• 천문학회지
• /
• 제56권2호
• /
• pp.137-147
• /
• 2023

Shoushili was the official calendrical method promulgated in 1280 CE by the Yuan dynasty. It contains a list of the angular spans in right ascensions for the 28 lunar lodges. They are known to have been measured by Guo Shoujing with his advanced instruments with an unprecedented precision or reading error of 5'. Such precise data are useful to determine their observational epoch with an error range which is narrow enough to pinpoint on which historical occasion they were observed. Using the precise SIMBAD data based on eDR3 of GAIA and carefully identified determinative stars and considering the precession of equinoxes and proper motions, we apply linear regression methods to those data and obtain the observational epoch of 1271 ± 16 CE and the measurement error of 4.1'. We also have polar distances corresponding to declinations written in another manuscript of the Ming dynasty. Since the two data sets have similar significant digits, they were suggested to have the same origin. However, we obtain their observational epoch of 1364±5 CE and the measurement error of 5.7'. They must have been measured with different instruments and on a different occasion from the observations related to Shoushili. We review the history of the calendrical reform during the 13th century in the Yuan dynasty. We conclude that the observational epoch obtained from lodge spans in Shoushili agrees with the period of observations led by Guo Shoujing or 1276-1279 CE, which is also supported by the fact that the ecliptic lodge span values listed in Shoushili were calculated from the equatorial lodge spans.

• 생물정신의학
• /
• 제19권4호
• /
• pp.159-163
• /
• 2012

An appropriate research design for hypotheses and purposes leads to a good quality of research results. In this review article, we summarized the types of research methods and described the characteristics of clinical trials. Research designs are categorized into observational studies and experimental ones, depending on data collecting methods. In an observational study, there are cross-sectional, cohort and case-control studies. Parallel groups design and crossover trial studies are representative designs in a randomized controlled trial study, a kind of experimental study. Clinical researchers should understand the characteristics of clinical research designs including advantages and disadvantages and choose the suitable design according to their study purposes and the nature of collected data or subjects.

• 산업경영시스템학회지
• /
• 제35권3호
• /
• pp.187-191
• /
• 2012

The methods for constructing network of observational locations for measuring water quality in water reservoirs have been widely proposed, but they had some limitations to be applied to river areas, which lie in awkward clustering and finding representative observational locations among locations within each clustering. In this paper, a statistical approach to detect anomaly locations which were significantly different in important measurements for the water quality from the previous locations and construct observational network with them was proposed. Anomaly was detected with the sampling distribution of each primary principal component score, sum of primary PCs, or sum of residual PCs. The empirical study with the data of Nakdong Dam for guiding how to use our proposed approach and showing limitations of previous studied was described.

• Communications for Statistical Applications and Methods
• /
• 제30권1호
• /
• pp.1-19
• /
• 2023

Observational data with missing or incomplete data are common in biomedical research. Multiple imputation is an effective approach to handle missing data with the ability to decrease bias while increasing statistical power and efficiency. In recent years propensity score (PS) matching has been increasingly used in observational studies to estimate treatment effect as it can reduce confounding due to measured baseline covariates. In this paper, we describe in detail approaches to competing risk analysis in the setting of incomplete observational data when using PS matching. First, we used multiple imputation to impute several missing variables simultaneously, then conducted propensity-score matching to match statin-exposed patients with those unexposed. Afterwards, we assessed the effect of statin exposure on the risk of heart failure-related hospitalizations or emergency visits by estimating both relative and absolute effects. Collectively, we provided a general methodological framework to assess treatment effect in incomplete observational data. In addition, we presented a practical approach to produce overall cumulative incidence function (CIF) based on estimates from multiple imputed and PS-matched samples.

• 성인간호학회지
• /
• 제23권2호
• /
• pp.111-122
• /
• 2011

Purpose: The aim on this study was to establish the validity, reliability and efficiency of a Pain Self-Report Scale for elderly with dementia and compare these results with an observational pain rating scale. Methods: Study subjects were 136 elderly with dementia who were residents in a nursing home, geriatric hospital, or day care center. The subject's pain was measured by five self-report scales and observational scale. DS-DAT (discomfort scale-dementia of the Alzheimer's type) was used for pain behavior observational measure. Cognitive state was assessed using the MMSE (Mini-Mental State Examination). Results: Observational rating correlated moderately with self-report (r=.225~.585, p<.05) and tended to underestimate pain intensity. Test-retest reliability was high for all five self-report scales, and the correlation between these scales was very strong (r=.735~.856, p<.05). Comprehension rate of VDS (verbal descriptor scale) was 88.3%, and NRS (numeric rating scale) 69.9%, FPS (face pain scale) 66.9%, HVAS (horizontal visual analog scale) and VVAS (vertical visual analog scale) 65.4%. Conclusion: Nurses should not apply observational scales routinely in demented patients as many of these are capable of reporting their own pain. Self-report, the highest standard of pain measurement can be reliably performed in a large proportion of demented elderly.

• 대기
• /
• 제25권1호
• /
• pp.99-115
• /
• 2015

To investigate the influences of the observational nudging and the analysis nudging on the WRF simulation for the heavy snowfall event in Yeongdong area on 26 February 2012, the sensitivity experiments in relation to nudging effects were conducted. We initially set the magnitude of nudging coefficient of $6.0{\times}10^{-4}s^{-1}$ to apply to the analysis nudging experiments and observational experiments. To select the optimized options for the observational nudging, the radius influence experiment was carried out with radii ranging from 10 to 25 km at 5 km intervals. Among the observational nudging experiments, the experiment, which was conducted with the option of the radius influence of 15 km and that of the nudging coefficient of $6.0{\times}10^{-4}s^{-1}$ (ONG exp.), showed a best result. As giving the nudging effect only directly on D1 and D2 brought about a better result for the analysis nudging, we set the analysis nudging experiment as above (ANG exp.). We compared and analyzed the results from the control experiment, ONG experiment, and ANG experiment to reveal nudging effects. It was found that the control experiment brought about a result that it overestimated its precipitation in comparison with the observation and failed to properly simulate the time zone of rainfall concentration. When either of the two nudging (observational and analysis nudging) was applied to the data assimilation, it brought about a better result than the control experiment. Especially the observational nudging led to a meaningful result for the wind field, while the analysis nudging had the best result for the precipitation distribution among the experiments.

• The Journal of Korean Physical Therapy
• /
• 제33권2호
• /
• pp.53-61
• /
• 2021

Purpose: This study examined the impacts of action observational physical training related to stair walking on the stair walking ability and self-efficacy of chronic stroke patients. Methods: This study was conducted on 24 chronic stroke patients, who were assigned randomly to an action observational physical training group (12 persons) and a landscape observation physical training group (12 persons). To the action-observational physical training group, five videos related to stair walking were presented, and after observing them, physical training was carried out. The landscape observation physical training group observed the videos consisting of landscape, where there were no humans and animals, and then underwent physical training. This study measured the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius to examine the muscle activity of the lower limb. A timed up and go and step test was performed to examine the balance ability, and a timed stair test was conducted to examine their stair walking ability. A self-efficacy scale was measured to examine the degree of their confidence of performing stair walking. The assessment was conducted three times in total: pre-, post-, and follow-up surveys. Results: As a result of this study, the action observational physical training group significant improvement after the intervention than in the landscape observation physical training group. Moreover, the follow-up study four weeks after the intervention showed significant improvements in the action observational physical training group (p<0.05). Conclusion: These results show that the action observational physical training had a positive impact on the stair walking ability and self-efficacy of chronic stroke patients.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1998년도 학술발표회 발표논문집
• /
• pp.401-406
• /
• 1998

This study aimed at the technique for the construction control in braced excavation works. Selecting a case of Kwangju subway works, field observational values were compared with prediction using Plaxis's. Maximum observational values relevant to both horizontal and vertical proved satisfactory in that they were within the criteria. Numerical results by used Plaxis were overestimated greater than observational values, which meant the prediction were safe tendency. .It must be emphasized that displacement measurement for neighboring important structures should be carried out in order to take countermeasure charge for construction methods, in case that the risk or failure was previewed.

• 한국지반공학회지:지반
• /
• 제14권2호
• /
• pp.41-54
• /
• 1998

지반의 불균질성, 토질상수의 측정에 연관된 오차. 압밀이론의 단점 등으로 예측된 압밀침하량 및 시간은 항상 실측치와 잘 일치하지 않게 된다. 압축성 지반 위에 성토가 이루어질 때, 최종 침하량과 압밀시간을 예측하기 위한 예측기법은 실무에서 유용한 수단이다. 그러나, 기존의 예측기법들에 의한 침하곡선에서 직선을 찾기가 어렵거나, 개인오차를 피할 수 없는 등의 단점을 내포하고 있다. 본 논문에서는 새로운 예측기법($\sqrt{s}$법)으로 현장에서 압밀해석을 수행하기 위하여 제안되었다. 두 현장에 대하여 $\sqrt{s}$-법과 함께 다른 기존의 방법들을 적용한 결과, $\sqrt{s}$법과 Asaoka법에 의해 예측된 최종침하량은 실측치와 좋은 일치를 보여주었으나, 쌍곡선법(Tan, 1991)에서는 항상 과대평가된 결과를 또한 Hoshino 법에서는 많은 경우에 예측이 불가한 결과를 보여주었다.$\sqrt{s}$- 법에 의한 침하곡 선상에서 평균압밀도가 60%와 90% 사이에서 직선을 나타내고 있어서 개인오차를 유발할 가능성이 희박하였다. $\sqrt{s}$- 법에 의하여 예측된 최종압밀시간은 실측치와 잘 일치하고 있는 반면에 Asaoka 와 Tan(1996) 방법에 의한 결과는 아주 과소평가되거나 과대평가되었다. 이러한 이유는 후자의 두 방법에서 단계성토의 영향이 고려되지 못했기 때문인 것으로 사료된다.

• The Journal of Korean Physical Therapy
• /
• 제32권1호
• /
• pp.1-6
• /
• 2020

Purpose: This study examined the effects of action observational training to improve the gait function for patients with stroke. Methods: The participants were divided into two groups: right hemiplegia group (n=12) and left hemiplegia group (n=12). All groups received conventional therapy for five sessions for 30 minutes, each for three weeks. Left and right hemiplegia group practiced additional action observational training for five sessions for 20 minutes each for three weeks. They participated in three weeks of action observational training coupled with immediate physical practice (intervention), followed by a final assessment. The duration of each action observation video sequence was 10 minutes, followed immediately by practice of the observed motor skill (10 minutes). The gait velocity, cadence, swing time, step length, and BOS (base of support) were examined using the GAITRite system. Results: The results of this study showed significant improvement in the gait function. The outcomes of the gait abilities from gait velocity, cadence, swing time, step length of the affected side, and BOS (base of support) were improved significantly in the right hemiplegia group (p<0.05). In the left hemiplegia group, there was no significant improvement in the gait velocity, cadence, and BOS except for the swing time and step length of the affected side. The left and right group comparisons between the groups were not significant (p<0.05). Conclusion: Action observation training improves the gait function. These results suggest that action observational training is feasible and suitable for stroke patients.