• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.85-93
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• 2010

The shear stiffness has become an important design parameter to understand the soil behavior. In particular, the elastic moduli and void ratio has been considered as important parameters for the design of the geotechnical structures. The objective of this paper is the development of the penetration type Field Velocity and Resistivity Probe (FVRP) which is able to assess the elastic moduli and void ratio based on the elastic wave velocities and electrical resistivity. The elastic waves including the compressional and shear wave are measured by piezo disk elements and bender elements. And the electrical resistivity is measured by the resistivity probe, which is manufactured and installed at the tip of the FVRP. The penetration tests are carried out in calibration chamber and field. In the laboratory calibration chamber test, after the sand-clay slurry mixtures are prepared and consolidated. The FVRP is progressively penetrated and the data are measured at each 1 cm. The field experiment is also carried out in the southern part of Korea Peninsular. Data gathering is performed in the depth of 6~20 m at each 10 cm. The elastic moduli and void ratio are estimated based on the analytical and empirical solutions by using the elastic wave velocities and electrical resistivity measured in the chamber and field. The void ratios based on the elastic wave velocities and the electrical resistivity are similar to the volume based void ratio. This study suggests that the FVRP, which evaluates the elastic wave velocities and the electrical resistivity, may be a useful instrument for assessing the elastic moduli and void ratio in soft soils.

• Conservation Science in Museum
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• v.30
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• pp.1-22
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• 2023

This study aims to document the conservation treatment of the fine-hemp official headgear housed by the National Museum of Korea, and to reconsider its existing name following the restoration of the original form of the damaged cultural heritage asset. The headgear consists of a single inner frame with a vertical line at the front, a single outer frame surrounding the inner frame, and a double-layered headband that spans the circumference of the wearer's head and joins the inner and the outer frames. This study applied a conservation treatment to the men's undyed hemp headgear of the Joseon Dynasty in order to remove contaminants and foreign substances on the surface and repair the partially deteriorated and damaged fabric, thereby restoring and stabilizing the original shape and preparing it for exhibitions. The hemp headgear was sewed both by hand and with a sewing machine. Although its overall composition and style are similar to the same type of official headgear from the Joseon Dynasty, the use of a sewing machine supports the assumption that it was produced in the early 1900s. This study identified similarities between the overall composition and shape of the fully-preserved hemp official headgear and those of the jangbogwan, a type of men's official headgear worn by Confucian scholars as part of their everyday attire, and compared it with the shape of jangbogwan seen in documentary records, illustrations, prior research, and portraits from the Joseon Dynasty, as well as with the characteristics of extant jangbowan artifacts, eventually concluding that it is appropriate to classify and name the headgear as a jangbogwan.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.592-608
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• 2007

This study explored the types of conceptual change of 'force' within middle school students' conceptual ecologies. This qualitative study was implemented with the use of classroom observations and two interviews with the participants. 11 middle school students (7 females and 4 males) joined in this study. The interviews with the participants were conducted individually before and after the 'force' unit. The collected data were all transcribed and analyzed interpretively. The results of this study consisted of two parts. First, the participants' conceptual ecologies of 'force' were categorized into 4: epistemological commitments (fixed or interactional explanatory consistency), analogy (attribute, working), metaphysical beliefs (people-oriented ontology, animism, causationism, mixed), and past experiences. Second, two representative cases including 'stable' and 'transitional' states were explained based on the interactions within their own conceptual ecologies. We can see students' conceptions with the integrated perspective in the sense that this results tried to get contextual and interactional understandings of the status of the conception and the possibilities of conceptual change. In addition, it implied that conceptual change research should have the perspective of conceptual ecology evolution in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.3
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• pp.139-148
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• 2012

The short-term variation of salinity and temperature in a dyked estuarine environment is mainly controlled by the freshwater discharge from the dyke. We examined the distribution of salinity and temperature by the freshwater discharge in the Yeongsan River estuary using the CTD data obtained from 8 stations through three surveys in June (weak discharge) and August (intensive discharge), 2010. During the weak discharge in June, the surface salinity showed 30-32.5 psu and its horizontal gradient was relatively high around Goha-do (0.25~0.32 psu/km). On the other hand, the salinity of the bottom layer was almost constant in the range of 33 psu. Water temperature ranged $19{\sim}21^{\circ}C$ and displayed higher gradient in north-south direction than the gradient of east-west direction. During the intensive freshwater discharge on August 12, the salinity dropped to 9~26 psu. The maximum horizontal gradient of surface salinity reached 3.8 psu/km in the north of Goha-do where the strong salinity front was formed, and the horizontal salinity gradient of bottom layer was 0.28 psu/km. The horizontal gradient of water temperature was $-0.45^{\circ}C/km$ in the surface and $-0.12^{\circ}C/km$ in the bottom with high surface temperature near the dyke and decreasing gradually to the river mouth. After 3 days of the intensive discharge ($3^{rd}$ survey), the surface salinity increased to 22~26 psu. However, there still existed relatively high horizontal gradient around Goha-do. In the mean time, the bottom salinity decreased to 26.5~27.5 psu, but its gradient was not big as much as the surface gradient. According to time series of CTD profile near the dyke, the discharged fresh water jetted down temporarily and then recovered gradually with the recovering speed of 0.4 m/hour for the discharge case of $13{\times}10^6$ ton. Due to the combined effects of freshwater discharge and surface heating during the summer of 2010, the Yeongsan estuary, in general, underwent intensified vertical stratification, which in turn caused the inhibition of vertical mixing, especially inside area of estuary. Based on the spatial distribution of salinity and temperature, the Yeongsan estuary can be divided into three regions: the Goha-do area with strong horizontal gradient of salinity and temperature, inner estuary from Goha-do to the dyke with low salinity, and outer estuary from Goha-do to the coasts with relatively high salinity.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.257-268
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• 2003

The Cretaceous magmatism in the Gyeongsang Basin, Korea, led to the formation of two contrasting metallogenic provinces: the Haman-Gunbug-Goseong(-Changwon) (HGGC) and the Euiseong (EU). The mineralization in the HGGC metallogenic province represents copper, gold and iron of porphyry-related deposits that display close relationships in time and space with subvolcanic granitoids. Much of copper-gold-forming events in this province are consistently constrained to the period between ca. 89 and 81 Ma. The hydrothermal systems of copper-gold vein deposits in the HGGC province are associated with ore-forming fluids of high to intermediate temperature (300∼50$0^{\circ}C$) with high salinity (20∼55 equiv. wt. % NaCl). The ore-forming fluids become progressively more diluted by the incorporation of decreased quantities of magmatic water further from the nearby intrusion, suggesting significant input and fluid mixing of a meteoric water component to the magmatic fluids during the late stage of geothermal systems. In contrast, the EU metallogenic province is characterized by polymetallic vein deposits that are consistently constrained to a period of 78∼60 Ma. The geothermal systems of polymetallic vein deposits in the EU province are derived from a narrow range of intermediate temperature (200∼40$0^{\circ}C$) with relatively low salinity(1∼7 equiv. wt.% NaCl). It may represent a mixed fluid of magmatic and meteoric waters. The base-metal mineralization in the Gyeongsang Basin shows a close spatial and temporal distinction between the proximal environment derived from shallow-level granitoids in the southwestern HGGC province and the distal condition derived from volcanic environments in the northwestern EU province.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.305-310
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• 2004

The present study was aimed at investigating effects of chicory inulin and three kinds of oligosaccharides on lipid metabolism in rats fed a high-cholesterol diet. Nine Sprague-Dawley male rats weighing, about 190g were given one of five experimental diets, which were basal cholesterol diet (Control) isomaltooligosaccharide diet (IMO), Iructooligosaccharide diet (FO), chicory inulooligosaccharide diet (CIO) and chicory inulin diet (CI) for 5 weeks. In the oligosaccharide and inulin diets, 6% was added at the expense of sucrose. Rats were pair-fed to the intake of FO group which consumed the least amount, and their feces were collected during the last 4 days. Body weight gain was lower in Fo and CI groups compared with the Control group. Plasma glucose levels of FO and CIO groups were lower and plasma triglyceride concentrations of FO, CIO, and CI groups were lower than those of IMO group. Plasma cholesterol concentration did not differ among groups. Relative liver weight was lower in CIO group. Hepatic triglyceride and cholesterol did not differ among. groups. Fecal excretion of neutral steroid and bile acid were not different among groups, but fecal triglyceride excretion was significantly increased in FO and CI groups compared with the Control group. In conclusion, supplementation of oligosaccharides and chicory inulin at 6% of diets showed no significant hypolipidemic effect in rats fed a high cholesterol diet.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.1-15
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• 2014

The Bobonaro m$\acute{e}$lange is one of the youngest syn-collisional m$\acute{e}$langes, located between the Indo-Australian and Eurasian plates. The m$\acute{e}$lange has formed in association with a collision between the Australian continental margin and the Banda arc initiated in Neogene. The Suai area at the southern part of Timor is a good place to examine the genetic relationship between the m$\acute{e}$lange and other rock sequences because various tectonostratigraphic units coexist in the area. In this study, we present the structural characteristics and spatial distribution of the Bobonaro m$\acute{e}$lange investigated as a part of 1:25K scale geologic mapping in the area, and discuss on the origin of the m$\acute{e}$lange. The Bobonaro m$\acute{e}$lange in the Suai area is composed of unmetamorphosed clay matrix and blocks of various lithologies. The clay matrix mainly is reddish brown or greenish gray in colour, and has scaly texture. Most blocks are allochthonous, but mostly derived from nearby formations. Based on the internal structure and relationship with surrounding rocks, the Bobonaro m$\acute{e}$lange is genetically classified into 1) diapiric m$\acute{e}$lange; 2) tectonic m$\acute{e}$lange; and 3) broken formation. The spatial distribution of the Bobonaro m$\acute{e}$lange indicates that it intruded all pre-collisional units including the lower Australian continental margin unit(Gondwana megasequence) and the Banda arc unit. Taking the field evidences and previous genetic models into consideration, the Bobonaro m$\acute{e}$lange is interpreted to be mainly formed as a diapiric m$\acute{e}$lange originated from Gondwana megasequence, consistently effected by faulting events. This study reflects that diapiric m$\acute{e}$lange is a significant component in recent accretionay-collision belts. It suggests that diapiric process should be considered as a main genetic factor even in ancient m$\acute{e}$lange.

• (The)Study of the Eastern Classic
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• no.69
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• pp.179-204
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• 2017

Hojil(虎叱) and Yangbanjeon(兩班傳) reveal the characteristic styles of Park Jiwon(朴趾源)'s writing, which is combining styles of unofficial history/biography(外傳) and allegory(寓言), and full of the senses of satire and humour which form another characteristc of his writing style or tone. This paper reexamines narrative styles, meaning structures and themes of these two works which combine the styles of unofficial history/biography and allegory, and researches methods and techniques of allegory and satire which presents the subversive and critical themes and thoughts of the author. In Hojil, combining of the two styles, the author constructs the narrative world and plot, manipulates allegoric figures to symbolize and present multilayered meaning, and criticize the decadence of confucian aristocracy [Sadaebu: 士大夫] and it's abuses. In Yangbanjeon by combining of two styles, the author weave a biography of Yangban(兩班) in general, which presents the attributes and historical position of the Yangban class. And by the nonsensical fictional event which caricatures crisis of the Yangban class, and tedious description of the manners and behaviors of the Yangban, the author and satires the snobbery of the Yangban and the absurdity of their classical privileges. As he did in Hojil, the author urges the self-examination of the reader raising a question about the position and the function or duty of the Yangban class in the changing world. And the various skills of satire together with the irony, paradox, parody and pun were used dexterously in above two works.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.117-123
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• 2021

In this study, the composite was prepared by mixing SiOx, soft carbon, and carbon black and the electrochemical properties of lithium ion battery were investigated. The content of SiOx added to improve the capacity of the soft carbon anode material was varied to 0, 6, 8, 10, 20 wt%, and carbon black was added as a structural stabilizer for reducing the volume expansion of SiOx. The physical properties of prepared CB/SiOx/C composite were investigated through XRD, SEM, EDS and powder resistance analysis. In addition, the electrochemical properties of prepared composite were observed through the charge/discharge capacity, rate and impedance analysis of the lithium ion battery. The prepared CB/SiOx/C composite had an inner cavity capable of mitigating the volume expansion of SiOx by adding carbon black. The formed internal cavity showed a low initial efficiency when the SiOx content was less than 8 wt%, and low cycle stability when the content of SiOx was less than 20 wt%. The CB/SiOx/C composite containing 10 wt% of SiOx showed an initial discharge capacity of 537 mAh/g, a capacity retention rate of 88%, and a rate of 79 at 2C/0.1C. SiOx was added to improve the capacity of the soft carbon anode material, and carbon black was added as a structural stabilizer to buffer the volume change of SiOx. In order to use the CB/SiOx/C composite as a high-efficiency anode material, the mechanism of the optimal SiOx and the use of carbon black as a structural stabilizer was discussed.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1027-1034
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• 2007

This research was focused on the selective separation of $CO_2$ or $CH_4$ from mixture of these gases, by controlling the size of pore or pore gate. Pitch based activated carbon fibers(ACF) were used as adsorbents. The size of pore gate was controlled by the molecule having similar size to that of pore opening. After the adsorption of adsorbate on pore surface, planar molecules such as benzene and naphthalene covered the pore gate. The slow release of adsorbate from the pores covered by planar molecules makes apertures between planar molecules covering pore gate and this structure can be fixed by rapid pyrolysis. The control of pore gate using benzene as covering molecules could not accomplished due to the simultaneous volatilization of benzene and adsorbate$(CO_2)$ caused by similar temperatures of benzene volatilization and adsorbate desorption. Therefore we replaced benzene with naphthalene looking for the stability at a $CO_2$ desorption temperature. The naphthalene molecule was adsorbed on the ACF up to 15% of ACF weight and showed no desorption until $100^{\circ}C$, indicating that the molecule could be used as a good cover molecule. Naphthalene could cover almost all the pore gate, reducing BET surface area from 753 $m^2/g$ to 0.7 $m^2/g$. A mixed gas$(CO_2:CH_4=50:50)$ was adsorbed on the naphthalene treated OG-7A ACF. The amount of $CO_2$ adsorption increased with total pressure, whileas thai of $CH_4$ was not so much influenced on the pressure, indicating that $CO_2$ made more compounds on the ACF surface along with total pressure increase. The most $CO_2$ and the least $CH_4$ were adsorbed in the condition of 0.4 atm, resulting in the highly pure $CH_4$ left in ACF.