• 천문학회보
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• 제46권2호
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• pp.43.5-44
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• 2021

In the local Universe, the gravitational effects of mass density fluctuations exert perturbations on galaxies' redshifts on top of Hubble's Law, called 'peculiar velocities'. These peculiar velocities provide an excellent way to test the cosmological model in the nearby Universe. In this talk, we present new cosmological constraints using peculiar velocities measured with the 2MASS Tully-Fisher survey (2MTF), 6dFGS peculiar-velocity survey (6dFGSv), the Cosmicflows-3 and Cosmicflows-4TF compilation. Firstly, the dipole and the quadrupole of the peculiar velocity field, commonly named 'bulk flow' and 'shear' respectively, enable us to test whether our cosmological model accurately describes the motion of galaxies in the nearby Universe. We develop and use a new estimators that accurately preserves the error distribution of the measurements to measure these moments. In all cases, our results are consistent with the predictions of the Λ cold dark matter model. Additionally, measurements of the growth rate of structure, fσ8 in the low-redshift Universe allow us to test different gravitational models. We developed a new estimator of the "momentum" (density weighted peculiar velocity) power spectrum and use joint measurements of the galaxy density and momentum power spectra to place new constraints on the growth rate of structure from the combined 2MTF and 6dFGSv data. We recover a constraint of fσ8=0.404+0.082-0.081 at an effective redshift zeff=0.03. This measurement is also fully consistent with the expectations of General Relativity and the Λ Cold Dark Matter cosmological model.

• Clinics in Shoulder and Elbow
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• 제26권3호
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• pp.260-266
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• 2023

Background: Knowledge of the base rate of signal changes consistent with distal biceps tendinopathy on magnetic resonance imaging (MRI) has the potential to influence strategies for diagnosis and treatment of people that present with elbow pain. The aim of this study is to measure the prevalence of distal biceps tendon signal changes on MRIs of the elbow by indication for imaging. Methods: MRI data for 1,306 elbows were retrospectively reviewed for mention of signal change in distal biceps tendon. The reports were sorted by indication. Results: Signal changes consistent with distal biceps tendinopathy were noted in 197 of 1,306 (15%) patients, including 34% of patients with biceps pain, 14% of patients with unspecified pain, and 8% of patients with a specific non-biceps indication. Distal biceps tendon changes noted on radiology reports were associated with older age, male sex, and radiologists with musculoskeletal fellowship training. Conclusions: The finding that distal biceps MRI signal changes consistent with tendinopathy are common even in asymptomatic elbows reduces the probability that symptoms correlate with pathology on imaging. The accumulation of signal changes with age, also independent of symptoms, suggests that tendon pathology persists after symptoms resolve, that some degree of distal biceps tendinopathy is common in a human lifetime, and that tendinopathy may often be accommodated without seeking care. Level of evidence: IV.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.1-10
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• 2018

Spool displacement of a direction control valve is the standard signal to measure the bandwidth frequency of the direction control valve. When the spool displacement signal is not available, it is suggested in this study to use the metering hydraulic line as an alternative way to measure - 90 degree phase bandwidth frequency of the hydraulic direction control valve. Dynamics of the hydraulic line is composed of inertia, capacitance, and friction effects. The effect of oil inertia is dominant in common hydraulic line dynamics and the line dynamics is close to a derivative action in a range of high frequency; such as a range of bandwidth frequency of common directional control valves. Phase difference between spool displacement and line load pressure is nearly constant as a valve close to 90 degree. If phase difference is compensated from the phase between valve input and pressure, compensated phase may be almost same as the phase of spool displacement that is a standard signal to measure phase bandwidth frequency of the directional control valve. A series of experiments were conducted to examine the possibility of using line pressure in to measure phase bandwidth frequency of a directional control valve. Phase bandwidth frequency could be measured with relatively high precision based on metering hydraulic line technique and it reveals consistent results even when valve input, oil temperature, and supply pressure change.

• 한국직업건강간호학회지
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• 제27권3호
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• pp.139-151
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• 2018

Purpose: This review aimed to integrate the results of studies related to job embeddedness of clinical nurses and suggest directions for future research. Methods: A search for relevant studies was conducted using six databases according to the predetermined index terms "nurse" and "job embeddedness." A total of 28 studies that met the inclusion criteria were selected and analyzed. Results: The definition of job embeddedness was consistent in the articles, but the terms, scope, and use of tools to determine job embeddedness were not. In addition, no article suggested a theoretical framework. In all the studies except one, the tool used to measure job embeddedness was one revised from Mitchell et al. (2001). In 15 articles, a negative correlation was found between job turnover and turnover intention. Job embeddedness was also found to be associated with nurses' work environment, organizational citizenship behavior, and organizational commitment, and it had a positive impact on these variables. Conclusion: Job embeddedness can be used as a major variable to explain nurses's turnover intention. Job embeddedness is multidimensional, and a theoretical framework is needed to explain the job embeddedness of clinical nurses. Tools specific to Korea should be developed to measure the job embeddedness of Korean clinical nurses.

• 정보학연구
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• 제1권2호
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• pp.181-193
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• 1998

주가지수선물거래에 있어 외국인의 투자제한이 완전히 철폐된 상태이고, 특히 이들 거래가 우리나라 기관투자자 뿐만 아니라 일반개인에게까지 정보의 주도자로써 미치는 영향이 클 수밖에 없다. 그래서 이들 외국인이 우리나라 선물시장에서 과연 어떠한 거래를 하고 있는 지에 대하여 비거주외국인은행, 비거주외국인증권회사, 비거주외국인계약형투신, 비거주외국인기타법인, 거주외국인증권회사로 구체화시켜 분석하였다. 이 논문은 외국인의 하루중 투자가 어떠한 패턴을 그리고 있으며 특히 이들 외국인간의 정보유입에 따른 시간대별 유의적인 차이를 보이고 있는지에 대하여 실증분석하였다.

• 한국중재학회지:중재연구
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• 제25권1호
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• pp.65-86
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• 2015

Under current international investment law clear criteria to determine standards of indirect expropriation are absent. Arbitral tribunals determine on a case-by-case whether an indirect expropriation has occurred by conducting a fact-based inquiry. However, three common determination standards can be inferred by analyzing prior arbitration cases. The appropriate analytical framework that can be applied to determine whether a state's measure constitutes an indirect expropriation is as follows. i) the degree of economic invasion of the state's action into the foreign investor's property rights and durability of the period, ii) interference with the foreign investor's distinct and reasonable investment-backed expectations, and iii) the nature, purpose and character of the state's measure. Therefore, it is necessary to fully acknowledge and to utilize strategically this determination standard. However, derived standards cannot be applied to all disputes en masse. So, it is desirable to exclude ambiguity and to clearly define the determination standard of indirect expropriation in investment agreements, since arbitral tribunals can apply different determination standards on a case-by-case basis. And, based on the discussions until now, more developed standards and direction in response to demand should be established through consistent analysis and review of precedents related to indirect expropriation. Lastly, This study is expected to be a useful guideline to prepare a necessary countermeasure to prevent dispute related to indirect expropriation beforehand or in case of dispute occurrence.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.234.1-234.1
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• 2014

Many studies have been investigated on high density plasma source (Electron Cyclotron Resonance[ECR], Inductively Coupled Plasma[ICP], Helicon plasma) for large area source after It is announced that productivity of plasma process depends on plasma density. Among them, Some researchers have been studied on multiple sources In this study, we attempted to determine the possibility of multiple inductively coupled plasma (ICP), and helicon plasma sources for large-area processes. Experiments were performed with the one and two coils to measure plasma and electrical parameters, and a circuit simulation was performed to measure the current at each coil in the 2-coil experiment. Based on the result, we could determine the possibility of multiple ICP sources due to a direct change of impedance due to current and saturation of impedance due to the skin-depth effect. However, a helicon plasma source is difficult to adapt to the multiple sources due to the consistent change of real impedance due to mode transition and the low uniformity of the B-field confinement. As a result, it is expected that ICP can be adapted to multiple source for large-area processes.

• Korea-Australia Rheology Journal
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• 제19권2호
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• pp.75-80
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• 2007

The slotted plate technique has previously been shown to be a successful method for directly measuring the static yield stress of suspensions. In this study, we further establish the usefulness of the slotted plate device as a rheometer especially at low shear rates, taking advantage of the extremely low speeds of the slotted plate technique. Newtonian fluids, a shear thinning fluid, and yield stress fluids were tested using the slotted plate device and the results were compared with those from a commercial rheometer using different standard flow geometries. The relationship between the stress on the plate and the viscosity for the slotted plate device obtained by dimensional analysis (drag) predicts a linear relationship between the force at the plate and the plate speed, consistent with the experimental data. The slotted plate device can measure viscosities at very low shear rates. The apparent viscosity - shear-rate data obtained from the slotted plate device are complementary to those obtained using a commercial rheometer. That is : the slotted plate can measure viscosity in the shear rate range $10^{-7}<\dot{\gamma}<10^{-3}\;s^{-1}$, while the commercial rheometer measures viscosity at shear rates higher than $10^{-3}\;s^{-1}$.

• Environmental Analysis Health and Toxicology
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• 제12권3_4호
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• pp.43-54
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• 1997

Species, doses and routes extrapolation can be sucessfully carried out by using a physiologically-based pharmacokinetic (PBPK) approach. And PBPK approach to assess risk of hazardous chemicals is reasonable whatever the exposure scenarios are happened. Both partitioning coefficients of chemical between tissue and blood and enzymatic metabolic rate constants are key parameters to build up the PBPK model. In this study, we tried to estimate in vitro metabolic rate constants using a special apparatus instead to measure the in vivo constants which are used to PBPK simulation since the in vitro tests are less expensive and more convenient than in vivo tests. For the purpose, we designed and tested the new system to measure continuously the headspace concentration of VOC. The newly designed system is composed with a diffusion chamber which generates gaseous substrate, a reaction vessel with a recirculating pump to establish a closed system, an autbmatic sampler from a gas phase, a gas chromatography to analyze the headspace. In addition, a cold water condenser is attached between the reaction vessel and pump to reduce the content of gaseous moisture which interferes with chemical analysis. To validate the newly developed methodology, in vitro metabolic rate constants of trichloroethylene (TCE) as a prototype VOC were estimated by simulating observed results with an ACSL program. The simulated results are consistent to those estimated by the other research groups. This finding suggests that our newly designed closed system may be a useful apparatus to estimate in vitro metabolic rate constants for VOC.

• Toxicological Research
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• 제30권3호
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• pp.185-191
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• 2014

Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health.