• Physical Therapy Rehabilitation Science
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• 제11권2호
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• pp.215-223
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• 2022

Objective: This study was to resolve the limitations of the experimental environment and to solve the shortcomings of the method of measuring human gait characteristics using optical measuring instruments. Design: A cross-sectional study. Methods: Fifteen healthy adults without a history of orthopedic surgery on the lower extremities for the past 6 months were participated. They were analyzed gait variables using the smart guide and the 3D image analysis at the same time, and their results were compared. Visual-3D was used to calculate the analysis variables. Results: The reliability and validity of the data according to the two measuring instruments were found to be very high; gait speed(0.85), cycle time(0.99), stride time of both feet(0.98, 0.97) stride legnth of both feet(0.86, 0.88) stride per minute of both feet(0.99, 0.96), foot speed of both feet(0.90, 0.91), step time of both feet(0.77, 0.71), step per minute(0.72, 0.74), stance time of both feet(0.96, 0.97), swing time of both feet(0.93, 0.79), double step time(0.81), initial double step time(0.84) and terminal step time(0.76). Conclusions: In the case of the smart insole, which measures human gait variables using the pressure sensor and inertial sensor inserted in the insole, the reliability and validity of the measured data were found to be very high. It can be used as a device to replace 3D image analysis when measuring pathological gait.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.170-177
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• 2023

In quantum mechanics, uncertainty refers to the uncertainty of a measurement physical quantity, because some mechanical quantity can only be in its eigenstate under certain conditions, and the values shown are discrete.The exact value can only be obtained by measuring it in the eigenstate of this mechanical quantity.Uncertainty is like a double-edged sword, which has both advantages and disadvantages in art itself and in the process of artistic creation. In this study, it is divided into three main parts. First, the existence of uncertainties in contemporary art is sorted out in two broad parts, the definition of the uncertainties in art and the specific expression in contemporary art, respectively, with examples from four aspects of psychological impact, accidental presentation effect, expression form and connection with the viewer. The purpose is to understand how uncertainties are expressed in the process of artistic creation. Second, the role of the uncertainties in artistic creation is analyzed through examples, and then it is proposed that artists should use uncertainties to serve art with a scientific and rational attitude. Thirdly, the application of uncertainties in my creative practice and their influences on my painting creation. In summary, every artistic creator should take art seriously and sincerely. The relationship among the creative subject, society and life is an eternal and continuous interaction, and art is a carrier of reflection. For the problems brought by uncertainties in artistic creation, from choosing new certainty by thinking to the emergence of uncertainties, such a cycle is the process of art sublimating from life and being closely related to life.

• 한국인구학
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• 제25권2호
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• pp.163-192
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• 2002

주거밀도는 개인 및 가구의 주거수준을 보여주는 중요한 질적 주거복지 지표다. 이러한 측면에서 주거밀도는 이민자들이 현지 사회로 동화 되어가는 정도를 간접적으로 보여준다. 본 연구에서는 1980년과 1990년의 PUMS(Public Use Microdata Sample)를 사용하여 미국 내의 주요 아시아 세 인종집단(한국인, 중국인, 일본인)의 과밀여부와 추이를 분석하고 있다. 본 연구에서는 1980년과 1990년 주거밀도의 나이효과와 이민효과를 분리하기 위하여 이중생잔모형(Double Cohort Method)을 사용하여 이민자들의 생애주기와 경제적 수준 변화에 따른 10년 동안의 주거밀도 변화추이를 밝혔다. 분석결과는 이민기간이 이민자들의 주거복지 수준에 가장 큰 영향을 끼치는 것으로 나타났다. 이민기간이 10-20년인 1970년대 이민자는 1970년 이전 이민자보다 과밀가구에 살 확률이 높았고 1970년 이전 이민자는 미국출생자보다 높아 현지사회의 거주기간이 중요한 요인임을 알 수 있다 한국인은 이민초기에는 과밀가구에 살 확률이 크지만 거주기간이 증가하면서 그 확률이 급격히 감소하였다. 소득수준이 높을수록, 남자에 비해 여자가 과밀가구에 살 확률이 낮게 나타났다. 과밀가구에 살 확률이 높은 경우는 자가가구에 비해 차가가구, 미국출생자에 비해 1970년대 이민자, 그리고 15-24세 집단에 비해 35-44세 집단과 45-54세 집단이었다. 주거밀도라는 측면에서 분석한 미국내 한국인의 주거복지 변천 과정은 중국인과는 비슷한 수준의 변화론 경험하고 있지만 일본인보다는 낮은 수준의 상향 이동을 경험하고 있었다. 이것은 이민 당시의 국력수준의 차이에 따른 개인의 재산축적 정도, 현지 사회에서 사용 가능한 인적자원의 차이, 그리고 미국사회 동화에 대한 문화적 차이 등이 복합적으로 작용하고 있는 것으로 판단된다.

• Journal of Welding and Joining
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• 제13권1호
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• pp.89-102
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• 1995

The evaluation of reheat cracking susceptibility in CrMoV turbine rotor steel was performed using thermally simulated heat affected zones. The examinations were carried out in terms of microstructural characterization, microhardness measurement and a Charpy type notch opening three point bend test. It was found that reheat cracking susceptibility increased as the peak temperature increased. This effect was due to the combined effects of the carbide dissolution and unrestricted grain growth at 1350.deg. C peak temperature. Reheat cracking susceptibility was estimated based on microhardness measurement and prior austenite grain size. It was established that for this particular material, reheat cracking in coarse grained heat affected zone can be eliminated if the microhardness is below about 360DPH and the grain size is below about 30.mu.m. It is evident that reheat cracking susceptibility can be eliminated or reduced by carefully controlling the welding parameters such that a refined structure is produced in the coarse grained heat affected zone.

• 한국가스학회:학술대회논문집
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• 한국가스학회 1998년도 추계학술발표회 논문집
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• pp.249-254
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• 1998

This paper describes the study of developing air-cooled absorption system which uses a new working solution instead of LiBr solution to improve the performance of system. The absorption chiller-heater considered was an air-cooled, double-effect, $H_2O/LiBr+HO(CH_2)_3$ system of parallel flow type. In this study, we found out the characteristic of new working solution through the cycle simulation and compared the result that of LiBr solution to evaluate. The new working fluid has a wider working range with $8\%$ higher crystallization limit at the saturated refrigerant pressure of 0.8kPa. The optimum designs and operating conditions of air-cooled absorption system were suggested based on this cycle simulation analysis. It was demonstrated that new working fluid substantially improves the performance of the absorption refrigeration machine and is expected to increase the COP by as much as $5\%$.

• 조명전기설비학회논문지
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• 제26권7호
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• pp.16-22
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• 2012

With the increase of consumption of new renewable energy, the use of Electric Double Layer Capacitor(EDLC) is being gradually widened as the next generation energy storage device. In order to expand the market of EDLC which is recently receiving a lot of attraction as a new promising area, development of a charge/discharge cycle tester to measure and test performance, is essential. Therefore, this research designed a circuit to measure capacity and internal resistance and a circuit to measure voltage maintenance properties, based on EDLC's basic charging/discharging properties so it is able to measure the state of charge and discharge at high speed. When evaluating performance characteristics, the 5[V]/100[A] prototype-EDLC charge/discharge testing system developed for this research showed ${\pm}0.1$[%] of accuracy of voltage and current measurement. It was also proved that the developed charge/discharge testing system for EDLC can be applied to the actual industry, when testing the entire system using a program produced for data monitoring and acquisition.

• Geomechanics and Engineering
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• 제14권1호
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• pp.1-8
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• 2018

This paper presents an investigation of the liquefaction characteristics and particle crushing of isotropically consolidated silica sand specimens at a wide range of confining pressures varying from 0.1 MPa to 5 MPa during undrained cyclic shearing. Different failure patterns of silica sand specimens subjected to undrained cyclic loading were seen at low and high pressures. The sudden change points with regard to the increasing double amplitude of axial strain with cycle number were identified, regardless of confining pressure. A higher cyclic stress ratio caused the specimen to liquefy at a relatively smaller cycle number, conversely producing a larger relative breakage $B_r$. The rise in confining pressure also resulted in the increasing relative breakage. At a specific cyclic stress ratio, the relative breakage and plastic work increased with the rise in the cyclic loading. Less particle crushing and plastic work consumption was observed for tests terminated after one cyclic loading. Majority of the particle crushing was produced and majority of the plastic work was consumed after the specimen passed through the phase transformation point and until reaching the failure state. The large amount of particle crushing resulted from the high-level strain induced by particle transformation and rotation.

• Ocean and Polar Research
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• 제27권2호
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• pp.231-235
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• 2005

The European Iron Fertilization Experiment EIFEX studied the growth and decline of a phytoplankton bloom stimulated by fertilising $10km^2$ in the core of a mesoscale $(80{\times}120km)$ cyclonic eddy south of the Antarctic Polar Front with about 2 times 7 tonnes of iron sulphate. The phytoplankton accumulation induced by iron fertilization did not exceed $3{\mu}g\;chl\;a\;l^{-1}$ despite a draw down of $5{\mu}M$ of nitrate that should have resulted in at least double to triple the amount of phytoplankton biomass assuming regular Redfield-ratios for draw down after phytoplankton growth in the Southern Ocean. During EIFEX the fertilized core of the mesoscale eddy evolved to a hotspot for a variety of small and medium sized mesozooplankton copepods. In contrast to copepods, the biomass of salps (Salpa thompson)) that dominated zooplankton biomass before the onset of our experiment decreased to nearly extinction. Most of the species of the rnosozooplankton community showed extremely hiか feeding rates compared to literature values from Southern Ocean summer communities. At the end of the experiment, massive phytoplankton sedimentation reached the sea floor at about 3800m water depth.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.585-592
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• 2022

Treatment of triple-negative breast cancer (TNBC) has been limited due to the lack of molecular targets. In this study, we evaluated the cytotoxicity of hydroxyzine, a histamine H1 receptor antagonist in human triple-negative breast cancer BT-20 and HCC-70 cells. Hydroxyzine inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay showed that hydroxyzine induced apoptosis. The hydroxyzine-induced apoptosis was accompanied down-regulation of cyclins and CDKs, as well as the generation of reactive oxygen species (ROS) without cell cycle arrest. The effect of hydroxyzine on the induction of ROS and apoptosis on TNBC cells was prevented by pre-treatment with ROS scavengers, N-acetyl cysteine or Mito-TEMPO, a mitochondria-targeted antioxidant, indicating that an increase in the generation of ROS mediated the apoptosis induced by hydroxyzine. Western blot analysis showed that hydroxyzine-induced apoptosis was through down-regulation of the phosphorylation of JAK2 and STAT3 by hydroxyzine treatment. In addition, hydroxyzine induced the phosphorylation of JNK and p38 MAPK. Our results indicate that hydroxyzine induced apoptosis via mitochondrial superoxide generation and the suppression of JAK2/STAT3 signaling.

• 에너지공학
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• 제24권3호
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• pp.40-47
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• 2015

석탄가스화 복합발전소는 기존 석탄화력 발전소에 비해 온실가스 및 대기오염물질을 적게 배출할 뿐만 아니라 국제적으로 쉽게 확보할 수 있는 저렴한 저품위 석탄을 사용할 수 있어서 연료를 안정적으로 공급받을 수 있다. 이에 본 논문에서는 석탄가스화 복합발전 건설의 에너지안보 확보편익을 추정하고자 한다. 이를 위해 무작위로 추출된 전국 600가구를 대상으로 설문조사를 수행한 후 얻은 자료에 조건부 가치측정법을 적용하여 분석한 결과를 제시한다. 통계적 효율성의 확보를 위해 이중경계 모형을 적용하며 영(0)의 응답자료를 적절하게 다루기 위해 스파이크 모형을 적용한다. 분석결과 석탄가스화 복합발전소로부터 생산되는 전력 1kWh에 대해 응답자들은 평균적으로 6.05원의 추가적인 지불의사액을 가졌다. 즉 석탄가스화 복합발전소로부터 생산되는 전력에 대한 에너지안보 확보편익은 6.05원/kWh이다. 올해 완공되는 태안 석탄가스화 복합발전소의 예상 연간 발전량은 2.27TWh이므로 에너지안보 확보편익은 연간 13,740백만원으로 추정된다.