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Despite the symbolism of TiO2 in photoelectrochemistry, its fundamental nanoscale properties in oxidation reaction have often reported inconsistent results. We demonstrated the simple model of TiO2 thin films (TFs) for photoelectrochemical (PEC) oxidation reaction (OR) of water, which is constituted of Indium Tin Oxide (ITO) and TiO2 TFs, by depositing it directly onto ITO coated glass substrates through Atomic Layer Deposition (ALD). Using ALD with a sub-nanometer thickness control, 9 to 90 nm in thickness (200 to 2000 in no. of ALD cycles) of TiO2 TFs were fabricated and annealed for crystallization into anatase phase. Anatase TiO2 TF photoanodes showed an optimum PEC OR performance at the thickness of 45 nm (corresponding to around 1000 ALD cycles) in the electrolyte solution of 0.1 M NaOH (pH = 12.9) under UV light illumination of 365 nm in wavelength. Different thicknesses of TiO2 TFs were characterized by electrochemical and optical measurements. Increasing bulk traps in TiO2 TFs up to the critical thickness improved charge transfer and PEC OR by increasing holes’ lifetime. However, it was found to be detrimental when it became dominant along with the increase of TFs’ thickness. This work provides insight in designing highly efficient TiO2 photoelectrodes with the precisely controlled thickness that can have a significant effect on charge transfer kinetics and thus PEC performances.

Molybdenum disulfide (MoS2) is rapidly emerging in a wide range of applications owing to its superior optical, electrical, and catalytic properties. In particular, aside from the current great interest in monolayer MoS2, MoS2 quantum dots (QDs) have received much attention in the electronics and optoelectronics fields owing to their inherent electrical and optical properties arising from the quantum confinement effect. Thus, various methods for producing MoS2 QDs, such as exfoliation, substrate growth, and colloidal synthesis, have been attempted. In this study, the method for manufacturing MoS2 QD with a size of 10 nm which is simpler than the conventional method was devised. On the basis of characterization of the prepared MoS2 QD samples, resistive switching devices was fabricated. These devices demonstrated stable unipolar resistive switching behavior without an electroforming process. This study provides a new approach for the mass production of MoS2 QD and one of their potential applications.

The effects of surface finishes on the in situ interfacial reaction characteristics of ball grid array (BGA) Sn-3.0Ag-0.5Cu lead-free solder bumps were investigated under annealing and electromigration (EM) test conditions of 130°C to 175°C with 5.0 × 103 A/cm2. During reflow and annealing, (Cu,Ni)6Sn5 intermetallic compound (IMC) formed at the interface of electroless nickel immersion gold (ENIG) finish. In the case of both immersion Sn and organic solderability preservative (OSP) finishes, Cu6Sn5 and Cu3Sn IMCs formed. Overall, the IMC growth velocity of ENIG was much lower than that of the other finishes. The activation energies of total IMCs were found to be 0.52 eV for ENIG, 0.78 eV for immersion Sn, and 0.72 eV for OSP. The ENIG finish appeared to present an effective diffusion barrier between the Cu substrate and the solder, which leads to better EM reliability in comparison with Cu-based pad systems. The failure mechanisms were explored in detail via in situ EM tests.

The casino industry for foreign visitors has been used as a tool of economic development in Korea. The objective of the current study was to examine cultural elements of the interaction between casino workers and guests at Korea's largest casino, the Walker Hill Casino located in Seoul. The guests were grouped into five major cultural groups: Japanese, Korean residents abroad, Chinese (Mainland Chinese, Taiwanese, Hong Kong Chinese), Westerners (US citizens and Europeans), and others (mainly Sri Lankan, Philippine, Bangladeshi, Thai and Malaysian). Based on casino employees’ perceptions significant differences were observed on all 28 items of behaviours of casino customers from the five cultural groupings. As a result, it is apparent that cultural differences will have a range of implications for management including marketing, training of staff and service provision for guests.

An electronic book (eBook) has quite a few advantages over a paper-based book. However, several technical problems have not been solved until now in spite of the growing interest in eBooks, eBook industries are using different document formats with the result of difficulty in exchanging and sharing eBook contents and reinvestment in developing the related software. The US and Japan have realized the importance of a standard document format for eBooks, so they have developed the Open eBook Publication Structure (OEB PS) and JepaX, respectively, with the support from government agencies and related industries. Recently, the Electronic Book of Korea (EBK) has established a working group and developed a standard format based on the eXtensible Markup Language (XML) for eBooks. The goals of the standard include the explicit exchange of eBook contents reflecting the characteristics of the Korean publishing environment, simplicity in creation and exchangeability with the related formats. The standard supports the logical structure of various document classes as well as advanced style control such as vertical writing and multi-column editing based on XSL.