• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.61-69
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• 2017

The study on interference channel is very important information theoretically and many studies have been done on it. However, even in the simplest case, even in the case of two user interfering channels, the channel capacity is not yet known except in special cases. Recently, research on the multiplexing gain that shows the tendency of the transmission rate in the high signal to noise ratio (SNR) band has been actively carried out, instead of accurately grasping the channel capacity. Obtaining optimal multiplexing gain can reveal trends in channel capacity at high signal-to-noise ratio bands. In an interfering channel with two users, the best multiplexing gain can be obtained by eliminating the interference. However, recent research shows that when the number of users is more than three, the optimal multiplexing gain can not be obtained only by zero forcing and a new technique called interference sorting is needed. There are two types of interference sorting techniques. Beamforming A method of effectively separating signals and interference by properly selecting matrices and constructing structured codes using rational numbers and irrational numbers. The interference alignment technique can achieve optimal multiplexing gain in various environments such as interference channel, X channel, compound broadcast channel, and multi hop network for multi source multi destination. In recent years, it has also been applied to distributed storage. Lee et al., "Lattice Code Interference Alignment in Cooperative Multipoint Transmission (COMP) for Interference Channels of Three Users", Journal of the Institute of Electronics Engineers, vol.49-TC,no.6,2012. In this paper, the DoF of delayed channel information is obtained.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.801-808
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• 2023

In order to minimize radiation exposure and secure diagnostic value images during CT examination of the head of children, the usefulness of volume axial mode is evaluated through comparison and analysis of exposure dose and images of volume axial mode, high pitch mode, and helical mode. Image evaluation and dose evaluation were performed in CT high pitch mode, helical mode, and volume axial mode for infants under the age of 1 according to the voltages of 70, 80, and 100 kVp tubes. The image evaluation was conducted by comparing image quality by setting ROI for each image, calculating SNR and CNR, using ONE-WAY (ANOVA) to evaluated statistical significance, and cross-examining the dose evaluation using DLP values displayed in the Dose Report. When inspected using volume axial mode, DLP values were generally low, and SNR and CNR values differed by ROI and kVp. When volume axial mode evaluated the quality of the image compared to other scan modes, the difference is not uniform. For the reason, certain modes are not considered excellent, but the exposure dose was reduced the most in terms of dose. In addition, the point that the volume axial mode can be examined at its original location, short scanning time and needless of table movement is useful for CT tests for children under 1 year of age with high radiation sensitivity.

• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.20-31
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• 2005

Three dimensional Monte-Carlo simulations of non-ergodic transport of a lion-reactive solute plume by steady-state groundwater flow under a uniform mean velocity in isotropic heterogeneous aquifers were conducted. The log-normally distributed hydraulic conductivity, K(x), is modeled as a random field. Significant efforts are made to reduce tile simulation uncertainties. Ensemble averages of the second spatial moments of the plume and plume centroid variances were simulated with 1600 Monte Carlo runs for three variances of log K, ${\sigma}_Y^2=0.09,\;0.23$, and 0.46, and three dimensionless lengths of line plume sources normal to the mean velocity. The simulated second spatial moment and the plume centroid variance in longitudinal direction fit well to the first order theoretical results while the simulated transverse moments are generally larger than the first order results. The first order theoretical results significantly underestimated the simulated dimensionless transverse moments for the aquifers of large ${\sigma}_Y^2$ and large dimensionless time. The ergodic condition for the second spatial moments is far from reaching in all cases simulated, and transport In transverse directions may reach ergodic condition much slower than that in longitudinal direction. The evolution of the contaminant transported in a heterogeneous aquifer is not affected by the shape of the initial plume but affected mainly by the degree of the heterogeneity and the size of the initial plume.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.345-351
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• 1996

Studies on extraction and color characteristics of purple sweet potato (PSP) pigment were performed to provide the basic information for the utilization of PSP as a new source of natural food colorant. PSP pigment was extracted well with the polar solvents such as distilled water, ethanol, and methanol. but hardly extracted with the non-polar solvents. Among the tested solvents, 20% ethanol solution containing 0.1% citric acid was found to be the most efficient for extraction of the pigment from PSP. PSP contained high amount of pigment not only in the epidermis but also in the flesh of the potato. The PSP pigment was heat stable even under pretreatments such as autoclaving and blanching of the potato before extraction. The optimum temperature of the extraction for the PSP Pigment was decided to be $30^{\circ}C$ by considering the stability and the rate of extraction. The pigment was markedly influenced by the change of pH. The color of the pigment solution was red at the pH range of $1.0{\sim}3.0$, became blue at $7.0{\sim}8.0$, then turned green at $9.0{\sim}10.0$. A characteristic batho-chromic shift of the pigment solution was observed as the pH of the solution increased.

• Journal of Wetlands Research
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• v.7 no.2
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• pp.105-120
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• 2005

This study was carried out at Reed Marsh of Sihwa Lake from July 2003 to June 2004. We observed total(sum of maximum population) 5,752 individuals of 70 species including 12 species of ducks, 10 species of egrets, 6 species of wagtails and buntings, 4 species of eagles. The most dominant species was Spotbill Duck(Anas poecilorhyncha - 3,518 individuals, 61.16%), and other species were Mallard(Anas platyrhynchos - 540 individuals, 9.39%), Great Reed-Warbler(Acrocephalus arundinaceus - 217 individuals, 3.77%). Reed Marsh of Sihwa Lake were observed many kinds of protected species such as Great Bittern(Botaurus stellaris), Mandarin Duck(Aix galericulata), Chinese Sparrow Hawk (Accipiter soloensis), Eurasian Sparrow Hawk(Accipiter nisus), Japanese Buzzard(Buteo buteo), Hen Harrier(Circus cyaneus), Eurasian Hobby(Falco subbuteo), and Common Kestrel(Falco tinnunculus). Since the Reed Marsh of Sihwa Lake arrived many individuals of waterbird, crop damage by the waterbird occurred in the surrounding rice fields. It was an area adjacent to the reed marsh of sihwa lake such as Yoopori and Samhwari Bibongmyoun, Yamokri Maesongmyoun Hwaseong City. Bird of crop damage was ducks openly. The most species was Spot-billed Duck. Crop damage types by the Spot-billed Duck were grazing, used the grain up or lower in quality with step on the rice. Crop damage size was about 560bags of rice during the one month on August 2002. In 2003, After carrying out the various crop damage reduction countermeasures, which measured crop damage size in 2002's crop damage area. It happened about 152bags of rice during the two months from on August to September 2003. Migration routes of Spot-billed Duck were that it was migrated from up the sihwa lake to reed marsh. It took a rest at reed marsh and migrated the surrounding rice fields for the feeding action. In 2002, it was migrated direct from up the sihwa lake to in surrounding rice fields. But as environment of reed marsh was improved better than 2002, it was migrated to reed marsh because of reducing the energy attrition rate. Crop damage reduction countermeasures are get on ears to use explosion machine, searchlight, start-gun and patrol at regular intervals. Which was an effect short term. Indirect method is to make a feeding area of substitution at up the sihwa lake and reed marsh of sihwa lake.

• Journal of Soil and Groundwater Environment
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• v.13 no.4
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• pp.8-21
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• 2008

A series of three-dimensional numerical simulations using a hydrodynamic dispersion numerical model is performed to analyze quantitatively impacts of layered heterogeneity of geologic media and groundwater pumping schemes on groundwater flow and salt transport in coastal aquifer systems. A two-layer heterogeneous coastal aquifer system composed of a lower sand layer (aquifer) and an upper clay layer (aquitard) and a corresponding single-layer homogeneous coastal aquifer system composed of an equivalent lumped material are simulated to evaluate impacts of layered heterogeneity on seawater intrusion. In addition, a continuous groundwater pumping scheme and two different periodical groundwater pumping schemes, which withdraw the same amount of groundwater during the total simulation time, are applied to the above two coastal aquifer systems to evaluate impacts of groundwater pumping schemes on seawater intrusion. The results of the numerical simulations show that the periodical groundwater pumping schemes have more significant adverse influences on groundwater flow and salt transport not only in the lower sand layer but also in the upper clay layer, and groundwater salinization becomes more intensified spatially and temporally as the pumping intensity is higher under the periodical groundwater pumping schemes. These imply that the continuous groundwater pumping scheme may be more suitable to minimize groundwater salinization due to seawater intrusion. The results of the numerical simulations also show that groundwater salinization in the upper clay layer occurs significantly different from that in the lower sand layer under the periodical groundwater pumping schemes. Such differences in groundwater salinization between the two adjacent layers may result from layered heterogeneity of the layered coastal aquifer system.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.695-708
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• 2008

In order to evaluate the geochemical behaviors of elements with waste rocks in the abandoned Jangpoong Cu mine area, total concentration analysis and leaching experiments were performed. The content of elements within waste rocks compared with background values decreased in order of As>>Cu>Pb>Cd>Co. Leaching experiments were carried out at various extraction environments, considering the acid rain ($0.00001{\sim}0.001N\;HNO_3$) and the acid mine drainage ($0.001{\sim}0.1N$ HNO3). After 24 hours of reaction with different acidic solution, the leaching characteristics of waste rocks were classified into three types according to final pH of leaching solution. Type I refers to the case that the final pH of leaching solution was lower than that of the reaction solution due to the dissolution of acidic minerals from rocks, while type 2 and 3 refer to the case that the final pH maintained higher than that of the reaction solution. Theses types include in acid buffering minerals such as clay minerals and carbonate minerals. The leaching characteristics of the elements after the reaction could be categorized into As-Co-Fe, Cu-Mn-Cd-Zn, and Pb. As-Co-Fe started to get leached under 2.5 of pH regardless of changes in the final pH, and Cu-Mn-Cd-Zn showed different initial leaching pH according to the types of final pH changes. Based on the pH value where leaching started regardless of leaching concentration, the relative mobility of each element was in the order of Mn Zn>Cd>Cu>>Fe Co>As>Pb. Thus, more higher mobility elements(Zn, Mn and Cu) were leached by reacting with acid rain water. Acid mine drainage may result in distributions of elements having relatively less mobility(As, Fe, Co and Pb).

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.211-230
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• 2016

Detailed mapping along the Keumwang fault reveals a complex history of multiple brittle reactivations following late Jurassic and early Cretaceous ductile shearing. The fault core consists of a 10~50 m thick fault gouge layer bounded by a 30~100 m thick damaged zone. The Pre-cambrian gneiss and Jurassic granite underwent at least six distinct stages of fault movements based on deformation environment, time and mechanism. Each stage characterized by fault kinematics and dynamics at different deformation environment. Stage 1 generated mylonite series along the Keumwang shear zone by sinistral ductile shearing during late Jurassic and early Cretaceous. Stage 2 was a mostly brittle event generating cataclasite series superimposed on the mylonite series of the Keumwang shear zone. The roundness of pophyroclastes and the amount of matrix increase from host rocks to ultracataclasite indicating stronger cataclastic flow toward the fault core. At stage 3, fault gouge layer superimposed on the cataclasite generated during stage 2 and the sedimentary basins (Umsung and Pungam) formed along the fault by sinistral strike-slip movement. Fragments of older cataclasite suspended in the fault gouge suggest extensive reworking of fault rocks at brittle deformation environments. At stage 4, systematic en-echelon folds, joints and faults were formed in the sedimentary basins by sinistral strike-slip reactivation of the Keumwang fault. Most of the shearing is accommodated by slip along foliations and on discrete shear surfaces, while shear deformation tends to be relatively uniformly distributed within the fault damage zone developed in the mudrocks in the sedimentary basins. Fine-grained andesitic rocks intruded during stage 4. Stage 5 dextral strike-slip activity produced shear planes and bands in the andesitic rocks. ESR(Electron Spin Resonance) dates of fault gouge show temporal clustering within active period and migrating along the strike of the Keumwang fault during the stage 6 at the Quaternary period.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.150-156
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• 2009

Objectives : The conventional removable appliance, composed of wires and acrylic resin, had unaesthetic results and poor retention. The flexible denture, as an alternative, presents improved aesthetics with the thin and strong resin retentive area. In addition, it also enhances patients' sensory function as a result of decreased volume of denture base. The flexibility of the flexible denture reduces the possibility of fracture and distributes the masticatory forces transmitted to the abutments and residual bone tissue. This report describes a 10-year-old girl and a 6-year-old boy with oligodontia treated with the flexible dentures as an alternative to conventional removable appliances. Methods : Impression was taken using alginate material and sent to a laboratory with the bite for fabrication of the flexible denture. Prior to try-in, the flexible denture was immersed in water at $90^{\circ}C$ for one minute and cooled. Impinging area of the denture was checked by $Fit-Checker^{(R)}$ and removed and the denture was delivered to the patient. Results : Both patients were satisfied with the flexible dentures, which presented improved retention and aesthetics. Conclusion : For patients with oligodontia, flexible dentures can be considered as a treatment of choice, which may replace the conventional denture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4945-4953
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• 2010

The purpose of this study was to analyze the differences in perception levels of goals and concepts of physical education by the body image and gender of middle school students. Among 461 middle students randomly selected by a multistaged cluster sampling technique, 433 students(boys 267, girls 166) filled out questionnaires consisted of Figure Rating Scale and modified ones. To know the differences in the perception levels of goal and concept of physical education by sex, t-test was utilized. In order to find out the differences in the perception levels of goal and concept of physical education by body image, ANOVA was performed using the SPSS Windows 12.0. The results of this study revealed that boys had higher level of goal and concept of physical education than girls. Second, middle school students classified into normal body image was higher level of goal and concept of physical education that other body images such as very thin, thin, very obese, and obese ones. The results of this study indicated that curriculum of physical education focused on fragmentation of health, psychomotor, cognitive, affective, leisure, holistic human should make girls understand thoroughly and deeply goals and concepts of physical education and ideal body image.