Sedentism, Settlements, and Radiocarbon Dates of Neolithic Korea

There are two conflicting models regarding the role of the Neolithic millet cultivation in the appearance of the Bronze Age farming economy in South Korea. The “continuity model” suggests that the emergence of a farming economy was a consequence of increasing sedentism, and that millet cultivation practiced during the Neolithic played a significant role in the transition to the Bronze Age. On the contrary, the “discontinuity model” suggests that the appearance of the Bronze Age farming economy heavily dependent on rice had little to do with previous millet cultivation in the Neolithic and the degree of sedentism during the latest Neolithic was very low. We test these models by looking into a temporal variation of sedentism, by quantitatively analyzing the quantity of pit houses and settlements based on relative chronology and radiocarbon dates. Sedentary settlements with small-scale millet cultivation appeared in the central-western Korea during the early fourth millennium b.c. They increased sharply during the late fourth millennium b.c. and also appeared in central-eastern and southern Korea, but they almost disappeared in central and southern Korea from the late third millennium b.c., suggesting a return to increased mobility and/or sharp decrease in population. Hence a continuity model for the emergence of a farming economy cannot be accepted. We suggest environmental deterioration as a prime mover for both the appearance of millet cultivation during the fourth millennium b.c. and the disappearance of sedentary settlement from the late third millennium b.c. in Korea

PREDICTION OF RESIDUAL STRENGTH OF COMPOSITE COLUMNS USING FEM ANALYSIS

Fires in buildings cause not only economic losses but also many casualties. A prolonged fire involves the possibility of the damage to structural members, which calls for the repair or reinforcement of the building. Since it is critical to decide whether structural members need reinforcement, the technique to determine the degree of the damage to structural members caused by a fire should be established.  CFT columns are superior to generic steel columns in terms of fire resistance performance thanks to the thermal storage effect of the concrete inside the columns.  Studies have suggested how to reinforce the concrete to further improve the structural strength and fire resistance performance of CFT columns. When CFT columns of a building are damaged by a fire, it is required to determine preciously how serious the structural deterioration of the members is.  The purpose of this study is to evaluate the residual strength of CFT columns damaged by a fire by evaluating the temperature distribution inside the columns and determining the degree of deterioration in the load capacity of concrete and steel in relation to temperature distribution

20 K superconductivity in heavily electron doped surface layer of FeSe bulk crystal

A superconducting transition temperature Tc as high as 100 K was recently discovered in 1 monolayer (1ML) FeSe grown on SrTiO3 (STO). The discovery immediately ignited efforts to identify the mechanism for the dramatically enhanced Tc from its bulk value of 7 K. Currently, there are two main views on the origin of the enhanced Tc; in the first view, the enhancement comes from an interfacial effect while in the other it is from excess electrons with strong correlation strength. The issue is controversial and there are evidences that support each view. Finding the origin of the Tc enhancement could be the key to achieving even higher Tc and to identifying the microscopic mechanism for the superconductivity in iron-based materials. Here, we report the observation of 20 K superconductivity in the electron doped surface layer of FeSe. The electronic state of the surface layer possesses all the key spectroscopic aspects of the 1ML FeSe on STO. Without any interface effect, the surface layer state is found to have a moderate Tc of 20 K with a smaller gap opening of 4 meV. Our results clearly show that excess electrons with strong correlation strength alone cannot induce the maximum Tc, which in turn strongly suggests need for an interfacial effect to reach the enhanced Tc found in 1ML FeSe/STO.Comment: 5 pages, 4 figure

Switchable π-electronic network of bis(α-oligothienyl)-substituted hexaphyrins between helical versus rectangular circuit

The switching phenomena of conformation with π-electronic network through deprotonation-protonation processes were investigated by employing a series of 5, 20-bis(α-oligothienyl) substituted hexaphyrins(1.1.1.1.1.1). They showed significant changes in the absorption and emission spectra with deprotonation, and returned to the initial state with protonation. Through NMR measurements and single crystal X-ray diffraction analysis, we found that the 5, 20-bis(α-oligothienyl) substituted hexaphyrins, which possess acyclic, helical electronic networks involving oligothienyl chains in dumbbell conformations (type-I) in a neutral form, underwent effective deprotonation upon treatment with tetrabutylammonium fluoride (TBAF) to generate the corresponding dianions, which display cyclic electronic networks with enhanced aromaticity in rectangular conformations (type-II). Our quantum calculation results provide an unambiguous description for the switchable conformation and π-conjugation, which revealed that a deprotonation-induced enhanced aromatic conjugation pathway is involved in the switchable π-electronic network

PREVENTING SUBSTANCE ABUSE AMONG ADOLESCENTS: EVALUATION OF AN INTEGRATED MODEL COMBINING LIFE SKILLS TRANING AND PARENT TRANING

This study examines the effectiveness of an integrated model combining Life Skills Training (LST) for students and Love and Logic Training (LLT) for parents. 310 middle school students and 49 parents were participated in the study. A paired sample t-test was computed to compare pre and post-test scores for each participant. An independent sample t-test was used to determine if statistical differences exist between the treatment and control groups. Alcohol use and resistance to alcohol use among both treatment and control groups were significantly changed after the intervention in a positive way. No significant change in substance use was found in both groups. When it comes to comparison between treatment and control groups, a significant difference was found only in resistance to alcohol use, meaning participants in treatment group showed significantly higher level of resistance to alcohol use than control group after the intervention. Implications of these results for practice and training were discussed

Extraction of Prosodic Information from Spoken Word for Synthesizing Korean Speech

This paper describes a study on prosodic information extracted from spoken Korean words, as a preliminary study to synthesize natural Korean speech. We investigated prosodic features-duration, amplitude and pitch-of some 500 words, of which selection was based on appearing frequency in Korean elementary school textbooks. Some results on word-based prosodic information are deduce

Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener

[EN] As buildings are becoming larger, demand for mega-sized composite columns (over 1-meter diameter) is increased. We have developed and commercialized welded built-up CFT column (ACT Column I) since 2005 which are structurally stable and economical using cold-formed steel with rib. However, there has a limit in size of cross section (618 X 618mm) by a fabrication facilities. And due to charateristics of closed cross section, there has a limit to construction of connection of moment frame. Composite mega column (ACT Column II) has same concept of forming closed cross section. But in order to enlarge cross sectional size, thick plate is inserted between cold-formed steels. Since composite mega column can control thickness and width of thick plate, steel or composite beams can be directly attached to the connection. In this study, we propose strength formula of composite mega column to beam connections with T-shaped stiffener as internal diaphragm and verified through finite element analysis and simple tensile experiment.Lee, JH.; Kim, SH.; Kim, BK.; Yom, KS.; Choi, SM. (2018). Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 465-473. https://doi.org/10.4995/ASCCS2018.2018.7016OCS46547