• 한국해양학회지
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• v.19 no.2
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• pp.133-140
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• 1984

Oceanographic applications of digital filters are studied with special emphasis on the convolution filter with Hamming window and the recursive filters. Convolution filters are simple to understand and easy to design but not efficient for a long data set. Recursive filters, despite of the complexities, have advantages on economy and filter characteristic. By means of digital filtering technique we find that the alongshore wind at Pusan and the sea surface temperature at Gampo in summers during 1973 to 1979 are negatively correlated at low frequencies (periods longer than 5 days) but not so at high frequencies.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.61-65
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• 2014

The study aimed at determining the feasibility of three portal totally Laparoscopic cryptorchidectomy in small breed dogs. Four right sided and one left sided abdomen retained testicles in five dogs weighing 2.2~8.7 kg were retrieved successfully. Pampiniform plexus and vas deference were ligated and transected with Hem-o-lock/monopolar electrocauterization (1/5), or ultrasonic scalpel (4/5) and the latter provided more easy, quick and safe hemostasis and transection. The resected testis was easily removed through a insertion site. Mean surgical time was $19.9{\pm}15.2$ minutes and when the abdominal cavity was explored again, there were no major complications. The patient recovered favorably without unwilling events. This is the case report of laparoscopic cryptorchidectomies in small breed dogs weigh less than 10 kg. Laparoscopic cryptorchidectomy could be considered as an alternative in small animal surgery.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.37-44
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• 1997

Barium ferrite thin films on the thermal oxidized Si substrate were prepared by using sol-gel method (dip coating) from the sol of composition ratio of 5.25, designated by mole ratio 2Fe/Ba. The gelation process was largely divided into 4 step, and the sol prepared by reaction for 90 minutes at 8$0^{\circ}C$ was the suit-able for coating. Needle shaped particles formed on the coating layer were placed parallel to substrate and the inclination was increased with film thickness. The easy-direction of magnetization of needle shaped par-ticles was long-axis direction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.5
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• pp.437-443
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• 2008

In this paper, analysis and control of the flexible multibody system using MATLAB is presented. The equations of motion of a flexible body are derived in terms of the modal coordinate. The rigid-flexible multibody dynamic solver is developed. Finite element information required to analyze motion of flexible bodies is imported from ANSYS. The modified finite element data, such as modal mass matrix, modal stiffness matrix and constraint mode shapes, is calculated in the solver. Since the solver is developed using MATLAB, it is very easy to connect with SIMULINK which is widely used to control motion of the multibody system. Several simulations are implemented to verify the developed solver. A control example is carried out and the usefulness of the developed solver is demonstrated.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.460-460
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• 2014

Organic photovoltaic cells (OPV) have been extensively studied due to their unique properties such as flexibility, light-weight, easy processability, cost-effectiveness, and being environmental friendly. These advantages make them an attractive candidate for application in various novel fields and promising development with new features. Photovoltaic cell-integrated textiles have greatly attractive features as a power source for the smart textile solutions, and OPV is most ideal form factor due to advantage of flexibility. In this study, we develop a textile-based OPV through various experimental methods and we suggest the direction for the design of the photovoltaic textile. We used a textile electrode and tried to various layouts for textile-based OPV. Finally, we determined the contact area by using Hertzian theory for the calculation of power conversion efficiency (PCE). Based on the results of calculation, the short circuit current density, Isc, was $13.11mA/cm^2$ under AM 1.5condition and the PCE was around 2.5%.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1317-1326
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• 2017

The cascaded H-bridge (CHB) multilevel converter is a promising topology for large-scale photovoltaic (PV) systems. The output voltage over-modulation derived by the inter-module active power imbalance is one of the key issues for CHB PV systems. This paper proposed a dynamic power distribution strategy to eliminate the over-modulation in a CHB PV system by suitably redistributing the reactive power among the inverter modules of the CHB PV system. The proposed strategy can effectively extend the operating region of the CHB PV system with a simple control algorithm and easy implementation. Simulation and experimental results carried out on a seven-level CHB grid-connected PV system are shown to validate the proposed strategy.

• International Journal of Contents
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• v.5 no.4
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• pp.88-93
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• 2009

It is important for communication networks to possess the capability to overcome failures and provide survivable services. We address modeling and analysis of performability affected by both performance and availability of system components for a token ring network under failure and repair conditions. Stochastic reward nets (SRN) is an extension of stochastic Petri nets and provides compact modeling facilities for system analysis. In this paper, hierarchical SRN modeling techniques are used to overcome state largeness problem. The upper level model is used to compute availability and the lower level model captures the performance. And Normalized Throughput Loss (NTL) is obtained for the composite ring network for each node failures occurrence as a performability measure. One of the key contributions of this paper constitutes the Petri nets modeling techniques instead of complicate numerical analysis of Markov chains and easy way of performability analysis for a token ring network under SRN reward concepts.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.51-59
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• 2009

Many failures are due to incorrectly programmed transactions and data entry errors. System failure causes the loss or corruption of the contents of volatile storage. Although global processing protects data values to detect direct or indirect information effluence, security environments are very important in the recovery management of heterogeneous systems. Although transaction can't control system fault, the restart for the system can cause information effluence by low bandwith. From various faults, it is not easy to maintain the consistency and security of data. This paper proposes recovery management protocols to assure global multilevel secure one-copy quasi-serializability in security environments of heterogeneous systems with replicated data and proves its correctness. The proposed secure protocols guarantee the reliability and security of system when the system fault is happened.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.295-301
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• 2004

Satellite captures images periodically and economically over the area wider than aerial photographs, and reconnaissance to unapproachable area. For these advantages, mapping using high resolution satellite image has high potentials of marketability and development. Therefore, utilization of satellite image in mapping and GIS is expected to be growing and research on describable feature, positional accuracy and, possible mapping scale is urgently needed. This research presented that Quick Bird orthoimage could be used to update digital map on a scale of 1:5,000. Quick Bird image was corrected geometrically based on ground control points. DEM was generated using height data of digital topographic map. The orthoimge was produced by digital differential rectification based on DEM which was generated using height data of digital topographic map(scale 1;5,000 and 1;1,000). When the digital topographic map was overlaid with the orthoimage, it was very easy to find changed region or new features builded after the map compiled.

• Journal of Construction Engineering and Project Management
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• v.5 no.2
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• pp.35-43
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• 2015

Project Management Consultant (PMC) plays a vital role in the overall performance of any project. Selecting right PMC for right project is the most crucial challenge for any construction owner. Thus, PMC selection is one of the main decisions made by owners at the early phase of construction project. It is not easy for the project owner to select a competent PMC due to the fuzziness, imprecision, vagueness, incomplete and qualitative criteria of the decision. This paper presents a model for selecting PMC contractor using the Fuzzy Analytical Hierarchy Process (FAHP). And a fuzzy number based framework is proposed to be a viable method for PMC contractor selection. A case study to illustrate the application of the model is also presented in this paper.