Differences in the relationship between traumatic experiences, self-esteem, negative cognition, and Internet addiction symptoms among North Korean adolescent defectors and South Korean adolescents: A preliminary study

Park, Subin,Lee, Yeeun,Jun, Jin Yong Elsevier/North Holland Biomedical Press 2017 Psychiatry research Vol.257 No.-

<P><B>Abstract</B></P> <P>North Korean adolescent defectors experience adaptation difficulties along with a wide range of psychosocial problems, but no study has yet examined their Internet addiction symptoms. We compared early traumatic experiences, self-esteem, negative cognition, and Internet addiction symptoms, as well as the relationships between these variables, between North Korean adolescent defectors and South Korean adolescents. Fifty-six North Korean adolescent defectors and 112 age- and sex- matched South Korean adolescents participated. The analyses examined the relationship between traumatic experiences and Internet addiction symptoms, with negative automatic thoughts or low self-esteem as mediators of these relations. North Korean adolescent defectors tended to have higher levels of negative automatic thoughts and more severe Internet addiction symptoms, as well as better self-esteem, than did South Korean adolescents. Furthermore, only among North Korean adolescent defectors, traumatic experiences were positively associated with Internet addition symptoms via increasing negative automatic thoughts. North Korean adolescent defectors are more susceptible to Internet addiction, negative cognitions, and early traumatic experiences compared to South Korean adolescents. However, the cross-sectional design of this study precludes consideration of the causality of these relationships. Interventions aiming to correct negative cognitions and increase self-esteem may be helpful for North Korean adolescent defectors with problematic Internet use.</P> <P><B>Highlights</B></P> <P> <UL> <LI> North Korean adolescent defectors had higher trauma and Internet addiction (IA). </LI> <LI> North Korean defectors also had greater self-esteem and negative automatic thoughts. </LI> <LI> Self-esteem and negative thoughts were mediators in the relation of trauma and IA. </LI> <LI> Country of origin (North vs. South Korea) moderated the mediating effects. </LI> </UL> </P>

High temperature design of finned-tube sodium-to-air heat exchanger in a sodium test loop

Lee, H.Y.,Eoh, J.H.,Lee, Y.B. North-Holland Pub. Co 2013 Nuclear engineering and design Vol.265 No.-

A sodium test loop called 'SELFA' (sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger) for simulating thermal hydraulic behavior of the FHX (finned-tube sodium-to-air heat exchanger) unit in a Korean prototype sodium-cooled fast reactor is planned to be constructed at KAERI (Korea Atomic Energy Research Institute). In this study, the elevated temperature design for a model FHX and creep-fatigue damage evaluation have been conducted for the model according to the design codes of ASME section III subsection NH and RCC-MRx based on full 3D finite element analyses. Design optimization for the finned-tubes and tube arrangements in the scaled-down FHX has been performed. The materials of the FHX and piping systems are austenitic stainless steel type 316. The design temperature of the SELFA test loop is 600<SUP>o</SUP>C and the design pressure is 1MPa. The damage evaluation results have shown that no creep-fatigue damage occurs in the present design of the FHX under the intended test conditions.

Synthesis of gold-coated TiO₂ nanorod array and its application as a Raman substrate

Ji, I.A.,Bang, J.H. North-Holland 2013 Materials letters Vol.97 No.-

Gold (Au) nanoparticles were uniformly deposited on hydrophobic TiO<SUB>2</SUB> nanorod arrays through a combination of hydrothermal and photochemical reactions, a process that is difficult to achieve by conventional methods. The Au/TiO<SUB>2</SUB> nanorod array exhibited superior Raman enhancement and was also reusable due to its photocatalytic properties.

Experimental demonstration of surface plasmon resonance enhancement of the tapered optical fiber coated with Au/Ti thin film

Ju, S.,Jeong, S.,Kim, Y.,Jeon, P.,Park, M.S.,Jeong, H.,Boo, S.,Jang, J.H.,Han, W.T. North-Holland 2014 Journal of non-crystalline solids Vol.383 No.-

Dependence of taper angle of the surface plasmon resonance (SPR)-based fiber optic sensor on the SPR absorption and sensitivity was investigated. The SPR wavelength was found to increase from 700nm to 1200nm with the increase of the refractive index of the surrounding oils from 1.404 to 1.434. The SPR sensitivity increased with the increase of metal-coated taper angle (Ω) from 0.07<SUP>o</SUP> to 1.86<SUP>o</SUP> by changing the down/up tapering length or waist diameter. The absorption intensity of the SPR spectrum was found to decrease and the FWHM was broadened with the increase of refractive index of the index matching oils (n=1.404-1.434) due to the leakage of the power fraction of guided rays into the surrounding medium and the spatial spreading and scattering of the conduction electrons, respectively.

Protective relay system for the first demonstration of the HTS cable and the SFCL in live grid in Korea

Lee, S.R.,Yoon, J.,Yang, B.m.,Lee, B. North-Holland 2013 Physica. C, Superconductivity Vol.494 No.-

This study proposed a novel power protection system for the application of 22.9kV HTS cable and SFCL systems to the Icheon substation in South Korea, and studied the protective coordination of the proposed system using a transient simulation program, PSCAD/EMTDC. Korea Electric Power Cooperation (KEPCO) designed and reconstructed the protection system of the Icheon substation based on the results of this study. The 22.9kV, 50MVA HTS cable and 22.9kV, 630A hybrid SFCL systems have been successfully operated in the live power grid of the Icheon substation since August, 2011.

Asymmetry in the neutrino and anti-neutrino reactions in a nuclear medium

Cheoun, M.K.,Choi, K.S.,Kim, K.S.,Saito, K.,Kajino, T.,Tsushima, K.,Maruyama, T. North-Holland Pub. Co 2013 Physics letters: B Vol.723 No.4

We study the effect of the density-dependent axial and vector form factors on the electron-neutrino (ν<SUB>e</SUB>) and anti-neutrino (ν@?<SUB>e</SUB>) reactions for a nucleon in nuclear matter or in <SUP>12</SUP>C. The nucleon form factors in free space are presumed to be modified for a bound nucleon in a nuclear medium. We adopt the density-dependent form factors calculated by the quark-meson coupling (QMC) model, and apply them to the ν<SUB>e</SUB> and ν@?<SUB>e</SUB> induced reactions with the initial energy E=8-80 MeV. We find that the total ν<SUB>e</SUB> cross sections on <SUP>12</SUP>C as well as on a nucleon in nuclear matter are reduced by about 5% at the nuclear saturation density, ρ<SUB>0</SUB>. This reduction is caused by the modification of the nucleon structure in matter. Although the density effect for both cases is relatively small, it is comparable with the effect of Coulomb distortion on the outgoing lepton in the ν-reaction. In contrast, the density effect on the ν@?<SUB>e</SUB> reaction reduces the cross section significantly in both nuclear matter and <SUP>12</SUP>C cases, and the amount maximally becomes of about 35% around ρ<SUB>0</SUB>. Such large asymmetry in the ν<SUB>e</SUB> and ν@?<SUB>e</SUB> cross sections, which seems to be nearly independent of the target, is originated from the differences in the helicities of ν@?<SUB>e</SUB> and ν<SUB>e</SUB>. It is expected that the asymmetry influences the r-process and also the neutrino-process nucleosynthesis in core-collapse supernovae.

Residual stress evolution of polymethylsilsesquioxane thin films with organic templates

Oh, W.,Lee, J.S. North-Holland 2013 Journal of non-crystalline solids Vol.378 No.-

Polymethylsilsesquioxanes (PMSSQs) and star-shaped 4 arm poly(ε-caprolactone)s (PCLs) were homogeneously mixed and chemically linked in their composites. Nanoporous PMSSQ films were made by curing and calcination of the composite films at the elevated temperature. The residual stresses of nanoporous PMSSQ films were analyzed to investigate the reliability of films in the multilayer devices. The residual stresses of PMSSQ/PCL composite films were highly dependent on factors such as the amount of the initial PCL loading and thermal process. The final stresses of nanoporous PMSSQ films ranged from 20 to 50MPa at room temperature, depending on the initial PCL loadings. On heating run, the residual stress of the composite film was attributed to the competition between the relaxation and the curing of matrix polymers. On cooling run, the residual stress of nanoporous PMSSQ film was mainly due to the increased cure density, and the dimension shrinkage of networked matrix polymers.

Matrices uniquely determined by their lonesums

Kim, H.K.,Krotov, D.S.,Lee, J.Y. North Holland [etc.] 2013 Linear algebra and its applications Vol.438 No.7

A matrix is lonesum if it can be uniquely reconstructed from its row and column sums. Brewbaker computed the number of mxn binary lonesum matrices. Kaneko defined the poly-Bernoulli numbers of an integer index, and showed that the number of mxn binary lonesum matrices is equal to the mth poly-Bernoulli number of index -n. In this paper, we are interested in q-ary lonesum matrices. There are two types of lonesumness for q-ary matrices, namely strongly and weakly lonesum. We first study strongly lonesum matrices: We compute the number of mxnq-ary strongly lonesum matrices, and provide a generalization of Kaneko's formulas by deriving the generating function for the number of mxnq-ary strongly lonesum matrices. Next, we study weakly lonesum matrices: We show that the number of forbidden patterns for q-ary weakly lonesum matrices is infinite if q≥5, and construct some forbidden patterns for q=3,4. We also suggest an open problem related to ternary and quaternary weakly lonesum matrices.

Two-loop radiative seesaw model with inert triplet scalar field

Kajiyama, Y.,Okada, H.,Yagyu, K. North Holland 2013 Nuclear physics, B Vol.874 No.1

We propose a radiative seesaw model with an inert triplet scalar field in which Majorana neutrino masses are generated at the two-loop level. There are fermionic or bosonic dark matter candidates in the model. We find that each candidate can satisfy the WMAP data when its mass is taken to be around the half of the mass of the standard model like Higgs boson. We also discuss phenomenology of the inert triplet scalar bosons, especially focusing on the doubly-charged scalar bosons at Large Hadron Collider in parameter regions constrained by the electroweak precision data and WMAP data. We study how we can distinguish our model from the minimal Higgs triplet model.

CO₂ adsorption behavior of microwave synthesized zeolite beta

You, H.S.,Jin, H.,Mo, Y.H.,Park, S.E. North-Holland 2013 Materials letters Vol.108 No.-

Zeolite beta was successfully synthesized by direct synthesis with addition of seeds under microwave irradiation. CO<SUB>2</SUB> adsorption properties on the microwave synthesized zeolite beta were investigated at constant temperature 40<SUP>o</SUP>C and absolute pressure 1atm which compared with zeolite beta synthesized by the conventional hydrothermal method. Microwave synthesized zeolite beta showed higher CO<SUB>2</SUB> adsorption capacity than that of hydrothermal synthesized zeolite beta. Even the surface area of microwave synthesized zeolite beta (463m<SUP>2</SUP>/g) was similar with hydrothermal synthesized one (482m<SUP>2</SUP>/g), higher aluminum contents and the less hydrophilicity of microwave synthesized zeolite beta contributed to the higher adsorption capacity and selectivity of CO<SUB>2</SUB> than those of hydrothermal synthesized one, respectively.