• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.5
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• pp.369-377
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• 1999

Recently, it is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research. considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness. Accordingly, for the detection of delamination between the junction condition of boundary microdefect of thin film sandwiched between three substances the results from digital image processing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.351-363
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• 2006

The 8-VSB modulation, the transmission standard for the terrestrial digital television(DTV) of the Advanced Television Systems Committee(ATSC), suffers from multipath fading because it conveys information on the amplitude. To solve this problem, decision feedback equalizers(DFE's) have been commonly used in terrestrial DTV receivers. However, under severe channels, such as a 0 dB ghost channel or a single frequency network (SFN) channel, the DFE shows unstable convergence due to the error propagation caused by decision errors. Instead of unstable time-domain DFE schemes, by proposing a frequency-domain direct-inversion equalization method, we try to guarantee stable equalization and achieve low symbol error rates. To secure the existence of a channel inverse, channel-matched filtering and noncausal filtering are carried out prior to equalization. Simulation results show that the proposed method performs much better than existing DFE schemes in terms of both the stability and the symbol error rate.

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.163-171
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• 2017

Brick is not only aesthetically beautiful and emotional material, but also eco-friendly and good building commodity for human health. Nonetheless, the use of brick has declined, due to the difficulty of building high-rise buildings and the limitation of the free form implementation. However, modern society is increasingly interested in environmentally friendly finishing materials for solving environmental problems. From this point of view, the brick architecture is being reexamined as a material to improve the living environment and to provide comfort without destroying nature. In addition, the development of digital technology enables the implementation of various types of masonry method and curved forms. Parametric design is one of the ways to realize the curved forms and various architectural expressions for brick architecture. In this background, the purpose of this study is to develop algorithms that can easily generate curved brick walls through parametric design, enable various pattern designs, and respond to real-time feedback. The details of the study are as follows. First of all, we examine organic architecture, the trend of brick architecture, and the concept of parametric design. Secondly, In order to generate curved surface with complex curvature, major planning factors affecting form generation are examined. Finally, we develop a parametric design method that consists of generating a curved surface for brick arrangement, implementing a parametric algorithm, and generating a curved form using bricks. Consequentially, we propose an algorithm that can maximize the use of ready-made bricks without using cut bricks to design curved walls and present efficient and economical design alternatives.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.97-100
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• 2009

The surface parameters associated with the land are usually dependent on the climate, and many physical processes that are displayed in the image sensed from the land then exhibit temporal variation with seasonal periodicity. An adaptive feedback system proposed in this study reconstructs a sequence of images remotely sensed from the land surface having the physical processes with seasonal periodicity. The harmonic model is used to track seasonal variation through time, and a Gibbs random field (GRF) is used to represent the spatial dependency of digital image processes. In this study, the Normalized Difference Vegetation Index (NDVI) was computed for one week composites of the Advanced Very High Resolution Radiometer (AVHRR) imagery over the Korean peninsula for 1996 and 2000 using a dynamic technique, and the adaptive reconstruction of harmonic model was then applied to the NDVI time series for tracking changes on the ground surface. The results show that the adaptive approach is potentially very effective for continuously monitoring changes on near-real time.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.503-510
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• 2001

In this paper. we describe a 32-channel bioimpedance measurement system It consists of 32 independent constant current sources of 50 kHz sinusoid. The amplitude of each current source can be adjusted using a 12-bit MDAC. After we applied a pattern of injection currents through 32 current injection electrodes. we measured induced boundary voltages using a variable-gain narrow-band instrumentation amplifier. a Phase-sensitive demodulator. and a 12-bit ADC. The system is interfaced to a PC for the control and data acquisition. We used the system to detect anomalies with different resistivity values in a saline Phantom with 290mm diameter The accuracy of the developed system was estimated as 2.42% and we found that anomalies larger than 8mm in diameter can be detected. We Plan to improve the accuracy by using a digital oscillator improved current sources by feedback control, Phase-sensitive A/D conversion. etc. to detect anomalies smaller than 1mm in diameter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.315-318
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• 2005

Recently, the advent of wireless communication and other handhold devices like Personal Digital Assistants and smart cards have made in implementation of cryptosystems a major issue. One important aspect of modern day ciphers is the scope for hardware sharing between the encryption and decryption algorithm. The cellular Automata which have been proposed as an alternative to linear feedback shift registers(LFSRs) can be programmed to perform the operations without using any dedicated hardware. But to generalize and analyze CA is not easy. In this paper, we characterizes uniform/hybird complemented group CA with rules 195/153/51 that divide the entire state space into smaller spaces of maximal equal lengths. This properties can be useful in constructing key agreement algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.162-169
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• 2011

The flight control system utilize RSS(Relaxed Static Stability) criteria in both longitudinal axes to achieve performance enhancements and improve stability. The aircraft using digital flight-by-wire flight control system receives aircraft flight conditions such as pitch, roll and yaw rate, normal acceleration from RSA(Rate Sensor Assembly) and ASA(Acceleration Sensor Assembly). These sensors has permissible measurement error related to system safety of an aircraft but, unexpected flight motions are happened by sensing errors such as offset, noise and etc. The unexpected pitch down tendency occurred by ASA sensor bias in 1g level flight with pilot hands-off. This paper addresses the design and verification of flight control law to improve of pitch down or up tendency caused by ASA sensor bias. The result of analysis and flight test reveals that pitch down tendency can be improved by pitch attitude feedback system.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.159-171
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• 2009

The objective of this research is to explore a method to utilize a programmable robot, as a potential learning tool in the elementary school's curricula. Due to their programmability and operational ease of use, programmable robots are among digital toys that today offer specially instructive features. In this research, we developed the robot game-based project contents as a tool for teaching the elementary school children to learn the algorithm, the essential part of computer programming. The LEGO material, selected as the construction kit for robot, consists of a mechanical assembly system, a set of sensors and actuators, a central control unit, a programming environment. The project requires the children to complete 3 separate tasks, each of which is developed based on the principles of algorithm. The classroom feedback supports that the robotic experiences provided the children with fun and absorption. It is likely that implementing learning with robot in regular classroom in elementary school can bring new possibilities to the educational system, provided that a thorough preparation backs up the plan.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.219-227
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• 2015

This study was designed to investigate dietary life related to sodium of participants in hypertension and diabetes preventive education at the public health center located in Incheon Metropolitan City. Subjects were comprised of 301 adults (males: 102, female: 199) of age 50 years and above. The questionnaire for dietary life and salty taste assessment were performed on the subjects. Data were analyzed using SPSS package (ver. 18.0). According to the result of questionnaire for dietary behavior, 70% of the subjects were in the low salt intake group (p<0.001). In the result of questionnaire for dietary frequency, all ages groups were in the low salt intake group (p<0.01). The data of questionnaire for dietary behavior showed that the subjects of age above 75 years preferred salted seafood, soup, and kimchi (p<0.01). The data of questionnaire for dietary frequency showed that the subjects of age between 65 and 74, least chose fried kimchi, noodle, and soybean paste soup with clams (p<0.05), and the healthy adult groups chose kimchi stew, ssam and ssamjang (p<0.05). The score for dietary behavior in male subjects was higher than female subjects (p<0.01). In particular, the score for dietary frequency was the lowest in the subjects of age between 65 and 74 (p<0.01). The mean value of salty taste assessment in the subjects was 0.41% which is higher than the ideal value of 0.3% (p<0.01). Offering more nutrition education and continuous feedback of healthcare center may be needed to improve the health status of the adults.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.8-15
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• 2021

This study was conducted with the purpose of exploring the dilemma and improvement strategies for the integrated management of extracurricular education programs at Duksung Women's University. The research method was finally composed of a procedure with a meeting of experts based on the procedure of collecting and analyzing the previous research literature. As for the contents of the study, the dilemma of the integrated management of the extracurricular education program at Duksung Women's University was presented first. Examples of dilemmas include difficulties in organizing and operating programs from the perspective of a roadmap customized for each grade level, difficulties in establishing a foundation for balanced mapping of core competencies and cultivating programs, difficulties in managing the performance of regular program monitoring and feedback improvement, and activating the linkage system between subjects and extracurricular education programs difficulties and difficulties in establishing a support system for the operation of the extracurricular education integrated management system were reflected. In addition, a strategy to complement and improve this dilemma was presented in a linkage. As a result of the study, the integrated management dilemma of Duksung Women's University's extracurricular education programs needs to be resolved in the long term through formal infrastructure such as external expert advice and expert exchange, and the development and use of related manuals should be considered aspects were analyzed. In addition, the content of this study was analyzed not only in the educational case of Duksung Women's University, but also in that it deals with cases that can be usefully referenced in most universities that develop and operate extracurricular education programs. Finally, this study presents an evidence-based practices that can be referenced in promoting the integrated management of extracurricular education programs in university sites, and the position and identity of extracurricular education throughout the university curriculum. It is judged that the significance and expected effect of the study can be obtained in that it provides an opportunity to improve from the management point of view.