• Journal of the Korean Society of Industry Convergence
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• v.14 no.4
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• pp.151-156
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• 2011

The domestic mine development community the countermeasure establishment is insufficient about ground sinkage, not only the mine which is a in line is partial from the mine of the most which has become the rest mine and abandoned mine or the index sinkage occurs. The ground sinkage which occurs from the abandoned mine area most after operation is stopped, a long time passes and accurately predicts an occurrence location and a time with the residual sinkage which occurs, is difficult. Underground goaf of the abandoned mine and the closed shaft When considering the potentiality which causes the instability of ground, is a possibility of reaching a damage in the ground infrastructure or life. The underground shaft which is formed specially with mine development and goaf operates with the obstacle factor in the development project of the mine area, the ground sinkage which is caused by with sinkage, operates with the large safety accident occurrence factor where the important infrastructure of the railroad, road, residential area etc. is damaged. Therefore, In this paper, the goaf cave of the abandoned mine area, for the displacement behavior according to the filling factor of the material is to analyze the numerical analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.713-717
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• 2014

This paper presents a beamforming technique for locating impulsive sound source. The conventional frequency-domain beamformer is advantageous for localizing noise sources for a certain frequency band of concern, but the existence of many frequency components in the wide-band spectrum of impulsive noise makes the beamforming image less clear. In contrast to a frequency-domain beamformer, it has been reported that a time-domain beamformer can be better suited for transient signals. Although both frequency- and time-domain beamformers produce the same result for the beamforming power, which is defined as the RMS value of its output, we can use alternative directional estimators such as the peak value and crest factor to enhance the performance of a time-domain beamformer. In this study, the performance of three different directional estimators, the peak, crest factor and RMS output values, are investigated and compared with the incoherent interfering noise embedded in multiple microphone signals. The proposed formula is verified via experiments in an anechoic chamber using a uniformly spaced linear array. The results show that the peak estimation of beamformer output determines the location with better spatial resolution and a lower side lobe level than crest factor and RMS estimation in noise free condition, but it is possible to accurately estimate the direction of the impulsive sound source using crest factor estimation in noisy environment with stationary interfering noise.

• Earthquakes and Structures
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• v.7 no.5
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• pp.891-906
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• 2014

The purpose of this study is to propose a modification factor to reflect the lateral stiffness modification when a step is located in flat plates. Reinforced concrete slabs with steps have different structural characteristics that are demonstrated by a series of structural experiment and nonlinear analyses. The corner at the step is weak and flexible, and the associated rotational stiffness degradation at the corner of the step is identified through analyses of 6 types of models using a nonlinear finite element program. Then a systematic analysis of stiffness changes is performed using a linear finite element procedure along with rotational springs. The lateral stiffness of reinforced concrete flat plates with steps is mainly affected by the step length, location, thickness and height. Therefore, a single modification factor for each of these variables is obtained, while other variables are constrained. When multiple variables are considered, each single modification factor is multiplied by the other. Such a method is verified by a comparative analysis. Finally, a complex modification factor can be applied to the existing effective slab width.

• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.41-60
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• 2019

This study aims to identify factors that pharmaceutical logistics companies must consider when selecting a logistics center; it also aims to analyze the importance-satisfaction-of these factors by using IPA. The main results are as follows. First, overall, the aforementioned factors are divided into logistics factor, economic factor, environmental factor, and policy factor, and most of the specific attributes of each main factor are less satisfied than the importance. Second, the users of pharmaceutical logistics are divided into producers, distributors, clinics, and pharmacies. The analysis of each user shows a need to improve logistics factors as well as an overinvestment in environmental factors. The results can provide drug distribution companies directions for selecting logistics centers as well as strategic implications.

• The Korean Journal of Community Living Science
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• v.19 no.4
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• pp.537-546
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• 2008

The purposes of the study was to identify customers' satisfaction factors regarding foods and services in food courts in big department stores and discount stores in Seoul and Cheonan. A survey of 235 customers was conducted regarding customer satisfaction levels and factors of food and services. Customers' perceived level of attributes were identified into eight underlying dimensions by factor analysis as follows: factor 1 was "cleanliness": factor 2 "service quality": factor 3 "accuracy": factor 4 "atomosphere": factor 5 "food quality": factor 6 "menu information": factor 7 "price" and the eighth factor was "food result". Regression analysis indicated that "cleanliness" was found to be the most important factor contributing to customers' overall satisfaction. There were significant differences in customers' perceived satisfaction level of "food quality"(p<0.01), "accuracy", and "price" factors(p<0.05) between department stores and discount store. The customers' perceived satisfaction levels of "accuracy", "food quality" and "price" factor at a large store food court are higher than those of department store food court. Comparing location of food court, there were significant differences in customers' perceived satisfaction level of "accuracy" and "price" factors between in Seoul and Cheonan(p<0.001). The customers' perceived satisfaction levels of "accuracy" and "price" at the discount store in Seoul are lower than those of food court at Cheonan. It is suggested that the management should pay attention to the sanitation of their dinning halls, kitchens, hygienic dishes, hygienic water fountain, employee hygiene, and a proper place to put used dishes to increase the customers' satisfaction.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.15-20
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• 2020

In this paper, delay diffusion for exhibition hall and conference room was measured and analyzed in the indoor environment of the building. Scenarios for the indoor environment of the two buildings were written. also, the system configuration and measurement methods were conducted under the same conditions. The measurement conditions were set to 3 GHz and 6 GHz of center frequencies and analysis band selected 2 GHz. The measurement system consisted of vector network analyzer, power amplifier, omni-directional transmit and receive antenna, and transmission line. According to the indoor environment scenario of the two buildings, the location of the receiving antenna was divided into three zones based on the location of the transmitting antenna and this was measured at 1 m intervals according to 18 locations. The power delay profiles, RMS delay spread, and K-factor results of two buildings were compared and analyzed.

• Journal of Families and Better Life
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• v.9 no.2
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• pp.225-240
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• 1991

The purpose of this study is to find the main factor which influences the housing satisfaction of elderly who lives alone or with spouse and to make it sure that housing satisfaction is an important factor to life satisfaction of elderly. The specific purpose of this study is as follows; 1) How does the locus of control of elderly influence a housing satisfaction\ulcorner 2) How does the housing characteristics of elderly influence on the housing satisfaction and this relationship has any difference between urban and rural area. 3) Which variables influence upon the housing satisfaction and life satisfaction of elderly and how much do they influence \ulcorner The locus of control scale, housing satisfaction scale. life satisfaction scale were composed on the basis of precedent researches. For this study 202 elderly sho live in urban and rural area ere interviewed. To analyze the data, such as F-test, t-test, two-way ANOVA, Multiple regression analysis were used with SPSS program. The results are as follows; 1) The interrelation between locus of control and housing satisfaction is as follows. Namely , if he believes in his deeds and will rater than his fate, he feels more housing satisfaction. 2)the housing satisfaction of the elderly was found to be influenced by location, Namely, the elderly living in the urban area feels more housing satisfaction, especially he lives in apartment and unshared house. On the contrary, the elderly living in the rural area was not affected by housing type and the number of household who live together, The housing satisfaction of the elderly living in the rural area or the urban area equally influenced by the housing tenure, heating system, bathroom facility, flush toilet, and convenient service form the outside. 3) The main factoers which influence the housing satisfaction of the single household elderly are bathroom facility louse of control and income. When we concern about the location in urban area the housing satisfaction of the elderly were mainly influenced by income, but in the rural area, they were influenced by the service facility from the outside. As a Conclusion, the main factor which influenced life satisfaction of the elderly proved to be housing satisfaction inn both rural and urban area.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.499-506
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• 2002

The purpose of this study is to develop landslide susceptibility analysis techniques using artificial neural networks and to apply the newly developed techniques for assessment of landslide susceptibility to the study area of Yongin in Korea. Landslide locations were identified in the study area from interpretation of aerial Photographs and field survey data, and a spatial database of the topography, soil type and timber cover were constructed. The landslide-related factors such as topographic slope, topographic curvature, soil texture, soil drainage, soil effective thickness, timber age, and timber diameter were extracted from the spatial database. Using those factors, landslide susceptibility and weights of each factor were analyzed by two artificial neural network methods. In the first method, the landslide susceptibility index was calculated by the back propagation method, which is a type of artificial neural network method. Then, the susceptibility map was made with a GIS program. The results of the landslide susceptibility analysis were verified using landslide location data. The verification results show satisfactory agreement between the susceptibility index and existing landslide location data. In the second method, weights of each factor were determinated. The weights, relative importance of each factor, were calculated using importance-free characteristics method of artificial neural networks.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1166-1169
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• 1998

The Load characteristic of electric railway requires the power demand of the high capacity which amplitude is spacial-temporally fluctuated due to frequent starting and stopping with large tractive force. The conventional electric railway mainly consists of the resistance controlled and the thyristor controlled locomotives, are compensated for their bad characteristics of the power factor$(70\sim80%)$ with installation of another capacitor improving power factor at the substation. Since 1994, VVVF train car with good characteristics of power factor(100%) have been introduced and operated in Kwa-Chon Line. From the present technical tendency, it is judged that introduction of the locomotive with various controlled methods is necessary. The protective equipments installed at the substation are complicated and various aspects to detect faults and reduce their extension, so the universal countermeasures are required. Specially in the case of the fault occurrence it is difficult to calculate the fault location because of the change in the contactline constant according to modifying the characteristics of the contactline (the dualized catenary wire and extension, etc), so much time is required for the detection of fault location. In BT-fed method distance-relays and fault-locators are not installed, we have so many difficulties in the quick accident recovery.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.34-40
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• 2011

This paper is purposed to develop an leakage current detecting system(LCDS) which can prevent electrical fires on breaker capacity expansion as well as ruptures of XL(Extra long) pipelines and power failure by operation of ELB(Earth leakage breaker) at auto water machine in winter. In order to develop LCDS, this paper studied field state investigation, field state experiment, development of leakage alarm system and verification experiments. Field states investigation at livestock companies(10 companies) in cheong-won location to deduce the problems of auto water machine is analyzed. The field state experiment is conducted at B livestock company in cheong won location. The field state experiment method is measured with leakage current when ELB tripped by environment factor(fine, cloudy, and rainy day). The LCDS is developed as MCU(Micro Control Unit) part applied leakage current values at B livestock company. Verification experiments for the leakage current detecting system were conducted by two methods of current supply and field test. Results show that LCDS suggested in this paper are valuable and usable in auto water machine based on environment factor, which will prevent severe damage to human beings and properties and reduce the electrical fires in livestock.