• The Korean Journal of Applied Statistics
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• v.27 no.7
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• pp.1097-1114
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• 2014

Multiple-life policies pay a benefit on the first death or the last death among the group of lives. In practice, the future lifetime random variable of policy holders has been considered to be independent, but it is more rational to take into account the correlations among the policy holders. In this paper, the Gaussian copula is applied to re ect the correlations among policy holders and then to diversify the common shock of the multiple life policies which follows an exponential distribution. Five case studies demonstrate its usefulness of using copula in calculating the premiums of the multiple-life policies including the common shock.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.651-680
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• 2015

In order to investigate vertical plant distribution on Namdeogyu of Mt. Deogyu National Park by temperature change, vascular plants of nine areas with 100-meter-high difference were surveyed from the Deogsangyo (650m alt.) to the Namdeogyusan (1,507m alt.). A total of 455 taxa belonging to 99 families, 280 genera, 402 species, 5 subspecies, 43 varieties, 4 forms and 1hybrid were vegetated on survey areas. Around 700 m high did species diversity of vascular plants decrease rapidly. The Detrended correspondence analysis (DCA) divided distribution of vascular plants into five groups; areas below 700m alt., 700~1,100m alt., 1,100~1,300m alt., and areas above 1,300m alt.. These results showed that vegetation of vascular plants on investigated areas has high correlation with climate elements of temperature. Vascular plants should be crowded within their own optimal ranges of vegetation. Climate change would result in shift of these distribution ranges, and thus vegetation shift will be happened accordingly.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.156-185
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• 2012

In order to investigate vertical plant distribution on Osaek valley of Mt. Seorak by temperature change, vascular plants of fourteen areas with 100-meter-high difference were surveyed from the Osaekgyo(345m alt.) to the Daecheongbong(1708m alt.). A total of 449 taxa belonging to 94 families, 279 genera, 397 species, 5 subspecies, 45 varieties, and 2 forma were vegetated on survey areas. Around 500 m high did species diversity of vascular plants decrease rapidly. The Detrended correspondence analysis(DCA) divided distribution of vascular plants into five groups; areas below 500m alt., 500~900m alt., 900~1400m alt., 1,400~1,600m alt., and areas above 1,600m alt.. These results showed that vegetation of vascular plants on investigated areas has high correlation with climate elements of temperature. Vascular plants should be crowded within their own optimal ranges of vegetation. Climate change would result in shift of these distribution ranges, and thus vegetation shift will be happened accordingly.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.680-707
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• 2010

In order to investigate vertical plant distribution on Jungsanri of Mt. Jirisan by temperature change, vascular plants of fourteen areas with 100-meter-high difference were surveyed from the Jungsan bridge(348 m alt.) to the Jangteumog(1653 m alt.). A total of 440 taxa belonging to 104 families, 287 genera, 385 species, 7 subspecies, 42 varieties, and 6 forma were vegetated on survey areas. Around 700 m high did species diversity of vascular plants decrease rapidly, but foreign species were not found. The Detrended correspondence analysis(DCA) divided distribution of vascular plants into five groups; areas below 500m alt., 500~600m alt., 600~1000m alt., 1000~1200m alt., and areas above 1200m alt.. These results showed that vegetation of vascular plants on investigated areas has high correlation with climate elements of temperature. Vascular plants should be crowded within their own optimal ranges of vegetation. Climate change would result in shift of these distribution ranges, and thus vegetation shift will be happened accordingly.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.693-697
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• 2007

지하수 함양량을 산정하기 위해서 유역물수지 모형 또는 지하수위 변동곡선법등이 활용되어 왔으며, 각각의 장단점에 대한 많은 논의가 있었다. 지역내의 지하수 관리계획을 위해서는 유역물수지 모형이 적합한 반면, 실제(actual) 함양량의 정확성 문제가 있으며, 지하수위 변동곡선법은 실제 지하수의 증감을 통해 실제 함양변화를 잘 표현하는 반면, 그 영향권이 관측공에 의해 제한된다는 단점이 있다. 이와 같은 두 방법의 장점을 살리고 단점을 보완하기 위해 본 연구에서는 유역유출모의와 지하수위 변동을 동시에 고려하여 지하수 함양량을 추정하는 방안을 제시하였다. 수문학적 과정으로 함양을 분석하기 위해 준분포형 수문모형인 SWAT과 완전분포형 지하수 유동해석 모형인 MODFLOW의 결합모형을 이용한 유역단위 유출해석을 수행한다. 실제로 하천변에 위치한 관측공에서의 지하수위는 하천유출시계열과 유사한 양상을 보이며, 상류 경사지에 위치한 관측공의 지하수위는 토양수의 지체와 감수현상을 나타내므로 이같이 시간적으로 상이한 지체 양상을 반영하기 위해 모형내의 비포화대를 통과하는 함양의 거동을 기존의 단일 저수지 모형에서 다단 저수지 모형으로 개선하고 지체함수와 관련된 매개변수를 보정함으로써 모의 함양 시계열과 관측 지하수위 시계열간의 상관성 분석을 수행할 수 있다. 아울러 모의 및 관측 지하수위 분포의 비교를 통해 공간적인 지하수 분포에 대한 검증을 수행함으로써 함양량 산정 절차가 완성된다. 이같은 일련의 절차는 기존의 유역물수지 모형과 지하수위 변동법을 동시에 고려한 새로운 방식의 지하수 함양량 산정기법으로 제시할 수 있을 것이다.성빈맥(1예), 저심박출증(3예), 재수술이 필요했던 출혈(2예), 흉골 지연봉합(2예), 급성 신부전(2예), 폐렴(1예), 대동맥내 풍선펌프로 인한 혈전색전증(1예),수술 후 섬망(2예) 등이 있었다. 생존한 10명의 환자들 중 1명을 제외한 나머지 9명의 환자에서 $38{\pm}40$개월간의 추적관찰이 되었는데, 추적 관찰 기간 중에 3명이 사망하였고 생존한 6명의 환자는 모두 양호한 상태(NYHA 기능등급, $I{\sim}II$)를 보였으며, 그 중 3명에서는 혈역학적으로 큰 의미가 없는 잔여단락이 있었다. 결론: 급성 심근경색증 후 심실중격 결손은 수술위험도가 높은 질환이지만, 수술 전 대동맥내 풍선펌프를 삽입하고 조기에 심실중격 결손부의 infarct exclusion 술식과 함께 관상동맥우회술을 시행함으로써 만족할 만한 수술 및 중기 결과를 얻을 수 있었다.출물 투여로 저하되었으나 NC군보다는 높게 나타났다. 간 중 중성지질 함량은 참나물 에탄올 추출물 투여 용량에 따른 유의차가 없었으나, 총콜레스테롤 함량은 고용량 병합투여한 HC-PBH군만 유의하게 저하되었다. 혈청 및 간 중의 지질 함량 변화는 정상식이를 급여한 NC군과 NC-PB군 간에는 유의차가 없었다. 따라서 고콜레스테롤식이를 급여하면서 참나물 에탄올 추출물을 병합투여 시에만 지질대사 개선 효과가 있는 것으로 여겨지며, 고용량 병합투여 시 효능이 더 큰 것으로 나타났다. 고콜레스테롤식이로 인한 산화적 스트레스가 고콜레스테롤혈증을 유발하였으며, 이는 참나물 에탄올 추출물에 함유된 항산화물질을 포함한 여러 생리활성물질

• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.224-230
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• 2005

Purpose: The maximal elastance ($E_{max}$) of myocardium has been established as a reliable load-independent contractility index. Recently, we developed a noninvasive method to measure the regional contractility using gated myocardial SPECT and arterial tonometry data. In this study, we measured regional $E_{max}(rE_{max}$ in the patients who underwent coronary artery bypass graft surgery (CABG), and assessed its relationship with other variables. Materials and Methods: 21 patients (M:F=17:4, $58{\pm}12$ y) who underwent CABG were enrolled. $^{201}TI$ rest/dipyridamole stress $^{99m}Tc$-sestamibi gated SPECT were performed before and 3 months after CABG. For 15 myocardial regions, regional time-elastance curve was obtained using the pressure data of tonometry and the volume data of gated SPECT. To investigate the coupling with myocardial function, preoperative regional $E_{max}$ was compared with regional perfusion and systolic thickening. In addition, the correlation between $E_{max}$ and viability was assessed in dysfunctional segments (thickening <20% before CABG). The viability was defined as improvement of postoperative systolic thickening more than 10%. Results: Regional $E_{max}$ was slightly increased after CABG from $2.41{\pm}1.64 (pre)\;to\;2.78{\pm}1.83 (post)$ mmHg/ml. $E_{max}$ had weak correlation with perfusion and thickening (r=0.35, p<0.001). In the regions of preserved perfusion (${\geq}60%$), $E_{max}$ was $2.65{\pm}1.67$, while it was $1.30{\pm}1.24$ in the segments of decreased perfusion. With regard to thickening, $E_{max}$ was $3.01{\pm}1.92$ mmHg/ml for normal regions (thickening ${geq}40%$), $2.40{\pm}1.19$ mmHg/ml for mildly dysfunctional regions (<40% and ${\geq}20%$), and $1.13{\pm}0.89$ mmHg/ml for severely dysfunctional regions (<20%). $E_{max}$ was improved after CABG in both the viable (from $1.27{\pm}1.07\;to\;1.79{\pm}1.48$ mmHg/ml) and non-viable segments (from $0.97 {\pm}0.59\;to\;1.22{\pm}0.71$ mmHg/ml), but there was no correlation between $E_{max}$ and thickening improvements (r=0.007). Conclusions: Preoperative regional $E_{max}$ was relatively concordant with regional perfusion and systolic thickening on gated myocardial SPECT. In dysfunctional but viable segments, $E_{max}$ was improved after CABG, but showed no correlation with thickening improvement. As a load-independent contractility index of dysfunctional myocardial segments, we suggest that the regional $E_{max}$ could be an independent parameter in the assessment of myocardial function.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6852-6859
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• 2015

The purpose of this study was to determine the growth characteristics and distribution pattern of a brackish water clam Corbicula japonica in Seomjin River. Field samples were taken from 14 stations with salinity gradients during spring. Salinity at the bottom layer ranged from 1.0 psu to 32.9 psu, with low salinities in the upper area of the river. In particular, salinity at St.11 was decreased drastically to be ca. 15.0 psu, indicating an intermediate salinity zone. The distribution pattern of C. japonica was related to the salinity gradient, with the highest densities of $2,102ind.m^{-2}$ at Station 13, followed by $1,507ind.m^{-2}$ at Station 11. Here, we focused on the growth characteristics of collected C. japonica collected at two stations with different salinity values. The relationship between shell length and total weight was highly correlated ($R^2=0.91$, P<0.001) at Station 13 compared to that at Station 11 ($R^2=0.72$, P<0.001). On the other hands, the degree of correlation between shell length and shell height (SH) or shell width (SW) at Station 11 (SH: $R^2=0.91$, P<0.001; SW: $R^2=0.69$, P<0.001) was higher than that at Station 13 (SH: $R^2=0.64$, P<0.001; SW: $R^2=0.48$, P<0.001). In addition, fatness index of C. japonica at Station 13 was significantly (P < 0.001) higher than that at St. 11 (t-test value=-22.8, p<0.001). This implies that C. japonica at Station 13 might have enhanced their somatic growth, whereas C. japonica at Station 11 might have this kind of defense mechanism their internal organization against the salinity stress. Ecologically, this kind of defense mechanism of C. japonica against salinity flucuation may play an important role in their survival strategy.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.345-353
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• 2018

Hibernation is regarded as a physiological and behavioral adaptation that permits the survival of animals such as bats during seasonal periods of energy shortage. This study investigated the hibernation period of Plecotus ognevi in the temperate climate zone and the relationship between the thermal preference and hibernating process of bats. We hypothesized that the hibernation period of bats is closely related to the external temperature and temperature preference of bat species in the temperate region. To verify this hypothesis, we surveyed the distribution of the P. ognevi population in South Korea, and the temperature preference and the characteristics of hibernacula of P. ognevi. We predict that hibernation in the bat will begin when the external temperature drops below the thermal preference of the species and will leave from hibernation when the external temperature is higher than the thermal preference. P. ognevi hibernated in roosts maintained in low temperature ambient conditions with $-3.5{\sim}7.5^{\circ}C$). The body temperatures (averaged $3.01{\pm}1.30^{\circ}C$, ranged $0.1{\sim}7.8^{\circ}C$) of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. The bats began to hibernate in late November and final arousals occurred in mid-March, so that the total length of the hibernation was 115~120 days. The period of hibernation was strongly influenced by fluctuations in the external mean temperature. This study suggests that the onset and termination of P. ognevi hibernation is due to the interaction between the temperature of the hibernacula and that of the external environment and is based on the thermal preference of the bats. The study also suggests that the hibernation strategy such as thermal preference and hibernation periods of this species affect to distribution as bat species adapting to a severely climate.

• Korean Journal of Remote Sensing
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• v.15 no.3
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• pp.195-208
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• 1999

In the classification of satellite images, the representative of training of classes is very important factor that affects the classification accuracy. Hence, in order to improve the classification accuracy, it is required to optimize pre-classification stage which determines classification parameters rather than to develop classifiers alone. In this study, the normality of training are calculated at the preclassification stage using SPOT XS and LANDSAT TM. A correlation coefficient of multivariate Q-Q plot with 5% significance level and a variance of initial training are considered as an object function of genetic algorithm in the training normalization process. As a result of normalization of training using the genetic algorithm, it was proved that, for the study area, the mean and variance of each class shifted to the population, and the result showed the possibility of prediction of the distribution of each class.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.85-91
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• 2000

Purpose : The aim of this study is to look for the possible efficacy of postoperative external irradiation for incompletely resected meningiomas. Methods and Materials : From August 198: to January 1997, forty-four patients with intracranial meningioma were treated by postoperative external irradiation. Of the 44 meningiomas, 18 transitional, 13 meningotheliomatous, 6 hemangiopericytic, 4 atypical, 2 fibroblastic and 1 malignant meningioma were identified. We classified all patients into two groups by the histology. The benign group was consisted of the meningotheliomatous, transitional and fibroblastic types. The malignant group was consisted of the atypical, hemangiopericytic and malignat types. In the means of surgery, 37 patients were resected incompletely and 7 patients were managed by biopsy only. After surgery, all patients were received postoperative external irradiation. Radiotherapy was deliverd using Co-60 or 4 MV photon beam to a total dose of 50 to 65 Gy (mean dose 57.4 Gy) with a 1.8 to 2 Gy per fraction. The median follow-up was 48 months (range : 21 $\~$ 101 months). Multivariate analysis of the Influence by age, sex, location, histology and radiation dose on local control has been done using Cox's proportional hazard model. Results : 5-year local control rate was 93.8$\%$ for the benign histology and 51.8$\%$ for the malignant histology (p=0.0110) and overall local control rate at 5 years was 87.4$\%$. The analysis of the prognostic factors, such as age, sex, location, and radiation dose were not significant except for the histology. Conclusion : Adjuvant postoperative external irradiation appears to be significantly improved local control in the patients with incompletely resected meningiomas.