• Economic and Environmental Geology
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• v.33 no.2
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• pp.139-146
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• 2000

Development of an effective liner by utilization of the tailings frm the Imcheon mine and polymer has been tried. The tailings piled in the Imcheon mine, whose true specific gravity is about 2.86, are composed mainly of quartz, alkali-feldspar, muscovite and pyrite, and mostly (93.7% in volume) coarser than sand grain size (50${\mu}{\textrm}{m}$). Strength, leaching and permeability tests have been performed on the test specimens of polymer concrete manufactured with various mixing proportions of tailings, unsaturated polyester resins(UPR), calcium carbonates, stone powder sludges and granite soils. Polymer concrete specimens with stone powder sludges or granite soils as fillers and aggregates indicate 2.5 to 3 fold higher flexural and compressive strengths and lower permeabilities than those with calcium carbonates, which shows their usability as a waterproof liner. Also, the polymer concrete liner with stone powder sludge fillers is more advisable in aspects of utilization of waste sludges than that with other fillers.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1451-1464
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• 2015

Recently, in recognition of their outstanding structural performance, the use of Concrete Filled Steel Tube (CFT) columns has been increased. New shape welded built-up square tube was developed by the authors for broader usability using thin steel plates which were bent to be L-shaped (Channel) and each unit members were welded to form square steel tube as an cost-efficient use of expensive steel. In addition, since the rib placed at the center of the tube width acts as an anchor; higher load capacity of buckling is achievable. In order to apply the new shape built-up square columns, the structural behavior and stress distribution with parameter width of thickness (b/t), with and without rib were predicted. The New shape welded built-up square tube effectively delayed the local buckling of the steel tube, which led to a greater strength and ductility than regular HSS.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1173-1178
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• 2005

This paper proposes an IPMC actuating system with a bio-mimetic function. EMG signals generated by an intended contraction of muscles in forearm are used for the actuation of the IPMC. To obtain higher actuation force of the IPMC, the single layered as thick as 800 [${\mu}$m] or multi-layered IPMC (Nafion) of which each layer can be as thick as 178 [${\mu}$m] are prepared. The experimental results using an implemented IPMC control system show a possibility and a usability of the bio-mimetic artificial muscle.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.12
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• pp.1545-1551
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought. Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally under a real-time operating system environment, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.222-230
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• 2005

This article presents a field evaluation of an IP-based architecture for heterogeneous environments that has been developed under the aegis of the Moby Dick project, covering UMTS-like (universal mobile telecommunications system) TD-CDMA (time division-code division multiple access) wireless access technology, wireless and wired LANs. The architecture treats all transmission capabilities as basic physical and data-link layers, and replaces all higher-level tasks by IP-based strategies. The Moby Dick architecture incorporates mobile IPv6, fast handovers, AAA-control (authentication, authorisation, accounting), charging and quality of service (QoS) in an integrated framework. The architecture further allows for optimised control on the radio link layer resources. It has been implemented and tested by expert users, and evaluated by real users on field trials with multiple services available.

• ETRI Journal
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• v.38 no.6
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• pp.1104-1113
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• 2016

Non-linear document navigation refers to the process of repeatedly reading a document at different levels to provide an overview, including selective reading to search for useful information within a document under time constraints. Currently, this function is not supported well by small-screen tablets. In this study, we propose the concept of structure-aware touch-based scrolling (SATS), which allows structural document navigation using region-dependent touch gestures for non-sequential navigation within tablets or tablet-sized e-book readers. In SATS, the screen is divided into four vertical sections representing the different structural levels of a document, where dragging into the different sections allows navigating from the macro to micro levels. The implementation of a prototype is presented, as well as details of a comparative evaluation using typical non-sequential navigation tasks performed under time constraints. The results showed that SATS obtained better performance, higher user satisfaction, and a lower usability workload compared with a conventional structural overview interface.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.995-998
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process model.

• Journal of Information Technology Services
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• v.7 no.4
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• pp.301-317
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• 2008

Product-related services in manufacturing industry are different from typical services in service industry. Product-related services ensure proper product functioning, provide additional repurchase, and offer attractive margin Product-related services in manufacturing industry are not core activity but taking supporting roles, while services in typical service industry are core parts. The purpose of this study is to investigate the role of communication in linking IT and product-related logistics service in manufacturing industry. The relationships among IT, communication, logistics service and business performance are explored using a path analysis. The empirical research reveals that higher degree of IT usability leads to increased communication, and in turn, communication affects logistics service, and ultimately business performance. In addition, this study shows communication plays an intermediate role in linking IT to logistics service.

• Journal of Korea Multimedia Society
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• v.22 no.4
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• pp.424-431
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• 2019

In this paper, we propose a real-time hand gesture recognition algorithm to eliminate the inconvenience of using hand controllers in VR applications. The user's 3D hand coordinate information is detected by leap motion sensor and then the coordinates are generated into two dimensional image. We classify hand gestures in real-time by learning the imaged 3D hand coordinate information through SSD(Single Shot multibox Detector) model which is one of CNN(Convolutional Neural Networks) models. We propose to use all 3 channels rather than only one channel. A sliding window technique is also proposed to recognize the gesture in real time when the user actually makes a gesture. An experiment was conducted to measure the recognition rate and learning performance of the proposed model. Our proposed model showed 99.88% recognition accuracy and showed higher usability than the existing algorithm.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.601-608
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• 2007

The aim of this study was to evaluate the effect of mouthrinse products containing deep sea water. We used original deep sea water(DSW) and processed deep sea water desalinated by reverse osmosis at one time(DDW-1), by reverse osmosis at two times(DDW-2) and concentrated by reverse osmosis(CDW). We made 2 kinds of mouthrinse products containing CDW and other agents for smell and taste and one product without deep sea water. The negative control was distilled water. In vivo study, the dental plaque index scores and the gingival index scores were reduced after 4 weeks mouthrinsing three times daily with 4 kinds of deep sea water and 3 kinds of mouthrinse products(p<0.05). The pH of dental plaque in 1 minute after mouthrinsing was not higher than 5.5 in all solutions, but the pH in 20 minutes after mouthrinsing was higher than 5.7 in DSW, CDW and 3 kinds of products which had higher mineral contents. In vitro study, the mouthrinse solutions containing the higher mineral contents were also the more effective in reduction of methyl mercaptan which is one of the causes of halitosis. The 2 kinds of products containing deep sea water killed Streptococcus mutans(ATCC 25175) in culture plates in one minute. These results indicate the usability of deep sea water in mouthrinses for oral hygiene management.