• Explosives and Blasting
• /
• v.16 no.3
• /
• pp.16-24
• /
• 1998

Methods of Rock fragmentation are used rock of housing repair development at KU-SAN DONG area in seoul Youn-Pyong Ku. So, Theorical analyses of the effect of vibration and frequency on structural damage around old housed also discussed. The results can be summarized as follows: 1. A area(Rock area not more than 15m Ku-San Mention) Some Empirical equations were obtained $V=K\{{\frac{D}{W}}1/3\}^{-n}$ where the values for n and K are estimated to be -1.64 and 94 respectively, this values were obtained only theorical analyses. If we have 125g charge this area is impossible blasting operation, so this area must be worked by SRS(Super Rock Splitter) method. 2. B area(Rock area from 15m to 25m in a boundary line from Ku-San Mention) This area charge is about 125g in a delay time by some empirical equation s. So, this area can be blasting operations by small charge. 3. C area(Rock area from 25m to 35m in a boundary line from Ku-San Mention) This area charge is about 500g in delay time by some empirical equation s. So, this area can be blasting operations by middle charge. 4. D area(Rock area more then 35m in a boundary line from Ku-San Mention) This area charge is about 1000g in a delay time by some empirical equation s. So, this area can be blasting operations by middle charge.

• Communications for Statistical Applications and Methods
• /
• v.11 no.3
• /
• pp.513-518
• /
• 2004

The well-known mode-mean-median inequality for the unimodal population distribution does not always hold for the frequency distribution. But many elementary statistics text books just mention that the relative location of the mean and median can be used to determine whether a distribution is positively or negatively skewed. In this paper we introduce the method generating data that is positively skewed but mean

• Journal of Electrical Engineering and Technology
• /
• v.3 no.3
• /
• pp.422-429
• /
• 2008

This paper presents compact low frequency ultra-wide band (UWB) sensor design and study of the partial discharge diagnosis by sensing electromagnetic pulse emitted from the partial discharge source with the newly designed UWB sensor. In this study, we designed a new type of compact low frequency UWB sensor based on microstrip antenna technology to detect both the low frequency and high frequency band of the partial discharge signal. Experiments of offline PD testing on medium voltage (22.9kV) underground cable mention the comparative results with the traditional HFCT as a reference sensor in the laboratory. In the series of comparative tests, the calibration signal injection test provided with the conventional IEC 60270 method and high voltage injection testing are included.

• Journal of Electrical Engineering and Technology
• /
• v.3 no.2
• /
• pp.263-270
• /
• 2008

We studied partial discharge detection by sensing electromagnetic waves emitted from the partial discharge source in an HV Rotating Machine using a UWB sensor. In this study, we design a new type of compact low frequency UWB sensor based on micro-strip technology. We also perform many experiments of offline and dismantled testing compared with the existing HFCT on stator winding of the HV generator. We mention the detailed design of a new compact UWB sensor along with the time domain PRPD pattern and frequency domain results of partial discharge in the stator winding of a 6.6kV rotating machine by offline testing performed in a laboratory.

• International journal of advanced smart convergence
• /
• v.10 no.4
• /
• pp.134-140
• /
• 2021

Big data has recently been used in various industries such as tourism, medical care, distribution, and marketing. And it is evolving to the stage of collecting real-time information or analyzing correlations and predicting the future. In the tourism industry, big data can be used to identify the size and shape of the tourism market, and by building and utilizing a large-capacity database, it is possible to establish an efficient marketing strategy and provide customized tourism services for tourists. This paper has begun with anticipation of the effects that would occur when big data is actively used in the tourism field. Because the method of use must have applicability and practicality, the spatial scope will be limited to Seosan, Chungcheongnam-do, and research will be conducted. In this paper, to improve the quality of tourism courses by collecting and analyzing the number of mention data and sentiment index data on social media, which reflect the tourist's interest, preference and satisfaction. Therefore, it is used as basic data necessary for the development of new local tourism courses in the future. In addition, the development of tourism courses will be able to promote tourism growth and also revitalizing the local economy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.267-268
• /
• 2008

This paper presents compact low frequency ultra-wide band(UWB) sensor design and studying of the partial discharge diagnosis by sensing electromagnetic pulse emitted from the partial discharge source with new designed UWB sensor. In this study, we designed new type of compact low frequency UWB sensor based on microstrip antenna technology to detect both low frequency and high frequency band of partial discharge signal. And experiments of offline PD testing on in medium voltage (22.9kV) underground cable and mention the comparative results with the traditional HFCT as a reference sensor in the laboratory. In the series of comparative test, the calibration signal injection test provided with conventional IEC 60270 method and high voltage injection testing are included.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.11
• /
• pp.1254-1261
• /
• 2007

Mc-OFDM(Multi code-Orthogonal Frequency Division Multiplexing) modulation has been developed for high-speed data transmission over wireless channels. However, this system suffers critical problem from relatively high PAPR(Peak to Average Power Ratio). To reduce PAPR, we suggest a new technique, called Mapping using (N+1)PSK and demonstrate the performance of mapped Mc-OFDM system. On the other side, in OFDM system, each sub-carrier experiences different fading, thus some sub-carriers may be completely lost because of deep fade. To solve a above mention problem, we propose cooperative communications that improve the reliability of sub-carriers through spatial diversity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.92-97
• /
• 2002

There are a lot of roots of errors in an motion of the optical pick-up actuator being one of the most significant components in a CD-ROM drive. Most of the studies recently performed have a tendency to seek for the causes from an actuator itself. This paper present the dynamic characteristics of an actuator affected by the motion of a feeding deck. The feeding system is modeled as a rigid body with eight degree-of-freedom. Using Largrange's equation, we derive the linear equations of motion with respect to the rectangular coordinate. We found the fact that the ranges of the natural frequencies of a feeding deck and an actuator are close to each other. And the time responses are also computed by the Newmark method and Runge-Kutta method.

• Journal of Distribution Science
• /
• v.13 no.2
• /
• pp.45-53
• /
• 2015

Purpose - This study strives to discern trends in research productivity in the Journal of Consumer Behavior. It will identify prolific authors and institutions in articles over ten years (2004-2013). Research design, data, and methodology - The Journal of Consumer Behavior was chosen and articles over ten years were analyzed. Research productivity was determined by categorizing the data into four themes: number of authors per article, author affiliated institutions, a list of prolific authors over a ten-year period, and author-affiliated countries. Results - Authors have a propensity to collaborate on a research paper, yielding a high frequency of articles with two or three authors in a single publication. In addition, author and institution productivity was highest in North America and Europe. Conclusions - The research productivity of the Journal of Consumer Behavior is unprecedented. The trends and insights from this study will allow academics in the area of consumer behavior to observe leading authors and institutions. Moreover, speculations about the leading countries and institutions, not to mention top prolific authors in consumer behavior, will be elucidated in this study.

• Journal of Arbitration Studies
• /
• v.24 no.1
• /
• pp.59-83
• /
• 2014

In the past, the mention of "international arbitration" would have brought to mind only commercial arbitration. However, the frequency of investment treaty arbitration has seen remarkable grow thanks to the rise of globalization and the spread of multi-national corporations. Reflecting on the current state of the world, this paper introduces the meaning, characteristics, and differences between commercial arbitration and investment treaty arbitration in the context of procedural considerations. To this end, this paper examines some major procedural differences among the said types of arbitration, by dividing commercial arbitration into institutional arbitration and ad hoc arbitration, and dividing investment treaty arbitration into ICSID arbitration and UNCITRAL Rules arbitration.