最新版はこちら。 突っ込みは各日付の BBS エントリのほか、 メール (nakano@st.seikei.ac.jp) や フォーム からどうぞ。 なおスパム除けのため、BBS 機能には 緩い認証を入れて います。 検索エンジンから来た方は、エンジンの方のキャッシュを見るか、 下の簡易検索を試してみてください。
|
Namazu for hns による簡易全文検索 詳しくは 詳細指定/ヘルプを参照して下さい |
|||||||||||||||||||||||||||||||||||||||||||||||||
Let us take a moment and ask ourselves: Why, on an Internet that was originally designed to survive a nuclear holocaust, is this DNS thing seemingly so vulnerable?
The reason is pretty obvious: Nearly every other part of the Internet is based on the concept that the individual parts should be able to operate independently. But of all the parts of the Internet, the Domain Name System has a clear heart, a singular point from which all other parts radiate. On most of the net, if one damages a part, the rest of the net will remain and will function. With DNS as it is presently deployed, if one damages the heart, then the rest of DNS becomes uprooted and lost.
Changes: This, the "Pumpkin" release, can sync with NetBSD 1.6, and includes drivers for USB, RAID cards, Gigabit Ethernet, and Token Ring, As a Halloween special, it comes with an ISO image file in addition to a floppy image, so it can be booted from a CD instead of a floppy.
Bulk, single-crystal ZnO was etched in Cl2/Ar and CH4/H2/Ar inductively coupled plasmas as a function of ion impact energy. For CH4/H2/Ar, the etch rate (R) increases with ion energy (E) as predicted from a model of ion enhanced sputtering by a collision?cascade process, R∝(E^0.5-E), where the threshold energy, ETH, is ~96 eV. Band edge photoluminescence intensity decreases with incident ion energy in both chemistries, with a 70% decrease even for low energies (~116 eV). Surface roughness is also a function of ion energy with a minimum at ~250 eV, where Auger electron spectroscopy shows there is no measurable change in near-surface stoichiometry from that of unetched control samples.
Rotated ripple structures (RRS) on sputter-eroded surfaces are potential candidates for nanoscale wire fabrication. We show that the RRS can form when the width of the collision cascade in the longitudinal direction is larger than that in the transverse direction and the incident angle of ion beam is chosen in a specific window. By calculating the structure factor for the RRS, we find that they are more regular and their amplitude is more enhanced compared to the much studied ripple structure forming in the linear regime of sputter erosion.
We simulated a growth model in 1+1 dimensions in which particles are aggregated according to the rules of ballistic deposition with probability p or according to the rules of random deposition with surface relaxation (Family model) with probability 1-p. For any p>0, this system is in the Kardar-Parisi-Zhang (KPZ) universality class, but it presents a slow crossover from the Edwards-Wilkinson class (EW) for small p. From the scaling of the growth velocity, the parameter p is connected to the coefficient of the nonlinear term of the KPZ equation, lambda, giving lambda ~ p^gamma, with gamma = 2.1 +- 0.2. Our numerical results confirm the interface width scaling in the growth regime as W ~ lambda^beta t^beta, and the scaling of the saturation time as tau ~ lambda^(-1) L^z, with the expected exponents beta =1/3 and z=3/2 and strong corrections to scaling for small lambda. This picture is consistent with a crossover time from EW to KPZ growth in the form t_c ~ lambda^(-4) ~ p^(-8), in agreement with scaling theories and renormalization group analysis. Some consequences of the slow crossover in this problem are discussed and may help investigations of more complex models.