• Korean Journal of Optics and Photonics
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• v.16 no.1
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• pp.50-55
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• 2005

A method for measuring the wavefront error and the modulation transfer function(MTF) of large aperture optics using an unequal path interferometer is presented. A bidirectional shearing interferometer is used for collimation testing of the measurement system. A large aperture Fizeau interferometer with long optical path difference measures the wavefront error of the optics under test by using a $\Phi$ 400 mm off-axis parabolic mirror. The MTF is also measured at the wavelength of the interferometer by changing the laser light into partially incoherent light. Test results of a $\Phi$ 300 mm Cassegrain type satellite telescope made in Korea are presented.

• Korean Journal of Optics and Photonics
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• v.16 no.1
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• pp.56-62
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• 2005

Because of the wide plane and the curved field of CRT rear projection high definition television, its MTF(modulation transfer function) can't be easily measured by the usual forward testing method. Then we propose a backward testing method for the MTF so that the object plane and the image analyzer of forward testing are located at positions opposite each other. We prefer to use the backward testing method because the forward testing method has poor accuracy caused by very small numerical aperture, low spatial resolutions, and long depth of focus. We found that the backward testing method was very easy to align and had high repeatability. We confirmed the confidence of results obtained by the backward testing method in comparison with designed results.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.11-20
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• 2015

In this paper, we propose a context awareness system to transfer accurate information of the app store based on collective intelligence. By using collective intelligence the system minimizes the errors that could occur when an individual process the problems, recommends APIs for developers and builds the app store for not only customers but also developers. In addition, this system applies the ontology technique to aware the context of consumers, recommends the app suitable for the consumer and provides the information for app developers. By utilizing the deduction technique of the Jena, the context awareness system infers the context of a consumer and constructs the app store system which improves the existing app stores. In the point of service transfer and accuracy, the proposed app store system module show better performance than the existing app store.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.415-420
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• 2005

LMTT (Linear Motor-based Transfer Technology) is the horizontal transfer system for yard automation, which has been proposed to take the place of AGV (Automated Guided Vehicle) in the maritime container terminal. The system is based on PMLSM (Permanent Magnetic Linear Synchronous Motor) that consists of stator modules on the rail and shuttle car. It is desirable to reduce the weight of LMTT in order to control the electronic devices with minimum energy. In this research, structural optimization for a mover of shuttle car is performed to minimize the weight satisfying design criteria. The objective function is set up as weight. On the contrary, the design variables are transverse, longitudinal and wheel beams' thicknesses and its height, and the constraints are considered as strength and stiffness.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.4
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• pp.317-323
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• 2001

DICOM(Digital Imaging and Communications in MediCine), standard of medical image operation, present the methods for communications and Storage of Medical Image. medical image acquired from patient in hospital made DICOM files. this paper purposes design and implementation methodologies of a web-based medical information system that consists of DICOM (Digital Imaging and Communications in Medicine) databases and functional components of a web server in order to support the access of medical information with Intemet web browser. we store the patient and image information to database using reading the group and element oJ DICOM file. we made file transfer module by implementing DICOM Store service, in result, we can transfer DICOM file to IF based host or computer. We compose web component of communications and Storage service, user be used DICOM Service by web Browser.

• International journal of advanced smart convergence
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• v.7 no.4
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• pp.50-56
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• 2018

The Internet of Things (IoT) and Visible Light Communication (VLC) is opening up new services in lighting industry by integrating sensory network features in addition to standard illumination functionality. In this progressive developments, the next generation lighting devices for smart homes are capable to sense the environmental conditions and transfer the captured data through lights to gateway controller to access remotely. The smart home environmental sensor information's are few kbps only so VLC systems need to built-in with low rate light connectivity to transfer data to the gateway. To provide error free communication, the quality of a received light signal is important to be considered when designing an VLC receiver. Therefore, this paper proposes the design of robust low rate IoL receiver design using NCP302 voltage detector for micro controller to adapt the IoT/IoL front end module for system integration. To evaluate the proposed system performance, the Arduino UNO based IoT/IoL controller designed with lighting, sensors and lights connectivity interfaces. The experimental result shows that the robust interference rejection is feasible on proposed VOL receiver and possible to have an error-free communication up to 10 kbps at a low SNR using OOK modulation.

• Smart Structures and Systems
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• v.30 no.2
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• pp.159-172
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• 2022

To improve the accuracy of the standard penetration test (SPT) results, smart measurement system, which considers the energy transfer ratio into the sampler (ETR_Sampler), is required. The objective of this study is to evaluate the effects of joints and rod length on the transferred energy into the sampler. The energy transfer ratios into the rod head (ETR_Head) and ETR_Sampler, and the energy ratio from the head to the sampler (ER_HS) were obtained using energy modules, which were installed at the rod head and above the SPT sampler. Linear regression analyses are conducted to correlate the ER_HS with the number of joints, rod length, and SPT N-values. In addition, the dynamic resistances are calculated using both transferred energies into the rod head and into the sampler, and are compared with the corrected cone tip resistance measured from the cone penetration test (CPT). While the ETR_Head are generally constant, but the ETR_Sampler and ER_HS gradually decrease along the depth or the number of joints, except at certain depths with high SPT N-values. Thus, the ER_HS can be estimated using the number of joints, rod length, and SPT N-values. The dynamic resistance evaluated by E_Sampler produces a better correlation with the corrected cone tip resistance than that by E_Head. This study suggests that transferred energy into the SPT sampler may be effectively used for more accurate subsurface characterization.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.999-1008
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• 2023

Deformed fuel rods can cause a partial blockage of the flow area in a subchannel. Such flow blockage will influence the core coolant flow and further the core heat transfer during the reflooding phase and subsequent severe accidents. Nevertheless, most of the system analysis codes simulate the accident process based on the assumed flow blockage ratio, resulting in inconsistencies between simulated results and actual conditions. This paper aims to study the influence of flow blockage in severe accident scenario of the CAP1400 reactor. First, the flow blockage model of ISAA code is improved based on the FRTMB module. Then, the ISAA-FRTMB coupling system is adopted to model and calculate the QUENCH-LOCA-0 experiment. The correctness and validity of the flow blockage model are verified by comparing the peak cladding temperature. Finally, the DVI Line-SBLOCA accident is induced to analyze the influence of flow blockage on subsequent CAP1400 reactor core heat transfer and core degradation. From the results of the DVI Line-SBLOCA accident analysis, it can be concluded that the blockage ratio is in the range of 40%-60%, and the position of severe blockage is the same as that of cladding rupture. The blockage reduces the circulation area of the core coolant, which in turn impacts the heat exchange between the core and the coolant, leading to the early failure and collapse of some core assemblies and accelerating the core degradation process.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.123-132
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• 2005

In this Paper, we present an improvement of switch node for wavelength multiplex optical network. Currently because of quick increase of internet traffic a big network capacity is demanded. Wavelength multiplex optical network Provides the data transfer of high speed and the transparent characteristic of the data. Therefore optic network configuration is the most powerful technology in the future. It will be able to control the massive traffic from the optical network in order to transmit the multimedia information of very many quantify. Consequently the node where the traffic control is Possible, is demanded. The optical switch node which manages efficiently the multiple wavelength was Proposed. This switch is composed of a optical switch module for switching and a wavelength converter module for wavelength conversion. It will be able to compose the switch fabric without optical/electro or electro/optical conversion using optical MEMS(Micro Electro Mechanical Switches) module. Finally, we present the good test result regarding the operational qualify of the switch fabric and the performance of optical signal from the switch node. The proposed switch node of the optic network will be able to control the massive traffic with all optical.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.659-666
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• 2006

Servo-motors are used as key components of automated system by performing precise motion control as accurate positioning and accurate speed regulation in response to the commands from computers and sensors. Especially, the linear brushless servo-motors have numerous advantages over the rotary servo motors which have connection with the friction induced transfer mechanism such as ball screws, timing belts, rack/pinion. This paper proposes an estimation method of unknown motor system parameters using the informations from the sinusoidal driving type linear brushless DC motor dynamics and outputs. The estimated parameters can be used to tune the controller gain and a disturbance observer. In order to meet this purpose high performance Digital Signal Processor, TMS320F240, designed originally for implementation of a Field Oriented Control(FOC) technology is adopted as a controller of the liner BLDC servo motor. Having A/D converters, PWM generators, rich I/O port internally, this servo motor application specific DSP play an important role in servo motor controller. This linear BLDC servo motor system also contains IPM(Intelligent Power Module) driver and hail sensor type current sensor module, photocoupler module for isolation of gate signals and fault signals.