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        검색결과 1,048

        81.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to understand the concept of zero-waste design and to apply Sophia Vyzoviti’s folding techniques to develop a zero-waste fashion design method that contributes to sustainable fashion design. In this study, we explore the method and characteristics of zero-waste fashion design based on the concept of folding described in Sophia Vyzoviti’s book on folding techniques. Using the autonomy of Sophia Vyzoviti’s folding technique, four changeable folding fashion designs were developed and produced, demonstrating zero-waste fashion design. The results were as follows. First, the development of fashion designs using Sophia Vyzoviti’s folding techniques enabled the development and production of free and creative zero-waste fashion designs that were three-dimensional, continuous, fluid, and full of potential. Second, the production of zero-waste patterns was further developed into a transformable fashion design that can be used with geometric patterns. These folding techniques produced a fashion design method that could transform one piece of clothing, demonstration the potential for maintenance of creativity using a zero-waste design based on these folding techniques. Third, the double-faced fabric, Neoprene, was chosen as an appropriate material as it emphasizes the depth of folding with application of two colors and its cotton/polyester blend that is suitable for folding.
        4,900원
        82.
        2022.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Polarimetric measurements of the lunar surface from lunar orbit soon will be available via Wide-Field Polarimetric Camera (PolCam) onboard the Korea Pathfinder Lunar Orbiter (KPLO), which is planned to be launched in mid 2022. To provide calibration data for the PolCam, we are conducting speckle polarimetric measurements of the nearside of the Moon from the Earth’s ground. It appears that speckle imaging of the Moon for scientific purposes has not been attempted before, and there is need for a procedure to create a “lucky image” from a number of observed speckle images. As a first step of obtaining calibration data for the PolCam from the ground, we search for the best sharpness measure for lunar surfaces. We then calculate the minimum number of speckle images and the number of images to be shift-and-added for higher resolution (sharpness) and signal-to-noise ratio.
        4,200원
        83.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was aimed to investigate the operational meal costs by kindergarten size in Seoul and to analyze recognition for optimal meal prices. A survey (31.6% recovery rate) was conducted on all kindergartens (779 kindergartens) in Seoul on April 2021 using descriptive analysis, t-test, and dispersion method. A price sensitivity measurement (psm) method was used to determine optimal meal prices. Result showed an average food cost for kindergartens of 2,647 won, an average labor cost of 605 won, an average operating cost of 146 won, and the total meal cost of 3,506 won. Total meal cost decreased with increasing kindergarten size (p<0.001). On the other hand, kindergartens with more students decreased the ratio of food cost to total meal cost, and operating cost and labor costs (p<0.001) increased. The optimal price of kindergarten operators' meal cost (OPP) was KRW 3,673. Furthermore, the analysis showed the sensitivity of operators' meal costs to kindergarten size was insignificant.
        4,000원
        84.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we propose a flow velocity evaluation scheme based on pressure measurement in pressurized pipeline systems. Conservation of mass and momentum equations can be decomposed into mean and perturbation of pressure head and flowrate, which provide the pressure head and flowrate relationship between upstream and donwstream point in pressurized pipeline system. The inverse impedance formulations were derived to address measured pressure at downstream to evaluation of flow velocity or pressure at any point of system. The convolution of response function to pressure head in downstream valve provides the flow velocity response in any point of the simple pipeline system. Simulation comparison between traditional method of characteristics and the proposed method provide good agreements between two distinct approaches.
        4,000원
        85.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 액체감쇠역전회복(FLAIR) 시퀀스를 대체하였던 방법 중에 비교적 간단하면서 높은 재현성을 나타내었던 고신호 강도제거 원리를 MAGiC에 적용하여 MAGiC-FLAIR와 기존의 고속스핀에코-FLAIR 영상과 비교하여 고신호 강 도제거영상의 유용성과 임상적으로 유의미한 기준을 제시하고자 하였다. 연구방법은 MAGiC 적용 후 MAGiC-FLAIR와 MAGiC-고신호 강도제거 영상을 재구성하여, 기존의 고속스핀에코-FLAIR 영상과 각각 정성적, 정량적 평가를 비교하였 다. 정성평가결과 MAGiC-고신호 강도제거는 MAGiC-FLAIR 보다는 월등히 우수하며, 고속스핀에코-FLAIR와 유사한 결과를 보였고, 정량평가결과 MAGiC-고신호강도제거는 MAGiC-FLAIR보다 백질과 회백질 대조도는 더 우수할 뿐만 아 니라, 뇌척수액의 신호 억제도 우수한 결과를 나타냈다. Synthetic 영상을 통하여 획득한 다양한 대조도 영상 중 FLAIR의 부정확도를 고신호 강도제거기법을 적용한다면 진단적 가치를 개선하여 제공할 수 있을 것이다.
        4,000원
        86.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고속스핀에코 기법을 이용한 MRI 검사에서 영상 변수가 전자파 흡수율(SAR)과 온도 증가에 미치는 영향을 평가해 보고자 하였다. 이를 위해 인체 등가 조직 팬텀을 제작하였고 같은 조건에서 재위상화 RF의 FA와 ETL을 증가시키 며 MRI 검사를 시행하였다. SAR는 장비에서 계산된 두부 SAR값을 사용하였고 팬텀의 온도 변화는 양성자 공명 주파수를 이용해 계산하였다. 실험 결과, FA를 60°에서 180°까지 증가시켰을 때 SAR는 약 8배까지 상승하였고 팬텀의 온도 상승의 폭은 약 2.8배(0.21°-0.599°) 증가하였다. 그리고 다중 회귀 분석 결과, FA는 SAR와 온도 상승의 관계에서 표준화 계수 가 각각 0.935, 0.741로 나타나 높은 상관관계를 보였다. ETL은 15에서 30까지 증가시켰을 때 SAR는 약 2배 증가하였 다. 하지만 팬텀의 온도 상승 폭은 오히려 39.2%(0.53°-0.303°) 감소하였다. 다중 회귀 분석 결과에서도 ETL은 SAR의 관계에서 표준화 계수가 0.741로 양의 상관관계를 보였지만 온도 상승의 경우 표준화 계수가 –0.482로 나타나 음의 상관 관계가 있었다. 이는 ETL이 15에서 30까지 증가함에 따라 검사 시간이 약 43% 짧아져 전자파의 노출 시간이 감소한 것이 원인이 될 수 있다. 결국, FSE 기법을 이용한 MRI 검사에서는 재위상화 FA는 최소화하고 기준 SAR 범위 내에서 ETL을 최대로 적용하면 전자파로 인한 온도 상승을 최소화할 수 있어 환자 안전을 증진 시킬 수 있을 것으로 기대한다.
        4,000원
        87.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 딥러닝 알고리즘을 이용하여 딸기 영상 데이터의 병충해 존재 여부를 자동으로 검출할 수 있는 서비스 모델을 제안한다. 또한 병징에 특화된 분할 이미지 데이터 세트를 제 안하여 딥러닝 모델의 병충해 검출 성능을 향상한다. 딥러닝모델은 CNN 기반 YOLO를 선정하여 기존의 R-CNN 기반 모델의 느린 학습속도와 추론속도를 개선하였다. 병충해 검 출 모델을 학습하기 위해 일반적인 데이터 세트와 제안하는 분할 이미지 데이터 세트를 구축하였다. 딥러닝 모델이 일반 적인 학습 데이터 세트를 학습했을 때 병충해 검출률은 81.35%이며 병충해 검출 신뢰도는 73.35%이다. 반면 딥러닝 모델이 분할 이미지 학습 데이터 세트를 학습했을 때 병충해 검출률은 91.93%이며 병충해 검출 신뢰도는 83.41%이다. 따 라서 분할 이미지 데이터를 학습한 딥러닝 모델의 성능이 우 수하다는 것을 증명할 수 있었다.
        4,000원
        89.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Large-area graphene of the order of centimeters was deposited on copper substrates by low-pressure chemical vapor deposition (LPCVD) using hexane as the carbon source. The effect of temperature and the carrier gas flowrates on the quality and uniformity of the as-deposited graphene was investigated using the Raman analysis. The film deposited at 870 °C with a total carrier gas flowrate of 50 sccm is predominantly single-layer with very low defects according to the Raman spectra. The 2D/G peak intensity ratios obtained from the Raman spectra of samples from three different locations of graphene deposited on a whole copper catalyst was used to calculate the large-area uniformity. Based on the results, a very high uniformity of 89.6% was calculated for the graphene deposited at 870 °C. The uniformity was observed to decrease with increasing temperature. Similar to the thickness uniformity, the electrical conductivity values obtained as a result of I–V measurements and water contact angle measurements were found to be close to each other for the graphene deposited under the same deposition conditions.
        4,000원
        90.
        2022.05 구독 인증기관·개인회원 무료
        For spent nuclear fuel transferred to dry storage facilities, it is difficult to apply safeguards approaches and long-term integrity verification due to the structural characteristics of the facility. There is a need to check the integrity of the nuclear fuel assembly before transferring it to a dry storage facility and are need to provide information on whether there are any defects. At the Korea Institute of Nuclear Nonproliferation and Control, as a non-destructive testing technology for ensuring Continuity of Knowledge (CoK) of the dry storage facilities, a methodology for reconstructing images by neutron tomographic technique from spent nuclear fuel using a He-4 gas scintillation detector was presented. It is thought that the He-4 gas scintillation detector-based technology can be used to verify the defect of the nuclear fuel assembly. This methodology must be accompanied by accurate neutron measurements. The place where the technique was conducted is surrounded by a concrete wall. Concrete contains water molecules, which can affect neutron measurements. In this study, reconstruction images based on neutron measurements and MCNP simulations are compared to verify the effects of the concrete. Neutron measurements were performed by measuring Cf-252 neutron sources in a 1/10 lab-scale TN- 32 cask with six He-4 gas scintillation detectors as an array. Neutron sources are fixed at each point in the cask, and the He-4 detector array is rotated from 0° to 360° at 10° intervals to reconstruct the image using the filtered back-projection (FBP) method. Also, in MCNP reconstructed images, there are two versions depending on whether concrete wall. The source image and ring shape were found in the measurement-based thermal neutron reconstruction image, which was similar to the simulation image that considering the concrete effects. On the other hand, in the simulation reconstruction image without the concrete, only the shape of the source was found. Thus, the effect of concrete should be considered when performing the neutron tomographic techniques using He-4 gas scintillation detectors.
        91.
        2022.05 구독 인증기관·개인회원 무료
        In this study, a drop analysis of metallic disposal containers for radioactive wastes is performed according to accident scenarios at the disposal site. The weight of the disposal container is about 8 tons, and the ingot-type wastes are loaded in the disposal container. To simulate the floor of the disposal site as the impact target, the reinforced concrete pad is modeled. High impact energy of the disposal container due to their heavy weight and high drop height causes excessive deformation and failure of the concrete target having relatively weak strength. Dynamic growth of cracks due to such failures causes penetration and delamination of concrete. Since the impact force delivered to the container strongly depends on the failure of the concrete pad, it is important to properly simulate the failure of the concrete in the drop analysis. A material erosion method can be used to simulate the concrete failure. In the case of applying erosion based on the finite element method (FEM), the element is deleted when the element exceeds a certain criterion, which causes material and energy loss problem. To solve this problem, mesh-free methods such as smoothed particle hydrodynamics (SPH) can be commonly used, but the mesh-free method has the disadvantage of incurring high numerical cost. Therefore, an adaptive method combining SPH and FEM-based SOLID elements is used for concrete target modeling to simulate excessive deformation and failure of the concrete target. In the adaptive coupling method of SPH and SOLID, the concrete target is first modeled as a solid element. When the damage of concrete exceeds the failure criterion, the solid element is eroded and the SPH element replacing the solid element is activated. Since the activated SPH element continues to participate in the impact, the problem of loss of materials and energy can be effectively solved. In this way, analysis results consistent with actual physical phenomena can be obtained.
        92.
        2022.05 구독 인증기관·개인회원 무료
        Waste that contains or is contaminated with radionuclides arises from a number of activities involving the use of radioactive material. Such activities include the operation and decommissioning of nuclear facilities; the use of radionuclides in medicine, industry, agriculture, research and education. Radioactive waste must be safely disposed in a radioactive waste repository for the protection of public health and the environment. In order to safely dispose of radioactive waste in a repository, it is important to derive an optimal predisposal management scenario because radioactive waste must be processed (i.e. processing (pretreatment, treatment and conditioning), storage and transport) for satisfying waste acceptance criteria (WAC). Optimal scenario of predisposal management of radioactive waste is derived for considering the balancing of exposures of workers and/or those of members of the public, the short term and long term risk implications of different waste management strategies, the technological options available and the costs. However, existing studies for deriving the optimal scenario of predisposal management of radioactive waste have evaluated only the radiation dose of workers and public within given scenarios using fixed value, or have derived optimal single process (i.e. decontamination) of predisposal management using Multi-Attribute Decision Making (MADM) methodology. In this study, optimal predisposal management scenario is derived by evaluating exposures of workers using system dynamics (SD) technique. Radiation dose assessment SD model was modeled using VENSIM® code developed by VENTANA systems Inc.. SD Model has the advantage of being able to respond flexibly when decision makers want to change input data and it has the advantage of being able to track dynamically changing phenomena and visually confirm interdependence. After that, based on the SD model derived from this study, evaluations of exposures of public, cost, and technicality will be added to be utilized when establishing an optimal scenario of predisposal management of radioactive waste considering multi attribute.
        93.
        2022.05 구독 인증기관·개인회원 무료
        Various models have been proposed to describe the swelling behavior of buffer in high level waster repository. One of the most notable models, the Barcelona Basic Model (BBM), is a mechanical model that simulates the behavior of unsaturated ground and is widely applied to soils that undergo large expansion due to water. Among the BBM parameters of Kyeongju bentonite, which is found in Korea, there are no experimental data for parameters that describe the unsaturated state. Such hydromechanical properties should be characterized through experimental programs. However, such experiments are highly complicated and require long periods of time to produce an unsaturated state through different methods according to the suction range. Although there are several studies in which geotechnical parameters were obtained through a back analysis instead of direct experiments, few studies have employed machine learning methods for the identification of geotechnical parameters. In this study, instead of direct experiments, the results of a relatively simple swelling pressure experiment was compared to the numerical analysis results to propose a method of determining some of BBM parameters. Influential factors were identified by a sensitivity analysis and the values of the factors were estimated using an artificial neural network and optimization method. The obtained parameters were applied to the numerical model to estimate the swelling pressure growth, which was subsequently compared to the experimental value. As a result, it was found that there was no significant difference between the two swelling values.
        94.
        2022.05 구독 인증기관·개인회원 무료
        Molten salt immersion technique has been tested with several Sr oxides, SrZrO3, SrMoO4 and U2SrOy, and MgCl2 based molten salts for the Sr nuclide separation. Reaction time, temperature, and salt composition were varied to effectively separate Sr in chloride forms. ICP-OES, XRD, and SEM analysis were conducted for the conversion efficiency and structure and morphology analysis. It is confirmed that all experiments of SrZrO3 with MgCl2 at 800°C for reaction time 5, 10, 20 hours showed higher conversion efficiency than 99% and in LiCl-KCl-MgCl2 and NaCl-MgCl2 molten salts at 500°C or 600°C, conversion efficiency higher than 97% was obtained. SrMoO4 in MgCl2 immersion experiments for 10 hours showed higher conversion efficiency than 99% when the molar ratio of salt/oxide powder is 7. U2SrOy was also tested with MgCl2 molten salt at 800°C and higher efficiency than 99% and mainly MgUO4 were produced as a reaction product.
        96.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The waterpower generation of the dam generates electricity by revolving the turbine through a water pipe using the difference of high/low of water, the revolving turbine makes an occurrence a terribly loud noise. Accordingly, in the water turbine generator room located on such hydroelectric generator, since a mutual communication is not establish properly when working, they are suffering many difficulties, and it is real state that such noise damages even to those workers in the office of power plant. Since the most of dam water turbine generator room built in domestic country had used the finishing materials of a huge volume and a high reflexibility, it is carrying more amplifying function with the turbine noise arising when generates the electricity. Therefore, there is not only a difficulty for mutual communication among those workers in the workplace, but also it becomes an obstruction factor for working even to the workers in the adjacent office, and because they are suffering the mental and physical damages, it is actual state that a noise-reduction measure is urgently needed. As a result of the study, on the object with the dam hydraulic turbine dynamo room in which an acoustic defect is being occurring, this Study has conducted the Psycho-Acoustics Experiment about the Delivery of Voice Information using Auralization Technique that can experience the Virtual Acoustic Field. It is considering that such study result could be used usefully for improvement of the Voice Definition when construction the dam hydraulic turbine dynamo room, in the future.
        4,000원
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