• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.189-196
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• 2002

As the quantity of transported goods increases, there is a lot of mechanical trouble with loading facilities. So it tremendously produces not only economic loss but also time loss. To reduce the loss from the trouble of leading facilities, it is necessary to analyse the distribution of the problem's occurrence and use the analyzed data to minimize the outbreak of trouble. So the data can be usefully used when designing or manufacturing and it also can be utilized for proper maintenance of operating equipment, frequency of inspection and repair, know-how of checking on equipment and purchasing of spare parts. And it is possible to minimize the loss if the propel maintenance is adapted

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.57-58
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• 2005

The properties such as capacitance and resonant frequency are important in embedded capacitors. Accurate equivalent model is required to find these properties of embedded capacitor. In this paper, we investigate to analyze the properties of high-K embedded capacitor which was fabricated by Low Temperature Co-fired Ceramic (LTCC). Modeling based on partial element equivalent circuit (PEEC) method is performed using HSPICE circuit simulation. This modeling methodology can provide the good inspection of embedded capacitor to device engineer.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.942-944
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• 2005

In this study, eddy current signals from various anomalous defects in the heat exchanger tube are predicted af their signal slope characteristics no analyzed. The signal changes due to frequency increase are also observed. Based in the accumulated knowledge, the analysis of superimposed signal is attempted which includes the effects of support plate. Both differential and absolute bobbin probe signals are analyzed. For the prediction of signals, axisymmetric finite element modeling is used and this leads us to the utilization of slope angle analysis of the signal. Results show that differential signals are useful to locate the position of defect under the support plate and absolute signals no easy to predict and analyze even though they no superimposed signals. Combined use of these two types of signals will accomplish a reliable inspection.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.377-385
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• 1996

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. the former is accurate but requires a great deal of time and efforts while the latter lacks reliability. this paper proposes a new method to solve this problem at a time. the permissible vibration level to a precision equipment can be easily obtained by analyzing a process of Frequency Response Function. This paper also demonstrates its effectiveness by applying the proposed method to finding the vibration criteria of a Computer Hard Disk Drive by impact Test.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1506-1508
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• 2015

A 2D barcode region localization system for the automatic inspection of a long distance logistics objects has been developed. For the successful 2D barcode localization, variance and frequency of the pixel distribution within average 2D barcodes is modeled and the average model of 2D barcode is combined with the corner features detection to localize the final 2D barcode candidates. An automatic 2D barcode localization software was developed with the multiple features mixture method and we tested our system on real camera images of several popular 2D barcode symbologies.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.114-119
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• 2022

The analysis conditions were established using the self-weight of the FCT automation equipment, and natural frequency analysis was performed under the same conditions. For the structural analysis, 3D modeling was performed using Inventor, and structural analysis was performed using the Ansys workbench. From the structural analysis, it was concluded that the resulting values of the stress and deformation of the equipment do not affect the equipment. From the dynamic analysis, the resonance does not occur in the equipment driving area, and thus it is judged to be stable.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.822-829
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• 2022

According to existing study into the remote fault diagnosis procedure, the current diagnostic approach has an imperfect decision model, which only supports communication in a close distance. An Internet of Things (IoT)-based remote fault diagnostic approach for wind power equipment is created to address this issue and expand the communication distance of fault diagnosis. Specifically, a decision model for active power coordination is built with the mechanical energy storage of power generation equipment with a remote diagnosis mode set by decision tree algorithms. These models help calculate the failure frequency of bearings in power generation equipment, summarize the characteristics of failure types and detect the operation status of wind power equipment through IoT. In addition, they can also generate the point inspection data and evaluate the equipment status. The findings demonstrate that the average communication distances of the designed remote diagnosis method and the other two remote diagnosis methods are 587.46 m, 435.61 m, and 454.32 m, respectively, indicating its application value.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.167-174
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• 2001

Reflection method using ultrasonic source has been attempted to obtain the information about tunnel lining structures composed of lining, shotcrete, water barrier and voids at the back of lining. In this work, two different types of sources, i.e. single-pulse source and sweep source, can be used. Single-pulse source with short time duration has the frequency content whose amplitudes tend to be concentrated around the dominant frequency, whereas sweep source with long time duration denotes a flat distribution of relatively larger amplitude over a broad frequency band, although the peak to peak amplitude of single-pulse source wavelet is equivalent to that of sweep source one. In traditional seismic application, a single-pulse source(weight drop, dynamite) is typically used. However, to investigate the fine structure, as it is the case in the tunnel lining structure, the sweep wavelet can be also a desirable source waveform primarily due to the higher energy over a broad frequency band. For the investigation purposes of sweep source, a physical modeling is a useful tool, especially to study problems of wave propagation in the fine layered media. The main purpose of this work was using a physical modeling technique to explore the applicability of sweep source to the delineation of inner layer boundaries. To this end, a two-dimensional physical model analogous to the lining structure was built and a special ultrasonic sweep source was devised. The measurements were carried out in the sweep frequency range 10 ∼ 60 KHz, as peformed in the regular reflection survey(e.g. roll-along technique). The measured data were further rearranged with a proper software (cross-correlation). The resulting seismograms(raw data) showed quitely similar features to those from a single-pulse source, in which high frequency content of reflection events could be considerably emphasized, as expected. The data were further processed by using a regular data processing system "FOCUS" and the results(stack section) were well associated with the known model structure. In this context, it is worthy to note that in view of measuring condition the sweep source would be applied to benefit the penetration of high frequency energy into the media and to enhance the resolution of reflection events.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.379-388
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• 2020

The contents and scope of this study are to analyze the problems of the current radio service and radio station classification system, and to investigate the radio wave management cases in the United States to provide a reasonable and efficient radio wave management method. The results of this study can be used as basic data when revising the legal system regarding radio wave enforcement regulations, radio service and radio station classification standards. It is expected that in the future, a detailed commentary on the definition and classification system of new radio / radio stations will be prepared to increase policy compliance in practice, while contributing to enhancing the consistency and efficiency of radio station licensing and inspection.

• Journal of the Korean Society of Costume
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• v.50 no.4
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• pp.103-115
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• 2000

The purpose of this study is to provide consumers with practical information for reasonable purchasing by analyzing apparel purchasing behavior. information source use, demographic differences in terms of life style patterns, moreover, to support apparel manufacturers in producing goods and making a plan by developing more effective advertisements and efficient marketing strategy, such as media strategy. This study targeted 832 men and women wearing sports casual wear. Information source is used to analyze the data and MANOVA, ANOVA. Scheffe is employed for post-inspection and demographic bases are based on the frequency of each type. The followings are the conclusions of this study : 1. In case of print media, TV, PC factor, fashion advocates and individuality advocates most frequently used information source. In case of purchasing experience factor, individuality advocates skewed higher frequency than conformity type. and then, in case of observation information use factor, individuality advocates were ranked as the highest and conformity type as the lowest. In case of human information use factor, fashion advocates and individuality advocates showed higher frequency than practical type and conformity type. 2 In case of female, Individuality advocates was ranked as the highest. In case of male, practical type and conformity type were rank as the highest. Fashion advocates ranked as the lowest in any case. 3. Individuality advocates were ranked as the highest among people aged 14 to 16, practical type among 17 to 19, conformity type among 20 to 23, conformity type among over 20. 4. Middle school students tended to be the individuality advocates, high school students the practical type, university students the practical type and the conformity type, and company workers conformity type.