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Overview of Major Oil Spill at Sea and Details of Various Response Actions -1. Number and Volume of Marine Oil Spills in Korea and in the World (대형 기름유출사고와 방제조치에 관한 연구 -1. 국내외 해양기름오염사고 건수와 유출량)

  • Kim, Kwang-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.2
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    • pp.129-137
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    • 2013
  • In order to obtain quantitative basic data for marine oil pollution prevention, the statistics of oil spill incidents in Korea and in the world for 20 years from 1993 to 2012 were collected and analyzed with relation to the number of oil spills and the amount of oil spilt. In Korea for 20 years, total number and average annual number of oil spills were 6,608 cases and nearly 330 cases/year, respectively, and total volume and average annual volume of oils spilt were 57,328 kL and nearly 2,866 kL/year, respectively. Due to major oil spills from oil tankers, annual volumes of oils spilt in Korea were sharply increased to 15,388 kL in 1993, 15,773 kL in 1995, 3,428 kL in 1997 and 13,008 kL in 2007. In case of worldwide oil spills for 20 years, total number and average annual number of oil spills of 8 kL (or 7 tonnes) and above were 420 cases and 21 cases/year, respectively, and total amount and average annual amount of oils spilt 8 kL (or 7 tonnes) and above were about 800,000 kL (or 704,000 tonnes) and about 40,000 kL/year (or 35,200 tonnes/year), respectively. Major oil spills from oil tankers increased massively annual amounts of oils spilt worldwide to about 159,000 kL (or 140,000 tonnes) in 1993, about 147,600 kL (or 130,000 tonnes) in 1994, about 90,900 kL (80,000 tonnes) in 1996, about 81,800 kL (72,000 tonnes) in 1997 and about 76,100 kL (or 67,000 tonnes) in 2002. Obvious correlation between annual number of oil spills and annual amount of oil spilt was not found in both Korea and the world, while both annual number and annual volume tended to decrease with the lapse of year in both Korea and the world, though there were wide fluctuations from year to year in both annual number of oil spills and annual amount of oils spilt worldwide and in Korea for 20 years. From 2008 to 2012 worldwide, there were sharp decreases in both annual number and annual amount of oil spills. In particular, no oil spill of 800 kL (or 700 tonnes) and above occurred in the year of 2012.

Change of Germination Rate for Chili Pepper and Chinese Cabbage Seed in Relation to Packaging Materials and Storage Conditions over 10 Years (보관용기 및 저장조건에 따른 고추 및 배추종자의 10년간 발아율 추이)

  • Soh, Eun Hee;Lee, Woo Moon;Park, Kee Woong;Choi, Keun Jin;Yoon, Moo Kyoung
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.864-871
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    • 2014
  • Seed viability is affected by storage conditions and rapid loss of viability in storage is the major cause for low germination. This study was carried out to examine the effect of packaging materials and storage temperature on seed germination rate over 10 years in two species (Capsicum annuum L. and Brassica rapa L. ssp. pekinensis) and determine effective storage conditions for maintaining seed viability. Seeds were packaged in aluminum poly pouches under vacuum, polyethylene bottles, and paper bags containing silica gel and stored under one of two controlled conditions ($15^{\circ}C$, RH 40% or $5^{\circ}C$, RH 30%) or at ambient condition. Seed germination was recorded at 6-month intervals for 10 years. The seeds of both species showed no decline in viability until 6.5 years at 15 or $5^{\circ}C$, irrespective of packaging materials. However, under ambient conditions, the seeds of chili pepper and Chinese cabbage in paper bags lost viability after 4 and 5 years, respectively. By contrast, seeds of both species in vacuum-aluminum poly pouches exhibited a 99% germination rate after 6 years under ambient conditions. Pepper seeds in the vacuum-aluminum poly pouches maintained a 93% germination rate after 10 years in ambient conditions. These results indicated that a special seed storage facility for maintaining viability of chili pepper and Chinese cabbage seed might not be essential and seed testing would not be necessary for 10 years, if chili pepper and Chinese cabbage seeds were packed in ambient/vacuum-aluminum poly pouches or $5^{\circ}C$/vacuum-aluminum poly pouches.

The Characteristics of Heavy Metal Accumulations in Feral Pigeon (Columba livia) Feathers for Environmental Monitoring (환경모니터링을 위한 집비둘기 깃털의 중금속 축적특성 연구)

  • Lee, Jangho;Lee, Jongchun;Lee, Sang Hee;Kim, Myungjin;Lee, Eugene;Han, Areum;Shim, Kyuyoung
    • Journal of Environmental Impact Assessment
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    • v.23 no.6
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    • pp.492-504
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    • 2014
  • Feral pigeon (Columba livia) has been known as a good indicator for accumulations of chemical pollutants in urban areas. However, it is against the animal rights to kill the indicator species in order to monitor pollutants accumulations in wild birds. Eggs and feathers of birds, therefore, have been used as non-invasive monitoring materials. Even though eggs are a good indicator for accumulations of lipophilic pollutants, but unsuitable for some heavy metals such as lead and cadmium because bird's ovary builds a sort of barrier to inhibit higher accumulations of some heavy metals in the eggs. Therefore, feathers instead of eggs have been used as a non-invasive indicator for accumulations of heavy metals. However, there are few studies of heavy metal accumulations of feral pigeon in Korea. In this study, we characterized the characteristics of heavy metal accumulations of feathers in relation to internal organs (bloods, viscera and bones) in feral pigeons between two sites (Hangang Park representing urban area and Hampyeong Park for rural area). The samples from the Hangang Park showed significantly higher lead (Pb) concentrations in the blood, liver and bone than those from Hampyeong Park. The Pb concentration in the feathers was also significantly higher at Hangang Park than at Hampyeong Park. The analytical result for the breast, wing and tail feathers, and the internal organs (blood, lung, liver, kidney and bone) indicated that the Pb concentrations in the feathers were significantly positively correlated with the levels in the kidney and bone. Overall, feathers of feral pigeon may be candidate for bioindicator to monitor for Pb accumulations in urban areas.

Effect of Visual Sensory Improvement by Amblyopia Treatment on Improvement of Ocular Functions (약시 치료에 의한 시감각 개선이 안기능 향상에 미치는 효과)

  • Kim, Jae-Do
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.4
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    • pp.551-555
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    • 2014
  • Purpose: This study is to investigate if the improvement of visual sensory (VS) by amblyopia treatment affects the ocular functions in refractive errors, accommodative errors and phoria at distance and near. Methods: 10 subjects (17 eyes, mean age of $10.7{\pm}2.9$ years) who treated amblyopia completely, were participated for this study. Refractive errors, accommodative errors, and distance and near phoria were compared between before and after treatments of amblyopia. Refractive errors and accommodative errors at 40 cm were measured using openfield auto-refractor (NVision-5001, Shin Nippon, Japan) and using monocular estimated method (MEM) respectively. Phoria was determined at 3 m for distance and at 40 cm for near using Howell phoria card, cover test or Maddox rod. Results: Mean corrected visual acuity (CVA) significantly increased from $0.46{\pm}0.11$ (decimal notation) for before amblyopia treatment to a level of $1.03{\pm}0.13$ for after amblyopia treatment (p < 0.001). For spherical refractive error, hyperopia significantly decreased from $+2.29{\pm}0.86D$ to a level of $+1.1{\pm}2.38D$ (p < 0.05) but astigmatism did not significantly change; $-1.80{\pm}1.41D$ for before treatment and $-1.65{\pm}1.30D$D for after treatment (p > 0.05). Accommodative error significantly decreased from accommodative lag of $+1.1{\pm}0.75D$ to a level of $+0.5{\pm}0.59D$ (accommodative lag) (p < 0.05). Distance phoria significantly changed from eso $2.9{\pm}6.17PD$ (prism diopters) to a level of eso $0.2{\pm}3.49PD$ (p < 0.05), and near phoria also significantly changed from eso $0.4{\pm}2.32PD$ to level of exo $2{\pm}4.9PD$ (p < 0.05). There was a high correlation (r = 0.88, p < 0.001) between improvement of visual acuity and decrease of accommodative lag. Conclusions: Hyperopic refractive error decreased with improvement of CVA or VS by amblyopia treatment. And the improvement of VS by amblyopia treatment also improved accommodative error, and changed phoria coupled with accommodation.

Distribution Model of the Wintering Red-crowned Crane and White-naped Crane in Cheorwon, Korea (철원지역에서 월동하는 두루미와 재두루미의 서식밀도모델)

  • Yoo, Seung-Hwa;Lee, Ki-Sup;Kim, Hwa-Jung;Hur, Wee-Haeng;Kim, Jin-Han;Park, Chong-Hwa
    • Korean Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.282-291
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    • 2014
  • This study was conducted to make distribution model of the Red-crowned Crane and the White-naped Crane according to the anthropogenic and natural factors affecting distribution of crane in Cheorwon, Korea. It was investigated that the impact power and its range of the indirect anthropogenic influence to feeding flock density in cranes from the road, residential area, military facilities, civilian control zone (CCZ), greenhouse and natural influence such as roosting site and available feeding area. Available feeding area is the most important factor for the crane's feeding site selection. The feeding flock density of the cranes near the residential area was lower than that of area far from the area, and tended to increase within 2.5 km distance. The increasing tendencies of feeding flock density from military facilities and high traffic volume road were similar, but the density in military facilities increased within 800 m, and the density from high traffic volume road increased within 2 km. These results suggested that residential area, military facilities and the road with high traffic volume had significant effect on foraging densities to the certain range. As the distance from the road with low traffic volume and roosting site increased, feeding flock density tended to decrease. The density of Red-crowned crane and White-naped crane inside the CCZ were respectively higher than those of outside the CCZ, especially for the Red-crowned crane. As a result, density of Red crowned cranes inside the CCZ was 5.2 times higher than that of outside, while that of white-naped cranes was 2.2 times bigger. If the density of greenhouse is lower than $40km^{-2}$, crane's feeding flock density in the low greenhouses density area was higher than that of high greenhouses density area. However, there was no difference in the feeding flock density if the density of the green houses is higher than $40km^{-2}$. The model for the Red-crowned Crane was related with available feeding area, distance from residential area, civilian control zone and distance from high traffic road. The model of the White-naped Crane was related with available feeding area, distance from roosting site and distance from lake. Finally, the estimated feeding flock density of cranes significantly correlated with density model according to the natural and anthropogenic factors.

Development of Landscape Urbanism in Practice (랜드스케이프 어바니즘의 실천적 전개 양상)

  • Kim, Youngmin;Jeong, Wookju
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.1
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    • pp.1-17
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    • 2014
  • The Practice of Landscape Urbanism has been criticized on two aspects; Landscape Urbanism does not yet provide differentiated forms of planning and design neither able to fill the gap between theory and practice. In response to these criticisms, Landscape Urbanists have tried to provide additional cases that can exemplify achievements of Landscape Urbanism in practice. There has been another type of effort to suggest distinct planning and design strategies of Landscape Urbanism from theoretical texts. However, these approaches overlooked the fact that professional practice actually gave huge influence on the theoretical framework of Landscape Urbanism. Based on this observation, the study examined the development process of Landscape Urbanism by verifying the correlation between its practice and theory. Through an extensive literature review, the study suggested horizontality, infrastructure, process, ecology, media, hybrid, site, and scale as eight major concepts of Landscape Urbanism. Afterwards, the study classified 51 projects cited in major essays and articles of Landscape Urbanism into four categories: Archetypal projects, precedent projects, exemplary projects, and progressive projects. The correlation between strategies of the selected projects and main theoretical concepts was analyzed. The study found out that the early stage of the theory was focused on defining and explaining the new design and planning approaches of contemporary design projects related with landscape. However, these days, Landscape Urbanism became a more productive in providing diverse types of practice sharing the direction and vision proposed by the theory. Various projects influenced in constructing theoretical structure of Landscape Urbanism as well as proved that the suggestions of Landscape Urbanism could be effective to reorganize contemporary cites in the form of design and planning strategies. The observation of this study can contribute to provide proper answers to the criticism on practice of Landscape Urbanism and be helpful in understanding the limits and unrealized potentials of Landscape Urbanism as a practical theory.

A Study on Hydromorphology and Vegetation Features Depending on Typology of Natural Streams in Korea (국내 자연하천의 유형별 물리적 구조 및 식생 특성 연구)

  • Kim, Hyea-Ju;Shin, Beom-Kyun;Kim, Won
    • Korean Journal of Environment and Ecology
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    • v.28 no.2
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    • pp.215-234
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    • 2014
  • The purpose of this study is to identify the type and characteristics of the domestic natural streams in order to establish a basis for stream restoration and evaluation. To this end, 95 domestic natural stream areas, which have various natural environments, were selected except for the province of island and then the characteristics of natural environment, hydromorpholoy, plant and vegetation were investigated and analyzed in each stream area. As a result, 95 stream areas were classified into total 24 types according to 3 criteria such as stream size (4 types), altitude (3 types), bed material (5 types). Depending on altitude class that is the environmental factor showing the highest correlation with each stream types, the emergence of vegetation and plant, 24 stream types were reclassified into 3 types such as lowland (altitude less than 200m), mountain (altitude from 200m to 500m), highland (altitude more than 500m), and hydromorpholoy, plant and vegetation characteristics of each stream type were compared. First, when compared to the mountain and highland streams, the typical features of lowland streams were as follows: Stream size was large but bed material size was small and there were many valley forms where flood plane were developed well. In addition, the more large stream size was, the more cross-section width variability, bars and sinuosity were in good conditions. In lowland stream, representative vegetation community was Salix koreensis community. On the other hand, when compared to the lowland streams, the typical features of mountain and highland streams were as follows: Stream size was small but bed material was coarse-grained and its size was large. Mountain and highland streams valley form where flood plane was not developed well was narrow, and sinuosity and bars development were weak. Representative vegetation communities of mountain streams were Quercus serrata -, Quercus variabilis -, Styrax japonica community and representative vegetation communities of highland streams were Pinus densiflora -, Quercus mongolica -, Fraxinus rhynchophylla community.

A Quick-and-dirty Method for Detection of Ground Moving Targets in Single-Channel SAR Single-Look Complex (SLC) Images by Differentiation (미분을 이용한 단일채널 SAR SLC 영상 내 지상 이동물체의 탐지방법)

  • Won, Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.30 no.2
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    • pp.185-205
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    • 2014
  • SAR ground moving target indicator (GMTI) has long been an important issue for SAR advanced applications. As spatial resolution of space-borne SAR system has been significantly improved recently, the GMTI becomes a very useful tool. Various GMTI techniques have been developed particularly using multi-channel SAR systems. It is, however, still problematic to detect ground moving targets within single channel SAR images while it is not practical to access high resolution multi-channel space-borne SAR systems. Once a ground moving target is detected, it is possible to retrieve twodimensional velocities of the target from single channel space-borne SAR with an accuracy of about 5 % if moving faster than 3 m/s. This paper presents a quick-and-dirty method for detecting ground moving targets from single channel SAR single-look complex (SLC) images by differentiation. Since the signal powers of derivatives present Doppler centroid and rate, it is very efficient and effective for detection of non-stationary targets. The derivatives correlate well with velocities retrieved by a precise method with a correlation coefficient $R^2$ of 0.62, which is well enough to detect the ground moving targets. While the approach is theoretically straightforward, it is necessary to remove the effects of residual Doppler rate before finalizing the ground moving target candidates. The confidence level of results largely depends on the efficiency and effectiveness of the residual Doppler rate removal method. Application results using TerraSAR-X and truck-mounted corner reflectors validated the efficiency of the method. While the derivatives of moving targets remain easily detectable, the signal energy of stationary corner reflectors was suppressed by about 18.5 dB. It results in an easy detection of ground targets moving faster than 8.8 km/h. The proposed method is applicable to any high resolution single channel SAR systems including KOMPSAT-5.

Dispersion Effect Based on Irradiation Dose and Position of QRD Microwave in Sealed Chamber (밀폐된 챔버의 QRD 마이크로파 조사용량과 위치에 따른 분산효과)

  • Kim, Jin Hyun;Han, Chung Su;Lee, Keun Woo;Lim, Kyoung Ho;Lee, Jae Hyun;Kim, Kyung Min;Ha, Yu Shin
    • Protected Horticulture and Plant Factory
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    • v.23 no.1
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    • pp.1-10
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    • 2014
  • This study analyzed the efficiency and uniformity by measuring the temperature change depending on the position in the chamber with the use of QRD (quadratic residue diffusor) microwave capable of inducing even sterilization by changing wavelength phase difference and enhancing the effect on low power. The results are summarized as follows: When irradiating 7 kW of QRD microwave, the highest efficiency was obtained at 35 cm height and in the center of the chamber. When irradiating 5 kW of QRD microwave, high efficiency was obtained on the sides of the chamber. When irradiating 3 kW of QRD microwave to Magnetrons 1, 2 and 3, the temperature uniformity according to the position of the bars was similar in the position of Bar 1 and 2. When irradiating 3 kW of QRD microwave to Magnetrons 3, 4 and 5, the temperature increased by approximately 10 to 20% in Bar 3. When irradiating 5, 7 and 9 kW of magnetron, the average temperature during the irradiation time increased in a similar form independently of the position of the bars. On the other hand, the efficiency of the chamber's proper internal volume was not necessarily proportional to the irradiation dose. When irradiating 3 kW of magnetron for 60 120 and 180 seconds, the temperature increased by approximately 5 to 10 at the edge of the chamber according to the irradiation position of magnetron. The temperature distribution for each position in the horizontal plane was relatively uniform, and the temperature had a tendency to slightly increase at the edge. When irradiating 5, 7 and 9 kW of magnetron, the temperature relatively evenly increased independently of the position of the bars. It was thought necessary to increase the irradiation dose by approximately 10 to 20% by considering the difference in temperature rise according to the position of magnetron.

Re-Analysis of Clark Model Based on Drainage Structure of Basin (배수구조를 기반으로 한 Clark 모형의 재해석)

  • Park, Sang Hyun;Kim, Joo Cheol;Jeong, Dong Kug;Jung, Kwan Sue
    • Journal of The Korean Society of Civil Engineers
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    • v.33 no.6
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    • pp.2255-2265
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    • 2013
  • This study presents the width function-based Clark model. To this end, rescaled width function with distinction between hillslope and channel velocity is used as time-area curve and then it is routed through linear storage within the framework of not finite difference scheme used in original Clark model but analytical expression of linear storage routing. There are three parameters focused in this study: storage coefficient, hillslope velocity and channel velocity. SCE-UA, one of the popular global optimization methods, is applied to estimate them. The shapes of resulting IUHs from this study are evaluated in terms of the three statistical moments of hydrologic response functions: mean, variance and the third moment about the center of IUH. The correlation coefficients to the three statistical moments simulated in this study against these of observed hydrographs were estimated at 0.995 for the mean, 0.993 for the variance and 0.983 for the third moment about the center of IUH. The shape of resulting IUHs from this study give rise to satisfactory simulation results in terms of the mean and variance. But the third moment about the center of IUH tend to be overestimated. Clark model proposed in this study is superior to the one only taking into account mean and variance of IUH with respect to skewness, peak discharge and peak time of runoff hydrograph. From this result it is confirmed that the method suggested in this study is useful tool to reflect the heterogeneity of drainage path and hydrodynamic parameters. The variation of statistical moments of IUH are mainly influenced by storage coefficient and in turn the effect of channel velocity is greater than the one of hillslope velocity. Therefore storage coefficient and channel velocity are the crucial factors in shaping the form of IUH and should be considered carefully to apply Clark model proposed in this study.