[en] Recently, there occur many damages and disasters due to mistakes in designing, and the author has attempted measures for effective prevention of damages. For this purpose, the author collected the theses on accidents due to poor designs and their measures. Many accidents are blamed for their poor designs as their causes. The way to prevent mistakes in designing is to keep in file the cases of such accidents for a system to be ready for use whenever needed. (Author)

[en] Single-photon detection and photon counting are useful tools in many fields, from light detection and ranging (LiDAR) to biomedical imaging and from time-resolved Raman spectroscopy to quantum applications. In this context, recently, single-photon avalanche diode (SPAD) sensors in standard CMOS technology have been receiving considerable attention from both scientific and industrial communities since they can provide single-photon detection and photon-counting capabilities along with some functionalities such as time-of-arrival evaluation and histogram processing in a cost-effective manner. In this review, we provide a comprehensive view of the CMOS SPAD technology: from fundamentals to cutting-edge technologies including three-dimensional (3D)-stacked CMOS SPAD sensors. (author)

[en] Six physical properties (enthalpy, density, decomposition temperature, solubility in water, pKa values, and hydronium potential) were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index, and Ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content, and polarizability. This paper examines the correlation of the molecular modeling techniques parameters and the physicochemical properties of amino acids. As a results, calculated values were in agreement with experimental data in the above six physical properties of amino acids and the molecular connectivity index was superior to the other indices in fitting the calculated data

[en] The sandwich sign is used to describe mesenteric lymphoma in which mesenteric vessels and fat are enveloped by enlarged mesenteric lymph nodes. We present two cases of primary pleural lymphoma demonstrating the 'pleural sandwich sign'. Contrast-enhanced computed tomography showed conglomerated parietal pleural and extrapleural masses encasing the intercostal arteries. Histopathological examinations confirmed low grade marginal zone B-cell lymphoma in an 80-year-old man and diffuse large B-cell lymphoma in a 68-year-old man. The pleural sandwich sign may suggest the diagnosis of primary pleural lymphoma.

[en] The residual stress is the key factor causing the reliability problem of thermal barrier coating (TBC). The failure of plasma spray coatings due to residual stresses is a serious and recurring problem of TBC. The difference of thermal expansion coefficient between the substrate and each coating combined with temperature evolution and temperature gradients during deposition process determine the residual stress for the whole TBC system. The magnitudes and distributions of the residual stresses are affected by deposition process and deposition characteristics. Most of FEA (finite element analysis) has been performed under the assumption that the multilayer coating system is stacked at once without considering the deposition process during plasma spraying. In this research, FEA for a coupled heat transfer and elastic-plastic thermal stress was performed to obtain the more detailed and reliable result of residual stress of the TBC system using the element activation/deactivation technique. The residual stress variation from the start of plasma spraying to cooling stage with room temperature was obtained systematically considering the deposition process. It can be used as reference data to improve the performance of TBC. In addition, the relationship between residual stress and coating conditions such as cooling rate and time is also examined thoroughly.

[en] To investigate the impact of the proposed International Association for the Study of Lung Cancer (IASLC) tumor, node, metastasis (TNM) system on staging and outcome of non small cell lung cancer (NSCLC). With a total of 501 NSCLC patients with staging according to Union for International Cancer Control (UICC), 6th TNM (TNM-6) were reclassified according to the IASLC proposed TNM staging (TNM-7). The impact of TNM-7 in comparison with TNM-6 was evaluated at three levels: change in substage, staging, and outcome. The outcome measure was to compare the stage-specific overall survival of NSCLC between the two groups of patients. A total of 214 (42.7%) patients had changed TNM staging, and 101 (20.2%) patients had changed stage groupings in TNM-7 compared to TNM-6. Among 100 patients showing changed stage grouping, 72 (14.4%) showed upstage and 29 (5.8%) demonstrated downstage. The TNM-7 system resulted in better separation of survival curves among stage-specific NSCLC than TNM-6 system, especially in separation of stage IIA vs. IIB (p 0.023) and stage IIIB vs. IV (p < 0.001). TNM-7 for lung cancer appears to be superior in defining stage-specific survival groups than TNM-6, especially between stage IIA vs. stage IIB and stage IIIB vs. stage IV.

[en] A Dense Plasma Focus (DPF) device is studied as a radiation sources such as X-ray, proton, electron and neutron, as the most powerful laboratory neutron source. DPFdevice is investigated as a neutron source with pure deuterium gas in the electric Probe Applications Laboratory (ePAL) of Hanyang University. This device is composed of a capacitor bank (32μF), a spark gap switch, and two electrodes along with electrical circuits. Charging voltage is 16kV and the typical discharge peak current is about 183kA. The generated neutrons with different deuterium filling pressure are measured with the different electrode lengths by means of the bubble neutron dosimeter (BDPND: Bubble Technology Industry). The maximum neutron yield is estimated about 6.4x10⁸ n/shot with pressure of ∼3 Torr

[en] A micro/nano pattern was simply fabricated on the surface of a hydroxyethyl cellulose (HEC) thin film and its properties were investigated. HEC is easily dissolved in water and has excellent properties such as viscosity, transparency and stability. In this study, HEC was prepared by chemical processing with water-insoluble cellulose and water-soluble ether and was then cast as a flexible film. With the use of a micro patterned metal mold, the pattern was simply replicated on the solid-state HEC film. Micro/nano hybrid structured patterns consisting of micro-scale structures of about 10 μm and nano-scale fibrils of less than 10 nm were prepared, and the surface characteristics of the patterned HEC film were experimentally verified. Measurements showed that the micro/nano hybrid structure resulted in a higher water drop contact angle, but the contact angle decreased gradually with increasing wetting time.

[en] A new unmagnetized collisional Mach probe theory is developed in order to resolve the collisional effect on Mach probe analysis by including ionization, charge and momentum transfer of ions in the perturbation region of a Mach probe. A fluid model is established by assuming Boltzmann electrons and taking the moments of the one-dimensional Boltzmann transport equation, which contains the two-dimensional transport information as a source, after adding a collisional term. A new relation between the flow velocity and the ratio of the ion sheath current densities is obtained, and is compared with those by a collisionless kinetic theory and a particle-in-cell simulation in the applicable range of these theories. A new relation between flow velocity and the ratio of the ion sheath current densities shows that ion-neutral collisions have a very strong effect to produce much smaller Mach numbers from the same ratio than those by collisionless models.

[en] An efficient photo-annealing approach for high-performance solution-processed metal-oxide thin film transistors (TFTs) was demonstrated by using programmable pulse operation of xenon flash lamp. The flash lamp annealing (FLA) process could offer not only low-temperature (≈100° C) processing but also ultra-fast annealing speed of the order of seconds under air ambient conditions. Solution-processed amorphous indium-gallium-zinc-oxide (α-IGZO) TFTs implemented by the FLA process typically exhibited much improved electrical performance such as saturation mobility of >10.8 cm²V⁻¹¹s⁻¹, ION/IOPP of >10⁸, and subthreshold slope of as steep as 0.24 V/dec. X-ray photoelectron spectroscopy analysis of a-IGZO films indicates that the FLA can provide sufficient activation energy for rapid formation of solid a-IGZO bonds within 30 s. The high-quality metal-oxide films achieved by an atmospheric and low temperature FLA method may represent a significant advance for scalable fabrication of flexible and printed metal-oxide electronics.