• Fire Science and Engineering
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• v.32 no.3
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• pp.51-59
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• 2018

Although a fire curtain plays an important role in preventing smoke from spreading to the auditorium in a theater fire, there has been insufficient research on fire curtains. In this study, to check the accuracy of numerical simulation, for previous experiments using a reduced scale model, a numerical simulation was carried out, and the results were compared with previous experimental data. The fire curtain effect was then predicted numerically. A Fire Dynamics Simulator (FDS) was used, and the natural exhaust vent sizes were set to ~10%, ~5%, and ~1% of the stage floor area. The smoke movement was visualized, and the mass flow rates and temperatures were measured and analyzed. In addition, the law of similarity was used to examine the influence of a fire curtain in a real scale theater fire. Without the fire curtain, the present numerical simulation results were in agreement with the previous experimental data within reasonable accuracy. Meanwhile, the fire curtain affects the mass flow rates through the natural exhaust vent and proscenium opening, as well as the start time of soot outflow to the auditorium. Overall, the present results can be used to develop a fire curtain system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2290-2299
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• 2009

This study aims to analyze the importances of various SCM adoption factors suggested in precedent researches with AHP. SCM adoption factors were categorized by four types: organization factor, transaction factor, relation factor, and information factor. Each factor has sub-factors. Organization factor has five sub-factors: adoption strategy, support of CEO, maturity of information technology, development of assessment system, and innovation leadership. Transaction factor has three sub-factors: transaction period, delivery/quality, and shared goal. Relation factor has five sub-factors: trust, collaboration, inter-dependence, conflict, and immersion. Information factor has three sub-factors: information quality, information share, and information exchange. There are sixteen sub-factors altogether. Analyzing the importances of SCM adoption factors with AHP, the importance of organization factor(.387) ranked the highest. Relation factor(.291), information factor(.167), and transaction factor(.155) followed. Putting the analysis results of primary hierarchy factors and secondary hierarchy factors together, support of CEO(.169) ranked the highest and trust(.124), adoption strateg (.089), share goal(.081), information exchange(.069), collaboration(.064), and information share (.057) followed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.609-617
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• 2016

In general, Personal Navigation Systems (PNSs) can be defined systems to acquire pedestrian positional information. GPS is an example of PNS. However, GPS can only be used where the GPS signal can be received. Pedestrian Dead Reckoning (PDR) can estimate the positional information of pedestrians using Inertial Measurement Unit (IMU). Therefore, PDR can be used for GPS-disabled areas. This paper proposes a PDR scheme considering various movement types over GPS-disabled areas as combat environments. We propose a movement distance estimation scheme and movement direction estimation scheme as pedestrian's various movement types such as walking, running and crawling using IMU. Also, we propose a fusion algorithm between GPS and PDR to mitigate the lack of accuracy of positional information at the entrance to the building. The proposed algorithm has been tested in a real test bed. In the experimental results, the proposed algorithms exhibited an average position error distance of 5.64m and position error rate in goal point of 3.41% as a pedestrian traveled 0.6km.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.543-551
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• 2016

Recently, the cultural industry has become an attractive industry which is having a dramatic effect with the rise of Hallyu offering many possibilities for development. Specially, the marketing techniques employed by the performing arts industry started to change to respond to consumer tastes and demands like other commodity markets, as the popular performing arts industry began to receive attention as a promising industry. It is important to identify the behavior of consumers in order to actively deal with the demands and tastes of consumers that are becoming increasingly diverse and individualized. The performing arts market needs to recognize the importance of its audience and to apply appropriate marketing techniques. This study attempted to empirically identify the value of performing arts perceived by the audience and to investigate the influence of the relationship between the perceived value, attitude formation and satisfaction with performing arts. In order to examine the influence of the value of performing arts on attitude and customer satisfaction, a reliability analysis and factor analysis were conducted to investigate the dependability and validity of the measured variables. In order to achieve the study's intended purpose, the structural equation model (SEM) was utilized as the core analysis method. As a result, it was found that the perceived value and attitude towards performing arts have a positive effect on customer satisfaction. The results of this study are expected to be used as the basic data for organizations that plan performances to improve their marketing and promotion around the audience and for more specific and detailed research in the future.

• Korean Journal of Remote Sensing
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• v.19 no.4
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• pp.277-284
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• 2003

We present a GPS-derived regional ionosphere model, which estimates Total Electron Content (TEC) in a rectangular grid on the spherical shell over Korea. After dividing longitude and latitude over Korea with 1$^{\circ}$$\times$1$^{\circ}$ spatial resolution, the TEC at the vertex of the grid was estimated by the Kalman filter. The GPS data received from nine nationwide GPS stations, operated by Korea Astronomy Observatory (KAO), were used for this study. To reduce inherent noises, the pseudorange data were phase-leveled by a linear combination of pseudoranges and carrier phases. The solar-geomagnetic reference frame, which is less variable to the ionosphere movement due to the Sun and the geomagnetic field than an Earth-fixed frame, was used. During a quiet time of solar activity, the KAO's regional ionosphere map indicated 30-45 Total Electron Content Unit at the peak of the diurnal variation. In comparison with the Global ionosphere Map of the Center for Orbit Determination in Europe, RMS differences were at the level of 4-5 TECU for five days.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.744-753
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• 2021

This study suggests ways to improve the standard test method and judgment criterion for the "Eco-toxicity Test" based on the rules and regulations provided in 'performance and qualifying test standards for marine pollution prevention materials and chemicals' in the Republic of Korea. Compared with the relevant references of other countries, this study attempted to find the limitations in the existing standards. As for the growth inhibition test of algae using Skeletonema costatum as an indicator, applying comparative analysis to measure specific growth rates, together with statistical analysis, instead of applying current methods, judged by the appearance of colors from the culture medium was suggested. Considering the exponential growth phase of the test species, the test duration was suggested to be reduced to less than four days. For the test with fish as an indicator, resetting the appropriate body size was suggested to, show consistent sensitivity against chenicals applied during testing. Furthermore, it is necessary to consider the criteria needs, which should be established in reasonable and objective ways. For the testing species, marine rotifer, Brachionus plicatilis could be a replacement for Artemia sp., and a bivalve for fish in the test. To improve the performance effectiveness of the "Eco-toxicity test", it is worth considering the designation of accredited testing institutes, by placing it in the same loop. Thus it is also expected to have a reliable management system in place, having the capacity of cost calculation properly and adjusting testing items if required.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.281-289
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• 2021

This study aims to investigate the influence of the components of the startup ecosystem on the business performance of startups, focusing on the mediating effect of the location environment. By presenting the insight that the popularization of start-ups can be an alternative for job creation thanks to the government's start-up support policy considering the location environment, it is possible to construct an optimal configuration scenario between the components of the start-up ecosystem and the location environment. Furthermore, it is expected to contribute to the improvement of corporate management performance. To achieve this goal, we performed a survey and the subjects were domestic start-up company employees with less than 7 years of experience. The results show that the components of the start-up ecosystem had a significant effect on the business performance of start-up companies and the location environment and on the management performance of start-up companies according to the mediation of the location environment.

• Journal of agricultural medicine and community health
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• v.43 no.4
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• pp.224-233
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• 2018

Objectives: This study was conducted to identify the relations between multiple chronic diseases and peridontal diseases in Korean adults. Methods: A total of 4,142 cases was set for analysis, who aged 35 and over and finished with the third year health survey and oral health check-up of the fifth Korea National Health and Nutrition Examination Survey(2012). Peridontal disease was defined if community periodontal index(CPI) was 3(formation of paradental cyst of more than 4mm) or 4(formation of paradental cyst of more than 6mm). Results: The subjects consisted of 48.5% male and 51.5% female. The prevalence rate of peridontal disease was found to be 30.1% in total. In peridontal disease the more the age increased, and the lower the education level and income level as well as the more where the residential area was rural, the higher the prevalence rate was(p<0.01). According to the number of multiple chronic conditions the prevalence rate of periodontal disease accounted for 27.8%, 31.9%, 33.1%, and 35.2% when there were 0, 1, 2, and 3 or more chronic diseases respectively. As a result of logistic regression analysis, gender, age, education level, residential area, current smoking, and use of oral hygienic products were found to be significant factors on peridontal disease. Conclusions: This research revealed the prevalence rate of peridontal disease was 30.1% in Korean adults and health behaviors affecting on periodontal disease were more significant.

• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.166-171
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• 2019

Aids to Navigation(AtoN) Accident can reduce the credibility of AtoN by adding extra works to the administrators, and cause burdens and inconveniences to the users during their navigation leading to social costs (or economic losses). Prior research on social cost estimation model to determine the Encounter cost, Administrative cost and Risk cost on the Aton model was done to estimate the economic losses due to AtoN Accident. However, this research could not provide adequate study results on risk cost estimates. Therefore, this study complements the estimation model presented in the previous study, and the estimated social cost of 249 AtoN Accidents that occurred during the last 10 years (2008-2017) in the Busan Regional Office of Oceans and Fisheries jurisdiction area. The risk cost was estimated using contingent valuation method since the AtoN is a non-market goods. As a result, the social cost of AtoN Accidents for the past 10 years was estimated to total 12.4 billion won including Encounter cost of 3.1 billion won (25.38%), Administrative cost of 1.7 billion won (13.62%), and Risk cost of 7.5 billion won (61.01%).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.299-302
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• 2014

Due to the convergence between digital devices and the development of wireless communication technology, bit-signal sensor miniaturization, building an Electronic Medical Record (EMR) which is a digital version of a paper chart that contains all of a patient's medical history and the information of Electronic Health Record (EHR), Ubiquitous healthcare (u-Healthcare) that can monitor their health status and provide personal healthcare service anytime and anywhere. Also, the appearance of cloud computing technology is one of the factors that accelerate the development of u-healthcare service. However, if the individual information to be used maliciously during the u-healthcare service utilization, leads to serious problems directly related to the individual's life because if it goes beyond the level of simple health screening and treatment, it may not provide accurate and reliable healthcare services. For this reason, we analyzed a variety of security issues related to u-healthcare service in cloud computing environment and described about directions of secure health information sharing system construction. In addition, we suggest the future developmental direction for th activation of u-healthcare industry.