• 한국음향학회:학술대회논문집
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• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
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• pp.107-110
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• 1992

We investigate the influence of individual properties of piezoceramics such as elastic, dielectric, piezoelectric constants, and the coupling factor on the performance of the transducer operating in thickness mode oscillation. The investigation employs equivalent circuit analysis techniques. Appropriate transfer functions are obtained and discussed which suggest optimum selection guides of piezoelectric ceramics for each purpose, i.e. a transmitter, a receiver, and a pulse-echo transducer. The guides can help ceramic scientists find the direction to proceed in new material development.

• Applied Biological Chemistry
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• 제41권4호
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• pp.261-264
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• 1998

Differently substituted styrylquinoline derivatives (6-9) were synthesized by condensation of quinaldine (1) and corresponding substituted benzaldehydes (2-5). Their relative configuration at C11-C12 and coupling patterns were determined by NMR techniques.

• 대한전자공학회논문지
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• 제27권5호
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• pp.699-708
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• 1990

This paper proposes two test procedures for detecting functional faults in semiconductor random access memories (RAM's) and a new testimg scheme to execute the proposed test procedures. The first test procedure detects stuck-at faults, coupling faults and decoder faults, and requires 19N operations, which is an improvement over conventional procedures. The second detects restricted patternsensitive faults and requires 69N operations. The proposed scheme uses Built-In Self Testing (BIST) techniques. The scheme can write into more memory cells than I/O pins can in a write cycle in test mode. By using the scheme, the number of write operations is reduced and then much testing time is saved.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.295-301
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• 2002

In this paper, solenoid-type 3-D passives (inductors and transformers) have been designed, fabricated, and characterized by using electroplating techniques, wire bonding techniques, multi-layer thick photoresist, and low temperature processes which are compatible with semiconductor circuitry fabrication. Two different fabrication approaches are performed to develop the solenoid-type 3-D passives and relationship of performance characteristics and geometry is also deeply investigated such as windings, cross-sectional area of core, spacing between windings, and turn ratio. Fully integrated inductor has a quality factor of 31 at 6 GHz, an inductance of 2.7 nH, and a self resonant frequency of 15.8 GHz. Bonded wire inductor has a quality factor of 120, an inductance of 20 nH, and a self resonant frequency of 8 GHz. Integrated transformers with turn ratios of 1:1 and n:l have the minimum insertion loss of about 0.6 dB and the wide bandwidth of a few GHz.

• Transactions on Electrical and Electronic Materials
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• 제8권1호
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• pp.1-4
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• 2007

This paper discusses two approaches for pre-polishing optimization of oxide chemical mechanical planarization (CMP) that can be used as alternatives to the commonly applied dummy structure insertion in shallow trench isolation (STI) and replacement gate (RG) technologies: reverse nitride masking (RNM) and oxide etchback (OEB). Wafers have been produced using each optimization technique and CMP tests have been performed. Dishing, erosion and global planarity have been investigated with the help of conductive atomic force microscopy (C-AFM). The results demonstrate the effectiveness of both techniques which yield excellent planarity without dummy structure related performance degradation due to capacitive coupling.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.311-314
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• 1997

According to the development of industrial equipment such as semiconductor manufacturing machines, optical device, and precision machine tool, a high-precision translation system with wide range has been required. This paper describes a high-precision 2-axis translation system, which consists of microstage and global stage. In order to achieve the highresolution in the long range, some engineering techniques are used. Three linear guides with flexible coupling are adopted to reduce the motor vibration in the global stage. A simple elastic hinge structure activated by five PZT is applied to reduce the angular dev~atlon. As the result of combination of microstage and global stage associated with some engineering techniques, the 2-axis translation system can measure the 200 X 200 mrn range with the nanometer accuracy.

• 한국전자거래학회지
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• 제8권2호
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• pp.113-129
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• 2003

컴포넌트 기반 소프트웨어 개발(CBSD: Component Based Software Development)이 재사용을 통한 소프트웨어 개발의 효율적인 방법으로 인식되고 있다. CBSD의 목적은 새로운 시스템을 개발하고자 할 때 검증된 컴포넌트, 검증된 업무 로직을 재사용 함으로써 개발 기간을 단축하고 품질을 향상하고자 하는 것에 있다. 본 논문에서는 기 존재하는 객체지향 어플리케이션을 폐기하지 않고, 이를 기반으로 재사용 성이 높은 컴포넌트로 추출하기 위하여, 컴포넌트 추출을 위한 메트릭과 인터페이스 추출 방안을 제시하였다. 클래스간의 관계 정보를 이용하여 복잡도, 응집도와 결합도를 측정하고, 이의 결과를 이용하여 후보 컴포넌트를 추출한다.

• Journal of electromagnetic engineering and science
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• 제2권2호
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• pp.124-127
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• 2002

A RF tunable bandpass filter using dielectric resonators and varactor diodes is redesigned to improve the passband flatness. Since the tunable liters are generally of narrow bandwidth and the Q value of the varactor diode is usually very low, the passband flatness is strongly deteriorated by sizeable distortion loss. To remedy this problem, we construct modified Chebyshev type filter by use of network synthesis techniques. The key of modified Chebyshev type filter is the rearrangement of the passband poles to improve the passband flatness. To maintain the constant passband bandwidth, design techniques of input/output stage and coupling windows are also applied. Experimental results show that the passband flatness can be improved by purposed method without any additional RF amplitude equalizer.

• Journal of Ship and Ocean Technology
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• 제9권1호
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• pp.38-46
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• 2005

Survivability improvement method for naval ship design has been continually developed. In order to design naval ships considering survivability, it is demanded that designers should establish reasonable damage conditions by air explosion. Explosion may induce local damage as well as global collapse to the ship. Therefore possible damage conditions should be realistically estimated in the design stage. In this study the authors used ALE technique, one of the structure-fluid interaction techniques, to simulate air explosion and investigated survival capability of damaged naval ships. Lagrangian-Eulerian coupling algorithm, equation of the state for explosive and air, and simple calculation method for explosive loading were also reviewed. It is shown that air explosion analysis using ALE technique can evaluate structural damage after being attacked. This procedure can be applied to the real structural design quantitatively by calculating surviving time and probability.

• Elastomers and Composites
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• 제34권4호
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• pp.299-314
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• 1999

Bonding metal and textile components to rubber has always posed a problem. In this paper, an attempt had been made to modify textile and metal surfaces for bonding with rubber. The metal surfaces were modified using silane coupling agents and textile fibers were modified using plasma polymerization techniques. Some results on adhesion of metals to a range of sulfur-cured rubber compounds using a combination of organofunctional silanes are given here. The treatment was not only effective for high-sulfur compounds but also for low-sulfur com pounds as used in engine mounts and even for some semi-EV compounds. Coatings of plasmapolymerized pyrrole or acetylene were deposited on aramid and polyester tire cords. Standard pull-out force adhesion measurements were used to determine adhesion of tire cords to rubber compounds. The plasma coatings were characterized by various techniques and the performance results are explained in an interpenetrating network model.