• 전자공학회논문지A
• /
• 제33A권2호
• /
• pp.184-195
• /
• 1996

Beause BiCMOS logic circuits consist of CMOS part which constructs logic function and bipolar part which drives output load, the effect of short faults on BiCMOS logic circuits represented different types from that on CMOS. This paper proposes new test method which detects short faults on BiCMOS logic circuits using current path graph. Proposed method transforms BiCMOS circuits into raph constructed by nodes and edges using extended switch-level model and separates the transformed graph into pull-up part and pull-down part. Also, proposed method eliminates edge or add new edge, according ot short faults on terminals of transistor, and can detect short faults using current path graph that generated from on- or off-relations of transistor by input patterns. Properness of proposed method is verified by comparing it with results of spice simulation.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.810-813
• /
• 2000

Burr makes trobles on manufacturing process due to deburring cost, quality of products and productivity. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. The cutting parameters were investigated changing exit angle, rake nagle , lead angle in tool geometry as well as feed per tooth. Also we carried out experimets on several materials. Using the result of experimental study, burr types are classified according to appearance and formation mechanism in exit burr and we are considered the burr formation in each type of burr.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.911-914
• /
• 1997

This Experiment was carried out for bur minimization in drilling. New drill geometries are proposed to minimize the burr formation in drilling operation. Three types of drills are made, champer, round and step drill. The burr formed in first cutting by front cutting edge ca be removed in second cutting by the cutting edges in chamfer, round edge and step. New burrs are formed by second cutting and can be minimized according to the change of drill geometry like, chamfer size and angle, corner radius in round drill and step size and angle in step drill. To measure the burr formed in drilling, laser sensor is used.

• 한국공작기계학회논문집
• /
• 제16권5호
• /
• pp.48-54
• /
• 2007

Surface of rapid prototype has inevitably stair-stepping error, which is attributed to the continuous building process of 2 dimensional area. In this study, rounded edge model was established to estimate the roughness of inclined surface which has stair-stepping error. To investigate the roughness of rapid prototypes, specimens that have various surface inclinations were manufactured by various types of RP machines. As the surface inclination increased, the roughness of the specimens manufactured by SL, FDM, or LOM process decreased, which coincides with the simulation results. However, surface roughness of 3DP specimen was almost independent of the inclination. Furthermore, as the angle of surface increased, roughness of poly-jet specimen also increased, which is attributed to the frictional behavior between writing head and scanned area.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권4호
• /
• pp.611-617
• /
• 2004

Pixel classification is one of basic image processing issues. The general characteristics of the pixels belonging to various classes are discussed and the radical principles of pixel classification are given. At the same time. a pixel classification scheme based on image direction measure is proposed. As a typical application instance of pixel classification, an adaptive multi-level median filter is presented. An image can be classified into two types of areas by using the direction information measure, that is. smooth area and edge area. Single direction multi-level median filter is used in smooth area. and multi-direction multi-level median filter is taken in the other type of area. What's more. an adaptive mechanism is proposed to adjust the type of the filters and the size of filter window. As a result. we get a better trade-off between preserving details and noise filtering.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.100-104
• /
• 1996

This paper describes the characteristics of micro-burr formation in the cross hatch and deburring in honed surfaces. Two types of micro-burrs formed in the cross hatch were defined as upper edge burr (type A) and side edge burr (type B). The size of micro-burrs were measured for the honed surfaces of several cross hatch angle. Deburring mechanism and system using magneto-electrolytic process including the abrasive pad for mechanic deburring effects together were introduced. Deburring experiments and analysis were carried out to confirm the effectiveness of the deburring process.

• 한국레이저가공학회지
• /
• 제18권3호
• /
• pp.6-8
• /
• 2015

Finishing process includes deburring, polishing and edge radiusing. It improves the surface profile of specimen and eliminates the alien substance on surface. Deburring is the elimination process for debris of edges. Polishing lubricates surfaces by rubbing or chemical treatment. There are two types for electron finishing. The one is using pulse beam. The other is using the convergent and scanning electron beam. Pulse type device appropriates the large area process. But it does not control the beam dosage. Scanning type device has advantages for dosage control and edge deburring. We design the convergence and scan type. It has magnetic lenses for convergence and scan device for scanning beam. Magnetic lenses consist of convergent and objective lens. The lenses are designed by the specification(beam size and working distance). In this paper, we evaluate the convergence performance by pattern process. Also, we analysis the results and important factors for process. The important factors for process are beam size, pressure, stage speed and vacuum. These results will be utilized into systematizing pattern shape and the factors.

• 대한기계학회논문집
• /
• 제12권1호
• /
• pp.173-182
• /
• 1988

A program for drawing of penetrating lines was developed in personal computer. PROLOG, a language of Artificial Intelligence, was used and a data structure using relational data base was designed. An algorithm for finding the penetrating lines in the real space was developed. The program can be applied at any types of penetrating problems like curve-surface, surface-surface, curve-object, surface-object, object-object, etc. In developing the program, the following results were obtained. (1) Relational data base built in PROLOG and the function of backtracking are helpful in Computer Graphics. (2) In spite of increasing the number of edges, assigning direction to the edges makes it possible to represent the polygon meshes as the non ordered sets of directional half edges. (3) Topologicaly the penetrating lines of a polygon can be represented as the edge-pairs in the edge list of the polygon,

• 한국전기전자재료학회논문지
• /
• 제24권4호
• /
• pp.261-265
• /
• 2011

This paper describes the fabrication and characteristics of a Au/Ni/Ti/3C-SiC Schottky diode with field plate (FP) edge termination. The Schottky contacts were annealed for 30 min at temperatures ranging from 0 to $800^{\circ}C$. At annealing temperature of $600^{\circ}C$, it showed an inhomogeneous Schottky barrier and had the best electrical characteristics. However, the annealing of $800^{\circ}C$ replaced it with ohmic behaviors because of the formation of many different types of nickel silicides. The fabricated Schottky diode had a breakdown voltage of 200 V, Schottky barrier height of 1.19 eV and worked normally even at $200^{\circ}C$.

• Structural Engineering and Mechanics
• /
• 제56권5호
• /
• pp.797-811
• /
• 2015

An analytical-computational method along with finite element analysis (FEA) has been employed to analyse the dynamic behaviour of deteriorated structures excited by time- varying mass. The present analysis is focused on the comparative study of a double cracked beam with inclined edge cracks and transverse open cracks subjected to traversing mass. The assumed computational method applied is the fourth order Runge-Kutta method. The analysis of the structure has been carried out at constant transit mass and speed. The response of the structure is determined at different crack depth and crack inclination angles. The influence of the parameters like crack depth and crack inclination angles are investigated on the dynamic behaviour of the structure. The results obtained from the assumed computational method are compared with those of the FEA for validation and found good agreements with FEA.