Housing policy, mortgage markets, and housing outcomes in Korea

노트 : A publication of the Korea Economic Institute and the Korea Institute for International Economic Polic

Contests with Bilateral Delegation: Unobservable Contracts

We study two-player contests in which, in order to win a prize, each player hires a delegate to expend effort on her behalf; neither party's delegation contract is revealed to the rival party when the delegates choose their effort levels. We obtain first the outcomes of this unobservable-contracts case. Next, we perform comparative statics of these outcomes with respect to the higher-valuation player's valuation for the prize. Finally, we compare the outcomes of the unobservable-contracts case with those of the observable-contracts case. We find, among other things, that the unobservability of delegation contracts narrows the gap between the delegates' equilibrium contingent compensation

Contests with Bilateral Delegation: Unobservable Contracts

We study two-player contests in which, in order to win a prize, each player hires a delegate to expend effort on her behalf; neither party's delegation contract is revealed to the rival party when the delegates choose their effort levels. We obtain first the outcomes of this unobservable-contracts case. Next, we perform comparative statics of these outcomes with respect to the higher-valuation player's valuation for the prize. Finally, we compare the outcomes of the unobservable-contracts case with those of the observable-contracts case. We find, among other things, that the unobservability of delegation contracts narrows the gap between the delegates' equilibrium contingent compensation

In vitro antioxidative activity of moss extract, and effect of moss on serum lipid level of mice fed with high-fat diet

Purpose: To evaluate the potential of active compounds derived from moss in the prevention and treatment of various diseases.Methods: Three species of moss were extracted with deionized water at 95 °C, and with 70.5 % ethanol at 85 °C. Analysis of total phenolic contents (TPC) of the extracts were performed by Folin- Ciocalteu (FC) method. The antioxidant activity of the extracts were determined using three methods, namely, by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). In vivo effects were evaluated in mice fed high fat diet (HFD) supplemented with 20 % ground moss. Cholesterol levels in HFD were evaluated by ophthalaldehyde method. Serum triglyceride levels were measured using triglyceride (TG) kit, while blood insulin level and leptin concentration were measured by enzyme-linked immunosorbent assay (ELISA) kit.Results: The moss extracts exhibited antioxidative effects, as evidenced of . TPC of 47.20 ± 11.20 to 119.87 ± 11.51 mg GAE/mg, respectively. ABTS scavenging activity was 1078.11 ± 18.95 to 2587.33 ± 46.19 μmol Trolox/mg, DPPH scavenging activity of were 42.11 ± 8.22 to 298.78 ± 20.02 μmol Trolox/mg, and FRAP value of 393.19 ± 24.64 to 1070.14 ± 17.92 μmol Trolox/mg, respectively. Mice fed with 20 % ground moss did not show any significant effect (p < 0.05) on visceral weight and blood lipid levels of HFD, while leptin concentrations reduced significantly to 4.74 ± 0.00 and 0.20 ± 0.00 ng/dL) relative to HFD alone (26.72 ± 6.53 ng/dL).Conclusion: Moss can potentially be used as an antioxidative ingredient, for the improvement of overall human health, suggesting that important medical benefits associated with moss consumption. However, further investigations are required to ascertain this.Keywords: Moss, total phenolic content, antioxidant activity, insulin, lepti

Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin Torque

The current-induced resonant excitation of a magnetic vortex core is investigated by means of analytical and micromagnetic calculations. We find that the radius and the phase shift of the resonant motion are not correctly described by the analytical equations because of the dynamic distortion of a vortex core. In contrast, the initial tilting angle of a vortex core is free from the distortion and determined by the nonadiabaticity of the spin torque. It is insensitive to experimentally uncontrollable current-induced in-plane Oersted field. We propose that a time-resolved imaging of the very initial trajectory of a core is essential to experimentally estimate the nonadiabaticity.Comment: 4 pages, 4 figure

Ceramic Processing Research The preparation of indium tin oxide films as a function of oxygen gas flow rate by a facing target sputtering system

Indium tin oxide (ITO) thin films for use as cathode electrodes in top-emitting organic light-emitting diodes (TOLEDs) were prepared by a facing targets sputtering (FTS) system under different sputtering conditions, which were varying oxygen gas flow rate, input current at room temperature on glass slide substrates. Then a function of sputtering conditions, the electrical and optical properties of prepared ITO thin films was evaluated. In the results, with increasing oxygen gas flow rate 0.1 sccm to 0.7 sccm, resistivities of ITO thin films increased with a decrease in carrier concentration, with an oxygen gas flow rate above 0.3 sccm. Transmittance of prepared ITO thin films was improved at increasing oxygen gas flow rate 0.1 sccm to 0.7 sccm. And transmittance of all of the prepared ITO thin films was over 80%. We could obtain resistivity 6.19×1

Vulnerability assessment for the hazards of crosswinds when vehicles cross a bridge deck

AbstractA new procedure to assess the crosswind hazard of operating a vehicle over a bridge deck has been developed using a probabilistic approach that utilizes long-term wind data at bridge sites as well as the aerodynamic properties of bridge decks and vehicles. The proposed procedure for safety assessment considers the probabilities of two accident types: sideslip and overturning. The vulnerability of vehicles to crosswinds is represented by the number of days for traffic control that would be required to secure vehicle safety over a period of one year. The distribution of wind speed over a bridge deck was estimated from a section model wind tunnel test. A sea-crossing bridge was selected as an example, and a series of case studies were performed to identify the influential factors affecting vehicle vulnerability to crosswinds: vehicle type and loaded weight, the position of a running vehicle over a bridge deck, the bridge alignment relative to the dominant wind direction, and vehicle speed

Attitude after a mild aortic valve lesion during rheumatic mitral valve surgery

ObjectiveWe evaluated whether rheumatic aortic valve disease of mild degree should be treated in patients undergoing mitral valve surgery.MethodsFrom 1992 to 2010, 197 patients (aged 52 [19-82] years, male:female = 60:137) who had rheumatic mitral valve disease and mild aortic valve disease were enrolled. The aortic valve was untreated in 114 patients (no treatment group), repaired in 40 patients (aortic valvuloplasty group), and replaced in 43 patients (aortic valve replacement group).ResultsOperative mortality occurred in 4 patients (2.0%). There were no differences in early mortality and postoperative complications among the 3 groups. Overall survival at 5, 10, and 15 years was 96.3%, 92.1%, and 85.7%, respectively. In the no treatment group, progression-free survival in significant aortic valve disease at 5, 10, and 15 years was 98.7%, 91.3%, and 81.1%, respectively. This was not superior in the aortic valvuloplasty group (85.9%, 77.6%, and 69.8%, respectively) than in the no treatment group. Freedom from aortic valve disease was lower in patients with aortic stenosis than in those with aortic regurgitation in univariate and multivariable analyses (P < .001). Reoperation was performed in 19 patients, including 2 aortic valve reoperations. Aortic valve–related event-free survival was similar among the 3 groups.ConclusionsMild aortic valve disease in patients undergoing rheumatic mitral valve surgery could be left untreated, because preventive aortic valve operation does not result in better clinical and echocardiographic outcomes