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Morphological Variations in Relation to Geographical Distribution of Pond Smelt, Hypomesus olidus Pallas (한국산 빙어의 지리적 형태변이에 대하여)

  • Ryu Bong Suk;LEE Kyung Ro
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.3
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    • pp.179-188
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    • 1981
  • The authors made an investigation concerning the geographical distribution and some major differentiations in morphological characteristics associated with the each habitat, of the pond smelt, Hypomesus olidus, which was introduced into Korea more than 50 years ago. Major characteristics utilized for the comparison study were upper jaw (maxillary), number of fin rays, scale structure, vertebral count, number of pyloric caeca, number of gill rakers, and the relative measurements of these and other internal characters. 1. The main areas of natural distribution are Paro Lake, Soyang Lake, Han River, Euirim Lake, and Ogjeong Lake (or Unam Lake) and the tributaries of these waters. 2. Morphological variations varied when the mean values of measurements from each area were compared with the standard measurement value by mosaic comparison, and in some instances a significant variation was found. 3. The most significant variations were found in the number of fin rays of pectoral and anal fins; the lengths from the tip of snout to the origin of pectoral fin, from snout to ventral fin, and from snout to anal fin, relative to standard body length; eye depth relative to head length; upper jaw: the number of pyloric caeca and the scale structure. Variations, on the other hand, by each habitat were not clear in the numbers of ventral and dorsal fin rays, gill rakers, vertebrae and lateral line scale : and the depth of caudal peduncle and distance from the tip of snout to the origin of dorsal fin relative to standard body length. 4. The scales of pond smelt showed some differences in the shape of scales, the shape and position of the focus and the number of ridges according to the scale positions on the body. No radii were present. The relations between longitudinal and transverse diameters of the scale suggest that the pond smelts of Soyang Lake and Un-am Lake are closely related, and those of Han River and Euirim Lake are also closely related. 5. The geographical variations in morphology of the pond smelt seem to have resulted from the variations in turbidity, water temperature, salinity (rather conductivity) and currents. 6. From the results obtained, it may be concluded that such factors as supramaxillary, relation between scale length and its breadth, number of caudal vertebrae and eye depth relative to head length may be used as the key characters for the classification of geographical varieties of Pond smelt.

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The Utilization Pattern of a Rural Health Subcenter among Suburban Farmhouse Members (일 도시근교 농가구원의 보건지소 이용양상)

  • Sohn, Seok-Joon;Kwon, Sun-Seok;Kim, Sang-Won;Byun, Ju-Nam;Nam, Hae-Sung;Son, Myung-Ho
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.65-77
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    • 1999
  • In order to estimate the utilization pattern of a rural health subcenter, and to identify the recognition for it among the farmhouse members in a suburban area, a questionnaire survey was carried out for objects of 696 population. The results observed were as follows: The annual utilization rate of rural health subcenter for a basic health service unit was 25.0 per 100 persons, and annual mean visiting times was 0.22 times. And the most frequent disease by annual health subcenter utilization illness was musculoskeletal disease(30.6%), and the next was respiratory disease(14.1%), gastrointestinal disease(13.9%) by order. Favorite reason for community health subcenter utilization were near distance from living place(49.6%), lower disease severity(18.9%) and lower medical cost(18.1%) by order. But disfavoring reasons for it were absence of specialist(20.2%), non effective treatment(19.2%) and insufficient equipment(14.7%) by order. And insufficient items about community health subcenter utilization were restriction of treatment limit(40.7%), lower reliance(22.5%) and difficulty in traffic(13.4%) by order. The results of logistic regression analysis suggested that statistically significant factors in health subcenter utilization was educational level. The desirable works for the health subcenter in a suburban area were disease control of elderly and disease preventing service. These results suggested that to increase the utilization of rural health subcenter in a suburban area and to promote the accessibility of rural residents to primary health care, there must be considered public relation about health subcenter, improvement of medical quality and change of priority about health subcenter's works.

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Grain-Size Trend Analysis for Identifying Net Sediment Transport Pathways: Potentials and Limitations (퇴적물 이동경로 식별을 위한 입도경향 분석법의 가능성과 한계)

  • Kim, Sung-Hwan;Rhew, Ho-Sahng;Yu, Keun-Bae
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.469-487
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    • 2007
  • Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.

Possible Effect of Western North Pacific Monsoon on Tropical Cyclone Activity around East China Sea (북서태평양 몬순이 동중국해 주변의 태풍활동에 미치는 영향)

  • Choi, Jae-Won;Cha, Yumi;Kim, Jeoung-Yun
    • Journal of the Korean earth science society
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    • v.38 no.3
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    • pp.194-208
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    • 2017
  • This study analyzed the correlation between tropical cyclone (TC) frequency and the western North Pacific monsoon index (WNPMI), which have both been influential in East China Sea during the summer season over the past 37 years (1977-2013). A high positive correlation was found between these two variables, but it did not change even if El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) years were excluded. To determine the cause of this positive correlation, the highest (positive WNPMI phase) and lowest WNPMIs (negative WNPMI phase) during an eleven-year period were selected to analyze the mean difference between them, excluding ENSO years. In the positive WNPMI phase, TCs were mainly generated in the eastern seas of the tropical and subtropical western North Pacific, passing through the East China Sea and moving northward toward Korea and Japan. In the negative phase, TCs were mainly generated in the western seas of the tropical and subtropical western North Pacific, passing through the South China Sea and moving westward toward China's southern regions. Therefore, TC intensity in the positive phase was stronger due to the acquisition of sufficient energy from the sea while moving a long distance up to East Asia's mid-latitude. Additionally, TCs occurred more in the positive phase. Regarding the difference in 850 hPa and 500 hPa stream flows between the two phases, anomalous cyclones were strengthened in the tropical and subtropical western North Pacific, whereas anomalous anticyclones were strengthened in East Asia's mid-latitude regions. Due to these two anomalous pressure systems, anomalous southeasterlies developed in East China Sea, which played a role in the anomalous steering flows that moved TCs into this region. Furthermore, due to the anomalous cyclones that developed in the tropical and subtropical western North Pacific, more TCs could be generated in the positive phase.

A Study of Clinical Investigations of Pulmonary Tuberculoma (폐 결핵종의 치료에 따르는 임상경과에 관한 연구)

  • Song, Suk Ho;Hahn, Hye Sook;Kyung, Sun Young;Hwang, Jun Kyu;An, Chang Hyeok;Lim, Young Hee;Park, Gye Young;Park, Jeong Woong;Jeong, Seong Hwan
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.4
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    • pp.330-337
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    • 2002
  • Background : A pulmonary tuberculoma is one of the most common causes of a solitary pulmonary lesion. Treating a tuberculoma is still controversial and there are few reports on antituberculosis chemotherapy. In this study, the clinical findings and changes in the size of tuberculomas on a radiograph after completing antituberculosis chemotherapy was investigated. Methods : The medical records, an chest radiographs of 18 pulmonary tuberculoma patients who were admitted to the Gachon medical school, Ghil medical center between April 1998 and August 2001, were reviewed. The symptomatic changes were recorded and the size of the tuberculomas following treatment were compared. To compare the size, the long distance of each tuberculoma on the chest radiographs were measured and the additional radiological findings of calcification, satellite nodules and cavities were investigated. Results : Fifteen patients were men and 3 were women. The median age was 46 (24-74). Among these 18 patients, 14 patients had clinical symptoms. The other 4 patients were diagnosed incidentally as during a routine chest radiograph. The mean size of the tuberculomas on the initial plain chest film was $4.3{\pm}2.3cm$(range : 1.7-10 cm) and after 6 months treatment, it had decreased to $1.68{\pm}2.00cm$(range : 1.5-6.5 cm) (P<0.05). At least 6 months of antituberculosis chemotherapy resulted in the findings of a tuberculoma with a disappearance in 9, a decreased size in 4, and no change in 5 on the chest radiograph. Calcifications were found in 3 patients on the initial chest film and the chest CT and all calcified tuberculomas had disappeared after treatment. Conclusion : Although a pulmonary tuberculoma can remain as an inactive lesion for a long time, if it is confirmed by pathological or bacteriological methods, antituberculosis chemotherapy will be beneficial despite the presence of calcification.

Correlation of Near Stereoacuity and Phoria, and Refractive Error (근거리 입체시와 사위 및 굴절이상의 상관관계)

  • Shim, Hyun-Suk;Kim, Sang-Hyun;Kim, Young-Cheong
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.1
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    • pp.67-73
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    • 2015
  • Purpose: This study was investigated the relationship between the male and female of near stereoacuity and phoria, and was examined the correlations between near stereoacuity and phoria and refractive error. Methods: Adult 83 (male 36, female 47, mean age $21.09{\pm}1.74$(19~29) years old) target was examined after full correction of refractive error. Near stereoacuity was measured by using Titmus-fly Stereotest(Stereo Optical Co., Inc., Chicago, IL, USA), and RANDOT Stereotest (Stereo Optical Co., Inc., Chicago, IL, USA), phoria was measured by using modified torrington method, at distance 40 cm. Results: In near stereoacuity, male was better good than female, and there was no difference between male and female (p>0.05). In near phoria, female was more higher than male, and there was a significant difference between male and female (p<0.05). Near stereoacuity by Titmus-fly test and Randot test result respectively was $262.17{\pm}562.43$ sec (second of arc) $243.08{\pm}68.04$ sec in esophoria, $148.42{\pm}269.54$ sec, $107.40{\pm}263.74$ sec in orthophoria, $113.94{\pm}152.46$ sec, $79.70{\pm}136.83$ sec in exophoria, there was a no difference between three phoria groups (p>0.05), and was a high correlation between phoria and near stereoacity(r=0.68). In addition, near stereoacuity in the refractive error respectively was $80.00{\pm}571.43$ sec, $68.75{\pm}36.82$ sec in myopia, $133.57{\pm}224.15$ sec, $93.14{\pm}214.95$ sec in hyperopia, $511.20{\pm}855.00$ sec, $511.4{\pm}855.60$ sec, there was a significant difference between three phoria groups (p<0.05). when was classfiied near stersoacuity into degree of refractive error, near stersoacuity was best in emmetropia, and was reduced when refractive error was highest in high degree myopia, and hyperopia. Conclusions: Titmus-fly Stereotest and RANDOT Stereotest result, near stereoacuity of adults, when esophoria and high degree refractive error, was reduced, there was a relationship between near stereoacuity with phoria, and refractive error. In this both stereotests if was bad when near stereoacuity can expect a phoria and refractive error.

Influence of Different Diagnostic Criteria on Frequency of Convergence Insufficiency (진단기준 차이가 폭주부족의 빈도에 미치는 영향)

  • Yu, Dong-Sik;Cho, Hyun Gug;Moon, Byeong-Yeon
    • Journal of Korean Ophthalmic Optics Society
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    • v.21 no.3
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    • pp.235-242
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    • 2016
  • Purpose: This study was to investigate whether the application of different diagnostic criteria affected the frequency of convergence insufficiency (CI). Methods: Eighty one subjects with mean age of 22.54 years (20 to 27 years) were evaluated. Binocularity tests after refraction were performed as the following tests: near point of convergence (NPC) with an accommodative target, phoria using von Graefe method, positive fusional vergence (PFV) with a phoropter. Subjects with CI were diagnosed when exophoria (exo) was greater at near than at distance ($exo{\geq}4{\Delta}$, or >$6{\Delta}$), fusional vergence was $PFV{\leq}11{\Delta}$ for blur, $PFV{\leq}15{\Delta}$ for break, Sheard's or Percival's criterion, and NPC was $NPC{\geq}6cm$, ${\geq}7.5cm$ or >10 cm. Results: Frequency of CI with one diagnostic criterion was ranged from 6.2% to 77.8%, and was overestimated or underestimated according to criteria. It was reduced to the range of 6.2% to 43.2% with diagnostic criteria more than two, especially to the range of 24.7% to 28.4% with lower variability in diagnostic criteria including phoria and Sheard's criterion. There were high relationship between total score of signs and phoria score (r = 0.772, p<0.001), and measured phoria and Sheard's criterion (r = -0.654, p<0.001), but NPC had a high variability and a weak or no significant relationship with other diagnostic criteria. Results suggested $exo{\geq}4{\Delta}$, Sheard's criterion and $NPC{\geq}7.5cm$ for diagnostic criteria of signs and sequence for CI. Conclusions: Frequency of CI is likely to be over- and underestimated with diagnostic criteria. Cutoff values and procedures for phoria, Sheard's criterion and NPC as clinical signs should be suggested definitely in diagnosis associated with CI.

Comparison of Center Error or X-ray Field and Light Field Size of Diagnostic Digital X-ray Unit according to the Hospital Grade (병원 등급에 따른 X선조사야와 광조사야 간의 면적 및 중심점 오차 비교)

  • Lee, Won-Jeong;Song, Gyu-Ri;Shin, Hyun-yi
    • Journal of the Korean Society of Radiology
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    • v.14 no.3
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    • pp.245-252
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    • 2020
  • The purpose of this study was intended to recognize the importance of quality control (QC) in order to reduce exposure and improve image quality by comparing the center-point (CP) of according to hospital grade and the difference between X-ray field (XF) and light field (LF) in diagnostic digital X-ray devices. XF and LF size, CP were measured in 12 digital X-ray devices at 10 hospitals located in 00 metropolitan cities. Phantom was made in different width respectively, using 0.8 mm wire after attaching to the standardized graph paper on transparent plastic plate and marked as cross wire in the center of the phantom. After placing the phantom on the table of the digital X-ray device, the images were obtained by shooting it vertically each field of survey. All images were acquired under the same conditions of exposure at distance of 100cm between the focus-detector. XF and LF size, CP error were measured using the picture archiving communication system. data were expressed as mean with standard error and then analyzed using SPSS ver. 22.0. The difference in field between the XF and LF size was the smallest in clinic, followed by university hospitals, hospitals and general hospitals. Based on the university hospitals with the least CP error, there was a statistically significant difference in CP error between university hospitals and clinics (p=0.024). Group less than 36-month after QC had fewer statistical errors than 36-month group (0.26 vs. 0.88, p=0.036). The difference between the XF and LF size was the lowest in clinic and CP error was the lowest in university hospital. Moreover, hospitals with short period of time after QC have fewer CP error and it means that introduction of timely QC according to the QC items is essential.

The Evaluation of External Radiation Exposure dose rate for Radium-223 Dichloride (Radium-223 Dichloride의 외부 방사선량의 평가)

  • Cho, Seong Wook;Yoon, Seok Hwan;Seung, Jong Min;Kim, Tae Yub;Im, Jeong Jin;Kim, Jin Eui
    • The Korean Journal of Nuclear Medicine Technology
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    • v.20 no.1
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    • pp.28-31
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    • 2016
  • Purpose $^{223}Ra-Dichloride$ is used for the medicine of castration-resistant prostate cancer (CRPC) and which emits ${\alpha}-ray$ of 28 Mev that is used for therapy. However $^{223}Ra-Dichloride$ emits ${\beta}-ray$ of 3.6% and ${\gamma}-ray$ of 1.1%(80,156,270 keV) aside from ${\alpha}-ray$ in decay. Therefore we would like to evaluate external radiation expose dose rate of ${\gamma}-ray$ of $^{223}Ra-Dichloride$. Materials and Methods We calculated external radiation expose dose rate using ${\gamma}-constant$ of $^{223}Ra-Dichloride$, $^{99m}Tc$ based on Health physics(2012). $^{223}Ra-Dichloride$ of 3.5 MBq and $^{99m}Tc-MDP$ of 740 MBq were applied. external radiation expose dose rate 15 times from 1m by survey meter. Results ${\gamma}-contant$ of $^{223}Ra$, $^{99m}Tc-MDP$ from 1m distance based on Health physics(2012) is 0.0469, 0.0215. calculated value of external radiation expose dose rate was $16{\mu}Sy$, $34{\mu}Sy$ which activity is $^{223}Ra-Dichloride$ of 3.5 MBq and $^{99m}Tc-MDP$ of 740 MBq from 1 m and measured mean value of 1 m was $0.7{\mu}Sy/h$, $18{\mu}Sy/h$. Conclusion ${\gamma}-constant$ of $^{223}Ra$ is higher than $^{99m}Tc$ based on Health physics(2012). however calculated maximum external radiation expose dose rate of $^{223}Ra-Dichloride$ is lower than $^{99m}Tc$ due to actually used quantity of activity of $^{223}Ra-Dichloride$ is small. measured value of $^{223}Ra-Dichloride$ is also lower than $^{99m}Tc-MDP$. Therefore external radiation expose dose rate of ${\gamma}-ray$ of $^{223}Ra-Dichloride$ is very low.

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Rietveld Structure Refinement of Biotite Using Neutron Powder Diffraction (중성자분말회절법을 이용한 흑운모의 Rietveld Structure Refinement)

  • 전철민;김신애;문희수
    • Economic and Environmental Geology
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    • v.34 no.1
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    • pp.1-12
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    • 2001
  • The crystal structure of biotite-1M from Bancroft, Ontario, was determined by Rietveld refinement method using high-resolution neutron powder diffraction data at -26.3$^{\circ}C$, 2$0^{\circ}C$, 30$0^{\circ}C$, $600^{\circ}C$, 90$0^{\circ}C$. The crystal structure has been refined to a R sub(B) of 5.06%-11.9% and S (Goodness of fitness) of 2.97-3.94. The expansion rate of a, b, c unit cell dimensions with elevated temperature linearly increase to $600^{\circ}C$. The expansivity of the c dimension is $1.61{\times}10^{40}C^{-1}$, while $2.73{\times}10^{50}C^{-1}$ and $5.71{\times}10^{-50}C^{-1}$ for the a and b dimensions, respectively. Thus, the volume increase of the unit cell is dominated by expansion of the c axis as increasing temperature. In contrast to the trend, the expansivity of the dimensions is decreased at 90$0^{\circ}C$. It may be attributed to a change in cation size caused by dehydroxylation-oxidation of $Fe^{2+}$ to $Fe^{3+}$ in vacuum condition at such high temperature. The position of H-proton was determined by the refinement of diffraction pattern at low temperature (-2.63$^{\circ}C$). The position is 0.9103${\AA}$ from the O sub(4) location and located at atomic coordinates (x/a=0.138, y/b=0.5, z/c=0.305) with the OH vector almost normal to plane (001). According to the increase of the temperature, $\alpha$* (tetrahedral rotation angle), $t_{oct}$ (octahedral sheet thickness), mean distance increase except 90$0^{\circ}C$ data. But the trend is less clearly relative to unit cell dimension expansion because the expansion is dominant to the interlayer. Also, ${\Psi}$ (octahedral flattening angle) shows no trends as increasing temperature and it may be because the octahedron (M1, M2) is substituted by Mg and Fe.

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