• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.135-141
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• 2018

Recently online e-commerce system is grew up rapidly comparing to offline commerce and is made up actively in all commerce field. Offline commerce is uneffective because it is very complicated for distribution structure and spend too much money. On the other hand, existing online e-commerce system is reluctant for purchase because of not having their confidence of fruit's freshness. Therefore in my paper, as e-commerce system based on IoT using each sensors, RFID tags and networks is suggested, consumer can see freshness of fruits and make order it by on-line having assurance of it. Also it shows that this objected-oriented analysis and design method is very useful for the build of common use system from now on.

• Advances in concrete construction
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• v.3 no.4
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• pp.283-293
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• 2015

This paper presents the effects of elevated temperatures of $400^{\circ}C$ and $800^{\circ}C$ on the residual compressive strength and failure behaviour of fibre reinforced concretes and comparison is made with that of unreinforced control concrete. Two types of short fibres are used in this study e.g., steel and basalt fibres. The results show that the residual compressive strength capacity of steel fibre reinforced concrete is higher than unreinforced concrete at both elevated temperatures. The basalt fibre reinforced concrete, on the other hand, showed lower strength retention capacity than the control unreinforced concrete. However, the use of hybrid steel-basalt fibre reinforcement recovered the deficiency of basalt fibre reinforced concrete, but still slightly lower than the control and steel fibres reinforced concretes. The use of fibres reduces the spalling and explosive failure of steel, basalt and hybrid steel-basalt fibres reinforced concretes oppose to spalling in deeper regions of ordinary control concrete after exposure to above elevated temperatures. Microscopic observation of steel and basalt fibres surfaces after exposure to above elevated temperatures shows peeling of thin layer from steel surface at $800^{\circ}C$, whereas in the case of basalt fibre formation of Plagioclase mineral crystals on the surface are observed at elevated temperatures.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.271-272
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• 2016

Owing to the development of information communication technology(ICT), there are many changes taking place in the agriculture sector. As an example, an effective agricultural activities with ICT have brought an increase in agricultural production. On the other hand, these technology investment activities are very costly. Until recently, the technology development has been made in agricultural technology development perspective. This view, however, has been changed to production increase in accordance with the crop growth conditions. In this paper, we propose a device which can maintain an optimal crop growing environment. It is economic by utilizing the existing facility of farmhouse and can reduce the cost of crop growth environment improvement.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.2
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• pp.14-20
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• 2011

The end of design lifetime for Wolsong unit 1 will be reached on 20th November in 2012. So the license renewal documents for the continuous operation of Wolsong unit 1 is under reviewing now. Major components of primary system such as pressure tubes, feeder pipes including delayed neutron monitoring system tubing are being replaced and many components of secondary system are also being repaired. In this paper, the assessment on the wear degradation of delayed neutron monitoring system tubing(on the other hand, DN tube was called) was performed for the ageing management of the same component. The wear defects of this component was one of causes that resulted in heavy water leakage accidents. Therefore design specifications of Wolsong uint 1 and heavy water leakage accidents of pressurized heavy water reactors were reviewed and causes of wear defect for DN tubes were analyzed. Wear propagation equations based on the heavy water leakage history were made and the proper repairing time was possible to be expected if the continued operation was considered. Finally design change items of DN tubes that were conducted for the long term operation of Wolsong unit 1 are introduced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.364-372
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• 2006

In this paper, we present a finger tip tactile sensor which can detect contact normal force as well as slip. The sensor is made up of two different materials, such as polyvinylidene fluoride (PVDF) known as piezoelectric polymer, and pressure variable resistor ink. In order to detect slip on the surface of the object, two PVDF strips are arranged along the normal direction in the robot finger tip and the thumb tip. The surface electrode of the PVDF strip is fabricated using silk-screening technique with silver paste. Also a thin flexible force sensor is fabricated in the form of a matrix using pressure variable resistor ink in order to sense the static force. The developed tactile sensor is physically flexible and it can be deformed three-dimensionally to any shape so that it can be placed on anywhere on the curved surface. In addition, a tactile sensing system is developed, which includes miniaturized charge amplifier to amplify the small signal from the sensor, and the fast signal processing unit. The sensor system is evaluated experimentally and its effectiveness is validated.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.95-104
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• 2002

The theoretical and analytical studies on dynamic signals(force and acceleration signals) measured at SPT rod are actively made. In this paper, the characteristics of stress wave(force signals) in SPT rod were studied experimentally using model rod system. It was noted that the amplitude ratios of reflected wave over incident wave in different end conditions were well matched with theoretical results. The impedance of soil could be determined if the characteristics of incident and reflected waves could be evaluated quantitatively in situ SPT test. On the other hand, the results of model tests showed that the effect of reflected wave caused by side friction was negligible, and therefore, the analysis model considering only end resistance of sampler could be applicable in dynamic analysis of SPT.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.21-28
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• 2009

This paper proposes RCBT(Reduced Compact Binary trie) to correct faults of CBT (Compact Binary trie). First, in the case of CBT, a compact structure was tried for the first time, but as the amount of data was increasing, that of inputted data gained and much difficulty was experienced in insertion due to the dummy nodes used in balancing trees. On the other hand, if the HCBT realized hierarchically, given certain depth to prevent the map from increasing onthe right, reached the depth, the method for making new trees and connecting to them was used. Eventually, fast progress could be made in the inputting and searching speed, but this had a disadvantage of the storage space becoming bigger because of the use of dummy nods like CBT and of many tree links. In the case of RCBT in this thesis, a capacity is increased by about 60% by completely cutting down dummy nods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.834-848
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• 2013

To effectively use these functions many kinds of human-phone interface are used such as touch, voice, and gesture. However, the most important touch interface cannot be used in case of hand disabled person or busy both hands. Although eye tracking is a superb human-computer interface method, it has not been applied to smartphones because of the small screen size, the frequently changing geometric position between the user's face and phone screen, and the low resolution of the frontal cameras. In this paper, a new eye tracking method is proposed to act as a smartphone user interface. To maximize eye image resolution, a zoom lens and three infrared LEDs are adopted. Our proposed method has following novelties. Firstly, appropriate camera specification and image resolution are analyzed in order to smartphone based gaze tracking method. Secondly, facial movement is allowable in case of one eye region is included in image. Thirdly, the proposed method can be operated in case of both landscape and portrait screen modes. Fourthly, only two LED reflective positions are used in order to calculate gaze position on the basis of 2D geometric relation between reflective rectangle and screen. Fifthly, a prototype mock-up design module is made in order to confirm feasibility for applying to actual smart-phone. Experimental results showed that the gaze estimation error was about 31 pixels at a screen resolution of $480{\times}800$ and the average hit ratio of a $5{\times}4$ icon grid was 94.6%.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.2 s.30
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• pp.109-116
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• 1989

Korean clothings are admired for their beauty and traditional value. On the other hand, many of Korean women complain of chest restriction. Korean skirts may give high garment pressure to the wearers because the Korean skirt-band do not resolve physical tensions in size or in stretch. This paper aims at the identification of the garment pressure caused by the Korean skirt-band and the cardiopulmonary change caused by garment pressure. The Korean skirt-band were made in 3 kinds of size, and 21 women were selected for wearing test. The garment pressure was measured in front, side, and back parts of the body. The measured cardiopulmonary parameters were vital capacity, respiratory rate, heart rate, and blood pressure. The results were as follows: 1. The smaller the size of the Korean skirt-band, the greater the garment pressure. The pressure during inspiration was significantly greater than the pressure during expiration. 2. The pressure in side part was the greatest of the three measurements and the pressure in back part was the smallest. 3. The small size of the Korean skirt-band revealed low vital capcity and great respiratory rate. 4. As the small size grement was dressed, the respiratory rate and the heart rate during walking and rest after walking were significantly high. 5. Subjects felt uncomfortable when they wore small sized garment.

• Journal of the Korea Furniture Society
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• v.26 no.3
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• pp.207-221
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• 2015

Inlay is a high technique of inlaying patterns on the surface of crafts and widely used transcending time and place at various hand crafting area. Inscribed pattern technique using rare materials in the area have been used by the artisans of artistic flair and functionality and its value is also highly regarded from ancient to modern and inherits and is being developed today. Existing inlay technique, however, has not been spread out because it needs craftsman's skill based on the handcraft and inscribed materials are very rare to use. This paper aims to replace natural wood Sanggam materials for traditional furniture patterns such as Samho Jang, Ohho Jang, Seongtoenoe Moon, Gyeopgwinoe Moon and wood inlay text like Soo (Long life), Bok (Luck), Kang (Peace), Ryoung (Relaxed) and gammadion cross pattern. Gathered black, yellow and white color dyed wood using power tools can replace rare natural inlay materials through reliable and standardized supply. Dyed-gathered inlay materials can easily replace wood inlay materials, therefore, attempt to create an improved direction regarding materials and fabrication techniques in order to make traditional or contemporary artistic furniture to be produced.