• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.172-180
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• 2003

Based on simulation results and accompanying analysis, we suggest a thyristor-type ESD protection device structure suitable for implementation in standard CMOS processes to reduce the parasitic capacitances added to the input nodes, which is very important in CMOS RF ICs. We compare DC breakdown characteristics of the suggested device to those of a conventional NMOS protection device to show the benefits of using the suggested device for ESD protection. The characteristic improvements are demonstrated and the corresponding mechanisms are explained based on simulations. Structure dependencies are also examined to define the optimal structure. AC simulation results are introduced to estimate the magnitude of reduction in the added parasitic capacitance when using the suggested device for ESD protection. The analysis shows a possibility of reducing the added parasitic capacitance down to about 1/40 of that resulting with a conventional NMOS protection transistor, while maintaining robustness against ESD.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.134-147
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• 1999

The DNS provides naming services which are the basis for the application of the Internet and the security of the DNS should be provided for the security of the Internet. Recently IETF proposed a method which guarantees the integrity of DNS database contents and DNS queries/replies and distributes host public keys. In this paper we describe the design and implementation of the secure DNS which is built based on the IETF proposal and extended to facilitate its sue and management. In the extended secure DNS, DNS servers are used ad the directory system in a public key infrastructure and stores/distributes user public key certificates. The Web-based management interface and security log functions are added and the extended secure DNS is being built so that new cryptographic algorithms can be easily added.

• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.23-29
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• 2002

The design of data processing of GIS requires efficient method with analysis procedure. This system is easy to be used and managed for presenting route according to conditions as a graphic user interface environmental window system by applying three tiers based object-oriented method. The tier of data is in charge of a class for the exchange, extraction and conservation of data between GeoMedia and application tiers. A route selection algorithm was applied to application tiers, considering all conditions which are necessary for the route selection between a beginning point and an end point, and it was added by module such as data handing, road condition, buffering, clothoid and AHP to select the alternative route followed by new condition. The user tier can express the data acquired by an application tier. Thus three tiers based architecture was presented by implementing design of GIB data processing for its efficiency.

• The Journal of Korean Association of Computer Education
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• v.15 no.3
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• pp.1-10
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• 2012

The flow of computer education in modern knowledge and information society contains the computer science courses to cultivate the higher-level thinking abilities such as logical thinking skills, creativity, and problem-solving ability of learners. The purpose of this study is to recognize the need to promote the algorithmic thinking power to improve the problem solving ability of learners, to design the algorithm class based on the anchored instruction strategy for elementary school students and to verify the effectiveness. Anchored instruction model and cases are added to the class. Elementary school students were subjects and divided into a control group in which the traditional algorithm teaching method was conducted and an experimental group in which algorithm class was conducted applying anchored instruction. As results, an experimental group has shown improvements on problem solving compared to a control group.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.377-383
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• 2021

In this paper, we describe the case of automatic test equipment development for hardware verification of stores management computer mounted on aircraft. Recently, the required functions of aircraft have been diversified and the related technologies of avionics equipment have developed, and the types and quantity of interfaces required for avionics equipment have increased. In addition to the existing old stores, the stores management computer also needs to control the interface in large quantities as the requirements for the new stores are added. For this reason, the time and manpower required for the inspection of avionic equipment are also increasing, and if the test process of avionic equipment can be automated and unmanned, more efficient inspection system operation will be possible. Therefore, this paper introduces the case of designing test software and test scenario to automate the structural design contents and verification process of test equipment required for the verification of hardware function of stores management computer.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1431-1445
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• 2022

We construct a deep neural network model named ECGResNet. This model can diagnosis diseases based on 12-lead ECG data of eight common cardiovascular diseases with a high accuracy. We chose the 16 Blocks of ResNet50 as the main body of the model and added the Squeeze-and-Excitation module to learn the data information between channels adaptively. We modified the first convolutional layer of ResNet50 which has a convolutional kernel of 7 to a superposition of convolutional kernels of 8 and 16 as our feature extraction method. This way allows the model to focus on the overall trend of the ECG signal while also noticing subtle changes. The model further improves the accuracy of cardiovascular and cerebrovascular disease classification by using a fully connected layer that integrates factors such as gender and age. The ECGResNet model adds Dropout layers to both the residual block and SE module of ResNet50, further avoiding the phenomenon of model overfitting. The model was eventually trained using a five-fold cross-validation and Flooding training method, with an accuracy of 95% on the test set and an F1-score of 0.841.We design a new deep neural network, innovate a multi-scale feature extraction method, and apply the SE module to extract features of ECG data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.352-355
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• 2013

In this paper, a high power tuneable resonator for a wireless power transfer system based on magnetic resonance is proposed. A spiral structure is used for a self-resonant coil and tuneable trimmer capacitors are added at the edges of resonant coils such that the frequency can be easily tuned. 3D simulation tools and equivalent circuit modeling method are used for predicting self-resonant frequency and scattering parameters according to the change of capacitor values. From the measurement of the prototype WPT system, the resonant frequency could be controlled from 3.0 MHz to 4.5 MHz and the transmission efficiency way over 50 % when the distance between transmitting coil and receiving coil was 160 mm.

• ETRI Journal
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• v.36 no.2
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• pp.214-223
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• 2014

A fully-integrated penta-band reconfigurable power amplifier (PA) is developed for handset Tx applications. The output structure of the proposed PA is composed of the fixed output matching network, power and frequency reconfigurable networks, and post-PA distribution switches. In this work, a new reconfiguration technique is proposed for a specific band requiring power and frequency reconfiguration simultaneously. The design parameters for the proposed reconfiguration are newly derived and applied to the PA. To reduce the module size, the switches of reconfigurable output networks and post-PA switches are integrated into a single IC using a $0.18{\mu}m$ silicon-on-insulator CMOS process, and a compact size of $5mm{\times}5mm$ is thus achieved. The fabricated W-CDMA PA module shows adjacent channel leakage ratios better than -39 dBc up to the rated linear power and power-added efficiencies of higher than around 38% at the maximum linear output power over all the bands. Efficiency degradation is limited to 2.5% to 3% compared to the single-band reference PA.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.4
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• pp.261-271
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• 2002

The fluid-elastic instability analysis of the U-tube bundle inside the steam generator is very important not only for detailed design stage of the SG but also for the change of operating condition of the nuclear powerplant. However the calculation procedure for the fluid-elastic instability was so complicated that the consolidated computer program has not been developed until now. In this study, the numerical calculation procedure and the computer program to obtain the stability ratio were developed. The thermal-hydraulic data in the region of secondary side of steam generator was obtained from executing the ATHOS3 code. The distribution of the fluid density can be calculated by using the void fraction, enthalpy, and operating pressure. The effective mass distribution along the U-tube was required to calculate natural frequency and dynamic mode shape using the ANSYS ver. 5.6 code. Finally, stability ratios for selected tubes of the CE type steam generator were computed. We considered the YGN 3.4 nuclear powerplant as the model plant, and stability ratios were investigated at the flow exit region of the U-tube. From our results, stability ratios at the central and the outside region of the tube bundle are much higher than those of other region.

• Journal of Fashion Business
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• v.17 no.3
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• pp.30-47
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• 2013

In the modern fashion industry, efficiency has been increasing thanks to development of computer graphics, IT technology, and digitalization. Unlike the past when fashion design heavily depended on handwork, digitalization of fashion industry makes fabrication time shorter and enables designers to adopt comprehensive expression, generating high value-added product. The Apparel CAD, an example of the digitalized fashion industry, has been developed from 2D system into a system providing 3D simulation. Digital clothing can be determined as an activity of designers using the tool in order to fabricate pattern and simulate its designed clothes in the virtual space of computer. In this study, physical properties of eight materials, which can be utilized on a par with current fashion trend, have been specified. For more sophisticated investigation, external appearance of the material was investigated by 3D scanning. In order to examine the physical properties of fabric specimens, KES(Kawabata Evaluation System) measurements and other physical property measurements were made. With the results, virtual material and clothes were simulated via CLO 3D, one of 3D apparel CAD systems. Then, virtual fabrics and clothes of similar types were generated and analyzed.