• EDISON SW 활용 경진대회 논문집
• /
• 제2회(2013년)
• /
• pp.290-291
• /
• 2013

Ab initio DFT 계산을 통해서 $Si/SiO_2$ 계면의 Band offset을 계산 했다. Si과 $SiO_2$ 각각의 물질을 계산한 결과로 얻은 로컬 퍼텐셜을 기준으로 Valence band와 Conduction band의 band edge의 위치를 결정할 수 있다. 그리고 계면 계산으로 얻은 로컬포텐셜을 이용하여 두물질의 로컬 퍼텐셜의 상대적인 위치를 결정할 수 있고 이를 이용하여 Band offset을 결정 할 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.71-72
• /
• 2010

• 한국정밀공학회지
• /
• 제24권9호
• /
• pp.148-157
• /
• 2007

A new method which uses distance fields scheme and marching cube algorithm is proposed in order to get an accurate offset model of arbitrary shapes composed of triangular net. In the method, the space bounding the triangular net is divided into smaller cells. For the efficient calculation of distance fields, valid cells which will generate a portion of offset model are selected previously by the suggested detection algorithm. These valid cells are divided again into much smaller voxels which assure required accuracy. At each voxel distance fields are created by calculating the minimum distances between corner points of voxels and triangular net. After generating the whole distance fields, the offset surface were constructed by using the conventional marching cube algorithm together with mesh smoothing scheme. The effectiveness and validity of this new offset method was demonstrated by performing numerical experiments for the various types of triangular net.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권3호
• /
• pp.347-353
• /
• 2017

We present a STT-MRAM read-circuit which mitigates the performance degradation caused by offsets from device mismatches. In the circuit, a single current source supplies read-current to both the data and the reference cells sequentially eliminating potential mismatches. Furthermore, an offset-free pre-amplification using a capacitor storing the mismatch information is employed to lessen the effect of the comparator offset. The proposed circuit was implemented using a 130-nm CMOS technology and Monte Carlo simulations of the circuit demonstrate its effectiveness in suppressing the effect of device mismatch.

• The Journal of the Acoustical Society of Korea
• /
• 제23권4E호
• /
• pp.108-111
• /
• 2004

This paper has interest in the effect of a fine frequency offset, defined in ITU-T G.225, to the training performance of an adaptive equalizer. This paper uses Hilbert filter in configuring a transmission system model in order to let it get a frequency offset. Also additive white Gaussian noise and band-limited filter are considered. The signal received from the above transmission system applies to an adaptive equalizer with LMS algorithm, and its training procedures are investigated. As a result, we could find that even small fine frequency offset can severely deteriorate training performance of adaptive algorithm.

• 한국CDE학회논문집
• /
• 제9권2호
• /
• pp.158-163
• /
• 2004

Curve tessellation, which generates a sequence of points from a curve, is very important for curve rendering on a computer screen and for NC machining. For the most case the sequence of discrete points is used rather than a continuous curve. This paper deals with a method of tessellation by calculating the maximal deviation of a curve. The maximal deviation condition is introduced to find the point with the maximal deviation. Our approach has two merits. One is that it guarantees satisfaction of a given tolerance, and the other is that it can be applied in not only a polynomial curve but its offset. Especially the point sequence generated from an original curve can cause over-cutting in NC machining. This problem can be solved by using the point sequence generated from the offset curve. The proposed method can be applied for high-accuracy curve tessellation and NC tool-path generation.

• 한국CDE학회논문집
• /
• 제11권1호
• /
• pp.20-26
• /
• 2006

This paper presents a procedure to compute pencil curves from a triangular mesh which is offset with the radius of a given ball-end mill. An offset triangular mesh has numerous self-intersections caused by an abundance of invalid triangles, which do not contribute to the valid CL-surface. Conceptually, we can obtain valid pencil curves by combining all intersections tying on the outer skin of the offset triangular mesh, i.e., the valid CL-surface. The underlying concept of the proposed algorithm is that visible intersections are always valid for pencil curves, because visible intersections lie on the outer skin of the offset model. To obtain the visibility of intersections efficiently, the proposed algorithm uses a graphics board, which performs hidden surface removal on up to a million polygons per second.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.507-510
• /
• 1998

In this paper, a novel test method is proposed to detect hard and soft fault in CMOS operational amplifiers. Proposed test method mark use of the offset character, which is one of the op-amps characteristics. During the test mode, CUT is implemented to unit gain op-amps with feedback loop. When the input is grounded, a good circuit has a small offset voltage, but a faulty circuit has a large offset voltage exceeding predefined range of tolerance. Using the proposed method, no test vector is required to be applied. Therefore the test vector generation problem is eliminated and the test time is reduced. The accuracy and effectiveness of the method is verified through HSPICE simulation.

• 한국CDE학회논문집
• /
• 제6권1호
• /
• pp.9-16
• /
• 2001

Electrical discharge machining(EDM) is an important process of machining the injection mold. This paper includes efficient design processes of electrodes for EDM. Based on the solid modeler, electrodes can be created by boolean and offset operations with core/cavity models. The built-in offset operations of the solid modeler may occur unexpected results due to the limitations of the solid modeler. We proposed the multi-step and moving-face offset processes in order to apply the EDM clearances. The proposed design processes are implemented with Unigraphics Vl5 API functions and C language and tested on Windows NT 4.0.

• Journal of electromagnetic engineering and science
• /
• 제8권3호
• /
• pp.134-137
• /
• 2008

This paper proposes a novel quadrature VCO(QVCO) based on direct back-gate second harmonic coupling. The QVCO directly couples the current sources of the conventional LC VCOs through the back-gate instead of front-gate to generate quadrature signals. By the second harmonic injection locking, the two LC VCOs can generate quadrature signals without using on-chip transformer, or stability problem that is inherent in the direct front-gate second harmonic coupling. The proposed QVCO is implemented in $0.18{\mu}m$ CMOS technology operating at 2 GHz with 5.0 mA core current consumption from 1.8 V power supply. The measured phase noise of the proposed QVCO is - 63 dBc/Hz at 10 kHz offset, -95 dBc/Hz at 100 kHz offset, and -116 dBc/Hz at 1 MHz offset from the 2 GHz output frequency, respectively. The calculated figure of merit(FOM) is about -174 dBc/Hz at 1 MHz offset. The measured image band rejection is 46 dB which corresponds to the phase error of $0.6^{\circ}$.