• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.257-260
• /
• 1998

In this paper, we describe an IMT-2000 system architecture, a protocol stack, and basic MAP scenarios(e.g., registration, call delivery) based on the IS-41 and IS-41 and IS-751. This paper focuses on the MAP scenarios to support the IMSI which is defined for the global roaming between GSM and IS-41 Networks through the Family of System approach. This paper also deals with the design of the MAP protocol stack transported over the ATM networks and introduces the software structure of MAP in IMT-2000 MSC.

• 전기학회논문지P
• /
• 제58권4호
• /
• pp.609-614
• /
• 2009

A fuel-cell power system among various alternative power sources has many advantages such as comparatively independable circumstances, high-efficient, and heat-recyclable, thus it is now able to be up to hundreds MWh-scaled through improving feasibility and longevity of it. During the last few decades, numerous research results has been investigated to expand interest in fuel-cell technology. This study presents pressure distribution on the geometrical manifold structures, which are U-type and Z-type, of a planar-type fuel-cell stack by simulated with computational fluid dynamics(CFD). Then, electrical performance of a 200W fuel-cell stack, which is U-type, was diagnosed after pre-conditioning operation. The stack has electrical characteristics ; 22V, 10A, 220W, and current density $200mA/cm^2$.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 추계학술대회논문집 I
• /
• pp.371-375
• /
• 2001

The concept of a new linear motor that uses piezo-stack actuator is demonstrated. The working principle is far different from the conventional inchworm motor. This motor is based on the self-moving cell concept. The linear motor has three cells and each cell is constructed with one piezo-stack actuator and a shell structure. A cell train is constructed by connecting these cells and the cell train is fitted into a guide way with a proper interference. The cell train moves along the guide way, by activating each cell in succession. The moving motion of the motor is tested. Since this linear motor uses piezo-stack actuator with unified clamping cell, it can produce fast speed, high resolution and large push force.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 추계학술대회논문집
• /
• pp.649-654
• /
• 2003

This paper is focused on the research of the ultra precision linear motor by using piezo stack actuators. The development of linear motor which can be controlled nano or micro scale is necessary for the precision manufacturing. Self-moving-cell principle is used for the design of linear motor Self-moving-cell linear motor is consisted of three cell structures, and each cell has two shells and one piezo-stack actuator. Each cell can do clamping and moving by two shell structures. The shell structure deformation by piezo stack actuator can move the linear motor by losing the clamping between the shall and guideway. This paper presents the design, manufacturing and test of the motor.

• 전기전자학회논문지
• /
• 제23권3호
• /
• pp.1015-1019
• /
• 2019

본 논문에서는 트리거 전압과 감내 특성을 개선시키기 위해 HHVSCR의 구조적 변경을 바탕으로 Stack 기술을 적용한 새로운 ESD 보호 소자를 제안한다. 우선 HHVSCR과 제안된 ESD 보호 소자를 비교하여 트리거 전압과 홀딩 전압, 감내 특성을 확인하였고 게이트 길이에 대한 변수를 추가하였다. 마지막으로, 제안된 ESD 보호 소자와 Stack을 적용한 소자를 비교하여 트리거 전압과 홀딩 전압, 감내 특성을 비교하였다.

• 한국재료학회지
• /
• 제30권5호
• /
• pp.262-266
• /
• 2020

In this paper, we investigated the effect of the passivation stack with Al₂O₃, hydrogenated silicon nitride (SiN_x:H) stack and Al₂O₃, silicon oxynitride (SiON_x) stack in the n type bifacial solar cell on monocrystalline silicon. SiNx:H and SiON_x films were deposited by plasma enhanced chemical vapor deposition on the Al₂O₃ thin film deposited by thermal atomic layer deposition. We focus on passivation properties of the two stack structure after laser ablation process in order to improve bifaciality of the cell. Our results showed SiN_x:H with Al₂O₃ stack is 10 mV higher in implied open circuit voltage and 60 ㎲ higher in minority carrier lifetime than SiON_x with Al₂O₃ stack at Ni silicide formation temperature for 1.8% open area ratio. This can be explained by hydrogen passivation at the Al₂O₃/Si interface and Al₂O₃ layer of laser damaged area during annealing.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -2
• /
• pp.623-626
• /
• 2000

The purpose of this paper is to find an efficient solution for multiple constant multiplication (MCM) problem. Since the circuit structure can be represented as a directed acyclic graph, evolutionary computing is considered as an effective tool for optimization of circuit synthesis. In this paper, we propose a stack type operator as a chromosome element to synthesize a directed acyclic graph efficiently. This type of chromosome can represent a graph structure with a set of simple symbols and so we can employ the similar method to a conventional GA.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권5호
• /
• pp.2629-2650
• /
• 2019

It is important to construct fully homomorphic encryption with ciphertext matrix that makes fully homomorphic encryption become very nature and simple. We present a general design method of constructing fully homomorphic encryption whose ciphertext is matrix. By using this design method, we can deduce a fully homomorphic encryption scheme step by step based on a basic encryption scheme. The process of deduction is similar to solving equation and the final output result is a fully homomorphic encryption scheme with ciphertext matrix. The idea of constructing ciphertext matrix is ciphertexts stack, which don't simply stack ciphertexts together but is to obtain the desired homomorphic property. We use decryption structure as tool to analyze homomorphic property and noise growth during homomorphic evaluation. By using this design method, we obtain three corresponding fully homomorphic encryption schemes. Our obtained fully homomorphic encryption schemes are more efficient. Finally, we introduce the adversary advantage and improve the previous method of estimating concert parameters of fully homomorphic encryption. We give the concert parameters of these schemes.

• 전기전자학회논문지
• /
• 제22권3호
• /
• pp.836-841
• /
• 2018

본 논문에서는 대표적인 ESD 보호회로인 SCR, LVTSCR을 기반으로 하여 특정한 어플리케이션의 요구 전압에 맞추어 설계하기 위한 Stack 기술에 대하여 서술한다. 또한 기존 구조와는 다른 SCR 기반의 ESD 보호회로를 제시하여 Stack기술에 적용함으로써, 주요 파라미터인 트리거 전압과 홀딩 전압의 변동에 대하여 검증한다. 새로이 추가되는 SCR 기반의 보호 회로의 경우 추가적인 N+, P+ 영역의 삽입으로 인해 보다 높은 홀딩 전압을 갖는 ESD 보호회로이다. 또한 시놉시스사의 T-CAD 시뮬레이터를 이용하여 제안된 ESD 보호회로의 전기적 특성을 검증을 실시하였다.

• 전기전자학회논문지
• /
• 제23권1호
• /
• pp.338-341
• /
• 2019

본 논문에서는 대표적인 ESD 보호소자인 LVTSCR의 특성을 향상시킨 새로운 구조의 ESD소자를 제안하고 특정 application의 각 요구전압에 최적화된 설계를 위한 N-stack 기술에 대하여 검증한다. 주요 파라미터인 홀딩전압과 트리거전압에 대하여 특성을 파악하고 감내특성의 지표인 온도특성 또한 검증한다. well영역의 추가구성과 기생 npn BJT를 추가로 직렬 연결된 구조를 형성하여 보다 향상된 전기적 특성을 갖는다. 특성 검증을 위해 synopsys 사의 T-cad simulation tool을 이용하였다.