• Journal of radiological science and technology
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• v.42 no.6
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.43-52
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• 2010

The geochemical and nitrogen isotopic analyses for shallow groundwater of Ogcheon area were carried out to characterize the geochemical characteristics of the groundwater and to identify the source of nitrate. Groundwater shows a neutral pH to weakly alkalic condition with pH values ranging from 6.9 to 8.4. The average of EC, Eh and DO is $344.2\;{\mu}s/cm$, 195 mV, 4 mg/L, respectively. According to piper diagram, chemical composition of groundwater is dominantly characterized by Ca-$HCO_3$ type. On the other hand, groundwater type in the study area include Ca-Cl+$NO_3$ type that were highly influenced by agricultural activities. $NO_3$-N concentration of the collected samples(n=45) range from 12.4 to 34.2 mg/l. These data show that the $NO_3$-N concentration exceeds Korea Drinking Water Standard (10 mg/l). The $\delta^{15}N-NO_3$ values range from $2.7^{\circ}/_{\circ\circ}$ to $18.8^{\circ}/_{\circ\circ}$. The enrichments of heavy isotope in the groundwater indicate that major origin of nitrate pollution were associated with animal and human waste. Also the denitrification may have partly contributed as one of the sources of nitrogen.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.985-993
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• 1997

The effects of CaO and MgO fluxes on the fusibility of fly-ashes were investigated for two different fly-ashes. A fusion temperature of mixtures of selected fly-ashes and fluxes were measured by the ASTM test method(D1857) and the differential thermal analysis. IDT of these samples added CaO and MgO as a fluxing agent dropped in the range of 114 to $294^{\circ}C$ and 80 to $224^{\circ}C$, respectively. Compared with ash fusion temperature to Base/Acid ratio, the lowest ash fusion temperature were measured in the range of 0.7 to 0.8 for CaO-fly ash mixtures and 0.3 to 0.4 for MgO-fly ash mixtures. As a result, MgO in small addition acted as a more effective flux than CaO. A conventional Base/Acid ratio and liquidus point of ternary diagram did not show a good correlation with ash fusion temperature for these samples. In pure fusion temperature of fly ash-mixtures, DTA was better method than ASTM test method.

• Journal of the Korean Geotechnical Society
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• v.31 no.9
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• pp.69-78
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• 2015

If an active displacement occurs on a wall with finite size, the ground behind the wall forms shapes of 3-dimensional wedges and 3-dimensional active earth pressure are applied on the wall. In the previous studies, shapes of 3-dimensional wedges were measured and the resultant of 3-dimensional active earth pressure has been calculated. In this study, the magnitude and the distribution of 3-dimensional active earth pressure depending on the size of a rectangular wall, which was defined by the aspect ratio (h/w), that is, the ratio between the height and the width of wall, were measured and compared with previous 3-dimensional models. The result shows that, the horizontal displacement (S) of the wall is approx 0.12% of the height of wall (h). The resultant 3-dimensional active earth pressure is similar to that of Karstedt (1982). The distributions of earth pressures on the wall are parabolic shape. The peak earth pressure was measured at the 0.5~0.55 depth from the ground surface. The reduction factor of 3-dimensional active earth pressure against the 2-dimensional earth pressure (${\alpha}$) depending the aspect ratio (h/w) is presented by the diagram.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.3
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• pp.35-51
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• 2015

The purpose of this study is to improve the previous groundwater contamination vulnerability assessment method, apply it to the study area, and select priority areas for groundwater management based on the quantitative analysis of groundwater contamination vulnerability. For this purpose, first, the previous 'potential contamination' based on groundwater contamination vulnerability assessment method was upgraded to the methodology considering 'adaptation capacity' which reduced contamination. Second, the weight of groundwater contamination vulnerability assessment factors was calculated based on the analytical hierarchy process(AHP) and the result of survey targeting groundwater experts. Third, Gyeonggi-do was selected as the study area and the improved methodology and weight were implemented with GIS and actual groundwater contamination vulnerability assessment was carried out. Fourth, the priority area for groundwater contamination management was selected based on the quantitative groundwater contamination vulnerability assessment diagram. The improved detailed groundwater contamination vulnerability assessment factors in this study were a total of 15 factors, and 15 factors were analyzed as new and improved weight with higher 'adaptation capacity' than the assessment factor corresponding to the previous 'potential contamination' in the weight calculation result using AHP. Also, the result of groundwater contamination vulnerability assessment in Gyeonggi Province using GIS showed that Goyang and Gwangmyeong which were adjacent to Seoul had a high groundwater contamination vulnerability and Pocheon and Yangpyeong County had a relatively low groundwater contamination vulnerability. In this study, the previous groundwater contamination vulnerability assessment was improved and applied to study areas actually. The result of this study can be utilized both directly and indirectly for the groundwater management master plan at national and local government level in the future.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.97-106
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• 2002

In 3GPP2 standard, MIP is used and a PDSN performs the function of FA to support macro mobility. When a MS is roaming from a PDSN area to another, the mobility supported is called macro mobility, while it is called micro mobility when a MS is roaming from a RN area to another in a PDSN area. Since a PDSN performs the function of FA in 3GPP2 standard, it is possible to support mobility but its mechanism is actually for supporting macro mobility, not for micro mobility, thus it is weak in processing fast and seamless handoff to support micro mobility. In this paper, we suggest the seamless handoff algorithm barred on multicast group mechanism to support micro mobility. Depending on the moving direction and velocity of a MS, the suggested algorithm constructs a multicast group of RNs on the forecasted MS's moving path, and maximally delays RNs'joining to a multicast group to increase the network efficiency. Moreover, to resolve the buffer overhead problem of the existent multicast scheme, the algorithm suggests that each RN buffers data only after the forecasted handoff time. To prove deadlock freeness and liveness of the algorithm. we use state transition diagrams, a Petri-net modeling and its reachability tree. Then, we evaluate the performance by simulation.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.217-217
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• 2019

해안과 하천이 위치해 있는 낙동강하구의 담 염수 경계면 추적 연구에서 담 염수 경계면의 담수기원특성을 분석하기 위해서는 담 염수 경계면을 이루는 담수의 기원이 하천 혹은 지하수 인지를 규명하는 것이 매우 중요하다. 담 염수 경계면에 있는 담수는 일반적으로 하천과 지하수에 의한 것으로, 낙동강하구 일원을 대상으로 지하수공 내 해수침투 여부 파악을 위해 화학적(유기물) 분석을 실시하였다. 이와 아울러 낙동강하구 일원에서 담 염수 경계면에서 채취한 수질시료의 담수기원을 분석하기 위하여 K-water연구원 수질안전센터에 지하수공 7개지점(BH-1~7호공)의 심도별 물시료 2~4개지점(총 23개 지점), 하천(1개 지점), 해수 및 해안유출수(각 1개 지점)를 포함한 26개 시료를 LC-OCD(Liquid Chromatography-Organic Carbon Detector)로 분석하였다. LC-OCD 분석결과 특성은 기본적으로 유기물질이 물에서 유래한 aquagenic 혹은 토양층에서 유래한 pedogenic 유기물질 인지에 달려있다. 댐 또는 하천에서 pedogenic 유기물의 농도는 일반적으로 유역분지의 수문 또는 수리지질학적 경로에 의존한다. pedogenic 유기물들은 주로 상대적으로 작은 분자량을 갖는 친수성, 높은 사슬밀도 및 내화성 분자특성을 갖는 펄빅산으로 구성된다. aquagenic 유기물질은 수생 식물성 생물이나 플랑크톤의 분해 산물로서 세포벽에서 유래된 peptidoglycans와 고분자량의 polysaccharides 등을 포함한다(Chio & Jung, 2008; Buffle, 1988). 담 염수 경계면 추적을 위한 7개 관측공의 심도별 수질시료는 하천, 해수, 그리고 해안유출수의 용존유기탄소를 분석하기 위하여 LC-OCD로 정밀분석하였다. 그 결과, humic, 휴믹물질의 산화물질인 building blocks, 생물고분자 물질(bio-polymers), neutrals, acids로 분석되었으며, 일반적인 자연유기물질의 기원은 pedogenic과 aquagenic 유기물질로 분류된다. IHSS 표준물질 분석 등을 통한 SUVA 값으로부터 자연유기물질의 기원정보를 제공하는 HS-Diagram으로 도시한 결과, 2018년 11월 2일 조사한 26개의 원수시료 전체는 pedogenic fulvic acid〉aquagenic fulvic acid으로 하천의 기원이 우세한 것으로 분석되었다. BH-1호공과 BH-6호공의 특정 1개구간 GL.-6m를 제외한 모든 구간에서 aquagenic FA의 지하수 기원으로 분석되었으며, 나머지 지하수공(BH-2, 3, 4, 5, 7)과 하천 및 해안유출수는 유역분지 수문학적 경로인 pedogenic FA의 하천 기원의 담수인 것으로 분석된다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.261-273
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• 2019

Recently, with the development of IT technology, there is an increasing interest in cloud services as the number of users using mobile devices such as mobile phones and tablets is increasing. However, there is a need for techniques to control or control various methods of accessing data as the user's service demands increase. In this paper, we propose a dual key based user authentication model that improves the user 's authentication efficiency by using two keys (secret key and access control key) to access the users accessing various services provided in the cloud environment. In the proposed model, the operation process and the function are divided through the sequence diagram of the algorithms (key generation, user authentication, permission class permission, etc.) for controlling the access right of the user with dual keys. In the proposed model, two keys are used for user authentication and service authorization class to solve various security problems in the cloud service. In particular, the proposed model is one of the most important features in that the algorithm responsible for access control of the user determines the service class of the user according to the authority, thereby shortening the management process so that the cloud administrator can manage the service access permission information of the user.

• Composites Research
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• v.34 no.3
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• pp.155-160
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• 2021

Metamaterials are complexes of elements that can create properties not found in naturally occurring materials, such as changing the direction of forces, creating negative stiffness, or altering vibration and impact properties. In the case of wood pile metamaterials that are easy to manufacture and have excellent performance in reducing vibration and shock in the vertical direction, basic research on variables affecting shock transmission is needed to reduce shock. Although research on impact reduction according to geometrical factors is being conducted recently, studies on the effect of material variables on impact reduction are insufficient. In this paper, finite element analysis was carried out by variablizing the geometrical properties (lamination angle, diameter, length) and material properties (modulus of elasticity, specific gravity, Poisson's ratio) of wood pile cylinders. Through finite element analysis, the shape of the wooden pile cylinder delivering impact was confirmed, and the effect of each variable on the reduction of impact force and energy was considered through main effect diagram analysis, and frequency band analysis was performed through fast Fourier transform. proceeded In order to reduce the impact force and vibration, it was found that the variables affecting the contact area of t he cylinder have a significant effect.

• Economic and Environmental Geology
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• v.50 no.5
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• pp.325-340
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• 2017

The Seongdo Pb-Zn deposit, located in the northwestern part of the Ogcheon Metamorphic Belt, consists of skarn ore replacing limestone within the Hwajeonri Formation of Ogcheon Group and hydrothermal vein ore filling the fracture of host rock. Skarn minerals comprise mostly hedenbergitic pyroxene, garnet displaying oscillatory zonal texture composed of grossular and andradite, and a small amount of wollastonite, tremolite, and epidote, indicating reducing condition of formation. Ore minerals of skarn ore include sphalerite and galena with a small amount of pyrite, pyrrhotite, and chalcopyrite. In hydrothermal vein ore, arsenopyrite, sphalerite, chalcopyrite, and pyrite occur with a small amount of galena, native Bi, and stannite. Chemical compositions of sphalerite vary from 17.4 mole% FeS in average for dark grey sphalerite, 3.6 mole% for reddish brown sphalerite in skarn ore, and to 10.3 mole% FeS in hydrothermal vein ore. In comparison with representative metallic deposits in South Korea on the FeS-MnS-CdS diagram, skarn and hydrothermal vein ore plot close to the field of Pb-Zn deposits and Au-Ag deposits, respectively. Arsenic contents of arsenopyrite in hydrothermal vein ore decrease from 31.93~33.00 at.% in early stage to 29.58~30.21 at.% in middle stage, and their corresponding mineralizing temperature and sulfur fugacity are $441{\sim}490^{\circ}C$, $10^{-6}{\sim}10^{-4.5}atm$. and $330{\sim}364^{\circ}C$, <$10^{-8}atm$. respectively. Phase equilibrium temperatures calculated from Fe and Zn contents for coexisting sphalerite and stannite in hydrothermal vein are $236{\sim}254^{\circ}C$. Sulfur isotope compositions are 5.4~7.2‰ for skarn ore and 5.4~8.4‰ for hydrothermal vein ore, being similar or slightly higher to magmatic sulfur, suggesting that ore sulfur was mostly of magmatic origin with partial derivation from host rocks. However, much higher sulfur isotope equilibrium temperatures of $549^{\circ}C$와 $487^{\circ}C$, respectively for skarn ore and hydrothermal ore, than those estimated from phase equilibria imply that isotopic equilibrium has not been fully established.