• 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.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.274-275
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• 2009

An integral imaging system resorting to multiple birefringence lens arrays using Jones Matrix was analyzed and implemented. Each birefringence lens array was produced by placing a liquid crystal layer on a conventional lens array. Its depth of field was proved to be extended theoretically.

• Ocean Systems Engineering
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• v.9 no.4
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• pp.391-407
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• 2019

Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.253-263
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• 2021

This research aims to increase the tourism destination competitiveness for the city of Malang. This research uses the extended criteria of Resource-based View (RBV): VRIOLU (Valuable, Rare, Inimitable, Organization, Large Market, Unmet Need) to analyze tourism destination competitiveness for the city of Malang. A qualitative approach with a case study research design is adopted in this research. Data was collected using data triangulation, such as an in-depth interview with the informants, direct observation in the form of field notes, and picture documentation. The data was analyzed manually by the researchers using thematic analysis. In this research, VRIOLU, the extended criteria of RBV is proven that it can be used as a tool to analyze tourism destination competitiveness by giving the researchers a framework to get the answers from the informants to achieve the research aim. Suggestions to improve the tourism destination competitiveness for the city of Malang include: (1) Actively promoting the added value that can be given by the city of Malang to the visitors; (2) Forming a tourism board to manage the city of Malang as a tourism destination in a holistic manner; (3) Creating synergistic promotion between the stakeholders of tourism operator and governments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.82-92
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• 2012

This study proposed a new non-destructive evaluation method for concrete bridge deck deterioration using ground penetrating radar (GPR). To calculate dielectric constant of the concrete bridge deck, an extended common mid-point (XCMP) method was developed for a two-layered structure using an air-coupled GPR antenna setup. The deterioration conditions of the concrete bridge deck such as deterioration depth was evaluated based on the dielectric constant and surface-to-average dielectric constant ratio of the concrete bridge deck. A GPR field test was conducted on an old concrete bridge with asphalt concrete surfacing to validate the new evaluation method. The test results showed that the newly proposed method estimated pavement thickness and deterioration depth of the concrete deck in a reasonable level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.313-315
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• 2011

Smart phone camera module are mounted on the focus are 2 types depending on the behavior. AF (Auto focus) camera module and the FF (Fixed focus) camera module two are different types. AF camera module to move the location of the lens and is a way to automatically focus, FF camera module lens position of the focus is the way to a fixed state. EDOF camera module the location of the lens as a frozen state EDOF AF module using the algorithm to focus on applied technology is a module. In this paper, optimization EDOF camera module implementation of the resolution.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.40.3-41
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• 2021

Minor mergers leave behind long lived, but extremely faint and extended tidal features including tails, streams, loops and plumes. These act as a fossil record for the host galaxy's past interactions, allowing us to infer recent accretion histories and place constraints on the properties and nature of a galaxy's dark matter halo. However, shallow imaging or small homogeneous samples of past surveys have resulted in weak observational constraints on the role of galaxy mergers and interactions in galaxy assembly. The Rubin Observatory, which is optimised to deliver fast, wide field-of-view imaging, will enable deep and unbiased observations over the 18,000 square degrees of the Legacy Survey of Space and Time (LSST), resulting in samples of potentially of millions of objects undergoing tidal interactions. Using realistic mock images produced with state-of-the-art cosmological simulations we perform a comprehensive theoretical investigation of the extended diffuse light around galaxies and galaxy groups down to low stellar mass densities. We consider the nature, frequency and visibility of tidal features and debris across a range of environments and stellar masses as well as their reliability as an indicator of galaxy accretion histories. We consider how observational biases such as projection effects, the point-spread-function and survey depth may effect the proper characterisation and measurement of tidal features, finding that LSST will be capable of recovering much of the flux found in the outskirts of L* galaxies at redshifts beyond local volume. In our simulated sample, tidal features are ubiquitous In L* galaxies and remain common even at significantly lower masses (M*>10^10 Msun). The fraction of stellar mass found in tidal features increases towards higher masses, rising to 5-10% for the most massive objects in our sample (M*~10^11.5 Msun). Such objects frequently exhibit many distinct tidal features often with complex morphologies, becoming increasingly numerous with increased depth. The interpretation and characterisation of such features can vary significantly with orientation and imaging depth. Our findings demonstrate the importance of accounting for the biases that arise from projection effects and surface-brightness limits and suggest that, even after the LSST is complete, much of the discovery space in low surface-brightness Universe will remain to be explored.

• Journal of Navigation and Port Research
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• v.28 no.7
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• pp.619-627
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• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Ulsan Harbor and Ulsan New Port, etc. due to construction of New Port in Ulsan Bay. We also considered the increase of water depth at the entrance channel by dredging work up to 15 meters depth in order to see the dredging effect. Among several model analyses, the nonlinear and breaking wave conditions are showed the most applicable results. This type of trial might be a milestone for port development in macro scale, where the induced impact analysis in the existing port due to the development could be easily neglected.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.79-82
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• 2010

In optical imaging systems, such as microscopes, high resolution exposure systems, and optical storage devices, higher optical resolution is a requirement. One of the promising technologies that is able to satisfy this requirement with relatively simple construction and reliable performance are, solid immersion lens (SIL)-based near-field (NF) optical systems. High NA optical systems using annular apertures have been investigated as one solution to achieve higher resolutions and an extended focal depth. By applying an optimized annular aperture to convention SIL optical head resolution can be increased by approximately 20%. This novel SIL-based near-field optics will be verified through experiments such as measuring focused beam spot profiles and observing the topology of a measurement sample. The studied SIL-based near-field optics can be applicable to not only next generation optical storage device but also high resolution microscopy and pattering technologies.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.73-78
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• 1999

In general, the patients of the head and neck cancer are treated with 4MV photon beam up to prescribed dose, but spinal cord should be excluded in the treatment field. When its absorbed dose is limited at the tolerance dose. In case of the patients who has the positive posterior neck nodes need a boost electron beam treatment to the prescribed dose. In that case, the anatomical structure of the neck and the physical structure of the standard electron cone interrupt to allow proper access to the disease site. Therefore, we extended treatment SSD for the remove of the those hindrances. In this study, we evaluated the dosimetric variation of the standard electron cone for the extended SSD, from 100cm to 120cm, 5 cm increment, and compare to the custom-made electron cone. As a result, the $\%$ depth dose, the point of maximum dose and the range of maximum were changed within the $2\%$. The penumbra width was increased from 1.0cm to 2.0cm. However, the dosimetric characteristics of the custom-made electron cone was very similar to that of the 100cm SSD standard electron cone and due to its characteristic of physical structure, patients didn't need re-positioning after photon beam treatment, therefore accurate treatment was possible, we conclude that the custom-made electron cone was very useful for the clinical practice.