• Journal of the Korean Society of Propulsion Engineers
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• 제18권5호
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• pp.43-53
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• 2014

Shock tunnels are known to be capable of simulating flow-field environments of supersonic and hypersonic flights. They have been operated successfully world-wide for almost half a century. As a consequence of the strong interest in hypersonic vehicles in Korea, attention has been given on this type of facility and so an intermediate-sized shock tunnel has lately been built at KAIST. In the light of this, this paper presents our tunnel performance and some of the model scramjet test data. The freestream flow used in this work replicates a supersonic combustor environment for a Mach 5.7 flight speed.

• Journal of the Korea Society of Computer and Information
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• 제11권3호
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• pp.141-149
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• 2006

In this paper, we introduce an improved algorithm for computing matrix triple product that commonly arises in primal-dual optimization method. In computing $P=AHA^{t}$, we devise a single pass algorithm that exploits the block diagonal structure of the matrix H. This one-phase scheme requires fewer floating point operations and roughly half the memory of the generic two-phase algorithm, where the product is computed in two steps, computing first $Q=HA^{t}$ and then P=AQ. The one-phase scheme achieved speed-up of 2.04 on Intel Itanium II platform over the two-phase scheme. Based on memory latency and modeled cache miss rates, the performance improvement was evaluated through performance modeling. Our research has impact on performance tuning study of complex sparse matrix operations, while most of the previous work focused on performance tuning of basic operations.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.165-172
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• 1999

In the present work , the transport mechanism of a capsaicin derivative, DA-5018, through blood-brain barrier (BBB) has been investigated to evaluate the feasibility of potential drug development. The result of pharmacokinetic parameters obtained from the intravenous injection of plasma volume marker,$[3^H]RSA$ and $[{14}^C]DA-5018$, indicated that both AUC, area under the plasma concentration curve and VD, volume of distribution in brain of $[3^H]RSA$ agreed with those reported ($1620{\pm}10 $percentage injected dose minute per milliliter (%IDmin/ml) and $12.0{\pm}0.1{\mu}l/g$, respectively). Elimination half-life and AUC of $[{14}^C]DA-5018$is corrected by the PHLC analysis, 19.6$\pm$1.2 min and 7.69$\pm$0.85% IDmin/ml, respectively. The metabolic rate of $[{14}^C]DA-5018$was very rapid. The blood-brain barrier permeability surface area (PS) product of $[{14}^C]DA-5018$ was calculated to be 0.24$\pm$0.05 $\mu$l/min/g. The result of internal carotid artery perfusion and capillary depletion suggested that [14C]DA-5018 pass through BBB with the time increasingly. Investigation of transport mechanism of $[{14}^C]DA-5018$ using agonist and antagonist suggested that vanilloid (capsaicin) receptor did not exist in the BBB, and nutrient carrier system in the BBB has no effect on the transport of DA-5018. In conclusion, despite the fact that penetration of DA-5018 through BBB is significant, the intact drug found in the brain tissue is small because of a rapid metabolism. Therefore, for the central analgesic effect of DA-5018, the method to increase the metabolic stability in plasma and the brain permeability should be considered.

• Safety and Health at Work
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• 제12권4호
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• pp.439-444
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• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

• Cross-Cultural Studies
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• 제46권
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• pp.281-296
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• 2017

Andrei Amalrik's plays are a unique phenomenon in the 70 years' history of Soviet drama. Half a century after the Soviet theater had intentionally forgotten its own achievements of avant-garde dramaturgy in the early 20th century, his bizarre plays suddenly emerged in the Soviet theater environment, completely separated from contemporary Western practices of the experimental theater. Surprisingly even now, Amalrik's plays have almost been forgotten not only in Russia but also by foreign Russian literary scholars. Amalrik's autobiographical essay is his only book published in Russia after the collapse of the Soviet regime. There is no collection of his works, and reevaluation of his work is not found even in Russia. However, Amalrik is a writer who should get a proper evaluation. The purpose behind studying his plays is to restore the tradition of Russian grotesque-absurd dramaturgy, which has been inherited from Gogol, Khlevnikov, Mayakovsky, and Oberiu. In this paper, we will analyze the mechanism of composition in Amalrik's plays.

• Journal of Convergence for Information Technology
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• 제9권8호
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• pp.53-62
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• 2019

This study is a descriptive study to investigate the relationship between verbal violence type, emotional response and coping in the operating room nurse. The subjects of the study were 400 nurses working in 20 general hospitals and 372 nurses in the operating room. As a result of the analysis, it was found that the perpetrators of the verbal violence experienced by the subject were physicians, direct supervisors, and more than half of the subjects were considering the transition. The most frequent cases of language violence were when the equipment was inoperable or not used during surgery, There were significant differences in verbal violence experience according to marriage, clinical career, and work style. Language violence emotional response showed significant difference with gender, position and coping, age, academic background, clinical career, and position. There was a significant correlation between experience of verbal violence and emotional response, emotional response and coping. Therefore, the results of this study will contribute to the development of coping strategies and prevention education programs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.513-515
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• 2014

Ultra High Definition(hereafter UHD), Next-generation video technology, was quickening in the request of many years of the recipient and the authors who have been towards the higher sense of reality. The change of the medium has resulted in a mutation in the detailed content and the point of view overlooking the world as evidenced through the history. Thus the emergence of UHD will also be expected to require to manufacture unique technology. Therefore, this paper, especially in the documentary among the video content, tries to study the changes in the manufacturing process by UHD video technology. Moreover UHD video screen technology such as high resolution tries to analyse for the fitness for purpose of the documentary that transmission of the accuracy and the change from a documentary video production. In addition, I try to explore the improvement in the choice of shooting material expected to be a problem, even for the advance of the work on the second half and backup according to the enormous data. We derive the developmental aspects that UHD video technology in documentary production is brought about by the research plan described above. It is intended to contribute to the development of content production with the development of technology.

• Safety and Health at Work
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• 제10권3호
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• pp.370-376
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• 2019

Background: Respirator fit testing is a method to assess if the respirator provides an adequate face seal for the worker. Methods: Workers from four Norwegian smelters were invited to participate in the study, and 701 respirator fit tests were performed on 127 workers. Fourteen respirator models were included: one FFABE1P3 and 11 FFP3 respirator models produced in one size and two silicone half masks with P3 filters available in three sizes. The workers performed a quantitative fit test according to Health and Safety Executive 282/28 with 5-6 different respirator models, and they rated the respirators based on comfort. Predictors of overall fit factors were explored. Results: The pass rate for all fit tests was 62%, 56% for women, and 63% for men. The silicone respirators had the highest percentage of passed tests (92-100%). The pass rate for the FFP3 models varied from 19-89%, whereas the FFABE1P3 respirator had a pass rate of 36%. Five workers did not pass with any respirators, and 14 passed with all the respirators tested. Only 63% passed the test with the respirator they normally used. The mean comfort score on the scale from 1 to 5 was 3.2. The respirator model was the strongest predictor of the overall fit factor. The other predictors (age, sex, and comfort score) did not improve the fit of the model. Conclusion: There were large differences in how well the different respirator models fitted the Norwegian smelter workers. The results can be useful when choosing which respirators to include in respirator fit testing programs in similar populations.

• Safety and Health at Work
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• 제10권3호
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• pp.260-264
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• 2019

Background: Professional dance is a physically demanding career path with a high injury prevalence, yet an ingrained culture of hiding or pushing through injuries. Developing better knowledge surrounding the cultural beliefs and behaviors related to injury reporting is critical to understand their incidence and burden. Therefore, the aim of this study was to investigate injury fear and injury reporting behaviors in professional dancers in Australia. Methods: This study utilized data collected in a cross-sectional survey of professional dancers in Australia. Descriptive analysis of injury fear and reporting stigma are presented with comparisons between subgroups (full-time versus part-time dancers; men versus women) conducted using two-sided Fisher's exact tests. Results: A total of 146 professional dancers were included. Over half (63%) of the respondents reported that they fear sustaining a dance-related injury, that they believe there is still a stigma surrounding injuries in dance (62%), and that this stigma has led to a delay in reporting or seeking care for an injury (51%). A lower proportion of part-time than full-time dancers reported that they would usually tell someone within their dance employment about an injury (35.1% vs. 59.6%, p = 0.006). Conclusion: Professional dancers are at risk of losing contracts or roles if they are injured, and therefore, it is common to dance through their occurrence. Many dancers, particularly those dancing part-time, are unwilling to tell their employers about their injuries. Action is required to improve this culture regarding injury reporting and help seeking for more effective injury understanding, prevention, and management in dance.

• Korean Journal of Construction Engineering and Management
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• 제20권3호
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• pp.97-104
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• 2019

The construction industry is heavily dependent on labor force as automation to building constructions is difficult due to its characteristics such on-site production, custom manufacturing production. Thus, while securing and fostering high-quality functional manpower for stable construction work are significant, the construction workforce has been persistently lacking compared to demand. Young workers are reluctant to enter the construction industry due to high labor intensity, unstable employment structure, and uncertainty for the future. The employment rate for new jobs in the construction industry is half as high as in others. Currently, the departments related to construction are organized in specialized high school to conduct training for young workers. The graduates have a low ratio of employment rate to the construction industry and functional capacities fallen short of expectations. In this study, the education and training conditions of specialized high schools were analyzed to derive problems and key improvements of the education system were drawn. As an improvement for the analysis results, it provides solutions such as giving advantages of previous education experience, expand industry-academic cooperation with businesses, and expand links with external educational institutions.