다중 싱크 센서 네트워크에서의 라이프타임 연장을 위한 에너지 효율적인 싱크 선택 기법

박진효(Jinhyo Park),정재탁(J.T Chung),정성원(S.W Chung),한기준(Kijun Han) 한국정보과학회 2006 한국정보과학회 학술발표논문집 Vol.33 No.2D

기존 single sink 센서 네트워크에서의 모든 센서 노드들은 sink로부터 flooding된 질의(query)를 전송 받은 후 센싱 data를 sink로 보냄에 있어서 목적지인 sink 주변 노드의 traffic 집중에 따른 에너지 소비로 인해 전체 네트워크 수명에 영향을 끼쳤다. 이러한 single sink 방식에서의 주변 노드의overhead와 센싱 데이터를 sink로 전달 할 때의 특정 경로상의 노드들의 잔여 에너지량을 고려하여 데이터를 전송하게 함으로써 전체 네트워크 수명을 연장 할 수 있다.

활성화 노드 선택 기법을 기반으로 한 효율적인 토폴로지 설계

정재탁(Jaetak Chung),박진효(Jinhyo Park),정성원(Wonsung Chung),한기준(Kijun Han) 한국정보과학회 2006 한국정보과학회 학술발표논문집 Vol.33 No.2D

무선 센서 네트워크에서 각 센서 노드는 에너지의 한계를 가지기 때문에, 에너지 소비문제는 매우 중요한 이슈이다. 조밀한 환경의 센서 네트워크에서 모든 노드들이 센싱에 참여한다면, 센싱영역의 중복영역이 커지게 되고, 이로 인해 불필요한 에너지를 소비하게 된다. 본 논문에서는 connectivity 와 coverage 를 보장할 수 있고, 효율적으로 활성화 노드를 선택할 수 있는 기법을 제안하여, 불필요한 센서 노드들의 에너지소비를 막아 전체적인 네트워크의 lifetime 을 연장시키고자 한다.

Fabrication and in vitro biocompatibilities of fibrous biocomposites consisting of PCL and M13 bacteriophage-conjugated alginate for bone tissue engineering

Lee, Jae Yoon,Chung, Jinhyo,Chung, Woo-Jae,Kim, GeunHyung The Royal Society of Chemistry 2016 Journal of Materials Chemistry B Vol.4 No.4

<P>As the M13 bacteriophage, which has integrin binding and calcium binding sites, provides topological cues from the nanofibrous shape and biochemical cues from the Arg-Gly-Asp (RGD) sequence attached to the surface of fibrous phage, it has been recommended as a bioactive component for use in bone tissue engineering. However, although it has good biological activities, its low mechanical properties and low processing ability represent major issues that must be overcome before its use as a tissue engineering substitute. To overcome these issues, we chemically conjugated the M13 bacteriophage and alginate with a cross-linking agent and it was used as a bioactive component on electrospun poly(ε-caprolactone) (PCL) micro/nanofibres. Assessment of the physical properties and<I>in vitro</I>biocompatibility using osteoblast-like cells indicated that the biocomposite supplemented with the conjugated phage/alginate was mechanically enhanced, and the extent of mineralisation of cells on the composite was significantly higher compared to that on the fibrous composites fabricated using physically mixed M13 phage/alginate and RGD-modified alginate. These results indicate that M13 phage-conjugated alginate may have potential to be used as an excellent bioactive component for bone tissue regeneration.</P>

MPSoC 플랫폼의 버스 에너지 절감을 위한 버스 분할 기법

정준목(Chun-Mok Chung),김진효(Jinhyo Kim),김지홍(Jihong Kim) 한국정보과학회 2006 정보과학회논문지 : 시스템 및 이론 Vol.33 No.9

버스 분할 기법은 통신이 많은 모듈들을 가까이 배치하고 필요한 버스 단편만 사용함으로 버스 에너지 소비를 줄인다. 그러나 MPSoC와 같은 다중 프로세서 플랫폼에서는 캐시 일관성을 유지하기 위하여 모든 프로세서에서 버스 트랜잭션을 알아야 하므로, 기존의 버스 분할 기법을 적용할 수 없다. 본 논문에서는 공유 메모리 기반의 MPSoC 플랫폼에서 버스 에너지를 절감시키기 위한 버스 분할 기법을 제안한다. 제안된 버스 분할 기법은 비 공유 메모리와 공유 메모리의 버스를 분할함으로써, 캐시 일관성을 유지하며 비 공유 메모리를 참조할 때 소비하는 버스 에너지를 최소화시킨다. 또한, 태스크별 버스 트랜잭션 횟수를 기반하여 태스크를 할당함으로써, 공유 메모리를 참조할 때 소비하는 버스 에너지를 절감시키는 캐시 일관성을 고려한 태스크 할당 기법을 제안한다. 시뮬레이션을 통한 실험에서 제안된 버스 분할 기법은 비 공유 메모리 참조시의 버스 에너지를 최대 83%까지 절감시키며, 태스크 할당 알고리즘은 공유 메모리 참조시의 버스 에너지를 최대 36%까지 절감시키는 효과가 있음을 보여준다. 그럼으로, 다중 프로세서 시스템에서도 버스 분할 기법을 적용하여 버스 에너지 절감 효과를 볼 수 있으며, 캐시 일관성을 고려한 태스크 할당 기법을 통해 추가적으로 버스 에너지를 절감할 수 있음을 보여준다. Bus splitting technique reduces bus energy by placing modules with frequent communications closely and using necessary bus segments in communications. But, previous bus splitting techniques can not be used in MPSoC platform, because it uses cache coherency protocol and all processors should be able to see the bus transactions. In this paper, we propose a bus splitting technique for MPSoC platform to reduce bus energy. The proposed technique divides a bus into several bus segments, some for private memory and others for shared memory. So, it minimizes the bus energy consumed in private memory accesses without producing cache coherency problem. We also propose a task allocation technique considering cache coherency protocol. It allocates tasks into processors according to the numbers of bus transactions and cache coherence protocol, and reduces the bus energy consumption during shared memory references. The experimental results from simulations say the bus splitting technique reduces maximal 83% of the bus energy consumption by private memory accesses. Also they show the task allocation technique reduces maximal 30% of bus energy consumed in shared memory references. We can expect the bus splitting technique and the task allocation technique can be used in multiprocessor platforms to reduce bus energy without interference with cache coherency protocol.

Biomimetic Self-Templated Hierarchical Structures of Collagen-Like Peptide Amphiphiles

Jin, Hyo-Eon,Jang, Jaein,Chung, Jinhyo,Lee, Hee Jung,Wang, Eddie,Lee, Seung-Wuk,Chung, Woo-Jae American Chemical Society 2015 NANO LETTERS Vol.15 No.10

<P>Developing hierarchically structured biomaterials with tunable chemical and physical properties like those found in nature is critically important to regenerative medicine and studies on tissue morphogenesis. Despite advances in materials synthesis and assembly processes, our ability to control hierarchical assembly using fibrillar biomolecules remains limited. Here, we developed a bioinspired approach to create collagen-like materials through directed evolutionary screening and directed self-assembly. We first synthesized peptide amphiphiles by coupling phage display-identified collagen-like peptides to long-chain fatty acids. We then assembled the amphiphiles into diverse, hierarchically organized, nanofibrous structures using directed self-assembly based on liquid crystal flow and its controlled deposition. The resulting structures sustained and directed the growth of bone cells and hydroxyapatite biominerals. We believe these self-assembling collagen-like amphiphiles could prove useful in the structural design of tissue regenerating materials.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-10/acs.nanolett.5b03313/production/images/medium/nl-2015-03313d_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5b03313'>ACS Electronic Supporting Info</A></P>

Hierarchically structured peptide nanofibers for colorimetric detection of gaseous aldehydes

Gong, Mi Sic,Oh, Gyuyeob,Chung, Jinhyo,Jang, Hyung-Seok,Lee, Byung Yang,Chung, Woo-Jae Elsevier 2019 Sensors and actuators. B, Chemical Vol.282 No.-

<P><B>Abstract</B></P> <P>We demonstrate a systematic approach to produce colored films based on hierarchical structures of peptide amphiphiles and their application for detecting gaseous aldehydes. Lysine-rich peptide amphiphiles (LRPAs) were designed to spontaneously self-assemble into nanofibers, which were deposited to form the colored films on solid substrates via controlled evaporation of the meniscus using a facile dipping-pulling method. The control of assembly conditions such as pH, concentration, and pulling speed enable the manifestation of film colors in a controllable way. When exposed to aldehyde gases, the color band pattern exhibited large color change due to structural change of the matrices which occur upon specific binding of aldehydes to lysine motifs. The statistical analysis of the color-change showed that the LRPA-based band patterns exhibit excellent selectivity toward aldehydes over non-aldehyde gases. We expect that our method will expedite the development of inexpensive, rapid and user-friendly aldehyde detection systems with on-site monitoring capabilities.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The study reports facile fabrication of colorimetric sensors for aldehyde gas detection. </LI> <LI> Lysine-rich peptide derivatives were assembled into banded colored pattern film. </LI> <LI> The color band pattern showed aldehyde concentration-dependent color change. </LI> <LI> The color change is attributed to the structural change of the film. </LI> <LI> This strategy offers great promise for inexpensive and user-friendly aldehyde detection systems. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Lysine-rich peptide amphiphiles (LRPAs) are designed to self-assemble into biomimetic colored structures on solid substrates, which can change in color when exposed to aldehyde gases. Other non-aldehyde gases can be discerned from aldehyde gases by analyzing their color changing patterns.</P> <P>[DISPLAY OMISSION]</P>

Gradient index lens based combined two-photon microscopy and optical coherence tomography

Wang, Taejun,Li, Qingyun,Xiao, Peng,Ahn, Jinhyo,Kim, Young Eun,Park, Youngrong,Kim, Minjun,Song, Miyeoun,Chung, Euiheon,Chung, Wan Kyun,Ahn, G-One,Kim, Sungjee,Kim, Pilhan,Myung, Seung-Jae,Kim, Ki Hea The Optical Society 2014 Optics express Vol.22 No.11

Envelope-deforming antiviral peptide derived from influenza virus M2 protein

Jung, Younghun,Kong, Byoungjae,Moon, Seokoh,Yu, Seok-Hyeon,Chung, Jinhyo,Ban, Choongjin,Chung, Woo-Jae,Kim, Sung-Gun,Kweon, Dae-Hyuk Elsevier 2019 Biochemical and biophysical research communication Vol.517 No.3

<P><B>Abstract</B></P> <P>Molecules interfering with lipid bilayer function exhibit strong antiviral activity against a broad range of enveloped viruses, with a lower risk of resistance development than that for viral protein-targeting drugs. Amphipathic peptides are rich sources of such membrane-interacting antivirals. Here, we report that influenza viruses were effectively inactivated by M2 AH, an amphipathic peptide derived from the M2 protein of the influenza virus. Although overall hydrophobicity (<H>) of M2 AH was not related to antiviral activity, modification of the hydrophobic moment (<μH>) of M2 AH dramatically altered the antiviral activity of this peptide. M2 MH, a derivative of M2 AH with a <μH> of 0.874, showed a half maximal inhibitory concentration (IC<SUB>50</SUB>) of 53.3 nM against the A/PR/8/34 strain (H1N1), which is 16-times lower than that of M2 AH. The selectivity index (IC<SUB>50</SUB>/CC<SUB>50</SUB>), where CC<SUB>50</SUB> is the half maximal cytotoxic concentration, was 360 for M2 MH and 81 for M2 AH. Dynamic light scattering spectroscopy and electron microscopy revealed that M2 AH-derived peptides did not disrupt liposomes but altered the shape of viruses. This result suggests that the shape of virus envelope was closely related to its activity. Thus, we propose that deforming without rupturing the membranes may achieve a high selectivity index for peptide antivirals.</P> <P><B>Highlights</B></P> <P> <UL> <LI> M2 AH is an amphipathic peptide derived from influenza virus M2 protein. </LI> <LI> M2 MH with elevated hydrophobic moment was a strong antiviral with low toxicity. </LI> <LI> M2 AH and MH did not disrupt membrane but simply deformed the shape of virus. </LI> <LI> Deformation of viral envelope may achieve a high selectivity index for peptide antivirals. </LI> </UL> </P>

End-spliced Dimeric Nanodisc for Improved Virucidal Activity of Nanoperforator

Hyunseok OH,Younghun JUNG,Seok-Oh MOON,Jaehyeon HWANG,Jinhyo CHUNG,Woo- Jae CHUNG,Dae-Hyuk KWEON 한국생물공학회 2020 한국생물공학회 학술대회 Vol.2020 No.10