인천, 목포지역의 연약 점성토의 지반공학적 특성

이성열 ( Sungyeol Lee ),백원진 ( Wonjin Baek ),이현성 ( Hyunsung Lee ),이광찬 ( Kwangchan Lee ),이정훈 ( Junghoon Lee ),임길상 ( Gilsang Lim ),김대호 ( Daeho Kim ) 한국농공학회 2021 한국농공학회 학술대회초록집 Vol.2021 No.-

Real-time continuous-wave terahertz line scanner based on a compact 1 × 240 InGaAs Schottky barrier diode array detector

Han, Sang-Pil,Ko, Hyunsung,Kim, Namje,Lee, Won-Hui,Moon, Kiwon,Lee, Il-Min,Lee, Eui Su,Lee, Dong Hun,Lee, Wangjoo,Han, Seong-Tae,Choi, Sung-Wook,Park, Kyung Hyun The Optical Society 2014 Optics express Vol.22 No.23

Effects of clioquinol analogues on the hypoxia-inducible factor pathway and intracelullar mobilization of metal ions.

Kim, So Yeon,Lee, Myong Jin,Kim, Jeong Won,Na, Yu-Ran,Lee, Ho-Youl,Cho, Hyunju,Lee, Keun Byeol,Lee, You Mie,Lee, Cheolju,Park, Hyunsung,Yang, Eun Gyeong Pharmaceutical Society of Japan 2012 Biological & pharmaceutical bulletin Vol.35 No.12

<P>We previously found that clioquinol (CQ) increases functional hypoxia-inducible factor-1α (HIF-1α) with enhanced transcription of its target genes. Here we report that compounds derived from 8-hydroxyquinoline including CQ, broxyquinoline (BQ), iodoquinol (IQ) and chloroacetoxyquinoline (CAQ) promote neovascularization effectively based on chick chorioallantoic membrane assays. The CQ analogues induce stabilization of HIF-1α as well as enhance HIF-1-mediated vascular endothelial growth factor transcription. These analogues also exert inhibitory effects on the activity of prolyl and asparaginyl hydroxylations of HIF-1α in vitro. Despite metal ion-dependent restoration of the inhibited HIF-1α hydroxylase activity, the cellular HIF-1α-inducing effects of the CQ analogues are reversed to varying degrees by Zn(2+) and Fe(2+). While CQ and BQ are completely reversed by Zn(2+), co-administration of Zn(2+) and IQ has only a partial reversing effect. On the other hand, CAQ-mediated stabilization of HIF-1α is reversed by Fe(2+) but not by Zn(2+). These phenomena are found to coincide with elevation of the intracellular Zn(2+) and Fe(2+) levels by the CQ analogues, suggesting that metal ion effects on HIF-1α in cells likely reflect the differential transporting capability of the analogues.</P>

NFC based User Authentication Method in Smartwork Environment

Hyunsung Kim,Sung Woon Lee 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

With the advances of IT technology, the interest in smartwork is increasing by using various mobile devices through Internet services at anytime and anywhere. The introduction of smartwork to a company provides business efficiency, improves productivity and reduces costs, but security researches are required to solve a variety of security issues in it. For the secure user authentication, Won proposed a user authentication method using NFC in smartwork environment. However, this paper shows that Won’s method has some security problems, including weak against stolen verifier attack and replay attack and lack of message integrity, and proposes a new NFC based user authentication mechanism to solve the problems. The proposed mechanism could be used as a security building block in various smartwork environments including telework, mobile office, and so on.

An Evaluation of Property Tax Abatement Program in U.S.

Hyunsung Lee 한국도시행정학회 1995 도시 행정 학보 Vol.8 No.-

Synthesis of ultra-long hollow chalcogenide nanofibers

Lee, Kun-Jae,Song, Hanbok,Lee, Young-In,Jung, Hyunsung,Zhang, Miluo,Choa, Yong-Ho,Myung, Nosang V. Royal Society of Chemistry 2011 Chemical communications Vol.47 No.32

<P>Electrospinning and galvanic displacement reaction are combined to fabricate ultra-long hollow chalcogen and chalcogenide nanofibers in a cost-effective and high throughput manner. This procedure exploits electrospinning to fabricate ultra-long sacrificial nanofibers with controlled dimensions and morphology, thereby imparting control over the composition and shape of the nanostructures evolved during galvanic displacement reaction. It is believed to be a general route to form various ultra-long hollow semiconducting nanofibers.</P> <P>Graphic Abstract</P><P>Cost-effective, high throughput fabrication of ultra-long, hollow chalcogen and chalcogenide nanofiber synthesis by combining electrospinning and galvanic displacement reaction. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc12312b'> </P>

Multi-dimensional histone methylations for coordinated regulation of gene expression under hypoxia

Lee, Seongyeol,Lee, Jieon,Chae, Sehyun,Moon, Yunwon,Lee, Ho-Youl,Park, Bongju,Yang, Eun Gyeong,Hwang, Daehee,Park, Hyunsung Oxford University Press 2017 Nucleic acids research Vol.45 No.20

<P><B>Abstract</B></P><P>Hypoxia increases both active and repressive histone methylation levels via decreased activity of histone demethylases. However, how such increases coordinately regulate induction or repression of hypoxia-responsive genes is largely unknown. Here, we profiled active and repressive histone tri-methylations (H3K4me3, H3K9me3, and H3K27me3) and analyzed gene expression profiles in human adipocyte-derived stem cells under hypoxia. We identified differentially expressed genes (DEGs) and differentially methylated genes (DMGs) by hypoxia and clustered the DEGs and DMGs into four major groups. We found that each group of DEGs was predominantly associated with alterations in only one type among the three histone tri-methylations. Moreover, the four groups of DEGs were associated with different TFs and localization patterns of their predominant types of H3K4me3, H3K9me3 and H3K27me3. Our results suggest that the association of altered gene expression with prominent single-type histone tri-methylations characterized by different localization patterns and with different sets of TFs contributes to regulation of particular sets of genes, which can serve as a model for coordinated epigenetic regulation of gene expression under hypoxia.</P>

지방정부의 재산세감면제도의 운용에 대한 실증적 분석 - 미국 미시간주 50개 도시를 중심으로

이현성(Lee Hyunsung) 한국국정관리학회 2005 현대사회와 행정 Vol.15 No.1

  재산세감면제도는 지방정부에서 지역경제발전을 위하여 가장 널리 사용되고 있는 도구 중 하나이다. 재산세감면제도의 운용에 있어서 도시들 간에 편차가 존재함에도 불구하고, 도시의 어떠한 특성들이 재산세감면제도의 운용의 수준을 결정하는지 그리고 그 효과성에 대하여 논의가 거의 없어 왔다, 본 연구는 지방정부의 재정적 여건과 경제적 여건이 지방정부의 재산세감면제도의 운용에 어떻게 영향을 미치는가에 초점을 맞추고 있다.<BR>  지방정부의 재산세감면제도 활성화 정도와 지방정부의 재정적ㆍ경제적 여건간의 상관관계에 대한 회귀분석의 결과는 재산세감면정책이 공간적인 왜곡과 바람직하지 않은 형평성의 결과를 낳을 수 있다는 것을 보여주고 있다.

Ultra-long bismuth telluride nanoribbons synthesis by lithographically patterned galvanic displacement

Jung, Hyunsung,Rheem, Youngwoo,Chartuprayoon, Nicha,Lim, Jae-Hong,Lee, Kyu-Hwan,Yoo, Bongyoung,Lee, Kun-Jae,Choa, Yong-Ho,Wei, Peng,Shi, Jing,Myung, Nosang V. Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.44

<P>We demonstrated the wafer level batch synthesis and fabrication of single semiconducting thermoelectric nanoribbon based devices by Lithographically Patterned Galvanic Displacement (LPGD). The shape, composition, and dimension of nanoribbons were tailored by adjusting deposition conditions. High resolution TEM images with fast Fourier transform (FFT)-converted selected area electron diffraction (SAED) patterns confirmed the formation of polycrystalline Bi<SUB>2</SUB>Te<SUB>3</SUB> intermetallic compound with a rhombohedral structure without elemental Te and Bi. The thickness dependent electrical resistivity of Bi<SUB><I>x</I></SUB>Te<SUB><I>y</I></SUB> nanoribbons shows a classic size effect due to the increase in surface boundary scattering. The as-synthesized nanoribbons were n-type semiconductors with no clear trend between field effect carrier mobility and composition, which might be attributed to the trapped charges at the interface between the channel and dielectric layer. The preliminary results on thermoelectric properties (<I>i.e.</I> Seebeck coefficient and power factor) show that the Seebeck coefficient of as-synthesized 0.1 µm thick Bi<SUB>30</SUB>Te<SUB>70</SUB> nanoribbon is comparable with bulk counterparts, however, the power factor was lower because of poor crystallinity which leads to higher resistivity.</P> <P>Graphic Abstract</P><P>Wafer-scale synthesis of single semiconducting BiTe nanoribbons was demonstrated by Lithographically Patterned Galvanic Displacement with controlled composition and dimensions. Composition and size dependent material, electrical, and thermoelectrical properties were systematically investigated. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm02058c'> </P>

가상 전시의 몰입 향상을 위한 사용자 경험 요소에 관한 연구

이슬 ( Lee Seul ),이현성 ( Lee Hyunsung ),최익서 ( Choi Ikseo ) 한국공간디자인학회 2021 한국공간디자인학회논문집 Vol.16 No.6

(연구 배경 및 목적) 전시의 개념과 범위 확장, 기술과 전시의 접목, 그리고 코로나19 바이러스까지 여러 요인으로 인해 가상 전시가 등장했다. 가상 전시는 HCI(인간과 컴퓨터의 상호작용), 네트워크 기술, 시청각 정보를 활용한 연출 등 다양하고 복합적인 기술의 구현이 가능하다. 시공간의 제약이 없고, 누구나 쉽게 접근할 수 있으며, 소모되지 않는다는 장점도 있다. VR, AR 등 여러 종류의 가상 전시가 있지만, 대중적인 것은 360도 이미지 기반의 가상 전시다. 다수의 사용자는 2D 디스플레이 환경에서 가상 전시를 경험한다. 본 연구는 실제 전시 공간을 가상 현실에 재현한 360도 이미지 기반의 가상 전시를 대상으로 하며, 2D 그래픽 화면에서의 가상 전시 사용자 경험에 있어서 몰입 요소가 무엇인지 찾아보고자 한다. (연구방법) 본 연구는 다섯 단계로 진행됐다. 첫째, 이론적 고찰을 통해 가상 전시의 사용자(관람자) 경험 요소를 추출했다. 칙센트미하이의 플로우(Flow) 중 5개의 차원을 채택했고, 경험 요소는 물리적 요소와 비물리적 요소로 구분했다. 물리적 요소는 가상 전시 플랫폼의 기능 위주로 11개를 추출했고, 비물리적 요소는 선행 연구에서 25개의 항목을 추출해 번 슈미트의 체험 마케팅에 따라 '감각, 감성, 인지, 행동, 관계'로 분류했다. 둘째, 이론적 고찰을 통해 얻은 내용을 바탕으로 사용자 평가 항목을 설계했다. 셋째, 5개의 사례를 선정하고, 48명의 사용자에게 직접 사용해보게 한 후 설문조사-심층 인터뷰 순으로 진행했다. 넷째, 사용자 경험 평가 결과를 통계와 레더링 기법을 사용해 분석했다. 다섯째, 가상 전시의 몰입 향상에 필요한 사용자 경험 요소를 찾고, 결론에 도달했다. (결과) 즉각적인 피드백을 느끼게 하는 경험 요소는 '조작 툴'이며, 조작 툴은 '역동성'과 관계가 높은 것으로 나타났다. 조작 툴의 역동성을 방해하는 요소는 '플랫폼마다 다른 조작 툴', '정확성 부족' 등이 있었다. 행동과 인식이 통합을 느끼게 하는 경험 요소는 '플로어 가이드'이며, '행동유발성'과 관계가 높은 것으로 나타났다. 플로어 가이드의 행동을 방해하는 요소는 '360도 자동 회전', '자동 화면 확대' 등이 있었다. 과제에 대한 집중을 높여주는 경험 요소는 '미디어'이며, 미디어는 '흥미성'과 관계가 높은 것으로 나타났다. 미디어의 흥미를 떨어뜨리는 요소는 '낮은 선명도', '낮은 구현 수준' 등이 있었다. 제어감을 느끼게 하는 경험 요소는 '섬네일 맵'이며, 섬네일 맵은 '인식성'과 관계가 높은 것으로 나타났다. 섬네일 맵의 인식을 방해하는 요소는 '불필요한 이미지', '기능 부족' 등이 있었다. 자의식 상실, 변형된 시간 감각 등 완전한 몰입을 느끼게 한 경험 요소는 사용자의 47.9%가 '없다'고 응답했다. (결론) 즉각적인 피드백 향상을 위해 조작 툴의 통일성을 갖춰야 한다. 가상 전시의 개발 가이드라인 연구가 필요하다. 행동과 인식의 통합을 위해 정확도를 개선해야 한다. 사용자의 관점에서 위치의 재설정이 필요하고, 후진 이동 기능도 보완돼야 한다. 과제에 대한 집중을 높이기 위해서는 선명하고 높은 해상도와 왜곡 현상이 보완돼야 한다. 집중력 향상과 흥미 유발을 위해서는 실제 전시를 그대로 복제하는 것보다 디지털 미디어의 특성을 활용해야 한다. 사용자의 효율적인 제어를 위해 섬네일 맵의 기능이 보완돼야 하며, 화면 전환 시 어지러움을 유발하는 효과는 피해야 한다. 가상 전시는 공공성과 대중성을 확보하기 위해 가장 보편적인 2D 디스플레이 환경을 고려해야 하며, 사용자 경험 관점에서의 꾸준한 연구와 개발이 필요할 것이다. (Background and Purpose) Virtual exhibitions have emerged due to various factors including the concept and scope of the exhibition, the integration of technology and exhibition, and the coronavirus. Virtual exhibitions can be implemented in various and complex technologies such as HCI (Interaction between humans and computers), network technology, and directing using audiovisual information, and can be easily accessed by anyone. However, the limitations of VR and AR exhibitions are also pointed out. This study targets a 360-degree image based virtual exhibition that recreates the actual exhibition space into virtual reality and finds out what the immersion elements are in the user experience on the 2D graphics screen. (Method) The study was conducted in five stages. First, the user experience elements of the virtual exhibition were extracted through theoretical consideration. Five dimensions of Csiksentmihalyi's flow were adopted. Experience factors were divided into physical and non-physical factors. Second, User evaluation items were designed based on theoretical consideration. Third, Five cases were selected, and surveys and in-depth interviews were conducted for users. Fourth, the user experience evaluation results were analyzed. Fifth, a conclusion was reached by finding complementary points to improve the immersion of virtual exhibitions. (Results) The experience factors that make users feel immediate feedback are 'operating tools', which is highly related to 'dynamicity'. Factors that interfere with the dynamics of operating tools are 'different operating tools on different platforms', 'lack of accuracy'. The experience factor that makes behavior and awareness feel integrated is the 'Floor Guide', which is highly related to 'action-induced'. Some of the obstacles to user behavior are 'auto-rotation', 'auto-screen magnification'. The experience factors that increases concentration is "media," and has a high relationship with 'interest'. Factors that dampen interest in the media are 'low clarity' and 'low deployment level'. Experience factors that make users feel controlled are 'thumbnail maps', which are highly related to 'recognition'. Factors that hindered the recognition of thumbnail maps are 'unnecessary images', 'lack of function'. 47.9% of users responded that there was no experience factor that made them feel completely immersed, with an average of 2.31 points for immersion and an average of 2.48 points for satisfaction. (Conclusions) Considering that the majority of users evaluated the degree of immersion low, the current virtual exhibition platform needs to improve immersion. It needs unification of manipulation tools for immediate feedback enhancement, supplementation of floor guides' accuracy and movement functions, improvement of distortion and media implementation according to viewing angles to improve concentration, simplifying images and specifying functions of thumbnail maps to implement media and improve potential control. Virtual exhibition should consider the most common 2D display environment to ensure publicity and popularity, and will require steady research and development from a user experience perspective.