• International Journal of Concrete Structures and Materials
• /
• 제2권1호
• /
• pp.21-25
• /
• 2008

Surface treatments act as a barrier between the environment and the concrete, preventing or retarding the entry of harmful substances and cutting off the transportation path into concrete. The effectiveness of a surface protection preventing the permeation depends on how close and strongly connected are the resin molecules. This work intends to contribute to a better understanding of the performance of protected concrete in chemically aggressive environments, by presenting results of ion diffusion and resistance to aggressive solutions of several hydrophobic agents and coatings used to protect concrete. Three different types of surface protections were tested: silicone hydrophobic agent, acrylic and epoxy coatings. The obtained results indicate that the overall performance of epoxy resin was better than the other selected types of protections.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권2호
• /
• pp.204-209
• /
• 2016

The analyses on self-heating effect in 7 nm node non-rectangular Bulk FinFET device were performed using 3D device simulation with consideration to contact via and pad. From self-heating effect simulation, the position where the maximum lattice temperature occurs in Bulk FinFET device was investigated. Through the comparison of thermal resistance at each node, main heat transfer path in Bulk FinFET device can be determined. Self-heating effect with device parameter and operation temperature was also analyzed and compared. In addition, the impact of interconnects which are connected between the device on self-heating effect was investigated.

• Journal of applied mathematics & informatics
• /
• 제31권5_6호
• /
• pp.595-608
• /
• 2013

Let G = (V, E) be a simple connected graph. The sets of vertices and edges of G are denoted by V = V (G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. The distance between the vertices $u$ and $v$ in V (G) of graph G is the number of edges in a shortest path connecting them, we denote by $d(u,v)$. In graph theory, we have many invariant polynomials for a graph G. In this paper, we focus on the Schultz polynomial, Modified Schultz polynomial, Hosoya polynomial and their topological indices of a molecular graph circumcoronene series of benzenoid $H_k$ and specially third member from this family. $H_3$ is a basic member from the circumcoronene series of benzenoid and its conclusions are base calculations for the Schultz polynomial and Hosoya polynomial of the circumcoronene series of benzenoid $H_k$ ($k{\geq}3$).

• 한국통신학회논문지
• /
• 제24권10B호
• /
• pp.1807-1814
• /
• 1999

본 논문은 고장 감내형 셔플스위치망에서 단순스위치의 고장에 따른 교환시스템의 성능저하를 특성화하기 위한 연결성 관련 신뢰성 척도를 다루고 있다. 상호 연결 가능한 평균 입출력 쌍의 수, 최소한 한 개 이상의 출력으로 연결 가능한 평균 입력의 수, 그리고 한 개 이상의 출력과 연결된 입력으로부터 실제 연결 가능한 평균 출력의 수를 연결성 척도로 고려한다. 단일경로 SEN과 이를 고장 감내화시킨 SEN+ 및 INDRA망에 대해 언급된 세가지 연결성 척도에 대한 평가방법을 제시한다. 이를 바탕으로 수치실험을 통한 망들의 비교, 분석이 이루어진다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1023_1024
• /
• 2009

In this paper, a novel 10kV, 50A, 50kHz pulsed power supply based on IGBT stacks is proposed. Proposed scheme consists of series connected 12 IGBT to generate maximum 10kV output pulse and 10kW full bridge phase-shifted zero voltage switching converter to charge DC capacitor voltage. Each IGBTs are sustain the 830V of capacitor voltage at turn off interval. By turn on the each IGBT for the same time it gives the path for the series connection of charged capacitor. From above turn on and off procedure, high voltage repetitive pulse is applied to the load. The synchronization of gating signal is important of series operation of IGBTs. For gating signal synchronization, specially designed gate power circuit using full bridge inverter and pulse transformer is developed to generate IGBT gating signal.

• 대한수학회논문집
• /
• 제24권2호
• /
• pp.161-169
• /
• 2009

In this paper, we introduce the generalized ideal-based zero-divisor graph structure of near-ring N, denoted by $\widehat{{\Gamma}_I(N)}$. It is shown that if I is a completely reflexive ideal of N, then every two vertices in $\widehat{{\Gamma}_I(N)}$ are connected by a path of length at most 3, and if $\widehat{{\Gamma}_I(N)}$ contains a cycle, then the core K of $\widehat{{\Gamma}_I(N)}$ is a union of triangles and rectangles. We have shown that if $\widehat{{\Gamma}_I(N)}$ is a bipartite graph for a completely semiprime ideal I of N, then N has two prime ideals whose intersection is I.

• Kyungpook Mathematical Journal
• /
• 제52권4호
• /
• pp.513-519
• /
• 2012

For a spanning tree T of a connected graph ${\Gamma}$ and for a labelling ${\phi}$: E(T) ${\rightarrow}$ {+,-},${\phi}$ is called an alternating sign on a spanning tree T of a graph ${\Gamma}$ if for any cotree edge $e{\in}E({\Gamma})-E(T)$, the unique path in T joining both end vertices of e has alternating signs. In the present article, we prove that any graph has a spanning tree T and an alternating sign on T.

• 한국전자통신학회논문지
• /
• 제6권2호
• /
• pp.274-279
• /
• 2011

이동통신 시스템의 성능을 증가시키기 위해서 다중안테나 기술 중의 하나인 빔포밍(beamforming) 기술을 적용하고자 하는 노력들이 많이 이루어지고 있다. 이러한 빔포밍 기능을 수행하기 위해서는 여러 RF 안테나 패스간의 위상 및 진폭차를 주기적으로 보정해 주는 절차가 필요한데, 이를 RF-패스 보정절차(calibration) 라고 한다. 하지만, 현재 Mobile WiMAX 기지국에서 사용되고 있는 RF-패스 보정 방법은 중계기가 연결될 때에 문제가 발생될 수 있다. 본 논문에서는 이러한 문제점을 기술하고 이를 해결하기 위한 새로운 보정절차 방법을 제시한다.

• 한국정밀공학회지
• /
• 제20권9호
• /
• pp.166-172
• /
• 2003

Vibration and Noise of air conditioner are entirely determined by compressor vibration. Compressor vibration transmitted to the enclosure of air conditioner or pipes connected compressor with heat exchanger. Enclosure generate(noise and vibration. Therefore, the analysis of compressor vibration analysis is considered significant technical issue. For the reduction of vibration of compressor, it is necessary to grasp correctly vibration transmission paths and excitation sources in the compressor shell. Because, shell ( Surface of compressor ) shows whole vibration characteristic of compressor mechanism. In this paper, vibration intensity was applied to measure vibration energy flow on the shell .From this technique, it is possible to catch the path of vibration propagation along the one cycle and the location of vibration energy sources may change with time on the shell.

• Smart Structures and Systems
• /
• 제11권2호
• /
• pp.185-197
• /
• 2013

We developed a simultaneous strain measurement and damage detection technique using a pair of surface-mounted piezoelectric transducers and a fiber connecting them. This is a novel sensor configuration of the fiber acoustic wave (FAW) piezoelectric transducer. In this study, lead-zirconate-titanate (PZT) transducers are installed conventionally on a plate's surface, which is a technique used in many structural health monitoring studies. However, our PZTs are also connected with an optical fiber. A FAW and Lamb wave are simultaneously guided in the optical fiber and the structure, respectively. The dependency of the time-of-flight of the FAW on the applied strain is quantified for strain sensing. In our experimental results, the FAW exhibited excellent linear behavior and no hysteresis with respect to the change in strain. On the other hand, the well-known damage detection function of the surface-mounted PZT transducers was still available by monitoring the waveform change in the conventional Lamb wave ultrasonic path.