• Electrical & Electronic Materials
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• v.10 no.9
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• pp.881-888
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• 1997

This study demonstrats the profiles of phosphorus ions in silicon by MeV implantation(1∼3 MeV). Implanted profiles could be measured by SIMS(Cameca 4f) and compared with simulation results(TRIM program and analytical description method only using on Pearson function). The experimental result in the peak concentration region has a little bit deviation from simulation data. By RBS and Channeling measurements the defect distribution of implanted samples could be measured and spectrum are calibrated depth with RUMP simulation By XTEM measurement the thickness of defect zone also could be measured. Finally thermal annealing for the electrical activation of implanted ions carried out by RTA(rapid thermal annealing). The concentration-depth profiles after heat treatment was measured by SR(spreading resistance)-method.

• 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 Korean Vacuum Society Conference
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• 2012.02a
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• pp.274-274
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• 2012

In-depth analysis by secondary ion mass spectrometry (SIMS) is very important for the development of electronic devices using multilayered structures, because the quantity and depth distribution of some elements are critical for the electronic properties. Correct determination of the interface locations is critical for the calibration of the depth scale in SIMS depth profiling analysis of multilayer films. However, the interface locations are distorted from real ones by the several effects due to sputtering with energetic ions. In this study, the determination of interface locations in SIMS depth profiling of multilayer films was investigated by Si/Ge and Ti/Si multilayer systems. The original SIMS depth profiles were converted into compositional depth profiles by the relative sensitivity factors (RSF) derived from the atomic compositions of Si-Ge and Si-Ti alloy reference films determined by Rutherford backscattering spectroscopy. The thicknesses of the Si/Ge and Ti/Si multilayer films measured by SIMS depth profiling with various impact energy ion beam were compared with those measured by TEM. There are two methods to determine the interface locations. The one is the feasibility of 50 atomic % definition in SIMS composition depth profiling. And another one is using a distribution of SiGe and SiTi dimer ions. This study showed that the layer thicknesses measured with low energy oxygen and Cs ion beam and, by extension, with method of 50 atomic % definition were well correlated with the real thicknesses determined by TEM.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.2
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• pp.1-8
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• 2002

The aim of this study was to generate systemic data for the aquatic plant distribution according to water depth and crossing slope in the shoreline. The results of this study were as follows; 1. Anxiety to 0 near area Bidens frondosa, Scirpus tabernaemontani, Carex dispalata etc. total class 21 observe, and Phragmites communis, Iris pseudoacorus etc. class 6 of anxiety 0-70cm extent examined. Class 21 of anxiety observed all such as Bidens frondosa, Scirpus tabernaemontani, Carex dispalata in near area to 0, and Phragmites communis, Iris pseudoacorus etc. class 6 of anxiety 0-70cm extent examined. Anxiety 70-100cm extent Nymphoides indica, Ttapa japonica etc.. class 2 appeared to line Zizania latifolia, Typha angustata back 2 papers, 130cm and examined that Nelumbo nucifera was limit anxiety state 230cm. 2. Aquatic plants of Phragmites communis, Zizania latifolia, Typha angustata etc. range mainly to gentle gradient of slant 10 degree low and distribution pattern was ranging by Zizania latifolia, Typha angustata, Phragmites communis period of ten days from deepwater place. Nelumbo nucifera was forming become independent stock keeping away invasion of plant that ability to breed was different because was prosperous. Slant 10 bores was growing near sleep in been strange steep slope earth and distribution of emerged plant appeared punily and emerged plant and swampy land plant were ranged extensively in gentle gradient of 10 degree low. 3. On lake surrounding plant when wish to do distribution of natural conditions reference need to. That is, gentle gradient and distribution form of steep slope earth are different, and same pitch must consider enough this because appear as distribution, distribution according to that some plant species were growing was different.

• Journal of Information Processing Systems
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• v.5 no.1
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• pp.33-40
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• 2009

Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

• Journal of the Korean Geotechnical Society
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• v.25 no.5
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• pp.39-46
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• 2009

In this study, behavior of a rigid continuous wall, earth pressure distribution with construction stage, and axial force of earth anchors were evaluated based on field monitoring data and numerical analysis results. For this purpose, a construction site excavated using the diaphragm wall was selected and full instrumentation system was introduced. From monitoring results, it was found that the values of horizontal displacement of the wall measured from the inclinometers, which were installed within the diaphragm wall were similar to analytical value. The earth pressure increased with excavation progress due to jacking force of the ground anchors installed in previous excavation stages. When the excavation depth reached 60% of the final depth, observed earth pressure distribution was similar to that estimated from Peck's apparent earth pressure distribution. When the excavation depth was around 90% of the final depth, values of observed earth pressure showed middle values between those of Peck's and Tschebotarioffs apparent earth pressures. It was also observed that, when excavation depth is deep, values of the earth pressures from the rigid wall were similar to those estimated from conventional earth pressure distribution shape proposed for flexible walls.

• Korean Journal of Human Ecology
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• v.12 no.5
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• pp.767-776
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• 2003

The purpose of this study was to classify side somatotypes of the trunk by analysing photographic data. Then their distribution according to the age groups was studied. The subjects were 315 females of 18 to 49 year-old. Thirty one photographic measurements were taken to each subject. The factors affecting the side somatotype of the trunk were obtained by principal component analysis, vertical size, posterior/anterior depth and neck posture. The side somatotypes of the trunk were classified into 4 types and their differences were shown by analysing photographic data. The side silhouettes of 4 types were compared with balanced type. By suggesting the canonical discriminant function with the unstandardized canonical coefficient, individual somatotype of the trunk could be discriminated from the photographic data of anterior neck height, anterior waist height, posterior waist depth, buttock height, and anterior depth at the level of back protrusion. The frequency distribution of the side somatotypes of the trunk according to the age groups could be applied for clothing construction and the rate of clothing production.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.447-450
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• 2007

Trap effects on the formation of space-charge field (SCF) associated with the photorefractivity of nonlinear optical polymers were studied by the Monte Carlo simulation using modified Gaussian disorder model. The charge transport dynamics influenced by the presence of trap molecules controls the formation of SCF via the charge distribution. Temporal behavior of SCF formation and SCF dependence on the trap depth are discussed in terms of the concentration and distribution of charges (holes and ionized acceptors) developed following illumination of light. The correlation of the trap depth and the energetic disorder is presented for an optimal efficiency for the SCF formation.

• Nuclear Engineering and Technology
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• v.7 no.4
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• pp.285-293
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• 1975

A result of the study to determine the depth-dose distribution along the central axis of a polyethylene sphere in diameter of 30cm is described. Depth-dose distribution in the polyethylene sphere for broad beam of monoenergetic photons has been experimentally determined with thermoluminescent dosimeter as a cavity dosimeter. The conversion of dose absorbed in the LiF TLD to dose in the surrounding medium was carried out on the basis of Burlin's generalized cavity theory. Presented in graphical forms are the results obtained. The maximum absorbed doses in the sphere were observed at the depth of about 0.3cm and 0.5cm from the surface of the sphere for the gamma-rays of $^{137}$ Cs and $^{60}$ Co, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.