• Title/Summary/Keyword: shallow depth

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Refractive Error Induced by Combined Phacotrabeculectomy (섬유주절제술과 백내장 병합수술 후 굴절력 오차의 분석)

  • Lee, Jun Seok;Lee, Chong Eun;Park, Ji Hae;Seo, Sam;Lee, Kyoo Won
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.12
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    • pp.1173-1180
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    • 2018
  • Purpose: We evaluated the postoperative accuracy of intraocular lens power prediction for patients undergoing phacotrabeculectomy and identified preoperative factors associated with refractive outcome in those with primary open-angle glaucoma (POAG). Methods: We retrospectively reviewed the medical records of 27 patients who underwent phacotrabeculectomy to treat POAG. We recorded all discrepancies between predicted and actual postoperative refractions. We compared the data to those of an age- and sex-matched control group that underwent uncomplicated cataract surgery during the same time period. Preoperative factors associated with the mean absolute error (MAE) were identified via multivariate regression analyses. Results: The mean refractive error of the 27 eyes that underwent phacotrabeculectomy was comparable to that of the 27 eyes treated via phacoemulsification (+0.02 vs. -0.01 D, p = 0.802). The phacotrabeculectomy group exhibited a significantly higher MAE (0.65 vs. 0.35 D, p = 0.035) and more postoperative astigmatism (-1.07 vs. -0.66 D, p = 0.020) than the phacoemulsification group. The preoperative anterior chamber depth (ACD) and the changes in the postoperative intraocular pressure (IOP) were significantly associated with a greater MAE after phacotrabeculectomy. Conclusions: POAG treatment via combined phacoemulsification/trabeculectomy was associated with greater error in terms of final refraction prediction, and more postoperative astigmatism. As both a shallow preoperative ACD and a greater postoperative change in IOP appear to increase the predictive error, these two factors should be considered when planning phacotrabeculectomy.

Petrogenesis of Mesozoic granites at Garorim Bay, South Korea: evidence for an exotic block within the southwestern Gyeonggi massif?

  • Kim, Ji In;Choi, Sung Hi;Yi, Keewook
    • Geosciences Journal
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    • v.23 no.1
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    • pp.1-20
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    • 2019
  • We present data from the Mesozoic Keumkang, Palbong, and Baekhwa granites in Garorim Bay, in the southwestern part of the Gyeonggi massif, South Korea. Using major and trace element concentrations, Sr-Nd-Pb isotopic compositions, and sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages, we aim to constrain the petrogenesis of the granites and explain their origin within a broader regional geological context. SHRIMP U-Pb zircon ages of $232.8{\pm}3.2$, $175.9{\pm}1.2$, and $176.8{\pm}9.8$ Ma were obtained from the Keumkang, Palbong and Baekhwa granites, respectively. The Late Triassic Keumkang granites belong to the shoshonite series and show an overall enrichment in large ion lithophile elements (LILE), a depletion in high field strength elements (HFSE) relative to primitive mantle, compared with neighboring elements in the primitive mantle-normalized incompatible trace element diagram with notable high Ba and Sr contents, and negligible Eu anomalies. The Keumkang granites are typified by highly radiogenic Sr and unradiogenic Nd and Pb isotopic compositions: $(^{87}Sr/^{86}Sr)_i=0.70931-0.70959$, $(^{143}Nd/^{144}Nd)_i=0.511472-0.511484$ [$({\varepsilon}_{Nd})_i=-17.0$ to -16.7], and $(^{206}Pb/^{204}Pb)=17.26-17.27$. The Middle Jurassic Palbong and Baekhwa granites belong to the medium- to high-K calc-alkaline series, and show LILE enrichment and HFSE depletion similar to the Keumkang granites, but exhibit significant negative anomalies in Ba, Sr, and Eu. Furthermore, they have elevated Y and Yb contents at any given $SiO_2$ content compared with other Jurassic granitoids from the Gyeonggi massif. The Palbong and Baekhwa granites have slightly less radiogenic Sr and more radiogenic Nd and Pb isotopic compositions [$(^{87}Sr/^{86}Sr)_i=0.70396-0.70908$, $(^{143}Nd/^{144}Nd)_i=0.511622-0.511660$, $({\varepsilon}_{Nd})_i=-15.4$ to -14.7, $(^{206}Pb/^{204}Pb)=17.56-17.76$] relative to the Keumkang granites. The Keumkang granites are considered to have formed in a post-collisional environment following the Permo-Triassic Songrim orogeny that records continent-continent collision between the North and South China blocks, and may have formed by fractional crystallization of metasomatized lithospheric mantle-derived mafic melts. The Palbong and Baekhwa granites may have been produced from a gabbroic assemblage at pressures of less than ~15 kbar, associated with subduction of the paleo-Pacific (Izanagi) plate at the Eurasian continental margin. Elevated ${\varepsilon}_{Nd}(t)$ values in the granitoids from the southwestern part of the Gyeonggi massif relative to those of the central and northern parts, together with the comparatively shallow depth of origin, imply the presence of an exotic block in the Korean lithosphere.

A New Potato Cultivar "Jayoung", with High Concentration of Anthocyanin (Anthocyanin 함량이 높은 감자 신품종 "자영")

  • Park, Young Eun;Cho, Ji Hong;Cho, Hyun Mook;Yi, Jung Yun;Seo, Hyo Won;Chung, Myoung Gun
    • Korean Journal of Breeding Science
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    • v.41 no.1
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    • pp.51-55
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    • 2009
  • Jayoung was bred within the potato breeding program of Highland Agriculture Research Center (HARC), National Institute of Crop Science. It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. Jayoung was evaluated as a clone number Daegwan 1-104 for the growth and tuber characteristics, yielding ability, and resistance to major potato diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as Jayoung and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. Jayoung has a oval shape, shallow eye depth, dark purple skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.3 MT/ha, and it showed the highest yield in spring cropping. Jayoung showed high resistance to both common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to late blight (Phytophthora infestans). The dry matter content of Jayoung was fairy high 20.3%, therefore it is suitable for both chip processing and table usage. Its anthocyanin content was the highest in autumn cropping as 43.7 mg/100 g fresh weight and its mean anthocyanin content was 4.7 times higher than that of Jasim.

Analysis of Lake Water Temperature and Seasonal Stratification in the Han River System from Time-Series of Landsat Images (Landsat 시계열 영상을 이용한 한강 수계 호수 수온과 계절적 성충 현상 분석)

  • Han, Hyang-Sun;Lee, Hoon-Yol
    • Korean Journal of Remote Sensing
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    • v.21 no.4
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    • pp.253-271
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    • 2005
  • We have analyzed surface water temperature and seasonal stratification of lakes in the Han river system using time-series Landsat images and in situ measurement data. Using NASA equation, at-satellite temperature is derived from 29 Landsat-5 TM and Landsat-7 ETM+ images obtained from 1994 to 2004, and was compared with in situ surface temperature on river-type dam lakes such as Paro, Chuncheon, Euiam, Chongpyong, Paldang, and with 10m-depth temperature on lake-type dam lake Soyang. Although the in situ temperature at the time of satellite data acquisition was interpolated from monthly measurements, the number of images with standard deviation of temperature difference (at-satellite temperature - in situ interpolated temperature) less than $2^{\circ}C$ was 24 on which a novel statistical atmospheric correction could be applied. The correlation coefficient at Lake Soyang was 0.915 (0.950 after correction) and 0.951-0.980 (0.979-0.997 after correction) at other lakes. This high correlation implies that there exist a mixed layer in the shallow river-like dam lakes due to physical mixing from continuous influx and efflux, and the daily and hourly temperature change is not fluctuating. At Lake Soyang, an anomalous temperature difference was observed from April to July where at-satellite temperature is $3-5^{\circ}C$ higher than in situ interpolated temperature. Located in the uppermost part of the Han river system and its influx is governed only by natural precipitation, Lake Soyang develops stratification during this time with rising sun elevation and no physical mixture from influx in this relatively dry season of the year.

Sea Surface Temperature Time Lag Due to the Extreme Heat Wave of August 2016 (2016년 8월 폭염에 따른 표층수온의 지연시간 고찰)

  • Kim, Ju-Yeon;Han, In-Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.677-683
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    • 2017
  • In this study, we examined responses to Sea Surface Temperature (SST) as the result of an intensive heat wave that took place in August 2016 and the cross correlation between SST and Air Temperature (AT) in August 2016. The data used included the SST of 8 ocean buoys, provided by the National Institute of Fisheries Science, and the AT of AWS near those 8 ocean buoys recorded every hour. To identify an appropriate data period, on FIR filter was applied. Two locations in the south sea were selected to be observed over similar a period, with a high correlation coefficient of about 0.8 and a time lag of about 50 hours between AT and SST. For the yellow sea, due to shallow waters and tidal currents, SST showed a rapid response caused by changes in AT. The east sea showed a negative correlation between AT and SST because of significant water depth and marine environment factors. By identifying the time lag between AT and SST, damage to aquatic organisms can be minimized, and we expect to develop a rapid response system for damage to the fishery industry caused by extreme heat waves.

The Study on the Spherulitic Rhyolites in the northern part of Juwang Mt., Cheongsong (청송 주왕산 북부 일대의 구과상 유문암에 대한 연구)

  • 오창환;김성원;황상구;손창환;김창숙;김형식
    • The Journal of the Petrological Society of Korea
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    • v.13 no.2
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    • pp.103-118
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    • 2004
  • In Cheongsong area, very rare spherulitic rhyolites both in Korea and foreign countries occur as dykes showing various types. The spherulites in them represent an undercooling caused by very fast cooling of the dykes in a shallow depth near to the surface and the variety of types were resulted from the difference of relative cooling rate. Cheongsong spherulitic rhyolites can be classified into five types; radiated simple spherulite, layered simple spherulite, layered multiple spherulite, radiated-layered multiple spherulite, radiating layered multiple spherulite. Radiated simple and radiating layered multiple spherulites formed by diffusion current caused by undercooling related to very fast cooling. On the other hand, layered multiple spherulites formed by relatively slow diffusion as a Liesegang ring during relatively slow cooling. If the cooling rate is between the two cases, layered simple spherulites formed. This interpretation indicates that Chrysanthemum, Dandelion, Dahlia and Sunflower types which are included in radiated simple or radiating layered multiple spherulites formed in the dykes with the fastest cooling rate in Cheongsong area while Peony, Rose and Innominate types classified as layered multiple spherulite formed in the dykes with the relatively slowest cooling rate. At the cooling rate between them, Apricot type spherulite formed. The K-Ar age-dating for Cheongsong spherulitic rhyolites indicate them to be formed between 48 and 50 Ma. The Cheongsong rhyolites are very valuable for research and preservation because of their rarity, beauty and diversity.

A New Potato Cultivar "Hongyoung", with Red Skin and Flesh Color, and High Concentrations of Anthocyanins (껍질과 속색이 붉고 Anthocyanin 함량이 높은 감자 "홍영")

  • Park, Young Eun;Cho, Ji Hong;Cho, Hyun Mook;Yi, Jung Yun;Seo, Hyo Won;Choung, Myoung Gun
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.502-506
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    • 2009
  • "Hongyoung" was bred within the potato breeding program of National Institute of Highland Agriculture (NIHA). It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. "Hongyoung" was evaluated as a clone number Daegwan 1-102 for the growth and tuber characteristics, yielding ability, and resistance to major diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as "Hongyoung" and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. "Hongyoung" has a round shape, shallow eye depth, red skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.4 MT/ha, and it showed the highest yield in spring cropping. "Hongyoung" showed high resistance to common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to both potato virus Y (PVY) and late blight (Phytophthora infestans). The dry matter content of "Hongyoung" was low to medium 17.7%, therefore it is suitable for table use. Its anthocyanin content was the highest in autumn cropping with 31.8 mg/100g fresh weight and it contained 3.6 times higher anthocyanin than the control, Jasim.

Review of Pre-grouting Methods for Shield TBM Tunneling in Difficult Grounds (특수지반에서 쉴드TBM 굴착 시 프리그라우팅 적용 사례 고찰)

  • Yoon, Youngmin;Jeong, Hoyoung;Jeon, Seokwon
    • Tunnel and Underground Space
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    • v.28 no.6
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    • pp.528-546
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    • 2018
  • Cases of TBM tunnelling have been consistently increasing worldwide. In many recent subsea and urban tunnelling projects, TBM excavation has been preferably considered due to its advantages over drill and blast tunnelling. Difficult ground conditions are highly probable to appear in subsea and urban tunnels because of the shallow working depth and alluvial characteristics. Under the difficult ground conditions, ground reinforcement measures should be considered including grouting, while it is of great importance to select the optimal grout material and injection method to cope with the ground condition. The benefits from TBM excavation, such as fast excavation, increased safety, and reduced environmental impact, can be achieved by applying appropriate ground reinforcement with the minimum overrun of cost and time. In this report, various grouting methods were reviewed so that they can be applied in difficult ground conditions. In addition, domestic and international cases of successful ground reinforcement for difficult grounds were introduced for future reference.

Acoustic Doppler Current Profiler Bottom Tracking Survey of Flow Structures around Geumo Archipelago in the Southern Waters of Korea (ADCP bottom tracking에 의한 금오열도 주변의 해수유동)

  • Choo, Hyo-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.5
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    • pp.589-600
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    • 2019
  • In order to investigate the flow structures around Geumo archipelago on Southern Waters of Korea, water movements were measured for 25 hours during spring tide in May and neap tide in September 2002 using ADCP (Acoustic Doppler Current Profiler) attached to a running boat. Dominant directions of ebb and flood current at spring tide are SE-NW, representing the average flow rate of approximately 40cm/s in the surface layer. However because of the topographical reason, the direction and speed of the flow in the narrow waterway sea area around the northwest of Gae Island were different. There was no notable baroclinic component of tidal flow at spring tide. This indicates that the sea area has been actively engaged in vertical mixing due to island wake or eddy due to narrow waterways, shallow water depth and rapid flow rate around archipelago. At neap tide, dominant directions of tidal flows are SSE-NNW and the average flow rate in the surface layer is about 85 percent of the spring tide. The duration and intensity of the flow direction are shorter and less dominant than the spring tide. It is expected that asymmetrical tidal mixing will occur due to vertical velocity shear and horizontal eddies. From daily mean tidal flows obtained from the ADCP observation, it was found that the northwest of Gae Island have flows in NW~NE, the west of Geumo Island have the average currents of up to 21 cm/s WSW~SSW and counterclockwise circulation or eddy currents are formed in the west of Sori Island.

Achievements and Tasks of Korea-Japan Geophysical Exploration through Burial mounds Exploration (고분 탐사를 통해 본 한·일 물리탐사의 성과와 과제)

  • Shin, Jong woo
    • Korean Journal of Heritage: History & Science
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    • v.48 no.4
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    • pp.74-93
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    • 2015
  • Geophysical survey of Korea was introduced in Nara National Research Institute of Cultural Heritage in 1995. At that time, it has been activated geophysical survey of architecture and civil engineering in Korea. But there was no exploration experts to be combined the archaeology. For this reason, National Research Institute of Cultural Heritage has introduced the physical exploration. Through the expert exchanges South Korea and Japan carried out joint exploration. And it has increased the reliability of the exploration method and exploration results. It is GPR the most method commonly in geophysical exploration. There are many usability before excavation because of good resolution. However, the shallow GPR penetration depth has limitations in large mounds. We were able to take advantage of the resistivity analysis program to study the underground structure to deep through the experts exchange. We was able to get a good result that overcomes the limitations of GPR exploration in a number of burial mounds including Naju bokamri by the resistivity analysis program. In particular, we confirmed the location of the burial main body by compares the results of exploration and excavation results. In the future we will perform a convergence research of exploration and archaeology through a variety of joint research. In addition we will have to build a new network of archaeological science.