A study on the estimation of wind noise level using the measured wind-speed data in the coastal area of the East Sea (동해 연안에서 관측된 풍속자료를 이용한 바람소음준위 추정 연구)
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- The Journal of the Acoustical Society of Korea
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- v.38 no.4
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- pp.378-386
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- 2019
Unlike ship noise that radiates from moving ships, wind noise is caused by breaking waves as a result of the interaction between the wind and the sea surface. In this paper, WNL (Wind Noise Level) was modeled by considering the noise source of the wind as the bubble cloud generated by the breaking waves. In the modeling, SL( Source Level) of the wind noise was calculated using the wind-speed data measured from the weather buoy operated in the coastal area of the East Sea. At the same time as observing the wind speed, NL (Noise Level) was continuously measured using a self-recording hydrophone deployed near the weather buoy. The modeled WNL according to the wind speed and the measured NL removing the shipping noise from the acoustic raw data were compared in the low-frequency band. The overall trends between the modeled WNL and the measured NL were similar to each other. Therefore, it was confirmed that it is possible to model the WNL in the shallow water considering the SL and distribution depth of bubble cloud caused by the wind.
Due to the recent economic downturn caused by Covid-19 and the unstable international situation, many investors are choosing the derivatives market as a means of investment. However, the derivatives market has a greater risk than the stock market, and research on the market of market participants is insufficient. Recently, with the development of artificial intelligence, machine learning has been widely used in the derivatives market. In this paper, reinforcement learning, one of the machine learning techniques, is applied to analyze the scalping technique that trades futures in minutes. The data set consists of 21 attributes using the closing price, moving average line, and Bollinger band indicators of 1 minute and 3 minute data for 6 months by selecting 4 products among futures products traded at trading firm. In the experiment, DNN artificial neural network model and three reinforcement learning algorithms, namely, DQN (Deep Q-Network), A2C (Advantage Actor Critic), and A3C (Asynchronous A2C) were used, and they were trained and verified through learning data set and test data set. For scalping, the agent chooses one of the actions of buying and selling, and the ratio of the portfolio value according to the action result is rewarded. Experiment results show that the energy sector products such as Heating Oil and Crude Oil yield relatively high cumulative returns compared to the index sector products such as Mini Russell 2000 and Hang Seng Index.
This thesis is a study on the kaftan styles iin Asia. The purpose of he study was to examine the origin o the kaftan concentrating on the history and cultural backgrounds of nomads in he Western Central and North Eastern Asia. Secondly for more thorough study and expla-nation on how these kaftans contributed to East-West trade along the silk road. wall paintings and miniature illuminations along Oasis roads persia and Saracen period were compared, Also real kaftans were compared and analyzed the characteristics of Western (Turkey palestine) Central(Kazakistan Uz-bekistan Tadzhistan Qyrgyztan Turkmenistan) and the North Eastern Asian(Mongol) area. Thirdly an attempt has been made to provide the North Eastern Asian(Mongol) area. Thirdly an attempt has been made to provide the style classifications according to their peculiarities of the various kaftans as well as how kaftan gave important influences on custumes of different religious sects. The kaftan is a long coat-like garment with front openings fastened with long sash having an extra long sleeves which were worn by middle and high class nomadics throughout the West Central and North Eastern Asia This type of kaftans were a basic clothing for nomadics since they were constantly moving fromone to another areas on their horse back riding. They also wore tight trousers with boots. Kaftans seem to be originated from nomads of Steppe around B.C. 800 On B. C 400 west asian areas such as Solokha Kul-oba Kulogan had pictures sculptues on vases showing kaftans of half coat type length with front opening tied with band. Also the materials used were the products of animals such as wool or felt with animal designs showing Scythian nomads. In the North Eastern Asia Hsiung-Nu were active in Kazakha North Altai and Mongol The Clothing and fabrics exfavated near Noin-ula Pazyrik showed many samples of kaftan with trousers with other interment be-longings with a corpse around B.C 300 to A. D 100 when trades along the silk roads were proven by many historians Kaftans excavated in this area wore red front opening silk materials which suggesting settling down of nomads. in he central Asia Dol-gull near Altai mountain area were mainly miners who later had many trades with Persia and Bizantine. After Dol-gull Bezeklik temple Samarkant Kizil cow Budda sculture wall paintings of Astana tomb showed typical kaftan of this re-gion. These were both hip covered length as well as long coat with narrow sleeves. Es-pecially they had different color band fron the main kaftan with grogeously and splendously designed silk. In perusia during A. D 1400 to 1600 minia-ture illumination showed kaftan as a high class symbol more than clothing purpose. They had best quality silk with extra long sleeves draping and had a layers of kaftans one on top of anther as a symbol of wealth These Kaftans with different colors and designs were even more beautiful with their effective combinations and contrast of colors. On the other hand the lower class common people and servants wore simple kaftan with the front part of the kaftan were slipped into the belt in order to be more active and con-venient to work, The real kaftans discovered at Topkapi Saray palace of Turkey from A. D 1300 to 1900 were also compared. These kaftans were very numerous in numbers as well as designs The materials and designs used were also vari-ous such as Chinese to Italian silk. The shaped and pattern itself were not much different from the previous nomad's Kaftans. The Palestian kaftans remained were from the beginning of 19th and 20th century. Since this area is hot and dry desert they used black and navy blue colors mostly in order to exclude the sun lights. The patterns used were similar to Nomads and Bedouin with cross stiches and patch work decorations. In the central Asia they had similar life style and natural environmental cnditions with Turkish tribe which resulted in similar kaftan styles as nomads. Mongols conserved basic patterns of kaftan since Cinggis Khan with deep folding in order to keep warm. At last the kaftans studided in this thesis were classified in to four such as half coat long coat jacket and vest style. A pattern used in the Central Asia were zigzag and ani-mal design whereas in the West Asia were floral plant arabesk and circle pattern. As I discussed previously kaftan styles of nomads in the Asia maintained its basic pat-tern throughout the history except slight changes in color gusset sleeve shapes. These slight changes were made according to the need to adapt the need of environmental natu-ral conditions, The reason for aboriginality of kaftan in Asia was its simplicity and con-venience Most interesting fact is that for all these years Mongols are still wearing kaftan in their life ensuring us that they art the preserves of old kaftan. Since this thesis dealt enormous Asian regions I had a limitation of not being able to cover the Far Esatern asian areas such as Korea China and Japan how these kaftans were influenced in their clothing history as well as Eastern and Western culture. This topic along with the studies on materials and designs of patterns of kaftan will be another research project in the future.
Sea level and atmospheric pressure data of 1999-2005 from four stations along the Korean east coast were analyzed to understand the sea level variability and its causal mechanism. The results of the wavelet and the auto-spectrum analyses indicate that the sea level fluctuations of 3-17 day period are statistically significant at the 95% confidence level, especially in spring to early summer. In this period, the coherency between the sea levels and the atmospheric pressures in a cross-spectrum is high, implying the importance of an inverted barometric effect in generation of the sea level fluctuations. To learn about the sea level variability, the cross-spectrum analyses were applied between the sea levels of the adjacent stations. The results show a case of southward phase propagations along the coast, as in 1999, 2003 and 2005, and an another case of no progressive phase lags between the stations, as in 2000-2002, and 2004. The phase speed in the former case is 12-15 m/s, which is a commonly observed phase speed of coastal Kelvin waves. Generation of such fluctuations seems to be related to low pressure cells developed in the Asian continent in spring and summer and moving eastward over the coastal region north of the stations. The latter case of no progressive phase lag, however, occurs when the low pressure cells developed in the continent move along the region south of the stations. In this case, the northeastward phase propagation with a speed of 5-8 m/s is observed along the southwestern coast of Japan.
Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70