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In this paper, a new approach to reduce the 1/f noise levels in the MOSFETs on varied silicon orientations, such as Si(100) and (110) surfaces, has been carried out. We focus on the Accumulation‐mode (AM) FD‐SOI device structure and demonstrate that the 1/f noise levels in this AM FD‐SOI MOSFETs are obviously reduced on both the Si(100) and (110) surfaces.

How has the high‐latitude solar wind velocity changed over the solar activity cycle? We analyzed interplanetary scintillation data during the years 1985–2001 (excluding the few years around solar maximum) and obtained the following results: (1) the solar wind in the polar region did not change its speed even during the phases of rising and declining solar activity, (2) the N‐S asymmetry of the high‐latitude solar wind speed is a stable structure from 1987 to 1998, (3) the latitudinal velocity gradient at high latitude becomes steeper with increasing solar activity.

Ulysses observed a latitude structure of solar wind in its second fast latitude scan and found that the global structure of solar wind near the solar maximum is significantly different from that in the solar minimum. Also soon after the solar maximum, Ulysses measured that the fast solar wind which has magnetic polarity of the new solar cycle appeared at high latitude in northern hemisphere. This fast wind appeared and disappeared a few times. We introduced a new tomographic algorithm, time‐series tomography, to reconstruct IPS velocity map using all data observed in the year from 1998 to 2001 and analyzed the variation of the solar wind structure through these four year. Especially in 2001, we compared the Ulysses’ fast latitude scan data. As results, it is found that disappearance and recovery of the fast solar wind around the north pole precedes that around the south pole for several months. And also found that the IPS observation shows high level agreement to the Ulysses observation especially for high latitudes.

Using the WIND spacecraft data, we have studied properties of the locally bunched low‐speed stream which was found in association with active regions by tomographic analysis of interplanetary scintillation observations. The source region of this low‐speed stream was inferred to be a small coronal hole at vicinity of active regions by tracing potential magnetic field lines. The following WIND spacecraft observations support this inference of coronal hole origin. (1) Observed magnetic fields have properties of coronal hole origin: IMF polarity is the same as that of the coronal hole, and a magnetic neutral sheet was not observed in the stream. (2) Variations of velocity and density in the stream are as steady and uniform as those in typical high‐speed wind. In addition, we have found that the relative He abundance Nα/NP in this low‐speed stream has 0.032, which is more than two times higher than that in low‐speed wind in the heliospheric plasma sheet (0.013) and very near to that of high‐speed wind from the...

We have developed a Computer Assisted Tomography (CAT) program that modifies a time‐dependent three‐dimensional kinematic heliospheric model to fit interplanetary scintillation (IPS) observations. The tomography program iteratively changes this global model to least‐squares fit IPS data. The short time intervals of the kinematic modeling (∼1 day) force the heliospheric reconstructions to depend on outward solar wind motion to give perspective views of each point in space accessible to the observations, allowing reconstruction of interplanetary Coronal Mass Ejections (CMEs) as well as corotating structures. We show these models as velocity or density Carrington maps and remote views. We have studied several events, including the July 14, 2000 Bastille‐day halo CME. We check our results by comparison with additional remote‐sensing observations, and observations from near‐Earth spacecraft.

We have analyzed the relation between solar wind speeds observed by interplanetary scintillation (IPS) and coronal densities derived from coronagraph observations during the “Whole Sun Month” period in 1996. Since both IPS and coronagraph observations are biased by the effect of line-of-sight integration, tomography techniques are applied to both data sets. For this analysis we made a synoptic map of the solar wind speed at the source surface (2.5 R⊙) from the IPS tomography. Each speed region on the source surface was traced to the height of the coronagraph observations along the magnetic field lines calculated from the source surface potential field model. This analysis has obtained clear anti-correlation between the solar wind speed in interplanetary space and electron density at lower coronal regions. We have also obtained the radial profiles of coronal densities for both slow and fast wind flows in the range of 1.3–2.0 R⊙. We expect that these provide experimental constraints on solar wind accelerati...

Spacecraft observations of the solar wind have been confined to regions near the ecliptic plane until the Ulysses spacecraft has recently made a pass over both solar poles at a heliocentric distance of 2 to 4 AU (1) and encountered continuous fast wind at high latitudes, generally in a range of 700 to 800 km/s (2). On the other hand, there has been no direct measurement at solar distances inside 70 R⊙ where the solar wind is significantly accelerated. The interplanetary scintillation (IPS) method is a unique and useful means to measure global structure of the solar wind in regions near the Sun and at high latitudes where in situ measurements are difficult. Since the IPS measurements, however, are biased by line-of-sight integration effects, a computer assisted tomography method has been developed to deconvolve the line-of-sight integration. We introduce several results from the IPS tomography analysis on latitudinal velocity structure up to 90°, radial distance dependence of fast wind speed, origin of ver...

Simultaneous interplanetary scintillation (IPS) observations at 2 and 8 GHz with the Kashima radio telescope are used to study the radial profile of the solar wind speed near the sun; in the distance range between 10 and 80 solar radii (R⊙). The solar wind speed has been estimated from Kashima IPS data with the co-spectrum method. These speed data are compared with K-corona brightness data taken at 1.36 R⊙ from the Mauna Loa coronameter. The inverse relation between wind speed and K-corona brightness is revealed from this comparison, and better correlation is found for large distances. Derived velocities are sorted by the K-corona brightness to obtain the radial variation unaffected by the latitudinal/longitudinal movement of the line-of-sight. The radial profile of the wind speed from the bright K-corona region shows that the solar wind reaches the terminal speed of about 400 km/s by 20 R⊙, and this terminal speed corresponds to the slow wind. As for the speed profile from the dark K-corona region, the t...