• 한국멀티미디어학회논문지
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• 제11권9호
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• pp.1227-1237
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• 2008

본 논문에서는 널리 알려진 상호연결망인 하이퍼큐브의 망 비용을 개선한 폴디드 하이퍼스타 네트워크의 성질과 임베딩을 분석한다 폴디드 하이퍼스타 네트워크는 재귀적 확장성과 최대 고장 허용도를 갖는다. 임베딩의 연구 결과는 폴디드 하이퍼큐브 $FQ_n$와 $n{\times}n$ 토러스 구조를 폴디드 하이퍼스타 FHS(2n,n)에 연장율 2에 임베딩 가능하다. 또한, 폴디드 하이퍼스타 네트워크 FHS(2n,n)은 폴디드 하이퍼큐브 $FQ_{2n-1}$에 연장율 1에 임베딩 가능함을 보인다.

• 품질경영학회지
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• 제41권2호
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• pp.185-196
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• 2013

Purpose: This paper is focused on introducing the Automotive Functional Safety International Standard-ISO 26262 and proposing effective countermeasures of ISO 26262. Methods: We studied collected data about ISO 26262 and analyzed the relationship between ISO 26262 and Quality 5 Star of Hyundai Kia Motors for the integrated product development process. Results: Results showed the product development process for the integration plan between ISO 26262 and Quality 5 Star. In addition, we added an entry about the functional safety in the evaluation item of Quality 5 Star System. Conclusion: In order to introduce ISO 26262 effectively, we proposed ISO 26262 requirements and functional safety concept to be added to Quality 5 Star.

• 대한공간정보학회지
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• 제19권3호
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• pp.75-82
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• 2011

본 연구에서는 기존 위성항법시스템의 경우 고가의 장비보유, 통신장애에 따른 이용의 제한 등의 단점을 보완할 수 있는 광역보정위성항법시스템인 위성기반보정시스템(SBAS: Satellite Based Augmentation System)의 하나인 OmniSTAR의 개요, 고정해에의 수렴시간(convergence time)을 분석한 결과, 동적모드(Dynamic mode)에서 약 39분, 정적모드(Static mode)에서 약 28분 소요되는 것으로 나타났다. 본 연구의 성과는 높은 정확도를 요구하지 않는 위치기반서비스(LBS: Location Based Service) 분야, 모바일 측위분야, 공간정보산업분야에 활용될 수 있을 것으로 사료된다.

• 항공우주기술
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• 제5권2호
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• pp.90-101
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• 2006

자세제어계 센서 보정알고리즘을 이용하여 자이로와 별 추적기의 보정 파라미터를 추정하였다. 보정알고리즘은 칼만필터로 구현하였다. 자이로의 파라미터를 추정하기 위해서는 보정기동이 필요하며, 별 추적기의 요구조건 내에서 보정기동을 수행하였다. 보정기동 동안에 별 추적기가 태양, 지구, 달에 대해서 영향을 받는지를 분석을 하였다. 또한 별 추적기를 보정하기 위해서는 카메라 영상 정보를 이용하였다. 이러한 카메라 영상 정보는 지상 제어점과 인공위성의 궤도 정보를 이용하여 모사하였으며, 별 추적기 보정 파라미터 추정의 정밀도는 카메라 영상 정보의 정밀도에 따라 다르다.

• 전자공학회논문지A
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• 제30A권11호
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• pp.99-104
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• 1993

We analyzed the D.I. water used in wet cleaning process of semiconductor device manufacturing both at the D.I. water plant and at the wafer cleaning bath to detect the impurity source of D.I. water contamination. This shows that the quantity of impurity is related to the resistivity of D.I. water, and we found that the cleanliness of the wafer surface processed in D.I. water bath was affected by the degree of the ionic impurity contamination. So we evaluated the cleaning effect as different method for Fe ion, having the best adsoptivity on wafer surface. Moreover the temperature effect of the D.I. water is investigated in case of anion in order to remove the chemical residue after wet process. In addition to the control of D.I. water resistivity, chemical analysis of impurity control in D.I. water should be included and a suitable cleaning an drinsing method needs to be investigated for a high yielding semiconductor device.

• 천문학회보
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• 제36권1호
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• pp.82.2-82.2
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• 2011

Infra-Red Dark Clouds (IRDCs) seen silhouette against the bright Galactic background in mid-IR are a class of interstellar clouds that are dense and cold with very high column densities. While IRDCs are believed to be the precursors to massive stars and star clusters, individual IRDCs show diverse star forming activities within them. We report a remarkable example of such cloud, the IRDC at ${\Gamma}53.2^{\circ}$, and star formation activity in this cloud. The IRDC was previously identified in part as three separate, arcmin-size clouds in the catalogue of MSX IRDC candidates, but we found that the IRDC is associated with a long, filamentary CO cloud at 2 kpc from the Galactic Ring Survey data of $^{13}CO$ J = 1-0 emission, and that its total extent reaches ~ 30pc. The Spitzer MIPSGAL 24mm data show a number of reddened mid-IR sources distributed along the IRDC which are probably young stellar objects (YSOs), and the UWISH2 $H_2$ data (2.122mm) reveal ubiquitous out flows around them. These observations indicate that the IRDC is a site of active star formation with YSOs in various evolutionary stages. In order to investigate the nature of mid-IR sources, we have performed photometry of MIPSGAL data, and we present a catalogue of YSOs combining other available point source catalogues from optical to IR. We discuss the evolutionary stages and characteristics of YSOs from their IR colors and spectral energy distributions.

• Carbon letters
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• 제27권
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• pp.18-25
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• 2018

In this study, graphene oxide(GO) was used as drug carriers to amorphize poorly watersoluble drugs via a co-spray drying process. Two poorly water-soluble drugs, fenofibrate and ibuprofen, were investigated. It was found that the drug molecules could be in the graphene nanosheets in amorphous or nano crystalline forms and thus have a significantly enhanced dissolution rate compared with the counterpart crystalline form. In addition, the dissolution of the amorphous drug enwrapped with the graphene oxide was higher than that of the amorphous drug in activated carbon (AC) even though the AC possessed a larger specific surface area than that of the graphene oxide. The amorphous formulations also remained stable under accelerated storage conditions ($40^{\circ}C$ and 75% relative humidity) for a study period of 14 months. Therefore, graphene oxide could be a potential drug carrier and amorphization agent for poorly water-soluble drugs to enhance their bioavailability.

• Journal of Construction Engineering and Project Management
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• 제9권2호
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• pp.25-51
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• 2019

Green building certifications are being adopted widely, and existing research continues to show an array of benefits to stakeholders of green certified buildings. However, little attention has been paid thus far to the effects these buildings may have on their surrounding neighborhoods economically. This research examined the effect of LEED and/or Energy Star certification on the neighborhoods surrounding certified office buildings from an economic standpoint with spatial and statistical analyses. This research showed the unit market value of LEED and/or Energy Star certified office buildings and the parameters of LEED and/or Energy Star certification had statistically a positive impact on the median unit market value of their neighborhood areas. The findings can provide useful insights into the possibilities for additional economic benefits of their neighborhoods, encouraging a win-win approach that enhances the local real estate market.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2004년도 춘계학술발표대회
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• pp.1271-1274
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• 2004

현재 운용중인 대부분의 VPN은 모든 CPE(Customer Premise Equipment) VPN GW(Gateway)들이 Center VPN GW에 연결되어 있는 Star 구조를 취하고 있다. 이러한 구조에서는 모든 트래픽들이 항상 Center VPN GW를 거쳐서 전송되므로 비효율적인 트래픽 전송이 이루어진다. 또한 대용량의 멀티미디어 트래픽 전송이 빈번하거나 다수의 지점을 갖고 있는 기업의 경우 Center VPN GW에서의 오버헤드가 증가하게 된다. 이러한 문제를 해결하기 위한 방법으로는 IPSec의 IKE(Internet Key Exchange) 메커니즘을 이용하여 CPE VPN GW간 직접 터널을 맺어 줄 수 있으나, 터널 설립에 앞서 원격지 CPE VPN GW의 주소, 요구되는 보안 등급 등의 터널 설정에 필요한 정보를 관리자가 직접 설정해 주어야 한다. 이는 현재 DHCP와 같은 동적 IP 환경에서 운용되는 ADSL 기반의 VPN 환경에서 관리 오버헤드를 증가시키는 요인이 된다. 이에 본 논문에서는 CPE VPN GW 간 직접 터널 연결이 필요할 시에 자동적으로 제반 기능들이 수행될 수 있게 하는 주문형 터널 생성(On-demand Tunnel Creation) 메커니즘 제안한다. 시뮬레이션을 통해 제안하는 방안에 대하여 성능을 조사하였고, 이와 함께 기존의 Star VPN 구조, Full-mesh VPN 구조와 성능을 비교하였다. 시뮬레이션 결과, 제안하는 방안이 기존의 Star VPN 구조보다 확장성과 트래픽 전송효율성, Center VPN GW의 오버헤드 측면에서 우수한 성능을 보였으며 Full-mesh 구조의 VPN과 거의 비슷한 종단간 지연시간과 처리율을 보였다.

• 천문학회보
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• 제43권2호
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• pp.54.3-55
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• 2018

We present the physical and environmental properties of nearby dwarf elliptical-like galaxies. The present sample consists of ~ 1,100 dwarf elliptical-like galaxies within redshifts 0.01. The morphological types of the present study were determined by Ann, Seo, and Ha (2015) who classified the dwarf elliptical-like galaxies by the five subtypes of dS0, dE, dSph, dEbc, and dEblue. We examine their star formation history using STARLIGHT. The star formation history of dwarf elliptical-like galaxies depends on their subtypes. The luminosities of dS0, dE, and dSph galaxies are dominated by the extremely old stars (${\geq}10^{10}yr$) with $z{\approx}0.0004$ while those of dEbc and dEblue galaxies are mainly due to the young (${\sim}10^7yr$) stars together with the nearly equal contribution by extremely young stars (${\sim}10^6yr$) and old (${\sim}10^9yr$) stars. Young populations have a variety of metallicity, from z=0.0001 to z = 0.04, while old populations have metallicity of z = 0.0001 and z = 0.0004. While the formation history of stars older than ~1010yr depends mainly on the luminosity of galaxies, the formation history of stars younger than ~108yr is mainly affected by their environment. However, luminosity and environment are equally important for the star formation history if there is no star formation at the early phase of galaxy formation.