• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.555-566
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• 2006

Major, trace and rare earth elements data of the Cretaceous Jindong granitic rocks were investigated in order to constrain the magma source characteristics and to establish the paleotectonic environment of the southwestern part of the Gyeongsang Basin. Geochemical signatures of the granitic rocks from the study area indicate that all of the rocks have characteristics of calc-alkaline series in the subalkaline field, and progressively shift from metaluminous to peraluminous with differentiation. In the variation diagrams, the overall geochemical features of the granites show systematic variations in major and trace elements. Chondrite normalized REE patterns show generally enriched LREE((La/Yb)c=4.2-12.8) and slight negative to flat Eu anomalies. Rb-Sr isotope data of the Jindong granites show that the whole rock age and Sr initial ratio are $114.6{\pm}9.1Ma$ and 0.70457, respectively. The Sr initial ratio of the Jindong granites is very similar to those of the Creataceous granites from Masan, Kimhae and Busan area($^{87}Sr/^{86}Sr=0.7049-0.707$). These results suggest that the magma have the mantle signature and intruded into the area during the early Cretaceous age. The Jindong granites have higher $Al_{2}O_{3},\;Na_{2}O$, Sr and lower $K_{2}O$, Y concentrations compared with typical calc-alkaline granitic rocks. These adakitic signatures are similar to those of adakitic pluton on Kyushu Island, southwest Japan arc. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG granite. Interpretations of the geochemical characteristics of the granitic rocks favor their emplacement at continental margin during the subduction of Izanagi plate.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.223-236
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• 2007

The eastern extension of the Cordilleran-type orogenic belt continues from southeastern China to the Chukot Peninsula through the Korean Peninsula. The Gyeongsang basin, located in the southeastern part of the Korean Peninsula and the Inner Zone of southwest Japan are characterized by extensive distribution of Cretaceous to Tertiary I-type calc-alkaline series of intrusive rocks. These intrusive rocks are possibly the result of intensive magmatism which occurred in response to the subduction of the Izanagi Plate beneath the northeastern part of the Eurasian Plate. The Jindong granitoids within the Gyeongsang basin are reported to be adakites, whose signatures are high $SiO_2,\;Al_2O_3$, Sr, Sr/Y La/Yb and, low Y and Yb contents. The major and trace element contents of the Jindong granitoids fall well within the adakitic field, whereas other Cretaceous granites in the same basin are plotted in the island arc ADR area in discrimination diagrams. Chondrite normalized REE patterns show generally enriced LREEs (La/Yb)C = 3.6-13.8) and slight negative to flat Eu anomalies. The mean Rb-Sr whole rock isotopic age of the Jindong granitoids is $114.6{\pm}9.1$ Ma with an initial Sr isotope ratio of 0.70457. These values suggest that the magma has mantle signature and intruded into the area during Early Cretaceous. The Jindong granitoids have similar paleogeographical locations, paleotectonic environments and intrusion ages to those of the Shiraishino granodiorites of Kyushu Island and the Tamba granitoids of San'yo belt located on southwestern Japanese arc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.648-658
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• 2003

As the usage of image/video contents increase, a security problem for the payed image data or the ones requiring confidentiality is raised. This paper proposed an image encryption methodology to hide the image information. The target data of it is the result from quantization in wavelet domain. This method encrypts only part of the image data rather than the whole data of the original image, in which three types of data selection methodologies were involved. First, by using the fact that the wavelet transform decomposes the original image into frequency sub-bands, only some of the frequency sub-bands were included in encryption to make the resulting image unrecognizable. In the data to represent each pixel, only MSBs were taken for encryption. Finally, pixels to be encrypted in a specific sub-band were selected randomly by using LFSR(Linear Feedback Shift Register). Part of the key for encryption was used for the seed value of LFSR and in selecting the parallel output bits of the LFSR for random selection so that the strength of encryption algorithm increased. The experiments have been performed with the proposed methods implemented in software for about 500 images, from which the result showed that only about 1/1000 amount of data to the original image can obtain the encryption effect not to recognize the original image. Consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. Also, in this paper, several encryption scheme according to the selection of the sub-bands and the number of bits from LFSR outputs for pixel selection have been proposed, and it has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Journal of Sericultural and Entomological Science
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• v.13 no.1
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• pp.23-29
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• 1971

As a result of analyzing the change of material substance of all sorts biochemically and comparing the control with ${\gamma}$-ray irradiation (800${\gamma}$, 40 Min), incubating the silkworm eggs (Bombyx mori L.) as the objective in the process of growth of embyro shortly before hatching, the following conclusion has been found. 1. Ascorbic acid has shown the maximum increase of 319 r/g in the Byong B embyro stage and in other words it has increased during the period of vigorous metabolism of the materials in eggs but it has decreased before hatching after that period. 2. Triglyceride has shown the increase of 27.54 mg/g in the Byong A stage, the early period of incubation and in other words it has increased in the period of activation of cells in eggs but it has gradually decreased during the growth of embyro after that period. Great change of either total cholesterol or free cholesterol has not been shown from the early period till shortly before hatching. 3. Free fatty acid has shown the minimum decrease of 257.4$\mu$ mole/g in the Byong A stage in which triglyceride increases greatly. On the contrary, it has shown the increase of 1, 020.0$\mu$ mole/g in Ki A stage in which triglyceride decreases. As a whole, the fact that free fatty acid increases according to the growth of embyro in eggs has been found. 4. Glucose has shown the increase of 281.2 mg/g in control during tile Pigment stage and it has shown the increase of 179.6 mg/g in ${\gamma}$-ray irradiation during the same period. The difference in quantity between the former and the latter is due to the fact that the growth of embyro has been influenced by the radio active. Glucose has changed with free fatty acid and phosphorus the other way round. 5. Control organic phosphorus has shewh the increase of 5.23mg/g during the Byong B or Ki A in which organ and tissue in the emhyro has been formed. Organic phosphorus in ${\gamma}$-ray irradiation has shown the increase of 5.73mg/g during Ki B. Inorganic phosphorus has shown only a little change in the control and ${\gamma}$-ray irradiation. The phosphorus in both has shown a little quantity in the ${\gamma}$-ray irradiation in the early period of incubation. After the Ki A embyro, it has increased rapidly and it has increased till the hatching more continually than in control. The about results of the research will be helpful and instructive to the betterment and improvement, breeding and management of animals and plants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.1
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• pp.20-31
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• 2002

This study was carried out to investigate the composition and the distribution of the benthic polychaetous communities in Deugryang Bay, semi-enclosed bays, on the southern coast of Korea and to deduce temporal changes in community with the comparison of the past studies. In Deugryang Bay, benthic polychaetous community structure was investigated on the base of the samples from 98 stations in 1996 and 1997. The main facies of surface sediment was clayey silt. The overall benthic macrofaunal density was 871 ind./m$^{2}$. The density was highest in the middle part of the bay because Musculus senhousia (Bivalvia) and cumaceans (Crustacea) had their highest densities in some stations. Benthic polychaetes were comprised of 100 species with a mean density of 138 ind./m$^{2}$. Their abundances were higher in the inner bay, in the middle bay, and in the mouth of bay, but poor community structures were established in the whole bay. The dominant species over 1.0 percentage were composed of the total 21 species, and they occupied 78.3% of the total abundance of the benthic polychaetes. The most dominant species was Lumbrineris longifolia (9.3%), followed by Eteone longa (7.3%), Heteromastus filifomis (7.1%), Sternaspis scutata (6.1%). From the cluster analysis, the study area could be divided into three station groups. Station group AI was located in the inner bay and in the shallow coastal region, and its most dominant species was Heteromastus filiformis. At the station group AII in the mouth of bay and in some channel region, its most dominant species were Lumbrineris longifolia and Eteone longa. And at the station group B located in middle part of the bay, the most dominant specis was Sternaspis scutata. In comparison with previous studies, the benthic polychaetous community experienced great change in the view of species number, density and dominant species. The dominant species were Sternaspis scutata and Eteone longa, but their densities declined greatly. Instead of these species, Lumbrineris longifolia and Heteromastus filiformis, known as the potential organic enrichment indicator species, appeared to the new dominant species even if their low densities. These facts mean that Deugryang Bay was maintained yet as little organic enriched area compared to other bays on the coast of Korea, but needed some caution of marine environmental management.

• The Journal of the Petrological Society of Korea
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• v.15 no.4 s.46
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• pp.167-179
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• 2006

Division of granites in the Galmal-Yeonbug area, northern Gyeonggi, can be grey hornblende biotite granite (JHBG), biotite granite (JBG) and pink hornblende biotite granite (CHBG) by lithofacies. JHBG of small stock occurs as medium-grained with grey color and minute sphene. JBG occurs as medium-grained and light grey to grey in the north-east part of the area. The main study target CHBG covers in the north-southeast part of the area, and occurs medium-to coarse-grained with pink color. CHBG shows partly minute miaroles, and pegmatitic pocket with druse texture. From the mineral age data (K-Ar method). JHBG and JBG and CHBG are the igneous activity products of Daebo orogeny with different Jurassic and Bulgugsa disturbance of Cretaceous, respectively. And the age data also agree with geologic occurrences and interpretations of the granites in the field. CHBG consists of quartz, plagioclase, alkali-feldspar, biotite, hornblende, allanite, apatite, zircon, some calcite and opaques. Among them, alkalifeldspar and calcite occur characteristically in mostly perthitic othoclase and secondary filling of minutely miarolitic cavity, respectively. In modal analysis and QAP diagram, CHBG plots in granite field, and especially boundary of monzo-and syeno-granite fields. From the major oxide variations, molar A/CNK, $SiO_{2}\;vs\;K_{2}O$, AMF and so on, CHBG belongs to the acidic, peraluminous and high-K calc-alkaline, and was late differentiation product of single granitic magma. Barium and strontium have also dominantly differentiation trend, and in CaO vs Sr and $K_{2}O$ vs Sr, Sr was more participitated in the fractionation of plagioclase than that of alkali-feldspar. Normalized REE concentrations to chondrite value have parallel and gradual LREE enrichment and HREE depletion patterns, and weak Eu negative anomalies and narrow ranges of normalized Eu can suggest that plagioclase fractionations occurred mildly in the whole CHBG.

• Journal of the Korean association of regional geographers
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• v.5 no.2
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• pp.47-117
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• 1999

This study concern with the pattern of Pusan Station shopping district within Pusan City, Korea, one of the special functioned shopping district within Pusan City. This paper will serve as a part of series studies which attempt to clarify the internal structure of Pusan as a whole. Part(II) of this study deals with the functions including living related, restaurants and others. The pattern of floors, size of shops, street corners and widths of streets were also analysed. The results are as follows: 1. In terms of numbers of firms in living related function, Pusan Station shopping district is the $7{\sim}8th$ ranked central place among nine the highest centers within Pusan City. Pusan Station shopping district has not much promoted vertical spatial differentiation comparatively, and also it's intensity of land use is the lower among nine the highest centers. It is presented that intimate relationship between intensity of vertical land use and classes of central places within the city. The ratio of inns and hotels in Pusan Station shopping district is third ranked in Pusan City. And the size of inns and hotels in this area is the most largest among the nine highest ranked central places within Pusan City. These presented that the traditional characteristics of station area as a special functioned shopping district. Inns and hotels mainly located along the narrower and back street. And it forms agglomerated areas or 'an alley of inns' at the inner parts of blocks, some like a 'hidden flower'. In Korea, 'alley' means that an area of specialization gains the prestige, traditionally. 2. Restaurants mainly locate along the narrower and back streets. And agglomerated areas of restaurants coincide with the agglomerated area of drinking places. It shows that these two kinds of functions need the same locational conditions. The ratio of Chinese restaurants is the highest in the Pusan Station shopping district. It's due to the agglomerated area these kinds of restaurants at the 'China town'. 3. Pusan Station shopping district has been formed along the streets within the residential areas. It's means that this shopping district now at the initial or middle growth era in development stage of shopping areas. 4. In general, wholesales and light manufacturing are located at peripheries within shopping district. But in Pusan Station shopping district, it dose not appear these spatial pattern. It shows that this area is lower ranked central place and not much progressed in spatial differentiation. 5. Particular firms which customers and workers have stayed more longer period of time are located at the far from the first floor. This vertical spatial differentiation is similar to the horizontal sequences. 6. Firms which have more ability of rental payment are located at street comers such as banks and pharmacies. In Pusan Station shopping district commercial facilities could not invade into the second third floors at narrower streets and first floor of back streets, still now.

• Journal of the Korean association of regional geographers
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• v.22 no.1
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• pp.151-167
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• 2016

Conventional social science typically regards the idea of a 'mountain' as part of 'nature' and a physical environment existing separately from, or prior to, human society and culture. However, in Korea, which is 70% mountainous land, the 'mountain' is part of a unique 'social nature'. This research develops the idea that in this context the mountain is a social nature and a cultural landscape which are tied heavily to the idea of travel. The article interrogates why the scenic beauties of Mt. Kumgang have been perceived and conveyed through multiple generations since the Chosun Dynasty period. Focusing on Mt. Kumgang, this article illustrates how strongly people have held dreams of mountain travel, for the whole life-time. Travel writings(or accounts of trips to the mountain) and artwork have played a particularly important role in creating Mt. Kumgang's reputation as the most beautiful mountain in the country. At the same time, the access to the mountain was often a dangerous adventure, with many travelers facing hunger and extreme physical challenges. As portrayed in writings and artwork, the overall effect of these dynamics was the creation of a socionatural place of striking beauty that even seemed to have mystical or magical fantasy. According to Confucian ideals, full appreciation of nature and its beauty was key to understanding the logics of the universe and to achieving a high moral standard, which contributed to decide to leave for the mountain as well. The essays, poems, and paintings of Mt. Kumgang since the Chosun Dynasty period that portrayed the mountain's beauty collectively served to produce the mountain as a socionatural landscape engendered with potent place-myths, important historical meaning, and strong aesthetic associations. Thus, the travel to the mountain seemed never completed over until travelers had completed various artistic representations to record and to memorize what they'd done and seen in Mt. Kumgang, which had been performed for the strong purpose of social sharing of the real the mountain's beauties and itinerary.

• Journal of the Korean earth science society
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• v.30 no.4
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• pp.427-443
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• 2009

Cretaceous intrusive and extrusive rocks in the southwestern part of the Yeongnam Massif are possibly the result of intensive magmatism which occurred in response to subduction of the Pacific plate beneath the northeast portion of the Eurasian plate. Geochemical and petrological study on the granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. The granodiorites distributed around Donggyori in the Bognae area (DGd) are different from other granitic rocks within the study area in the contents and differentiation trends of $Al_2O_3$ and MgO as well as in the contents of the trace elements such as Ba, Sr, Pb, Ni, Cr and Y DGd have geochemical features similar to slab-derived adakites such as high $Al_2O_3$, Sr contents and high Sr/Y, La/Yb ratios, but low Y and Yb contents. The major and trace element contents of the DGd fall well within the adakitic field, whereas other Cretaceous granites in the study area are plotted in the island arc ADR area in Sr/Y vs. Y diagram. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite (VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of Pacific plate. The geochemical and tectonic features reveal that adakite-like signatures of the DGd were generated by the interaction of mantle peridotite and subducted slab-derived adakitic melts (caused by the thermal effect of ridge subduction), and which slightly modified by crustal contamination during emplacement.