• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1981.05a
• /
• pp.39.3-40
• /
• 1981

Concerning the pathogenesis of acquired cholesteatoma in attic, there has been postulated theories by immigration from the Shrapnell's portion of the tympanic membrane, posterosuperior quardrant of the deep meatal skin and invagination of the margin of the central perforation. Otherwise, squamous metaplasia of the epithelium lining the middle ear cleft has been supported as a possible cause of cholesteatoma. Clinically, there has been known of the facts that cholesteatoma is formed in the attic but the pathogenesis concerning the acquired cholesteatoma is not still exactly reported. Recently, authors analyzed 170 cases of cholesteatomatous middle ear performed the operation to the middle ear cleft. On the operation finding, when the primary focus of the cholesteatoma was in the attic, we observed two types of perforation, marginal and central perforation in the Shrapnell's portion, and retraction to the Prussak's space, bony defect on the Rivinus notch. Among 36 cases of the cholesteatoma, the perforation of the Shrapnell's portion are 5 cases. Bony defect on the Rivinus notch and marginal perforation on the posterosuperior quadrant of the Shrapnell's portion are 21 cases. Among these cases, 3 cases are combined with central perforation of the Shrapnell's portion. Conclusively, the reasons that cholesteatoma is favorable site in the attic: 1) Excretion of the inflammatory discharge in the attic is difficult because of the distance of the E-tube. 2) The Shrapnell's portion has less collagen fiber than the pars tensa and it is thin because the elastic fibers are rich in it. It is easy to retract within the Prussak's space to the cases of keratinizing hyperplasia. 3) The epidermis attached at the Rivinus notch of the superior portion on the Shrapnell's portion is invaginated through the destructed bony wall of the Rivinus notch and the margin of the tympanic membrane in the response to the keratinizing hyperplasia.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.4
• /
• pp.685-690
• /
• 2008

In numerically evaluating the thermal performance of the heat exchanger, numerical values of thermodynamic properties such as temperature, pressure, specific volume, enthalpy and entropy are required. But the steam table or diagram itself cannot be directly used without modelling. In this study the applicability of neural networks in modelling superheated water vapor was examined. The multi-layer neural networks consist of an input layer with 2 nodes, two hidden layers with 15 and 25 nodes respectively and an output layer with 3 nodes. Quadratic spline interpolation was also applied for comparison. Neural networks model revealed smaller percentage error compared with spline interpolation. From this result, it is confirmed that the neural networks could be a powerful method in modelling the superheated water vapor.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.1
• /
• pp.36-41
• /
• 2012

We have been performed on $Co^{60}$ ${\gamma}$-ray irradiation of South Sea cultured pearls, with the absorbed dose of 0.1~100 kGy at room temperature. In addition, it was investigated electron paramagnetic resonance (EPR) and amino acid analysis (AAA) for detection of Gamma irradiated South Sea cultured pearls. It was observed that the irradiated South Sea cultured pearls revealed additional free radical peak such as $CO_2^-$, at a g-factor of $2.001{\pm}0.002$ in EPR spectra. From the amino acid analysis (AAA), it was shown that some of amino acid in the protein of the nacre destroyed after ${\gamma}$-ray; glutamic acid residue by 11.43 %, alanine by 3.11 %, and histidine by 43.75 %. It was useful to detect the irradiated South Sea cultured pearls by EPR measurement in our study.

• The Journal of the Petrological Society of Korea
• /
• v.19 no.1
• /
• pp.1-18
• /
• 2010

On the ArcGIS 9.2 program in Gyeongsangbug-Do and Daegu areas, distribution ratios of rock types and geologic ages were obtained from the 1 : 250,000 scaled digital geologic and geomorphic maps. The obtained distribution ratios here will be used the geologic information data for industrialization and development planning of rock resources. The Gyeongsangbug-Do area consists of 86 rock types that can be divided into 10 large groups in geologic age. Their geologic distribution ratios show the decreasing in the order of Cretaceous, Precambrian, Jurassic, Quaternary, Age-unknown and Tertiary, all of which occupy the prevailing ratio of 96.30% in the area. Of which, sixteen rock types are somewhat dominant ones (64.04%). They are of Precambrian Yulri group and granite gneiss of the Yeongnam metamorphic complex and biotite gneiss of the Sobaegsan metamorphic complex, Age-unknown granite, Jurassic granite, Cretaceous Gasongdong and Dogyedong formations of the Yeongyang sub-basin, Nagdong and Chunsan formations and intermediate-basic volcanics of Euiseong sub-basin, Jinju and Jindong formations and andesite-andesitic tuff of Milyang sub-basin, and hornblende granite, and Quaternary alluvium. They show relatively narrow ranges of 2.07-6.53% in geologic distribution in exception of Jurassic granite showing 13.14%. And the rest 70 rock types appear to very narrow range between 0.01 and 1.94 %. On the other hand, twelve rock types are developed in the Daegu area. Their geologic ages appear to be classified into Cretaceous and Quaternary occupying 86.05% and 11.39%, respectively. Seven rock types take possession of 94.04% among the all rocks. The major rock types are Jinju formation of the Sindong group, Chilgog, Haman and Jindong formations of the Hayang group, andesite and andesitic tuff, hornblende granite and Quaternary alluvium. With exception of andesite and andesitic tuff of 37.40%, the types show slightly wide range of 3.25-17.39%, which apparently differ trends from that of Gyeongsangbug-Do area. And the rest of rock types have narrow ranges of 0.22-1.81% in the Daegu area.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.1
• /
• pp.126-137
• /
• 2011

This study simulate three-dimensional ocean circulation patterns using the EFDC model in the Kwangyang Bay and Jinju Bay, considering tide, water temperature and salinity. The numerical model results were verified using observed data. The model results well reproduced the observed data. As a result, ocean circulation patterns in the study area show convergence and divergence in the middle area of Noryang waterway and Daebang waterway, the residual flow patterns show typical two-layer circulation. According to the change of the density stratification in the Kwangyang Bay and Jinju Bay, the effect of fresh water is dominant in study area. In the case of Jinju Bay, although it is strongly influenced by the Namgang fresh water, also it is affected by Seomjin River when there is no discharge by Namgang Dam. On the other hand, the stratification of the Kwangyang Bay is relatively enhanced by the discharge of Namgang Dam.

• The Korean Journal of Malacology
• /
• v.28 no.3
• /
• pp.245-254
• /
• 2012

This project analyzes distinct qualities of pearl cultured in Tongyeong by physical, chemical and optical test. The result is to provide scientific data for the value of pearl from Korean seawater. It divides one year pearl, which is used as a sample in the project, into white, natural blue and yellow gold colors, and then it has been divided into A, B and C based on the quality of the last results. A chemical experiment demonstrates that the higher quality has lower protein content of less than 10%. In another test called heavy metal content test, there is no big difference among classes. In the characterization of spectroscopy, it shows 280 nm peak indicated the conchiolin. It is clear that 407 nm, 430 nm and 460 nm peak are White group that are not in processed condition.

• Composites Research
• /
• v.23 no.4
• /
• pp.1-6
• /
• 2010

The dynamicresponse of biomimetic composites mimicking nacre under low velocity impact is investigated. The composites have hierarchical structures with a staggered pattern consisting of a protein and a mineral. To analyze the impact response of the composites, the finite element method is used. The effects of the hierarchical structures of the compositeson the dynamic response are examined. It is shown that the maximum stress, displacement and contact force in the composite subjected to low velocity impact decrease as the level of structural hierarchy increases.

• Journal of the Korean earth science society
• /
• v.33 no.6
• /
• pp.510-518
• /
• 2012

The Holocene climate change has been studied based on humus analysis of sediments that came from the Nam River basin in the Jinju, Gyeongnam. Humus and soil organic carbon analyses were performed to interpret the climate change and OSL dating and radiocarbon dating were conducted to determine the age of the sediments. The age determinations revealed that the sediments were formed approximately from $10,000{\pm}100$ yr. BP to $4,370{\pm}50$ yr. BP (2,970 BC) The deposits were classified into five layers based on sediments color and texture, and the climate change of each layer has been interpreted. The general climate was found out to be warm. The study result illustrated that section I was the lowest layer and section V the highest among the five surveyed sections. One the other hand, relatively cold events were detected in the sections ranging from I and II to III in terms of temperature. In term of humidity, sections II and III are estimated to have been relatively dry. Sections IV and V were relatively warm and dry, and the section IV tends to be warmest of the entire sedimentary. In addition, there is a tendency that the total soil organic carbon shows relatively high values under the cooler and humid climatic condition.

• Korean Journal of Heritage: History & Science
• /
• v.43 no.1
• /
• pp.236-259
• /
• 2010

The examination of sediment distribution in Seongryu Cave shows existence of rocks contrasting with Joseon Supergroup contrary to existing knowledge. Contrasting especially with the Taeback Group, Daegi Formation, Hwajeol Formation, and Dongjeom Formation has been observed. Unlike Taeback area where Dumugol Formation and Makgol Formation are observed on top of Dongjeom Formation, the rocks of this area are not clear in its separation between the two, so that it was named Geunnam Formation. Seongryu Cave has been developed in this Ordovician Geunnam Formation of the Joseon Supergroup. The cave, mostly horizontal, runs in the NE-SW direction, and contains three lakes. The main passage and branches are about 330 m and 540 m, respectively, making the total length of the cave about 870 m (show cave area = 270 m). Through underwater examination, about 85 m-long underwater passage was newly discovered. Various speleothem such as soda straw, stalactite, stalagmite, column, flowstone, rimston, cave shield, cave coral, curtain, bacon sheet, cave pearl, cave flower, helictite and calcite raft can be found in the cave. There are sections with constant flow of cavern water, but the majority of cavern water in the cave come from the ceiling. The most important discovery in this study is the presence of various speleothem in the submerged part of cave passages. Traces of corrosion and/or erosion can be observed in the speleothem in the submerge passage.

• Korean Journal of Heritage: History & Science
• /
• v.44 no.1
• /
• pp.4-29
• /
• 2011

Paleoenvironments of the shell deposit-bearing sequence in the Hasandong Formation at Daesong-ri area, Hadong-gun, Korea, are interpreted on the basis of sedimentary facies and taphonomy of the shell deposits, with a discussion of their stratigraphic implications. A shell deposit-bearing sequence without reddish beds is mostly grayish, and the bedding is laterally extensive. These deposits are interpreted to have been formed in sandflats, mudflats, and shallow lakes generated by flooding on an alluvial plain. The shell deposits are classified into three types according to the occurrence, and the concentration of a single species of Brotiopsis wakinoensis in the shell deposits is deemed to have been attributed to the exclusive inhabitation of the genus Brotiopsis. Type 1 and 2 shell deposits are interpreted to have been fossilized in sandflats and mudflats after death in their habitat of shallow lakes and subsequent transformation by sheetflooding and lake flooding. Type 3 shell deposits are interpreted to have been fossilized in their habitat of shallow lakes during a stabilized period of lake development. The development of the shell deposit-bearing lacustrine sequence in a few tens of meters in thickness in the Hasandong Formation of fluvial deposits is compared to the shift of depositional environments from the Hasandong Formation (fluvial deposits) through the Jinju Formation (lacustrine deposits) to the Chilgok Formation (alluvial plain deposits), which suggests that additional lithostratigraphic classification is needed in the Hasandong Formation. The shell deposits at the study area can provide valuable data to understanding the paleoenvironments during the Early Cretaceous Period of Korea, and should give basic data to evaluate the value of the Cretaceous mollusc deposits in Korea as a geological heritage.