• Title/Summary/Keyword: Total Variation

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Catch variation of a set net fishing ground in the coastal waters off Neungpo, Goeje Island (거제도 능포 정치망 어장의 어획물과 어획량 변동요인)

  • Cha, Byung-Yul
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.4
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    • pp.211-222
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    • 2009
  • The fisheries resources by a set net in the coastal waters off Neungpo, Goeje Island from 2003 to 2004 were studied to determine species composition and catch variation. The main fishing period by a set net were from April to December in 2003 and from May to December in 2004. A total weight of 48 species caught through the survey period was 540,688.0kg. Most of them were 44 species of fishes and a few were 4 species of cephalopods. Dominant species was Trachurus japonicus accounting to 57.5% in total catch. Sub-dominant species were Trichiurus lepturus(12.9%), Engraulis japonicus(10.6%), Scomber japonicus(6.9%), Clupea pallasii(4.5%), Todarodes pacificus(2.8%) and Parapristipoma trilineaturm(1.3%). The remnant species showed a low catch, indicating the catch had less than 1% in total, respectively. T. japonicus and T. lepturus were caught throughout the survey period, but C. pallasii, Gadus macrocephalus, Oncorhynchus keta in low temperature season and Thunnus obesus in high temperature season. The fishing ground temperature was 11.7-24.0${^{\circ}C}$ in range and the catch by a set net was higher in autumn than in spring and in summer with the variation of fishing ground temperature. The annual catch by a set net was much higher in 2004 than in 2003 due to high temperature(>17${^{\circ}C}$) and the recruitment of T. japonicus from offshore seas. Therefore we concluded that the catch of Neungpo fishing ground by a set net was highly related to the variation of T. japonicus catch with fishing ground temperature.

Analysis of Irradiation and Power per Each Seasons of Photovoltaic Systems (태양광 발전시스템의 계절별 일사량과 전력량 분석)

  • Kim, Seok-Gon;Hwang, Jun-Won;Lee, Ying;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2009.04a
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    • pp.43-45
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    • 2009
  • In case of favourable irradiation conditions, the ratio of irradiation to the total irradiation went up and then the irradiation increased in the area with high angle of inclination. The study showed that on a clear day with the irradiation of more than 80$[W/m^2]$, the pattern of alternating current power change in the fixed system was similar with that in the single-axis tracker. On the contrary, in case of unfavourable irradiation conditions, the ratio of diffuse irradiation to the total irradiation went up and then the horizontal irradiation increased. In the demo system, the fixed system, the single-axis tracker and the dual-axis tracker all had low generation power and similar generation pattern with each other. The study showed the generation power varied with the irradiation in the fixed system, while in the single-axis tracker and the dual-axis tracker, the amount of the generation Power variation was much more than the irradiation variation. The demo system was operated from 11:00 AM to 2:00 PM for generating power, during which time, 46[%] to 56[%] of the total generation power was produced. In this study, the generation power was increased by 147[%] in the fixed system, by 136[%] in the single-axis tracker, and by 164[%] in the dual-axis tracker, and the pattern of generation power was similar with the generation power variation in the situation where the irradiation increased by 140[%] in the spring with plenty of insolation. The alternating current power was more sensitive to variation of the irradiation than to that of the surface temperature of a module. The variation of the irradiation had a more positive effect on the generation power than the type of array.

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Contribution of Specific Foods to Absolute Intake and between-Person Variation of Nutrient Consumption in Korean Adults Living in Rural Area (24시간 회상법으로 조사한 한국 농촌성인의 섭취영양별 주요 급원식품 및 변이식품)

  • 이심열;백희영
    • Journal of Nutrition and Health
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    • v.33 no.8
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    • pp.882-889
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    • 2000
  • This study was conducted to examine contribution of specific foods to absolute intake and between-person variation in nutrients consumed by 2037 adults living in Korean rural area using one day 24-hour recall method. To measure contribution of food to absolute nutrient intake, all foods consumed were ranked by percentages calculated as the sum of the nutrient intake contributed by a given food divided by the total nutrient intake from al categories. To assess between-person variability in nutrient intake, stepwise multiple regression analysis was used with total nutrient intake from al foods as the dependent variable and the nutrient amount from each of all foods as independent variables. The kind and the number of foods necessary to account for the variation in nutrient intake among persons varied significantly depending on the nutrient. The nutrients contributing more than 80% of total intake with a few number of food items were ${\beta}$-carotene(ll), vitamin C(15) and vitamin A(16). Foods sometimes overlooked as important sources were found in some instances to be quantitatively important to population intake. Even though rice and Korean cabbage kimchi do not contain much nutrients in quantity, they made a major contribution to most nutrient intake of subjects because of large serving size and high frequency of intake. The food items and contributing order for between person variance was different from those of absolute intake. A large fraction of the variability of nutrient intake in this population was explained by a small number of foods. Fewer foods were required to explain a given proportion of the between-person variance in intake than to account for the same proportion of the popylation\`s total intake. These data may be useful in the development of dietary assessment instrument and in nutrition education. (Korean J Nutrition 33(8) : 882-889, 2000)

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Quantification and Varietal Variation of Free Sugars in Mulberry Fruits (뽕나무 계통별 오디의 유리당 조성 및 함량)

  • 김현복;김선림;문재유;장승종
    • Journal of Sericultural and Entomological Science
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    • v.45 no.2
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    • pp.80-84
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    • 2003
  • The component and content of free sugar in mulberry fruits were evaluated. In all accessions, fructose and glucose were identified as the major free sugar. The ratio of two components appeared in the same level. But CV (coefficient of variation. %) of fructose and glucose were 23.6%, 23.4%, respectively. It might suggest that varietal variation exists in sugar contents. The mean of total free sugars were 9.11${\pm}$2.14%. Among the tested 49 accessions, ‘Geunanosang’ showed the highest total free sugars in 14.67%, whereas ‘Cheongsipyung’ showed the lowest total free sugars in 5.57%. Also fruity characteristics as well as total free sugars to select the desirable mulberry varieties for the production of fruit were researched and analyzed. From that results, four suitable varieties such as ‘Hwansipchosaeng’, ‘Junggojo’, ‘ Kaery-angchosaengsipmunja’, and ‘Geunanosang’ were selected.

Habitat selectivity of fresh water fishes of two second-order tropical streams in Tigray, Northern Ethiopia

  • Tesfay, Solomon;Teferi, Mekonen;Tsegazeabe, Haileselasie Hadush
    • Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.73-83
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    • 2019
  • Background: Habitat selectivity and ecology of freshwater fishes were studied in two selected streams and their junction point which consist a total of 39 microhabitats. The aims of this study were to describe the habitat preference and its availability to fish assemblage, as well as ecology, habitat use, and habitat characteristics. Methods: We collected fish with backpack electrofishing three times during August 2013, December 2013, and March 2014. Using a variation partitioning approach of R software, we studied the relationship of fish abundances with stream type, habitat type, and abundance of key macroinvertebrate taxa. Results: A total of 6554 fishes representing four species belonging to the family Cyprinidae were caught. A higher total fish abundance was recorded from Gereb Tsedo (4870; 74.3%) than from Elala stream (1684; 25.7%). Taking both streams together, the overall total relative fish abundance was significantly higher in pools (53%) than in runs (35%) and in riffles (12%) at P < 0.05. Species-wise comparisons showed that 71%, 15%, 13%, and 1% of the pool fish community were occupied by Garra blanfordii, Garra ignestii, Garra dembecha, and Garra aethiopica, respectively. Stream type, habitat type, and key macroinvertebrate taxa each explained a significant proportion of the variation in fish abundance. Based on the variation partitioning approach, fish abundance was higher in Gereb Tsedo stream (P < 0.01). Moreover, fish abundance increased with pool habitat type (P < 0.01) and with availability of key macroinvertebrate taxa (P < 0.01). Conclusion: Fish abundance differed between stream types, among habitats and among key macroinvertebrate taxa availability. Among the factors, habitat type was the most important driving factor behind variation among fish abundances, and pool supports the highest fish abundance.

Anisotropic Total Variation Denoising Technique for Low-Dose Cone-Beam Computed Tomography Imaging

  • Lee, Ho;Yoon, Jeongmin;Lee, Eungman
    • Progress in Medical Physics
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    • v.29 no.4
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    • pp.150-156
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    • 2018
  • This study aims to develop an improved Feldkamp-Davis-Kress (FDK) reconstruction algorithm using anisotropic total variation (ATV) minimization to enhance the image quality of low-dose cone-beam computed tomography (CBCT). The algorithm first applies a filter that integrates the Shepp-Logan filter into a cosine window function on all projections for impulse noise removal. A total variation objective function with anisotropic penalty is then minimized to enhance the difference between the real structure and noise using the steepest gradient descent optimization with adaptive step sizes. The preserving parameter to adjust the separation between the noise-free and noisy areas is determined by calculating the cumulative distribution function of the gradient magnitude of the filtered image obtained by the application of the filtering operation on each projection. With these minimized ATV projections, voxel-driven backprojection is finally performed to generate the reconstructed images. The performance of the proposed algorithm was evaluated with the catphan503 phantom dataset acquired with the use of a low-dose protocol. Qualitative and quantitative analyses showed that the proposed ATV minimization provides enhanced CBCT reconstruction images compared with those generated by the conventional FDK algorithm, with a higher contrast-to-noise ratio (CNR), lower root-mean-square-error, and higher correlation. The proposed algorithm not only leads to a potential imaging dose reduction in repeated CBCT scans via lower mA levels, but also elicits high CNR values by removing noisy corrupted areas and by avoiding the heavy penalization of striking features.

Seasonal Variation of Total Bacterial Number and Environmental Factors in Daechung Reservoir (대청호에서 계절에 따른 세균 군집 및 환경요인의 변화)

  • Bing, Sun-Hye;Lee, Sang-Wook;Hwang, Soon-Jin;Oh, In-Hye
    • Korean Journal of Ecology and Environment
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    • v.35 no.2 s.98
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    • pp.71-78
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    • 2002
  • Seasonal change of total bacterial numbers were estimated in Daechung Reservoir from September, 1998 to August, 1999 and environmental factors which affects total bacterial numbers were estimated. Total bacterial numbers ranged between 1.2 and $19.0{\times}10^6\;cells/ml$ and averaged $6.9{\times}10^6\;cells/ml$. Bacterial numbers changed dynamically with season. The bacterial numbers were highest in July and showed peaks in April and July in sites studied except for the HOE (Hoenam site), In the HOE (Hoenam site), total bacterial numbers increased eve the period of March${\sim}$August. The correlation coefficient between bacterial number and chlorophyll a (<$200\;{\mu}m$) was r = 0.72(p< 0.05) at the MAN (man site). Total bacterial numbers in Daechung Reservoir was diversely changed by the seasonal variation of several environmental quality parameters.

Transistor Matching in 70 nm nMOS for RF applications (70 nm nMOS의 RF 적용을 위한 transistor matching)

  • Choi, Hyun-Sik;Hong, Seung-Ho;Jeong, Yoon-Ha
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.583-584
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    • 2006
  • This paper presents transistor matching in 70 nm nMOS. To adopt radio frequency(RF) applications, the RF performance, especially the current gain cutoff frequency($f_T$), is examined experimentally through a wafer. It is proved that the RF performance variation of 70 nm nMOS is dependent to the device geometry, the total width(W). The RF performance variation of 70 nm nMOS is inversely proportional to square root of total width(W). Also, decreasing of the number of fingers($N_f$) is helpful to decrease the variation of 70 nm nMOS.

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Development of A Computerized Risk Management System for International EPCS Projects

  • Yoo, Wi Sung;Kim, Woo-young;Sung, Yookyung
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.614-615
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    • 2015
  • In these days, global construction market is speedily increasing and domestic construction companies have a chance of new contracts. In the meantime, international projects have been increasingly forced to cope with potential risks, which seriously impacted achieving the targeted time and cost. In this study, we introduce a computerized risk management system for international EPCS projects, which is constructed on the needs of practitioners and decision makers as an aid to proactively control the potential risks and to monitor continuously their status and variation. The system is called the Project Risk Management System (PRiMS) is useful for furnishing project managers with warning signals as a project is progressing and helpful for producing the total risk score and tracking risk variation.

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A Study on the Variation in Meical Service Utilization of The Dead by Cerebrovascular Diseases Patients in Korea (뇌혈관질환 사망자 의료이용 변이의 분석)

  • Hong, Worl-Lan;Jung, Doo-Chae
    • Korea Journal of Hospital Management
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    • v.14 no.1
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    • pp.36-61
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    • 2009
  • This study focused on finding the variation of medical service utilization, paths of medical service utilization and medical payments of the patients died by cerebrovascular diseases. For this study, data of the one-year episodes of the health insurance subscribers died in 2004 were selected. The frequency of medical visits, the lengths of stays, the days of outpatient visits, the total period of medical services and the total medical payments were compared by the characteristics of the suppliers and utilizers. This study is useful in reviewing the equity of medical service utilization because it analyzed variance in utilization by episodes. In oder to collect accurate data of the patients died by cerebrovascular diseases in 2004 the 2004 reimbursement data of all medical institutions were matched to the data of funeral fee payment by the National Health Insurance Corporation from January 2004 to May 2005. The major results of the study are as follows. The variation of medical service utilization of cerebrovascular diseases was influenced by supplier factors suppliers, such as types and locations of medical institutions and user factors such as sex and age. It was suspected that the reimbursement by fee-for-service contributed to the variation quite a lot, but we could not compare the variation between the different reimbursement systems in Korea. On the basis of analyzing results this study suggests that the factors of suppliers and utilizers should be reviewed to reduce the under use and over use expressed by variations of medical service. The processes of care, effective communication and management system should be investigated for the equity of medical service utilization and also. alternative medical services would be recommended to reduce the high medical payment. Additionally to find other causes of variation further in depth study controling the severity of diseases, socio-economic status of the users and the system factors is required.

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