• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.82-89
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• 2005

The purpose of this paper is to investigate index numbers by conducting various comparisons among the widely used index formulas. The comparison is considered in three ways; 1) divergences in the magnitudes of index numbers due to the use of different formulas (Laspeyres, Paasche, Fisher, and Tornqvist); 2) the effect of selection of base year (fixed-year base vs. chain-type); 3) the degree of approximation of indirect to direct quantity index. The empirical application is to sawmills and planing mills industry of U.S. using a national time series data covering years of 1948-2000. The results show that the differences between Laspeyres and Paasche index can be substantial in some cases while the difference between Fisher and Tornqvist index is minimal. We also confirm that the selection of base year can cause significant divergences, especially when the variables undergo rapid price or quantity changes over time. We find that indirect quantity index approximates direct quantity index reasonably well in U.S. sawmill industry.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.19-22
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• 2006

To prepare basic data for oral health promotion of high school students through the survey of the recognition of oral health, a questionnaire survey was conducted for 369 students. Statistical analysis was conducted using the SPSS 11.5 with $x^2$-test, fisher's exact test, t-test. The obtained results were as follows 1. The average of the high school student's DMF rate, DMFT index and SiC Index was 87.53%, 3.36, 6.50. 2. The average of the high school student's oral health knowledge was more than 3, 70% of highschool did right toothbrushing. But toothbrushing frequency of student of more than 60% was less than 2 a day. 3. In SiC Index, Only 30% of high school students received oral health education and 80% of them recognized oral health manpower's education needs.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.9-13
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• 1987

K-emans alsor/thm was used to classify cloud-type that is low, mix and cumuionimbus Tnitiat ciustercenters and K parameter is given in this paper by coatse computins and Fisher’s alsorithm. Results indicate that performance index is minimized and mix cloud is well clallified.

• Geomechanics and Engineering
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• v.13 no.5
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• pp.861-879
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• 2017

Coal and gas outburst is a serious dynamic disaster that occurs during coal mining and threatens the lives of coal miners. Currently, coal and gas outburst is commonly predicted using single indicator and its critical value. However, single indicator is unable to fully reflect all of the factors impacting outburst risk and has poor prediction accuracy. Therefore, a more accurate prediction method is necessary. In this work, we first analyzed on-site impacting factors and precursors of coal and gas outburst; then, we constructed a Fisher discriminant analysis (FDA) index system using the gas adsorption index of drilling cutting ${\Delta}h_2$, the drilling cutting weight S, the initial velocity of gas emission from borehole q, the thickness of soft coal h, and the maximum ratio of post-blasting gas emission peak to pre-blasting gas emission $B_{max}$; finally, we studied an FDA-based multiple indicators discriminant model of coal and gas outburst, and applied the discriminant model to predict coal and gas outburst. The results showed that the discriminant model has 100% prediction accuracy, even when some conventional indexes are lower than the warning criteria. The FDA method has a broad application prospects in coal and gas outburst prediction.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.53-63
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• 2006

The objective of this study is to estimate Korean transportation service index (KTSI), and to explore possible uses of the KTSI. The KTSI was monthly index to represent the level of passenger and freight services by road, railroad, air and maritime modes, which was developed from eight series. Four of these series measure the level of passenger services (passenger-kilometers) by road, railroad. air and maritime modes : monthly data from January 1995 to December 2004. Similarly. the remaining four series measure the level or freight activity (tonnage) by four modes during the same period. Given the weights of modal revenues, component series were aggregated into two indexes (passenger index and freight index) and a composite index using Chained Fisher Ideal index. which was a geometric mean of the Laspeyres index and the Passche index. The Fisher Ideal index is one of the 'superlative' indexes, which diminish 'substitution bias' as current-weighted indexes. As a result, the freight index and the composite index explain economic conditions better than the passenger index. Based on the composite index. the newly estimated KTSI shows an average lag time of one and a half years at peaks and three months at troughs in comparison with domestic business cycles. Nonetheless. the following efforts are needed for more credible and useful estimates; establishment of data collection scheme in time. credibility uplift of used data, development of various indexation methods.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.108-119
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• 2021

We aimed to develop a naturalness index for forest-dwelling birds in four national parks in Korea and to simulate the effect of species loss on this naturalness index. Five bird specialists were asked to give 112 bird species a disturbance susceptibility score (DSS), and the naturalness index was calculated based on this. The 112 bird species represented 8 orders (Cuculiformes, Piciformes, Accipitriformes, Falconiformes, Columbiformes, Caprimulgiformes, Strigiformes, and Passeriformes). DSS was the highest for Terpsiphone atrocaudata and Pitta nympha, and lowest for Pica pica, Hypsipetes amaurotis, and Streptopelia orientalis. There was a significant negative relationship between a species' population number and its DSS. Among the four national parks, Mt. Songni had the highest naturalness index, followed by Mt. Wolak, Mt. Juwang, and Mt. Wolchul. We investigated the change in biodiversity indices under four scenarios, which assumed the extinction of species with less than 5 (Scenario 1), 10 (Scenario 2), 50 (Scenario 3), and 100 individuals (Scenario 4). The results showed that although all biodiversity indices decreased as the species loss increased, they all behaved differently. Fisher's alpha diversity decreased as the number of species proportionally decreased. There was almost no change in Shannon-Wiener H' index in Scenarios 1 and 2. The naturalness index showed increased sensitivity in Scenarios 1 and 4. Our future aims are to obtain the DSS for all forest-dwelling bird species, and to adopt the naturalness index to evaluate temporal and spatial changes in biodiversity.

• Journal of Korean Neurosurgical Society
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• v.30 no.12
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• pp.1375-1380
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• 2001

Objective : The authors analyzed the incidence, the cause and the prognosis of hydrocephalus following aneurysmal subarachnoid hemorrhage to evaluate the risk factors of hydrocephalus and to provide the proper treatment method for hydrocephalus following aneurysmal subarachnoid hemorrhage. Methods : The 505 cases of subarachnoid hemorrhage followed by aneurysmal surgery from January 1990 to May 1999, were divided into shunt group and shunt-free group and we were reviewed for the clinical status, Fisher's grade, brain CT findings and prognosis. Results : The incidence of acute hydrocephalus was 37.2% of patients and 18.9% to developed chronic hydrocephalus. Shunt surgery due to chronic hydrocephalus was required in 6.5% of patients. We found following variables were significantly related to shunt-dependent hydrocephalus : high Hunt-Hess and Fisher grade, initial CT findings of intraventricular hemorrahge, posterior circulation aneurysm, preoperative rebleeding, delayed ischemic deficits, and initial high ventricular size index. There were no statistically significant relationships between shunt-dependent hydrocephalus and patient age or sex, timing of operation. The previous hypertension was not related to shunt dependent hydrocephalus. Prognosis in shunt group showed poor result. Conclusion : The risk factors of hydrocephalus following aneurysmal subarachnoid hemorrhage are high Hunt-Hess grade, high Fisher's grade, aneurysms of posterior circulations, preoperative aneurysmal rebleeding, delayed ischemic deficits, initial CT findings of intraventricular hemorrahge and initially increased ventricular size. The patients with these factors should the carefully observed and managed accordingly due to poor prognosis related to hydrocephalus requiring shunt operation.

• The Korean Journal of Ecology
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• v.7 no.4
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• pp.208-232
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• 1984

A survey was conducted on the vegetation of Seogmo island, which is small island (ca. 41 okm2) located about 1km west of Kanghwa island in the central Korea, from Aug. 1983 to May 1984. Based on the field data, actual vegetation map and potential natural vegetation map were made. The island is covered with broad-leaved trees dominated with Quercus variabilis. The dominance diversity curves obtaiend in different associations are grouped in two types, lognormal distribution forms at the undisturbed vegetation and geometric series at the disturbed or rocky sites. It seems that the curves show to us the nature of their ecocline by the hypothesis of some investigators, i.e. Random niche boundary hypothesis, niche preemption hypothesis, lognormal distribution and logarithmic series. Total numbers of vascular plant species of the island were recorded 108 families, 348 genera, 475 species, 73 variaties and 7 forma. And Pte.-Q Index, 0.93, and Fisher's Index, 589.8, were higher than those in neighboring islands.

• The Korean Journal of Ecology
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• v.10 no.2
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• pp.53-62
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• 1987

Floristic composition and vertical distribution of Mt. Daedun (western slope) were investigated from 1985 to 1986. The results are as follows; 108 families, 346 genera, 511 species, 2 subspecies, 75 varieties, 5 forma or 593 taxa including 77 cultivars. The floral data showed the ecological characteristics such as the value 346 in Fisher's Index, H-D1-H5 in biological type, 10.9% in urban index of naturalized plants and 60.5% in erect form growth form. Based on the physiognomy and population density of dominant tree species the forest vegetation of Mt. Daedun (western slope) was classified into 5 types; Quercus mongolica forest and Q. variabilis forest at 800m above, Carpinys laxiflora forest and Acer mono forest at 700m to 800m and Sapium japonicum forest at 500m to 800m in altitude. And Lindera erythrocarpa forest and zelkova serrata forest are widely distributed at 400m to 800m in altityde along valley and at mountain foot area.

• Journal of Korean Neurosurgical Society
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• v.62 no.6
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• pp.643-648
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• 2019

Objective : Shunt-dependent hydrocephalus (SdHCP) is a well-known complication of aneurysmal subarachnoid hemorrhage (SAH). The risk factors for SdHCP have been widely investigated, but few risk scoring systems have been established to predict SdHCP. This study was performed to investigate the risk factors for SdHCP and devise a risk scoring system for use before aneurysm obliteration. Methods : We reviewed the data of 301 consecutive patients who underwent aneurysm obliteration following SAH from September 2007 to December 2016. The exclusion criteria for this study were previous aneurysm obliteration, previous major cerebral infarction, the presence of a cavum septum pellucidum, a midline shift of >10 mm on initial computed tomography (CT), and in-hospital mortality. We finally recruited 254 patients and analyzed the following data according to the presence or absence of SdHCP : age, sex, history of hypertension and diabetes mellitus, Hunt-Hess grade, Fisher grade, aneurysm size and location, type of treatment, bicaudate index on initial CT, intraventricular hemorrhage, cerebrospinal fluid drainage, vasospasm, and modified Rankin scale score at discharge. Results : In the multivariate analysis, acute HCP (bicaudate index of ${\geq}0.2$) (odds ratio [OR], 6.749; 95% confidence interval [CI], 2.843-16.021; p=0.000), Fisher grade of 4 (OR, 4.108; 95% CI, 1.044-16.169; p=0.043), and an age of ${\geq}50years$ (OR, 3.938; 95% CI, 1.375-11.275; p=0.011) were significantly associated with the occurrence of SdHCP. The risk scoring system using above parameters of acute HCP, Fisher grade, and age (AFA score) assigned 1 point to each (total score of 0-3 points). SdHCP occurred in 4.3% of patients with a score of 0, 8.5% with a score of 1, 25.5% with a score of 2, and 61.7% with a score of 3 (p=0.000). In the receiver operating characteristic curve analysis, the area under the curve (AUC) for the risk scoring system was 0.820 (p=0.080; 95% CI, 0.750-0.890). In the internal validation of the risk scoring system, the score reliably predicted SdHCP (AUC, 0.895; p=0.000; 95% CI, 0.847-0.943). Conclusion : Our results suggest that the herein-described AFA score is a useful tool for predicting SdHCP before aneurysm obliteration. Prospective validation is needed.