• Title/Summary/Keyword: Sampling Period

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Comparative Study of the Discrimination of Uni-variate Analysis and Multi-variate Analysis for Small-Business Firm's Fail Prediction (중소기업 부실예측을 위한 단일변량분석과 다변량분석의 판별력 비교에 관한 연구)

  • Moon, Jong-Geon;Ha, Kyu- Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4881-4894
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    • 2014
  • This study selected 83 manufacturing firms that had been delisted from the KOSDAQ market from 2009 to 2012 and the sample firms for the two-paired sampling method were compared with 83 normal firms running businesses with same items or in same industry. The 75 financial ratios for five years immediately before delisting were used for Mean Difference Analysis with those of normal firms. Fifteen variables assumed to be significant variables for five consecutive years out of the analysis were used to in the Dichotomous Classification Technique, Logistic Regression Analysis and Discriminant Analysis. As a result of those three analyses, the Logistic Regression Analysis model was found to show the greatest discrimination. This study is differentiated from previous studies as it assumed that the firm's failure proceeded slowly over long period of time and it tried to predict the firm's failure earlier using the five years' historical data immediately before failure, whereas previous studies predicted it using three years' data only. This study is also differentiated from the proceeding comparative studies by its statistically complex Multi-Variate Analysis and Dichotomous Classification Analysis, which general stakeholders can easily approach.

Development of Western Cherry Fruit Fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), after Overwintering in the Pacific North West Area of USA (미국 북서부지역에 발생하는 서부양벚과실파리의 발생 월동 후 발생 동태에 관한 연구)

  • Song, Yoo-Han;Ahn, Kwang-Bok
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.4
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    • pp.217-227
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    • 2007
  • The western cherry fruit fly, Rhagoletis indifferens Curran (Diptera:Tephritidae), is the most important pest of cultivated cherries in the Pacific Northwest area of the United States, being widely distributed throughout Oregon, Washington, Montana, Utah, Idaho, Colorado and parts of Nevada. The control of R. indifferens has been based on calendar sprays after its first emergence because of their zero tolerance for quarantine. Therefore, a good prediction model is needed for the spray timing. This study was conducted to obtain the empirical population dynamic information of R. indifferens after overwintering in the major cherry growing area of the Pacific Northwest of the United States, where the information is critically needed to develop and validate the prediction model of the fruit fly. Adult fly populations were monitored by using yellow sticky and emergence traps. Larvae growth and density in fruits were observed by fruit sampling and the pupal growth and density were monitored by pupal collection traps. The first adult was emerged around mid May and a large number of adults were caught in early June. A fruit had more than one larva from mid June to early July. A large number of pupae were caught in early July. The pupae were collected in various period of time to determine the effect of pupation timing and the soil moisture content during the winter. A series of population density data collected in each of the developmental stage were analyzed and organized to provide more reliable validation information for the population dynamic models.

Characteristics of tamiflu occurrence in surface water using LC/MS/MS (LC/MS/MS를 이용한 하천수 중 항바이러스제 타미플루 잔류 특성)

  • Shin, Sun-Kyoung;Kang, Young-Yeul;Park, Jin-Soo;Koo, So-Hyun;Hwang, Seung-Ryul;Kim, Woo-Il;Song, Ki-Bong;Kim, Young-Hee;Kim, Tae-Seung;Han, Jin-Suk
    • Analytical Science and Technology
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    • v.23 no.2
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    • pp.147-154
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    • 2010
  • Oseltamivir carboxylate (OC) and Oseltamivir ethylester (OE) were analyzed to evaluate the environmental distribution in pandemic season in Korea. The detected concentration of OE was the range of $0.008\sim0.087\;{\mu}g/L$, and OC was the range of $0.029\sim0.287\;{\mu}g/L$. The detected concentration of OC in this study was two times higher than reported concentration of OC in river water in Japan. But, these analytical results cannot be directly compared to the previous reported concentration, because of the different sampling period.

Influences of Thermal Effluents on the Epilithic Algal Community in Small Stream Originating from the Seokjung Hot Spring (온천 배수 유입에 따른 소형 하천의 생태계 변화와 회복에 관한 연구 -소형 하천에서 온천 배수가 부착조류 군집에 미치는 영향)

  • 정연태;문연자;김미연;최민규;길봉섭
    • Korean Journal of Environmental Biology
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    • v.17 no.3
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    • pp.345-358
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    • 1999
  • To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58% of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.

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Phytoplankton and Environmental Factors in Lake Hwaong (화옹호의 식물플랑크톤과 환경요인)

  • Chung, Mi-Hee;Kim, Ho-Sub;Choi, Chung-Il;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.37 no.2 s.107
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    • pp.193-204
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    • 2004
  • This study was conducted to evaluate both temporal and spatial dynamics of phytoplankton community and environmental parameters in a newly made reclaimed esturine lake (L. Hwaong). Monthly sampling was conducted at 4 sites covering the longest transect of longitudinal gradient of the lake from June to November, 2002. Total 5 classes 8 orders 26 families 83 genus 192 species were identified at all study sites during the study period. Phytoplankton total cell density ranged 24${\sim}$ 1,882 cells $mL^{-1}$ and highly varied both temporally and spatially. Total cell density was significantly related with salinity, pH, BOD, COD, SS, TN and TP concentration. Diatom density also was significantly correlated with salinity, SS, BOD, COD and TN concentration, Although there was spatial difference, a longtudinal gradient appeared in phytoplankton cell density, Chl-a, TN and TP concentration from the mouth of river in June and August. In conclusion, phytoplakton community structure was dominated by diatoms (Bacillariophyceae), and appeared to be largely influenced by salinity, precipitation, and nutrients during the summer and the fall.

Analysis of Ecological Health Using a Water Quality and Fish in Bocheong Stream (보청천의 수질 및 어류를 이용한 생태학적 건강도 분석)

  • Ryu, Tae-Ho;Kim, Yu-Pyo;Kim, Jin-Kyu;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.255-262
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    • 2010
  • This study was conducted at 5 sites of Bocheong Stream basin in May and September 2009 for the evaluate of fish assemblage and chemical water quality. For the study, the models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) were modified as 8 and 11 metric attributes, respectively. We also analyzed patterns of chemical water quality at the sampling site over the period of 2005~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. The survey showed that total sampled fishes were 34 species and the most dominant species was Zacco platypus (24.3%). In Bocheong Stream basin, values of IBI averaged 28 (n=5), which is judged as a "Good". IBI score at B1, B4 and B5 indicating a "Good" condition whereas, B2 and B3 were as 21 and 22, indicating "Fair" condition, respectively. QHEI was 152 (n=5), judged as "Fair" habitat condition. Values of BOD and COD averaged 1.0 $mgL^{-1}$ (scope: 0.3~4.0 $mgL^{-1}$) and 2.3 $mgL^{-1}$ (scope: 0.3~18.7 $mgL^{-1}$), respectively. Total nitrogen (TN), total phosphorus (TP) and suspended solid (SS) were distinct spatial variation. Based on the IBI, QHEI and chemical water quality dataset, ecological health of Bocheong Stream basin was evaluated that generally good.

The Fish Fauna and Community of Chogang Stream, Korea (초강천의 어류상과 군집)

  • Hur, Jun-Wook;Park, Jin-Woo;Kim, Jeong-Kon
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.271-278
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    • 2010
  • Field monitoring was conducted for fish fauna and community assessment at 7 sites from April 2008 to October 2009 in the Chogang Stream. The number of fish samples in this period were 4,669 in 36 species of 9 families. Family Cyprinidae take 66.7 (24 species), Cobitidae, Bagridae, Centropomidae and Odontobutidae occupied 5.6%(each 2 species), respectively. Twenty species (55.6%) including Acheilognathus koreensis and A. yamatsutae were found endemic out of the 36 species. The species of Pseudopungtungia nigra, Gobiobotia macrocephala and Gobiobotia brevibarba were endangered species. The most frequently found one was Zacco koreanus (34.0%, n=1,588) followed by Z. platypus (22.6%, n=1,053) and Coreoleuciscus splendidus (13.3%, n=623). The lower reach of Chogang Stream was more abundance of species, high diversity, evenness and richness, and lower dominance index than those of the upper reach. According to the dendrogram established at 0.5 level of similarity rate, sampling stations were divided into 3 groups. They were divided into upper most stream (St. 1~St. 2), upper stream (St. 3), middle and lower stream (St. 4~St. 7). Overall, it was concluded that the Chogang Stream has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

Expanding Health Education Plan For Improving Public Health (국민건강증진을 위한 보건교육확대방안에 관한 연구)

  • Yun, Gi-Seon;Park, Chung-Yeol
    • The Journal of the Korea Contents Association
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    • v.15 no.3
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    • pp.303-317
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    • 2015
  • Although the public health centers have been initiating health education recently, it is not extending as expected and the participation of the program is low. The reason is that the office workers have few opportunities to receive health education since there are few public health centers in relation to the population. Much time is required for travel and attendance of the classes. In order to solve this problem, the aim is to increase participation in health education, improve the overall public health awareness, expand the number of health education locations to reduce medical expenses, vitalize the lifelong educational health programs, and improve the national health insurance. In order to research about the health education expansion plan for public health improvement, a study focused on men and women above age 20 who need health education. The research sample was selected through random sampling that targeted people who participated in the health programs or the health education. The period of this survey was from September 1st to September 30th, 2014. A total of 509 participants completed the survey data for the actual analysis to propose the health education expansion plan for the public health improvement.

Community Structure of Fisheries Resources Caught by Dredge in the Uljin Marine Ranching Area, Korea (울진바다목장에서 형망으로 어획된 수산자원의 군집구조)

  • Yoon, Byoung Sun;Park, Jeong-Ho;Yoon, Sang Chul;Yang, Jae Hyeong;Sohn, Myoung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.935-944
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    • 2014
  • To elucidate the variation of species composition, biomass and size distribution of fishery resource in the Uljin marine ranching area was investigated at the 4 stations from 2009 to 2010 based on the dredge sampling. During the survey period, a total of 41 fishery resource species were sampled with a mean density of $2,554,633\;ind./km^2$ and mean biomass was $32,946kg/km^2$. A total 36 fishery resource species were sampled with a mean density of $3,198,793\;ind./km^2$ and mean biomass $41,177kg/km^2$ in 2009 and it were sampled a total 31 species, mean $1,910,473kg/km^2$ and $24,716kg/km^2$ in 2010. The major individual-dominant species, occupying over 1% of total individuals, were Gomphina veneriformis (2,491,818 ind., 82.2%), Umbonium costatum (221,973 ind., 8.7%), Mactra chinensis (49,879 ind., 2.0%), Glossaulax didyma hayashii (49,879 ind., 1.9%), Blepharipoda liberate (37,714 ind., 1.5%) and Paguridae spp. (27,266 ind., 1.1%). The major biomass-dominant species, occupying over 1% of total biomass, were G. veneriformis (25,124 kg, 76.3%), G. didyma hayashii (2,596 kg, 7.9%), M. chinensis (2,024 kg, 6.1%), Ovalipes punctatus (921 kg, 2.8%) and Glossaulax didyma didyma (567 kg, 1.7%). From the cluster analysis based on Bray-Curtis similarity matrix of fourth root transformed data of species number and individuals was divided into 2 different groups of the fishery resource community (Group A-St.1, Group B-Sts. 2, 3, 4). The 2009 and 2010 mean Shell length (mm) of G. veneriformis was 37.73 mm, 29.76 mm and M. chinensis was 62.03 mm, 44.94 mm, respectively.

Sensitivity Analysis of Input Parameters for a Dynamic Food-Chain Model DYNACON (동적섭식경로모델 DYNACON에 대한 입력변수의 민감도분석)

  • Hwang, Won-Tae;Lee, Geun-Chang;Han, Moon-Hee;Cho, Gyu-Seong
    • Journal of Radiation Protection and Research
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    • v.25 no.1
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    • pp.11-19
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    • 2000
  • The sensitivity analysis of input parameters for a dynamic food chain model DYNACON was conducted as a function of deposition date for the long-lived radionuclides $(^{137}Cs,\;^{90}Sr)$. Also, the influence of input parameters for the short and long-terms contamination of selected foodstuffs (cereals, leafy vegetables, milk) was investigated. The input parameters were sampled using the LHS technique, and their sensitivity indices represented as PRCC. The sensitivity index was strongly dependent on contamination period as well as deposition date. In case of deposition during the growing stages of plants, the input parameters associated with contamination by foliar absorption were relatively important in long-term contamination as well as short-term contamination. They were also important in short-term contamination in case of deposition during the non-growing stages. In long-term contamination, the influence of input parameters associated with foliar absorption decreased, while the influence of input parameters associated with root uptake increased. These phenomena were more remarkable in case of the deposition of non-growing stages than growing stages, and in case of $^{90}Sr$ deposition than $^{137}Cs$ deposition. In case of deposition during growing stages of pasture, the input parameters associated with the characteristics of cattle such as feed-milk transfer factor and daily intake rate of cattle were relatively important in contamination of milk.

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