• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.11-19
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• 2016

Field observation for oceanic conditions and paralarvae of the common squid, Todarodes pacificus in Korean waters were sampled with the Bongo net (diameter: 60 cm, mesh size: $333{\mu}m$) by using oblique tow method with the oceanographic research vessel (Tamgu 12 and Tamgu 20) around Korean waters (middle of the Yellow Sea, northern part of the East China Sea, East Sea) in 2013 and 2014 was carried out. The observation in the Yellow Sea and the northern part of the East China Sea was done in August, 2013 and in the East Sea it was repeated at seven times from June, 2013 to September, 2014. The paralarvae in August of 2013 was not found in the Yellow Sea and one paralarvae was found in the northern part of the East China Sea. In the East Sea, 39 paralarvae during whole observation period were found, mantle length of paralarvae was from 1.7 to 13.5 mm. Surface water temperature in the Yellow Sea was $30^{\circ}C$, and cold water mass lower than $10^{\circ}C$ was occupied in the deep layer than 30 m. In the northern part of the East China Sea, surface water temperature was $31^{\circ}C$, and higher water temperature above $20^{\circ}C$ was found in deeper than 50 m. In the East Sea, optimum temperature for survival, $15-24^{\circ}C$, was existed shallower than 75 m.

• The Korean Journal of Petroleum Geology
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• v.1 no.1 s.1
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• pp.15-27
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• 1993

Seismic reflection profiles from the eastern continental margin of Korea delineate three major Neogene sedimentary basins perched on the shelf and slope regions: Pohang-Youngduk, Mukho and Hupo basins. The stratigraphic and structural analyses demonstrate that the formation and filling of these basins were intimately controlled by two phases of regional tectonism: transtensional and subsequent contractional deformations. In the Oligocene to Early Miocene, back-arc opening of the East Sea induced extensional shear deformation with dextral strike-slip movement along right-stepping Hupo and Yangsan faults. During the transtensional deformation, the Pohang-Youngduk Basin was formed by pull-apart opening between two strike-slip faults; in the northern part, block faulting caused to form the Mukho Basin between basement highs. As a result of the back-arc closure, the stress field was inverted into compression at the end of the Middle Miocene. Under the compressive regime, two episodes (Late Miocene and Early Pliocene) of regional deformation led to the destruction and partial uplift of the basin-filling sequences. In particular, during the second episode of compressive deformation, the Hupo fault was reactivated with an oblique-slip sense, which resulted in an opening of the Hupo Basin as a half-graben on the downthrown fault block.

• The Journal of Korean Society for Radiation Therapy
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• v.14 no.1
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• pp.175-186
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• 2002

The purpose of this study is directly measure and evaluate about absorbed dose change according to nominal energy and electron cone or medical accelerator on isodose curve, percentage depth dose, contaminated X-ray, inhomogeneous tissue, oblique surface and irradiation on intracavitary that electron beam with high energy distributed in tissue, and it settled standard data of hish energy electron beam treatment, and offer to exactly data for new dote distribution modeling study based on experimental resuls and theory. Electron beam with hish energy of $6{\sim}20$ MeV is used that generated from medical linear accelerator (Clinac 2100C/D, Varian) for the experiment, andwater phantom and Farmer chamber md Markus chamber und for absorbe d dose measurement of electron beam, and standard absorbed dose is calculated by standard measurements of International Atomic Energy Agency(IAEA) TRS 277. Dose analyzer (700i dose distribution analyzer, Wellhofer), film (X-OmatV, Kodak), external cone, intracavitary cone, cork, animal compact bone and air were used for don distribution measurement. As the results of absorbed dose ratio increased while irradiation field was increased, it appeared maximum at some irradiation field size and decreased though irradiation field size was more increased, and it decreased greatly while energy of electron beam was increased, and scattered dose on wall of electron cone was the cause. In percentage depth dose curve of electron beam, Effective depth dose(R80) for nominal energy of 6, 9, 12, 16 and 20 MeV are 1.85, 2.93, 4.07, 5.37 and 6.53 cm respectively, which seems to be one third of electron beam energy (MeV). Contaminated X-ray was generated from interaction between electron beam with high energy and material, and it was about $0.3{\sim}2.3\%$ of maximum dose and increased with increasing energy. Change of depth dose ratio of electron beam was compared with theory by Monte Carlo simulation, and calculation and measured value by Pencil beam model reciprocally, and percentage depth dose and measured value by Pencil beam were agreed almost, however, there were a little lack on build up area and error increased in pendulum and multi treatment since there was no contaminated X-ray part. Percentage depth dose calculated by Monte Carlo simulation appeared to be less from all part except maximum dose area from the curve. The change of percentage depth dose by inhomogeneous tissue, maximum range after penetration the 1 cm bone was moved 1 cm toward to surface then polystyrene phantom. In case of 1 cm and 2 cm cork, it was moved 0.5 cm and 1 cm toward to depth, respectively. In case of air, practical range was extended toward depth without energy loss. Irradiation on intracavitary is using straight and beveled type cones of 2.5, 3.0, 3.5 $cm{\phi}$, and maximum and effective $80\%$ dose depth increases while electron beam energy and size of electron cone increase. In case of contaminated X-ray, as the energy increase, straight type cones were more highly appeared then beveled type. The output factor of intracavitary small field electron cone was $15{\sim}86\%$ of standard external electron cone($15{\times}15cm^2$) and straight type was slightly higher then beveled type.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.132-142
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• 2014

This study is the first stage to identify distinctive characteristics of American Romantic Garden compared to English Romantic Garden. The purpose of the study is to identify characteristics of transitional garden in the early period of America by analyzing of Paca garden, Mount Vernon and Monticello when English Naturalistic Garden was firstly imported. The analysis studied historical background, people who designed garden, formal garden and characteristics of natural garden through reference. Also based on data through reference and field research, spatial configuration and garden factors of each site were analyzed. In spatial configuration, straight line and curve line, formal terrace and natural slope, visible axis and invisible axis, symetric and asymmetric, and perspective and oblique perspectives were used as analyzing factors. As a result of analysis, each garden showed different type from that of formal gardens from colony period, which is natural garden of asymmetric garden(English natural garden) coexisted. Paca garden which planned formal garden and natural garden in each space showed characteristics of each space, but in formal garden residential axis and garden axis does not coincide which shows it is out of formal garden type. Such phenomena and the fact that naturalistic garden coexist in the same garden shows that the formal garden type from early days in US is starting to change in different types. Mount Vernon garden, similar to Paca garden, was designed to have two different types of gardens in harmony rather than divide the space into different space and design it. It adapted serpent walkway but shows symmetric by central axis and considered formalistic plan through same materials. However through terrace in hills and spatial plan of oblique perspective, one could observe that naturalistic type was beginning to settle in US gardens. Through Monticello analysis, space was designed with major characteristics of naturalistic garden which is serpent walkway, ornamental farm, winding flower bed grove and bush and oblique perspective, and it completely duplicates characteristics of naturalistic garden which could not be found in gardens imported from UK.

• Journal of Korea Water Resources Association
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• v.48 no.5
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• pp.367-377
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• 2015

ADCPs have been highlighted so far for measuring steramflow discharge in terms of their high-order of accuracy, relatively low cost and less field operators driven by their easy in-situ operation. While ADCPs become increasingly dominant in hydrometric area, their actual measurement accuracy for velocity and bathymetry measurement has not been sufficiently validated due to the lack of reliable bench-mark data, and subsequently there are still many uncertain aspects for using ADCPs in the field. This research aimed at analyzing inter-comparison results between ADCP measurements with respect to the detailed ADV measurement in a specified field environment. Overall, 184 ADV points were collected for densely designed grids for the given cross-section that has 6 m of width, 1 m of depth, and 0.7 m/s of averaged mean flow velocity. Concurrently, ADCP fixed-points measurements were conducted for each 0.2m and 0.02m of horizontal and vertical spacing respectively. The inter-comparison results indicated that ADCP matched ADV velocity very accurately for 0.4~0.8 of relative depth (y/h), but noticeable deviation occurred between them in near surface and bottom region. For evaluating the capacity of measuring bathymetry of ADCPs, bottom tracking bathymetry based on oblique beams showed better performance than vertical beam approach, and similar results were shown for fixed and moving-boat method as well. Error analysis for velocity and bathymetry measurements of ADCP can be potentially able to be utilized for the more detailed uncertainty analysis of the ADCP discharge measurement.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.225-232
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• 2014

Purpose : The purpose of this study was to evaluate the surface and superficial dose for patients requiring postmastectomy radiation therapy(PMRT) with different treatment techniques. Materials and Methods : Computed tomography images were acquired for the phantom(I'mRT, IBA) consisting of tissue equivalent material. Hypothetical chestwall and lung were outlined and modified. Five treatment techniques(Wedged Tangential; WT, 4-field IMRT, 7-field IMRT, TOMO DIRECT, TOMO HELICAL) were evaluated using only 6MV photon beam. GafChromic EBT3 film was used for dose measurements at the surface and superficial dose. Surface dose profiles around the phantom were obtained for each treatment technique. For superficial dose measurements, film were used inside the phantom and analyzed superficial region for depth from 1-6mm. Results : TOMO DIRECT showed the highest surface dose by 47~70% of prescribed dose, while 7-field IMRT showed the lowest by 35~46% of prescribed dose. For the WT, 4-field IMRT and 7-field IMRT, superficial dose were measured over 60%, 70%, and 80% for 1mm, 2mm, and 5mm depth, respectively. In case of TOMO DIRECT and TOMO HELICAL, over 75%, 80%, and 90% of prescribed dose was measured, respectively. Surface and superficial dose range were uniform in overall chestwall for the 7-field IMRT and TOMO HELICAL. In contrast, Because of the dose enhancement effect with oblique incidence, The dose was gradually increased toward the obliquely tangential angle for the WT and TOMO DIRECT. Conclusion : For PMRT, TOMO DIRECT and TOMO HELICAL deliver the higher surface and superficial doses than treatment techniques based linear accelerator. It showed adequate dose(over 75% of prescribed dose) at 1mm depth in skin region.

• The Journal of the Acoustical Society of Korea
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• v.9 no.2
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• pp.42-52
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• 1990

A method of measuring impulse response of acoustic system, two kinds of cross-correlation methods (the direct correlation method and the M-sequence modulation correlation method) were applied. According to the direct correlation method, by using stationary random noise source and by calculating the cross-correlation function between the sourece and the output signal, equivalent impulse response can be obtained not being influenced by the back ground noises. By applying this method, the measurement of echo-time patterns in rooms and oblique incident sound absorption characteristics of sound absorbing materials was carried out. In the case of the M-sequence modulation correlation method which was contrived by Aoshima, an intermittent random nosie modulated by M-sequence signal is used as the source signal, and the cross-correlation function between the M-sequence signal and the squared output signal is calculated. According to this method, equivalent energy impulse response (squared impulse response) of te propagation system can be obtained without being influenced by the back ground noises and the air fluctuation caused by wind. As the applcaition of this measuring method to the architectural acoustics, the meaurements of echo-time patterns, reverberation decays and sound pressure lev디 distributions in rooms and sound insulation efficiencies in buildings were carried out. From these experimental studies, it has been found that this M-sequence modulation correlation method is markedly useful especially for the field masurement of sound insulation under high back ground noise condition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.132-142
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• 2000

The objective of this study is to experimentally investigate the noise propagating characteristics, the noise reduction mechanism and the performance of a slotted tube attached at the exit plane of a circular convergent nozzle. The experiment is performed through the systematic change of the jet pressure ratio and the slot length under the condition of two kinds of open area ratios, 25% and 51%. The open area ratio calculated by the tube length equivalent for the slot length is defined as the ratio of the total slot area to the surface area of a slotted tube. The experimental results for the near and far field sound, the visualization of jet structures and the static pressure distributions in the jet passing through a slotted tube are presented and explained in comparison with those for a simple tube. The propagating characteristics of supersonic jet noises from the slotted tube is closely connected with the slot length rather than the open area ratio, and its propagating pattern is similar to the simple tube. It is shown that the slotted tube has a good performance to suppress the shock-associated noise as well as the turbulent mixing noise in the range of a limited jet pressure and slot dimension. The considerable suppression of the shock‘associated noise is mainly due to the pressure relief caused by the high-speed jets passing through the slots on the tube. Both the strength of shock waves and the interval between them in a jet plume are decreased by the pressure relief. Moreover, the pressure relief is divided into the gradual and the sudden relief depending upon the open area ratio of the slotted tube. Consequently, the shock waves in a jet plume are also changed by the type of pressure relief. The gradual pressure relief caused by the slotted tube with the open area ratio 25% generates the weak oblique shock waves. On the contrary, the weak normal shock waves appear due to the sudden pressure relief caused by the slotted tube with the open area ratio 51%.

• 한국해양학회지
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• v.27 no.1
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• pp.66-77
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• 1992

Tidal sand ridges and sand waves are well developed in the Yellow Sea off Tae-An Peninsula, Korea. Their transport directions were inferred based on high resolution seismic profiles, surficial sediment characteristics and tidal regime. Tidal sand ridges are asymmetric, with long axes parallel to or slightly oblique to the dominant NE-SW tidal current direction. They show steep south and/or southeast flanks, which are in concordance with the apparent direction of internal cross-bedding in the south. Holocene sediments occur in accordance with distributional patterns of tidal sand ridges. These features indicate that Holocene active tidal sand ridges move toward the open sea in southeast, south and southwest direction. Sand waves which are distributed in flat sea floor with depth of about 40-60m show also asymmetric forms with a steep east-to-northeast face. Surficial sediments in the sand wave field are characterized by well sorted fine sands compared with poorly sorted adjacent areas. The sand waves appear to undergo easterly or northeasterly landward movement.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.162-168
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• 2007

For the past decade, the full-field digital mammography has been widely used for early diagnosis of breast cancer, and computer aided diagnosis has been developed to assist physicians as a second opinion. In this study, we try to predict the breast cancer using both mediolateral oblique(MLO) view and craniocaudal(CC) view together. A skilled radiologist selected 35 pairs of ROIs from both MLO view and CC view of digital mammogram. We extracted textural features using Spatial Grey Level Dependence matrix from each mammogram and evaluated the generalization performance of the classifier using Support Vector Machine. We compared the multi-view based classifier to single-view based classifier that is built from each mammogram view. The results represent that the multi-view based computer aided diagnosis in digital mammogram could improve the diagnostic performance and have good possibility for clinical use to assist physicians as a second opinion.