• Journal of The Korean Astronomical Society
• /
• v.29 no.2
• /
• pp.83-91
• /
• 1996

We present a model that rotating primordial blackholes(PBHs) produced at the end of inflation generate the random, non-oriented primordial magnetic field. PBHs are copiously produced as the Universe completes the cosmic phase transition via bubble nucleation and tunneling processes in the extended inflation hypothesis. The PBHs produced acquire angular momentum through the mutual tidal gravitational interaction. For PBHs of mass less than 1013g, one can show that the evaporation (photon) luminosity of PBHs exceeds the Eddington limit. Thus throughout the lifetime of the rotating PBH, radiation flow from the central blackhole along the Kerr-geodesic exerts torque to ambient plasma. In the process similar to the Bierman's battery mechanism electron current reaching up to the horizon scale is induced. For PBHs of Grand Unified Theories extended inflation with the symmetry breaking temperature of $T_{GUT}\;\~\;10^{10}$ GeV, which evaporate near decoupling, we find that they generate random, non-oriented magnetic fields of $\~10^{-11}G$ on the last-scattering surface on (the present comoving) scales of $\~O(10)Mpc$.

• KDI Journal of Economic Policy
• /
• v.38 no.2
• /
• pp.1-20
• /
• 2016

In this paper, we conduct uniform inference of two widely used versions of the Phillips curve, specifically the random-walk Phillips curve and the New-Keynesian Phillips curve (NKPC). For both specifications, we propose a potentially time-varying natural unemployment (NAIRU) to address the uncertainty surrounding the inflation-unemployment trade-off. The inference is conducted through the construction of what is known as the uniform confidence band (UCB). The proposed methodology is then applied to point-ahead inflation forecasting for the Korean economy. This paper finds that the forecasts can benefit from conducting UCB-based inference and that the inference results have important policy implications.

• East Asian Economic Review
• /
• v.22 no.2
• /
• pp.217-239
• /
• 2018

This paper tests empirically the causal relationship between bank loans and the monetary base before and after the adoption of inflation targeting in seven Asia-Pacific countries using Toda-Yamamoto Granger non causality test and the bootstrap test for causality. The most striking finding is that the bank loans Granger cause the monetary base during the inflation targeting period in all the countries, except Japan, which was under the influence of the quantitative easing, whereas the causality appeared diverse before the inflation targeting regime. This result implies the need for the policy makers to take the endogenous nature of the money supply into account in the modern economy.

• Journal of Biosystems Engineering
• /
• v.29 no.4
• /
• pp.301-306
• /
• 2004

Soil stresses were measured beneath the centerline of one new 12.4R28 radial-ply tractor tire. The tire was operated with three inflation pressures(59㎪ 108㎪ and 157㎪) and a dynamic load of 14.2 kN and 20% slip. Soil stress state transducer(SST) measured the stresses in a hardpan soil profile. The depth of the SST was 250mm from soil surface. Analysis of the original soil stress data showed that the inflation pressure of tire did significantly affect the vertical stress. The major principal stresses calculated were more when the inflation pressure was 108㎪ than when it was 157㎪. The peak stresses of the major principal stresses presented more than those of the vertical stresses.

• The Journal of Asian Finance, Economics and Business
• /
• v.2 no.4
• /
• pp.31-38
• /
• 2015

During the last two decades the idea that central bank independence and transparency helps to maintain price stability, became popular among economists and central bankers. Many countries' governments give their monetary authorities higher independence and transparency to achieve the price stability goal. However, emerging countries such as Kazakhstan, suffer from high inflation. This inflation occurs largely due to a low level of independence and transparency of central banks. This research project measures the current level of independence and transparency of central bank of Kazakhstan. Indices were used to measure central bank independence and transparency. Central bank independence was measured by two types of indices: based on central bank laws (legal independence) and based on central banks governor's turnover (TOR). Developing countries have a weak legal framework, implying that a legal independence index cannot be appropriate to use as a measures of actual independence. Therefore, by paying attention to the other two indices, we can say that the central bank of Kazakhstan has a low level of independence and transparency. This, in turn, can be one of the causes of high inflation in Kazakhstan.

• Korean Journal of Remote Sensing
• /
• v.21 no.3
• /
• pp.221-228
• /
• 2005

Baekdusan is a Cenozoic stratovolcano in which a series of micro-seismic events and gaseous emissions have been reported in 1990s. Two-pass DInSAR technique was applied to determine displacement in the volcano by using 10 ERS SAR and 41 JERS-1 SAR datasets. Most interferometric phases out of 58 JERS-1 differential interferograms showed concentric fringe patterns that correlated with elevation. From an analysis of fringe-duration relation, the fringe patterns were found to be severely distorted specifically by stratified troposphere. To estimate the tropospheric delay, we used the data in the Sobaeksan located about 20 km away from the summit of Baekdusan. The maximum and mean magnitudes of the phase delay in the Baekdusan were respectively 13.8 cm and 3.8 cm over 1200 m in altitude. After removing tropospheric effects, a mean inflation rate was estimated to be about 3 mm per year from 1992 to 1998. Although the inflation rate of the volcano is inconclusive without ground truth data, the results indicate that there exists slow upward deformation in the Baekdusan volcano.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.553-556
• /
• 2008

A Magneto Plasma Sail(MPS) produces propulsive force by the interaction between the solar wind and an artificial magnetic field inflated by injecting plasma. Using a 2D hybrid PIC code, we evaluate the inflation of magnetic field when Argon(Ar) plasma with different ${\beta}_{in}$ including the value less than one is injected into the dipolar magnetic field generated by a superconducting coil. It is found that the magnetic field can be inflated by injecting plasma within an angle of $30^{\circ}$ in the polar direction and the magnetic field decays in the polar direction according to $B{\propto}r^{-2.4}$ after the plasma(${\beta}_{in}$=0.1) is injected.

• Publications of The Korean Astronomical Society
• /
• v.3 no.1
• /
• pp.20-29
• /
• 1987

균질(均質) 등방성(等方性) 공간(空間)을 전제하는 Friedmann 우주의 타당성은 Planck 시기($t_p{\sim}10^{-43}sec$) 이진으로 소급시킬 수 없으므로 시초의 비(非)(Non) Friedmann 우주가 가능하다. 본 연구는 우주시초의 특이성과 관련되는 균질 우주와 비균질 우주의 특성, 지평선과 inflation의 관계를 개관한 다음, $t{\sim}t_p$의 양분자(量子論) 요동(搖動)이나 $t>t_p$의 GUT 상전이(相轉移)로 생기는 inflation 계기에 파생(派生)하는 시공(時空)의 거품들이 이루는 비균질(非均質) 우주의 가능성과 인간원리(人問原理)에 기반을 둔 우주 집단의 관련을 고찰한다.

• Journal of the Korean Data and Information Science Society
• /
• v.11 no.1
• /
• pp.73-81
• /
• 2000

The variance inflation factor can be expressed by the square of the ratio of t-statistics associated with slopes of partial regression and partial residual plots. Disagreement of two sides in the interpretation can be occurred, and we analyze it with some illustrations.

• Communications for Statistical Applications and Methods
• /
• v.2 no.2
• /
• pp.303-309
• /
• 1995

Many measures to detect multicollinearity in linear regression have been proposed in statistics and numerical analysis literature. Among them, condition number and variance inflation factor(VIF) are most popular. In this study, we give new interpretations of condition number and VIF in linear regression, using geometry on the explanatory space. In the same line, we derive natural measures of condition number and VIF for logistic regression. These computer intensive measures can be easily extended to evaluate multicollinearity in generalized linear models.