• The Journal of Engineering Geology
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• v.7 no.1
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• pp.81-90
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• 1997

The Korean historical 1iteratures describe that great eaathquakes with destructive damages occurred mainly in Kyongju-Ulsan areas during the period of 1 to 8 century and 16 to 17 century. It seems that the Ulsan fault system shows a little curved ttend with N-S strike in the southern part and diverges into three directions from the mid-northern lart of the fault. The dominant trends of the lineaments are NNE-SSW, NE-SW and NS directions. Trench excavation in the mid-northern part of the Ulsan fault shows thrust facies cutting slope deposit containing a compacted laminar structure whose origin may due to severe cryogenic activities of the last cold period(ahout 25OOO B.P.). Detailed observation of the facies gives some evidences related to two earthquake episodes of thrust components along the Ulsan fault system. Fault outcrop and trench study suggest that Ulsan fault seems to he one of the active fault which has reworked several times even in the late Quaternary.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.304-310
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• 2007

Bacillus cereus 1-1 strain produced 2 mM of ALA in the aerobic dark condition without any inhibitor like levulinic acid. The optimum culture conditions for the ALA production were that preculture and main culture were continued for 18 hr in TCY medium, and 16 mM of organic acids like acetic acid were added at the late log phase when the pH was 6.8. And the addition of 0.3% glucose was effective at the beginning of the main culture. ALA production was continued for more than 8 hr by the addition of glutamic acid instead of acetic acid, and was inhibited by addition of $40\;{\mu}M$ gabaculine seriously. These results confirmed that B. cereus 1-1 strain produced ALA through C-5 pathway.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.613-629
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• 1996

River terraces of glacial and interglacial periods are most developed in the Ungcheon River, midwestern coastal region of south Korea. Among these terraces, interglacial river terraces correspond to the thalassostatic terraces of eastern coastal region of Korea. Thus the former shoreline altitudes of the coastal region around Ungcheon River can be estimated by using relative heights of these interglacial thalassostatic terraces of Ungcheon River The former shoreline altitudes estimated from interglacial thalassostatic terraces of Ungcheon River are 80m, 50${\sim}$60m, 40${\sim}$45m, 30m, 25m(?), 15${\sim}$20m, and 10m. These estimates are almost identical with those of Quaternary sea levels of eastern coastal region. Among the above estimates of Ungcheon River, the former shoreline altituded of 15~20m and 10m correspond to the ancient sea levels of $\pm$18m and $\pm$10m of eastern coastal region which were injudged as the last interglacial culmination period and late warmer period of the last interglacia(5e and 5a substages of oxygen isotope stage), respectively. Therefore there is a possibility that the rest of the above former shoreline altitudes of the coastal region aroune Jngcheon River also correspond to those of eastern coastal region. On the basis of the above possibility it can be proposed that the eastern and western coastal region of Korean Peninsula have undergone tectonic uplift of equall amount since the middle Quaternary Period.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.160-168
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• 2017

Tscherskia triton is widely distributed in Northern China, Korea, and the adjacent areas of Russia. Except its distribution, reproduction, and growth development related to life history, reproductive cycle and reproductive organs of T. triton are rarely studied in Korea. The purpose of this study was characterized the estrous cycle of T. triton captured in Jeju Island in order to provide information to a better information of captive breeding of the species when long-day (16L : 8D) and short-day (8L : 16D) photoperiod. Then, histological study of the ovaries and uterus with five females in each photoperiod was performed. The duration of the estrus cycle was 4~5 days and it showed regular cycle pattern. Results of the vaginal cytology examination showed four characteristic phase of the estrous cycle in long-day photoperiod (16L : 8D): proestrus, estrus, metestrus and diestrus. However, in short-day photoperiod, the diestrus phage of the estrus cycle was maintained from the $6^{th}$ to $12^{th}$ day. In the long-day photoperiod, females had many Graafian follicles and corpus luteums in large ovaries, and developed uterine glands in the thick endometrium. But they had some primary, secondary and tertiary follicles, and undeveloped uterine glands in the thin endometrium during short-day photoperiod. These results were identified difference of the estrus cycle and histological characteristics of reproductive tracts according to the photoperiod. These results are very important clues to the reproductive biology of T. triton, and it will be widely used as date for maintaining biodiversity.

• Journal of the Korean Geophysical Society
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• v.5 no.4
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• pp.271-281
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• 2002

Interpretation of high-resolution seismic profiles collected from the inner shetf of the Korea Strait reveals that the shelf sequence in this area consists of three sedimentary units (I, II, and III in a descending order) formed after the last glacial maximum. Lower two units (II and III) represent the transgressive systems tract formed during the Holocene transgression, Unit III above the sequence boundary is interpreted to be the transgressive estuarine deposit, whereas Unit ll above the ravinement surface forms a thin transgressive sand which consists of the sediment produced through shoreface erosion and winnowing during the transgression. Unit I above the maximum flooding surface is the highstand systems tract consisting mainly of recent muds derived from the Nakdong River.

• Economic and Environmental Geology
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• v.51 no.3
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• pp.233-248
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• 2018

Strata of the Central sub-basin in the Gunsan Basin, offshore, western Korea were analyzed by using integrated stratigraphy approach. As a result, five distinct unconformity-bounded units are recognized in the basin: Sequence I (Cretaceous or older(?)), Sequence II (Late Cretaceous), Sequence III (late Late Cretaceous or younger(?)), Sequence IV (Early Miocene or older(?)), Sequence V (Middle Miocene). Since the late Late Jurassic, along the Tan-Lu fault system wrench faults were developed and caused a series of small-scale strike-slip extensional basins. The sinistral movement of wrench faults continued until the Late Cretaceous forming a large-scale pull-apart basin. However, in the Early Tertiary, the orogenic event, called the Himalayan Orogeny, caused basin to be modified. From Late Eocene to Early Miocene, tectonic inversion accompanied by NW strike folds occurred in the East China. Therefore, the late Eocene to Oligocene was the main period of severe tectonic modification of the basin and Oligocene formation is hiatus. The rate of tectonic movements in Gunsan Basin slowed considerably. In that case, thermal subsidence up to the present has maintained with marine transgressions, which enable this area to change into the land part of the present basin.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.87-94
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• 1975

By RH-531 treatments in Buheung, Suweon ＃ 165 and Suweon ＃ 18 of barley and Jangkwang, Namkwang and Suweon ＃ 85 of wheat, heading date and maturing date were delayed as the time of treatment delayed and as the concentration increased, field lodging in barley and lodging index in all cultivars were reduced, leaf growth after treatment showed erect elongation and darker green color, culm length and spike length and extrusion length were shortened, ripening ratio and yields were reduced, and protein contents in grain were increased. The effect of RH-531 treatment on each characteristics of each cultivars of barley and wheat was influenced more by treating time than concentration.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.55-61
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• 1979

Since rice high yielding practices with blast resistant varieties induced severe and earlier infestation of sheath blight recently, it is strongly suggested to spray at least 10 days earlier than the present recommendation and more than 2 sprays from early July to early August seems to be essential for the efficient control of sheath blight in the future. Among organo-arsenic fungicides, MAFe (Neo Asozin) is known as the most effective and economic as well as with the advantages of free phytotoxicity and safe residure on rice, and applications of the mixed formulation with other fungicide and insecticide is suitable for the one-hit control of rice diseases and insect pests in connection with cooperative mass control system. Present level of arsenic $(As_2O_3)$ residue in .ice is summarized as 0.2ppm to 0.65 ppm in highest average, and there are more possibilities of extensive MAFe fungicide uses for the efficient and economic control of this disease. During the past few years, the acreage of sheath blight control has been extended several times while the increase of the fungicides used for sheath blight showing about 10 times in quantity and mort than 15 times in amount, and also the fungicide cost estimated for the control is differ from 1 to 12 billion 1on by the use of MAFe or antibiotic fungicide in a year.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.109-122
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• 2011

The major Mo deposits in South Korea were formed during the Jurassic Daebo orogeny, the Late Cretaceous and the Tertiary post-orogenic igneous activities, and are characterized by a variety of genetic types such as pegmatite, greisen, skarn, porphyry and vein types. The Jangsu mine is a pegmatite-style deposit which is genetically related to the Jurassic ilmenite-series two-mica granite with the Mo mineralization age of $159.6{\pm}4.5$ Ma. The Geumseong mine occurs as a skarn/porphyry-style deposit associated with highly fractionated granite. Its age of Mo mineralization within aplitic cupola is about 96.5~l07.5 Ma. The Yeonil mine is a porphyry-style deposit, and the Geumeum mine is a veinlet-style deposit along the fracture zone with their mineralization ages of $58.4{\pm}1.6$ and $54.4{\pm}1.2$ Ma, respectively. The contrasts in the style of Mo mineralization in Korea reflect the different environment of the related magmatism. The Jurassic mineralization, being related to deep-seated granitoids, occurs as a pegmatite-style deposit, whereas the Cretaceous one, being related to subvolcanic granitoids, occurs as skarn/porphyry/vein-type ore deposits. The Tertiary Mo mineralization has a close relationship with the igneous activities associated with the Tertiary basin formation along the east coast, Korean peninsular.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.89-94
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• 1997

The present study was conducted to know the growth and yield of in response to the drought stress at the different soybean growth stage. Drought stress was given to the soybean plants on early vegetative growth at fourth-node stage(FNS), mid-growth at beginning pod stage(BPS) and late growth at beginning seed stage(BSS) for 30 days, which are high availability in soil water stress on climate condition of Korea. Dry weight was decreased severely by water stress at FNS, and BPS and BSS has no difference compared to control. Chlorophyll content of leaf severely decreased at the end of water stress of FNS and BPS, but was recovered at the harvest stage. Drought-stressed root distributed mainly near the soil surface and number and dry weight of root nodule were decreased severely by drought stress at BPS. Number of pod, seed weight and yield were decreased by drought stress and showed the highest yield loss at BPS.