• Geomechanics and Engineering
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• v.25 no.2
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• pp.135-142
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• 2021

This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.

• Journal of Distribution Science
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• v.21 no.2
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• pp.77-89
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• 2023

Purpose: At the end of the pandemic, many digital startups had negative performances. For that, this study aims to analyze the mediating role of entrepreneurial competence and digital entrepreneur career maturity. Seven hypotheses were proposed, namely the effect of entrepreneurship orientation, digital entrepreneurship experience, and digital entrepreneur career maturity on digital entrepreneurial competence, the effect of digital entrepreneurial experience on digital entrepreneurial career maturity, the influence of entrepreneurial orientation, entrepreneurial competence, and digital entrepreneur career maturity on business performance. Research design, data and methodology: The population is digital entrepreneurs in Central Java, Indonesia with a business duration of more than 4 years. The number of samples as many as 184 people were carried out by questionnaire distribution through face-to-face, email, and Google forms. Partial Least Square Structural Equation Modeling was used to test the path coefficient statistics. Results: The results showed that all the hypotheses proposed were accepted. Digital entrepreneurial competencies and digital entrepreneurial career maturity are also proven to have a mediating role. Conclusions: The findings of this study can contribute to the development of digital entrepreneurship research. Practically, the government's role is needed to facilitate the three main elements of digital business: e-commerce, payment methods, and distribution channels.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.61-70
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• 2016

This study intended to analyze the spatial distribution of two types of weeding song (Short Bang-a and Sangsa ryu) and how geomorphic elements influence the propagation of the songs in Chungcheongbuk-do area. The distribution of the two types of song was mapped as point data. According to the result, both types showed similar distribution pattern. In order to figure out the reason of this similarity, the distribution pattern of songs was analyzed at various scales based on geomorphic elements including river, mountain and lineament. The result showed that most of distribution pattern of songs followed the lineament direction. Also, the spatial continuity among mountain that was formed by large and small lineament in various directions could be the path of the cultural diffusion. If the lineament with same direction does not intersect other lineament that have different direction, spatial continuity would be blocked. Consequently it was confirmed that propagation of songs has not spread smoothly.

• Journal of computational fluids engineering
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• v.5 no.3
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• pp.8-15
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• 2000

This research is aimed to find out how the inlet angle of secondary air affects the uniformity of temperature distribution inside a small incinerator. A commercial code, PHOENICS, is used to simulate the thermal-flow field of an incinerator. The computational grid system is constructed by Multi-Block technique provided by PHOENICS. Numerical experiments are done with the five different angles of secondary air inlet. The uniformity of temperature distribution is evaluated by checking the standard deviation of temperature distribution in an incinerator. The computational results show that there is the minimum value of standard deviation at the certain angle of secondary air inlet, which means that there is an optimum angle of secondary air inlet that could improve the uniformity of temperature distribution in an incinerator. The optimum angle of secondary air inlet is between 30 degree and 45 degree in this particular case.

• Journal of Distribution Science
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• v.16 no.5
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• pp.61-70
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• 2018

Purpose - These days, an individual user, private entity, hears everyday news of hacking and personal information leakage in the era of a most-connected society. This study investigates cyber attack, cyber insurance and distribution channels for insurance goods in South Korea by analyzing various cases of cyber attacks in domestic and overseas case. Research design, data and methodology - This study adopted various study cases instead of the one large case for deep quality analysis, and focused on various cases of domestic and overseas cyber attacks with insurance. Result - As a result of analyzing the cases that were hacked, types of massive losses and damages arising out of internet blackout due to cyber risks are paralyzation of public and private website and portal, electronic administrative system, public infrastructure, and consequently a normal operation of nation is impossible. These losses and damages however can be coverable under cyber insurance. Conclusions - This paper suggests insurance carriers, as suppliers, should provide multiple channels to sell to the customer and should expand the strategy of advertisement and promotion in order for them to change their mind and compare the price and value of the information of individual users and private entity in view of cost savings.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.493-500
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• 2018

The distribution of standing wreaths has reached about 7.1 million per year and the size of the standing wreath market is estimated to be at least 700 billion won. Among them, 20 to 30 percent are estimated to be reused, resulting in damage to flowerfarms' sales of 110 to 160 billion won per year. Due to the unique characteristics of conventional 3-tier standing wreaths in terms of transportation and installation, companies that lack design expertise have monopolized local distribution markets, and the issue of illegally using standing wreaths has been raised. These issues have highlighted the need for developing new designs and establishing a distribution system to expand the consumption of flowers. This study was carried out to identify consumers' perception of reused standing wreaths and the current systems introduced to prevent the distribution of reused standing wreaths such as the real-name standing wreath production system, the authenticity certificate system, and new standing wreaths. The results of a consumer survey showed that consumers' perception of reused standing wreaths has been high and that reused standing wreaths need to be actively regulated to establish fair trade order and protect consumers' rights. Although the effectiveness of the real-name system, the authenticity certificate system, and new standing wreaths was found to be insufficient, the introduction of these systems was essential and necessary for continuous promotion through broadcasting media.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.37-40
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• 1983

Whole brain irradiation is one mode in the treatment of brain cancer and brain metastasis, but it might cause brain injury such as brain necrosis. It has been studied whether the dose distribution could be a cause of brain injury. The dose distribution in whole brain irradiated by Co-60 beam has been measured by means of calibrated TLD chips inserted in the brain of Humanoid phantom. The following results were obtained. 1. Dose distribution on each transverse section of the brain was uniform. 2. On the midsagital plane of the brain, the dose was highest in upper portion and lowest in lower portion, varying 8 from 104% to 90%. 3. When the radiation field includes free space of 2cm or more width out of the head, the dose distribution in the whole brain is almost independent of the field width. 4. It is important to determine adequate shielding area and to set shielding block exactly in repetition of treatment.

• Structural Engineering and Mechanics
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• v.56 no.2
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• pp.169-188
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• 2015

There are two types of nonlinear analysis methods for building frameworks depending on the method of modeling the plastification of members including lumped plasticity and distributed plasticity. The lumped plasticity method assumes that plasticity is concentrated at a zero-length plastic hinge section at the ends of the elements. The distributed plasticity method discretizes the structural members into many line segments, and further subdivides the cross-section of each segment into a number of finite elements. When a reinforced concrete member experiences inelastic deformations, cracks tend to spread form the joint interface resulting in a curvature distribution. The program IDARC includes a spread plasticity formulation to capture the variation of the section flexibility, and combine them to determine the element stiffness matrix. In this formulation, the flexibility distribution in the structural elements is assumed to be the linear. The main objective of this study is to evaluate the accuracy of linear flexibility distribution assumed in the spread inelasticity model. For this purpose, nonlinear analysis of two reinforced concrete frames is carried out and the linear flexibility models used in the elements are compared with the real ones. It is shown that the linear flexibility distribution is incorrect assumption in cases of significant gravity load effects and can be lead to incorrect nonlinear responses in some situations.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1435-1441
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• 2014

The fire took place in the synthetic heat transfer fluid boiler used in production process of medium density fiberboard. This study investigated pressure distribution of the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner. Pressure distribution at steady state in combustion furnace is 2~5mAq and pressure distribution at inverter under fault condition in combustion furnace is 10~-53mAq. The decrement of coil thickness measurement for synthetic heat transfer fluid boiler is 0~5mm.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.3
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• pp.7-13
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• 2019

To improve the flow distribution at channel locations in the welded plate heat exchanger with "L"-type inflow, the flow visualization of Model 1 was carried out. Besides, the characteristics of flow distribution was investigated experimentally according to the header shape. The inlet flow rate for each channel location was increased at the side channels but decreased at the central channels. In the case of Model 2, which has a slant structure added to the basic header of Model 1, the unevenness of inlet flow increased by 23% from 0.019 to 0.023 as compared to Model 1. On the other hand, Model 3, which has a baffle structure added to Model 2, showed 0.064 unevenness in inlet flow, which was a 36% reduction one compared to Model 1. To improve the distribution at each channel in the welded plate heat exchanger with "L"-type flow, it is necessary to improve the header external shape for the guide of flow as well as the baffle structure for reduction of vortex flow.