty factor. The OEL for MWCNT estimated in this work is higher than those ($2-80{\mu}g/m^3$) suggested by previous investigators. It may be greatly caused by different physicochemical properties of MWCNT and their dispersion method and test rat data. For setting of regulatory OELs in CNT workplaces, further epidemiological studies in addition to animal studies are needed. More advanced technical methods such as CNT dispersion in air and liquid should be also developed.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.3-11
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• 2013

As construction projects became larger and longer, the need for the construction technologies and innovative construction processes has been continuously increased in construction field. In response to this trend, construction industries tried to adopt the concurrent engineering which had been normally applied for manufacturing industries to develop the products with improved quality in a reduced time. However, the application of the concurrent engineering to construction field was limited due to the lack of advanced management system and incomplete theoretical backgrounds. In this regard, this study attempted to develop a checklist for the successful application of concurrent engineering to bridge projects. To this end, this study presents the checklist for the application of concurrent engineering to construction projects. Further, the checklist was modified and updated to reflect the specific feature of the bridge construction using expert interviews. With the help of additional 188 experts, a questionnaire-based survey was also conducted to validate the checklist. In addition, using importance-performance analysis(IPA), the study identified the factors needed for intensive improvement. Consequently, the proposed checklist is expected to be useful, because it improves the applicability of the concurrent engineering in that it enables managers to monitor construction progress and further to protect the project from potential risks.

• The Korean Journal of Emergency Medical Services
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• v.6 no.1
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• pp.103-128
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• 2002

As a result of trying the various manufacturing methods considering the reality of manpower and equipments with this manual, the following standardized procedures and contents can be suggested. (1) Since tools presenting Rock-Drill data must formalize the order of explanation although explainers are different, it will be valid that it is configured by existing power point method rather than by web document type. Composition of contents are selected on the basis of defence card and survey and then 8 items including initial screen, peripheral conditions, mobilization route, general conditions, use and structure by floor, department of vehicle consideration in activities and end screen are included. (2) Making methods and cautions of data included and used in power point are as follows ; - It was most effective that objects of fire fighting and location of neighboring fire fighting water were expressed by electronic map and drawing of inner building was made by scanning it after paining general architecture drawing(plan by each floor) rather than using drawing tools of EXCEL program or CAD drawing. And it was helpful to simplify contents of architecture drawing to wall, stairs and gate in understanding them. - Photographing of video data should be taken to show available fire fighting facilities in fire, use of planned space and the whole inner structure of each floor from the inside of fire fighting buildings and to display play time between 10 sec. and 1 min, for obstacles to distance from adjacent buildings or passage of special vehicles and fire fighting water from the outside of the building. - File format of video data taken in this way is most suitable to use wmv(window media video) or asf(advanced streaming format) type in consideration of time required for export, screen quality, file capacity and play type in Rock-Drill through network. - Still screen(photo) is more effective to express the department of fire fighting vehicles or other equipments than using video. (3) In configuration work of power point, hyper link was used most and configured to see any part at any situation like web document and then uniformity of presentation order of power point was complemented. (4) In case of sales facilities with the area of $35.557m^2$, the time of 22 hours and 30 minutes for five days was taken with five persons. Therefore, when eight-hour works a day were calculated, the whole process of video work for Rock-Drill can be finished with three day works.

• The Journal of Korean Medicine
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• v.27 no.3 s.67
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• pp.222-226
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• 2006

Objective: The aim of this study was to introduce newly developed cooperation group standards of acupuncture needles for single use and to make a contribution to the future development of Korean Industrial Standards (KS) of acupuncture needles for single use. Results and Conclusion: Quality assurance and quality control with high safety profile is one of the most critical issues in medical device manufacturing. Up to now, proper attention has not been paid to this issue with respect to acupuncture needles for single use and their related devices. We, therefore, organized a committee to make guidelines to produce an acupuncture needle with high quality and safety. In the committee, we reviewed the topic from an historical viewpoint, and investigated the current situation of the standardization of acupuncture needles in other developed countries. Finally, we developed the cooperation group standards in advance of development of KS on the acupuncture needles for single use. The standards are composed of 12 sections describing: Scope, Normative references, Definitions, Materials, Configuration, Appearance and Cleanliness, Quality, Sterilization and Safety, Processing of Surface and Coating Material, Test, Packaging, and Labeling. We hope that the standards would be useful guidelines to produce high quality acupuncture needles and play an important role in the development of KS in the future.