• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.227-232
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• 2008

Stirling engine for solar thermal power is an essential part of Dish-Stirling system which generates electricity by using direct normal irradiation and will go into commercialization in near future. For the Stirling engine used in this study is Solo 161 model the capacity of which is 10 kWe and was already used for the Dish-Stirling system of KIER in Jinhae. The receiver of Stirling engine absorbes concentrated solar radiation and transfer it to working fluid of Hydrogen. The working condition of striling engine is high temperature and high pressure to make high efficiency. Therefore the receiver should stand against high temperature of above 800 $^{\circ}C$ and high pressure of max. 150 bar with good performance of heat transfer. The receiver is composed of 78 Inconel tubes of 1/8" with thickness of 0.71 mm and two reserviors which is connected with two cylinders. In order to know the charaterristics of heat transfer of Stirling engine receiver, simulation on the heat transfer of the receiver of Solo 161 is conducted by using CFD code of Fluent. The heat flux on the receiver surface has a shape of Gaussian distribution so, it is necessary to simulate a whole receiver. However, It is difficult and time consuming to simulate the whole receiver that one tube with different heat flux conditions are considered in this study. From the simulation results, heat transfer charateristics of receiver are observed and tube wall and fluid temperature and heat transfer coefficient are obtained and compared with the calculated results from Dittus-Boelter's correlation.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.235-244
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• 2016

This study was conducted to verify seismic performance of special moment frame's joints at roof-level with high-strength concrete and SD600 bars. K-RC-H was designed according to the seismic code and K-HPFRC-H had 150% of the original hoop spacing and 1.0% steel fiber volume fraction compared with K-RC-H. Both specimens had remarkable seismic performance without noticeable decrease in moment, but with very good energy dissipation before rebar failure. The U-bars in the joint sufficiently constrained rebar's action that pushed the cover upward. SD600 bars with $1.25l_{dt}$ had minimum slip in the joint. It was considered that the steel fiber contributed to improvement of the bending moment and joint shear distortion, and the result showed that it would be possible to increase the hoop spacing to 150% of the regular spacing.

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.85-96
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• 2011

The access monitoring and control system of vehicles involved in construction logistics has been evolved from paper-based through bar code-based and to RFID-based management with pursuing automatic data collection and management. However, existing management methods have a limit that they still need manpower allocation for access control of vehicles. Therefore this research has proposed an framework that includes devices and an information system for effective and efficient data collection for access control of vehicles for construction logistics. And the proposed framework has been verified through a laboratory test using a prototype system developed in this research. It is expected that the installation methods of RFID antenna and tag for the framework could be applied to not only the access control of construction site but also various RFID applications at construction sites.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.520-523
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• 2010

In the field of network sense for the Ubiquitous environment, the technology of RFID is a significant part. Due to the real time processing of information and the property of network, RFID has been used in service field such as distribution, administrative control of physical distribution, remote measuring device, and security, instead of currently used bar-code. The management system of port facilities using the current RFID technology has the effects of reducing working hours and improvement in data processing, but it is not proper for human resource allocation since it is dominantly worked for physical resources. In this paper, we designed and implemented personnel control system using RFID of 2.4GHz in port facilities which presents a monitoring system for safety operation and increase of efficiency using RFID in order to overcome the limitations and problems of current port operation management techniques.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.566-572
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• 2011

In recent semiconductor and FPD (Flat Panel Display) manufacturing processes, high clean-class delivery operation is required more and more for short working time and better product quality. Traditionally SLIM (Single-sided Linear Induction Motor) is widely used in the liner drive applications because of its simplicity in the rail structure. A magnetically levitated (Maglev) unmanned vehicle with SLIM traction, which is powered by a CPS (Contactless Power Supply) can be a high precision delivery solution for this industry. In this paper unmanned FPD-carrying vehicle, which can levitate without contacting the rail structure, is suggested for high clean-class FPD delivery applications. It can be more acceptable for the complex facilities composed with many processes which require longer rails, because of simple rail structure. The test setup consists of a test vehicle and a rounded rail, in which the vehicle can load and unload products at arbitrary position commanded through wireless communications of host computer. The experimental results show that the suggested vehicle and rail have reasonable traction servo and robust electromagnetic suspensions without any contact. The resolution of point servo errors in the SLIM traction system is accomplished under 1mm. The maximum gap error is ${\pm}0.25mm$ with nominal air gap length of 4.0mm in the electromagnetic suspensions. This type of automated delivery vehicle is expected to have significant role in the clean delivery like FPD glass delivery.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.60-67
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• 2008

At present, RFID system is highly welcomed as a substitute system with its bar code recognition system and self recognition equipment. Consequently, the system has multi applications and can be complementing to its security. In particular, RFID system is significantly related with electronic transaction equipments : transportation card, ID card in check point, attendance sheet. Based upon these characteristic, the system is becoming extremely popular in the field of logistics, harbor and stock management, animal control and product circulation & distribution. In this dissertation, I would like to present a more efficient and stable remote entry control system with the network-based TCP/IP. It is a simple example of ubiquitous computing function. Above all, approved protocol system should be applied to the remote entry control function. Its efficient function with the applied approval protocol based-remote entry control system should be confirmed. Therefore, a preliminary test should be prerequisite in automatic entrance function with the embedded and TCP/IP-based RFID system.

• Journal of KIISE:Software and Applications
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• v.36 no.7
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• pp.560-570
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• 2009

RFID, Radio Frequency Identification, is a technology of automated identification replacing bar-code. RFID technology has advantages that it recognizes fast and it is strong to contamination using wireless communication. However, there are difficult problems that should be solved for popularization of RFID. Among of these, tag anti-collision problem is dealed in this paper. It affected the performance of RFID system directly. This paper analyzes conventional algorithms and proposes new algorithms of tag anti-collision. The algorithm proposed was composed of appropriate properties to each phase of distribution and recognition as hybrid between ALOHA-based algorithm and QT-based algorithm. At phase of distribution, the number of tags recognizing at a frame was reduced using ALOHA-based algorithm. It addressed the delay problem because of deep depth of tree. At phase of recognition, it solved ALOHA-based chronic problem that couldn't recognize all the tags sometimes. Moreover, QTR algorithm that recognize by reversed tag IDs was adopted for the performance. The FQTR algorithm proposed in this paper showed brilliant performance as compared with convention algorithms by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1845-1852
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• 2015

From bar code systems and radio frequency identification (RFID) to beacons utilizing low power bluetooth technology, the fusion of information technology and health and medical treatment is spreading through advances such as automated treatment and examination stages and the use of treatment information connected to smart devices. In this paper, designed and implemented a mobile health care system for the safe management of blood transfusions to prevent accidental problems that can occur during patient blood transfusions. It makes safe and effective blood transfusion possible by using smart devices to read information saved on patient bracelets, blood-collecting containers, blood transfusion bags, and medical personnel identification cards so that they match patient information. By applying the blood transfusion management mobile health care system presented and implemented in this paper to blood transfusion processes in hospitals, it was verified that it allows for safe and effective blood transfusion, preventing accidents which may occur in blood transfusion processes.

• Convergence Security Journal
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• v.7 no.2
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• pp.81-89
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• 2007

Mobile computing environment that support so that can offer employees inside information that enterprise has always improves business productivity and fetches efficiency enlargement. In this paper, limit model that can process ERP information by real-time as easy and convenient always utilizing radio network and PDA, Mobile camera based on Mobile vision concept. Calculable information between seller and customer is supplied supplying real-time brand image and information by practical use of Enterprise Resource Planning doing based on Mobile. Technical development and commercialization that utilize mobility, enforcement stronghold, portability etc. that is advantage of Mobile communication are required. In this paper, mobility of precious metals.jewel field that use portable terminal equipment taking advantage of a Mobile technology is secured. Constructed Mobile vision system that satisfy photography and bar-code scan at the same time from Mobile camera.

• Journal of the Korea Concrete Institute
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• v.25 no.2
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• pp.165-173
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• 2013

Splice sleeves for HD25 and HD32 rebars with yield strength 500 MPa were studied experimentally and analytically. The shapes of sleeve was examined with nonlinear finite element analyses. A total of 18 specimens were tested with test variables of rebar types, sleeve lengths, mortar compressive strengths, and rebar development lengths. Three identical specimens per each variable were tested in order to prevent any test errors. After tests, numerical studies with a nonlinear finite element method were conducted to evaluate the test results. Experimental studies with 18 specimens showed that the sleeves of this study satisfies the code requirement. It was found that the strength of mortar and the bar development length within the sleeves did not affect to the load-carrying capacity of sleeves.