• Economic and Environmental Geology
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• v.35 no.2
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• pp.171-177
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• 2002

Two piston-core sediments, obtained from the southwestern margin of the Ulleung Basin in East Sea, are analyzed to investigate the stratigraphy and sedimentary environment of the Late Quaternary. The cores consist mainly of cuddy sediments with silty sands, lapilli tephra and ash layers. The chronostratigraphic correlation with known eruption ages reveals that the core sediments contain the stratigraphic document over the past 46.1 kyr and the sedimentation rates during the last glacial period were relatively higher (12.1-14.9 cm/kyr) than those in pelagic ocean. Several sedimentary facies, mainly affected by turbidity currents, are commonly present in the core interval accumulated during the oxygen-isotope stage 2. Many of horizontal voids, which are thought to have formed by gas expansion, are observed in fore 00GHP-07. The total organic carbon (TOC) contents of the core sediments are noticeably high (average 1 .8%). Particularly, these TOC valuers increased during Termination I, suggesting that dering this time interval the sedimentary environment of the study area was changed to more anoxic.

• Journal of the Korean association of regional geographers
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• v.22 no.3
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• pp.703-713
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• 2016

This study documents the altitude of paleo-shoreline and formation age of the $1^{st}$ marine terrace emerged around Heunghae-eup Pohang City (South Korea). As a result, the $1^{st}$ terrace representing 10 m of the paleo-shoreline was formed at MIS 5c around 100,000 BP and was influenced repetitive sedimentation of sea-wave till regression of MIS 5a. The result is recognized as a definite truth for the $1^{st}$ terrace in the eastern coast of the Korean peninsula based on synthetic reviews of previous studies and cross-validation of absolute age data. Furthermore, this study deduces a sea stand at MIS 5c from the geomorphological contrast method, but precise determination of paleo-shoreline of the $2^{nd}$ terrace should be required to estimate that of MIS 5c.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.117-122
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• 2003

This study is conducted to examine the woods that were excavated at Jangdo Island. The Jangdo site is located in a small island some 180 meters away from the main island of Wando, Jeollanam-do in southern Korea. This site is known as Cheong-Hea Jin fort for the marine King Jang Bogo during the early 9$^{th}$ century. Total of 101 specimens were collected in three groups； small-size piles, log fences (Mok-check) and logs from a well. The species of the group of piles consisted of Quercus spp. (43%), Pinus densiflora (29%), Pinus koraiensis (5%), Alnus japonica (3%), Fraxinus spp. (3%), Styrax obassia (3%), Juglans spp. (2%), Zelkova serrata (2%), Platycarya strobilacea (2%), Celtis spp. (2%), Torreya nucifera (2%), Quercus myrsinaefolia (2%), and Cinnamomum spp. (2%). The species of Mok-check and logs from the well were identified as all Pinus densiflora. The species composition indicated that the climate around A. D. 9th-10th century in southern Korea was similar to the present.. The wooden fences were also examined for tree-ring analysis. The ages of woods were 50∼60 years. We made two site chronologies. The chronologies indicated that southeastern and southwestern fences were repaired frequently. The results could not give the absolute dates due to lack of reference chronologies in this period.

• The Korean Journal of Quaternary Research
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• v.2 no.1
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• pp.51-85
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• 1988

The understanding of the faunal sequence and palaeoenvironment of East Asia since the Late Tertiary depends mainly on the knowledge of Chinese fauna and its environmental changes. The recent Chinese researches including geology, geomorphology, climats fluctuation and loess distribution of this area have provided that the rapid uplifting of Himalayas and Qinghai/Xizang Plateau since the Lower Pleistocene was a main selective factor for the process of environmental changes in this vast territory. Although different concepts of the Plio-Pleistocene boundary have been provided, its boundary can not exceed over 2 mya. Instead of the traditional zoogeographical dicthomy in China, faunal compositions of Pleistocene are divided into three faunal zones. The knowledge of macrofaunal evolution in China are useful to understand the palaeoecology of East Asia. Palaeoenvironment of Korea during the Pleistocene Period can be reconstructed by using the analogy of the current Chinese studies.

• The Korean Journal of Quaternary Research
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• v.25 no.2
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• pp.39-48
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• 2011

Phytolith analysis of sediments at the river mouth of valley bottom plains in Myosa-ri, Haman is performed. By the phytolith results, Phragmites and Oryza sativa are dominated in the lower horizon. An abundance of Paniceae and Andropogoneae indicates the active agricultural activities under wet conditions. Moreover, the results of archeological studies suggest the paddy fields in the Three States Age. The phytolith assemblages are dominated in the middle horizon and they gradually increase in the upper horizon. The rice cultivation layer is not proportional to total phytolith yield due to the dominance of Oryza sativa in the lower horizon. However, because the Oryza sativa are continuously observed over the entire sediments, it is suggested that there had been the agricultural activities for the entire periods.

• Current Photovoltaic Research
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• v.2 no.3
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• pp.88-94
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• 2014

The structural, optical and electrical properties of sputter-deposited CIGS films were directly influenced by the sputtering process parameters such as substrate temperature, working pressure, RF power and distance between target and substrate. CIGS thin films deposited by using a quaternary target revealed to be Se deficient due to Se low vapor pressure. This Se deficiency affected the overall stoichiometry of the films, causing the films to be Cu-rich. Current tends to pass through the Cu-Se channels which act as the shunting path increasing the film conductivity. The crystal structure of CIGS thin films depends on the substrate orientation due to the influence of surface morphology, grain size and stress of Mo substrate. The excess of Cu was removed from the CIGS films by KCN treatment, achieving a suitable Cu concentration (referred as Cu-poor) for the fabrication of solar cell. Due to high Cu concentrations on the CIGS film surface induced by Cu-Se phases after CIGS film deposition, KCN treatment proved to be necessary for the fabrication of high efficiency solar cells. Also during KCN treatment, dislocation density and lattice parameter decreased as excess Cu was removed, resulting in increase of bandgap and the decrease of conductivity of CIGS films. It was revealed that Cu-Se secondary phase could be removed by KCN wet etching of CIGS films, allowing the fabrication of high efficiency absorber layer.

• The Korean Journal of Quaternary Research
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• v.25 no.1
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• pp.31-39
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• 2011

Phytolith of soil in earthenware buried in the wooden chamber tombs at the archaeological site in Hwangseong-dong, Gyeongju along Hyeongsan River are analyzed. The study area has adjoined the seat of government during approximately thousand years in Shilla Dynasty and can be regarded as being closely related to the agricultural activities using the floodplains of Hyeongsan River. By the analytical results, Phragmites, Paniceae and Andropogoneae as well as Oryza sativa are found in the lower horizons, indicating the agricultural activities in the nearby areas. It is suggested for understanding the use of earthenware that the comparisons of buried soils in the site and soils in the earthenware and analysis on the macro plant fossils of soil in the earthenware are needed.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.27-41
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• 2017

In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.74-79
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• 2005

Recently, several attempts have been made to provide reasonable information on unusual severe weather phenomena such as tolerant heavy rains and very wild typhoons. Quantitative precipitation forecasts and probabilistic quantitative precipitation forecasts (QPFs and PQPFs, respectively) might be one of the most promising methodologies for early warning on the flesh floods because those diagnostic precipitation models require less computational resources than fine-mesh full-dynamics non-hydrostatic mesoscale model. The diagnostic rainfall model used in this study is the named QPM(Quantitative Precipitation Model), which calculates the rainfall by considering the effect of small-scale topography which is not treated in the mesoscale model. We examine the capability of probabilistic diagnostic rainfall model in terms of how well represented the observed several rainfall events and what is the most optimistic resolution of the mesoscale model in which diagnostic rainfall model is nested. Also, we examine the integration time to provide reasonable fine-mesh rainfall information. When we apply this QPM directly to 27 km mesh meso-scale model (called as M27-Q3), it takes about 15 min. while it takes about 87 min. to get the same resolution precipitation information with full dynamic downscaling method (called M27-9-3). The quality of precipitation forecast by M27-Q3 is quite comparable with the results of M27-9-3 with reasonable threshold value for precipitation. Based on a series of examination we may conclude that the proosed QPM has a capability to provide fine-mesh rainfall information in terms of time and accuracy compared to full dynamical fine-mesh meso-scale model.

• 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.