• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.905-917
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• 2008

Road or Railway construction over soft ground is needed to be considered on secondary consolidation which will be caused differential settlement, lack of transport serviceability, higher maintenance cost. Especially for the railway construction in the second phase of Gyung-Bu or Ho-Nam high speed railway, concrete slab track has been adapted as a safe and cost effective geotechnical solution. In this case controlling the total settlement under the tolerance is essential. And pile supported geogrid reinforced construction method is suggested as a solution for the problem of the traditional method on soft soil treatments. Pile supported geogrid reinforced construction method consists of piles that are designed to transfer the load of the embankment through the compressible soil layer to a firm foundation. The load from the embankment must be effectively transferred to the piles to prevent punching of the piles through the embankment fill creating differential settlement at the surface of the embankment. The arrangement of the piles can create soil arching to carry the load of embankment to the piles. In order to minimize the number of piles geogrid reinforced pile supported construction method is being used on a regular basis. This method consists of one or more layers of geogrid reinforcement placed between the top of the piles and the bottom of the embankment. This paper presents several methods of pile supported geogrid reinforced construction and calculation results from the several methods and comparison of them.

• 한국기후변화학회지
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• 제7권3호
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• pp.357-371
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• 2016

Buildings in the city acts as a cause of distorted wind direction, wind speed, causing the stagnation of the air flow. In the recent trend of climate change can not but consider the temperature rise of the urbanization. This study was aimed to analyze the thermal comfort of planetary boundary layer in different artificial constructions areas which has a direct impact on urban climate, and estimating the warming phenomena. Envi-met model was used to consider the urban structure associated with urban growth in order to precisely determine the impact of the building on the city weather condition. The analyzed values of thermal comfort index were temperature, wind speed, horizontal and vertical turbulent diffusivity. In particular, analysis of the PPD(Predicted Percentage of Dissatisfied) represents the human thermal comfort. In this study, by adjusting the arrangement and proportion of the top floor building in the urban it was found that the inflow of the fresh air and cooling can be derived low PPD. Vertical heat flux amount of the city caused by climate change was a factor to form a high potential temperature in the city and the accumulation of cold air does not appear near the surface. Based on this, to make the city effectively respond to climate change may require a long-term restructuring of urban spatial structure and density management.

• 한국의상디자인학회지
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• 제24권1호
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• pp.35-43
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• 2022

This study aims to analyze the physical properties of non-woven fabric sheets, which continue to grow in the cosmetic market. Non-woven fabric sheets were used as specimens, and a total of 17 samples were analyzed. To evaluate the physical properties of the non-woven fabric sheet, the weight, tensile strength, surface properties, free swell absorption, and wet stiffness were tested. Through the results itw was determined that non-woven fabric sheets for mask packs should be manufactured considering fiber arrangement so that the weight is 40 g/m², and the tensile strength should be maintained near 12 kgf. In addition, it was confirmed that the material selection and process conditions should be adjusted so that the free swell absorption is at least 8 g/g, and the wet stiffness is 200 mg. Therefore, since the non-woven fabrics for the mask sheets can be used in various products depending on fabric composition, this study will be expected to be basic data for the continuous growth of the sheet-type mask packs coming to market.

• 한국동물위생학회지
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• 제44권4호
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• pp.299-303
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• 2021

A captive male polar bear (Ursus maritimus) was found dead after a long-term anorexia at a Park Zoo in Republic of Korea. At necropsy, the liver lesion was prominent with hepatomegaly carrying a big mass and numerous small nodules in various sizes. The cut surface of the nodules was creamy white, firm, and solid with umbilicated appearance. Histologically, there was proliferation of hepatocellular neoplastic cells arranged in glandular-like (pseudoglandular) pattern and complete loss of hepatocellular arrangement. The immunoreactivity for neoplastic hepatocyte antigens was positive for hepatocyte paraffin 1, and negative for vimentin, cytokeratin 7 and 19, and carcinoembryonic antigen. Based on those diagnostic features, the neoplasia was diagnosed as hepatocellular carcinoma. To the author's knowledge, this is the first case report of hepatocellular carcinoma in the captive polar bear in Republic of Korea.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.38-43
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• 2021

Permanent magnet linear synchronous motor (PMLSM) is suitable for use in cleanroom environments and have advantages such as high speed, high thrust, and high precision. If the stators are arranged in the entire moving path of the mover, there is a problem in that the installation cost increases. To solve this problem, discontinuous armature arrangement PMLSM has been proposed. In this case, the mover receives a greater detent force in the section where the stator is not arranged. When a large detent force occurs, it appears as a ripple component of the thrust during PMLSM operation. If the shape of the stator is changed to reduce the detent force, the characteristics of the back EMF are changed. Therefore, in this paper, the detent force and the harmonic components of back EMF were reduced through multi-purpose shape optimization. To this end, the FEA model was constructed and main effect analysis was performed on the major shape variables affecting each objective function. Then, the optimal shape that minimizes the objective function was derived through the response surface analysis method.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.125-129
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• 2022

The current display technology tends to be highly integrated with high resolution, the element size is gradually downsized, and the structure becomes complicated. Inductively coupled plasma (ICP) dry etcher of various types of etching equipment is a structure that places a large multi-divisional antenna source on the top lid, passes current to the Antenna, and generates plasma using the induced magnetic field generated at this time. However, in the case of a device of a large area size, a support that can withstand a load structurally is necessary, and when these support portions are applied, arrangement of antenna becomes difficult, which causes reduction in uniformity. As described above, the development of antenna source of a large area having a uniform plasma density on the whole surface is difficult to restrict hardware (H/W). As a solution to this problem, we confirmed the change in uniformity of plasma by applying two kinds of specific shape faraday shield(FICP) to the lower part of the large area upper lid antenna of 6 and 8th more than that generation size. In this thesis, we verify the faraday shield effect which can improve plasma uniformity control of ICP dry etcher equipment applied to medium and large displays.

• 마이크로전자및패키징학회지
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• 제28권4호
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• pp.97-101
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• 2021

본 연구에서는 실험 설계법을 통해 인터포저에서 Through Silicon Via (TSV) 및 Redistributed Layer (RDL)의 구조적 변형에 따른 삽입 손실 특성 변화를 확인하였다. 이때 3-요인으로 TSV depth, TSV diameter, RDL width를 선정하여, 구조적 변형을 일으켰을 때 400 MHz~20 GHz에서의 삽입 손실을 EM (Electromagnetic) tool Ansys HFSS(High Frequency Simulation Software)를 통해 확인하였다. 반응 표면법을 고려하였다. 그 결과 주파수가 높아질수록 RDL width의 영향이 감소하고 TSV depth와 TSV diameter의 영향이 증가하는 것을 확인했다. 또한 분석 범위 내에서 RDL width를 증가시키면서 TSV depth를 감소시키고 TSV diameter를 약 10.7 ㎛ 고정하는 것이 삽입 손실을 가장 최적화 시키는 결과가 관찰되었다.

• Corrosion Science and Technology
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• 제22권4호
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• pp.273-286
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• 2023

Rebar is embedded in concrete to create reinforced concrete (RC). Rebar carries most of the tensile stress and gives compressively loaded concrete fracture resistance. However, embedded steel corrosion is a significant cause of concern for RC composite structures worldwide. It is one of the biggest threats to concrete structures' longevity. Due to environmental factors, concrete decays and reinforced concrete buildings fail. The type and surface arrangement of the rebar, the cement used in the mortar, the dosing frequency of the concrete, its penetrability, gaps and cracks, humidity, and, most importantly, pollutants and aggressive species all affect rebar corrosion. Either carbonation or chlorides typically cause steel corrosion in concrete. Carbonation occurs when carbon dioxide in the atmosphere combines with calcium within the concrete. This indicates that the pH of the medium is falling, and the steel rebar is corroding. When chlorides pass through concrete to steel, corrosion rates skyrocket. Consideration must be given to concrete moisture. Owing to its excellent resistance, dry concrete has a low steel corrosion rate, whereas extremely wet concrete has a low rate owing to delayed O₂ transfer to steel surfaces. This paper examines rebar corrosion causes and mechanisms and describes corrosion evaluation and mitigation methods.

• 대한심미치과학회지
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• 제31권1호
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• pp.19-25
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• 2022

심미에 대한 환자의 기대와 요구는 다양하고 복잡하다. 때로는 원하는 것이 명확하지 못할 때고 있고 다다르기에는 한계가 있는 경우도 자주 만나게 된다. 환자의 주소를 객관적인 요소로 분석해야하는 진료자의 입장에서는 환자의 표현을 요구와 필요(wants and needs)에 기반하여 해석해야하는 숙제를 않고 가게 된다. 환자의 요구와 필요를 기반으로 하여 치료의 계획에 있어서 심미적 개선 방향을 설정하고 이를 피드백을 통해 검증하여 소통하는 것이 필요하다. 심미(esthetics)란 객관적인 기준을 기반으로 하지만 일상의 임상에 있어서 환자 개개인의 주관적인 기준을 잘 반영하여야 만족스런 결과로 한발자국 다가서는 슬기로운 접근이라 하겠다. 건강한 자연치를 기준으로하면 한계성을 가지고 있는 중년 환자의 증례를 통해 심미적 분석(analysis)과 접근 전략(strategies)에 대해 함께 살펴보고자 한다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제26권3호
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• pp.167-202
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• 2023

A central problem of mathematics teaching worldwide is probably the insufficient adaptive handling of tasks-especially in computational practice phases and modeling tasks. All students in a classroom must often work on the same tasks. In the process, the high-achieving students are often underchallenged, and the low-achieving ones are overchallenged. This publication uses different modeling of the tennis serve as an example to show a possible solution to the problem and develops and discusses one adaptive task each for middle school, high school, and college using three mathematical models of the tennis serve each time. From model to model within the task, the complexity of the modeling increases, the mathematical or physical demands on the students increase, and the new modeling leads to more realistic results. The proposed models offer the possibility to address heterogeneous learning groups by their arrangement in the surface structure of the so-called parallel adaptive task and to stimulate adaptive mathematics teaching on the instructional topic of mathematical modeling. Models A through C are suitable for middle school instruction, models C through E for high school, and models E through G for college. The models are classified in the specific modeling cycle and its extension by a digital tool model, and individual modeling steps are explained. The advantages of the presented models regarding teaching and learning mathematical modeling are elaborated. In addition, we report our first teaching experiences with the developed parallel adaptive tasks.