• 터널과지하공간
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• 제24권2호
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• pp.166-175
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• 2014

본 연구에서는 현장실측을 통하여 강원도 태백에 위치한 대규모 석탄광산의 열환경을 평가하였다. 열환경 평가를 위하여 WBGT, HSI, ESI, KATA지수 및 유효온도 등 다양한 열적지표를 적용하였고, 상관분석을 실시하였다. 분석결과 대부분의 작업장에서 높은 열환경이 평가되었고, 특히 열적지표 중 인체의 생리학적 특성을 반영하는 HSI와 최대 땀증발열의 상관계수는 -0.834이고 이것은 HSI지표에 가장 큰 영향을 미치는 것으로 나타났다. 최대 땀증발열에 가장 큰 영향을 미치는 인자는 공기속도이다. 따라서 운영 중인 제 1수직갱의 연장 굴착 또는 공기 누기를 방지하기 위한 구조물을 설치함으로써 환기량 증대를 통해 작업장의 열환경을 개선시킬 수 있을 것으로 판단된다.

• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.306-312
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• 2008

This study investigated the influence of pH on the color development of melanoidins formed from amino acid enantiomer model systems. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry. The browning and browning index showed no difference according to the type of amino acid enantiomers, while that formed from the D-Asn system was the only difference according to pH level. The tristimulus value of melanoidins formed from all model systems was located on a dominant wavelength of 475 nm, the blue zone of the diagram. In addition, the $L^*$, $a^*$, $b^*$, $C^*_{ab}$ values, and ${\Delta}E^*$ index on the basis of the type of amino acid enantiomers, the differences were markedly found at pH 4.0. At pH 7.0, significantly differences were found in the $L^*$, $a^*$, $b^*$ values, and ${\Delta}E^*$ index and not in the case of the lysine enantiomers. In addition, at pH 10.0, the differences were found in the $a^*$ and $b^*$ values from the lysine enantiomers and $C^*_{ab}$ value from the asparagine enantiomers. Therefore, the color development of melanoidins was influenced by the type of amino acid enantiomers and pH levels. Especially, it is thought that the $a^*$ and $b^*$ values can be used to explain the differences among the amino acid enantiomers in the color development of melanoidins.

• 대한지리학회지
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• 제44권3호
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• pp.207-223
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• 2009

토양수분의 공간적인 분포를 예측하는 TOPMODEL 지형지수는 지형특성을 기반으로 하는 분포형 환경연구에서 빈번히 활용되는 지형 인자이다. 지형지수에 대한 평가 및 개선은 최근까지도 활발하지만, 대부분은 수정된 다중 유향 알고리듬을 이용한 것들이고, 경사 알고리듬을 이용한 경우는 상대적으로 미흡하다. 본 연구에서는 무한 유향(Dinf) 알고리듬과 Horn 경사 알고리듬을 이용하여 지형지수를 개선하고, 이를 TOPMODEL에 적용하여 모의 수문반응에 대한 영향을 분석하고 평가했다. 연구결과 무한 유향(Dinf) 알고리듬과 Horn 경사 알고리듬을 이용할 경우, 기존 다중 유향(MD8) - 다중 경사(MDS) 알고리듬에 비해 토양수분의 공간적 분포에 보다 근접한 지형지수를 만들 수 있었다. 그러나 최종 유출구의 유출량 모의 효율은 향상되지 않았다. 이 결과는 분포형 환경연구 분야에서 적절한 유향 및 경사 알고리듬을 선택하는데 도움이 될 것이다.

• Journal of Periodontal and Implant Science
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• 제51권3호
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• pp.163-178
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• 2021

Purpose: The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients. Methods: In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs). Results: Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis. Conclusions: Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.

• 한국산림과학회지
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• 제85권3호
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• pp.539-551
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• 1996

본 연구에서는 위치종속조사가법에 의해 소나무임분에서 조사된 자료로부터 임목의 크기 및 경쟁목과의 거리를 함께 고려한 개체목차원의 거리종속경쟁지수와 전통적인 임분차원의 밀도척도를 추정하고 이들을 흉고직경생장과 비교하여 경쟁상태에 대한 설명력을 검토하였으며, 경쟁지수가 영향변수로 고려된 개체목 흉고직경생장식을 유도하였다. 경쟁목선정방법에 있어 경쟁치단각도를 30도로 설정했을 때의 경쟁지수가 흉고직경생장과 기장 높은 상관관계를 보인 반면, 경쟁구역거리는 흉고직경생장추정에 대한 경쟁지수의 설명력에 미미한 영향을 미치는 것으로 나타났다. 개체목별 거리종속경쟁지수에 근거한 대부분의 임분경쟁지수들은 임분의 경쟁상태를 비슷하게 나타내는 것으로 평가되었다. 임령과 지위지수의 영향을 배제한 상태에서의 편상관분석결과 Alemdag의 평균경쟁지수 및 상대공간지수가 흉고직경과 가장 높은 연관성을 나타냈는데, 이중 개체목의 위치를 파악하지 않고도 비교적 손쉽게 파악될 수 있는 상대공간지수가 임분의 평균흉고직경을 추정하는데는 좀더 적합한 것으로 판단되었다. 개체목차원의 거리종속 경쟁지수중에서, 지위 및 흉고직경의 영향을 배제시킨다면 Hegyi의 경쟁지수가 흉고직경생장과 가장 밀접한 영향관계에 있는 것으로 밝혀졌다. 이로부터 Hegyi경쟁지수 및 임령, 우세목수고, 개체목의 흉고직경을 영향인자로 하는 다음과 같은 흉고직경생장식을 유도하였다. $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ 위의 식은 다른 조건이 같다면 지위지수는 흉고직경생장에 유리한 영향을 미치는 반면 임령 및 경쟁지수의 증가에 의해서는 흉고직경생장이 둔화된다는 일반생장법칙에 부합되어 흉고직경생장식으로 적합하다고 판단되며, 단목생장모델을 위한 함수식으로 활용될 수 있다.

• 한국치위생학회지
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• 제9권3호
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• pp.426-438
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• 2009

The purpose of this study was to examine the relationship of the general characteristics of dental patients to their total O'Leary index and individual plaque indexes in a bid to check the oral hygiene state of citizens and evaluate their plaque management ability. The subjects in this study were 288 patients at dental hospitals and clinics in Busan and South Gyeongsang Province. A survey was conducted from September to November 2008. The findings of the study were as follows: 1. Overall, the O'Leary index of the patients investigated stood at 72 percent. By age and gender, the O'Leary index was highest among those in their 30s(83%) and among the women(75%)(p<.05). As to the influence of toothbrushing frequency, the patients who did it twice or more a day had the highest O'Leary index(75%)(p<.001). By the use of oral hygiene supplies, the patients who used oral hygiene supplies had a higher O'Leary index(76%) than the others who didn't(p<.01). 2. As for plaque index for each tooth, 28 percent of their teeth were given zero point, and 52 percent were given one mark. 13 percent were given two marks, and 6.3 percent were given three marks. Thus, the teeth that were given one mark were largest in number(p<.001). 3. As for plaque index for labial posterior mandibular, 43 percent of their teeth were given one point, and 36 percent were given zero mark. 14 percent were given three mark, and 5 percent were given three marks(p<.01). 4. As for plaque index for buccal posterior maxilla, 57 percent of their teeth were given one point, and 20 percent were given zero mark. 16 percent were given two mark, and 6.3 percent were given three marks(p<.01). 5. As for plaque index for lingual posterior mandibular, 56 percent of their teeth were given one point, and 27.8 percent were given zero mark. 9 percent were given three mark and 6 percent were given three mark(p<.001).

• 한국지진공학회논문집
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• 제22권3호
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• pp.169-174
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• 2018

A total of 594 reservoirs (17%), which are managed by KRC, equipped with earthquake-resistant facilities whereas remaining ones did not. In addition, reservoirs were placed without the effect of geological structures (i.e., fault and lineament). Therefore, development on technique for alleviating the potential hazards by natural disasters along faults and lineaments has required. In addition, an effective reinforcement guideline related to the geological vulnerabilities around reservoirs has required. The final goal of this study is to suggest the effective maintenance for the safety of earth fill dams. A radius 2 km, based on the center of the reservoir in the study area was set as the range of vulnerability impacts of each reservoir. Seismic design, precise safety diagnosis, seismic influence and geological structure were analyzed for the influence range of each reservoir. To classify the vulnerability of geological disasters according to the fault distribution around the reservoir, evaluation index of seismic performance, precise safety diagnosis, seismic influence and geological structure were also developed for each reservoir, which were a component of the vulnerability assessment of geological disasters. As a result, the reservoir with the highest vulnerability to geological disasters in the pilot district was analyzed as Kidong reservoir with an evaluation index of 0.364. Within the radius of 100km from the epicenter of the Pohang earthquake, the number of agricultural infrastructure facilities subject to urgent inspections were 1,180 including reservoirs, pumping stations and intakes. Four reservoirs were directly damaged by earthquake among 724 agricultural reservoirs. As a result of the precise inspection and electrical resistivity survey of the reservoir after the earthquake, it was reported that cracks on the crest of reservoirs were not a cause of concern. However, we are constantly monitoring the safety of agricultural facilities by Pohang aftershocks.

• 한국병원경영학회지
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• 제25권4호
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• pp.1-12
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• 2020

During the COVID-19 pandemic, most of the western countries with advanced medical technology failed to contain coronavirus. This fact triggered our research question of what factors influence the clinical outcomes like infection rates and case mortality rates. This study aims to identify the determinants of COVID-19 related infection rates and case mortality rates. We considered three sets of independent variables: 1) socio-demographic characteristics; 2) cultural characteristics; 3) healthcare system characteristics. For the analysis, we created an international dataset from diverse sources like World Bank, Worldometers, Hofstede Insight, GHS index etc. The COVID-19 related statistics were retrieved from Aug. 1. Total cases are from 95 countries. We used hierarchical regression method to examine the linear relationship among variables. We found that obesity, uncertainty avoidance, hospital beds per 1,000 made a significant influence on the standardized COVID-19 infection rates. The countries with higher BMI score or higher uncertainty avoidance showed higher infection rates. The standardized COVID-19 infection rates were inversely related to hospital beds per 1,000. In the analysis on the standardized COVID-19 case mortality rates, we found that two cultural characteristics(e.g., individualism, uncertainty avoidance) showed statistically significant influence on the case mortality rates. The healthcare system characteristics did not show any statistically significant relationship with the case mortality rates. The cultural characteristics turn out to be significant factors influencing the clinical outcomes during COVID-19 pandemic. The results imply that the persuasive communication is important to trigger the public commitment to follow preventive measures. The strategy to keep the hospital surge capacity needs to be developed.

• 대기
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• 제25권2호
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• pp.323-337
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• 2015

This study explores the 6-month lead prediction skill of several climate indices that influence on East Asian climate in the GloSea5 hindcast experiment. Such indices include Nino3.4, Indian Ocean Diploe (IOD), Arctic Oscillation (AO), various summer and winter Asian monsoon indices. The model's prediction skill of these indices is evaluated by computing the anomaly correlation coefficient (ACC) and mean squared skill score (MSSS) for ensemble mean values over the period of 1996~2009. In general, climate indices that have low seasonal variability are predicted well. For example, in terms of ACC, Nino3.4 index is predicted well at least 6 months in advance. The IOD index is also well predicted in late summer and autumn. This contrasts with the prediction skill of AO index which shows essentially no skill beyond a few months except in February and August. Both summer and winter Asian monsoon indices are also poorly predicted. An exception is the Western North Pacific Monsoon (WNPM) index that exhibits a prediction skill up to 4- to 6-month lead time. However, when MSSS is considered, most climate indices, except Nino3.4 index, show a negligible prediction skill, indicating that conditional bias is significant in the model. These results are only weakly sensitive to the number of ensemble members.

• The Journal of Korean Physical Therapy
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• 제15권3호
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• pp.173-188
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• 2003

The two groups each consisting of 28 people who had an adult hemiplegia due to a brain injury received two different methods of exercises to reduce the angle to which the affected lower limb rotates externally. The comparisons between the two groups were made for the changes of the angle in external rotations measured between pre and post test. The static balance index values taken during pre and post tests were also compared. In addition, the correlations of the angle to which the affected lower limb rotates externally with static balance index values were analyzed. The result were as follows: 1. A statistical analysis indicated that in group one having taken simple R.O.M exercises, the angle to which the affected lower limb rotates externally and the static balance index values were both significantly different between pre and post test (P<.01). 2. A statistical analysis indicated that in group two having taken a pattern movement, both the angle to which the affected lower limb rotates externally and static balance index values were significantly different between pre and post test (P<.01). 3. A significant difference between simple R.O.M exercises group and pattern movement exercises groupwas shown only for the angle to which affected limb rotates externally not for static balance index values (P<.01), 4. Pearson correlation coefficient for the angle to which the affected limb rotates externally with static balance index values was found to be significant only in pattern movement exercises group (P < .05).