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To improve mesophase formation in petroleum-based pitch, the PET (polyethylene terephthalate) additive reaction was studied. PFO (pyrolysis fuel oil) was used to prepare the petroleum pitch, and PET was added at a weight ratio of 0.33–1.50%. The chemical structure of PET-added pitch was analyzed by Fourier transform infrared spectroscopy, and the thermal properties were characterized by thermogravimetric analysis and the softening point method. Added PET provides oxygen during the pitch synthesis reaction, and the polycondensation of the pitch was accelerated by oxygen crosslinking. Thus, the softening point and carbonization value increased with the amount of PET added; moreover, the mesophase content increased by more than three times with 0.33 wt% PET addition. However, at more than 0.67 wt% PET addition, the fluidity rapidly decreased, so the mesophase spheres decreased in size and were independently distributed.

Carbon/carbon composite has superior properties, so it has been expected to use various industrial fields. However, low mechanical strength (than conventional structural materials) works as a hurdle, so the use of oxidative stabilization to improve the mechanical strength of carbon/carbon composites was studied. The oxidation process was performed at 220–350 °C based on thermogravimetric analysis (TGA). The compressive strength of the oxidized sample at 290 °C was 212 MPa, which is 2.5 times greater than that of the non-oxidized sample (84 MPa). However, the oxidation temperature of more than 290 °C decreased the compressive strength (199 MPa at 350 °C). This tendency was in accordance with the TGA and X-ray photoelectron spectroscopy (XPS) results. The effect of oxidative stabilization can be explained by two factors: the polymerization of the used binder pitch by the crosslinking effect by induced oxygen and improvement of the affinity between the coke and binder pitch.

In this study, the effects of activation parameters in the steam activation of polyacrylonitrile-based carbon fibers on pore formation properties were investigated. The activation temperature was used as a primary parameter, and the activation time was adjusted for each condition to obtain similar levels of activation yields. Based on the activation yield of activated carbon fibers (ACFs), the activation energy was calculated as 142.2 kJ/mole. As a result of BET analysis, it was confirmed that the specific surface area and pore volume of ACFs were improved as the activation temperature was increased. The sample treated at 850 during 45 min showed a high specific surface area (1041.9 m2/g) and a pore volume (0.49 cm3/g). This developed pore structures improved the gas adsorption properties of ACFs.

Rotavirus is a leading cause of severe gastroenteritis among children younger than 5 years in South Korea. Two rotavirus vaccines (RVs), pentavalent human-bovine reassortant vaccine (Rotateq®; RV5) and attenuated human strain originated monovalent vaccine (Rotarix®; RV1), have been available for voluntary vaccination using out-of-pocket payment since 2007 and 2008, respectively. Yet, RVs are not included in the National Immunization Program (NIP), partly because of the low associated mortality rate. We assessed the cost-effectiveness of RVs to assist the evidence-based decision-making process for NIP implementation in South Korea. Using a transparent age-structured static cohort model, we simulated the experience of ten annual birth cohorts of South Korean children from 2018 to 2027. Model inputs included rotavirus gastroenteritis (RVGE) incidence and mortality rates, RVGE treatment costs, vaccine coverage and timeliness, and vaccine effectiveness and price. The incremental costs of including RVs in the NIP compared to no vaccination were 59,662,738 USD and 152,444,379 USD for RV1 and RV5, respectively. The introduction of RV1 and RV5 can prevent 4799 disability-adjusted life years (DALYs) and 5068 DALYs. From the societal perspective, the incremental cost-effectiveness ratios (ICERs) for adopting RV into the NIP versus no vaccination were 12,432 USD per DALY averted for RV1 and 30,081 USD per DALY averted for RV 5. The weighted average for the ICERs of the two vaccines computed using the market share of each vaccine in the current voluntary use as a weight, was 21,698 USD per DALY averted. The estimated ICER was below 1 × gross domestic product per capita (30,000 USD), which has been a commonly used willingness-to-pay threshold for health care technology assessment in South Korea, suggesting that introducing RVs into the NIP would be cost-effective.

Dengue virus type 2 NS1 (DENV2 NS1) is a specific and sensitive protein biomarker for dengue fever diagnosis. In this study we used polyvalent phage display to identify unique affinity peptides that can bind NS1 protein. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the binding interactions. The potential affinity peptide-displayed phage from these methods was selected; its sequence was EHDRMHAYYLTR (R3#10). Amino acid sequence analysis showed that the peptide was rich in basic residues (two His and Arg). Among all the peptides tested, R3#10 showed the greatest decrease in current in CV and increase in impedance in EIS upon binding to NS1 proteins. EIS revealed that R3#10 phage clones were more specific towards NS1 proteins, as compared to bovine serum albumin or the M13 wild type used as control. Detection of NS1 proteins is in accordance with the electron-transfer resistance (Rct) value of the sensor layer, which is confirmed by EIS, and the Kd value of the R3#10 peptide while binding to the phage particles was measured. To the best of our knowledge, this is the first example of identification and characterization of NS1 binding affinity peptides using phage display technology and electrochemical methods. We concluded that these new peptide-displayed phages or free peptides from phages may have potential applications in dengue diagnosis.

Three-stage thermal reactions were conducted to investigate empirical trends of petroleum-based pitch production and the chemical characteristics of pitch produced by controlling the temperature and pressure operating parameters. The softening point of pitch increased with increasing reaction temperature under atmospheric pressure, whereas the pitch yield increased with decreasing reaction temperature under a pressurized condition. Elemental analysis supported the result of decreased hydrogen content. In addition, thermogravimetric analysis revealed that higher reaction temperatures could induce the polymerization and condensation of polyaromatic hydrocarbons (PAHs) with carbon yield at 900 °C. The molecular weight distribution (MWD) of pitch was analyzed by MALDI-TOF analysis according to the operating parameters during the thermal reaction. The MALDI-TOF spectrum was normalized to observe the variation in the MWD by Anthracene (178 Da) as a pseudo-component. Range 2–3 and range 6–8 in the MWD coincided with the trends of the pitch yield and the softening point, respectively. The results suggested that pitch yield is related to the PAHs with 2–6 aromatic rings and that the softening point is related to highly condensed PAHs with more than 6 aromatic rings. The anisotropy/isotropy of the pitch was analyzed by polarized light microscopy. The pitch produced under the pressurized condition was isotropic. However, the pitch produced under atmospheric pressure exhibited a well-oriented domain texture. We concluded that volatile contents disturb the polymerization and condensation of PAHs because of side reactions involving the aliphatic contents.

In this study, we developed an electrochemical biosensor coated with a peptide that can detect the protein hemagglutinin (HA) present in the envelope of the influenza virus (H5N1). Using phage display, high-affinity peptide-displaying phage particles (GHPHYNNPSLQL) with specific binding abilities for HA were identified, which were evaluated using enzyme-linked immunosorbent assays (ELISAs). Based on the molecular structure identified by the functional studies, six newly designed peptides were chemically synthesized, and their binding interactions with HA proteins were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), isothermal titration calorimetry (ITC), and surface plasmon resonance spectroscopy (SPR). Square wave voltammetry (SWV) revealed the presence of a linear relationship between the change in current and concentration of HA protein. From these observations, we selected IFA BP1 peptide as a potential molecular receptor and confirmed that the limit of detection (LOD) was found to be 3.26 nM. In addition, our electrochemical sensor successfully detected HA spiked in human plasma samples. Furthermore, good results for reproducibility and recovery using this biosensor were observed within a range of 31.2–500 nM concentrations and 82.3–111.5%, respectively. Importantly, the levels of HA proteins in the samples of human plasma measured using this sensor system corresponded well with those determined using a commercial ELISA method and also offered advantages such as low cost of fabrication, faster analysis, and use of lower sample volumes, suggesting that it could be applied for rapid and effective detection of the influenza virus antigen.

Retinoic acid (RA), a metabolite of vitamin A, has been found to influence regeneration in the adult central nervous system (CNS). There may be an effect of RA in the recovery/repair in multiple sclerosis (MS), an autoimmune and neurodegenerative disease of the CNS. We hypothesized that RA is a regulator of the further differentiation of oligodendrocyte precursor cells (OPCs) – cells key to the remyelination process in MS. We conducted studies utilizing RNA-sequencing in human embryonic stem cell (hESC)-derived neural stem cells (NSCs) and OPCs so as to understand the role of transcriptional regulators during transition from both ESCs to NSCs and NSCs to OPCs. We identified that expression of retinoic acid receptors β and γ (RARβ and RARγ ) was significantly increased following the transition from NSCs to OPCs. We also demonstrated that long term in vitro culture of hESC-derived OPC with different isoforms of RA led to the significant up-regulation of two known transcriptional inhibitors of oligodendrocyte differentiation: Hes5 following prolonged treatment with all-trans-RA, 9-cis RA and 13-cis RA; and Id4 following treatment with 13cisRA. These results suggest that long term exposure to certain RA isoforms may impact the continued differentiation of this population., Highlights • Retinoic acid (ATRA) might have an effect on generation of oligodendrocyte precursor cells (OPC) in the CNS. • RNA-sequencing used for identification of up-regulation of RARβ and RARɣ expression during OPC differentiation. • Activation of RARβ and RARɣ by using three different agonists led increase expression of Hes5 and Id4.

A petroleum residue-based carbon electrode for use in a lithium-ion battery was prepared through the thermal reaction of pyrolyzed fuel oil. The samples were characterized by their softening point, crystallinity and battery performance. The softening point and pitch crystallinity increased with higher reaction temperatures and longer reaction times. The prepared pitch-based carbon had a 300–350 mAh/g capacity and 71–78% initial efficiency. Notably, the high-softening-point pitch resulted in the developed crystallinity through polymerization and condensation. In conclusion, the high-softening-point pitch had a better initial efficiency and rate capability based on its high crystallinity.

In this short communication, vacuum residue, bitumen, and pyrolized fuel oil were analyzed using matrix-assisted laser desorption/ionization – time of flight (MALDI-TOF) analysis to investigate the molecular weight distribution (MWD) variation of heavy oil during visbreaking. The visbreaking of vacuum residue was carried out at 350 °C, 400 °C and 450 °C. Vacuum residue products were studied based on MWD obtained by MALDI-TOF analysis. The separation of MWD was carried out in 8 sections, and each area of the range was calculated. According to our study, the cracking reaction dominated, even though condensation and polymerization were carried out simultaneously. It was noted that the relatively high molecular ranges of 3 and 4 were shifted to the light molecular range of 2. The MWD separation method obtained by MALDI-TOF is a potential analytical tool for investigating the MWD variation of heavy oil.

The petroleum pitch derived from pyrolyzed fuel oil (PFO) was prepared and modified using the solvent extraction method to study the effect of the pitch fraction on electrochemical and structural behaviors. The modified pitches were Hexane-insoluble, Toluene-insoluble and NMP-insoluble pitches. To confirm the structural characteristic parameters such as ( L a , d 002 , I G / I D and true density), X-ray diffraction, Raman spectroscopy and true density measurements were conducted. Electrochemical properties were measured using the coin cell test. Based on the electrochemical properties and structural analyses, the schematic design of the micro-carbon domain was proposed, and the role of each fraction (hexane-soluble, hexane-soluble and toluene-insoluble, Toluene-insoluble and NMPI-insoluble and NMPI fractions) was studied. Each fraction affected the coke during carbonization, and the hexane-soluble fraction and hexane-soluble and toluene-insoluble fraction affected the initial efficiency and Li + ion diffusion resistance.

Inflammasomes are caspase-1-activating molecular platforms that produce active interleukin (IL)-1β and are implicated in various central nervous system (CNS) diseases. These multi-protein complexes can be activated by exposure of cells to low osmolality. The inflammasome nucleotide-binding and oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) is hereby the main sensor of cellular osmolality. IL-1β was found to stimulate the secretion of antidiuretic hormone (ADH) from the posterior pituitary gland either by action of prostaglandins or indirectly by causing the release of IL-6. Based on these findings, we hypothesize that the hyponatremia caused by a wide range of CNS diseases is able to induce significant cell swelling with induction of a hyposmotic intracellular environment, which activates the NLRP3 inflammasome, causing the release of IL-1β and induced by IL-1β, IL-6, which increases the production of ADH that leads to more profound hyponatremia. Supportive evidence for this hypothesis is the finding that IL-1 injection can induce ADH release and hyposmotic effect of ADH induced hyponatremia can, via the mechanical effect of cell swelling, activate transient receptor potential channels, which via transforming growth factor β-activated kinase 1 activate NLRP3. Implications of this hypothesis, if confirmed, would include that hyponatremia can be exacerbated through this vicious cycle but also that the inflammasomes are key mediators of this process. Confirmation of this hypothesis would have implications for prevention and clinical management of changes in patients sodium levels related to syndrome of inappropriate antidiuretic hormone secretion (SIADH) with interventions targeting inflammatory mediator production and function of inflammasomes with the potential of prevention of permanent brain damage in a wide range of CNS diseases.

Pitch synthesis from pyrolyzed fuel oil (PFO) was conducted to understand the empirical synthesis tendency as a function of reaction temperature. Additionally, the chemical and physical characteristics of PFO and produced pitch are identified using X-ray diffraction analysis, thermogravimetric analysis, softening point analysis, and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis. The produced pitch exhibited an enhanced stacking height ( L C ) value and C/H ratio, which is related to the formation of graphitic structure, according to the increased reaction temperature. The carbon residue yield obtained at 900 °C showed a gradually increased value of up to 42.58% in the sample synthesized at the temperature of 410 °C, depending on the increased reaction temperature. The molecular weight distribution of the produced pitches exhibited noticeable variation during the thermal reaction via MALDI-TOF analysis. The variation of the molecular weight fraction is assumed based on the pitch synthesis mechanism, e.g., polymerization, condensation and cracking reaction.

In this work, pitch was synthesized by a thermal reaction of pyrolyzed fuel oil (PFO), and its thermal properties were characterized using thermogravimetric and softening-point analyses. Thin-layer chromatography-flame ionization detection (TLC-FID) was performed to identify the saturated, aromatic, resin, and asphaltene (SARA) fractions to better understand the characteristics of the pitch produced during the high-temperature reaction of PFO. In addition, MALDI-TOF analysis was adapted to confirm the molecular weight segment. During the reaction, the thermal properties of the prepared pitch were determined as a function of the reaction time and temperature. The asphaltene fraction was generated as the aromatic fraction of the material decreased. The pitch properties were observed to be a function of the changes in the molecular weight distribution due to processes such as distillation, condensation, and cracking.

ZnO nanowires on Ga-doped ZnO (GZO) transparent conductive thin films deposited at different substrate temperatures were demonstrated and characterized. The GZO thin films were deposited at various substrate temperatures ranging from 200 to 600 °C in order to study the influence of deposition temperature of the GZO on the characteristics of the ZnO nanowires. The resistivity of the GZO thin films decreased from 5.11×10 −4 (200 °C) to 4.83×10 −4 Ωcm (400 °C) and then increased to 6.12×10 −4 Ωcm (600 °C). The ZnO nanowires were grown vertically and were highly c -axis oriented on the GZO thin films at every deposition temperature without any seed layers. The crystallinity of the ZnO nanowires was improved with increasing deposition temperature of the GZO thin films. In addition, as deposition temperature increased, the diameter of the ZnO nanowires increased, while the density decreased. Photoluminescence (PL) measurement and energy-dispersive X-ray spectroscopy (EDX) proved that the ZnO nanowires on the GZO thin films deposited at higher substrate temperature had less defects and were closer to stoichiometric ZnO. After the growth of the ZnO nanowires on the GZO thin films, the transmittance decreased with respect to that of the GZO only thin films, but the sample was still transparent with an average optical transmittance higher than 70%.

Epitaxial ZnO thin film transistors (TFTs) were successfully fabricated on 4H-SiC (0001) substrates and characterized. When compared with conventional ZnO TFTs on glass substrates that were prepared in the same fabrication process, the ZnO TFTs on 4H-SiC substrates exhibited improved characteristics, namely, a saturation mobility of 5.41 cm2/V s, a threshold voltage of 2.43 V, and a subthreshold swing of 0.61 V/decade. The ZnO TFTs on glass substrates showed 0.44 cm2/V s, −1.55 V, and 1.13 V/decade. Such improved performance is attributed to the different growth behavior and structural properties of the ZnO channel layers on 4H-SiC substrates. Structural analysis on the ZnO channel layers clearly revealed the epitaxial growth of high-crystalline ZnO along the c-axis on 4H-SiC and the polycrystalline growth on glass substrates. The epitaxial ZnO thin films showed a higher Hall mobility of 24.17 cm2/V s due to less grain boundary and a lower carrier concentration of 6.21×1015/cm3 resulting from higher crystalline quality with less defects, whereas the ZnO on glass exhibited 6.24 cm2/V s and 2.37×1017/cm3.

Vertically well-aligned ZnO nanowire arrays were successfully grown on Ga-doped ZnO (GZO) transparent conductive layers. In this study, not only do the GZO thin films play a role as transparent electrodes but also a role as seed layers simultaneously, so that any additional seed layers are not needed. The GZO thin films with various thicknesses (50, 100, and 200 mm) were deposited to investigate the effect of the thickness on the growth behavior of ZnO nanowire arrays. The resistivities of the GZO thin films of 50, 100, and 200 mm thickness were measured to be 8.47×10−4, 7.30×10−4, and 6.51×10−4 Ω cm, respectively. The degree of alignment and the crystalline quality of the ZnO nanowires were improved with increasing the thickness of the GZO thin films. Photoluminescence (PL) measurement, which detected a UV near band edge (NBE) emission peak and a visible deep-level (DL) emission peak on each sample, revealed that the ZnO nanowires were grown with higher crystalline quality and less defects as the thickness of the GZO thin films increased. These may be ascribed to the improved degree of orientation of the (0002) plane and crystallinity of the GZO thin films, which were confirmed by XRD analysis. The grain size of the GZO films, which was observed to increase with increasing the thickness, also influenced the diameter and the density of the ZnO nanowires. With the increase in the grain size of the GZO thin films, the diameter of the ZnO nanowires tended to increase, while the density decreased.

The effect of epitaxial growth on the electrical properties of Ga-doped ZnO (GZO) thin films was studied. GZO thin films were grown on Al 2 O 3 (0001) substrates using pulsed laser deposition (PLD) at various substrate temperatures. Pole figure measurement revealed that the GZO films were grown epitaxially with a 30° in-plane rotation relative to Al 2 O 3 (GZO [ 11 2 ¯ 0 ]||Al 2 O 3 [ 01 1 ¯ 0 ]) to reduce the lattice mismatch. An interesting difference in the variation trend of the resistivity by substrate temperature compared with that of the polycrystalline GZO films, which were prepared for comparison, was observed. The resistivity of the polycrystalline GZO decreased at 200 °C, decreased slightly more at 400 °C, and abruptly increased at 600 °C. However, the resistivity of the epitaxial GZO decreased sharply at up to 400 °C, and decreased continuously at 600 °C. Consequentially, much lower resistivities were obtained at high temperatures of 400 and 600 °C. Considering little difference in the rate of decrease in the carrier concentration between the two kinds of films at each temperature, this different tendency in the resistivity can be explained by the fact that the rate of increase in the Hall mobility of the epitaxial GZO at above 200 °C is much higher than that of the polycrystalline GZO. The higher Hall mobility of the epitaxial GZO is attributed to high crystallinity caused by the epitaxial growth that can induce lower grain boundary scattering. It was proved by using an atomic force microscope (AFM) and a high resolution X-ray diffractometer (HRXRD) that the epitaxial GZO grown at higher temperature showed larger grain size and higher crystallinity, that is, the grain boundary scattering can decrease more, and the Hall mobility can increase enough to compensate for the decrease in the carrier concentration even at high temperature differently from the polycrystalline GZO films.

Kim,Ji Hong.September, 2016.New direction of industrial policy in Korea,Reports,[Sejong, South Korea]KDI School of Public Policy and Management,Working paper/16-10,73

Amorphous InGaZnO (a-IGZO) thin film transistors (TFTs) with double-layer gate dielectric were fabricated at low temperature and characterized. A stacked 150 nm-thick SiO2/50 nm-thick HfO2 dielectric layer was employed to improve the capacitance and leakage characteristics of the gate oxide. The SiO2/HfO2 showed a higher capacitance of 35 nF/cm2 and a lower leakage current density of 4.6 nA/cm2 than 200 nm-thick SiO2. The obtained saturation mobility (μsat), threshold voltage (Vth), and subthreshold swing (S) of the fabricated TFTs were 18.8 cm2 V−1 s−1, 0.88 V, and 0.48 V/decade, respectively. Furthermore, it was found that oxygen pressure during the IGZO channel layer deposition had a great influence on the performance of the TFTs.

Field induced magnetic-anisotropy is a very important but poorly understood property. There have been many hypotheses on the origin of the phenomenon, e.g. strain, atomic pair ordering, etc., but little experimental evidence exist. This study prepares 100 nm thick Permalloy films having the field-induced-magnetic-anisotropy and carefully measure strains, i.e. interplanar distance of crystallographic (111) planes in various directions, using high power synchrotron radiation and precise Grazing Incidence X-Ray Diffraction method. The result delineates that the field-induced-magnetic-anisotropy has a strong correlation with the strain-anisotropy in the film.

Ga-doped ZnO (GZO) thin films were grown on LaAlO 3 (LAO) and SrTiO 3 (STO) substrates by using a pulsed laser deposition (PLD) technique at various substrate temperatures. It was found that the nonpolar a -plane GZO thin films were grown on LAO (1 0 0) substrates. However, the polar c -plane or the c -plane coexistent with the a -plane GZO films were obtained on STO (1 0 0) substrates. The in-plane orientational relationship between the GZO films and substrates was also investigated. The electrical properties of the films were deeply affected by the growth orientation. The GZO films with a -axis oriented phase showed higher resistivity than with c -oriented phase, which can be ascribed to the lower mobility due to the increase in grain boundary scattering.

It was studied that FePt-Ta thin films prepared on MgO (100) buffer-layer by DC/RF magnetron co-sputtering have shown better magnetic properties and micro structural improvement. The Ta-doped FePt-Ta films indicate somewhat differences in micro structural ordering and the aspect of grain growth after annealing. With respect to magnetic property, the sample having 30% increased coercivity was obtained after a heat treatment at 700^oC. In particular the addition of Ta (5.5%) enhances the L1"0 ordering of FePt at relatively high temperature (above 500^oC).

Epitaxially grown ZnO thin films on 4H–SiC (0 0 0 1) substrates were prepared by using a pulsed laser deposition (PLD) technique at various substrate temperatures from room temperature to 600 °C. The crystallinity, in-plane relationship, surface morphology and optical properties of the ZnO films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and photoluminescence (PL) measurements, respectively. XRD analysis showed that highly c -axis oriented ZnO films were grown epitaxially on 4H–SiC (0 0 0 1) with no lattice rotation at all substrate temperatures, unlike on other hexagonal-structured substrates, due to the very small lattice mismatch between ZnO and 4H–SiC of ∼5.49%. Further characterization showed that the substrate temperature has a great influence on the properties of the ZnO films on 4H–SiC substrates. The crystalline quality of the films was improved, and surfaces became denser and smoother as the substrate temperature increased. The temperature-dependent PL measurements revealed the strong near-band-edge (NBE) ultraviolet (UV) emission and the weak deep-level (DL) blue-green band emission at a substrate temperature of 400 °C.

We report orientation-controllable growth of ZnO thin films and their orientation-dependent electrical characteristics. ZnO thin films were deposited on single-crystalline (1 0 0) LaAlO3 and (1 0 0) SrTiO3 substrates using pulsed laser deposition (PLD) at different substrate temperatures (400–800 °C). It was found that the orientation of ZnO films could be controlled by using different substrates of single-crystalline (1 0 0) LaAlO3 and (1 0 0) SrTiO3. The a-plane ( 1 1 2 ¯ 0 ) and c-plane (0 0 0 2) oriented ZnO films are formed on LaAlO3 and SrTiO3, respectively. In both cases, the degree orientation increased with increasing deposition temperature Ts. Both the surface free energy and the degree of lattice mismatch are ascribed to play an important role for the orientation-controllable growth. Further characterization show that the grain size of the films with both orientations increases for a substrate temperature increase (i.e. from Ts = 400 °C to Ts = 800 °C), whereas the electrical properties of ZnO thin films depend upon their crystalline orientation, showing lower electrical resistivity values for a-plane oriented ZnO films.

This paper studies the economic assimilation of North Korean refugees settled in the South. Do the North Korean refugees get assimilated into the labor market in the South at all? If yes, how fast is the assimilation? More specifically, what is the initial wage gap at the entry between refugees and native workers with identical observable characteristics? How does the gap change as time passes? For the purpose, we analyze the unique survey data set constructed for this study. The cross section survey has detailed retrospective information not just on labor market activities of the refugees, but also on their economic life while still in the North. The survey covers about 700 adult refugees. For the comparison of the refugee workers with the natives, the survey data set are combined with the 2002 wave of the Korea Labor Institute Panel Study (KLIPS). In comparison to the assimilation of immigrant workers in the US, initial wage gap seems much larger for the North Korean refugee workers, but also closes at a higher rate than is the case in the US. The disconcerting finding is that the gap in employment probabilities is also large in the Korean context, and takes a long time to close, especially for female refugee workers.

Korean society had adopted the draft system for several decades, and more careful analysis of military personnel procurement system is needed. The pros and cons of draft and recruit system is compared, and the third chapter explains an economic model. A model to analyze various issues are presented and discusses the implication is discussed.

Kim, JiHong.2006.Korea-US FTA,Report,SeoulKDI School of Public Policy and Management,KDI School Working Paper Series/06-17,26

This paper intends to provide a framework on the optimal policy of developing economy in response to speculative attacks. It is also related with the issue of pegging vs flexible exchange rate system and the optimal commitment to a fixed rate. I borrow the model by Lahiri and Vegh(2001), and extended it in order to provide general guidelines useful for the case of currency crisis. The model in this paper incorporates three key frictions: an output cost of nominal exchange rate fluctuations, an output cost of higher interest rates to defend the currency, and a fixed cost of intervention. The optimal policy response of developing economy faced with currency crisis can be influenced by three contexts; size of shock, source of shock, economic fundamentals. 1. If small shock, no intervention by depreciating the currency depreciate is desirable. If large shock, the output costs is too large compared to the intervention cost, and it is optimal to stabilize the exchange rate with Intervention. 2. If Monetary Shock, fixed FX system works better for insulating the real side of the economy from monetary shock. If Real Shock, flexible FX system works better because real shock changes the real wages. 3. If Weak fundamentals, the output costs are unbearable and no intervention is desirable. If Strong fundamentals, the output costs are endurable and intervention to stabilize the exchange rate is desirable.

Kim, Ji Hong.December, 2004.Speculative attack and Korean exchange rate regime,Report,[Seoul]KDI school of Public Policy and Management,Working papers,21

To the Editor: We read with interest the article by Pillebout et al. They reported that the addition of cyclophosphamide to steroids provided no benefit compared with steroids alone in adults with Henoch Schonlein purpura (HSP) nephritis. In this study, however, they did not mention an important randomized controlled study of cyclophosphamide in children with severe HSP nephritis, showing there were no differences in outcome between the two groups (supportive therapy with or without oral cyclophosphamide 90mg/m per day for 42 days). We speculate that cyclophosphamide might provide no benefit in the patients studied by Pillebout et al. on the basis of the drug-related characteristics of decreasing fibrinolytic activity. Although not extensively studied yet, we previously reported that fibrinogen deposition is closely related to the formation of crescents and severe renal injury in HSP nephritis and Bazzan et al. demonstrated that a significant decrease in plasma fibrinolytic activity was observed after cyclophosphamide therapy. Therefore, there is a possibility that fibrinogen deposition by decreased fibrinolytic activity after cyclophosphamide use might influence the renal outcome in HSP nephritis. Furthermore, cyclophosphamide was administered in combination with urokinase (fibrinolytic agent) to severe HSP nephritis patients; it resulted in not only more reduction of proteinuria but also lower activity and chronicity index at follow-up renal biopsies than in those who were not treated with cyclophosphamide. Therefore, it would be interesting if fibrinogen deposition and crescent formation are evaluated before and after cyclophosphamide therapy, although it was not carried out in the patients studied by Pillebout et al. Further studies should be performed to elucidate the effects of cyclophosphamide on intraglomerular coagulation in patients with HSP nephritis.