• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.512-519
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• 2023

Noise pollution poses significant challenges to human well-being and marine ecosystems. It is primarily caused by the flow around ships and marine installations, emphasizing the need for accurate noise evaluation of flow noise to ensure environmental safety. Existing flow noise analysis methods for underwater environments typically use a hybrid method combining computational fluid dynamics and Ffowcs Williams-Hawkings acoustic analogy. However, this approach has limitations, neglecting near-field effects such as reflection, scattering, and diffraction of sound waves. In this study, an alternative using direct method flow noise analysis via the lattice Boltzmann method (LBM) is incorporated. The LBM provides a more accurate representation of the underwater structural boundaries and acoustic wave effects. Despite challenges in underwater environments due to numerical instabilities, a novel DM-TS LBM collision operator has been developed for stable implementations for hydroacoustic applications. This expands the LBM's applicability to underwater structures. Validation through flow noise analysis in pipe orifice demonstrates the feasibility of near-field analysis, with experimental comparisons confirming the method's reliability in identifying main pressure peaks from flow noise. This supports the viability of near-field flow noise analysis using the LBM.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.203-213
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• 2019

The purpose of this study was to compare the anxiety, sexual attitudes, and sexual behavior according to smartphone use and contacts with obscene materials. 110 university students surveyed demographic characteristics, smartphone use, contacts with obscene materials, anxiety, sexual attitudes, and sexual behavior, and analyzed 102 questionnaires except missing and incomplete responses. The collected data were analyzed by independent t-test or chi-square test. Men were significantly more likely to have contacts with obscene materials, sexual attitudes, and sexual behavior than the women (p<.05). In type of residence, boarding room or lodging was significantly higher at time of smartphone use, anxiety, and sexual behaviors than the home (p<.05). There was no difference in variables according to religion (p>.05). There was no difference in variables according to the level of academic achievement (p>.05). Time of smartphone use over 3 hours was significantly higher for contacts of obscene materials, anxiety, and sexual attitudes and behaviors than less 3 hours (p<.05). Higher levels of time of contacts with obscene materials were significantly higher in anxiety and sexual behaviors than lower level (p<.05). The results of this study can be used as a basis for the development of intervention programs for those who are experiencing excessive smartphone use and contacts with obscene materials.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.249-258
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• 2019

The health care services are the most basic social institutions that are provided to citizen including disabled persons for improvement of health. However, the study of the difference of health care services according to the speech therapy use in the people with speech-language disorders was insufficient. The aim of this investigation was to compare the awareness of health care services and characteristics of people with speech-language disorders according to speech therapy use. The researchers selected 229 people with language disorder using raw data of National Survey of the Disabled Person (2017). We compared the characteristics and health care services of people with speech-language disorders by distinguishing between speech therapy non-users and speech therapy users. Among the 229 people with language disorder, speech therapy users were 37 persons (16.2%). In comparison with non-users, users were younger, more preschoolers, more family incomes, and intellectual disabilities and autistic disorder were the most common types of disability enrollment. Users had a lower proportion of unmet medical needs than non-users. For the reasons of unmet medical need, there were 6.8% and 6.3% of the "economic reasons" and "communication difficulties" Both users and non-users responded that "disability management services" need to be strengthened by the government. In conclusion, we suggest that access to health care services needs to be increased to lower the barriers of speech therapy use.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.385-400
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• 2019

We reviewed existing studies and proposed future research on the sustainability of short-term effects, and of the Yongin Emotion Management Training program (Y-EMT). In this study, we conducted Y-EMT to verify its effectiveness in relation to affective disorders associated with chronic schizophrenia. Thirty-five patients were assigned to the experimental group, and 35 to the control group. First, results of repeated-measures analysis supported the effectiveness of Y-EMT. Comparisons of the results on the pre-test with those for the 5-month and 1-year post-training tests showed significant differences in mean scores between the experimental and control groups. Furthermore, these differences persisted at the 2-year follow-up. Second, in the experimental group, interactions between emotional behavior and expression, self-efficacy, and changes in interpersonal relationships showed significant effects at 5 months after the program ended, and these effects continued to increase up to 1 year post-training. Taken together, the findings indicate that, to maintain the effects of therapy in patients with chronic schizophrenia, patients should undergo Y-EMT along with cognitive rehabilitation training and social skills training. Human relations training such as Y-EMT is most helpful for rehabilitation when it is paired with high levels of medication.

• (The) Research of the performance art and culture
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• no.41
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• pp.187-218
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• 2020

Ulsan Dutbeki is a local dance handed down by the Ulsan people through custom. This study was discussed on the locality of Ulsan Dutbeki. The method of this study is as follows. First of all, the perception of Dutbeki from the perspective of Ulsan's local characteristic. First, Ulsan Dutbeki is based on the local characteristic of the southeastern coastal area of the Korean peninsula. Second, Dutbeki features local characteristics of Ulsan as a military cultural area. Third, in Dutbeki, there is a local culture of Ulsan which was originated from the village Dongjeol and outdoor performances. Next, the researcher perceived Ulsan Dutbeki which had been handed down through custom and approached its shape. The origins of the shape are, firstly, the speech tone and gestures of Ulsan people. Secondly, folk plays related to worshiping martial arts and military training. Thirdly, the characteristics of the Dutbeki dance in coastal areas of Gyeongsangdo. Fourth, local custom displayed at the village festival of Ulsan. Ulsan is a region of Gyeongsang culture area and has similarity with other localities. However, this study limited its comparisons with regard to Dutbeki that were originated from the local characteristics of other regions. The results of this study recognized Ulsan Dutbeki as a local dance in Ulsan area. In other words, this study perceived Dutbeki, which had been an entertaining component of traditional lifestyle, as an intangible cultural heritage and studied the form in every conceivable way from an artistic point of view.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.82-82
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• 2003

Introduction: With the development of dose calculation algorithms for electron beams, 3D RTP systerns are available for electron beam dose distribution commercially. However, no studies evaluated the accuracy of dose calculation with ADAC Pinnacle system for electron beams. So, the accuracy of the ADAC system is investigated by comparing electron dose distributions from ADAC system against the BEAMnrc/DOSXYZnrc. Methods: A total of 33 breast cancer patients treated with 6, 9, and 12MeV electrons in our institution was selected for this study. The first part of this study is to compare the dose distributions of measurement, TPS and the BEAMnrc/DOSXYZnrc code in flat water phantom at gantry zero position and for a 10 ${\times}$ 10 $\textrm{cm}^2$ field. The second part is to evaluate the monitor unit obtained from measurement and TPS. Adding actual breast patient's irregular blocks to the first part, monitor units to deliver 100 cGy to the dose maximum (dmax) were calculated from measurement and 3D RTP system. In addition, the dose distributions using blocks were compared between TPS and the BEAMnrc/DOSXYZnrc code. Finally, the effects of tissue inhomogeneities were studied by comparing dose distributions from Pinnacle and Monte Carlo method on CT data sets. Results: The dose distributions calculated using water phantom by the TPS and the BEAMnrc/ DOSXYZnrc code agreed well with measured data within 2% of the maximum dose. The maximum differences of monitor unit between measured and Pinnacle TPS in flat water phantom at gantry zero position were 4% for 6 MeV and 2% for 9 and 12 MeV electrons. In real-patient cases, comparison of depth doses and lateral dose profiles calculated by the Pinnacle TPS, with BEAMnrc/DOSXYZnrc code has generally shown good agreement with relative difference less than +/-3%. Discussion: For comparisons of real-patient cases, the maximum differences between the TPS and BEAMnrc/DOSXYZnrc on CT data were 10%. These discrepancies were due in part to the inaccurate dose calculation of the TPS, so that it needs to be improved properly. Conclusions: On the basis of the results presented in this study, we can conclude that the ADAC Pinnacle system for electron beams is capable of giving results absolutely comparable to those of a Monte Carlo calculation.

• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.87-97
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• 2009

The seismic site coefficients are often used with the seismic hazard maps to develop the design response spectrum at the surface. The site coefficients are most commonly developed deterministically, while the seismic hazarde maps are derived probabilistically. There is, hence, an inherent incompatibility between the two approaches. However, they are used together in the seismic design codes without a clear rational basis. To resolve the fundamental imcompatibility between the site coefficients and hazard maps, this study uses a novel probabilistic seismic hazard analysis (PSHA) technique that simulates the results of a standard PSHA at a rock outcrop, but integrates the site response analysis function to capture the site amplification effects within the PSHA platform. Another important advantage of the method is its ability to model the uncertainty, variability, and randomness of the soil properties. The new PSHA was used to develop fully probabilistic site coefficients for site classes of the seismic design code and another sets of site classes proposed in Korea. Comparisons highlight the pronounced discrepancy between the site coefficients of the seismic design code and the proposed coefficients, while another set of site coefficients show differences only at selected site classes.

• Journal of the Korean Geotechnical Society
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• v.24 no.11
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• pp.61-70
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• 2008

Load settlement behaviors and load transfer characteristics of rock-socketed pile subjected bi-directional load at pile tip were investigated using bi-directional pile load tests (BD PLT) performed on ten large-diameter drilled shafts at four sites. Based on test results, additional pile-toe displacement ($w_{bs}$) by coupled soil resistance was analyzed, and thus equivalent top loaded load-settlement curve of pile subjected bi-directional load was proposed by taking into account the coupled soil resistance. Through comparisons with field case studies, it is found that for test piles there exists effect of coupled soil resistance, which is represented by wbs, and thus an equivalent curve obtained by existing uncoupled methods can overestimate bearing capacity of piles by BD PLT. On the other hand, the analysis by the proposed method with soil coupling effect has a considerably larger settlement when compared with the results by uncoupled load transfer method and estimates reasonable load-settlement behaviors of test piles. In case of pile socketed in high strength rocks, however, effects of coupled soil resistance can be neglected.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.19-29
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• 2009

In this study, a numerical analysis was performed to predict the sequential behavior of anchored retaining wall where the failure accident took place, and verified accuracy of prediction through the comparisons between prediction and field measurement. The emphasis was given to the wall behaviors and the variation of sliding surface based on the two different methods of elasto-plastic and finite element (shear strength reduction technique). Through the comparison study, it is shown that the bending moment and the soil pressure at construction stages produce quite similar results in both the elasto-plastic and finite element method. However, predicted wall deflections using elasto-plastic method show underestimate results compared with measured deflections. This demonstrates that the elasto-plastic method does not clearly consider the influence of soil-wall-reinforcement interaction, so that the tension force (anchor force and earth pressure) on the wall is overestimated. Based on the results obtained, it is found that finite element method using shear strength reduction method can be effectively used to perform the back calculation analysis in the anchored retaining wall, whereas elasto-plastic method can be applicable to the preliminary design of retaining wall with suitable safety factor.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.37-51
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• 2007

In this study, pile load tests have been carried out to develop new P-y curves and then, to investigate the effects of pile rigidities on laterally loaded offshore drilled shafts in Incheon marine clay. This paper consists mainly of two parts: the first part, performance of a series of lateral load tests on small- and full-scale piles under one- and two-way loadings and the second part, comparison between the measured and predicted results by using O'Neill's and Matlock's clay models. Based on the results obtained, it is shown that relatively good agreements in bending moments and lateral displacements were obtained between the measured results using calculated P-y curves and predicted ones by O'Neill's and Matlock's clay models. The cases were considered with varying rigidity factors based on pile diameter, length and subgrade soil reaction. Through comparisons, it is found that soil P-y curve influences highly the behavior of flexible pile rather than that of rigid pile.