• 한국산업보건학회지
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• 제15권3호
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• pp.202-212
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• 2005

This study was aimed at rating the existing work environment noise components and alternatives in point of worker's view. To answer the purpose, AHP(Analytic Hierarchy Process) method is adopted in this research. Based on the AHP method, this research abstracts a mathematically rigorous noise components and alternative's weights and proven process for priority and decision-making. By reconstructing complex hearing conservation programs to a series of pair-wise comparisons, and then synthesizing the results, this study not only helps establishments of noise countermeasure, but also provides a clear rationale for noise alternatives. The result of this study is summarized as follows; 1) Job satisfaction index and noise identification index are 63, 56 respectively. 2) Noise level(15.7%), frequency(14.1%) and directivity(13.6%) are main reasons in worker's ground. 3) There are some difference between the estimation of worker's identification and that of work sites. 4) Low noise machine(14.7%), enclosure(13.2%) and shielding(9.6%) are chosen for noise protection method by workers. 5) Noise environment improvement should be focused on noise source rather than personal protection. 6) By the AHP method, noise source countermeasure have a key role at work environments.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.646-649
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• 2002

In this paper, a low-voltage CMOS squarer and a four-quadrant analog multiplier are presented. It is based on a source-coupled pair and a scaled-floating voltage generator which are modified to work as a voltage squaring and a sum/difference circuits. The proposed squarer/multiplier have been simulated with HSPICE, where -3㏈ bandwidth of 10MHz is achieved. The power consumption is about 0.6㎽, from a ${\pm}$1.5V supply, and the total harmonic distortion is less than 0.7%, with a 1.2V peak-to-peak 1MHz input signal.

• Journal of applied mathematics & informatics
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• 제29권5_6호
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• pp.1205-1219
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• 2011

In this work, a stabilized characteristic finite volume method for the time-dependent Navier-Stokes equations is investigated based on the lowest equal-order finite element pair. The temporal differentiation and advection term are dealt with by characteristic scheme. Stability of the numerical solution is derived under some regularity assumptions. Optimal error estimates of the velocity and pressure are obtained by using the relationship between the finite volume and finite element methods.

• 기술사
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• 제38권2호
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• pp.60-63
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• 2005

Firstly, the author suggests a new term of the "Pro-Engineer's Doctrine" on every engineering work. This renewed term should be in their minds who are doing any kinds of scientific and technological works in his/her field. The term, "doctrine", is based on a wise sage, renewedly, so-called "The Way of the measuring squire(혈矩之道)" saying in one of the Oriental classics. Also, he explains here another term, "Investigation of things, attainment of knowledge(格物致知)" that is very similarity to the "Pro-Engineer's Doctrine" from the same book.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.86.6-86
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• 2002

This work presents a study on development of a practical and quantitative technique for assessment of the healthy state of a structure by piezoelectric impedance-based technique associated with longitudinal wave propagation measuring method. A truss structure embedded with piezoelectric patches is investigated for a fundamental study on estimation of the looseness of bolts in the joint. In order to evaluate the minute mechanical impedance change due to loosening bolt, a harmonic longitudinal elastic wave is applied to the structure by a pair of PZT patches and their electric impedance is measured simultaneously. According to the experimental results, the change of the electric impedance of P...

• 대한수학회논문집
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• 제32권4호
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• pp.885-898
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• 2017

The Bailey lemma has been a powerful tool in the discovery of identities of Rogers-Ramanujan type and also ordinary and basic hyper-geometric series identities. The mechanism of Bailey lemma has also led to the concepts of Bailey pair and Bailey chain. In the present work certain new WP-Bailey pairs have been established. We also have deduced a number of basic hypergeometric series identities as an application of new WP-Bailey pairs.

• 천문학회보
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• 제38권1호
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• pp.43.2-43.2
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• 2013

The local environmental effects on the triggering of active galactic nucleus(AGN) activity has been studied with many authors, but there still be controversy. We perform statistical analysis for nearby(0.01 < z < 0.05) volume limited(Mr < -19) samples with visual inspection based on Sloan Digital Sky Survey Data Release7. We inspect ~60,000 galaxy images visually to find peculiar objects which show not only ongoing merging features and tidal features, but also post merging features like ring or shell structures. We found that these peculiar features were shown at least 2 times more frequently among AGN host galaxies than non AGN galaxies, and this trend was still visible when galaxy properties such as color or stellar mass are fixed. Furthermore, L[OIII] and L(Ha) of peculiar galaxies are found to be more increased than those of normal galaxies. In order to ensure this results, we also checked it for a smaller subsample with ~2mag deeper monochromatic images provided from SDSS Stripe82 database, and found consistent results. At last, we perform the same work for pair(r_p<80kpc/h, delta_v<200km/s) systems. Because of some pair systems which do not interact gravitationally in actuality but fulfill the criteria for identification of pair system, the trends are found to be slightly weaker. We also found that line luminosities are increased consistently as projected distance between central and companion galaxy decreased, and as companion color gets bluer. Overall, the results of this study tell us that the local environment of galaxies affect the frequency as well as the strength of AGN activity. Local environmental effects, however, may not be the dominant triggering mechanism for AGN activity since the majority of peculiar galaxies are non AGN galaxies.

• 디지털융복합연구
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• 제13권5호
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• pp.205-211
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• 2015

최근 이동통신망과 휴대단말기가 급격하게 발전하게 되면서 모바일 오피스 서비스가 점점 각광을 받고 있다. 그러나, 사용자가 모바일 오피스환경에서 업무를 수행할 때 원격에 있는 자료를 업/다운로드 할 경우 제3자로부터 악의적인 공격을 받을 수 있다. 본 논문에서는 모바일 오피스 환경에서 사용되는 개인정보 및 기업정보(통화내역, 수신메시지, 전화번호부, 일정, 위치정보, 금융거래정보, 서류 등)를 담고 있는 스마트폰의 도난 분실로 인한 정보유출 예방 기법을 제안한다. 제안 기법에서는 개인정보 및 기업 정보의 상태정보를 삼각퍼지수를 이용하여 쌍대비교 행렬로 구현한다. 특히, 제안 기법은 쌍대비교 행렬로 구한 값을 개인정보 및 기업 정보와 쌍으로 구성하여 스마트폰 분실시 제3자가 개인정보 및 기업 정보를 확인할 수 없도록 하여 외부로 유출하는 것을 예방한다.

• 천문학논총
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• 제10권1호
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• pp.79-90
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• 1995

The unique compact radio source, Sgr $A^*$, at the Galactic center show many observational signs that it is powered by supermassive black hole. Recent observations also imply that it is surrounded by winds from nearby IR sources. So we explore the model in which multiwavelength spectrum from Sgr $A^*$ is due to the spherical accretion of these winds onto the central supermassive black hole. Improving upon the previous work, we allowed the possibility that ions and electrons have different temperatures, included the Compton effects and pair processes. Electrons radiate via cyclosynchrotron and bresstrahlung with comptoniztion. We find that ion approaches the virial temperature ${\sim}10^{13}K$ while electron temperature saturates at ${\sim}10^{10}K$. However, decoupling between ion and electron does not greatly affect the shape of the emission spectrum. When the mass of the black hole is ${\sim}10^6M_{\odot}$, radio, IR, X-ray, $\gamma$-ray band spectrum is reasonably explained by the model. Yet Compton effect which is neglected in previous works produces significant emission in IR band, which is marginally compatible with observations. Pair production is negligible and annihilation lines cannot be observed.

• Journal of Computing Science and Engineering
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• 제10권3호
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• pp.85-94
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• 2016

We propose a model-based method for information alignment using educational standards as a case study. Discrepancies and inconsistencies in educational standards across different states/cities hinder the retrieval and sharing of educational resources. Unlike existing educational standards alignment systems that only give binary judgments (either "aligned" or "not-aligned"), our proposed system classifies each pair of educational standard statements in one of seven levels of alignments: Strongly Fully-aligned, Weakly Fully-aligned, Partially-$aligned^{***}$, Partially-$aligned^{**}$, Partially-$aligned^*$, Poorly-aligned, and Not-aligned. Such a 7-level categorization extends the notion of binary alignment and provides a finer-grained system for comparing educational standards that can broaden categories of resource discovery and retrieval. This study continues our previous use of mathematics education as a domain, because of its generally unambiguous concepts. We adopt a materialization pattern (MP) model developed in our earlier work to represent each standard statement as a verb-phrase graph and a noun-phrase graph; we align a pair of statements using graph matching based on Bloom's Taxonomy, WordNet, and taxonomy of mathematics concepts. Our experiments on data sets of mathematics educational standards show that our proposed system can provide alignment results with a high degree of agreement with domain expert's judgments.