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Despite the development of various AIsystems to support learning in various domains, AIassistance for art appreciation education has not been extensively explored. Art appreciation, often perceived as an unfamiliar and challenging endeavor for most students, can be more accessible with a generative AI enabled conversation partner that provides tailored questions and encourages the audience to deeply appreciate artwork. This study explores the application of multimodal large language models (MLLMs) in art appreciation education, with a focus on developing LLaVA-Docent, a model designed to serve as a personal tutor for art appreciation. Our approach involved design and development research, focusing on iterative enhancement to design and develop the application to produce a functional MLLM-enabled chatbot along with a data design framework for art appreciation education. To that end, we established a virtual dialogue dataset that was generated by GPT-4, which was instrumental in training our MLLM, LLaVA-Docent. The performance of LLaVA-Docent was evaluated by benchmarking it against alternative settings and revealed its distinct strengths and weaknesses. Our findings highlight the efficacy of the MMLM-based personalized art appreciation chatbot and demonstrate its applicability for a novel approach in which art appreciation is taught and experienced.

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Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the US. Understanding the mechanisms of CRC progression is essential to improve treatment. Mitochondria is the powerhouse for healthy cells. However, in tumor cells, less energy is produced by the mitochondria and metabolic reprogramming is an early hallmark of cancer. The metabolic differences between normal and cancer cells are being interrogated to uncover new therapeutic approaches. Mitochondria targeting PTEN-induced kinase 1 (PINK1) is a key regulator of mitophagy, the selective elimination of damaged mitochondria by autophagy. Defective mitophagy is increasingly associated with various diseases including CRC. However, a significant gap exists in our understanding of how PINK1-dependent mitophagy participates in the metabolic regulation of CRC. By mining Oncomine, we found that PINK1 expression was downregulated in human CRC tissues compared to normal colons. Moreover, disruption of PINK1 increased colon tumorigenesis in two colitis-associated CRC mouse models, suggesting that PINK1 functions as a tumor suppressor in CRC. PINK1 overexpression in murine colon tumor cells promoted mitophagy, decreased glycolysis and increased mitochondrial respiration potentially via activation of p53 signaling pathways. In contrast, PINK1 deletion decreased apoptosis, increased glycolysis, and reduced mitochondrial respiration and p53 signaling. Interestingly, PINK1 overexpression in vivo increased apoptotic cell death and suppressed colon tumor xenograft growth. Metabolomic analysis revealed that acetyl-CoA was significantly reduced in tumors with PINK1 overexpression, which was partly due to activation of the HIF-1α-pyruvate dehydrogenase (PDH) kinase 1 (PDHK1)-PDHE1α axis. Strikingly, treating mice with acetate increased acetyl-CoA levels and rescued PINK1-suppressed tumor growth. Importantly, PINK1 disruption simultaneously increased xenografted tumor growth and acetyl-CoA production. In conclusion, mitophagy protein PINK1 suppresses colon tumor growth by metabolic reprogramming and reducing acetyl-CoA production.

The goal of this study is to explore the perceptions of teachers in Korean rural schools regarding teaching and learning, including technology preparedness, performance, demanding activities, difficulties, and continuing integration in tablet-based interactive classrooms. A survey instrument was designed, and responses were analyzed from 54 teachers who participated in a social contribution project for rural schools. The results indicate that student preparedness is significantly correlated with the frequent integration of tablets in classroom lessons. Furthermore, the most frequent types of pedagogical activities performed using tablets in the classroom are activities intended to motivate students. Teachers noted that their continuing integration of lessons with tablets was correlated with their beliefs about the applicability of tablets for lessons, students’ satisfaction with previous lessons, students’ expectations and requests, and the teacher’s personal interests. This research contributes to the literature on tablet integration by extending existing findings to the study of rural schools with limited educational resources. Moreover, this study provides implications for educators and school administrators who are interested in supporting teachers and their instruction using tablets and relevant technologies.

Abstract: Zircon U-Pb geochronology was applied to a migmatitic gneiss in the Busan gneiss complex, Gyeonggi massif, Korea. 207Pb/206Pb ages of concordant zircon grains reveal that overgrowth rims with Th/U ratios lower than 0.1 formed at 1937 ± 6 Ma during the migmatization and mantled the inherited cores of ca. 3500–2200 Ma. The 207Pb/206Pb age of the rims is consistent with the monazite Th-total Pb age (ca. 1938 Ma), suggesting that the rims are the product of Paleoproterozoic regional metamorphism. Our zircon age data are not sufficient for discerning the tectonic affinity of the Busan gneiss complex belonging to either Gyeonggi or Yeongnam massif. However, consistency of these ages with the ca. 1930 Ma Pb-Pb age reported from the Bagdalryeong gneiss complex, Gyeonggi massif, supports the tectonic model that the Busan gneiss complex is a part of the Gyeonggi massif. Discordant U-Pb data obtained from the zircon rims (293 ± 31 Ma) and the monazite Th-total Pb age (ca. 289 Ma) suggest that the Busan gneiss complex was affected by the Early Permian regional metamorphism during the Ogcheon (Okcheon) Orogeny. Therefore, we conclude that the Busan gneiss complex is a part of the Gyeonggi massif occurring as either a basement rock of the Ogcheon (Okcheon) metamorphic rocks, or a tectonically emplaced, exotic piece affected by the Early Permian Ogcheon (Okcheon) metamorphism. In addition, our U-Pb data suggest that the Busan complex is possibly linked with the Hida-Oki terrane in Japanese Islands.

Abstract: We discovered the oldest rock in South Korea, and dated this migmatite using a Sensitive High-Resolution Ion Micro-probe (SHRIMP). Zircon grains from a tonalitic migmatite, Daeijak Island, western Gyeonggi massif, are distinctly zoned and commonly characterized by oscillatory-zoned cores and structureless rims. The U-Pb zircon ages estimated from six spot analyses of the rims in five grains define a concordant age group with the weighted mean 207Pb/206Pb age of 2508 ± 18 Ma, interpreted as the age of migmatization. On the other hand, the cores yield an older 207Pb/206Pb age of ca. 2.58 Ga, interpreted as the crystallization age of tonalitic protolith. These results demonstrate not only the presence of Neoarchean granitoids but also high-grade migmatitic metamorphism at ca. 2.51 Ga in the Gyeonggi massif, which are correlative with those reported from the North China craton.

Abstract: We report in-situ Hf isotopic data on five inherited zircon components, dated at > 3.0 Ga from previous Sensitive High Resolution Ion Microprobe (SHRIMP) U-Pb analyses. These data are useful for constraining the timing and nature of very pristine crustal materials in South Korea.176Hf/177Hf isotope ratios, measured using a laser ablation Multi-collector Induced Coupled Plasma Mass Spectrometer (MC-ICP MS), range from 0.28044 to 0.28075, corresponding to the present-day εHf(0) of −70 to −81. They yield two-stage Hf model ages of ca. 4.1 to 3.5 Ga at the time of zircon crystallization from a magma, depending on tenable crustal evolution models. Our results provide the first Hf isotopic evidence for existence of Paleoarchean (>3.5 Ga) crustal components in the Korean Peninsula.

Abstract: This study focuses on the depositional and deformational features of quartzite-shale and phyllite beds in the lower part of the Seochangri Formation, Okcheon Group, mid-Korea. Each quartzite unit (25–320 cm thick) is massive, whereas the overlying laminated shale unit (0.5–10 cm thick) is either homogeneous or slightly laminated. Although these interbeds were strongly deformed under brittle-ductile conditions (ca. 300°C), the quartzite units show a thickening-upward trend. The quartzite-shale interbeds represent deposition from turbidity currents, i.e., Bouma-A and-D/E divisions. The thickening-upward quartzite-shale units are suggestive of progradation of sand lobes in the middle-outer fan. The overlying phyllite beds with thin quartz interlayers most likely represent outer fan and basinplain environments. The Seochangri Formation in the Bonghwajae section forms a thrust front against the limestone and dolomite beds of the Joseon Supergroup in which the quartzite-shale units are overlain by the phyllite beds and, in turn, underlain by the folded limestone beds. The phyllite and limestone beds were strongly deformed, showing upright isoclinal to tight folds, sheath folds, and boudins. The fold axes generally trend north-northeast with a low plunge angle. The thrust front represents part of the restraining bend of a dextral fault, the South Korean Tectonic Line. It is the major structural discontinuity between the Okcheon Group (Proterozoic) and the Joseon Supergroup (Lower Paleozoic). The collisional offset between the Gyeonggi Massif (South China Block) and the Yeongnam Massif (Sino-Korean Block) most likely occurred in the Jurassic prior to the emplacement of the mafic dyke and amphibolite.

The Ogcheon metamorphic belt (OMB), which is often correlated with the Dabie-Sulu ultrahighpressure (UHP) belt in China, comprises Neoproterozoic to Paleozoic metasedimentary and -volcanic sequences representing a stack of synmetamorphic nappes. Regional metamorphic grade increases northwestward to produce the assemblage, biotite + garnet ± staurolite ± kyanite + plagioclase + quartz. Garnet porphyroblasts show chemical zoning typical for prograde metamorphism, with decreasing Mn and increasing Fe and Mg from core to rim. P-T conditions were estimated to be 4.2-9.4 kbar and 490-630°C, corresponding to the medium-pressure type. In addition, the GIBBS calculation suggests a clockwise P-T-t path, corroborating a crust-thickening event associated with regional peak metamorphism. Using various isotopic techniques, the timings for intracontinental rift volcanism and syntectonic metamorphism were determined. New SHRIMP U-Pb zircon ages from a felsic tuff reflect the Neoproterozoic rifting at ~;750 Ma. Regional metamorphism has been recently dated at ~;285 Ma, based upon several independent sets of radiometric ages: U-Pb ages of monazite inclusions in garnet, Pb-Pb whole-rock ages of black slates, chemical ages of uraninite, and SHRIMP U-Pb zircon ages from a granitic gneiss pebble in metadiamictite. Thus, the Ogcheon orogeny is newly defined as an earliest Permian event, preceding a high-pressure metamorphic event in the Imjingang belt, central Korea, by ~;30 Ma. During the subsequent Songrim orogeny, at ~;250-220 Ma, the OMB experienced a second regional-thermal metamorphism under greenschist-to amphibolite-facies conditions. This Triassic event is interpreted to correspond to a major collisional orogeny in the Dabie-Sulu belt. These multiple metamorphic events in the Ogcheon belt are readily correlated with those reported from not only the UHP belt in east-central China, but also the Hida and Renge belts in Japan. Thus, eastward extension of the Dabie-Sulu belt through the Korean Peninsula to the Hida belt (Ernst and Liou, 1995) remains a valid hypothesis.

Zircon grains separated from a granitic gneiss boulder of the Hwanggangri Formation, Ogcheon metamorphic belt, were analyzed using a SHRIMP II ion microprobe. This gravel-bearing formation consists primarily of greenschist to amphibolite facies metadiamictites. U−Pb zircon ages obtained from 31 grains provide not only diachronous inheritance ages ranging up to ca. 2.5 Ga but also define an apparent discordia with upper and lower intercept ages of ca. 1.87 Ga and ca. 290±40 Ma, respectively. The former age is consistent with the Paleoproterozoic age of granu-lite-facies metamorphism and granitic magmatism in the Gyeonggi and Yeongnam massifs. However, the latter age has not been reported from the basement gneisses and may be attributable to significant Pb loss during the Late Carboniferous Ogcheon orogeny recently dated at ca. 290–280 Ma. Alternatively, multiple Pb loss episodes including a ca. 400 Ma thermal disturbance may account for the array of discordant data. The tectonic implications for each hypothesis are enormous for deciphering the evolution of the Ogcheon belt, but precise interpretation awaits further geochronologic analyses.

In order to understand the nature of noble gas reservoirs beneath continents, elemental and isotopic compositions of noble gases were analyzed from spinel-lherzolites with anhydrous mineral assemblages (i.e., olivine+clinopyroxene+orthopyroxene +spinel±apatite±garnet); these are considered to be typical of the upper lithospheric mantle. Isotopic compositions of the noble gases were measured for peridotite xenoliths enclosed in Cenozoic alkaline basalts in eastern-central China to provide insight on mantle characteristics. The results show that the noble gas abundances and isotopic compositions in mantle-derived xenoliths from eastern-central China vary widely:4He abundances from 0.0024×10−6to 25.0×10−6(cm3stp/g);3He/4He ratios range between 0.33RAand 4.62 RA;40Ar/36Ar ratios from 250.56 to 1233.86;40Ar abundances from 0.97×10−6to 34.18×10−6(cm3/g). Only three measured Ne isotopes show a degree of homogeneity:20Ne from 0.3 to 0.7 (cm3stp/g);20Ne/22Ne ratios from 10.5 to 11.0; and20Ne abundances are also rather uniform, from 35.8×10−13to 47.8×10−13(cm3stp/g), and129Xe/130Xe ratios from 6.50 to 6.70. It can be seen that3He/4He ratios vary largely, and40Ar/36Ar ratios are significantly lower than MORB and Proterozoic crust, but close to that of atmospheric values. On the basis of the noble gas abundances and isotope compositions, it can be concluded that Ne, Kr and Xe in mantle-derived xenoliths from NE China have atmospheric origin. The results also show the heterogeneity of noble gases in peridotite from the upper mantle in eastern China, which accords with the results of previous geochemical studies.

Barton Peninsula is mainly composed of Tertiary metavolcanic rocks and granodiorite. The metavolcanic rocks underwent thermal metamorphism up to upper greenschist facies, producing calcic-amphibole (Amp), epidote, chlorite (Chl), calcite (Cc), plagioclase, prehnite and laumontite. Two metamorphic zones, Cc-Chl and Amp-Chl, are defined on the basis of mineral assemblages (+plagioclase, quartz, opaque minerals), characterized by epidote+chlorite±calcite and actinolite±hornblende+epidote+chlorite ±calcite, respectively. The distribution coefficient of Mg−Fe*(total Fe) between actinolite and chlorite, defined by KD=(Mg/Fe*)Act/(Mg/Fe*)Chl, ranges from 0.56 to 1.03, suggesting low-pressure metamorphism. The coexistence of actinolite and oligoclase also supports low-pressure metamorphism. Clorite geothermometry and T−XCO2analysis suggest that metamorphic temperatures reached ca. 300°C at fluid pressures less than 1 kbar. Thermal metamorphism in Barton Peninsula probably was associated with magmatic-arc plutons emplaced during the Tertiary subduction of the southeast Pacific plate under Antarctic Peninsula.

We report Pb-Pb whole rock and uraninite CHemical Th-U-total Pb Isochron MEthod (CHIME) ages of carbonaceous black slates from the Ogcheon metamorphic belt, South Korea. The Pb isotopic data of whole rock samples yield 207 Pb/ 206 Pb ages of 283±33 and 291±13 Ma for two outcrops from the northeastern part of the belt. The uraninite CHIME age is estimated at 283±26 and 281±27 Ma for the northeastern and the middle part of the belt, respectively. All of the above ages are identical within error ranges, and represent the timing of peak metamorphism after the late Precambrian intraplate rifting. On the other hand, the 207 Pb/ 206 Pb whole rock age for the southwestern part of the belt is estimated at 194±27 Ma, probably representing the timing of contact thermal metamorphism associated with the intrusion of Jurassic granitic plutons. Rb-Sr isotopic data of the black slates do not define any meaningful isochron. The early Permian metamorphic age of this study does not support any tectonic scheme in favor of major tectonometamorphism at either the Silurian-Devonian or the Triassic time. Instead, it corroborates the probability that the two zones in the Ogcheon belt, the Ogcheon metamorphic belt and the Taebaegsan zone, were separated from each other before the development of major structural framework in the former. Our data do not support an idea that the Ogcheon belt corresponds to the continuation of the Triassic collision belt in east central China.

In order to elucidate metamorphic conditions of metasedimentary rocks of central Ogcheon metamorphic belt, we investigated the b0parameter and the crystallinity index (CI) of K-white micas from low-grade metapelites. The CI values of muscovite from seventy-eight samples range from 0.08° to 0.19° Δ2θ with an average of 0.12±0.01° Δ2θ, and show no remarkable difference between structurally upper Pibanryeong and lower Poeun lithotectonic units. Slate and phyllite of the Poeun unit have the b0parameters of 8.993–9.031 Å with an average of 9.010±0.007 Å (n=63), whereas those in the vicinity of Poeun granite have slightly lower values of 8.988–9.010 Å with an average of 8.998±0.006 Å (n=33). On the other hand, b0parameters of pelitic schists in the Pibanryeong unit vary from 8.995 Å to 9.042 Å (n=29) with an average of 9.009±0.013 Å that is similar to 9.003±0.009 Å (n=26) in the Poeun unit. These results suggest that low-grade metapelites of central Ogcheon metamorphic belt have experienced a mediumpressure type metamorphism, reaching up to the upper greenschist facies (biotite zone) condition. Moreover, metamorphic pressures estimated from the b0values show no apparent discontinuity across the unit boundary, implying an insignificant vertical displacement along this boundary after the peak metamorphism.

Ages of six volcanic and plutonic rocks on Barton Peninsula, King George Island, were determined using 40Ar/ 39Ar and K-Ar isotopic systems. The 40Ar/39Ar and K-Ar ages of basaltic andesite and diorite range from 48 My to 74 My and systematically decrease toward the upper stratigraphic section. Two specimens of basaltic andesite which occur in the lowermost sequence of the peninsula, however, apparently define two distinct plateau ages of 52-53 My and 119-120 My. The latter is interpreted to represent the primary cooling age of basaltic andesite, whereas the former is interpreted as the thermally-reset age caused by the intrusion of Tertiary granitic pluton. The isochron ages calculated from the isotope correlation diagram corroborate our interpretation based on the apparent plateau ages. It is therefore likely that volcanism was active during the Early Cretaceous on Barton Peninsula. When the K-Ar ages of previous studies are taken into account with our result, the ages of basaltic andesite in the northern part of the Barton Peninsula are significantly older than those in the southern part. Across the north-west-south-east trending Barton fault bounding the two parts, there are significant differences in geochronologic and geologic aspects.

Metasedimentary rocks in the Miwon area of the central Ogcheon metamorphic belt (OMB) are composed of schist, phyllite, slate, quartzite, and marble, together with minor mafic and felsic layers, and are divided into Pibanryeong and Poeun units. Mineral assemblages of the Poeun unit are represented by low-grade assemblages including biotite and chlorite, whereas those of the Pibanryeong unit by kyanite, staurolite, garnet, and biotite. Retrograde minerals include chlorite and white mica. Subsequent to regional metamorphism, thermal flux during the Mesozoic magmatism produced sillimanite, andalusite, cordierite, staurolite, garnet, biotite, and white mica in the contact aureole. Contact metamorphism, however, did not broadly reset mineral compositions of the regional metamorphism. P-T conditions for regional metamorphism of the Pibanryeong unit are in the range of 4.3–8.0 kbar and 510–620°C, which belong to the kyanite stability field. Mineral assemblages and P-T conditions of the Pibanryeong unit in the Miwon area are identical to those reported in the Jeungpyeoung—Deokpyeong area. However, mineral assemblages of the Poeun unit in both areas are not compatible, and suggest a decrease in metamorphic grade towards the southwest along strike of the OMB.

A simulation program (CAPS) calculating the deflection and capacitance change as a function of applied pressure for vm'ious electrode structures and operating conditions has been deveIoped. With its aid, a new method for improving the linearity of a capacitive pressure sensor is proposed. Since the output capacitance of the capacitive pressure sensor is inversely proportional to the gap between the parallel electrodes, the capacitance exhibits non-linearity. The non-linearity is reduced by eliminating the area of large deflection (centre of the diaphragm) from the output capacitance. A prototype device has been designed by using CAPS to reduce the non-linearity and is fabricated using silicon bulk- micromachining technology. The sensitivity degradation and linearity improvement resulting from the use of such an interdigitated electrode structure are 65% and 620%, respectively. By using the interdigitated electrode structure and the simulation program developed in this research, we can optimize the performance of capacitive pressure sensors.

A silicon-based capacitive accelerometer with bulk silicon proof mass, polysilicon rib-style flexures, and detection circuits is fabricated and tested. A complementary metal oxide semiconductor (CMOS) compatible doping and annealing process for 2-µm-thick polysilicon used as a rib-style flexural beam is developed to optimize the trade-off between the mechanical properties and electrical requirements. According to the anisotropic etch simulation and experimental results, we designed a convex corner compensation pattern and fabricated the proof mass. The open-loop gain of the fabricated switched capacitor integrator (SCI) is more than four thousands, and the common mode range is from 0.8 V to 4.5 V. The fabricated accelerometer has sensitivity of 300 mV/g and capacitance change is 0.36 pF/g.