• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.63-68
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• 2014

This paper proposed a novel compressed sensing (CS) technique for an efficient video transmission of multi-copter. The proposed scheme is focused on reduction of the amount of data based on CS technology. First, we describe basic principle of Spectrum sensing. And then we compare AMP(Approximate Message Passing) with CoSaMP(Compressive Sampling Matched Pursuit) through mathematical analysis and simulation results. They are evaluated in terms of calculation time and complexity, then the promising algorithm is suggestd for multicopter operation. The result of experiment in this paper shows that AMP algorithm is more efficient than CoSaMP algorithm when it comes to calculation time and image error probability.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1147-1167
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• 2015

Wireless smart sensors, which have become popular for monitoring applications, are an attractive option for implementing structural control systems, due to their onboard sensing, processing, and communication capabilities. However, wireless smart sensors pose inherent challenges for control, including delays from communication, acquisition hardware, and processing time. Previous research in wireless control, which focused on semi-active systems, has found that sampling rate along with time delays can significantly impact control performance. However, because semi-active systems are guaranteed stable, these issues are typically neglected in the control design. This work achieves active control with smart sensors in an experimental setting. Because active systems are not inherently stable, all the elements of the control loop must be addressed, including data acquisition hardware, processing performance, and control design at slow sampling rates. The sensing hardware is shown to have a significant impact on the control design and performance. Ultimately, the smart sensor active control system achieves comparable performance to the traditional tethered system.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.345-346
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• 2009

This research focused on large variation of the result of Ca(OH)$_2$ quantity by TG/DTA test or micro-pore size by MIP test. Assume that sample postion has influenced on experimental result, therefore, relationship between sampling position and the experimental result was studied As a result of the research, it is obvious that samples from inside(P-3) shows more Ca(OH)$_2$ and less porosity than samples from outside(P-1).

• Journal of Korean Society for Quality Management
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• v.36 no.1
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• pp.7-19
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• 2008

During the past two decades, a huge amount of research on adaptive control charts has been accomplished. Especially, variable sampling interval (VSI), variable sample size (VSS), and variable sample size and sampling interval (VSSI) charts have been focused by many researchers due to their simplicity and efficiency. On the other hand, the difference among notations, assumptions, methodologies may cause confusions in per forming further studies or practical implementations. This research analyses and compares diverse models so as to provide a unified view on statistical and economical characteristics. As a result, we perform comparative study on economical design models of VSI, VSS, and VSSI charts, respectively, We also present practical guidelines to utilize those adaptive control charts.

• Journal of Power System Engineering
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• v.17 no.4
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• pp.139-146
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• 2013

Because the magnetic bearing supports levitating body without contact, wear, noise and vibration, it is very useful to high revolution machinery. In this paper we selected ATmega 128, a less expensive and widely used micro controller, for control the magnetic bearing system. And we selected the sampling time and the control gain of PID controller through trial-and-error. The control program of the one board controller utilized lookup table to reduce calculation time, and bit shifting for the integer calculation in instead of floating point calculation. As the results, the controller carried out relatively high speed PID control on sampling time 0.25 ms. At last the rotation test for the magnetic bearing system was carried out by 3 phase induction motor and air turbine.

• Journal of the Korean Home Economics Association
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• v.33 no.5
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• pp.115-127
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• 1995

The purpose of this research was to investigate the economic status and problems of the middle aged apartment-residents in Seoul as a part of collaborative study on family issues of them. The sampling households were divided into Kangnam and Kangbuk area according to their residential location and upper-middle and lower-middle groups according the size of the apartment unit. The analysis of this research was specially focused on the latter division. The data were collected from 307 fulltime housewives with at least one child in a middle or high school. This data were gathered from the structured questionnaire. The major findings of this research were as follows: 1. The significant differences between upper-middle and lower-middle groups were showed in such areas as household income, monthly living expenses, household assets and savings. 2. The most serious economic problem was the private education expenses in both groups. 3. The economic satisfaction of the group in the Kangbuk area was a little higher than the group in Kangnam area.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.5
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• pp.107-116
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• 1992

Recently, it is gradually raised necessity that interface is measured accurately and managed in industrial circle and medical world. An Ultrasonic wave transmitted from a focused beam tranducer is being expected as a powerful tool for NDE of the delamination. The Ultrasonic NDE of the delamination is based on the form of the wave reflected from the interface. In this study results, automatically repeated discrimination analysis method can be devided in the category of all kinds of defects on semiconductor package, and also can be possible to have a sampling of partial delamination.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.49-59
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• 2004

The concectration and distribution of contaminants obtained from a contaminated land investigation or an environmental geochemistry survey constitutes the basis of a decision-making process on environmental policies or of scientific researches. As the quality of data determines the reliability of the result, the investigation plan should be adjusted according to the purpose of the investigation. In general, the effort to improve the data quality had been focused mainly on the QA/QC procedures in laboratories. The rapid progress of analytical instrument has also contributed toward improving the analytical precision to a sacrificable degree. Nevertheless, in many cases, it is not the analytical precision that needs improvement for the better precision of overall measurement process: it is rather during the sampling process in the field that is responsible for the poor precision. To assess the data quality on a measured value, ISO recommends to provide information on "measurement uncertainty" along with the measured value. The measurement uncertainty in an environmental measurement context can be explained as the statistical number that expresses the degree of the uncertainty stemming from the sampling and analytical procedures. There is a cost involved in order to improve the precision of sampling and analytical methods so as to decrease the degree of measurement uncertainty. The economical point of compromise in an investigation planning can be achieved when the allowable degree of uncertainty has been set before-hand. The investigation can then be planned accordingly not to exceed the uncertainty limit. Furthermore, if the measurement uncertainty estimated from the preliminary investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the investigation should be allotted cost-effectively to reinforce the weakest link of the whole investigation process. This paper aims to present a method of estimating the level of measurement uncertainty of a measured contamination concentration at a site used as an example and to show how the estimated uncertainty can be applied to serve the particular purpose of an investigation.

• Korean journal of food and cookery science
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• v.15 no.4
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• pp.327-337
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• 1999

This study was conducted on a sampling of 700 mixed college students from seven different schools nationwide by written questionnaire to evaluate the value system of convenience foods among Korean college students. Korean students put value on the following categories of convenience foods in order; convenience, taste, price, appearance, appliance to daily life, variety, locality, nutritional value, originality, improvement required, cleanliness and tradition. Significant differences between the sexes occurred in categories as cleanliness and convenience, since females considered convenience foods as convenient but not so clean (safe to eat). This study also conducted factor analysis on 24 individual convenient foods. Noodles laid emphasis on nutritional value; where refrigerated foods, ready to eat (RE) side dishes, on-the-spot kimbab, and sandwiches focused on cleanliness. Noodles. cereal, and instant soup focused on price. Frozen pizza, noodles, retort, RE meat, ham, fish cakes were dependent on locality and traditionality. Noodles, instant food, and packed kimchi scored highly on convenience. Frozen fried rice, retort, instant porridge, instant rice, RE meat, cereal, instant soup, and RE side dishes on consumption on a regular basis. Cereal, refrigerated foods, and RE side dishes laid emphasis on taste. Noodles, instant rice, cereal, ham, and RE side dishes focused on variety. Retort, RE meat, ramen, cereal, ham, and on the spot sandwiches looked to originality, while canned foods was recognized as ‘needing improvement’.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.205-218
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• 2019

Music sampling, which has been popular since hip-hop DJs used it in the 1970s, is now one of methods of producing music that is used regardless of genre or country. In this study, an overall production methodology for music sampling was presented through in terms of content and techniques. First of all, in terms of the contents, we classified them into the reuse and length of materials, and the function of samples in the mixed songs. In terms of the techniques, editing and effecting techniques were classified. By combining these elements, the methodology of music sampling applicable to the productions as well as the analysis was presented. Based on this methodology, the sampled songs of Korean Popular musicians - Jang Ki-ha and Faces, Epik High, The Quiet, and DJ DOC - were successfully analysed. Through the analysis process, the organic relationship of elements within the methodology was investigated, and the results of the analysis showed the effectiveness of the proposed methodology. This study can be meaningful in laying the groundwork for applying music sampling directly when actually producing songs or analyzing sampled songs.